The effect of acute fluid consumption on measures of impedance and percent body fat using leg-to-leg bioelectrical impedance analysis

OBJECTIVE: To examine the effect of acute fluid consumption on measures of impedance and percent body fat (%BF) using a common leg-to-leg bioelectrical impedance analyzer system. DESIGN: Cross-sectional design with treatment order determined using a counterbalanced assignment. SETTING: University laboratory. SUBJECTS: In total, 21 recreationally active men (mean age 19.7 +/- 1.0 years; body mass index 24.2 +/- 2.3 kg/m2) volunteered to participate in this study. INTERVENTION: Subjects had their body composition assessed on three separate occasions. After an initial baseline body composition measurement, subjects consumed 591 ml of water (H2O), a carbohydrate/electrolyte drink (CHOE), or received nothing, used as the control (CON). Subjects were reassessed 20, 40, and 60 min after baseline (POST). Urine specific gravity (USG) was recorded at baseline and 60 min POST to assess hydration state. RESULTS: There were no significant changes in impedance or total body water (TBW) for any of the measurement time periods after drinking H2O or a CHOE beverage. Body weight (BW) (P < 0.0001) and %BF (P < 0.02) increased significantly 20 min POST and remained elevated at the 40 and 60 min POST time periods. After drinking, USG significantly decreased (P<0.0001) 60 min POST from baseline. For the CON trial, there were no significant changes in BW, %BF, TBW, or USG over time. CONCLUSIONS: Fluid consumption had no effect on lower-body impedance despite causing significant changes in hydration state. A slight overestimation in %BF (approximately 0.5%) was observed due to increased BW in the H20 and CHOE trials. This finding may have little practical significance when assessing body composition by LBIA.     

Economics of atypical antipsychotics in bipolar disorder: a review of the literature

Economic evaluations are increasingly being used by policy makers to evaluate the relative costs and benefits of healthcare interventions. These analyses provide economic and clinical evidence to decision makers seeking to make recommendations on treatment alternatives for patients. This article describes the economic evidence on the atypical antipsychotics currently approved for the treatment of bipolar disorder. This area remains under-researched. A literature search identified only six relevant studies of atypical antipsychotics in bipolar disorder: two retrospective database analyses, three economic analyses alongside clinical trials and one cost-effectiveness analysis. Based on the limited available studies, there appears to be no significant difference in healthcare resource use between olanzapine, quetiapine, risperidone and valproate semisodium (divalproex sodium; an antiepileptic drug and a standard treatment for mania associated with bipolar disorder). While a cost-effectiveness study for the UK found haloperidol (a conventional antipsychotic) to be more cost effective than atypical antipsychotics, these results must be considered with caution because of the non-inclusion of adverse effects in the model. No economic data are available for aripiprazole, clozapine or ziprasidone in bipolar disorder. Until more economic evidence becomes available, the economic implications of atypical antipsychotic treatment in patients with bipolar disorder are unlikely to significantly impact on prescribing and treatment patterns. Future economic studies evaluating atypical antipsychotics in bipolar disorder should address the issue of long-term costs and effectiveness to reflect the chronic nature of the disease, the variety of health states that patients may experience and the range of treatments they may receive. A better understanding of the complex interplay between effectiveness, safety, quality of life, adherence and resource use should ultimately contribute to improving the treatment of bipolar disorder.     

Five-hour renal functional evaluation

Children with urogenital disease frequently require evaluation of glomerular and tubular functions. Herein is presented a practical method of performing glomerular and tubular functional studies requiring short time periods and utilizing readily available laboratory techniques.     

Permeability of selected drugs and chemicals across the blood-testis barrier of the rat.

Physiological studies by Setchell and others have described the existence of a blood-testis barrier (BTB) surrounding the seminiferous tubules of the mammalian testis. These studies were initiated to better define the role of the BTB with regard to the penetration of exogenous chemicals to male germ cells. The rete testis was cannulated in rats and fluid was collected. Test chemicals or drugs were usually administered by continuous i.v. infusion. Permeability of nonelectrolytes of various molecular sizes, acidic compounds with varying partition coefficients and pKalpha values, such as salicylic acid, barbiturates, and sulfonamides, across the BTB were studied. Permeability of nonelectrolytes was demonstrated to be dependent upon their molecular size, suggesting bulk flow through water-filled pores. On the other hand, permeability of acidic drugs with varying pKalpha values depended upon their partition coefficients. Transport of these chemicals from blood to seminferous tubules closely resembled their transport from blood to cerebrospinal fluid. It appears that the BTB is a complex multicellular system composed of membranes surrounding the semiferous tubules and the several layers of spermatogenic cells organized within the tubules, which restrict the permeability to the male germ cells of many foreign compounds. This must be borne in mind when extra-polating data from in vitro mutagenic test systems to man.     

Transmission of murine leukemia virus (Scripps) from parent to progeny mice: a comparison of assay systems.

Transmission of murine leukemia virus (MuLV) from parent to progeny C3H/St and C57BL/St mice was examined by four assay systems: 1) recovery of infectious NB-tropic MuLV from spleen cultures, 2) the radioimmunoassay for p30 antigenemia, 3) morphologic examination for lymphoma development, and 4) the indirect fluorescent antibody technique for antinuclear antibodies (ANA). Transmission of MuLV (Scripps) occurred in 90-100% of C3H/St and C57BL/St progeny nursed by mothers with p30 antigenemia. All assays except ANA were equally sensitive for the determination of MuLV transmission in C3H/St mice, but the incidence of transmission in C57BL/St mice was determined only by assays of their cultured spleens for MuLV. Incidences of ANA were increased in all generations of C57BL/St mice compared with controls; the route of transmission of MuLV (Scripps) was not a factor. Only C3H/St mice infected by virus transmitted from parent to progeny developed ANA. Infectious MuLV was invariably recovered from spleens cultured from mice with p30 antigenemia, which was present in all mice that developed lymphoma. NB-tropic MuLV was also recovered after prolonged cultivation from spleens of 75% of C57BL/St progeny mice that did not develop p30 antigenemia. These suggested that MuLV (Scripps) could exist either as a productive persistent or nonproductive latent infection in C57BL/St mice.