Distribution of beta-lactamases and phenotype analysis in clinical strains of Acinetobacter calcoaceticus

One hundred clinical strains of Acinetobacter calcoaceticus isolated from 1981 to 1986 were screened for enzymatic resistance to beta-lactam antibiotics. Fourteen beta-lactam antibiotics were tested and four phenotypes were defined on the basis of enzymatic resistance and of susceptibility to the following beta-lactams: ticarcillin, piperacillin, cefotaxime, and ceftazidime. The resistance of A. calcoaceticus to beta-lactam antibiotics was predominantly due to beta-lactamases, which were produced by 81% of the strains. In most (71%) of the beta-lactamase producing strains, a penicillinase of the TEM type was observed; in 9% of the strains, all isolated since 1985, a CARB-type penicillinase with a pI 6.3 was observed. The presence of a cephalosporinase type enzyme was detected in acinetobacter strains isolated since 1981 and its incidence increased in 1986. Multiple beta-lactamases (penicillinase plus cephalosporinase) were observed in 32% of the strains.     

Lack of correlation between lithium pharmacokinetic parameters obtained from plasma and saliva

One tablet containing 755 mg of lithium tryptophanate (10.8 mEq of lithium) was administered to eight healthy volunteers. The main pharmacokinetic parameters for the group of subjects were estimated. Pharmacokinetic parameters (mean +/- SD) from plasma and saliva were respectively: half life (t1/2) 17 +/- 6 vs. 21.8 +/- 14 h; mean residence time 23.7 +/- 7.4 vs. 24.4 +/- 15.3 h; total clearance 30.6 +/- 9.3 vs. 28.6 +/- 6.2 ml/h/kg; and apparent volume of distribution 0.71 +/- 0.20 vs. 0.84 +/- 0.37 L/kg. Although the mean pharmacokinetic parameters in plasma and saliva were similar, there was no significant correlation between the calculated parameters in the individual subject (p greater than 0.05). The usefulness of monitoring salivary levels of lithium is questionable.     

Neurosteroids and cholinergic systems: implications for sleep and cognitive processes and potential role of age-related changes

Rationale The neurosteroids pregnenolone sulfate (PREGS), dehydroepiandrosterone sulfate (DHEAS) and allopregnanolone (3α,5α THPROG) have been implicated as powerful modulators of memory processes and sleep states in young and aged subjects with memory impairment. As these processes depend on the integrity of cholinergic systems, a specific effect of neurosteroids on these systems may account for their effects on sleep and memory.Objective To review the evidence for a specific and differential effect of neurosteroids on cholinergic systems.Methods We carried out keyword searches in “Medline” to identify articles concerning (1) the effects of neurosteroids on cholinergic systems, sleep and memory processes, and (2) changes in neurosteroid concentrations during aging. Few results are available for humans. Most data concerned rodents.Results Peripheral and central administrations of PREGS, DHEAS, and 3α,5α THPROG modulate the basal forebrain and brainstem projection cholinergic neurons but not striatal cholinergic interneurons. Local administration of neurosteroids to the basal forebrain and brainstem cholinergic neurons alters sleep and memory in rodents. There are a few conflicting reports concerning the effects of aging on neurosteroid concentrations in normal and pathological conditions.Conclusions The specific modulation of basal forebrain and brainstem cholinergic systems by neurosteroids may account for the effects of these compounds on sleep and memory processes. To improve our understanding of the role of neurosteroids in cholinergic systems during normal and pathological aging, we need to determine whether there is specific regionalization of neurosteroids, and we need to investigate the relationship between neurosteroid concentrations in cholinergic nuclei and age-related sleep and memory impairments.     

Thyroglobulinemia in thyroid pathology

Authors have selected 1928 measurements of thyroglobulin and studied their value in the thyroid pathology. They show that elevated values of thyroglobulin, the only one response in this pathology, can, even if isolated, be the mode of revelation of thyroid illness. They insist, in order to explain this fact, on the presence of a "sixth factor" which depends upon the quality of the thyroid tissue.     

Lack of hepatotoxicity after long-term administration of cyanamide in rats: a histological and biochemical study

An experimental long-term hepatotoxicity study of cyanamide in Sprague-Dawley and Wistar rats has been carried out. After six months oral administration of cyanamide (2.7 and 25 mg/kg/day) no significant histological changes have been observed in the liver. Similarly, a one year intraperitoneal administration of 8 and 16 mg/kg/day has not induced any hepatic change. Specifically, no inclusion bodies in any cyanamide treated rat have been detected. Moreover, hepatic biochemical parameters have shown no significant impairment of hepatic function at doses used in human therapy (0.5-1 mg/kg).     

Cyst of the medial meniscus of the knee

We had the opportunity to observe a case of cyst of the medial meniscus of the knee. We observed unusual findings; association with a meniscal tear and communication through the tear with the articular cavity.