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Biomedical subjects

D G Oreopoulos

Publications and source records attributed to D G Oreopoulos.

At least 163 records · Page 9Linked to original sources
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↗
PubMed1989

Permeability of different parts of the peritoneal mesothelium to solutes: an in vitro study.

The authors studied the in vitro permeability of different fragments of the rabbit's peritoneum to urea, inulin, horseradish peroxidase, and ferritin. Parietal peritoneum has a lower permeability to middle and large molecules than visceral peritoneum. In addition the local anesthetic, bupivacaine had a different effect on the mesothelial permeability of visceral peritoneum than on that of parietal peritoneum.

Animals↗
PubMed1989

Effect of various factors on peritoneal lymphatic flow in rabbits.

Peritoneal lymphatic flow in normal and uremic rabbits was measured by estimation of the disappearance of the radiolabelled 131I-albumin from the peritoneal cavity. The results show that lymph flow rate from the peritoneal cavity is not steady and depends on dialysate volume, its tonicity, and protein content. During peritoneal dialysis, peritoneal lymphatic flow is lower at the beginning of an exchange. Peritoneal lymphatic drainage is higher in uremic rabbits compared to normal controls.

Albumins↗
PubMed1989

Oral lecithin improves ultrafiltration in patients on peritoneal dialysis.

Three patients on peritoneal dialysis (two on continuous ambulatory and one on intermittent) with severe ultrafiltration failure were treated with 2 capsules of Lecithin three times a day (containing of 1.08 g of phosphatidylcholine). Their ultrafiltration improved significantly to the point that their edema improved and were able to continue on peritoneal dialysis with fewer daily hypertonic exchange.

Administration, Oral↗
PubMed1989

Changes in peritoneal membrane transport rates in patients on long term CAPD.

Peritoneal equilibration tests (PET's) are a simple means of monitoring peritoneal membrane function in C.A.P.D. patients. Findings on initial testing have been proposed as having prognostic value for a patient's course on peritoneal dialysis. 177 serial P.E.T.'s were performed in 49 patients at six monthly intervals using a 2 litre 4.25% dextrose exchange and a four hour dwell and equilibration ratios were calculated for urea (D/P U), creatinine (D/P C) and glucose (D/Do G). Alterations in equilibration ratios with time were not significant in the group as a whole. However, a subgroup of 12 patients was identified in whom there were significant increases in D/P U (p .02) and in D/P C (p .003) and decreases in D/Do G (p .025) between zero and 18 months. A subgroup of five patients in whom D/P U decreased significantly (p .05) was also identified. These subgroups did not differ significantly in clinical characteristics although peritonitis was more frequent in the group with increasing transport. As results of P.E.T.'s alter with time in many patients prognostication based on initial values only may not be valid.

Adolescent↗
PubMed1989

Oxalate bone disease--an emerging form of renal osteodystrophy.

Rosette-like arrays of highly birefringent calcium oxalate crystals are commonly seen in the marrow space of bone biopsy specimens taken from patients with primary hyperoxaluria, particularly if complicated by renal failure. Similar deposits have been described in chronic hemodialysis patients with secondary forms of oxalosis. Large multinucleated histiocytes may be seen surrounding these crystal deposits. Many of these cells are histologically indistinguishable from osteoclasts. We present a patient in whom this histiocytic reaction appeared to be of sufficient magnitude to stimulate bone resorption and to cause severe osteodystrophy. This observation, and those of other investigators reviewed in the discussion, suggest that oxalate deposition within bone may contribute to the pathogenesis of uremic osteodystrophy in chronic renal failure patients with primary or secondary types of oxalosis.

Adult↗
PubMed1989

Subcapsular steatonecrosis in response to peritoneal insulin delivery: a clue to the pathogenesis of steatonecrosis in obesity.

Hepatic steatosis and steatonecrosis occur in nonalcoholic individuals, usually in a setting of obesity, type II diabetes mellitus, and after jejunoileal bypass. We propose an hypothesis for the pathogenesis of these hepatic lesions based on an observation in peritoneal dialysis patients. Hepatic histology was examined at autopsy in 11 patients with type I diabetes mellitus and renal failure who had received i.p. insulin in conjunction with continuous ambulatory peritoneal dialysis (CAPD). Steatosis in a unique subcapsular distribution occurred in 10 of 11 patients treated with i.p. insulin and in 0 of 9 controls receiving CAPD without insulin. Three of the 11 had steatonecrosis, 2 of whom had Mallory bodies. We suggest that insulin has an important role in the pathogenesis of steatosis and steatonecrosis. In CAPD patients the lesions occurred only under the capsule where concentrations of insulin are high secondary to its i.p. administration. In obese patients the lesions occur throughout the liver where insulin concentrations are high because of elevated levels in the portal vein. Free fatty acids (FFA) are oxidized in the liver by a pathway that is blocked by insulin. In the presence of insulin, FFA are preferentially esterified into triglycerides which accumulate in large quantities leading to steatosis; small amounts of FFA escaping local control may lead to membrane injury and steatonecrosis. Steatosis and/or steatonecrosis will occur when there is insulin secretion sufficient to block FFA oxidation but not sufficient to block FFA mobilization from adipose tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Control of hyperoxaluria with large doses of pyridoxine in patients with kidney stones.

Pyridoxine in doses of 250-500 mg daily by mouth was administered to 12 patients suffering from recurrent calcium oxalate renal calculi and idiopathic hyperoxaluria. This therapy decreased urinary oxalate excretion significantly (p less than 0.025) during up to 18 months of treatment. In that period eight patients showed no evidence of active stone disease; three showed slight increase in the size of their old stone(s) and one patient formed one new stone. None of these patients developed any significant complications of the therapy. These findings support the view that pyridoxine in pharmacological doses is useful in the control of elevated urinary oxalate excretion in patients with recurrent renal oxalate calculi.

Adult↗
PubMed1987

Acquired cystic disease of the kidney in association with chronic ambulatory peritoneal dialysis.

A combined necropsy and ultrasound study in patients with end-stage renal disease treated exclusively by peritoneal dialysis revealed acquired cystic disease of the kidney (ACDK) in five of 15 necropsies and in one of seven sonograms from living patients. Two benign microscopic adenomas were also found in the first group of patients. No malignant renal tumors or hemorrhagic complications were detected. The cause of the cyst formation is clearly related to chronic renal failure rather than dialysis per se, as one patient had cysts prior to CAPD and seven of 41 patients with end-stage renal disease in the predialysis era were found to have renal cysts on postmortem examination. This study shows that ACDK is not uncommon in patients with chronic renal failure treated by chronic ambulatory peritoneal dialysis.

Adenoma↗
PubMed1987

Serum magnesium level and arterial calcification in end-stage renal disease.

In this paper we examine the relationship of serum levels of Ca, P, Ca X P, P/Mg, Ca X P/Mg, alkaline phosphatase, and iPTH to the development or regression of peripheral arterial calcifications (AC) in 44 patients with end-stage renal disease being treated by continuous ambulatory peritoneal dialysis (CAPD). The average follow-up time of this longitudinal study was 27 months (range 6-67 months). The patients were divided into two groups: Group A, those showing one or more increases of AC; and Group B, patients in whom AC either did not develop or decreased during the follow-up. There was no significant difference in serum Ca, P, Ca X P, alkaline phosphatase of iPTH between the two groups. However, serum Mg was significantly lower in Group A than in Group B (2.69 +/- 0.52 and 3.02 +/- 0.51 mg/dl, respectively, P less than 0.001), while the ratios P/Mg and Ca X P/Mg were significantly higher. Our observations suggest that in end-stage renal disease hypermagnesemia may retard the development of arterial calcifications.

Adult↗
PubMed1986

Periosteal resorption and periosteal neostosis: comparison of normal subjects and renal failure patients on chronic ambulatory peritoneal dialysis using MOP-3 image analysis system and a grading method.

This is the first known attempt to quantitate periosteal resorption (PR) and perisoteal neostosis (PN) by a semi-automatic image analysis system (Zeiss MOP-3). The normal ranges and errors for PR were found to be similar to those of a previous study using a measuring magnifier. The findings in chronic renal failure patients showed that MOP-3 measurements were actually diagnostically slightly less sensitive than the results by a simple grading method. Comparison with plasma-immunoreactive parathyroid hormone (iPTH) concentrations showed that while the latter had a higher sensitivity for detection of hyperparathyroidism, the radiologic parameters nevertheless showed abnormal PR in 12% of the observations where iPTH was normal. Both PR and PN correlated significantly with iPTH (r = 0.55 and 0.30 respectively, P less than 0.01).

Adult↗
PubMed1986

Morphology, progression, and regression of arterial and periarterial calcifications in patients with end-stage renal disease.

The appearance of arterial calcifications over time was studied radiographically in 143 patients with end-stage renal disease. Of these, 85 patients had only slight calcifications; 58 had the well-known, linear, pipe stem-like arterial calcifications. In 44 of the 58, small nodular calcifications were noted, often external to the linear calcifications. Nine patients had larger periarterial calcifications, which have not been previously described to our knowledge. Arterial calcifications progressed in 82 of 143 patients (57%) and regressed in 19 (13%). During progression, thickening of the linear calcifications was often observed, and in ten patients this caused definite luminal narrowing. From 1976 to 1984, five of 71 patients (7%) required amputations; all five had marked arterial calcifications. Better controlled clinical studies are indicated to detect factors that may prevent the progression and promote the regression of arterial calcifications.

Adult↗
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↗