It is well recognized that the sensitivity of animals to lipopolysaccharide (LPS) endotoxin varies tremendously. And, it has been recently observed that Sprague-Dawley rats dramatically increase the activity of hepatic endogenous antioxidative enzyme systems after LPS administration. This finding suggests that the relative resistance of rats to LPS may be related to a concomitant increase in the activities of the hepatic antioxidant systems. This study was designed to examine if the above reported hepatic change in rats given LPS could be observed at the systemic level. Male Sprague-Dawley or Wistar rats, weighing 250 - 350 g, were given increasing doses (10 - 100 mg/kg) of LPS i.p. under 1.0% isoflurane anesthesia. Antioxidant capacity (AOC), blood gas analysis, and the cardiovascular parameters of the arterial blood of animals were determined over a 4 hour period following LPS administration. In addition, we studied the effect of pretreatment with the non-specific nitric oxide synthase inhibitor, L-N(G)-Nitroarginine methyl ester hydrochloride (L-NAME), given 50 mg/kg s.c. one and 24 hours before the administration of 20 mg/kg LPS i.p. in Sprague-Dawley rats. Rats given sufficiently high doses of E. coli LPS to produce behavioral effects also showed increased plasma AOCs in the early period after the administration of LPS. Similar changes were noted in Sprague-Dawley and Wistar rat strains, but at different doses that reflect their differential sensitivities to the LPS induced inflammatory response. Also, the resistance of the Sprague-Dawley strain of rats to LPS was not altered by the prior administration of L-NAME, nor was the plasma AOC altered. In conclusion, our study suggests that the rat strains are relatively resistant to develop the toxic signs of LPS in the early period after the administration of LPS, especially in Sprague-Dawley rats. Moreover, endotoxin-induced increases in plasma AOC may contribute to the rats' resistance to LPS intoxication.
Animal ; Antioxidants/analysis* ; Blood Pressure/drug effects ; Escherichia coli/pathogenicity* ; Lipopolysaccharides/toxicity* ; Male ; NG-Nitroarginine Methyl Ester/pharmacology ; Nitric-Oxide Synthase/physiology ; Nitric-Oxide Synthase/antagonists & inhibitors ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar

AIMTo analyse the possible effect of seasonal variation on semen parameters.

METHODSThe participants consisted of 1,688 men attending the andrology laboratory between 1991 and 1997 for reduced fertility in the couple. Semen analysis was performed according to the WHO manual. The 84 individual months of the study period were each assigned to one of the three groups according to the average monthly outside temperature; Group A (temperature < 4.4 degrees C), Group B (4.4 degrees C - 13.3 degrees C) and Group C (>13.3 degrees C).

RESULTSWhen comparing the different sperm parameters, the morphology was significantly better in Group C. However, when the smokers were analysed separately, this difference disappeared and significant seasonal variations were found in sperm density, total sperm count, motility and total motile sperm; they were deteriorated in the warmer season. In non-smokers, no such negative effect of increased temperature was observed.

CONCLUSIONSperm quality is influenced by seasonal factors. Increased environmental temperature, (maybe also light exposure) has an additional negative effect on the spermatogenesis in smokers, leading to reduced sperm quality in men with borderline fertility.

Adult ; Fertility ; drug effects ; physiology ; Humans ; Male ; Reference Values ; Seasons ; Semen ; physiology ; Smoking ; physiopathology ; Sperm Count ; Sperm Motility ; Switzerland ; Temperature

Objective: To determine the utility of a highly sensitive troponin assay when utilized in the emergency department. Methods The FAST-TRAC study prospectively enrolled >1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician’s clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible.Trial registration ClinicalTrials.gov Identifier NCT00880802