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S Vas

Publications and source records attributed to S Vas.

At least 37 records · Page 2Linked to original sources
PubMed1989

HLA class I-related impairment in IL-2 production and lymphocyte response to microbial antigens in reactive arthritis.

The contribution of certain Gram-negative bacteria and host HLA class I Ag to the development of reactive arthritis (ReA)3 has strong epidemiologic support but the pathogenesis of the arthritis is unknown. An outbreak of Salmonella typhimurium afforded the opportunity to compare the immune response to the organism between those who developed ReA (ReA+, n = 11) with those who did not (ReA-, n = 12). Of the 11 ReA+ patients, 4 were B27-positive and 6 were B7-positive; of the ReA- patients none was B27- or B7-positive. The causative pathogen S. typhimurium phage 22 was used to examine PBL proliferation by [3H]thymidine incorporation. Impairment in lymphocyte response to S. typhimurium in ReA+ compared with ReA- was demonstrated by: i) lower stimulation index (1.9 +/- 0.3 for ReA+, 5.7 +/- 0.6 for ReA-, p less than 0.01); ii) lower in vitro Ig production; and iii) lower Ag-induced IL-2 production. Mixing experiments did not demonstrate a soluble suppressor factor in ReA+ supernatants. Thus, after infection with S. typhimurium there is an impairment in cellular immunity that has correlates in immunogenetic and clinical features of the infected population.

Antibodies, Bacterial↗
PubMed1989

Splenic abscess and peritonitis in a continuous ambulatory peritoneal dialysis (CAPD) patient.

A 26-year-old female was on continuous ambulatory peritoneal dialysis (CAPD) because of diabetic end-stage renal failure. She developed an acute peritonitis that relapsed repeatedly despite appropriate antibiotic treatment. Investigations showed the presence of a splenic abscess, and splenectomy and peritoneal cannula removal were required. The patient died of myocardial infarction two weeks postoperatively. This is the first recorded case of peritonitis secondary to splenic abscess in a CAPD patient. Autopsy findings suggest that the abscess developed from infection of a splenic infarct.

Abscess↗
PubMed1986

Diagnostic significance of anti-HBcIgM prevalence related to symptoms in Canadian patients acutely or chronically infected with hepatitis B virus.

A total of 362 sera from 295 Canadian patients were examined for HBsAg, anti-HBs, anti-HBc, anti-HBcIgM, HBeAg, and anti-HBe using commercial immunoassays. Serial samples from 70 acutely infected patients demonstrated that anti-HBcIgM may detect 10% more positives than HBsAg within 4 months after the onset of clinical symptoms, and all except two were negative for anti-HBcIgM after the fourth month. None of 66 asymptomatic (HBeAg rate 18.2%) and two of 14 (14.3%) symptomatic (HBeAg rate 64.3%) carriers of HBsAg were positive for anti-HBcIgM (P = 0.029). Elevated marker responses were measured in two symptomatic carriers for a 20-month period. Anti-HBcIgM was not detected in either 100 asymptomatic patients positive for total anti-HBc, negative for HBsAg and negative for or possessing low levels of anti-HBs, 25 patients with liver disorders not caused by HBV, or 20 healthy milk donors. In diagnostic laboratory practice this anti-HBcIgM test may be useful in the following situations: to supplement HBsAg testing, providing a theoretical 10% increase in positives within 4 months following onset of acute viral hepatitis; to replace testing for anti-HBc and anti-HBs in symptomatic HBsAg-negative patients; to confirm whether a patient is experiencing acute or chronic HBV infection or symptoms superimposed upon asymptomatic HBsAg carriage by another cause, such as nonA-nonB viral hepatitis.

Acute Disease↗
PubMed1986

Propionibacteria isolates and asymptomatic infections of the peritoneal effluent in CAPD patients.

During the past two years our laboratory has isolated Propionibacterium-an anaerobic Gram-positive rod-on 40 occasions from the drainage fluid of 25 patients on CAPD and eight on IPD. Most patients had no symptoms and the fluid was sent for culture after treatment of peritonitis, during training period, and occasionally because it was cloudy. No association was found with patients' age, length on dialysis, or previous peritonitis episodes. The only statistically significant association (P = 0.033) was with recent (less than 30 days) catheter insertion. Patients with Propionibacterium as the only organism in their dialysis fluid had normal leucocyte count in the effluent, minimal or no symptoms, and received no treatment. In order to establish the frequency of positive cultures of asymptomatic patients, we cultured 95 dialysate effluents from 33 asymptomatic CAPD patients. Cultures were observed for 4 weeks. We found seven positive fluids (7.4%) in four patients (12%), aerobic sporeformer (2), Staphylococcus epidermidis (2) and Streptococcus viridans (1). The mean time to grow was 18.6 days. In conclusion, effluents from asymptomatic CAPD patients may contain bacteria. The organisms are commensals requiring prolonged incubation to grow. Propionibacterium isolated from peritoneal effluent of patients with minimal or no symptoms does not require treatment. These findings suggest that errors in the technique of CAPD are not rare but when the number of organisms is small and the organism has low virulence, peritonitis does not occur.

Adult↗
PubMed1985

The reduction in the peritonitis rate among high-risk CAPD patients with the use of the Oreopoulos-Zellerman connector.

We have described a prospective controlled study of the Oreopoulos-Zellerman peritoneal dialysis connection system which is based on the principle of chemical sterilization of the connector between each dialysis exchange. This system, in a short-term study of 27 high-risk patients, has resulted in a fourfold difference in the peritonitis rate between the concurrent control group (1/8.8 patient months) and the O-Z group (1/35.7 patient months). The probability of developing peritonitis by 6 mos was 0.15 using the O-Z connector and 0.46 in the control group.

Adult↗
PubMed1983

Pulmonary disposition of tobramycin.

Each antibiotic has a characteristic penetration into respiratory secretions, influenced by serum concentration, protein binding, transport systems, and the presence of infection. Whereas previous studies have used only bronchial secretions and blood, in the present study, blood, bronchial secretions, and bronchoalveolar lavage (BAL) fluid were analyzed for tobramycin levels. In 10 studies in 9 patients, serum levels were significantly related to BAL fluid levels (r = 0.8, p less than 0.01) when both were expressed as a function of creatinine (mean BAL level +/- SD = 144 +/- 124 micrograms/mg creatinine; serum level, 293 +/- 216 micrograms/mg creatinine). The level of drug penetration in BAL fluid, expressed by the slope of the relationship between blood and fluid, was 0.5. The penetration of tobramycin into bronchial secretions ranged from 0 to 1.4 micrograms/ml, the ratio of secretions to serum being 0.2 (r = 0.68; p less than 0.05). It is concluded that the disposition of tobramycin in bronchial secretions and BAL fluid differ. Thus, sampling both fluids offers a more suitable method to study antibiotic pharmacokinetics in bronchi and alveoli.

Adult↗
PubMed1982

Continuous ambulatory peritoneal dialysis in diabetics with end-stage renal disease.

Twenty diabetics with end-stage renal disease who had never previously received dialysis treatment were treated with continuous ambulatory peritoneal dialysis for periods of two to 36 months (average, 14.5). Intraperitoneal administration of insulin achieved good control of blood sugar. Even though creatinine clearance decreased significantly (P = 0.001), control of blood urea nitrogen and serum creatinine was adequate. Hemoglobin and serum albumin levels increased significantly (P = 0.005 and 0.04, respectively). Similarly, there was a significant increase in serum triglycerides and alkaline phosphatase (P = 0.02 and 0.05). Blood pressure became normal without medications in all but one of the patients. Retinopathy, neuropathy, and osteodystrophy remained unchanged. Peritonitis developed once in every 20.6 patient-months--a rate similar to that observed in nondiabetics. The calculated survival rate was 93 per cent at one year; the calculated rate of continuation on ambulatory peritoneal dialysis was 87 per cent. We conclude that continuous ambulatory dialysis with intraperitoneal administration of insulin is a good alternative treatment for diabetics with end-stage renal disease.

Adult↗
PubMed1982

Experimental model for studies of continuous peritoneal'dialysis in uremic rabbits.

In this paper we describe an experimental model designed for studies of continuous ambulatory peritoneal dialysis (CAPD) in uremic rabbits. We preferred the study of uremic animals because it is not known whether peritoneal membrane differs between normal and uremic animals. Animals made uremic after bilateral nephrectomy could not survive on dialysis. Instead, partial nephrectomy of one kidney and partial (5/6) destruction of the cortex of the remaining kidney by electrocauterization provided a simple and reproducible model. CAPD resulted in adequate control of uremia but the animals showed significant decreases in total plasma proteins and weight. This model is suitable for studies of the metabolic complications of CAPD.

Animals↗
PubMedDate not supplied

High prevalence of hyperparathyroidism among peritoneal dialysis patients: a review of 176 patients.

OBJECTIVES: Parathyroid dysfunction continues to produce significant morbidity in dialysis patients. Since the introduction of low calcium dialysate for peritoneal dialysis (PD), no large studies have been done to determine the prevalence of parathyroid dysfunction in these patients. This study was done to assess the prevalence of parathyroid disease in the PD population and to determine the risk factors associated with this dysfunction. DESIGN: We analyzed data on 176 patients who received PD at a single center between August 1998 and February 1999. Clinical data, laboratory variables related to parathyroid function, and data pertaining to dialysis treatment and weekly drug dosing were obtained for each patient on two different occasions, approximately 3 months apart. Variables predictive of the development of parathyroid dysfunction were calculated by univariate and multivariate logistic regression analysis. RESULTS: Two-thirds of the patients surveyed had an abnormal intact parathyroid hormone (iPTH) level: 47% had an iPTH level more than three times normal, the mean was 54.6+/-35.4 pmol/L; 23% had an iPTH value below the upper limit of normal, here the mean was 3.6+/-1.8 pmol/L. Diabetic patients had lower iPTH levels (22.2+/-28.4 pmol/L) than nondiabetics (33.9+/-34.8 pmol/L) (p = 0.02). On multivariate regression analysis, we found that age, duration of dialysis, Kt/V, serum bicarbonate, and serum ionized calcium levels did not significantly affect parathyroid function. Hyperphosphatemia was the only factor that was associated with the development of secondary hyperparathyroidism in this study population (p = 0.029). CONCLUSION: There is a high prevalence of hyperparathyroidism in the current PD population. Phosphate control is suboptimal and hyperphosphatemia is an independent risk factor for the development of hyperparathyroidism.

Adult↗