[Bacteremia caused by vancomycin-resistant Enterococcus faecalis. Report of 2 cases]

The rising concern about nosocomial bacteremia due to vancomycin-resistant E. faecalis in Spanish hospitals. Retrospective review of the medical records of two patients with nosocomial bacteremia due to E. faecalis resistant to vancomycin. Both patients (a 78 years-old male and a 65 years-old female) were admitted in two separate hospital units. None of them had been previously treated with vancomycin, and both patients had severe underlying diseases. The two strains isolated showed high-level vancomycin and teicoplanin resistance, although they were sensitive to daptomycin. No other strain with high level glycopeptide antibiotic resistance was isolated in the hospital during the following 23 months. This occasional resistance to glycopeptides among enterococci has been shown also in other Spanish hospitals. The increasing incidence of penicillin and aminoglycoside resistance among enterococci in our environment could have a practical impact, either for the clinical laboratory and/or for therapeutic decisions in patients with infections due to this microorganism.

[The differential diagnosis between pleural exudates and transudates: the value of cholesterol]

BACKGROUND

The evaluation of a patient with pleural effusion depends on its classification as exudate or transudate. Many criteria have been established but none has a 100% sensitivity and specificity. The aim of the present study was to assess the value of the cholesterol level to differentiate between exudate and transudate and to establish its utility as compared with other differential criteria.

METHODS

104 patients with pleural effusion of well defined etiology, permitting their classification into 56 exudates and 48 transudates, were evaluated. In all, Light's criteria were established and cholesterol values in pleural effusion and serum were measured and compared.

RESULTS

Using the lactate dehydrogenase level (LDH) in pleural fluid (PF) and the ratios of LDH and proteins in PF and serum, 100% of exudates and 83% of transudates were correctly classified. A cholesterol level of 40 mg/dl or higher best separated exudates and transudates, with a sensitivity of 96% and a specificity of 92% for exudates. A ratio of 0.3 or higher between cholesterol levels in PF and serum was shown to have a high sensitivity (96%) and lower specificity (85%) for exudates. The highest specificity (92%) was achieved when the protein ratio in PF and serum was combined with PF cholesterol.

CONCLUSIONS

The cholesterol level in pleural fluid and the ratio between this value and that in serum are highly useful parameters to differentiate between exudates and transudates.

Gastric mucosal somatostatin-like immunoreactivity in peptic ulcer

Somatostatin (SS) has been reported to exert potent inhibitory effects on gastric acid, pepsin and gastrin secretion. Although still controversial, the results of several studies have shown a possible influence of a local decrease in gastric somatostatin in the physiopathologic characteristics of peptic ulcer disease. In the present study, immunoreactive SS content (SLI) of antral (SLI-a), corpal (SLI-c) and fundic (SLI-f) mucosal extracts was measured by radioimmunoassay (RIA) in control patients (C) and in those patients with duodenal ulcer (DU) or gastric ulcer (GU) to further study a possible role of SS in peptic ulcer disease. Fifty-five patients (C = 20, DU = 21 and GU = 14) were included in the study. Gastric mucosal samples were obtained either by endoscopic biopsy (4.6 +/- 0.2 milligrams of weight) or operation (52.3 +/- 3.8 milligrams of weight). RIA was performed after a modified Arimura's method and results were expressed as nanograms per milligram of tissue plus or minus standard error of the mean. Chromatographic analysis of gastric mucosal extracts was performed on a Sephadex G-25 fine column. A great interindividual variation in SLI levels was observed (a range of 0.02 to 5.30 nanograms per milligram of weight). The mean SLI concentrations were: C (SLI-a, 2.55 +/- 0.45, SLI-c, 0.99 +/- 0.46 and SLI-f, 1.03 +/- 0.21); DU (SLI-a, 0.48 +/- 0.16, SLI-c, 0.43 +/- 0.13, and SLI-f, 0.58 +/- 0.12), and GU (SLI-a, 1.10 +/- 0.25, SLI-c, 0.40 +/- 0.10, and SLI-f, 0.81 +/- 0.24). Significantly greater amounts of SLI contents were found in the antrum of control patients as compared with those found in the corpus or fundus (p less than 0.05 and p less than 0.01, respectively). SLI-a levels were lower in peptic ulcer patients (DU, p less than 0.001 and GU, p less than 0.05) than in control patients. There was also a significant difference between SLI-a levels in DU versus GU patients (p less than 0.05). No significant differences were found in SLI-c and SLI-f contents in all three groups studied. In conclusion, these results suggest that decreased SS levels in antral gastric mucosa could be the alteration underlying the various physiopathologic mechanisms involved in the development of peptic ulcer disease.

[Biochemical complications of experimental vesico-sigmoidostomy]

Three experimental models of vesico-sigmoidostomy are studied (model-1, end to side V-S plus urethral ligation, model-2, end to end V-S, in "Y of Rous" plus urethral ligation and model-3, vesico-sigmoidoplasty), with aim of reproducing chemical imbalance observed in human subjects with ureterosigmoidostomy. Authors have evaluated clinical biochemical (serum acido-base balance, Cl, Na+, K+, BUN, creatinine, ammonia and albumin), and histologic variables in the first, third and fifth month after operation in 225 rats. Animal of model-1 presented more frequently than model-2 and model-3, alterations (hyperchloraemic acidosis, uraemia, hyperammonemia and hypoalbumin) as well as affectation of upper urinary system for acute or chronic pyelonephritis.

Antral gastrin-producing G-cells and somatostatin-producing D-cells in peptic ulcer

The number of G cells and D cells per area unit and the G cell/D cell ratio was studied in control subjects and patients with duodenal or gastric ulcer. A great inter-individual variation in the population density of both types of cells was observed in the three groups studied. G cell density was significantly decreased in both duodenal and gastric ulcer patients, when compared with controls; whereas no difference in G cell density was seen between duodenal ulcer patients and gastric ulcer patients. However, D cell density was significantly decreased in duodenal ulcer patients when compared with control subjects and gastric ulcer patients. In this latter group, D cell density was also lower than in control subjects. A significant positive linear correlation between G cell number and D cell number was found in the three groups studied. The G cell/D cell ratio was significantly increased in duodenal and gastric ulcer patients when compared with controls. This was mainly due to a decrease in D cell numbers. It is concluded that a local deficit in antral D cells in patients with peptic ulcer may favor the pathogenesis of ulcer disease.

Acetaminophen-induced fulminant hepatic failure in dogs

Results concerning morphological and biochemical changes following intravenous administration of different doses of acetaminophen in dogs are reported. Acetaminophen infusion, as a parenteral solution (500 mg per kg per 90 min), produced fulminant hepatitis characterized by a good correlation between Portmann's grade of lesion and percentage of necrosis. All animals died within 76 hr after intoxication. Analysis of biochemical parameters revealed positive correlation between serum bilirubin levels and severity of the hepatic lesion. The experimental model of acetaminophen-induced hepatotoxicity is proposed as a model for evaluation of the therapeutic efficacy of new medical and surgical procedures.

Charcot arthropathy secondary to amyloid neuropathy

Neuropathic (Charcot) ankle joints developed in a 50-year-old patient with end-stage renal disease from primary, nonfamilial amyloidosis. Sensory neuropathy in the legs had been noted three years before the onset of uremia and had porgressed. Sural nerve, but not synovial biopsy specimen, showed amyloid in and around arteriolar walls by light and electron microscopy. Since Charcot joints are only rarely associated with amyloid neuropathy, it is possible that uremic neuritis, or prolonged survival by dialysis, contributed to progression of the neuropathy, allowing subsequent joint degeneration.

[Pharmacological reactivity in cricetus aureus uterus (author's transl)]

The motility of the isolated Cricetus auratus uterus was studied and compared to that of other species. Oxitocyn, epinephrine, norepinephrine, histamine, 5-hydroxy-tryptamine and acetylcholine were used as spasmogen agents. There was not contractil response with epinephrine or nor-epinephrine. Histamine reduced basal tonus. There was contraction with acetylcholine, oxytocin and 5-hydroxy-tryptamine. Cricetus auratus uterus appeared more sensitive when the contraction was registered by the isometric method. No taquifilaxy was produced by 5-hydroxy-tryptamine, as opposed to such effect in rat uterus. The Cricetus auratus uterus has, therefore, shown similar reactivity to that of rat, but different from rabbit and guinea-pig.