Exertional heatstroke and muscle metabolism: an in vivo 31P-MRS study.

An impairment of muscle energy metabolism has been suggested as a predisposing factor for, as well as a consequence of exertional heatstroke (EHS). Thirteen young men were investigated 6 months after a well-documented EHS using 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS). The relative concentrations of ATP, phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters (PME), and the intracellular pH (pHi) were determined at rest, during a graded standardized exercise protocol (360 active plantar flexions) and during recovery. Also the leg tissue blood flow was determined by venous occlusion plethysmography during the MRS procedure. Sixteen age-matched healthy male volunteers served as control group. In resting muscle, there were no significant differences between the groups as regards pHi, Pi/PCr, and ATP/PCr+Pi+PME ratios. During steady state exercise conditions, effective power outputs were similar for both groups at each level of exercise: 20, 35, and 50% of maximal voluntary contraction (MVC) of the calf muscle. No significant differences were shown between the two groups in Pi/PCr, pHi, or changes of leg blood flow at each level of exercise. At 50% MVC, Pi/PCr was 0.48 +/- 0.08 vs 0.47 +/- 0.05 (P = 0.96), pHi was 6.94 +/- 0.03 vs 6.99 +/- 0.02, respectively (P = 0.13). Finally, the rate of PCr resynthesis during recovery was not significantly different between the two groups: t1/2 PCr = 0.58 +/- 0.07 vs 0.50 +/- 0.05 min, respectively (P = 0.35). Therefore, no evidence of an impairment of muscle energy metabolism was shown in the EHS group during a standardized submaximal exercise using 31P-MRS performed 6 months after an EHS.     

Antibody avidity: use for the diagnosis of HIV early infection

Determination of IgG avidity is useful to distinguish primary infection from reactivation or reinfection in viral, parasitic or bacterial infections. For diagnosis of HIV type 1 primary infection, the detection of IgM antibodies is often useless since they are also found in chronic infection. The usual serology (Elisa, western-blot, p24 antigen) may present no interest if done too late (more than 2 or 3 months after infection). Therefore, we have developed a test to determine the avidity of anti-HIV1 antibodies, using 1 M guanidine as denaturing agent. We have adapted the measurement of avidity to the Axsym automatic system for a routine use. Indeed, since requests for avidity determinations are sporadic, the use of microplates is not convenient. Using this assay, we found a low avidity (less than 50%) in immunocompetent and recent infected patients (less than 6 months), compared to old infected patients (more than 12 months) who had high avidity (80 to 100%). However, early treated patients (in the 6 months after contamination) had also low avidities but with a slower development of antibody maturation (8 to 27 months versus 2 to 8 months in non treated patients). To conclude, the determination of the anti-HIV1 avidity, according to the proper procedures explained here (notion of treatment and/or serious immunodepression), may help the physician to date the infection in each new infected patient who might benefit from an early treatment.     

Glucuronidation of drugs by hepatic microsomes derived from healthy and cirrhotic human livers

Pharmacokinetic studies demonstrated that the decrease in drug biotransformation in hepatic failure depends on the metabolic pathways involved. To test whether glucuronidation reactions supported by UDP-glucuronosyltransferases are differentially affected in such conditions, we investigated the in vitro glucuronidation of four selected drugs and xenobiotics (zidovudine, oxazepam, lamotrigine, and umbelliferone) by using microsomes from human healthy and unhealthy (cirrhosis, hepatitis) livers as enzyme sources. Theses substances are glucuronidated by several UDP-glucuronosyltransferase isoforms. Lidocaine N-deethylation activity measured concomitantly was used as a positive control, because the inhibition of this reaction in patients with hepatic diseases is well documented. The metabolic clearances of zidovudine and lidocaine were decreased significantly in liver cirrhosis (0.17 versus 0.37 microliter/min/mg protein and 0.40 versus 2.73 microliter/min/mg protein, respectively) as a consequence of a decrease of their corresponding Vmax of metabolism. By contrast, the metabolic clearances of oxazepam, umbelliferone, and lamotrigine glucuronidation remained unchanged. Previous studies reported that the in vivo oral clearances of zidovudine and lidocaine were decreased by 70% and 60%, respectively, in cirrhotic livers, whereas those of lamotrigine and oxazepam were not affected. Consequently, it is likely that the in vitro metabolic data, which support the in vivo results, therefore could contribute to reasonably predict the level of impairment of hepatic clearance in patients with liver cirrhosis.     

Randomized comparison of transurethral electroresection and holmium: YAG laser vaporization for symptomatic benign prostatic hyperplasia

OBJECTIVE: To evaluate the safety and efficacy of holmium:YAG laser vaporization v transurethral electroresection (TURP) for benign prostatic hyperplasia. PATIENTS AND METHODS: Thirty-six patients were randomized. Two laser procedures (60 to 80 W) were performed for one TURP. Symptom Score, peak flow rate, potency, and ejaculation status were measured at baseline and at 1, 3, 6, and 12 months. RESULTS: The mean operative time was 75 minutes for laser and 56 minutes for TURP (P = 0.0407). With a mean laser energy delivered of 103.6 kJ, hemostasis was satisfactory during vaporization. The mean catheterization time was 1.7 and 2.1 days in the laser and TURP group, respectively. For the laser and TURP groups, the mean AUA Score improved from 20 preoperatively to 7 and from 24.1 to 5, respectively, at 12 months. The mean peak flow increased from 8.4 to 19.5 mL/sec and from 7.6 to 16.8 ml/sec, respectively, at 12 months. These results are not statistically different. No significant initial dysuria occurred. No significant difference between the groups appeared in potency or ejaculatory status during the follow-up. One patient in the laser group (Day 5) and two in the TURP group (2nd and 6th month) had to undergo a second procedure to relieve obstruction. CONCLUSION: Although taking slightly longer to accomplish, holmium:YAG laser vaporization of BPH provides early results very similar to those of TURP with a shorter catheterization time and no initial dysuria or pain.     

Systematic mammographic screening for breast cancer in asymptomatic women]

It appears that the mortality rate from breast cancer decreases in 50-year-old (and over) women submitted to mammographic screening. Since 1980, the Unit of Cancer Prevention of the UCL is proposing mammographic screening to women with normal clinical examination but belonging to a "high-risk" group. Among the 5651 mammographies which were performed on 2924 women, 24 biopsies have been proposed and 16 cases of cancer have been diagnosed. 5.5% breast cancers have been detected. This result is consistent with the average figures reported in the screening programmes abroad. Questions about the age at which cancer screening should start and about the number of views that should be taken are also discussed.     

Guidelines for proton pump inhibitor prescriptions in paediatric intensive care unit

International Journal of Clinical Pharmacy - Background Stress ulcer prophylaxis (SUP) is recommended in some situations to prevent upper gastrointestinal bleeding and is a component of standard...     

Maternal citrulline supplementation enhances placental function and fetal growth in a rat model of IUGR: involvement of insulin-like growth factor 2 and angiogenic factors

Objective: To determine the effects of maternal citrulline supplementation on fetal growth and placental efficiency in a rat model of intrauterine growth restriction (IUGR) induced by maternal protein restriction.

Methods: Pregnant Sprague–Dawley rats were randomly assigned to three groups: NP (receiving a control 20% protein diet), LP (a 4% protein diet), or LP-CIT (an LP diet along with L-citrulline, 2?g/kg/d in drinking water). On the 15th and 21st day of gestation (GD15 and GD21, respectively), dams underwent a C-section, by which fetuses and placentas were extracted. The expression of genes involved in placental growth and angiogenesis was studied by quantitative RT-PCR.

Results: Maternal citrulline supplementation increased fetal weight at GD21, and fetal weight/placental weight ratio, an index of placental efficiency, from mid gestation (p?Igf2-P0, a placenta-specific variant of insulin-like growth factor 2 (Igf2) gene, and Vegf and Flt-1, involved in angiogenic pathways, was enhanced in the LP-CIT group (versus NP, p?p?p?Igf2-P0, Vegf, and Flt-1, respectively).

Conclusions: In a model of IUGR induced by protein deprivation, citrulline enhances fetal growth, placental efficiency, and the expression of genes involved in angiogenesis. The relevance of such effect in human pregnancies complicated by IUGR warrants further study.