High Doses (high + dose)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of High Doses

  • single high dose
  • very high dose

  • Terms modified by High Doses

  • high dose chemotherapy

  • Selected Abstracts


    ORIGINAL ARTICLE: A High Dose of Intravenous Immunoglobulin Increases CD94 Expression on Natural Killer Cells in Women with Recurrent Spontaneous Abortion

    AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2009
    Shigeki Shimada
    Problem, A high dose of intravenous immunoglobulin (HIVIg) therapy is effective in various diseases such as autoimmune diseases, and also is expected to have efficacy in recurrent spontaneous abortion (RSA). The aim of this study was to understand immunological mechanisms of this therapy. Method of study, By flowcytometric analyses, we examined phenotypic changes of a variety of immunological cells including natural killer (NK) cells, cytotoxic T cells, regulatory T cells and macrophages in peripheral blood of RSA women with HIVIg therapy (n = 8). Results, Expression percentages of inhibitory CD94 on NK cells significantly (P = 0.01) increased after the therapy (58.8 ± 21.4% versus 71.0 ± 17.6%). Conclusion, Mechanisms of possible efficacy of HIVIg therapy for RSA may include enhancement of CD94 expression and subsequent suppression of NK cell cytotoxicity. [source]


    Tolerability of High Doses of Lercanidipine versus High Doses of Other Dihydropyridines in Daily Clinical Practice: The TOLERANCE Study

    CARDIOVASCULAR THERAPEUTICS, Issue 1 2008
    Vivencio Barrios
    The TOLERANCE study was aimed to compare the tolerability of high doses of lercanidipine (20 mg) with that of other frequently used dihydropyridines (amlodipine 10 mg/nifedipine GITS 60 mg) in the treatment of essential hypertension in daily clinical practice. It was an observational, transversal, multicentre study performed in a Primary Care Setting. A total of 650 evaluable patients with essential hypertension and age , 18 years were included. They had been treated with high doses of lercanidipine (n= 446) or amlodipine/nifedipine GITS (n= 204) during at least 1 month and previously with low doses (10 mg, 5 mg, and 30 mg, respectively) of the same drugs. The main objective was to compare the rates of vasodilation-related adverse events between both groups. Rates of signs and symptoms related to vasodilation were significantly higher (P < 0.001) in the amlodipine/nifedipine GITS group (76.8%, CI 95%[70.7; 82.9]) than in lercanidipine group (60.8%, [56.1;65.5]). Blood pressure control (< 140/90 mmHg or <130/80 for diabetics) and type of concomitant antihypertensive medications were similar in both groups. Treatment compliance was good (around 93%) and fairly comparable in both groups. Most adverse events with lercanidipine were mild (74.5% vs. 64% in amlodipine/nifedipine GITS group, P= 0.035) whereas severe adverse event rates did not differ significantly between groups (2.8% vs. 3.6%). In conclusion, treatment with lercanidipine at high doses is associated with a lower rate of adverse events related to vasodilation compared to high doses of amlodipine or nifedipine GITS in clinical practice. [source]


    Thalidomide for Crohn's disease: High dose, low dose, or "no doze" at all?

    INFLAMMATORY BOWEL DISEASES, Issue 2 2000
    Jeffry A. Katz M.D.
    No abstract is available for this article. [source]


    High dose methotrexate population pharmacokinetics and Bayesian estimation in patients with lymphoid malignancy

    BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 8 2009
    Ye Min
    Abstract The purpose of present study was to develop a population pharmacokinetic model of high dose methotrexate (HD-MTX) infusion in patients with lymphoid malignancy, to investigate the biological and clinical covariates related to the drug distribution and elimination. It is also the purpose to propose a limited sampling strategy (LSS) for the estimation of the time above the threshold (0.2,µmol·L,1). A total 82 patients with lymphoid malignancy were involved in the study. A pharmacokinetic model was developed using nonlinear mixed-effect model. The influence of demographic characteristics, biological factors, and concurrent administration were investigated. The final predictive performance was validated by bootstrap and cross-validation. Bayesian estimation was evaluated. The pharmacokinetics of HD-MTX was described by a two-compartment model. The pharmacokinetic parameters and the inter-individual variability were as follows: the clearance CL, 7.45,L·h,1 (inter-individual variability 50.6%), the volume of the central and peripheral compartment V1, 25.9,L (22.5%), V2, 9.23,L (97.8%), respectively, and the intercompartmental clearance Q, 0.333,L·h,1 (70.4%). The influence of serum creatinine on CL and weight on V1 was retained in the final model. The protocol involved one sampling time at 44,h after the start of the infusion, allowing one to predict the time at which the MTX concentration reached the expected threshold (0.2,µmol·L,1). Serum creatinine and weight showed significant influence on methotrexate CL and V1, respectively. Furthermore, a Bayesian estimation based on the covariates and 44,h sample was developed, allowing prediction of the individual methotrexate pharmacokinetic parameters and the time to 0.2,µmol·L,1. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    The effects of heparin and related molecules on vascular permeability and neutrophil accumulation in rabbit skin

    BRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2002
    Helen Jones
    Unfractionated heparin (UH) has been shown to possess a wide range of properties which are potentially anti-inflammatory. Many of these studies, including effects of heparin on adhesion of inflammatory cells to endothelium, have been carried out in vitro. In the present study, we have used radioisotopic techniques to study the effect of UH, and related molecules, on in vivo inflammatory responses (plasma exudation (PE) and PMN accumulation) in rabbit skin induced by cationic proteins, mediators and antigen. Intradermal (i.d.) pretreatment with UH dose-dependently inhibited poly-L-lysine (PLL)-induced responses. The same treatment had no effect on antigen (extract of Alternaria tenuis, AT)-, formyl-methionyl-leucyl-phenylalanine (fMLP)- or leukotriene (LT) B4 -induced responses, although i.d. dextran sulphate (DS) significantly inhibited responses to all of these mediators. High dose (10,000 u kg,1) intravenous UH significantly decreased cutaneous responses to fMLP and LTB4. By comparison, the selectin inhibitor, fucoidin, and DS, were very effective inhibitors of these responses, and of responses to AT and PLL. In contrast to the weak effect in the in vivo studies, UH significantly inhibited in vitro homotypic aggregation of rabbit PMNs, showing that it can modify PMN function. Our data with i.d. UH confirm the important ability of this molecule to interact with and neutralize polycationic peptides in vivo, suggesting that this is a prime role of endogenous heparin. The lack of effect of exogenous heparin on acute inflammatory responses induced by allergen, suggests that cationic proteins are unlikely to be primary mediators of the allergen-induced PE or PMN accumulation. British Journal of Pharmacology (2002) 135, 469,479; doi:10.1038/sj.bjp.0704505 [source]


    Uridine adenosine tetraphosphate affects contractility of mouse aorta and decreases blood pressure in conscious rats and mice

    ACTA PHYSIOLOGICA, Issue 2 2010
    P. B. Hansen
    Abstract Aim:, In the anaesthetized rat, uridine adenosine tetraphosphate (Up4A) is a circulating, endothelium-derived vasoconstrictor presumably operating as such in un-anaesthetized animals. The present study investigated the in vivo effects of Up4A in conscious mice and rats, and its direct vascular effects in the mouse aorta in vitro. Methods:,In vivo, Up4A was given as step-up infusion at rates of 8,512 nmol min,1 kg,1 for 30 min periods in chronically catheterized rodents. In vitro, the effect of Up4A on rings of mouse aortae mounted in a myograph was tested. Results:, High doses of Up4A (mice: 512 nmol min,1 kg,1; rats: 128 nmol min,1 kg,1) caused hypotension (99 ± 4 to 64 ± 7 mmHg and 114 ± 3 to 108 ± 3 mmHg, respectively, both P < 0.01). In rats, Up4A significantly decreased sodium excretion by >75% and potassium excretion by ,60% without significant changes in urine flow. Exposure of phenylephrine-contracted rings to increasing concentrations of Up4A elicited contraction at 10,7 and 10,6 mol L,1 (18 ± 2% and 76 ± 16% respectively); unexpectedly, 10,5 mol L,1 caused a biphasic response with a contraction (19 ± 6%) followed by a relaxation (,46 ± 6%). No relaxation was observed when the concentration was increased further. Bolus exposure to 10,5 mol L,1 of Up4A caused contraction (+80 ± 2%). Added successively to untreated vessels, increasing concentrations of Up4A (10,7,10,5 mol L,1) induced a biphasic response of contraction followed by relaxation. Conclusion:, Up4A has direct biphasic effects on vascular smooth muscle of the mouse aorta but vasoconstriction dominates at low concentrations. In conscious rodents, step-up infusions of Up4A elicit hypotension and electrolyte retention. [source]


    Therapeutic aspects of growth hormone and insulin-like growth factor-I treatment on visceral fat and insulin sensitivity in adults

    DIABETES OBESITY & METABOLISM, Issue 1 2007
    K. C. J. Yuen
    Growth hormone (GH) is generally considered to exert anti-insulin actions, whereas insulin-like growth factor I (IGF-I) has insulin-like properties. Paradoxically, GH deficient adults and those with acromegaly are both predisposed to insulin resistance, but one cannot extrapolate from these pathological conditions to determine the normal metabolic roles of GH and IGF-I on glucose homeostasis. High doses of GH treatment have major effects on lipolysis, which plays a crucial role in promoting its anti-insulin effects, whereas IGF-I acts as an insulin sensitizer that does not exert any direct effect on lipolysis or lipogenesis. Under physiological conditions, the insulin-sensitizing effect of IGF-I is only evident after feeding when the bioavailability of circulating IGF-I is increased. In contrast, many studies in GH deficient adults have consistently shown that GH replacement improves the body composition profile although these studies differ considerably in terms of age, the presence or absence of multiple pituitary hormone deficiency, and whether GH deficiency was childhood or adult-onset. However, the improvement in body composition does not necessarily translate into improvements in insulin sensitivity presumably due to the anti-insulin effects of high doses of GH therapy. More recently, we have found that a very low dose GH therapy (0.1 mg/day) improved insulin sensitivity without affecting body composition in GH-deficient adults and in subjects with metabolic syndrome, and we postulate that these effects are mediated by its ability to increase free ,bioavailable' IGF-I without the induction of lipolysis. These results raise the possibility that this low GH dose may play a role in preventing the decline of ,-cell function and the development of type 2 diabetes in these "high risk" subjects. [source]


    Effects of age and viral determinants on chronicity as an outcome of experimental woodchuck hepatitis virus infection

    HEPATOLOGY, Issue 1 2000
    Paul J. Cote Ph.D.
    Acute hepadnavirus infections either resolve or progress to chronicity. Factors that influence chronicity as an outcome of hepatitis B virus (HBV) infection in humans can be studied experimentally in the woodchuck model. Accordingly, several woodchuck hepatitis virus (WHV) inocula were characterized. Representative inocula had high titers of infectious virus (approximately 107.7 -109.5 woodchuck 50% infectious doses per milliliter [WID50% /mL] by subcutaneous inoculation), with 1 WID50% ranging between 21 and 357 physical virion particles. WHV7P1 (standard high dose, 5 × 106WID50%) produced a 72% chronicity rate (i.e., percent chronic of total infected) in neonatal woodchucks (1-3 days old). Comparable doses of WHV8P1 resulted in a lower chronicity rate in neonates (34% chronic) indicating that it represented a strain different from WHV7P1. Neonatal woodchucks were more susceptible to chronic infection by high doses of WHV7P1 (range, 65%-75% chronic) compared with 8-week-old weanlings (33% chronic) and adult woodchucks (0% chronic; i.e., all resolved). High doses of cloned wild-type viruses also induced high rates of chronicity in neonates (70%-80% chronic). Chronicity rates in neonates were decreased for low doses of WHV7P1 (500 WID50% , 9% chronic) and for high doses of a precore WHeAg-minus mutant WHV8 clone (17% chronic). Thus, both age and viral determinants can influence chronicity as an outcome of experimental WHV infection. Standardized inocula will enable the study of mechanisms that initiate and maintain chronic hepadnavirus infection and also provide a means for developing WHV carriers for therapeutic studies. [source]


    Mesalazine 4 g daily given as prolonged-release granules twice daily and four times daily is at least as effective as prolonged-release tablets four times daily in patients with ulcerative colitis

    INFLAMMATORY BOWEL DISEASES, Issue 3 2001
    Dr. Per G. Farup
    Abstract Background High doses of mesalazine usually result in an inconvenient dosage schedule and reduced compliance. The goal of this trial was to compare the effects of mesalazine 4 g daily given as prolonged-release granules in packets of 1 g with that of prolonged-release tablets of 0.5 g. Methods Two hundred twenty-seven patients with mild-to-moderate ulcerative colitis were randomized to treatment with two packets twice daily (Gr-b.i.d.), 1 packet four times daily (Gr-q.i.d.) or 2 tablets four times daily (Ta-q.i.d.) for 8 weeks. A disease activity index (ulcerative colitis disease activity index; UC-DAI) was calculated, and the granules were defined as noninferior to the tablets if the lower limit of the 95% CI for the differences was more than ,1 UC-DAI score unit. Results Noninferiority of the granules compared with the tablets was demonstrated. The mean improvement in the UC-DAI in the treatment groups Gr-b.i.d., Gr-q.i.d., and Ta-q.i.d. were 3.2, 2.9, and 2.4, respectively; the proportion of complete responders in the three groups 39%, 37%, and 31%, respectively. There were no differences in side effects. Conclusion Mesalazine 4 g daily given as prolonged-release granules twice and four times daily is at least as effective as prolonged-release tablets four times daily in patients with mild to moderate ulcerative colitis. The patients preferred the twice daily dosing. [source]


    The Effect of NaF In Vitro on the Mechanical and Material Properties of Trabecular and Cortical Bone

    ADVANCED MATERIALS, Issue 4 2009
    Philipp J. Thurner
    High doses of sodium fluoride in bones lead to severe softening, by weakening interfacial properties between the inorganic minerals and the organic components, while leaving mineralization unchanged. This leads to reduction of microdamage and associated stress-whitening pointing to a change in failure mode. Accordingly, elastic modulus, failure stress, and indentation-distance increase are decreased, whereas failure strain is increased. [source]


    Effects of Low-Dose Prednisone on Bone Metabolism,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2005
    Francine N Ton MD
    Abstract Prednisone 5 mg/day suppresses multiple indices of bone formation in a randomized placebo-controlled trial in healthy postmenopausal females. This suggests that even low doses of prednisone may reduce bone repair or renewal and may have adverse effects on bone mass and/or bone strength. Introduction: High doses of chronic glucocorticoids are known to have adverse effects on bone, and measures to prevent bone loss are well established for doses >7.5 mg daily, because these doses can cause premature or exaggerated osteoporosis. However, it is unclear if chronic prednisone doses of 5 mg daily have the same effects on bone. There are no established recommendations for preventing glucocorticoid-induced osteoporosis in people taking prednisone 5 mg daily, a dose used frequently in medical practice to treat diseases of the lungs, joints, skin, muscles, eyes, nerves, etc. Our primary objective was to test whether prednisone 5 mg daily affects serum and urine indices of bone metabolism in healthy postmenopausal women. Our secondary objectives were to determine if prednisone 5 mg affected systolic or diastolic blood pressure or causes side effects. Materials and Methods: A double-blinded randomized placebo-controlled 8-week trial in 50 healthy postmenopausal women was conducted at the Massachusetts General Hospital Outpatient General Clinical Research Center. Patients were randomly assigned to prednisone 5 mg daily or matching placebo for 6 weeks, followed by a 2-week recovery phase. Markers of bone formation and resorption were determined at weeks 0, 2, 4, 6, and 8. Indices of osteoblast activity included serum propeptide of type I N-terminal procollagen (PINP), propeptide of type I C-terminal procollagen (PICP), osteocalcin, and bone-specific alkaline phosphatase (BSALP). Indices of osteoclast activity included urine and serum type I collagen N-telopeptide (NTX) and free urinary deoxypyridinoline (DPD). Results and Conclusions: Prednisone rapidly and significantly decreased serum PINP (p < 0.01), PICP (p < 0.01), and osteocalcin (p < 0.01) and free urinary deoxypyridinoline (p = 0.017). These changes were largely reversed during the recovery period. Side effects were indistinguishable in the two groups. Neither systolic nor diastolic blood pressure changed significantly throughout the study between the two groups. In conclusion, low-dose prednisone significantly decreases indices of bone formation and may decrease indices of bone resorption in postmenopausal women. Further studies are needed to assess the effects of low-dose prednisone on BMD and fracture risk. [source]


    Medicinal plants in Suriname: hypotensive effect of Gossypium barbadense

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2004
    J. A. Hasrat
    ABSTRACT In traditional medicine Gossypium barbadense L. is used against hypertension. Looking for a scientific basis for this use, the blood-pressure-lowering effect of the decoction of the leaves was confirmed. Fraction II (frII) of the crude extract of G. barbadense showed a dose-dependent hypotensive effect in anaesthetized rats. In hexamethonium-treated rats, the blood-pressure-lowering effect of frII was almost abolished. A small decrease of the blood-pressure-lowering effect was followed by an increase in the blood pressure. Phentolamine antagonized the increase in blood pressure in hexamethoniumtreated rats. High doses of atropine (4 mg/rat) suppressed both depressor and heart effects. In-vitro experiments revealed that atropine did not antagonize the contraction of the ileum of the rat. Tripelennamine in a concentration of 100 ,g could not influence the contraction either, whereas 300 ,g did. In the guinea-pig ileum 10 ,g tripelennamine did not reduce the contraction significantly. In the mechanism of action of frII, acetylcholine receptors could be involved, but not histaminergic or adrenergic receptors. Although it is still not known which compound(s) in G. barbadense is (are) the active substance(s), the results obtained may explain the use of this plant in traditional medicine in Suriname. [source]


    Effects of some synthetic kynurenines on brain amino acids and nitric oxide after pentylenetetrazole administration to rats

    JOURNAL OF PINEAL RESEARCH, Issue 4 2004
    Leila Bikjdaouene
    Abstract:, We have previously proven that some synthetic kynurenines behave as antagonists of the N-methyl- d -aspartate receptor inhibiting neuronal subtype of nitric oxide synthase activity. We now investigate the anticonvulsant activity of four of these kynurenines in pentylenetetrazole (PTZ)-treated rats. The rats were treated with each kynurenine (10,160 mg/kg, s.c.) 30 min before PTZ administration (100 mg/kg, s.c.). Then, latency, duration and intensity of the first seizure and the percent animal survival were noted. PTZ-induced death was counteracted by high doses of kynurenines. Latency of the first seizure was significantly increased and its intensity reduced at the same doses, whereas the duration of the first seizure significantly decreased with doses of 20 mg/kg in most of the kynurenines tested. Three hours after PTZ administration, the surviving animals were sacrificed and the levels of brain amino acids and nitrite were measured. PTZ administration increased glutamate, glutamine, serine and taurine levels in different brain areas. High doses of kynurenines generally counteracted the effects of PTZ on excitatory amino acids, but they also reduced inhibitory aminoacids. However, the most consistent effect of kynurenines was the dose-dependent reduction of brain nitrite levels induced by PTZ. These results reveal a new family of anticonvulsant drugs that affect mainly to nitric oxide production in the brain. [source]


    The pattern of use of non-steroidal anti-inflammatory drugs (NSAIDs) from 1997 to 2005: a nationwide study on 4.6 million people,,

    PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 8 2008
    Emil Loldrup Fosbøl
    Abstract Purpose To describe the nationwide pattern of use of non-steroidal anti-inflammatory drugs (NSAIDs) in the Danish population. Methods All Danish citizens aged 10 or above 1 January 1997 were included in the study. The national prescription registry was used to identify all claimed prescriptions for NSAIDs by the cohort until 2005. By individual-level-linkage of nationwide registries, information was acquired concerning hospitalizations, comorbidity, concomitant pharmacotherapy and socioeconomic factors. Results The population consisted of 4,614,807 individuals, of which 2,663,706 (57.8%) claimed at least one prescription for NSAID from 1997 to 2005. Ibuprofen and diclofenac were the most frequently used non-selective NSAIDs, whereas rofecoxib and celecoxib were the most frequently used selective cyclooxygenase-2 (COX-2) inhibitors. The usage was similar across all age groups. Female sex and increasing age was associated with increased use of NSAID. Factors predicting extensive NSAID use were: rheumatic disease (odds ratio (OR),=,1.79, 95% confidence interval (CI): 1.69,1.90), gout agents (allopurinol) (OR,=,2.54, CI: 2.44,2.64) and other pain medication (OR,=,3.27, CI: 3.23,3.31). NSAIDs were most often prescribed for use for one distinct treatment interval and for a short period (overall inter-quartile range [IQR]: 9,66 days). High doses were used in a relatively large proportion of the population (8.9% for etodolac to 19.5% for celecoxib) and 54,373 (2.0%) claimed prescriptions for more than one NSAID at the same time. Conclusion NSAIDs were commonly used in the Danish population. Since NSAIDs have been associated with increased cardiovascular risk, further research on the overall risk associated with these drugs on a national scale is needed. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Latest news and product developments

    PRESCRIBER, Issue 7 2007
    Article first published online: 11 JUL 200
    Poor asthma control with off-licence prescribing Children who are prescribed off-licence medications are more likely to have poor asthma control, according to an analysis from Dundee (Br J Gen Practice 2007;57:220-2). The review of 17 163 consultations identified 1050 (6.1 per cent) who received a prescription for an unlicensed use (defined as not licensed for children or the particular age group, or dose not licensed). High doses (4.5 per cent) were more frequent than unlicensed indications (1.9 per cent). Children who received off-label prescriptions reported statistically significantly more symptoms in the day or night, symptoms during activity, and increased use of daily short-acting beta2-agonists. The authors note that off-label prescribing appears to be increasing. Atkins diet most effective over one year? The ultra low-carbohydrate, high-protein Atkins diet achieved greater weight loss than other popular diets in overweight women over one year, say US investigators (J Am Med Assoc 2007;297:969-77). The study compared the Atkins diet with three diets designed as low- or very high-carbohydrate, or based on USA nutritional guidance, in 311 women with body mass index 27-40. After one year, mean weight loss was 4.7kg with the Atkins diet , significantly greater than with the low- carbohydrate diet (1.6kg) but not compared with very high-carbohydrate (2.2kg) or the nutrition-based diet (2.6kg). Metabolic endpoints were comparable or more favourable in women using the Atkins diet. Androgen therapy linked to gum disease The majority of men treated with androgen deprivation therapy for prostate cancer are more likely to have periodontal disease (J Urol 2007;177:921-4). After controlling for risk factors, the prevalence of periodontal disease was 80.5 per cent among treated men compared with 3.7 per cent in matched controls not receiving treatment. There was no difference in bone mineral density between the groups but plaque scores were significantly higher among treated men. Food Commission rebuts MHRA on additives An independent watchdog has not accepted the MHRA's justification for including certain additives in medicines for children. The Food Commission (www.foodcomm.org.uk) found that most medicines for children contained additives, some of which , including azo dyes and benzoates , are not permitted in food. The Commission called on the pharmaceutical industry to stop using ,questionable additives'. The MHRA stated that the licensing process takes into account the likely exposure to excipients that are considered essential to make medicines palatable to children. Colouring helps children to identify the correct medicine, and preservatives ensure a reasonable shelf-life. A list of additives is included in the product's summary of product characteristics and patient information leaflet. In response, the Commission states: , , it is quite possible to flavour medicines with natural oils or extracts, and natural colourings such as beetroot and beta-carotene can be used instead of azo dyes. If parents were advised to give these medicinal products at mealtimes the manufacturers could also add a little sugar to sweeten their products, rather than relying on artificial sweeteners.' All triptans the same? There is no economic case for choosing one triptan over another and no evidence for preferring a particular triptan for adults, a systematic review has concluded. The Canadian Agency for Drugs and Technologies in Health (www.cadth.ca) found that published trials had compared most triptans with sumatriptan but not with one another, and most economic evaluations were flawed. New drug for HIV Janssen-Cilag has introduced darunavir (Prezista), a new protease inhibitor for the treatment of HIV infection. Licensed for highly pre- treated patients in whom more than one other pro- tease inhibitor regimen has failed, darunavir must be co-administered with ritonavir (Norvir). A month's treatment at the recommended dose of 600mg twice daily costs £446.70. Variation in liquid captopril for children The NHS uses a wide range of liquid formulations of captopril to treat children with heart failure , with no assurance of their bioequivalence (Arch Dis Child 2007; published online 15 March. doi: 10.1136/adc.2006.109389). Specialists in Leicester surveyed 13 tertiary paediatric cardiac centres and 13 hospitals that referred patients to them. Only three tertiary centres supplied the same liquid for-mulation of captopril as their referring hospitals. Four hospitals supplied tablets for crushing and dissolving in water; the other hospitals and centres used a total of nine different formulations. The authors say the formulations had widely varying shelf-lives, determined empirically in all but one case, and were used interchangeably despite a lack of quality control data to establish their bioequivalence. QOF CVD targets not good enough for GPs Two-thirds of GPs want Quality Outcome Framework (QOF) targets for cardiovascular disease brought into line with those of the Joint British Societies latest guidance (JBS2), according to a survey by doctor.net.uk. The survey of 1000 GPs showed that 88 per cent were aware of the JBS2 guidelines and most were already implementing the targets for lipids, blood pressure and blood glucose in some form; however, only 55 per cent were implementing the JBS2 obesity target and 14 per cent were implementing screening for the over-40s. The JBS2 target for lipids in at-risk patients is <4mmol per litre total cholesterol and <2 mmol per litre LDL-cholesterol, compared with <5 and <3mmol per litre respectively in QOF and the NSF. The survey was commissioned by Merck Sharp & Dohme and Schering- Plough. Fracture warning Following warnings in the US that rosiglitazone (Avandia) is associated with an increased risk of fractures in women, Takeda has advised prescribers that pioglitazone (Actos) carries a similar risk. An analysis of the company's clinical trials database has revealed an excess risk of fractures of bones below the elbow and knee. The incidence was similar to the excess risk associated with rosiglitazone and also confined to women. Scottish approvals The Scottish Medicines Consortium (www.scottish medicines.org.uk) has approved for use within NHS Scotland the sublingual tablet formulation buprenorphine/naloxone (Suboxone) for the treatment of opioid dependence. It has also approved the combined formulation of valsartan and amlodipine (Exforge) and the restricted use of the If inhibitor ivabradine (Procoralan). [source]


    Oral thyroxine administration mimics photoperiodically induced gonadal growth in Japanese quail

    ANIMAL SCIENCE JOURNAL, Issue 5 2004
    Shinobu YASUO
    ABSTRACT Most temperate-zone animals are seasonal breeders. In a previous study, it was found that light-induced hormone conversion of thyroxine (T4) prohormone to active 3,5,3,-triiodothyronine (T3) in the mediobasal hypothalamus regulates photoperiodic response of gonads in Japanese quail. Here the effect of T4 or T3, administered in drinking water, on testicular growth in the Japanese quail kept under short days is shown. Testicular length was significantly increased in birds given T4 at doses of 4, 8 and 10 mg/L, while any dose of T3 had little effect on testicular growth. High doses (8 and 10 mg/L) of T4 and T3 resulted in high mortality and/or reduction of bodyweight. Among all of the treatment, 4 mg/L of T4 was the most effective on photoperiodic testicular growth, which caused little reduction in bodyweight. These data provide a new conventional method for promoting gonadal growth under short days. [source]


    Effects of a Vitamin E-Modified Dialysis Membrane and Vitamin C Infusion on Oxidative Stress in Hemodialysis Patients

    ARTIFICIAL ORGANS, Issue 6 2001
    Jaromír Eiselt
    Abstract: Hemodialysis deteriorates oxidative stress. Vitamin E is an antioxidant whose regeneration is provided for by vitamin C. The authors tested the effects of a vitamin E-modified membrane (E), nonmodified cellulose membrane (O), and vitamin C infusion (500 mg, C) into the arterial blood line during dialysis on parameters of oxidative stress. In a short-term study, 24 patients were subjected to a single dialysis session with E, O, E with C, and O with C protocols. In a long-term study (12 weeks), 20 patients were randomized into groups with C and without C on each dialysis, and both groups had dialysis using O, E, and again O membrane for 4 weeks each. In the short-term study, thiobarbituric acid reacting substances (TBARS) in plasma rose after dialysis (p < 0.02) with O, and no changes were observed in the other 3 protocols. In the long-term study, predialysis TBARS declined when using E both in the groups with C (p < 0.02) and without C (p < 0.05). A switch over to O resulted in TBARS returning to baseline levels. The E membrane prevented an increase in lipid peroxidation during single dialysis, and long-term use of the E membrane also resulted in a decrease in the predialysis lipid peroxidation level. The antioxidant capacity of the E membrane was not enhanced by vitamin C infusion. High doses of vitamin C administered during dialysis using a nonmodified cellulose membrane prevented an increase in lipid peroxidation, most probably due to the enhanced rate of endogenous vitamin E regeneration. [source]


    Effects of histamine receptor blockade on cardiovascular changes induced by 35 GHz radio frequency radiation heating

    AUTONOMIC & AUTACOID PHARMACOLOGY, Issue 1 2004
    J. R. Jauchem
    Summary 1 The role of histamine in heat-induced cardiovascular changes is uncertain. The purpose of this study was to examine effects of histamine H-1- and H-2-antagonism on heart rate, mean arterial blood pressure (MAP), localized body temperature changes, survival times, and lethal body temperatures that occur during the exposure of anaesthetized rats to 35 GHz radio frequency radiation (RFR). 2 Forty-eight ketamine-anaesthetized Sprague,Dawley rats were exposed, in several different treatment groups (n = 8 in each), to 35 GHz RFR at a level that resulted in significant body heating and subsequent death. During irradiation, a continuous increase in heart rate and a biphasic response in blood pressure (initial increase followed by a decrease) were observed in all groups of animals. 3 An H-1-antagonist, diphenhydramine (1 mg kg,1 body wt) and an H-2-antagonist, cimetidine (5 mg kg,1), administered after sustained RFR exposure, failed to reverse the RFR-induced hypotension. High doses of the drugs (5 and 10 mg kg,1, respectively) also did not alter the response. Post-RFR survival time was significantly decreased in the high-dose drug-treated group, compared with vehicle-treated (0.9% NaCl, 50% ethanol and 50% D5W) controls. 4 In experiments in which the two drugs were administered prior to RFR exposure, MAP in animals receiving high-dose antihistamines was significantly depressed compared with that of vehicle-treated animals during the first 35 min of RFR exposure. Antihistamine pretreatment, however, did not alter the total RFR exposure time required for death to occur. 5 In summary, pharmacological blockade of H-1 and H-2 receptors is not beneficial in anaesthetized rats made hypotensive by RFR exposure. This indicates that activation of H-1 and H-2 receptors by histamine does not occur to any significant extent and does not mediate the hypotensive response developed in this model of hyperthermia. [source]


    Embryonic development in the reduced folate carrier knockout mouse is modulated by maternal folate supplementation,,

    BIRTH DEFECTS RESEARCH, Issue 7 2008
    Janee Gelineau-van Waes
    Abstract BACKGROUND: The reduced folate carrier (RFC1) is a ubiquitously expressed integral membrane protein that mediates delivery of 5-methyltetrahydrofolate into mammalian cells. In this study, embryonic/fetal development is characterized in an RFC1 knockout mouse model in which pregnant dams receive different levels of folate supplementation. METHODS:RFC1+/, males were mated to RFC1+/, females, and pregnant dams were treated with vehicle (control) or folic acid (25 or 50 mg/kg) by daily subcutaneous injection (0.1 mL/10 g bwt), beginning on E0.5 and continuing throughout gestation until the time of sacrifice. RESULTS: Without maternal folate supplementation, RFC1 nullizygous embryos die shortly postimplantation. Supplementation of pregnant dams with 25 mg/kg/day folic acid prolongs survival of mutant embryos until E9.5,E10.5, but they are developmentally delayed relative to wild-type littermates, display a marked absence of erythropoiesis, severe neural tube and limb bud defects, and failure of chorioallantoic fusion. Fgfr2 protein levels are significantly reduced or absent in the extraembryonic membranes of RFC1 nullizygous embryos. Maternal folate supplementation with 50 mg/kg/day results in survival of 22% of RFC1 mutants to E18.5, but they develop with multiple malformations of the eyelids, lungs, heart, and skin. CONCLUSIONS: High doses of daily maternal folate supplementation during embryonic/fetal development are necessary for early postimplantation embryonic viability of RFC1 nullizygous embryos, and play a critical role in chorioallantoic fusion, erythropoiesis, and proper development of the neural tube, limbs, lungs, heart, and skin. Birth Defects Research (Part A), 2008. © 2008 Wiley-Liss, Inc. [source]


    Interactions Between Sodium And Angiotensin

    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2001
    Trefor Morgan
    SUMMARY 1. Increased sodium intake causes decreased formation of angiotensin (Ang) II and increased AngII causes increased Na+ retention. 2. Increased sodium intake and increased AngII causes cardiac hypertrophy, but decreased sodium intake regresses cardiac hypertrophy despite high AngII levels. Likewise, decreased Na+ and blockers of the renin,angiotensin system (RAS) in neonatal rats have similar effects on subsequent blood pressure development. 3. Cardiac hypertrophy due to renal hypertension does not regress when the RAS is blocked and rats are on a high salt intake. Likewise, sodium restriction alone does not cause regression; combination of reduced NaCl intake and RAS blockade is required. 4. High doses of perindopril and losartan in combination cause a syndrome in rats on 0.2% NaCl that leads to profound hypotension, polyuria, renal impairment and involution of the heart and death. This is reversed or prevented by a high (4%) NaCl intake, which also prevents the plasma angiotensinogen depletion that occurs with combined blockade on 0.2% NaCl intake. 5. Intake of NaCl and AngII interact at many levels. It is postulated that there is an important interaction at the cellular level that can explain the above events. [source]


    QTc-interval abnormalities in a forensic population

    CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2007
    Sobhi Girgis
    Background,Antipsychotic drugs have been linked to sudden death among psychiatric patients, with a suggestion that prolongation of the QT-interval detectable on a standard electrocardiogram may be linked to fatal cardiac arrhythmias in these circumstances. Patients in secure forensic psychiatric facilities may be particularly likely to be on high-dose antipsychotic medication, and yet, as far as the authors are aware, no study of QT-intervals among such patients has been reported. Aim,To investigate the prevalence of QT-interval abnormalities and associated known risk factors for fatal cardiac arrhythmias in a sample of forensic patients. Method,Participants had a 12-lead electrocardiogram taken at 50 mm/s. Information was collected on their age, gender, psychiatric diagnosis, history of cardiovascular, liver and kidney diseases, and smoking, on all medications and on history of seclusion over the previous 12 months. Analysis was carried out using binary logistic regression. Results,Lower rates of QT-interval abnormalities than might be expected for this population were found. It was also found that a high dose of antipsychotics was associated with QTc prolongation (Adjusted OR = 9.5, 95% CI 2.6,34.2), a result consistent with previous literature. Conclusion,Forensic patients need not be at increased risk of QTc abnormality provided risk factors are properly managed. A high dose of antipsychotic medication increases the risk of QTc prolongation. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Neonatal alcohol exposure impairs acquisition of eyeblink conditioned responses during discrimination learning and reversal in weanling rats

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2007
    Kevin L. Brown
    Abstract Discrimination and reversal of the classically conditioned eyeblink response depends on cerebellar,brainstem interactions with the hippocampus. Neonatal "binge" exposure to alcohol at doses of 5 g/kg/day or more has been shown to impair single-cue eyeblink conditioning in both weanling and adult rats. The present study exposed neonatal rats to acute alcohol intubations across different developmental periods (postnatal day [PND] 4-9 or PND7-9) and tested them from PND26-31 on discriminative classical eyeblink conditioning and reversal. A high dose of alcohol (5 g/kg/day) dramatically impaired conditioning relative to controls when exposure occurred over PND4-9, but produced mild or no impairments when delivered over PND7-9. These findings support previous claims that developmental exposure period plays a critical role in determining the deleterious effects of alcohol on the developing brain. A lower dose of alcohol (4 g/kg/day) delivered from PND4-9,lower than has previously been shown to affect single-cue eyeblink conditioning,also produced deficits on the discrimination task, suggesting that discrimination learning and acquisition of responding to CS+ during reversal may be especially sensitive behavioral indicators of alcohol-induced brain damage in this rat model. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 243,257, 2007. [source]


    Improvement of glycaemic control with rebound following orlistat initiation and cessation associated with minimal weight change

    DIABETIC MEDICINE, Issue 3 2005
    S. González
    Abstract A 57-year-old Caucasian woman with Type 2 diabetes treated for seven years with diet and oral combination hypoglycaemic therapy was referred because of the progressive deterioration of glycaemic control. She was obese (77 kg, BMI = 39.9), hypertensive, hypercholesterolaemic with marked osmotic symptoms (HbA1c 12.2%), therefore she was started on insulin (Human Mixtard 30 b.d.) with metformin therapy. Dietary counselling, recommendations to increase physical activity, and supervised self-injection technique with titration of her insulin were also provided. She was routinely followed-up to assess her progress. Two years later, her glycaemic control remained suboptimal. Average HbA1c was 10.4% despite an increasingly high dose of insulin (94 units/day) although it improved when metformin was increased to 1 g t.d.s. (HbA1c = 9.3%). Her BMI progressively rose from 39.9 to 42.1 (77 to 82.5 kg) despite dietary advice. A trial of orlistat (three months) was commenced, after intensive dietary counselling, that reduced her body weight by 1.5 kg (2% reduction, BMI 41.3). However, her HbA1c improved by 0.5% (from 9.3 to 8.8%). Six months after orlistat was stopped her HbA1c rose to 10.5% and weight increased to 81.8 kg (BMI 41.8). Despite the orlistat treatment broaching NICE guidelines should it have been continued? [source]


    Mephentermine dependence without psychosis: a Brazilian case report

    ADDICTION, Issue 6 2010
    Henrique Faria De Sousa
    ABSTRACT Background Substance abuse is a serious health concern. This report presents the case of a 22-year-old Brazilian man with a history of mephentermine use who fulfils all the criteria for chemical dependence listed by ICD-10. Mephentermine is a sympathomimetic agent derived from methamphetamine which, in Brazil, is restricted to veterinary use. Case description The subject used the substance at a high dose (120 mg) to improve his physical performance while working out at a gym. His symptoms included anorexia and insomnia. After days of intense activity, he felt fatigue and soreness. A physical examination revealed scars on both forearms from the injections and a psychological examination revealed moderate speech and motor agitation. Conclusions Cases such as this may be common among the general public. They should have some bearing upon medical practice and public health policies involving drugs. [source]


    Human sex differences in d -amphetamine self-administration

    ADDICTION, Issue 4 2010
    Andrea R. Vansickel
    ABSTRACT Women and men may respond differently to the effects of stimulants such as amphetamine and cocaine. Aim In order to assess potential sex differences in the reinforcing effects of d -amphetamine, a retrospective-analysis was conducted on data collected from three studies that employed similar d -amphetamine self-administration procedures and used identical subject-rated drug-effect measures. Methods Data from 10 women and 15 men were included in the analysis. In all studies, participants sampled placebo, low (8,10 mg) or high (16,20 mg) dose oral d -amphetamine. Following sampling sessions, participants worked for capsules containing one eighth of the previously sampled dose on a modified progressive-ratio schedule of reinforcement. We hypothesized that women and men would be differentially sensitive to the reinforcing effects of d -amphetamine. A two-way mixed-model analysis of variance (sex and dose) and planned comparisons were used in the statistical analyses. Results The low dose of d -amphetamine functioned as a reinforcer in women, but not men, whereas the high dose of d -amphetamine functioned as a reinforcer in men, but not women. Men self-administered significantly more capsules under the high dose condition than women. Conclusion The results of this study suggest that men are more sensitive to the reinforcing effects of a high dose of d -amphetamine than women. Future research is needed that determines prospectively the reinforcing effects of weight-adjusted doses of d -amphetamine in women and men while controlling for menstrual cycle phase. [source]


    Effects of hunger level and nutrient balance on survival and acetylcholinesterase activity of dimethoate exposed wolf spiders

    ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2002
    Lars-Flemming Pedersen
    Abstract The influence of two nutritional factors (food quantity and quality) on the responses of a wolf spider, Pardosa prativaga (L.K.), to a high dose of the insecticide dimethoate, was investigated in a fully factorial experimental design. Spider groups with different (good and bad) nutrient balance were created by feeding them fruit flies of either high or low nutrient content for 28 days. Both groups were then split into satiated and 14 days starved subgroups. Each of these was further divided into insecticide treated and control halves. Survivorship and acetylcholinesterase (AChE) activity measured on the survivors were used as response variables. Survivorship after topical dimethoate exposure (LD50; 48 h) was influenced by spider body weight, nutrient balance, and starvation. Furthermore, AChE activity was significantly inhibited by dimethoate exposure. A significant interaction between nutrient balance, starvation, and dimethoate exposure revealed synergistic effects of starvation and nutrient imbalance on AChE inhibition by dimethoate in surviving spiders. These results show that the tolerance of non-target arthropods to dimethoate may vary depending on the nutritional history of the animal. [source]


    Tissue-specific metabolic activation and mutagenicity of 3-nitrobenzanthrone in MutaÔMouse,

    ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2008
    Guosheng Chen
    Abstract 3-Nitrobenzanthrone (3-NBA) is a mutagen and suspected human carcinogen detected in diesel exhaust, airborne particulate matter, and urban soil. We investigated the tissue specific mutagenicity of 3-NBA at the lacZ locus of transgenic MutaÔMouse following acute single dose or 28-day repeated-dose oral administration. In the acute high dose (50 mg/kg) exposure, increased lacZ mutant frequency was observed in bone marrow and colonic epithelium, but not in liver and bladder. In the repeated-dose study, a dose-dependent increase in lacZ mutant frequency was observed in bone marrow and liver (2- and 4-fold increase above control), but not in lung or intestinal epithelium. In addition, a concentration-dependent increase in mutant frequency (8.5-fold above control) was observed for MutaÔMouse FE1 lung epithelial cells exposed in vitro. 1-Nitropyrene reductase, 3-NBA reductase, and acetyltransferase activities were measured in a variety of MutaÔMouse specimens in an effort to link metabolic activation and mutagenicity. High 3-NBA nitroreductase activities were observed in lung, liver, colon and bladder, and detectable N -acetyltransferase activities were found in all tissues except bone marrow. The relatively high 3-NBA nitroreductase activity in MutaÔMouse tissues, as compared with those in Salmonella TA98 and TA100, suggests that 3-NBA is readily reduced and activated in vivo. High 3-NBA nitroreductase levels in liver and colon are consistent with the elevated lacZ mutant frequency values, and previously noted inductions of hepatic DNA adducts. Despite an absence of induced lacZ mutations, the highest 3-NBA reductase activity was detected in lung. Further studies are warranted, especially following inhalation or intratracheal exposures. Environ. Mol. Mutagen., 2008. Published 2008 Wiley-Liss, Inc. [source]


    Early Death Due to Severe Organophosphate Poisoning Is a Centrally Mediated Process

    ACADEMIC EMERGENCY MEDICINE, Issue 4 2003
    Steven B. Bird MD
    Objective: To distinguish whether early death from severe organophosphate (OP) poisoning with dichlorvos is mediated through peripheral or central nervous system (CNS) actions. Methods: Wistar rats (n= 72) were randomized to pretreatment with either: normal saline (controls), peripheral anticholinergics (glycopyrrolate [low, medium, or high dose] or nebulized ipratropium bromide), or CNS + peripherally acting anticholinergics (diphenhydramine, nebulized atropine, or injected atropine). All treatments were given prior to a subcutaneous injection of 25 mg/kg dichlorvos (n= 8 per group). Survival was assessed at 10 minutes (early death) and 24 hours (delayed death). Kaplan-Meier (95% confidence intervals [95% CIs]) and chi-squared analysis was then performed to determine differences between treatments. Results: Regardless of treatment, all animals exhibited profound nicotinic effects (fasciculations) without obvious seizures within 2 minutes of poisoning. In rats pretreated with peripherally acting agents, the fasciculations were rapidly followed by reduced motor activity, sedation, and death. Mortality at 10 minutes for saline controls, glycopyrrolate, and ipratropium was 88%, 96%, and 100%, respectively. The single control animal surviving beyond 10 minutes went on to develop peripheral cholinergic manifestations, including hypersalivation, urination, and defecation. Only one of 24 animals treated with injected atropine, nebulized atropine, or diphenhydramine died during the early phase of poisoning; all others survived to 24 hours (p < 0.01). Conclusions: Death in acute, severe OP poisoning is prevented by pretreatment with anticholinergic agents that cross the blood,brain barrier, but not by agents with only peripheral actions. Early death due to OP poisoning appears to be a centrally mediated process. [source]


    Effects of oral electrolyte supplementation on endurance horses competing in 80 km rides

    EQUINE VETERINARY JOURNAL, Issue S36 2006
    F. SAMPIERI
    Summary Reasons for performing study: There is no evidence that use of oral electrolyte pastes enhances performance in competing endurance horses. Objective: To ascertain whether oral administration of a high dose (HD) of sodium chloride (NaCl) and potassium chloride (KCl) to endurance horses would differentially increase water intake, attenuate bodyweight (bwt) loss and improve performance when compared to a low dose (LD). Methods: A randomised, blinded, crossover study was conducted on 8 horses participating in two 80 km rides (same course, 28 days apart). Thirty minutes before and at 40 km of the first ride 4, horses received orally 0.2 g NaCl/kg bwt and 0.07 g KCl/kg bwt. The other 4 received 0.07 g NaCl/kg bwt and 0.02 g KCl/kg bwt. Horses received the alternate treatment in the second ride. Data were analysed with 2-way ANOVA for repeated measures (P<0.05). Results: Estimated water intake was significantly greater with HD both at the 40 km mark and as total water intake; however, differences in bwt loss and speed between HD and LD were not found. Treatment significantly affected serum Na+, Cl,, HCO3, pH and water intake, but not serum K+ or bwt. Serum Na+ and Cl, were significantly higher at 80 km when horses received HD, but no differences were found in early recovery. Venous HCO3 and pH were significantly lower throughout the ride and in early recovery when horses received HD. Conclusions and potential relevance: Other than enhancing water intake, supplementing endurance horses with high doses of NaCl and KCl did not provide any detectable competitive advantage in 80 km rides. Further, the elevated serum electrolyte concentrations induced with HD might not be appropriate for endurance horses. [source]


    PRECLINICAL STUDY: Is withdrawal hyperalgesia in morphine-dependent mice a direct effect of a low concentration of the residual drug?

    ADDICTION BIOLOGY, Issue 4 2009
    Vardit Rubovitch
    ABSTRACT Withdrawal of opioid drugs leads to a cluster of unpleasant symptoms in dependent subjects. These symptoms are stimulatory in nature and oppose the acute, inhibitory effects of opiates. The conventional theory that explains the opioid withdrawal syndrome assumes that chronic usage of opioid drugs activates compensatory mechanisms whose stimulatory effects are revealed upon elimination of the inhibitory opioid drug from the body. Based on previous studies that show a dose-dependent dual activity of opiates, including pain perception, we present here an alternative explanation to the phenomenon of withdrawal-induced hyperalgesia. According to this explanation, the residual low concentration of the drug that remains after cessation of its administration elicits the stimulatory withdrawal hyperalgesia. The goal of the present study was to test this hypothesis. In the present study we rendered mice dependent on morphine by a daily administration of the drug. Cessation of morphine application elicited withdrawal hyperalgesia that was completely blocked by a high dose of the opiate antagonist naloxone (100 mg/kg). Similarly, naloxone (2 mg/kg)-induced withdrawal hyperalgesia was also blocked by 100 mg/kg of naloxone. The blockage of withdrawal hyperalgesia by naloxone suggested the involvement of opioid receptors in the phenomenon and indicated that withdrawal hyperalgesia is a direct effect of a residual, low concentration of morphine. Acute experiments that show morphine- and naloxone-induced hyperalgesia further verified our hypothesis. Our findings offer a novel, alternative approach to opiate detoxifications that may prevent withdrawal symptoms by a complete blockage of the opioid receptors using a high dose of the opioid antagonist. [source]