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Biomedical subjects

J Rubin

Publications and source records attributed to J Rubin.

At least 307 records · Page 17Linked to original sources
PubMed1980

Renal biopsy in acute allograft rejection. Significance of moderate vascular lesions in long-term graft survival.

55 renal allograft biopsies obtained during acute rejection episodes resistant to standard antirejection therapy in 36 renal transplant recipients were reviewed and the findings correlated with long-term graft prognosis. 20 patients demonstrated moderate vascular pathology (group A), while 16 patients demonstrated changes consistent with pure cell-mediated rejection wit no vascular lesions (group B). Groups were similar with respect to age range, duration of haemodialysis, sex and antigen match. Of patients with vascular changes, 11 had arterial changes, 9 had arteriolar changes and 6 had arterial and arteriolar changes. The cumulative graft survival for group A was significantly less than that for group B at all post-transplantation intervals up to 24 months (p < 0.001).

Adult↗
PubMed1980

An evaluation of two schedules of VP-16 and adriamycin in patients with advanced breast cancer.

A phase II study utilizing VP-16 and adriamycin in a randomized fashion tested the concept of synchronization of the drugs in treatment of metastatic breast cancer. Although there was a trend in median survival following the synchronized schedule, there was no significant difference in survival or progression-free intervals. The concept of synchronization was not established.

Bone Marrow↗
PubMed1980

A survey of mental health policy options.

A confusing array of options to reform mental health care is now under consideration by policymakers. To clarify the implications of these options, five categories of actions are distinguished. These reforms are: federal program change, litigation, state commitment statute reform, alterations in private market variables and efforts to change attitudes. The overlaps among them are discussed as is the importance of knowing more about the relative effectiveness of each action. Wide-ranging reforms have been underway on an ad hoc basis for sometime. This paper argues that before further major initiatives are undertaken, the establishment of a better information base and an improved understanding of the interrelationships of the numerous mental health policies are necessary.

Attitude to Health↗
PubMed1980

Peritonitis during continuous ambulatory peritoneal dialysis.

We initiated a therapeutic program of continuous ambulatory peritoneal dialysis for patients with chronic renal failure. Our program resulted in many episodes of peritonitis arising from contamination due to the technical aspects of the procedure. Microbiologic evaluation showed that 73% of 97 episodes were culture positive, with gram-positive organisms causing most of the cases, especially early in dialysis. Gram-negative rods tended to occur later. Gram stains of dialysate effluent resulted in a disappointingly low yield of only 9% positivity. Cell counts were a dependable indicator of the presence of peritoneal inflammation and also of therapeutic success. Most patients responded well to intraperitoneal cephalothin, 125 mg/L for 10 to 14 d. The occurrence of peritonitis resulted in 0.93 years of hospitalization during the total of 15.45 patient-years on dialysis, which essentially negated the financial advantages of this method of treatment of chronic renal failure. For this to be a successful mode of therapy, advances in the prevention of peritonitis must be made.

Adult↗
PubMed1980

Continuous ambulatory peritoneal dialysis: three-year experience at one center.

Three years of clinical experience with continuous ambulatory peritoneal dialysis are summarized. Serum urea nitrogen, creatinine, hematocrit, nerve conduction velocity, calcium, inorganic phosphorus, serum proteins, and electrolytes have been maintained in acceptable ranges. Peritonitis, although reduced in incidence because of solutions in plastic bags and a new adapter, is still a problem. Excessive carbohydrate absorption, obesity, and high serum triglyceride concentrations may be long-term problems in some patients.

Adolescent↗
PubMed1980

New directions in peritoneal dialysis concepts and applications.

A limited number of peritoneal capillaries involved in solute exchange during peritoneal dialysis and inaccessible stagnant fluid films within the peritoneal interstitium may account for most resistance to solute transport during peritoneal dialysis. The control of small solute concentrations in blood by intermittent peritoneal dialysis will probably always require 30 to 40 hr/week of treatment even with the most rapid cycling devices. Increased understanding of factors that effect the microcirculation of the peritoneum may allow manipulation of protein losses and optimization of the long-term health of the peritoneum but will probably have little impact on the efficiency of small solute transport. CAPD accepts peritoneal dialysis as a low-efficiency system in terms of small solute clearances and yet yields similar weekly clearances to hemodialysis for small solutes by utilizing continuous dialysis. Large solute clearances with CAPD markedly exceed weekly clearances with hemodialysis.

Ambulatory Care↗
PubMed1980

In vitro simulations of peritoneal dialysis. A technique for demonstrating limitations on solute clearances due to stagnant fluid films and poor mixing.

Stagnant fluid films in the peritoneal interstitium and peritoneal cavity may explain low clearances during peritoneal dialysis. Various peritoneal dialysis techniques may influence clearances by enhancing mixing. However, such techniques also may change fresh fluid replacement rates and/or after peritoneal membrane transport characteristics secondary to mechanically, osmotically, or chemically induced changes in the peritoneium and its vasculature. Various techniques were evaluated in an in vitro simulation of peritoneal dialysis where membrane transport characteristics would not change and the impact of better mixing alone could be assessed. Only very vigorous agitation of fluid appears to influence stagnant fluid film resistances under the conditions of these studies. In actual peritoneal dialysis, fluid film resistances are probably even less likely to be influenced by existing techniques.

Ascitic Fluid↗
PubMed1979

Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial.

One hundred and fifty patients with advanced cancer participated in a controlled double-blind study to evaluate the effects of high-dose vitamin C on symptoms and survival. Patients were divided randomly into a group that received vitamin C (10 g per day) and one that received a comparably flavored lactose placebo. Sixty evaluable patients received vitamin C and 63 received a placebo. Both groups were similar in age, sex, site of primary tumor, performance score, tumor grade and previous chemotherapy. The two groups showed no appreciable difference in changes in symptoms, performance status, appetite or weight. The median survival for all patients was about seven weeks, and the survival curves essentially overlapped. In this selected group of patients, we were unable to show a therapeutic benefit of high-dose vitamin C treatment.

Aged↗
PubMed1979

Cardiovascular changes during general anaesthesia: for dental surgery. A prospective study of five different anaesthetic techniques.

A prospective study of 79 fit young adults who underwent oral dental surgery was undertaken with five different anaesthetic techniques. Anaesthesia was commenced with methohexitone or flunitrazepam, muscle relaxants, and cuffed nasal intubation, and anaesthesia was maintained with 50% nitrous oxide, 50% oxygen, halothane or fentanyl with or without intermittent positive pressure ventilation (IPPV). Six of the 33 patients who received methohexitone and halothane developed dangerous dysrhythmias. Flunitrazepam, IPPV, adequate analgesia and anaesthesia provide maximum cardiovascular stability.

Adult↗
PubMed1979

VP-16, cyclophosphamide, adriamycin and cis-platinum (V:CAP-I) in patients with metastatic adenocarcinoma of the lung.

In an attempt to improve upon the 42% regression rate of the CAP-I regimen in patients with advanced adenocarcinoma of the lung, VP-16 was added to that regimen. VP-16, as a single agent, had a response rate of 12.5% (3/24) In a similar group of patients. The new regimen, V:CAP-I, had a tumor regression rate of 35% (7/20) and an estimated median survival of 171 days. Hence, we were unable to conclude that the addition of VP-16 to the CAP-I regimen statistically improved the regression rate of the CAP-I regimen.

Adenocarcinoma↗
PubMed1979

A phase I study of chlorozotocin (NSC 178248).

Chlorozotocin was administered by rapid intravenous infusion to 35 patients with advanced cancer on either single-day of five-consecutive-day schedules. Total doses per course ranged from 12.5 to 200 mg/m2. On either administration schedule, dose limiting toxicities were thrombocytopenia and leukopenia at total doses of 150 mg/m2 to 200 mg/m2. Repetitive courses of drug may produce progressive impairment of renal and bone marrow function. Nausea and vomiting were infrequent and mild without definite relationship to dose. Minor reversible nondose related increases in SGOT and in serum creatinine occurred at all doses on both schedules. The plasma half-life of intact N-nitroso groups averaged 9.5 minutes after rapid intravenous administration of doses up to 40 mg/m2 and 12.5 minutes after doses of 150 or 200 mg/m2. No differences between plasma half-lives were seen between identical doses given on the first and fifth days of the five-day schedule. Objective tumor regression was noted in one patient with bronchogenic large cell carcinoma and one patient with metastatic melanoma.

Adult↗
PubMed1979

Follow-up of peritoneal clearances in patients undergoing continuous ambulatory peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) might result in peritoneal membrane changes. First, CAPD exposes essentially continuously the peritoneum to peritoneal dialysis solutions. Such solutions differ from the usual extracellular fluid bathing peritoneal tissues. Second, this technique may be complicated by an increased frequency of peritonitis when compared to intermittent peritoneal dialysis. We undertook a prospective study of patients undergoing CAPD to determine if there were decreases in peritoneal clearances and if the peritoneal microcirculation maintained its responsiveness to nitroprusside. Peritoneal transport, as assessed by the clearances of urea, creatinine, inulin, and dialysate protein concentration, with and without nitroprusside addition in the dialysis solution, is unchanged in patients undergoing CAPD for up to 1 year, despite frequent episodes of peritonitis.

Adult↗
PubMed1979

Microvascular and clinical effects of altered peritoneal dialysis solutions.

Blood flow in the peritoneum is one of the more important factors governing the efficiency of peritoneal dialysis. Yet there have been no previous studies which relate alterations and control of the peritoneal microcirculation to dialysis efficiency. Thus, we used closed-circuit television microscopy to quantitative the in vivo response (changes in diameter) to dialysis solutions of the small arteries on the mesothelial surface of the rat cecum and arterioles of the rat cremaster muscle. These responses were correlated wiht solute clearances from multiple peritoneal dialysis performed in humans. In the cremaster, a transient constriction was followed by a prolonged dilation. pH adjustments of the dialysis solution from 5.6 to 7.4 had no effect on the microvascular response and no effect on solute clearances during human peritoneal dialysis. In the cecum, dialysis solution caused a prolonged dilation which reached a maximum in about 10 min. Since dilation appears to be an important determinant of solute clearances during human peritoneal dialysis, the effects of a vasodilator, sodium nitroprusside, were determined. Sodium nitroprusside decreased the time to maximal dilation, which correlated clinically with an increased solute clearance during exchanges with this drug. Since nitroprusside increased clearances of the larger molecular weight solutes proportionally more than the smaller molecular weight solutes did, we hypothesize that nitroprusside increases solute clearances by both a vasodilatory effect and by an effect on vascular membrane permeability and area for solute exchange.

Animals↗
PubMed1979

Osmotic ultrafiltration with dextran sodium sulfate potential for use in peritoneal dialysis.

Dextran sodium sulfate was evaluated in vitro as a potential non-absorbable osmotic agent for peritoneal dialysis. It was compared to poly(sodium acrylate) which has been shown previously to be effective in rats, but probably toxic. Dextran sodium sulfate induced osmotic ultrafiltration rates as high as 20 ml/min in water but only 2 ml/min in solution containing non-polymer electrolytes presumably because of Gibbs-Donnan effects. Compared to acrylate the dextran polymer has less sodium per gram, lower osmotic activity of polymer sodium, and yields less ultrafiltration at given transmembrane osmolalities. A non-toxic polymer more like acrylate would seem more promising as an osmotic agent for peritoneal dialysis.

Acrylates↗