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Possible Mechanism (possible + mechanism)
Kinds of Possible Mechanism Terms modified by Possible Mechanism Selected AbstractsTEMPERATURE-VISCOSITY RELATIONS OF BOWHEAD WHALE BLOOD: A POSSIBLE MECHANISM FOR MAINTAINING COLD BLOOD FLOWMARINE MAMMAL SCIENCE, Issue 2 2004Robert Elsner [source] A Kindling Model of Pharmacoresistant Temporal Lobe Epilepsy in Sprague,Dawley Rats Induced by Coriaria Lactone and Its Possible MechanismEPILEPSIA, Issue 4 2003Ying Wang Summary: ,Purpose: The aim of this study was to develop a new animal model of pharmacoresistant temporal lobe epilepsy (TLE) by repeated intramuscular injection of Coriaria lactone (CL) at subthreshold dosages and to explore the mechanisms that might be involved. Methods: Healthy male Sprague,Dawley rats (n = 160) were randomized into four groups during the kindling process: three groups (n = 50 for each group) received CL injection at subthreshold dosages (1.25, 1.5, and 1.75 mg/kg, respectively), and ten received normal saline (NS) injection as a control group. The maximal human adult dosage of carbamazepine (CBZ), valproate (VPA), and phenytoin (PHT) was administered as monotherapy to different groups of kindled rats for 1 month (n = 20 for each group). Changes in EEG recording, seizure number, intensity (expressed as grade 1,5 according to Racine stage), and duration, including spontaneous seizures during different interventions, were compared. The expression of P-170, a multiple drug resistance gene (MDR1) encoding P-glycoprotein, was measured in brain samples from different groups of experimental rats by using an image analysis and measurement system (ImagePro-Plus 4.0). Results: A total of 70 (46.7%) rats were fully kindled with a median of 15 (seven to 20) CL injections. Electrocorticogram (ECoG) including hippocampal (EHG) monitoring revealed the temporal lobe origins of epileptiform potentials, which were consistent with the behavioral changes observed. Spontaneous seizures occurred with frequency and diurnal patterns similar to those of human TLE. The antiepileptic drugs (AEDs) tested lacked a satisfactory seizure control. The maximal P-170 expression was in the kindled rats with AED treatment; the next highest was in the kindled rats without AED intervention. Nonkindled SD rats with CL injection also had increased P-170 expression compared with control SD rats. Conclusions: The study provided a simple and stable animal TLE kindling model with pharmacoresistant properties. The pharmacoresistance observed in the kindled rats to CBZ, VPA, and PHT at maximal human adult dosages together with the increased P-170 expression was a distinct feature of this model. This model might be used in further investigations of the mechanisms involved in pharmacoresistant TLE and for developing new AEDs. [source] Reentry in a Pulmonary Vein as a Possible Mechanism of Focal Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2004BERNARD BELHASSEN M.D. The case of an 18-year-old woman with recurrent idiopathic catecholamine-sensitive paroxysmal atrial fibrillation is reported. Recordings of multiple initiations of atrial fibrillation at the proximal part of the right superior pulmonary vein suggested local reentry in the vein as the mechanism of atrial fibrillation. A single radiofrequency pulse delivered at this site resulted in definite cure of the arrhythmia. (J Cardiovasc Electrophysiol, Vol. 15, pp. 824-828, July 2004) [source] Intestinal Dysbiosis: A Possible Mechanism of Alcohol-Induced Endotoxemia and Alcoholic Steatohepatitis in RatsALCOHOLISM, Issue 10 2009Ece Mutlu Background:, Clinical and animal data indicate that gut-derived endotoxin and other luminal bacterial products are necessary cofactors for development of alcoholic liver disease (ALD). Although gut leakiness is clearly an important cause of endotoxemia in ALD, it cannot fully explain endotoxemia in all ALD subjects and thus other factors may be involved. One possible factor is a change in gut microbiota composition (dysbiosis). Thus, the aim of our study was to interrogate the gut bacterial microbiota in alcohol-fed rats to see if chronic alcohol consumption affects gut bacteria composition. Method:, Male Sprague,Dawley rats were given either alcohol or dextrose intragastrically by gavage twice daily for up to 10 weeks. A subgroup of rats was also given either a probiotic (lactobacillus GG) or a prebiotic (oats) by gavage. Ileal and colonic mucosal-attached microbiota composition were interrogated by Length Heterogeneity PCR (LH-PCR) fingerprinting. Results:, Bacterial microbiota composition in alcohol-fed rats is not different from dextrose-fed rats at weeks 4 and 6. Mucosa-associated microbiota composition in the colon is altered at 10 weeks of daily alcohol gavage. Both LGG and oats prevented alcohol-induced dysbiosis up to 10 weeks of alcohol treatment. Conclusion:, Daily alcohol consumption for 10 weeks alters colonic mucosa-associated bacterial microbiota composition in rats. Our data showed, for the first time, that daily alcohol consumption can affect colonic microbiome composition and suggest that dysbiosis may be an important mechanism of alcohol-induced endotoxemia. Further studies are needed to determine how dysbiotic microbiota contributes to development of ALD and whether therapeutic interventions targeted towards dysbiotic microbiota can prevent complications of alcoholism like ALD. [source] Derangement of Heart Rate Variability During a Catastrophic Earthquake: A Possible Mechanism for Increased Heart AttacksPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2001LIAN-YU LIN LIN, L.-Y., et al.: Derangement of Heart Rate Variability During a Catastrophic Earthquake: A Possible Mechanism for Increased Heart Attacks. At 1:47 AM on September 21, 1999, the middle part of Taiwan was struck by a major earthquake measuring 7.3 on the Richter scale. It has been shown that the mental stress caused by an earthquake could lead to a short- or long-term increase in frequency of cardiac death probably through activation of the sympathetic nervous system. The aim of this study was to investigate the effects of emotional stress on the autonomic system during an actual earthquake. Fifteen patients receiving a 24-hour Holter ECG study starting from 10 ± 4 hours before the onset of the earthquake were included for the analysis of time- and frequency-domains of heart rate variability (HRV) at several time periods. A 24-hour Holter study recorded 2,6 months before the earthquake in 30 age- and sex-matched subjects served as the control group. Heart rate and the low frequency (LF) to high frequency (HF) ratio increased significantly after the earthquake and were attributed mainly to the withdrawal of the high frequency component (parasympathetic activity) of HRV. Sympathetic activation was blunted in elderly subjects > 60 years old. The concomitant ST-T depression observed in the Holter study correlated with a higher increment of LF as compared to HF components. The changes observed in HRV recovered completely 40 minutes following the earthquake. The derangement of HRV results from the withdrawal of the parasympathetic component and the arousal of sympathetic activity by the stressful earthquake. However, this autonomic derangement returned towards normal 40 minutes following the earthquake. [source] The Green Oat Story: Possible Mechanisms of Green Color Formation in Oat Products during CookingJOURNAL OF FOOD SCIENCE, Issue 6 2009D.C. Doehlert ABSTRACT:, Consumers occasionally report greenish colors generated in their oat products when cooking in tap water. Here we have investigated pH and ferrous (Fe2+) ion as possible mechanisms for this color change. Steel-cut oat groats can turn brown-green color when cooked in alkaline conditions (pHs 9 to 12). Extraction of this color with methanol, and high-pressure liquid chromatography indicated a direct association of this color with the phenolic acid or avenanthramide content of the oat. The presence of 50 mM NaHCO3 in water will cause oat/water mixtures to turn alkaline when cooked as CO2 is driven off, generating OH, ion. Although tap water rarely, if ever, contains so much bicarbonate, bicarbonate is used as a leavening agent in baking applications. Industrial interests using baking soda or alkaline conditions during oat processing should be aware of possible off color generation. We have also found that as little as 10 ppm Fe2+ will turn oat products gray-green when cooked. The aleurone stained darker than the starchy endosperm. Other divalent cations, such as Ca2+ or Mg2+ had no effect on cooked oat color. As much as 50 ppm Fe2+ may be found in freshly pumped well water, but Fe2+ reacts quickly with oxygen and precipitates as Fe(OH)3. Thus, some freshly pumped well water may turn oats green when cooked, but if the water is left under atmospheric conditions for several hours, no discoloration will appear in the cooked oats. [source] An Analysis of Possible Mechanisms of Unexpected Death Occurring in Hydatid Disease (Echinococcosis)JOURNAL OF FORENSIC SCIENCES, Issue 4 2009Roger W. Byard M.B.B.S. Abstract:, Most cases of hydatid disease in human populations are due to Echinococcus granulosus. The hydatid life cycle involves passage between definitive hosts such as dogs and intermediate hosts such as sheep. Humans become accidental intermediate hosts following ingestion of food or water contaminated with eggs or by contact with infected dogs. Although hydatid disease may remain asymptomatic, occasional cases of sudden and unexpected death present to autopsy. Causes of rapid clinical decline involve a wide range of mechanisms including anaphylaxis (with or without cyst rupture), cardiac outflow obstruction or conduction tract disturbance, pulmonary and cerebral embolism, pericarditis, cardiac tamponade, myocardial ischemia, pulmonary hypertension, peritonitis, hollow organ perforation, intracerebral mass effect, obstructive hydrocephalus, seizures, cerebral ischemia/infarction, and pregnancy complications. The autopsy assessment of cases therefore requires careful examination of all organ systems for characteristic cystic lesions, as multiorgan involvement is common, with integration of findings so that possible mechanisms of death can be determined. Measurement of serum tryptase and specific IgE levels should be undertaken for possible anaphylaxis. [source] 122 Local to Coastal-Scale Macrophyte Community Structure: Surprizing Patterns and Possible MechanismsJOURNAL OF PHYCOLOGY, Issue 2003B. A. Menge Understanding large-scale patterns in ecological communities is a central goal of ecology, and yet, rigorous quantitative geographic data on distribution, abundance and diversity are almost totally lacking. Even in rocky intertidal habitats, our data on community structure are spatially and temporally limited, with most surveys limited to a few sites over short time periods. When linked to studies of community dynamics on similar scales, such studies should provide insights into the determinants of pattern at more relevant scales. In 1999 PISCO, the Partnership for Interdisciplinary Studies of Coastal Oceans, initiated survey programs aimed at determining patterns of community structure along the US west coast from Washington to Baja California. Sites are regularly spaced along the coast in a nested design, and were physically similar. Surveys used randomly placed quadrats in transects run parallel to shore in high, mid and low zones. Results show that, contrary to expectation, macroalgal diversity along the northern coast was higher, not lower than that along the southern coast. Possible factors associated with this unexpected pattern include along-coast variation in tidal amplitude, time of tide, thermal stress, upwelling intensity and resulting nutrient gradients, disturbance from storms or sand burial, and grazing. We review evidence relevant to these factors, and focus on the possible role of grazing, using field experiments done under differing oceanographic conditions along the Oregon coast as a model. Although short-term grazing rates can vary with oceanographic condition, we hypothesize that despite these results and those of many similar studies showing strong grazing effects on local spatial and short time scales, that bottom-up factors are stronger determinants of macroalgal community structure on larger spatial scales and longer time scales. [source] Onium Salts of Amino Acids as Co-Initiators in Photoinduced Free-Radical PolymerizationMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2006Franciszek, cigalski Abstract Summary: The onium salts of selected aliphatic and aromatic amino acids were investigated as electron donors in photoinduced free radical polymerization, in conjunction with either DIBF or BP as sensitizer. The laser flash photolysis experiments unmistakably documented that the free radical formation occurs via an electron transfer reaction from the amino acid salt to the chromophore triplet state. The kinetic studies clearly showed that either the DIBF or BP onium salts of selected aliphatic and aromatic sulfur-containing amino acids exhibit a significant increase in the efficiency of free-radical polymerization of TMPTA as compared to non-sulfur-containing co-initiators and that the efficiency of all tested electron donors is only slightly dependent on the cation type coupled with co-initiators tested. Possible mechanism for the free radical photoinitiated polymerization. [source] Possible mechanism of dexamethasone therapy for prostate cancer: Suppression of circulating level of interleukin-6THE PROSTATE, Issue 2 2003Koichiro Akakura Abstract BACKGROUND Glucocorticoids may have favorable effects on prostate cancer patients showing clinical and/or biochemical failure after androgen ablation. The efficacy and mechanisms of dexamethasone therapy as possible alternative endocrine therapy were investigated. METHODS Twenty five patients with prostate cancer treated by androgen ablation and showing a steady increase in serum prostate specific antigen (PSA) were treated with low-dose dexamethasone. RESULTS Of 25 patients, 11 demonstrated 50% or more decline of serum PSA and 9 showed improvement of pain on dexamethasone therapy. Of 8 patients who responded to dexamethasone thearpy, 5 had 80% or more decrease in serum interleukin-6 (IL-6). In contrast, none of 8 non-responders showed remarkable IL-6 suppression. Response of PSA was not correlated to the changes in serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, or androstendione. CONCLUSIONS Significant suppression of serum IL-6, probably through inhibition of androgen-independent activation of androgen receptor, may be one of the mechanisms for the effect of dexamethasone therapy in prostate cancer patients with progressive disease. Prostate 56: 106,109, 2003. © 2003 Wiley-Liss, Inc. [source] Mechano-biology of skeletal muscle hypertrophy and regeneration: Possible mechanism of stretch-induced activation of resident myogenic stem cellsANIMAL SCIENCE JOURNAL, Issue 1 2010Ryuichi TATSUMI ABSTRACT In undamaged postnatal muscle fibers with normal contraction and relaxation activities, quiescent satellite cells of resident myogenic stem cells are interposed between the overlying external lamina and the sarcolemma of a subjacent mature muscle fiber. When muscle is injured, exercised, overused or mechanically stretched, these cells are activated to enter the cell proliferation cycle, divide, differentiate, and fuse with the adjacent muscle fiber, and are responsible for regeneration and work-induced hypertrophy of muscle fibers. Therefore, a mechanism must exist to translate mechanical changes in muscle tissue into chemical signals that can activate satellite cells. Recent studies of satellite cells or single muscle fibers in culture and in vivo demonstrated the essential role of hepatocyte growth factor (HGF) and nitric oxide (NO) radical in the activation pathway. These experiments have also reported that mechanically stretching satellite cells or living skeletal muscles triggers the activation by rapid release of HGF from its extracellular tethering and the subsequent presentation to the receptor c-met. HGF release has been shown to rely on calcium-calmodulin formation and NO radical production in satellite cells and/or muscle fibers in response to the mechanical perturbation, and depend on the subsequent up-regulation of matrix metalloproteinase (MMP) activity. These results indicate that the activation mechanism is a cascade of events including calcium ion influx, calcium-calmodulin formation, NO synthase activation, NO radical production, MMP activation, HGF release and binding to c-met. Better understanding of ,mechano-biology' on the satellite cell activation is essential for designing procedures that could enhance muscle growth and repair activities in meat-animal agriculture and also in neuromuscular disease and aging in humans. [source] Development of lymphatic vessels in mouse embryonic and early postnatal heartsDEVELOPMENTAL DYNAMICS, Issue 10 2008Juszy, Micha Abstract We aimed to study the spatiotemporal pattern of lymphatic system formation in the embryonic and early postnatal mouse hearts. The first sign of the development of lymphatics are Lyve-1,positive cells located on the subepicardial area. Strands of Lyve-1,positive cells occur first along the atrioventricular sulcus of the diaphragmatic surface and then along the great arteries. Lumenized tubules appear, arranged in rows or in a lattice. They are more conspicuous in dorsal atrioventricular junction, along the major venous and coronary artery branches and at the base of the aorta and the pulmonary trunk extending toward the heart apex. At later stages, some segments of the lymphatic vessels are partially surrounded by smooth muscle cells. Possible mechanisms of lymphangiogenesis are: addition of Lyve-1,positive cells to the existing tubules, elongation of the lymphatic lattice, sprouting and coalescence of tubules. We discuss the existence of various subpopulations of endothelial cells among the Lyve-1,positive cells. Developmental Dynamics 237:2973,2986, 2008. © 2008 Wiley-Liss, Inc. [source] Olfactory learning in the rat immediately after birth: Unique salience of first odorsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 6 2009Stacie S. Miller Abstract An infant rat's chance of survival is increased when it remains close to the nest. Early olfactory learning supports such adaptive behavior. Previous experiments indicated that non-associative odor exposure immediately after birth promoted later attachment to a similarly scented artificial nipple. The goal of the current experiments was to extend these findings on olfactory learning in the hours after birth by: exposing pups to more than one odor exposure (Experiment 1), dissecting the role of timing versus order of odor exposure (Experiment 2), testing the odor specificity of these effects (Experiments 3 and 4), and evaluating associative odor conditioning soon after birth (Experiment 5). Without explicit prior odor experience, pups only hours old do not respond much to a novel odor. Prior non-associative odor experience increases later motor activity to that same odor and to novel odors. Furthermore, these findings may be specific to certain amodal dimensions of the (in our case) lemon odor exposure. Single odor non-associative and associative conditioning was equally effective immediately after birth and during the third postnatal hour. Nevertheless, pups given two mere odor exposures responded to the first one more than the second at test, regardless of whether the exposures began immediately or 2,hr after birth. Possible mechanisms for these findings concerning early olfactory learning are discussed. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 488,504, 2009 [source] Possible mechanisms for the anticonvulsant activity of fructose-1,6-diphosphateEPILEPSIA, Issue 2008Janet L. Stringer Summary Fructose-1,6-diphosphate (FDP), an intracellular metabolite of glucose, has anticonvulsant activity in several models of acute seizures in laboratory animals. The anticonvulsant effect of FDP is most likely due to a direct effect since intraperitoneal and oral administration results in significant increases in brain levels. A number of mechanisms have been proposed for this action of FDP. One possibility is that peripheral administration of FDP results in changes in brain metabolism that are anticonvulsant. Glucose can be metabolized through the glycolytic or pentose phosphate pathway. There is evidence that the pentose phosphate pathway is more active in the brain than in other tissues, and that, in the presence of elevated levels of FDP, the majority of glucose is metabolized by the pentose phosphate pathway. The pentose phosphate pathway generates NADPH, which is used to reduce glutathione. The reduced form of endogenous glutathione has been shown to have anticonvulsant activity. Taken together, the data suggest a hypothesis that exogenously administered FDP gets into the brain and astrocytes where it increases the flux of glucose through the pentose phosphate pathway, generating additional NADPH for the reduction of glutathione. [source] Hydrosilanes Are Not Always Reducing Agents for Carbonyl Compounds, II: Ruthenium-Catalyzed Deprotection of tert -Butyl Groups in Carbamates, Carbonates, Esters, and EthersEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2010Shiori Hanada Abstract Hydrosilanes act as a reagent to cleave the C,O bond of OtBu groups in carbamates, carbonates, esters, and ethers by catalysis of a triruthenium cluster. The reaction offers a novel deprotection method for OtBu groups under neutral conditions, showing unique selectivities that have never been accomplished with conventional Brønsted or Lewis acidic promoters. Possible mechanisms for C,O cleavage are discussed on the basis of NMR spectroscopic analysis. [source] A Novel Direct Conversion of Primary Amides to Their Corresponding Methyl EstersEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2007Liang-Chun Li Abstract A novel method was used to directly convert aliphatic and aromatic primary amides into their corresponding methyl esters in high yields (up to 99,%) under mild reaction conditions. Possible mechanisms were studied at the B3LYP/6-31++G(d,p) level of theory. Formation of the ester proceeded through a rearrangement of the ,OMe and ,NH2 groups in the RC(O)NHS(O)OMe intermediate in a H+ -catalyzed six-membered ring transition state structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Copepod species diversity and climate variability in the tropical Atlantic OceanFISHERIES OCEANOGRAPHY, Issue 4-5 2003Sergey A. Piontkovski Abstract A database synthesized from 19 oceanographic expeditions conducted by the former Soviet Union was used to analyse interannual patterns in copepod species diversity in the tropical Atlantic. Mesozooplankton was collected predominately in vertical hauls through the upper 100 m with Juday nets. The samples from 744 oceanographic stations were identified and enumerated to the species level. To assess species diversity, the Shannon diversity index was used. On the interdecadal scale, no statistically confirmed trend was found in species diversity change over the years sampled (1963,89). Multiple regression analysis indicated that interannual fluctuations of the South Atlantic High (pressure and latitude), the Azores High longitude and El Niño,Southern Oscillation (ENSO) index could explain 87% of species diversity fluctuations. Possible mechanisms that drive interannual fluctuations of species diversity are discussed. [source] A novel gene, MDS2, is fused to ETV6/TEL in a t(1;12)(p36.1;p13) in a patient with myelodysplastic syndromeGENES, CHROMOSOMES AND CANCER, Issue 1 2002María D. Odero ETV6/TEL is the first transcription factor identified that is specifically required for hematopoiesis within the bone marrow. This gene has been found to have multiple fusion partners of which 16 have been cloned. Fluorescence in situ hybridization (FISH) analysis in a patient with myelodysplastic syndrome (MDS) revealed a t(1;12)(p36;p13) involving ETV6, with the breakpoint in this gene between exon 2 and exon 3. We report here the cloning of a novel ETV6 partner located on 1p36.1, involved in the t(1;12). 3, RACE-PCR from RNA identified a novel sequence fused to exon 2 of ETV6. Database searches localized this sequence in a bacterial artificial chromosome (BAC) mapped to 1p36 by fingerprint analysis. This result was confirmed by FISH using this BAC as probe. 5, and 3, RACE experiments with primers from this novel sequence were carried out on RNA from a healthy donor and identified a novel full-length mRNA, which we named MDS2 (myelodysplastic syndrome 2). RT-PCR experiments were performed on a panel of human cDNAs to analyze the expression pattern of this gene and they revealed four splicing variants. RT-PCR analysis showed that ETV6-MDS2, but not the reciprocal MDS2-ETV6 fusion transcript, was expressed in the bone marrow of the patient. The product of the ETV6-MDS2 fusion transcript predicts a short ETV6 protein containing the first 54 amino acids of ETV6 plus four novel amino acids, lacking both the PTN and the DNA-binding domains. Possible mechanisms to account for the development of MDS in this patient are discussed. © 2002 Wiley-Liss, Inc. [source] A comparison of infestation patterns by Ixodes ticks in urban and rural populations of the Common Blackbird Turdus merulaIBIS, Issue 4 2002Arnaud Gregoire Although spatial variation in the patterns of parasite infestations among host populations may have important ecological and epidemiological consequences, the causes underlying such variation are poorly known. In the context of a long-term study on the population biology of Common Blackbirds Turdus merula, we examined the prevalence and intensity of infestation by Ixodes ticks between birds living in rural vs. urban habitats. The overall prevalence of tick infestations was significantly higher in the rural habitat where 74% of individuals (n = 130) were infested. This result contrasted markedly with the situation in the urban habitat where less than 2% of individuals (n = 360) carried ticks. There was no significant effect of the sex of the host on the intensity or prevalence of tick infestations. There was a significant effect of the age of the host on tick infestations essentially due to the absence of ticks on nestlings. Possible mechanisms responsible for the differences between habitats could include differences in tick survival and/or host resistance towards ticks. Previous studies have shown higher population densities and suggested longer survival for Blackbirds in urban than in rural habitats. Given that ixodid ticks are known to transmit pathogens like Borrelia spp. to wild birds, and that Blackbirds can act as reservoirs for these pathogens, the infection patterns observed in our study area provide a suitable situation to study the interrelations between ticks, Blackbirds and pathogens. [source] Phosphodiesterase 5 inhibitors in the treatment of premature ejaculationINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2006W. F. Wang Summary To date, there is no FDA-approved therapy for premature ejaculation (PE). Recently, phosphodiesterase 5 inhibitors (PDE5 -Is) have been demonstrated to have encouraging results in the treatment of PE by a few studies. The aim of this review was to assess the updated manuscripts and thereafter present the practical recommendations and possible mechanisms concerning PDE5 -Is for treating PE. Using MEDLINE, we searched and assessed the peer manuscripts published from 1 January 1996 to 1 September 2005 about PDE5 -Is for treating PE. The results show that the number of patients in all the reports is very few and most of the studies do not employ double-blinded and placebo-controlled tests, though they are prospective and randomized. Therefore, the results and conclusions might be biased. PDE5 -Is are suggested to be used in PE with old age or associated with erectile dysfunction (ED), or to be employed alone or in combination with selective-serotonin reuptake inhibitors (SSRIs) when SSRIs fail to treat PE; behavioural therapy is proposed to be used for preventing the recurrence of PE following withdrawal of PDE5 -Is. In addition, for the PE patient with a definite aetiological cause, the aetiology should be cured first, if PE still exists, followed by PDE-Is prescription. Possible mechanisms that are involved include relaxing the smooth muscles of vas deferens, seminal vesicle, prostate and urethra; decreasing the central sympathetic output; inducing peripheral analgesia; prolonging the duration of erection; and increasing confidence, the perception of ejaculatory control, overall sexual satisfaction, and decreasing the post-orgasmic refractory time to achieve a second erection after ejaculation. Well-designed multicentre studies are urgently warranted to further elucidate the efficacies and safety as well as mechanisms of PDE5 -Is in the treatment of PE. [source] Zosteriform metastatic transitional cell carcinomaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2005Christy A. Woodruff MD Presentation of metastatic nodules in a dermatomal distribution is very rare. We present the case of a 63-year-old woman with zosteriform metastasis secondary to transitional cell carcinoma of the bladder. Possible mechanisms of dissemination are discussed. [source] Notalgia paresthetica: a study on pathogenesisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2000avk MD Background Notalgia paresthetica is a sensory neuropathy involving the dorsal spinal nerves. The characteristic symptom is pruritus on the back, occasionally accompanied by pain, paresthesia, and/or hyperesthesia, which results in a well-circumscribed hyperpigmented patch in the symptomatic area. The etiology of this condition has not yet been completely defined. Objective Possible mechanisms that could explain the pathogenesis of notalgia paresthetica were investigated through clinical examination and various diagnostic tests. Methods Ten cases of notalgia paresthetica underwent dermatologic, neurologic, and orthopedic examination. This was followed by skin biopsy, electrodiagnostic investigation, and radiography of the spine. Results All patients had a typical symptomatology and dermatologic picture. Neurologic examination and standard electrodiagnostic investigation results were normal in all cases. Histopathology was compatible with postinflammatory hyperpigmentation; there were no amyloid deposits. In seven cases, degenerative changes in the vertebrae were observed and, in all of these cases, these changes were most prominent in the vertebrae which corresponded to the dermatome of the cutaneous lesion. Conclusions The striking correlation of notalgia paresthetica localization with degenerative changes in the spine suggests that spinal nerve impingement may contribute to the pathogenesis of this entity. [source] Nurses' role in detecting deterioration in ward patients: systematic literature reviewJOURNAL OF ADVANCED NURSING, Issue 10 2009Mandy Odell Abstract Title.,Nurses' role in detecting deterioration in ward patients: systematic literature review. Aim., This paper is a report of a review conducted to identify and critically evaluate research investigating nursing practice in detecting and managing deteriorating general ward patients. Background., Failure to recognize or act on deterioration of general ward patients has resulted in the implementation of early warning scoring systems and critical care outreach teams. The evidence of effectiveness of these systems is unclear. Possible mechanisms for low effectiveness may be inconsistent recording of patient observations by ward staff, or inconsistent application of ,calling criteria' for outreach teams, even when observations have been recorded. Methods., The literature was searched between 1990 and 2007 using four sources: electronic databases, reference lists, key reports and experts in the field. Three broad search categories were used: nursing observations, physiological deterioration and general ward patients. All research designs describing nursing observations (vital signs) on deteriorating adult patients in general hospital wards were included. Results., Fourteen studies met the inclusion and quality criteria. The findings were grouped into four main themes: recognition; recording and reviewing; reporting; and responding and rescuing. The main findings suggest that intuition plays an important part in nurses' detection of deterioration, and vital signs are used to validate intuitive feelings. The process is highly complex and influenced by many factors, including the experience and education of bedside nurses and their relationship with medical staff. Conclusion., Greater understanding of the context within which deterioration is detected and reported will facilitate the design of more effective education and support systems. [source] Possible mechanisms for the relative efficacies of ortho -phthalaldehyde and glutaraldehyde against glutaraldehyde-resistant Mycobacterium chelonaeJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2001S.E. Walsh Aims: This investigation compared glutaraldehyde (GTA)-sensitive and -resistant strains of Mycobacterium chelonae and examined the effects of pretreatment of GTA-sensitive and -resistant strains of Myco. chelonae with chemical agents that interfere with cell wall synthesis. Methods and Results: When exposed to 2% (v/v) GTA at 25°C, GTA-resistant strains of Myco. chelonae dried on to glass carriers were not inactivated to any significant extent. By contrast, GTA-sensitive strains of Myco. chelonae and a strain of Myco. terrae suffered a > 6 log reduction in viability in 5 min. However, ortho -phthalaldehyde (OPA; 0·5% w/v) achieved a corresponding inactivation against two GTA-resistant strains within 5,10 and 10,20 min, respectively. Electron microscopy, using a non-aldehyde fixation process and also negative staining, failed to detect any extensive changes in GTA-sensitive and -resistant cultures exposed to GTA or OPA. Thin-layer chromatography was unsuccessful in detecting differences between GTA-resistant and -sensitive strains of Myco. chelonae. However, pretreatment of GTA-resistant cells with mycobacterial cell wall synthesis inhibitors increased their subsequent susceptibility further to OPA but not to GTA. Conclusions:Ortho -phthalaldehyde is an effective new biocidal agent that, at its in-use concentration, is rapidly bactericidal to non-sporulating bacteria, including GTA-sensitive and -resistant mycobacteria. Significance and Impact of the Study: Pretreatment of GTA-resistant cells with mycobacterial cell wall synthesis inhibitors increased their subsequent susceptibility to OPA but not to GTA. [source] Heart rate variability , a therapeutic target?JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2002H. C. Routledge Reduced heart rate variability (HRV) is a powerful and independent predictor of an adverse prognosis in patients with heart disease and in the general population. The HRV is largely determined by vagally mediated beat to beat variability, conventionally known as respiratory sinus arrhythmia. Thus, HRV is primarily an indicator of cardiac vagal control. It is still unclear whether the relationship between measures of cardiac vagal control and mortality is causative or mere association. Possible mechanisms by which cardiac vagal activity might beneficially influence prognosis include a decrease in myocardial oxygen demand, a reduction in sympathetic activity and a decreased susceptibility of the ventricular myocardium to lethal arrhythmia. In animals, augmentation of cardiac vagal control by nerve stimulation or by drugs is associated with a reduction in sudden death in susceptible models. In humans a number of drugs which have been shown to reduce mortality and sudden death in large randomised trials can also be demonstrated to increase HRV. As a result of this evidence, it has been suggested that the effect of drugs or other therapeutic manoeuvres on HRV might be used to predict clinical efficacy. The use of HRV as a therapeutic target is discussed in this review. [source] Interpersonal psychotherapy for borderline personality disorder: Possible mechanisms of changeJOURNAL OF CLINICAL PSYCHOLOGY, Issue 4 2006John C. Markowitz This article describes the rationale for applying interpersonal psychotherapy (IPT) to the treatment of patients who have borderline personality disorder and explains the adaptation of standard IPT to that end. The authors describe the preliminary stages of adapting IPT for a pilot study to test its feasibility and potential efficacy and speculate on potentially therapeutic mechanisms for IPT in treating patients who have borderline personality disorder. © 2006 Wiley Periodicals, Inc. J Clin Psychol 62: 431,444, 2006. [source] Feigning death in the Central American cichlid Parachromis friedrichsthaliiJOURNAL OF FISH BIOLOGY, Issue 3 2005M. Tobler Feigning death, a hunting strategy in which a healthy individual acts as if it was dead to trick prey into its reach, is reported for a population of the Central American cichlid Parachromis friedrichsthalii. Possible mechanisms leading to the evolution of such a behaviour are discussed. [source] Hormone replacement therapy and cardiovascular disease: increased risks of venous thromboembolism and stroke, and no protection from coronary heart diseaseJOURNAL OF INTERNAL MEDICINE, Issue 5 2004G. D. O. Lowe Abstract. Hormone replacement therapy (HRT) was increasingly promoted over the last 40 years to improve quality of life, and to reduce the risks of osteoporotic fractures and coronary heart disease (CHD). In recent years, observational studies, randomized trials and systematic reviews of such trials have shown that HRT does not reduce, but actually increases cardiovascular risk. HRT increases the relative risks of venous thromboembolism (twofold), and of fatal or disabling stroke (by 50%); whilst increasing the early risk of myocardial infarction and having no protective effect against CHD on longer term use. Possible mechanisms for these increased cardiovascular risks include down-regulation of several inhibitory pathways of blood coagulation, resulting in increased coagulation activation, which promotes venous and arterial thrombosis. The implications for prescription are discussed, as are lessons for future evaluation of health care interventions. [source] Vertebrate limb development and possible clues to diversity in limb formJOURNAL OF MORPHOLOGY, Issue 1 2002Cheryll Tickle Abstract Chick embryos are good models for vertebrate development. The principles that underlie chick wing development have been discovered and there is increasing knowledge about the molecules involved. The importance of identifying molecules is that this provides a direct link to understanding the genetic basis of diversity in form. Chick wing development will be compared with limb development in other vertebrates. Possible mechanisms that could lead to variations in form, including limb reductions and limblessness, differences between fore- and hindlimbs, limb proportions, and interdigital webbing can be suggested. J. Morphol. 252:29,37, 2002. © 2002 Wiley-Liss, Inc. [source] Recognition and management of critical illness by midwives: implications for service provisionJOURNAL OF NURSING MANAGEMENT, Issue 3 2007ENB 100, PGDipHE, SUZANNE BENCH RGN Aim, The aim of this study was to explore midwives' recognition and management of critical illness in obstetric women in order to inform service provision. Background, Critical illness is not confined to Intensive Care. Limited published work was located examining factors affecting critical care provision by midwives. Methods, A multi-method design incorporating a paper and pencil simulation (n = 11) and in-depth interviewing (n = 5) was conducted with midwives from a large London National Health Service Trust. This study details and discusses the findings. Results, Findings indicated that frequency and type of critical illness experience impact upon midwives' critical care knowledge and skills. Midwives, especially those who were more junior, expressed anxiety regarding this aspect of practice, and considered the support of senior midwives, medical and nursing staff as crucial to effective client management. Conclusion, This study has yielded important insights into midwives' management of critical illness. Possible mechanisms to enhance the quality of service provision, and midwife support in this area are highlighted. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||