JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2001
Does This Patient Have Breast Cancer?
QUESTION: The authors, in an article for the JAMA section on the rational clinical examination, consider the evidence on whether and how to use clinical breast examination as a cancer screening technique. BACKGROUND: Breast cancer is a common disease, particularly in older women. The authors note that by age 70 the annual incidence of breast cancer is one in 200 women. Breast cancer survival is strongly influenced by the stage of the disease at the time of diagnosis. As a result, it is important to consider how best to screen for this disease. In recent years there has been considerable attention in the clinical literature and in the popular media paid to the screening strategies of breast self-examination and of screening mammography, but somewhat less to the potential role of the breast examination by the healthcare provider. In actual clinical practice, the same woman may be the recipient of any, none, or all of these screening modalities. The best way to combine these screening strategies, particularly in the case of the older woman, remains a subject of some uncertainty and controversy. DATA SOURCES: Data were obtained from a MEDLINE search of the English-language literature for 1966 through 1997 and additional articles as identified by the authors. STUDY SELECTION CRITERIA: In their evaluation of the effectiveness of clinical breast examination, the authors included both controlled trials and case-controlled studies in which clinical breast examination was used as a component of the screening. Study of breast examination technique considered both clinical studies and studies using silicone breast models. DATA EXTRACTION: The combined data from the trials included information on approximately 200,000 women who received a breast cancer screening intervention (mammography and/or clinical breast examination). However, none of the studies made the direct comparison of a group receiving clinical breast examination as a sole intervention with a control group that did not receive any screening. Data on the utility of clinical breast examination were partially derived from studies where that screening modality was used in combination with mammography. MAIN RESULTS: A number of trials of cancer screening have demonstrated a reduction in mortality from the use of mammography and clinical breast examination as combined screening strategies compared with no screening, with the inference that the reduction in mortality comes from the earlier detection of breast cancer. The percentage of the detected cancers that are detected in the trials by clinical breast examination despite having been missed on mammography varies across the trials from a low of 3% of the detected cancers to a high of 45%. It is speculative whether the marginal contribution of clinical breast examination to the mortality reduction in these screening trials corresponds to the percentage of cancers detected by clinical breast examination alone. In most of the clinical trials, the technique of breast examination reportedly was not well described. It is unclear therefore how much the technique of breast examination used varied within and among the clinical trials. Data from studies using examinations of breast models made of silicone demonstrated that test performance accuracy correlated with a lengthier breast examination, better breast examination technique, and perhaps with examiner experience. The report includes data from six comparator studies and from two demonstration projects. Of the six comparator studies, four compared a screened population with an unscreened population and two compared different intensities of screening strategies. None of the eight clinical trials was directed to a geriatric population and in fact older women were excluded by upper age entry criteria from the six comparator studies. (The upper age limit for study entry in the six comparator studies varied from 49 to 64.) CONCLUSION: The authors drew on the pooled results of these eight studies to conclude that clinical breast examination has a sensitivity of 54% (95% confidence interval, 48.3,59.8) and a specificity of 94% (95% confidence interval, 90.2,96.9). The authors conclude that screening clinical breast examination should be done for women age older than 40. [source]

The Role of Benzodiazepines in the Treatment of Insomnia

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2001
Meta-Analysis of Benzodiazepine Use in the Treatment of Insomnia
PURPOSE: To obtain a precise estimate of the efficacy and common adverse effects of benzodiazepines for the treatment of insomnia compared with those of placebo and other treatments. BACKGROUND: Insomnia, also referred to as disorder of initiating or maintaining sleep, is a common problem and its prevalence among older people is estimated to be 23% to 34%.1 The total direct cost in the United States for insomnia in 1995 was estimated to be $13.9 billion.2 The complaint of insomnia in older people is associated with chronic medical conditions; psychiatric problems, mainly depression, chronic pain, and poor perceived general condition;1,3,4 and use of sleep medications.5 Thus in most cases, insomnia is due to some other underlying problem and is not just a consequence of aging.6 Accordingly, the management of insomnia should focus on addressing the primary problem and not just short-term treatment of the insomnia. Benzodiazepines belong to the drug class of choice for the symptomatic treatment of primary insomnia.7 This abstract will appraise a meta-analysis that compared the effect of benzodiazepines for short-term treatment of primary insomnia with placebo or other treatment. DATA SOURCES: Data sources included articles listed in Medline from 1966 to December 1998 and the Cochrane Controlled Trials Registry. The medical subject heading (MeSH) search terms used were "benzodiazepine" (exploded) or "benzodiazepine tranquillizers" (exploded) or "clonazepam,""drug therapy,""randomized controlled trial" or "random allocation" or "all random,""human," and "English language." In addition, bibliographies of retrieved articles were scanned for additional articles and manufacturers of brand-name benzodiazepines were asked for reports of early trials not published in the literature. STUDY SELECTION CRITERIA: Reports of randomized controlled trials of benzodiazepine therapy for primary insomnia were considered for the meta-analysis if they compared a benzodiazepine with a placebo or an alternative active drug. DATA EXTRACTION: Data were abstracted from 45 randomized controlled trials representing 2,672 patients, 47% of whom were women. Fifteen studies included patients age 65 and older and four studies involved exclusively older patients. Twenty-five studies were based in the community and nine involved inpatients. The duration of the studies ranged from 1 day to 6 weeks, with a mean of 12.2 days and median of 7.5 days. The primary outcome measures analyzed were sleep latency and total sleep duration after a sleep study, subjects' estimates of sleep latency and sleep duration, and subjects' report of adverse effects. Interrater reliability was checked through duplicate, independent abstraction of the first 21 articles. Overall agreement was between 95% and 98% (kappa value of 0.90 and 0.95 accordingly) for classification of the studies and validity of therapy, and 76% (kappa value of 0.51) for study of harmful effects. A scale of 0 to 5 was used to rate the individual reports, taking into account the quality of randomization, blinding, follow-up, and control for baseline differences between groups. Tests for homogeneity were applied across the individual studies and, when studies were found to be heterogeneous, subgroup analysis according to a predefined group was performed. MAIN RESULTS: The drugs used in the meta-analysis included triazolam in 16 studies; flurazepam in 14 studies; temazepam in 13 studies; midazolam in five studies; nitrazepam in four studies; and estazolam, lorazepam, and diazepam in two studies each. Alternative drug therapies included zopiclone in 13 studies and diphenhydramine, glutethimide, and promethazine in one study each. Only one article reported on a nonpharmacological treatment (behavioral therapy). The mean age of patients was reported in 33 of the 45 studies and ranged between 29 and 82. SLEEP LATENCY: In four studies involving 159 subjects, there was sleep-record latency (time to fall asleep) data for analysis. The pooled difference indicated that the latency to sleep for patients receiving a benzodiazepine was 4.2 minutes (95% CI = (,0.7) (,9.2)) shorter than for those receiving placebo. Patient's estimates of sleep latency examined in eight studies showed a difference of 14.3 minutes (95% CI = 10.6,18.0) in favor of benzodiazepines over placebo. TOTAL SLEEP DURATION: Analysis of two studies involving 35 patients in which total sleep duration using sleep-record results was compared indicated that patients in the benzodiazepine groups slept for an average of 61.8 minutes (95% CI = 37.4,86.2) longer than those in the placebo groups. Patient's estimates of sleep duration from eight studies (566 points) showed total sleep duration to be 48.4 minutes (95% CI = 39.6,57.1) longer for patients taking benzodiazepines than for those on placebo. ADVERSE EFFECTS: Analysis of eight studies (889 subjects) showed that those in the benzodiazepine groups were more likely than those in the placebo groups to complain of daytime drowsiness (odds ratio (OR) 2.4, 95% confidence interval (CI) = 1.8,3.4). Analysis of four studies (326 subjects) also showed that subjects in the benzodiazepine groups were more likely to complain of dizziness or lightheadedness than the placebo groups. (OR 2.6, 95% CI = 0.7,10.3). Despite the increased reported side effects in the benzodiazepine groups, drop-out rates were similar in the benzodiazepine and placebo groups. For patient reported outcome, there was no strong correlation found for sleep latency data, (r = 0.4, 95% CI = (,0.3) (,0.9)) or for sleep duration (r = 0.2, 95% CI = ,0.8,0.4) between benzodiazepine dose and outcome. COMPARISON WITH OTHER DRUGS AND TREATMENTS: In three trials with 96 subjects, meta-analysis of the results comparing benzodiazepines with zopiclone, did not show significant difference in sleep latency in the benzodiazepine and placebo groups, but the benzodiazepine groups had increased total sleep duration (23.1 min. 95% CI = 5.6,40.6). In four trials with 252 subjects, the side effect profile did not show a statistically significant difference (OR 1.5, CI 0.8,2.9). There was only one study comparing the effect of behavioral therapy with triazolam. The result showed that triazolam was more effective than behavioral therapy in decreasing sleep latency, but its efficacy declined by the second week of treatment. Behavioral therapy remained effective throughout the 9-week follow-up period. There were four small trials that involved older patients exclusively, with three of the studies having less than 2 weeks of follow-up. The results were mixed regarding benefits and adverse effects were poorly reported. CONCLUSION: The result of the meta-analysis shows that the use of benzodiazepines results in a decrease in sleep latency and a significant increase in total sleep time as compared with placebo. There was also a report of significantly increased side effects, but this did not result in increased discontinuation rate. There was no dose-response relationship for beneficial effect seen with the use of benzodiazepines, although the data are scant. Zopiclone was the only alternative pharmacological therapy that could be studied with any precision. There was no significant difference in the outcome when benzodiazepines were compared with zopiclone. There was only one study that compared the effect of benzodiazepines with nonpharmacological therapy; thus available data are insufficient to comment. [source]

Regular or "Super-Aspirins"?

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2001
A Review of Thienopyridines or Aspirin to Prevent Stroke
PURPOSE: To review the evidence for the effectiveness and safety of the thienopyridines (ticlopidine and clopidogrel) compared with aspirin for the prevention of vascular events among patients at high risk of vascular disease. BACKGROUND: Atherosclerosis and resultant cardiovascular disease are important causes of morbidity and mortality in older people. In particular, atherosclerosis of the cerebral arteries can lead to transient ischemic attacks (TIAs) and stroke. Stroke ranks as the third-leading cause of death in the United States and in 1997 was responsible for over 150,000 fatalities.1 In addition to the mortality associated with this disease, stroke is also a leading source of long-term disability in survivors. Nearly 4.5 million stroke survivors are alive today,1 highlighting the fact that primary, but also secondary, prevention are extremely important for minimizing the complications of this illness. DATA SOURCES: Specialized trial registers of the Cochrane Stroke Group and the Antithrombotic Trialist's Collaboration, MEDLINE, and Embase were searched. Additional unpublished information and data were sought from Sanofi, the pharmaceutical company that developed and manufactures ticlopidine and clopidogrel, as well as the principal investigators of the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial,7 the largest of the trials identified. STUDY SELECTION CRITERIA: All unconfounded randomized trials comparing either ticlopidine or clopidogrel with aspirin among patients at high risk of vascular disease (those with symptoms of ischemia of the cerebral, coronary, or peripheral circulations) who were followed for at least 1 month for the recurrence of vascular events were included. DATA EXTRACTION: Data were extracted from four completed randomized trials completed in the past 20 years, which included 22,656 patients.7,10 Two authors independently extracted the data from these trials for the following information: the types of patients enrolled; the entry and exclusion criteria; the randomization method; the number of patients originally allocated to the treatment and control groups; the method and duration of follow-up; the number of patients in each group lost to follow-up; information on compliance with the treatment allocated; the definitions of outcome events; the number of outcome events in each treatment group; and any method used for blinding patients, treating clinicians, and outcome assessors to treatment allocation. MAIN RESULTS: Four completed trials involving a total of 22,656 patients were identified. Aspirin was compared with ticlopidine in three trials (3,471 patients)8,10 and with clopidogrel in one trial (19,185 patients).7 A recent TIA or ischemic stroke was the qualifying event in 9,840 patients, a recent myocardial infarction in 6,302 patients, and symptomatic peripheral arterial disease in 6,514 patients. The average age of the patients was approximately 63, with approximately two-thirds of the patients being male and white. The duration of follow-up ranged from 12 to 40 months. CONCLUSIONS: This systematic review demonstrates that, compared with aspirin, thienopyridines are only modestly more effective in preventing serious vascular events in high-risk patients. For patients who are intolerant of, or allergic to aspirin, the available safety and efficacy data suggest that clopidogrel is an appropriate, but more-expensive, alternative antiplatelet drug. It appears safer than ticlopidine and as safe as aspirin but it should not replace aspirin as the first-choice antiplatelet agent for all patients. Further studies are necessary to determine which, if any, particular types of patients would benefit most and least from clopidogrel instead of aspirin. [source]

MICROWAVE-ASSISTED EXTRACTION OF CAPSAICINOIDS FROM CAPSICUM FRUIT

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2004
OPAL J. WILLIAMS
The applicability of microwave irradiation to assist the extraction of capsaicinoids from capsicum fruit was investigated. The procedure involved irradiation of 2 g samples in a closed-vessel followed by gas chromatography of capsaicinoid derivatives. The optimum conditions for extraction were determined to be acetone at 30% power for 7 min irrespective of ground or whole tissue. The yield of the compounds extracted was significantly greater (P < 0.05) using microwave-assisted extraction (MAE) compared to traditional reflux and shaken flask methods. A single extraction step was efficient in recovering approximately 95% of the total capsaicinoid fraction in 15 min compared with 2 h for the reflux and 24 h for the shaken flask methods. Due to the considerable savings in time and energy as well as reliability, this technique is suitable for fast extraction of capsaicinoids from large samples. [source]

APPLICATION OF ULTRASONICATION OR HIGH-PRESSURE EXTRACTION OF FLAVONOIDS FROM LITCHI FRUIT PERICARP

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2009
K. NAGENDRA PRASAD
ABSTRACT Litchi (Litchi chinensis Sonn.) fruit pericarp (LFP) contains a high amount of flavonoids, which could be used as natural antioxidants. Some emerging novel technologies, such as ultrasonic extraction (UE) and high-pressure extraction (HPE), have exhibited great potential for flavonoid extraction. Experiments were conducted to comparatively investigate the effects of conventional extraction (CE), 40-KHz UE and 200- or 400-MPa HPE on the extraction efficiency of flavonoids from LFP. After 30 min of extraction, the extract yield, total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide anion scavenging ability were examined. The crude extract yields by the UE, 400 HPE and CE were 24, 30 and 1.83%, respectively. However, there were no significant differences (P > 0.05) in the total phenolic content and antioxidant activity tested among these three different extractions at the same concentration. In addition, two flavonoids, namely epicatechin and epicatechin gallate, were identified and quantified as the major compounds, while catechin and procyanidin B2 were identified as the minor compounds. The total flavonoid content detected was 0.65, 0.75, 0.29 and 0.07 mg/g dry weight by HPE at 200 and 400 MPs, UE, and CE, respectively. Thus, the HPE technique showed a higher efficiency in extracting flavonoids from LFP, and the HPE could reduce the extraction time and increase the amount of the extracted phenolics. PRACTICAL APPLICATIONS Litchi (Litchi chinensis Sonn.) is a subtropical fruit that originated in Southeast Asia. As litchi fruit is gradually accepted by consumers for its delicious taste and attractive red skin, litchi production has steadily increased in recent decades, with increasing exports to Europe and North America from both the southern and northern hemisphere production areas. Litchi fruit pericarp (LFP) accounts for approximately 16% by weight of the whole fresh fruit and is comprised of a significant amount of flavonoids. Therefore, LFP tissues may be considered an important source of dietary flavonoids. This work showed that HPE technique has a high efficiency in extracting flavonoids from LFP tissues, which may help the litchi industry develop new extraction methods to better utilize the flavonoids from LFP tissues. [source]

ANALYSIS OF VARIABLES AND MODELING OF GEVUINA AVELLANA OIL EXTRACTION WITH ETHANOL NEAR AZEOTROPE CONDITIONS

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2009
DANIEL FRANCO
ABSTRACT Oil extraction from Gevuina avellana Mol. (Chilean hazelnut) with ethanol, near the conditions of its azeotrope with water, was carried out in this work. The effects of solubility, liquid-to-solid ratio and moisture content of ethanol were studied using 92% ethanol, azeotropic (96%) and absolute ethanol (99.9%) as solvents. Water content had a high effect on oil solubility, which reached 140 g/L in 99.9% ethanol, whereas it was 40 g/L with azeotropic ethanol. Oil accounted for 93% of total extractable compounds with absolute ethanol. Kinetics studies of the extraction process were performed at 50C, giving as a result apparent diffusivity values near 10,11 m2/s, being the highest values obtained for ethanol 92% (7.5,16 × 10,11). It was also found that the higher the liquid-to-solid ratio, the higher the diffusivity. Simulation of four-stage countercurrent extraction with azeotropic ethanol yielded 23.5% oil extraction, whereas simulation of four-stage cross-flow extraction yielded 40.7%. Ethanol can be an alternative to batch cold pressing or hexane solvent extraction, for G. savellana seeds or meal processing. PRACTICAL APPLICATIONS The results presented in this paper are applicable for obtaining oil from oilseeds by extraction with ethanol. It includes relevant results for the optimization of extraction conditions and particularly those regarding liquid-to-solid ratio and percentage of water. Considering the more specific focus of this research, the results are applicable to obtaining Gevuina avellana oil by using an ethanol-based process, which will allow to avoid one of the cold-pressing process drawbacks: the high oil content of the meal, which is a factor limiting its lifetime. [source]

SUBCRITICAL WATER EXTRACTION OF CAFFEINE FROM BLACK TEA LEAF OF IRAN

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2008
ANVAR SHALMASHI
ABSTRACT This study examines subcritical water extraction (SCWE) of caffeine from black tea leaf. The effects of various operating conditions such as water temperature (100, 125, 150 and 175C), water flow rate (1, 2 and 4 g/min), mean particle size (0.5, 1 and 2 mm) on extraction yield and rate were determined. SCWE at 175C, water flow rate of 2 g/min and mean particle size of 0.5 mm were found to be able to recover 3.82% (w/w) of caffeine present in the black tea leaf within 3 h of extraction. In comparison to the SCWE, conventional hot water extraction showed 3.30% (w/w) extraction yield. It was found also that pressure had no effect on extraction yield and rate. PRACTICAL APPLICATIONS Recently, subcritical water has become of great interest as an alternative solvent for extraction of natural active compounds. Subcritical water, as a green solvent, can be used in many different fields of applications. In recent years, extraction of flavors, fragrances and antioxidant components from plant materials, and hydrolysis of carbohydrates, vegetable oils and fatty acids have been widely investigated by many researchers. Using subcritical water for analytical purposes, for soil remediation and applying it as a reaction media are some other interesting fields for practical applications. Subcritical water is an excellent solvent for caffeine as well as many other organic compounds but is safer than the organic solvents that are used for caffeine extraction. [source]

SUPERCRITICAL FLUID EXTRACTION AND DETERMINATION OF LUTEIN IN HETEROTROPHICALLY CULTIVATED CHLORELLA PYRENOIDOSA

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2007
ZHENGYUN WU
ABSTRACT Chlorella is a promising alternative resource of lutein, as it can be cultivated heterotrophically and efficiently in a fermentor. In this study, high density of Chlorella pyrenoidosa was achieved by fed-batch cultivations. Lutein in Chlorella was extracted by supercritical fluid and was determined by high-performance liquid chromatography and liquid chromatography-mass spectrometry. The extraction degree of lutein reached 87.0% after 4-h extraction under the optimized conditions of 50C, 25 MPa and modified CO2 with 50% ethanol. High purity of lutein could be obtained by supercritical fluid extraction with appropriate operation parameters. The whole process developed in this study may be useful for the commercial production of lutein. [source]

EFFECT OF CENTRIFUGAL FORCE ON THE AQUEOUS EXTRACTION OF SOLUTE FROM SUGAR BEET TISSUE PRETREATED BY A PULSED ELECTRIC FIELD

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2005
KAMAL EL-BELGHITI
ABSTRACT In this article, the centrifugal aqueous extraction of solute from sugar beet tissue is investigated at ambient temperature after a pulsed electric field (PEF) treatment. Two kinds of samples of fresh sugar beet were used: a sample with a determined discoid shape and gratings. Both samples were pretreated by a PEF with 250 rectangular pulses of 100 µS each. The PEF intensity was fixed at 940 V/cm for the disk samples and 670 V/cm for gratings. The pretreated samples were placed in distilled water at ambient temperature with a water-to-solid ratio equal to 3 and subjected to different centrifugal accelerations. The centrifugal field significantly enhanced the kinetics of extraction from the electrically pretreated tissues of sugar beet. However, the increase of centrifugal acceleration was only effective up to a certain value (5430 × g for disk samples and 600 × g for gratings). The centrifugal extraction can be assumed to proceed in two stages: a first rapid washing followed by a slow diffusion stage. A two-exponential kinetics model taking into account these two stages was applied and correctly described the centrifugal extraction from beet samples (disks and gratings). [source]

SUPERCRITICAL CO2/ETHANOL EXTRACTION OF ASTAXANTHIN FROM BLUE CRAB (CALLINECTES SAPIDUS) SHELL WASTE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2001
LETICIA FÉLIX-VALENZUELA
ABSTRACT Astaxanthin (AX) is the major naturally occurring carotenoid pigment in marine crustaceans and the flesh of salmonids. These organisms are unable to synthesize AX de novo and when farmed commercially, require it in their feed. The high cost of synthetic AX has promoted research into new natural sources of ihe pigment, such as crustacean wastes. In this work, AX from demineralized crab (Callinectes sapidusj shell waste was extracted with a mixture of supercritical C2 and ethanol as a cosolvent. The effect of total solids load, pressure and temperature was assessed by response surface methodology (RSM). Extracted AX was determined by HPLC. The experimental data were fined to a second order model whereby the conditions for maximum extraction yield were defined (, 34 MPa, 45C and solids load of 25 g). Pressure and solids load were the most important factors affecting AX extraction yields. [source]

ENZYMATIC HYDROLYSIS OF SOYBEAN FOR SOLVENT AND MECHANICAL OIL EXTRACTION

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2000
PRAVEEN C. BARGALE
ABSTRACT Due to inefficient extractability of its low oil content, soybeans are often bypassed in village-scale processing. Soygrits, flakes, and expanded collets were hydrolyzed by proteases, cellulases, and pectinases before oil extraction by solvent and static mechanical pressure. Driselase with multi-enzyme activity and two proteases improved solvent extraction rates but only Driselase enhanced mechanical pressing. Up to 58% of seed oil was pressed from enzyme-hydrolyzed flakes but 88% was pressed from Driselase-treated collets. Either pretreatment is a feasible adjunct to mechanical pressing in small batch operations. [source]

APPLICATION OF EXPERIMENTAL DESIGN METHOD TO THE OIL EXTRACTION FROM OLIVE CAKE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2009
SMAIL MEZIANE
ABSTRACT Olive cake is an important solid waste of the olive oil production. It still contains a certain quantity of oil that can be recovered by means of solvent extraction. In this study, two-level full factorial design was performed to evaluate the effects of four variables and their interactions on the oil extraction by the ethanol 96.0% in a batch reactor. The variables included size of particles, temperature, and time of contact and solvent-to-solids ratio. The statistical analysis of the experimental data showed that the extracted oil mass depends on all the examined variables. It also depends on the interactions between size of particles and solvent-to-solid ratio and size of particles and temperature. The experimental data were in good agreement with those predicted by the model. PRACTICAL APPLICATIONS Olive cake is solid waste of the olive oil industry that is available in large amounts in many Mediterranean countries and at very low cost. It can be treated or valorized, enabling at the same time the solution to environmental problems caused by the olive oil production process. The economic interest that it presents is especially because of the residual oil that it contains and that can be recovered by solvent extraction. However, this solid,liquid extraction depends on several parameters: the ones inherent to the products (structure and properties of the sample, nature of extraction solvent); and the others to the extraction process (time of contact, temperature of extraction, solvent-to-solid ratio, stirring velocity). The experimental design method enables to determine the most important variables and their interaction in the extraction process at the same time performing a low number of experiments. [source]

Sensitivity of superficial cultures in lower extremity wounds,

JOURNAL OF HOSPITAL MEDICINE, Issue 7 2010
Chayan Chakraborti MD
Abstract BACKGROUND: Superficial wound cultures are routinely used to guide therapy, despite a lack of clear supporting evidence. PURPOSE: To conduct a systematic review of the correlation between superficial wound cultures and the etiology of skin and soft tissue infections. DATA SOURCES: Medline, EMBASE, CINAHL, Scopus. STUDY SELECTION: Articles published between January 1960 and August 2009 involving superficial wound cultures and deeper comparison cultures. DATA EXTRACTION: Two reviewers independently searched for abstracted information pertaining to the microbiology of lower extremity wounds sufficient to calculate the sensitivity and specificity of superficial wound cultures versus comparison cultures. DATA SYNTHESIS: Data pooled using a random-effects meta-analysis model. RESULTS: Of 9032 unique citations, 8 studies met all inclusion criteria. Inter-rater reliability was substantial (Kappa = 0.78). Pooled test sensitivity for superficial wound swabs was 49% (95% confidence interval [CI], 37-61%], and specificity was 62% (95% CI, 51-74%). The pooled positive and negative likelihood ratios (LRs) were 1.1 (95% CI, 0.71-1.5) and 0.67 (95% CI, 0.52-0.82). The median number of isolates for surface cultures (2.7, interquartile range [IQR] 1.8-3.2) was not significantly different than that for comparison cultures, (2.2, IQR 1.7-2.9) (P = 0.75). CONCLUSION: Few studies show a strong relationship between superficial wound swabs and deep tissue cultures, and the current data demonstrate poor overall sensitivity and specificity. The positive and negative LRs were found to provide minimal utility in influencing pretest probabilities. Results of this analysis show that wound cultures should not be used in lieu of local antibiograms to guide initial antibiotic therapies. Journal of Hospital Medicine 2010;5:415,420. © 2010 Society of Hospital Medicine. [source]

Effect of hospitalist attending physicians on trainee educational experiences: A systematic review,

JOURNAL OF HOSPITAL MEDICINE, Issue 8 2009
Pradeep Natarajan MD
Abstract BACKGROUND: Trainees receive much of their inpatient education from hospitalists. PURPOSE: To characterize the effects of hospitalists on trainee education. DATA SOURCES: MEDLINE, Database of Reviews of Effectiveness (DARE), National Health Service (NHS) Economic Evaluation Database (EED), Health Technology Assessment (HTA), and the Cochrane Collaboration Database (last searched October 2008) databases using the term "hospitalist", and meeting abstracts from the Society of Hospital Medicine (SHM) (2002-2007), Society of General Internal Medicine (SGIM) (2001-2007), and Pediatric Academic Societies (PAS) (2000-2007). STUDY SELECTION: Original English language research studies meeting all of the following: involvement of hospitalists; comparison to nonhospitalist attendings; evaluation of trainee knowledge, skills, or attitudes. 711 articles were reviewed, 32 retrieved, and 6 included; 7,062 meeting abstracts were reviewed, 9 retrieved, and 2 included. DATA EXTRACTION: Two authors reviewed articles to determine study eligibility. Three authors independently reviewed included articles to abstract data elements and classify study quality. DATA SYNTHESIS: Seven studies were quasirandomized one was a noncontemporaneous comparison. All citations only measured trainee attitudes. In all studies comparing hospitalists to nonhospitalists, trainees were more satisfied with hospitalists overall, and with other aspects of their teaching, but ratings were high for both groups. One of 2 studies that distinguished nonhospitalist general internists from specialists showed that trainees preferred hospitalists, but the other did not demonstrate a hospitalist advantage over general internists. CONCLUSIONS: Trainees are more satisfied with inpatient education from hospitalists. Whether the increased satisfaction translates to improved learning is unclear. Journal of Hospital Medicine 2009;4:490,498. © 2009 Society of Hospital Medicine. [source]

Effects of rapid response systems on clinical outcomes: Systematic review and meta-analysis

JOURNAL OF HOSPITAL MEDICINE, Issue 6 2007
Sumant R. Ranji MD
Abstract BACKGROUND A rapid response system (RRS) consists of providers who immediately assess and treat unstable hospitalized patients. Examples include medical emergency teams and rapid response teams. Early reports of major improvements in patient outcomes led to widespread utilization of RRSs, despite the negative results of a subsequent cluster-randomized trial. PURPOSE To evaluate the effects of RRSs on clinical outcomes through a systematic literature review. DATA SOURCES MEDLINE, BIOSIS, and CINAHL searches through August 2006, review of conference proceedings and article bibliographies. STUDY SELECTION Randomized and nonrandomized controlled trials, interrupted time series, and before-after studies reporting effects of an RRS on inpatient mortality, cardiopulmonary arrests, or unscheduled ICU admissions. DATA EXTRACTION Two authors independently determined study eligibility, abstracted data, and classified study quality. DATA SYNTHESIS Thirteen studies met inclusion criteria: 1 cluster-randomized controlled trial (RCT), 1 interrupted time series, and 11 before-after studies. The RCT showed no effects on any clinical outcome. Before-after studies showed reductions in inpatient mortality (RR = 0.82, 95% CI: 0.74-0.91) and cardiac arrest (RR = 0.73, 95% CI: 0.65-0.83). However, these studies were of poor methodological quality, and control hospitals in the RCT reported reductions in mortality and cardiac arrest rates comparable to those in the before-after studies. CONCLUSIONS Published studies of RRSs have not found consistent improvement in clinical outcomes and have been of poor methodological quality. The positive results of before-after trials likely reflects secular trends and biased outcome ascertainment, as the improved outcomes they reported were of similar magnitude to those of the control group in the RCT. The effectiveness of the RRS concept remains unproven. Journal of Hospital Medicine 2007;2:422,432. © 2007 Society of Hospital Medicine. [source]

DECREASE IN DYNAMIC VISCOSITY AND AVERAGE MOLECULAR WEIGHT OF ALGINATE FROM LAMINARIA DIGITATA DURING ALKALINE EXTRACTION,

JOURNAL OF PHYCOLOGY, Issue 2 2008
Peggy Vauchel
Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1,4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted alginates. [source]

A NEW METHOD FOR EXTRACTION, ISOLATION AND TRANSESTERIFICATION OF FREE FATTY ACIDS FROM ARCHAEOLOGICAL POTTERY

ARCHAEOMETRY, Issue 5 2010
M. W. GREGG
This paper presents evidence for increased recovery of organic residues from archaeological pottery through use of a microwave-assisted liquid chromatography protocol. C16:0 and C18:0 saturated fatty acids were obtained from archaeological potsherds recovered from nine Neolithic settlements in the Middle East dating between 4700 and 7300 cal bc, including materials that had not produced evidence for the survival of any lipid species through use of ,conventional' solvent extraction techniques. Compound-specific isotopic analyses of C16:0 and C18:0 fatty acids in potsherd extracts subsequently revealed ,13C/,12C compositions consistent with modern subcutaneous fats of wild boar and goats pastured on lands adjacent to the Jordan Valley, and residues from a modern pottery vessel used in the manufacturing of butter, cheese and yogurt in central Turkey. These results are presented as an illustration of capabilities of the microwave-assisted recovery protocol. The reclamation of saturated and unsaturated fatty acids from archaeological pottery fragments recovered from a number of the earliest ceramic horizons in the Middle East is herewith reported, and the extraction methods and instrumental analytical techniques are described. [source]

Multi-scale Feature Extraction on Point-Sampled Surfaces

COMPUTER GRAPHICS FORUM, Issue 3 2003
Mark Pauly
We present a new technique for extracting line-type features on point-sampled geometry. Given an unstructuredpoint cloud as input, our method first applies principal component analysis on local neighborhoods toclassify points according to the likelihood that they belong to a feature. Using hysteresis thresholding, we thencompute a minimum spanning graph as an initial approximation of the feature lines. To smooth out the featureswhile maintaining a close connection to the underlying surface, we use an adaptation of active contour models.Central to our method is a multi-scale classification operator that allows feature analysis at multiplescales, using the size of the local neighborhoods as a discrete scale parameter. This significantly improves thereliability of the detection phase and makes our method more robust in the presence of noise. To illustrate theusefulness of our method, we have implemented a non-photorealistic point renderer to visualize point-sampledsurfaces as line drawings of their extracted feature curves. [source]

Feature Extraction for Traffic Incident Detection Using Wavelet Transform and Linear Discriminant Analysis

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2000
A. Samant
To eliminate false alarms, an effective traffic incident detection algorithm must be able to extract incident-related features from the traffic patterns. A robust feature-extraction algorithm also helps reduce the dimension of the input space for a neural network model without any significant loss of related traffic information, resulting in a substantial reduction in the network size, the effect of random traffic fluctuations, the number of required training samples, and the computational resources required to train the neural network. This article presents an effective traffic feature-extraction model using discrete wavelet transform (DWT) and linear discriminant analysis (LDA). The DWT is first applied to raw traffic data, and the finest resolution coefficients representing the random fluctuations of traffic are discarded. Next, LDA is employed to the filtered signal for further feature extraction and reducing the dimensionality of the problem. The results of LDA are used as input to a neural network model for traffic incident detection. [source]

Extent of Nontimber Resource Extraction in Tropical Forests: Accessibility to Game Vertebrates by Hunters in the Amazon Basin

CONSERVATION BIOLOGY, Issue 2 2003
Carlos A. Peres
We conducted a basin-wide geographic information system analysis of the nonmotorized accessibility of Amazonian NTFP extraction and estimated the proportion of the Amazon drainage basin within Brazil ( 3.74 million km 2 ) that can be accessed on foot from the nearest navigable river or functional road. We use a long-term series of standardized line-transect vertebrate censuses conducted throughout the region to illustrate the effects of physical accessibility on wildlife densities in terms of hunting pressure as a function of distance from the nearest point of access. Population abundance in large-bodied, prime-target species preferred by game hunters tended to increase at greater distances from the access matrix, whereas small-bodied species ignored by hunters usually showed the reverse trend. In addition, we estimated the proportion of presumably inviolate core areas within nature, extractive, and indigenous reserves of Brazilian Amazonia that are prohibitively remote and unlikely to be overhunted; for instance, only 1.16% of the basin-wide area is strictly protected on paper and is reasonably safe from extractive activities targeted to game vertebrates and other valuable NTFPs. Finally, we discuss the concept of truly undisturbed wildlands in the last major tropical forest regions by distinguishing potentially overharvested areas from those that remain largely or entirely pristine and that maintain viable populations of a full complement of harvest-sensitive species. Resumen: Las actividades de extracción enfocadas en un amplio rango de productos forestales no maderables ( NTFPs ) son omnipresentes en los bosques tropicales. Sin embargo, la extensión de bosques estructuralmente intactos en una determinada región afectada por esta forma de perturbación críptica ha sido escasamente documentada. Realizamos un análisis GIS del acceso no motorizado para la extracción NTFP en el Amazonas y estimamos la proporción de la desembocadura de la cuenca amazónica ( ,3.74 millones de km2 ) a la cual se puede acceder a pie a partir del río navegable o la carretera funcional más cercana. Utilizamos series de censos de vertebrados a largo plazo empleando transectos en línea estandarizados a lo largo de la región para ejemplificar los efectos del acceso físico sobre las densidades de vida silvestre en términos de presión de caza como función de la distancia al punto de acceso más cercano. La abundancia poblacional de especies de cuerpo grande que son blancos preferidos por los cazadores tendió a crecer a mayores distancias de la matriz de acceso, mientras que las especies de cuerpo pequeño ignoradas por los cazadores generalmente muestran la tendencia inversa. Además, estimamos la proporción de áreas medulares presuntamente inviolables dentro de las reservas naturales, extractivas e indígenas del Amazonas brasileño que son prohibitivamente remotas y poco probables de ser sobreexplotadas: por ejemplo, solo el 1.16% del área de la cuenca estrictamente proyectada en papel está razonablemente a salvo de las actividades extractivas de los vertebrados de caza y otras NTFPs valiosas. Finalmente, discutimos el concepto de tierras silvestres verdaderamente no perturbadas en las grandes regiones de bosque tropical restantes diferenciando las áreas potencialmente sobreexplotadas de aquellas que son en su mayor parte o totalmente prístinas y que mantienen poblaciones viables de un complemento total de especies sensibles a la cosecha. [source]

Deletion of mdmB impairs mitochondrial distribution and morphology in Aspergillus nidulans

CYTOSKELETON, Issue 2 2003
Katrin V. Koch
Abstract Mitochondria form a dynamic network of interconnected tubes in the cells of Saccharomyces cerevisiae or filamentous fungi such as Aspergillus nidulans,Neurospora crassa, or Podospora anserina. The dynamics depends on the separation of mitochondrial fragments, their movement throughout the cell, and their subsequent fusion with the other parts of the organelle. Interestingly, the microtubule network is required for the distribution in N. crassa and S. pombe, while S. cerevisiae and A. nidulans appear to use the actin cytoskeleton. We studied a homologue of S. cerevisiae Mdm10 in A. nidulans, and named it MdmB. The open reading frame is disrupted by two introns, one of which is conserved in mdm10 of P. anserina. The MdmB protein consists of 428 amino acids with a predicted molecular mass of 46.5 kDa. MdmB shares 26% identical amino acids to Mdm10 from S. cerevisiae, 35% to N. crassa, and 32% to the P. anserina homologue. A MdmB-GFP fusion protein co-localized evenly distributed along mitochondria. Extraction of the protein was only possible after treatment with a non-ionic and an ionic detergent (1% Triton X-100; 0.5% SDS) suggesting that MdmB was tightly bound to the mitochondrial membrane fraction. Deletion of the gene in A. nidulans affected mitochondrial morphology and distribution at 20°C but not at 37°C. mdmB deletion cells contained two populations of mitochondria at lower temperature, the normal tubular network plus some giant, non-motile mitochondria. Cell Motil. Cytoskeleton 55:114,124, 2003. © 2003 Wiley-Liss, Inc. [source]

Intraoral Extraction of Cheek Skin Cyst

DERMATOLOGIC SURGERY, Issue 12 2005
Richard Bennett MD
Background. When a physician encounters a benign subcutaneous cyst in the cheek, his or her decision whether to excise and how to excise the cyst takes into account the potential risk of postsurgical scarring. Objective. To describe and show an intraoral buccal mucosal approach to excising a cyst in the inferior-anterior cheek so that skin scarring is avoided. Method. An incision was made intraorally in the buccal mucosa, and dissection was carried through the buccinator muscle until the cyst wall was seen. Careful separation of tissue around the cyst was done by blunt dissection, and the unruptured cyst was removed through the buccal mucosal incision. Result. The entire intact cyst was removed without creating any excision marks in the cheek skin. No complications were encountered, and buccal mucosal healing was excellent. Conclusion. A buccal mucosal intraoral approach is an alternative to a percutaneous excision to remove a cyst in the lower cheek region. The intraoral approach avoids a visible scar on the cheek skin. RICHARD BENNETT, MD, MUBA TAHER, MD, AND JUSTINE YUN, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]

Minimal-Scar Segmental Extraction of Lipomas: Study of 122 Consecutive Procedures

DERMATOLOGIC SURGERY, Issue 1 2005
Rajiv Y. Chandawarkar MD
Background Surgical extirpation of lipomas that occur in cosmetically conspicuous areas of the body leaves a visible scar that is usually disfiguring. Minimal-scar segmental extraction (MSE) employs a much smaller incision and extraction and is particularly useful in exposed parts of the body. It can be easily performed in an office setting. Objective The objective of this study was to evaluate the merits of MSE in clinical practice. Unlike other reports in the literature that describe, anecdotally, minimally invasive methods of lipoma removal, our study examined a new method by carefully measuring the results in a larger group of consecutive patients treated using this technique. Materials and Methods A retrospective study was performed using data from 91 consecutive patients with a total of 122 lipomas that were treated using MSE. MSE of lipomas consists of a small stab incision and blind dissection of the tumor followed by its extraction in a segmental fashion. This procedure involves small instrumentation, minimal dissection with preservation of contour, and complete removal of the lipoma, including substantial portions of the capsule. Clinical data, including complications, outcomes, and recurrence rates, were recorded. Results The procedure was well tolerated by patients, who were pleased with the results, particularly the small scar. The incidence of complications was 1.6% (n= 2) and consisted of hematoma (n= 1) and seroma (n= 1). The recurrence rate was 0.8% (n= 1). No long-term morbidity was noted. Conclusions The technical ease with which the MSE can be performed, coupled with a low recurrence rate, makes it a very cost-effective operation. The smaller postoperative scars, rapid healing, and low morbidity allow for better patient acceptance. We recognize the advantages and limitations of this procedure and encourage its use in selected patients. RAJIV Y. CHANDAWARKAR, MD, PEDRO RODRIGUEZ, MD, JOHN ROUSSALIS, MD, AND M. DEVIPRASAD TANTRI, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]

Follicular Unit Extraction: Minimally Invasive Surgery for Hair Transplantation

DERMATOLOGIC SURGERY, Issue 8 2002
William R. Rassman MD
background. Follicular Unit Transplantation (FUT) is performed using large numbers of naturally occuring individual follicular units obtained by single-strip harvesting and stereo-microscopic dissection. Donor wound scarring from strip excision, although an infrequent complication, still concerns enough patients that an alternative solution is warranted. objective. The purpose of this paper is to introduce Follicular Unit Extraction (The FOX Procedure), in which individual follicular units are removed directly from the donor region through very small punch excisions, and to describe a test (The FOX Test) that determines which patients are candidates for this procedure. This paper explores the nuances, limitations, and practical aspects of Follicular Unit Extraction (FUE). methods. FUE was performed using 1-mm punches to separate follicular units from the surrounding tissue down to the level of the mid dermis. This was followed by extraction of the follicular units with forceps. The FOX test was developed to determine which patients would be good candidates for the procedure. The test was performed on 200 patients. Representative patients who were FOX-positive and FOX-negative were studied histologically. results. The FOX Test can determine which patients are suitable candidates for FUE. Approximately 25% of the patients biopsied were ideal candidates for FUE and 35% of the patients biopsied were good candidates for extraction. conclusion. FUE is a minimally invasive approach to hair transplantation that obviates the need for a linear donor incision. This technique can serve as an important alternative to traditional hair transplantation in certain patients. [source]

The effect of bidirectional flow on tidal channel planforms

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2004
Sergio Fagherazzi
Abstract Salt marsh tidal channels are highly sinuous. For this project, ,eld surveys and aerial photographs were used to characterize the planform of tidal channels at China Camp Marsh in the San Francisco Bay, California. To model the planform evolution, we assume that the topographic curvature of the channel centreline is a key element driving meander migration. Extraction of curvature data from a planimetric survey, however, presents certain problems because simple calculations based on equally distanced points on the channel axis produce numerical noise that pollutes the ,nal curvature data. We found that a spline interpolation and a polynomial ,t to the survey data provided us with a robust means of calculating channel curvature. The curvature calculations, combined with data from numerous cross-sections along the tidal channel, were used to parameterize a computer model. With this model, based on recent theoretical work, the relationship between planform shape and meander migration as well as the consequences of bidirectional ,ow on planform evolution have been investigated. Bank failure in vegetated salt marsh channels is characterized by slump blocks that persist in the channel for several years. It is therefore possible to identify reaches of active bank erosion and test model predictions. Our results suggest that the geometry and evolution of meanders at China Camp Marsh, California, re,ect the ebb-dominated regime. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Determination of Diclofenac in Urine Samples by Molecularly-Imprinted Solid-Phase Extraction and Adsorptive Differential Pulse Voltammetry

ELECTROANALYSIS, Issue 15 2007
Laura Fernández-Llano
Abstract A molecularly imprinted polymer for diclofenac (DCF) was prepared by thermal polymerization over silica beads using 2-(dimethylamino)ethyl-methacrylate as functional monomer. After silica elimination by HF treatment, the polymer was applied to the selective solid-phase extraction of the drug from urine followed by its quantification by adsorptive differential pulse voltammetry. Results indicate that the drug could be selectively extracted from the sample and quantified at clinically relevant concentrations (,g/mL). [source]

Protein extraction for 2-DE from the lamina of Ecklonia kurome (laminariales): Recalcitrant tissue containing high levels of viscous polysaccharides

ELECTROPHORESIS, Issue 3 2008
Kouhei Nagai
Abstract Extraction of proteins from the tissues of laminarialean algae, i.e. kelp, is difficult due to high levels of nonprotein interfering compounds, mainly viscous polysaccharides. To establish proteomic analysis of kelp species, an ethanol/phenol extraction method was developed and compared to other popular methods. Proteins were extracted with phenol from crude protein powder, obtained by homogenizing the kelp tissues in ice-cold ethanol. The ethanol/phenol method produced high-quality proteins of the highest purity from the lamina of Ecklonia kurome, one of the Japanese dominant laminarialean algae. This method gave well-resolved 1-D SDS-PAGE or 2-DE images with low background and the highest number of bands or spots. In particular, proteins with neutral to basic pI,s were efficiently extracted. Furthermore, 27 spots on the 2-DE gel were extensively identified by MALDI-TOF/TOF analysis. To the best of our knowledge, this is the first report of a protocol for protein extraction from kelp tissues that gives satisfactory 2-D protein profiles. It is expected that the protocol can be applied to other algae tissues or other recalcitrant plant tissues containing high levels of nonprotein interfering compounds. [source]

Extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from Cylindrospermopsis raciborskii

ENVIRONMENTAL TOXICOLOGY, Issue 5 2001
R. L. G. Norris
Abstract The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 391,396, 2001 [source]

A simple Tenax® extraction method to determine the availability of sediment-sorbed organic compounds

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2001
Gerard Cornelissen
Abstract A simple method to determine the availability of sediment-sorbed organic contaminants was developed and validated. For 10 polycyclic aromatic hydrocarbons, 4 polychlorinated biphenyls, and 9 chlorobenzenes in 6 sediments, we measured the fraction extracted by Tenax® in 6 and 30 h. These fractions were compared with the rapidly desorbing fractions determined by consecutive Tenax extraction. Extraction by Tenax for 30 h completely removed the rapidly desorbing fraction plus some part of the slowly desorbing fraction. The fraction removed after 30 h was about 1.4 times the rapidly desorbing fraction. The fraction extracted by Tenax after 6 h is about 0.5 times the rapidly desorbing fraction for chlorobenzenes (CBs)/polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). The rapidly desorbing fraction probably represents the fraction of sorbed organic compound that poses actual risks for transport to (ground) water and determines the uptake by organisms and that can be microbially degraded. Extraction by Tenax for 6 h provides an easy way to address these issues more accurately than does the measurement of total concentrations. [source]

Standing oral extraction of cheek teeth in 100 horses (1998-2003)

EQUINE VETERINARY JOURNAL, Issue 2 2005
P. M. DIXON
Summary Reasons for performing study: Extraction of cheek teeth (CT) by the conventional repulsion technique requires general anaesthesia and carries a high rate of post operative complications. Consequently, an alternative method of extraction, i.e. orally in standing horses, was evaluated. Hypothesis: The need for and risks of general anaesthesia could be avoided and post extraction sequelae reduced by performing extractions orally in standing horses. Methods: One hundred mainly younger horses (median age 8, range 2-18 years) with firmly attached CT that required extraction because of apical infections, displacements, diastemata, idiopathic fractures and the presence of supernumerary CT had the affected teeth (n = 111) extracted orally under standing sedation. Follow-up information was obtained for all cases, a median of 16 months later. Results: Oral extraction was successful in 89 horses and unsuccessful in 11 due to damage to the CT clinical crown (n = 9) during extraction, for behavioural reasons (n = 1) and because the apex of a partly extracted CT fell back into the alveolus following sectioning (n = 1). Predispositions to extraction-related CT fractures were present in 5 of the 9 cases, i.e. advanced dental caries (n = 2) and pre-existing ,idiopathic' fractures (n = 3). The iatrogenically fractured CT were later repulsed under standing sedation (n = 3) and under general anaesthesia (n = 6). Eighty-one of the remaining 89 horses had successful oral CT extraction with no or minimal intra- or post operative complications occurring. Post operative complications in the other 8 cases included post extraction alveolar sequestration (n = 3), alveolar sequestration and localised osteomyelitis (n = 1), localised osteomyelitis (n = 1), incorporation of alveolar packing material into alveolar granulation tissue (n = 1), and nasal discharge due to continued intranasal presence of purulent food material (n = 1) and to ongoing sinusitis (n = 1). The above sequelae were treated successfully in all cases, with general anaesthesia required in just one case. Following oral extraction, significantly (P<0.001) fewer post operative problems developed in 54 horses with apically infected CT in comparison with 71 previous cases that had repulsion of apically infected CT at our clinic. Conclusions and potential relevance: Oral extraction of cheek teeth is a successful technique in the majority of younger horses with firmly attached CT and greatly reduces the post operative sequelae, compared with CT repulsion. Additionally, the costs and risks of general anaesthesia are avoided. Further experience and refinement in the described protocol could potentially increase the success of this procedure and also reduce the incidence of post operative sequelae. [source]