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Biomedical subjects

J Rubin

Publications and source records attributed to J Rubin.

At least 163 records · Page 9Linked to original sources
PubMed1990

Aural irrigation with water: a potential pathogenic mechanism for inducing malignant external otitis?

We hypothesized that the forcible introduction of water containing Pseudomonas aeruginosa into the ear canal of a susceptible host (an elderly diabetic with cutaneous hypoperfusion secondary to microangiopathy) was the inciting factor in the development of malignant external otitis. Tap water irrigation of the ears by a physician preceded the onset of symptoms in 61.5% (8/13) of cases of malignant external otitis. Two control subjects with known diabetes mellitus were matched for each patient by sex and age. Both groups were questioned on the nature and degree of aural water exposure, as well as history of ear disease. There were no significant differences between 13 patients and 26 control subjects for presence of ear disease (hearing loss, chronic infection, prior operations), swimming, showering, bathing, frequency of ear cleaning, or method of ear cleaning (washcloth, cotton applicator). Patients with malignant external otitis had a statistically significant higher incidence of aural irrigation with tap water when compared with control subjects. We suggest that a substantial number of cases of malignant external otitis may be iatrogenic.

Aged↗
PubMed1990

Stomal recurrence after laryngectomy: interrelated risk factor study.

This study was designed to identify pathogenic factors in recurrent carcinoma at the tracheal stoma. The charts of 444 patients with laryngeal cancer who were treated surgically between 1976 and 1988 revealed stomal recurrence in 15 (3.4%). Eighty percent of the patients with stomal recurrence had tumors in the subglottis. In comparison to patients with different sites involved this was significant (p less than 0.001). Other variables examined and analyzed included primary stage, previous treatment, neck pathologic status, neck treatment, age, sex, postoperative adjunctive therapy, and timing of tracheotomy. Tumor involvement of the subglottis is the single most important variable in stomal recurrence of carcinoma. Previous conservation laryngeal surgery and preoperative/emergency tracheotomy are not related to stomal recurrence of carcinoma. Mean length of survival for patients with stomal recurrence of carcinoma in our series was 8.9 months. Two patients were successfully treated with extensive surgical resection. The dismal prognosis of stomal recurrence of carcinoma suggests that management of this condition should focus on prevention. Treatment of patients with tumors of the subglottis should include attention to the paratracheal region and superior mediastinum, in conjunction with laryngectomy immediately after initial diagnosis.

Adult↗
PubMed1990

Interferon-gamma inhibits 1,25-dihydroxyvitamin D3-stimulated synthesis of bone GLA protein in rat osteosarcoma cells by a pretranslational mechanism.

Interferon-gamma (IFN) is produced by lymphocytes in areas of inflammation and connective tissue destruction. IFN inhibits collagen and DNA synthesis in cultured rat long bones and osteoblastic ROS 17/2.8 cells, suggesting that the periarticular loss of bone that occurs in inflammatory joint diseases may be due to IFN inhibition of bone formation. Since serum levels of bone gla protein (BGP) have been correlated with the bone formation rate, we studied the effect of IFN on production of this osteoblast-specific protein and steady state BGP messenger RNA (mRNA) levels in ROS 17/2.8 cells. RIA of BGP was done using an antibody raised against rat BGP peptide. BGP synthesis was stimulated with 10(-8) M 1,25-dihydroxyvitamin D3 24 h before and continuously after addition of recombinant rat IFN. IFN (100 U/ml) inhibited BGP secretion 52%, 78%, and 70% in the first, second, and third 24 h periods after IFN treatment, compared to control cells cultured with 1,25-dihydroxyvitamin D3 alone. The ED50 for IFN inhibition of BGP production was 3.3 U/ml (0.29 nM). Pulse labeling with [14C]leucine or [3H]proline during the last 4 h of culture revealed that IFN (3-100 U/ml) did not inhibit total protein secretion into the medium. The percent inhibition of BGP production by IFN was independent of media serum concentration or cell density. IFN (100 U/ml) decreased the steady state level of BGP mRNA as measured by Northern analysis using an oligomeric probe for rat BGP. The decrease in hybridization signal for BGP mRNA was detectable by 1 h after IFN exposure and continued to decline at 6 and 24 h. Treatment with cycloheximide (5 micrograms/ml) blocked the inhibitory effect of IFN on steady state levels of BGP mRNA. These results suggest that IFN may inhibit bone formation by selective inhibition of osteoblast matrix protein production. The mechanism of IFN inhibition of BGP production is, at least in part, pretranslational.

Amino Acid Sequence↗
PubMed1990

The right to refuse treatment: an application of the economic principles of decision-making under uncertainty.

When courts do not defer to professional medical judgement alternative ways must be found to make treatment decisions for persons who are deemed incompetent. Rather than impose the preferences of society upon the mentally ill individual, US courts favoured alternative procedures such as substituted judgement and the principle of the patient's best interest.

Antipsychotic Agents↗
PubMed1990

An analysis of peritonitis rates with bagless continuous ambulatory peritoneal dialysis (CAPD).

This study was performed to evaluate if the increased number of connections needed to perform bagless continuous ambulatory peritoneal dialysis (CAPD) with the Delmed system was associated with an increased incidence of peritonitis. All patients, from April 1986 through October 1988, using the Delmed bagless connection system, the Delmed bag system, and the Abbott spike system were included. Fifty patients (42.7 years at risk) received bagless CAPD (53 episodes of peritonitis; 1.24 episodes/patient year of dialysis); 56 patients (46.8 years at risk) utilized the Delmed bag technique (76 episodes of peritonitis; 1.63 episodes/patient year); and 45 patients (66.7 years at risk) utilized the Abbott system (155 episodes of peritonitis; 2.36 episodes/patient year of dialysis). The time to the first peritonitis episode was not significantly different between groups. Fifteen patients were switched from the Abbott system (2.3 episodes/patient years) to the Delmed bagless system (0.9 episodes/patient year, peritonitis; p less than 0.05) and 9 patients were switched from the Abbott spike system (2.3 episodes/patient years) to the Delmed bag system (1.4 episodes/patient years; p less than 0.01). It is concluded that the Delmed bagless system is not associated with an increased incidence of peritonitis and that the Delmed system is at least as good as the spike connection devices.

Adult↗
PubMed1990

Vancomycin absorption from the peritoneal cavity during dialysis-related peritonitis.

The uptake of vancomycin from the peritoneal cavity during acute episodes of peritonitis was compared to noninfected patients in 14 patients, 7 of whom had dialysis-related peritonitis. Treatment consisted of 8 hourly dialysate exchanges, followed by 4-h dwells containing 37.5 mg/L of vancomycin. On day 4, serum vancomycin concentrations were 13.4 +/- 4.8 mg/L in the controls and 15.5 +/- 6.8 mg/L in the group with peritonitis. After 180 min in the peritoneal cavity, 61% +/- 13% of the infused vancomycin remained in controls and 30% +/- 15% in patients with peritonitis (p less than 0.05). Uptake of vancomycin from the peritoneal cavity is enhanced during episodes of peritonitis.

Absorption↗
PubMed1990

Tobramycin absorption from the peritoneal cavity.

Previous studies have found serum tobramycin concentrations greater than 8 mg/L among patients undergoing treatment for peritonitis using hourly dialysate exchanges containing 10 mg/L of tobramycin. In this study, tobramycin absorption from the peritoneal cavity was evaluated among patients treated with exchanges of 180 min. intraperitoneal duration. Six patients in each group were studied. Mass transfer coefficients [MTC (mL/min.)] were calculated for noninfected (C) and peritonitis (P) periods. The mean MTC for C was 6.5 +/- 2.1 (SD) mL/min., and for P, 18.5 +/- 8.2 (SD) mL/min. (p less than 0.01). Peritonitis increased the rate of uptake from the peritoneal cavity. In these acute studies, the total dose of tobramycin delivered was small, so that serum concentrations remained less than 0.2 mg/L among controls and 0.5 mg/L among patients with peritonitis. Prolonged exposure to tobramycin, in association with more rapid absorption from the peritoneal cavity, may lead to serum concentrations greater than 8 mg/L.

Adult↗
PubMed1990

Digital clubbing due to secondary hyperparathyroidism.

Five patients in our dialysis population had digital changes suggestive of clubbing in association with severe secondary hyperparathyroidism. All had parathyroidectomies between June 1986 and December 1987. They represented 0.6% of the patients in our dialysis population and 17.8% of our patients who required operative management of secondary hyperparathyroidism. The clubbing was occasionally painful, and the digits were tender in response to palpation. Parathyroidectomy yielded excessive amounts of hyperplastic parathyroid tissue in each case. Postoperatively, the symptoms were relieved, when present, and the digital changes were stabilized. We believe that these findings are associated with severe secondary hyperparathyroidism and should be looked for in dialysis patients with renal osteodystrophy.

Adult↗
PubMed1990

Comparison of rehabilitation in patients undergoing home dialysis. Continuous ambulatory or cyclic peritoneal dialysis vs home hemodialysis.

Rehabilitation was assessed in 70 patients undergoing continuous ambulatory (CAPD; n = 67) or cyclic (CCPD; n = 3) peritoneal dialysis and 76 patients undergoing home hemodialysis (HHD). In the CAPD/CCPD group, there were more blacks (83% vs 53%) and diabetics (24% vs 8%). If patients too infirm to work were excluded, no statistically significant differences were found between those working for gain and in school (19% for CAPD/CCPD vs 32% for HHD); homemakers (16% for CAPD/CCPD vs 28% for HHD); and those not working (66% for CAPD/CCPD vs 41% for HHD). Although the CAPD/CCPD group had less formal education (8.9 +/- 3.7 years vs 10.9 +/- 2.2 years for HHD), illiteracy rates were similar (CAPD/CCPD, 16%; HHD, 7%). If unemployable (elderly and debilitated) patients were excluded, full rehabilitation was excellent in both groups (57% for CAPD/CCPD vs 65% for HHD), despite the greater number of blacks and diabetics in the CAPD group.

Adolescent↗
PubMed1989

Patterns of occult bleeding in asymptomatic colorectal cancer.

The assumption that asymptomatic colorectal cancers bleed provides the rationale for widespread stool screening. The authors studied 12 patients with unoperated colorectal cancer but without colorectal symptoms and six healthy volunteers as laboratory controls. All stools were collected for 2 weeks and analyzed by the HemoQuant and Hemoccult tests. In controls, the mean HemoQuant value was 0.7 mg hemoglobin (Hb)/g stool (range, 0.1-1.8) and all stools were Hemoccult-negative. In cancer patients, the mean HemoQuant was 3.3 mg Hb/g (range, 0.3-13.2); stools were within the normal HemoQuant range (less than 2 mg Hb/g) in 38% and negative by Hemoccult in 70%. The mean cancer detection rate testing a single stool per patient was 57% for HemoQuant and 25% for Hemoccult (P less than 0.001). The detection rate rose testing multiple stools and was maximal with five stools at 83% for HemoQuant compared to 31% for Hemoccult (P less than 0.001). The authors conclude that fecal blood levels are commonly normal with asymptomatic colorectal cancer. Although higher with HemoQuant than Hemoccult, cancer detection rates by fecal blood testing appear to be lower than previously reported.

Adenocarcinoma↗
PubMed1989

Efficacy of oral ciprofloxacin plus rifampin for treatment of malignant external otitis.

Malignant external otitis is an invasive pseudomonal infection characteristically afflicting the elderly patient with diabetes mellitus. Therapy has traditionally consisted of the long-term administration of combination parenteral antibiotics, but morbidity and mortality remain substantial despite this therapy. We treated 11 consecutive patients with the oral combination of ciprofloxacin (750 mg twice daily) and rifampin (600 mg twice daily) for 6 to 12 weeks (mean, 8 weeks). Pseudomonas aeruginosa was isolated from ear canal or mastoid, and bone destruction was documented by computed tomography in all patients. Seven patients (64%) had ear irrigation before onset of the infection. Ten patients fulfilled the criteria of both clinical and bacteriologic cure. No serious adverse reaction to either antibiotic was observed. Otalgia and otorrhea responded at a mean of 6 and 4 days, respectively, following the initiation of therapy. The erythrocyte sedimentation rate fell from a mean pretherapy value of 81 mm/h (range, 41 to 138 mm/h) to 18 mm/h (range, 3 to 45 mm/h) after the completion of antibiotic therapy. Minimum inhibitory and bactericidal concentrations established that all organisms were sensitive to ciprofloxacin. Time-kill curve and checkerboard assays failed to demonstrate either synergy or antagonism between ciprofloxacin and rifampin. Serum inhibitory and bactericidal titers showed minimal increase in inhibition and killing of the bacteria with the addition of rifampin. Rifampin did not alter the pharmacokinetics of ciprofloxacin. The successful use of oral antibiotics for this difficult infection may be a major advance. Reduction in antibiotic costs and hospitalization and convenience of oral administration were of notable benefit.

Aged↗
PubMed1989

Peritonitis secondary to dialysis tubing contamination among patients undergoing continuous ambulatory peritoneal dialysis.

Patients were asked to report all dialysis system contaminations occurring from December 1985 through May 1988 to the home training facility. There were 74 instances of peritoneal dialysis system contamination, 20 of which resulted in peritonitis. Prophylactic antibiotics were used in 48 of 54 episodes not resulting in peritonitis. Three cultures yielded gram-positive organisms without clinical peritonitis becoming evident. Fourteen of the 20 episodes of peritonitis had received antibiotics prophylactically. System contaminations were classified into tears or holes of the catheter at the adapter on the Tenckhoff catheter or at the tubing connection to the dialysate bag and breaks of the connecting devices from either dialysis catheter to dialysis tubing or dialysis tubing to dialysate bag. System contaminations accounted for 20 of the 333 episodes of peritonitis that occurred during this time. Identifying system contamination is useful because prophylactic antibiotic therapy may prevent peritonitis.

Anti-Bacterial Agents↗
PubMed1989

Survival on dialysis therapy: one center's experience.

Patient survival while undergoing renal replacement therapy was evaluated from January 1, 1967, through June 15, 1986. There were 1,216 patients, of which 230 were treated by continuous ambulatory peritoneal dialysis (CAPD), 150 by home hemodialysis (HHD), and the remainder by dialysis in a free-standing dialysis facility (LCD). Covariate analysis found that patient survival on dialysis therapy was not influenced by race, sex, or marital status. Patients more than 60 years of age and patients with renal failure secondary to diabetes mellitus or hypertension had the worst survival on dialysis. Patients entering into CAPD were associated with diminished survival when compared to HHD but not to LCD. The ability of the initial dialysis technique to maintain a person on dialysis was not different when patients were matched for age, race, and etiology of renal failure. Only a randomized prospective trial will answer the question as to whether continuous ambulatory peritoneal dialysis can maintain a patient at home as long as home hemodialysis.

Adolescent↗
PubMed1989

An analysis of ultrafiltration during acute peritoneal dialysis in rats.

Transport into and from the peritoneal cavity is effected through separate membranes. Peritoneal function is the sum of the contributions of these membranes. The peritoneal dialysis membranes are defined as intestinal viscera and mesentery, parietal lining membrane, and liver and diaphragm. The present study was undertaken to determine which of these membranes participate in ultrafiltration during peritoneal dialysis. Studies were performed in rats using a hypertonic (1200 mOsm/L) dialysate solution containing 5.6% glucose, 2.8% amino acid, and electrolytes. Both intact and eviscerated rats were studied. The experiments were repeated in animals whose diaphragms were fibrotic and densely adherent to liver. Preparation of the diaphragm did not impact upon ultrafiltration. Ultrafiltration in controls (54 vs. 56 ml with and without a fibrotic diaphragm respectively) and in eviscerated groups (44 vs. 45 ml with and without a fibrotic diaphragm respectively) were not significantly different. However, controls had significantly more ultrafiltration than did eviscerated animals (p less than 0.01). The parietal viscera accounted for 56-59% of the ultrafiltration. This study demonstrates that both the intestinal viscera and parietal walls participate in ultrafiltration.

Animals↗
PubMed1989

Focal glomerulosclerosis in Hodgkin's disease necessitating peritoneal dialysis.

A 16-year-old white boy had nephrotic syndrome due to focal segmental glomerulosclerosis six months before the diagnosis of Hodgkin's disease was established. Peritoneal dialysis was necessary for volume control after one month of unsuccessful therapy with high doses of corticosteroids. Nephrosis remitted after two courses of chemotherapy.

Adolescent↗
PubMed1989

Surgical adjuvant therapy of large-bowel carcinoma: an evaluation of levamisole and the combination of levamisole and fluorouracil. The North Central Cancer Treatment Group and the Mayo Clinic.

A total of 401 eligible patients with resected stages B and C colorectal carcinoma were randomly assigned to no-further therapy or to adjuvant treatment with either levamisole alone, 150 mg/d for 3 days every 2 weeks for 1 year, or levamisole plus fluorouracil (5-FU), 450 mg/m2/d intravenously (IV) for 5 days and beginning at 28 days, 450 mg/m2 weekly for 1 year. Levamisole plus 5-FU, and to a lesser extent levamisole alone, reduced cancer recurrence in comparison with no adjuvant therapy. These differences, after correction for imbalances in prognostic variables, were only suggestive for levamisole alone (P = .05) but quite significant for levamisole plus 5-FU (P = .003). Whereas both treatment regimens were associated with overall improvements in survival, these improvements reached borderline significance only for stage C patients treated with levamisole plus 5-FU (P = .03). Therapy was clinically tolerable with either regimen and severe toxicity was uncommon. These promising results have led to a large national intergroup confirmatory trial currently in progress.

Adult↗
PubMed1989

Therapy of metastatic carcinoid tumor and the malignant carcinoid syndrome with recombinant leukocyte A interferon.

Twenty-seven patients with metastatic carcinoid tumor, 24 of whom had the malignant carcinoid syndrome, were treated with recombinant leukocyte A interferon at a planned dose of 24 x 10(6) U/m2. Twenty percent of patients with measurable tumor experienced an objective regression and 39% of those with the carcinoid syndrome experienced a reduction of more than 50% in urine 5-hydroxyindoleacetic acid (5HIAA) excretion. Flushing was partially or completely relieved in 65% of patients and diarrhea was relieved in 33%. Regrettably, these favorable treatment effects were transient in nature, with objective regressions persisting for a median of only 7 weeks and hormonal responses for a median of only 4 weeks. Any therapeutic gain experienced by these patients seemed to be outweighed by the frequency and severity of toxic reactions, which consisted primarily of chills and fever, fatigue, anorexia, weight loss, leukopenia, and abnormalities of liver function. Whereas other interferons, administration by alternative dosages and regimens, or incorporation of interferons into drug combinations may merit future study, we cannot recommend recombinant leukocyte A interferon, administered by the methods we employed, for routine therapy of the carcinoid tumor or syndrome.

Adolescent↗