Chemistry Tests (chemistry + test)

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Selected Abstracts

Impaired water maze learning performance without altered dopaminergic function in mice heterozygous for the GDNF mutation

R. Gerlai
Abstract Exogenous glial cell line-derived neurotrophic factor (GDNF) exhibits potent survival-promoting effects on dopaminergic neurons of the nigrostriatal pathway that is implicated in Parkinson's disease and also protects neurons in forebrain ischemia of animal models. However, a role for endogenous GDNF in brain function has not been established. Although mice homozygous for a targeted deletion of the GDNF gene have been generated, these mice die within hours of birth because of deficits in kidney morphogenesis, and, thus, the effect of the absence of GDNF on brain function could not be studied. Herein, we sought to determine whether adult mice, heterozygous for a GDNF mutation on two different genetic backgrounds, demonstrate alterations in the nigrostriatal dopaminergic system or in cognitive function. While both neurochemical and behavioural measures suggested that reduction of GDNF gene expression in the mutant mice does not alter the nigrostriatal dopaminergic system, it led to a significant and selective impairment of performance in the spatial version of the Morris water maze. A standard panel of blood chemistry tests and basic pathological analyses did not reveal alterations in the mutants that could account for the observed performance deficit. These results suggest that endogenous GDNF may not be critical for the development and functioning of the nigrostriatal dopaminergic system but it plays an important role in cognitive abilities. [source]

An obesity drug sibutramine reduces brain natriuretic peptide (BNP) levels in severely obese patients

D. Taner Ertugrul
Summary Objectives:, Sibutramine is a selective inhibitor of the reuptake of monoamines. Plasma levels of brain natriuretic peptide (BNP) appear to be inversely associated with body mass index (BMI) in subjects with and without heart failure for reasons that remain unexplained. The aim of this study was to investigate the possible influence of sibutramine treatment on BNP levels in severely obese patients. Methods:, Fifty-two severely obese female patients with BMI > 40 kg/m2 were included to this study. The women were recommended to follow a weight-reducing daily diet of 25 kcal/kg of ideal body weight. During the treatment period, all patients were to receive 15 mg of sibutramine once a day. Blood chemistry tests were performed before the onset of the medication and after 12 weeks of treatment. Results:, None of the subjects was withdrawn from the study because of the adverse effects of sibutramine. Body weight (108.8 ± 13.3 kg vs. 101.7 ± 15.6 kg, p < 0.001), BMI (44.6 ± 4.6 kg/m2 vs. 41.8 ± 5.7 kg/m2, p < 0.001) and BNP [8.6 (0.5,49.5) ng/l vs. 3.1 (0.2,28.6) ng/l, p = 0.018] levels were significantly decreased after 12 weeks of sibutramine treatment. Total cholesterol (5.19 ± 0.90 mmol/l vs. 4.82 ± 1.05 mmol/l respectively; p < 0.001), low-density lipoprotein-cholesterol (3.26 ± 0.86 mmol/l vs. 2.99 ± 0.40 mmol/l respectively; p = 0.008), levels were significantly decreased; however, there was no significant alteration in high-density lipoprotein-cholesterol and triglyceride levels. Conclusion:, This study has shown a decrease in BNP levels which may lead to improvement in cardiac outcome after sibutramine treatment. Further randomised studies are needed to be conducted to clarify the relationship between sibutramine and BNP. [source]

Acute generalized exanthematous pustulosis mimicking toxic epidermal necrolysis

Arnon D. Cohen MD
A 91-year-old patient presented with a nonfebrile, pruritic, widespread eruption that appeared 10 days after starting therapy with cefuroxime tablets, 1000 mg/day, due to stasis dermatitis with secondary infection. The patient was also treated with paracetamol tablets, 500,1000 mg/day, 10 days before the onset of the eruption. Previous diseases included congestive heart disease, hyperglycemia, and ectropion. There was no personal or family history of psoriasis. Additional medications, taken for more than 2 years at the time of the eruption, included indomethacin, captopril, hydrochlorothiazide, isosorbide-5-mononitrate tablets, and a combination drug Laxative®. Examination revealed widespread erythema involving 95% of the total body surface area, with numerous 1,2 mm nonfollicular pustules (Fig. 1). There was no predilection to the body folds. Within 24 h of hospitalization, during intravenous therapy with cefuroxime, the patient's condition worsened and bullae containing clear fluid appeared. Nikolsky's sign was positive on erythematous skin, and eventually skin detachment involved 41% of the total body surface area (Fig. 2). There were no target or target-like lesions and there was no involvement of the mucous membranes. Figure 1. Numerous, 1,2 mm, nonfollicular pustules, with confluence (viewed in the lower left part of the photograph), on erythematous skin Figure 2. Widespread skin detachment An early biopsy from a pustule revealed subcorneal and intraepidermal spongiform pustules, papillary edema, perivascular mononuclear infiltrate with a few eosinophils in the dermis, and leukocytoclastic vasculitis. A later biopsy showed similar findings with no evidence of full-thickness epidermal necrosis or necrotic keratinocytes. Direct immune fluorescence (DIF) taken from erythematous skin was negative. Laboratory studies showed the following results: sedimentation rate, 80 mm/h; white blood cell count, 26,200/mm3 with 87% polymorphonuclears and 1.8% eosinophils; hemoglobin, 13.0 g/dL; albumin, 2.8 g/dL (normal, 3.5,5.5 g/dL); other blood chemistry tests were normal. Immunologic studies for rheumatoid factor, antinuclear antibodies, antismooth muscle antibodies, antiparietal cell antibodies, antimitochondrial antibodies, C3, and C4 were normal or negative. Serology for venereal disease research laboratory (VDRL) test, Epstein,Barr virus, cytomegalovirus, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and antistreptolysin titer was negative. Chest X-ray was normal. Blood cultures were negative. Swab cultures taken from the pustules revealed Staphylococcus aureus as well as coagulase-negative Staphylococcus. All systemic drugs, including intravenous cefuroxime, were withdrawn with close monitoring for signs of heart failure or infection. Topical therapy consisted of application of wet dressings. Within 10 days, the eruption resolved with re-epithelialization of the erosions and the appearance of widespread post-pustular desquamation (Fig. 3) Figure 3. Post-pustular desquamation on the trunk [source]

Relationship Between RDX Properties and Sensitivity


Abstract An interlaboratory comparison of seven lots of commercially available RDX was conducted to determine what properties of the nitramine particles can be used to assess whether the RDX has relatively high or relatively low sensitivity. The materials chosen for the study were selected to give a range of HMX content, manufacturing process and reported shock sensitivity. The results of two different shock sensitivity tests conducted on a PBX made with the RDX lots in the study showed that there are measurable differences in the shock sensitivity of the PBXs, but the impact sensitivity for all of the lots is essentially the same. Impact sensitivity is not a good predictor of shock sensitivity for these types of RDX. Although most RDX that exhibits RS has low HMX content, that characteristic alone is not sufficient to guarantee low sensitivity. A range of additional analytical chemistry tests were conducted on the material; two of these (HPLC and DSC) are discussed within. [source]

Author response to: Reference values for clinical chemistry tests during normal pregnancy

A Larsson
No abstract is available for this article. [source]

Reference values for clinical chemistry tests during normal pregnancy

A Larsson
Objective, Reference values are usually defined based on blood samples from healthy men or nonpregnant women. This is not optimal as many biological markers changes during pregnancy and adequate reference values are of importance for correct clinical decisions. There are only few studies on the variations of laboratory tests during normal pregnancies, especially during the first two trimesters. It is thus a need to establish such reference values. Design, Longitudinal study of laboratory markers in normal pregnancies. Setting, Uppsala University Hospital, Sweden. Population, Healthy pregnant females. Methods, We have studied 25 frequently used laboratory tests during 52 normal pregnancies. Each woman was sampled up to nine times and the samples were divided according to collection time into the following groups: gestational week 7,17; week 17,24; week 24, 28; week 28,31; week 31,34; week 34,38; predelivery (0,2 weeks before delivery) and postpartum (>6 weeks after delivery). The 2.5 and 97.5 percentiles for these markers were calculated according to the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values. Results, Reference intervals are reported for plasma alanine aminotransferase, albumin, alkaline phosphatase, pancreas amylase, apolipoprotein A1, apolipoprotein B, aspartate aminotransferase, bilirubin, calcium, chloride, creatinine, cystatin C, ferritin, ,-glutamyltransferase, iron, lactate dehydrogenase, magnesium, phosphate, potassium, sodium, transferrin, triglycerides, thyroid-stimulating hormone, urate and urea during these pregnancy periods. Conclusions, Most of the analytes change during normal pregnancy. It is thus of importance to use special reference values during pregnancy. [source]