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Biomedical subjects

R Swartz

Publications and source records attributed to R Swartz.

At least 37 records · Page 2Linked to original sources
PubMed1994

Hepatic disease and psychiatric illness: relationships and treatment.

A relationship between hepatic diseases and psychiatric symptoms has long been speculated. While liver detoxication makes the exogenous substances harmless for the body, there are occasions where the liver may convert a harmless substance into a more toxic substance. With such an important role, the liver protects all the organs of the body. When liver is malfunctioning, toxic metabolites injurious to the brain may be produced. As the brain receives a high blood supply, a large amount of metabolites reach this organ. Hence, the metabolic function of the liver keeps a delicate reciprocal relationship between the two organs. In addition, a number of psychiatric medications affect liver functions. Another perplexing clinical problem is the difficulty in treating psychiatric symptoms in patients with liver disease. For example, benzodiazepines which do not affect the liver function in physically healthy psychiatric patients, may induce hepatic coma in patients with liver disease. Benzodiazepine antagonists produce dramatic and temporary improvement in patients with hepatic coma. Clinically, many psychoactive drugs produce hepatic complications. The very same drugs which produce hepatic side effects are required for the treatment of psychiatric symptoms in patients with hepatic disorders. To appropriately handle these situations, a thorough knowledge of the side effects of these drugs is necessary.

Hepatic Encephalopathy↗
PubMed1993

Comparative pharmacological, toxicological and antitumoral evaluation of free and liposome-encapsulated cisplatin in rodents.

The systemic toxicity and efficacy of cisplatin (CDDP) were examined in vitro and in vivo. Procedures were performed before and after the antineoplastic agent was encapsulated into multilamellar liposomes (L-CDDP). In vitro cytotoxicity evaluation in L1210 murine leukaemia and NIH OVCAR human ovarian cancer cells showed IC50 values of 0.14 and 0.05 micrograms/ml with CDDP or L-CDDP, respectively. In vivo, mice injected intravenously with L-CDDP had plasma levels of platinum 4-fold higher than with CDDP. The t1/2 alpha was 2 h and the t1/2 beta exceeded 48 h with L-CDDP; whereas a t1/2 alpha of 15 min and t1/2 beta of 12 h was observed with CDDP. The values of platinum in liver, spleen, kidneys, lungs and heart were substantially higher in L-CDDP-treated compared to CDDP-treated mice. Cytotoxic evaluation of both agents was tested in vitro (murine L1210 leukaemia and NIH OVCAR cell line) and in vivo (male CD2F1 mice). CDDP and L-CDDP showed similar cytotoxicity in tissue culture. At the highest dose given, 12 mg/kg intraperitoneally (i.p.), L-CDDP showed higher antitumour efficacy demonstrated by an increased life span of the mice. The CDDP treatment at the highest dose was lethal to all the tumour bearing mice. The nephrotoxicity in rats (blood urea nitrogen and creatinine evaluation) of L-CDDP administered i.p. was significantly less than with CDDP. In addition, the ability of kidney slices to transport organic anions [para-aminohippurate (PAH)] and consume O2 was substantially decreased in rats treated with free CDDP compared to L-CDDP. Accordingly, the liposomal encapsulation of CDDP attenuates its nephrotoxicity, but allows maintenance of antitumour efficacy and may be a potentially effective modality in clinical settings.

Animals↗
PubMed1992

Peritoneal dialysis in end-stage renal disease patients with preexisting chronic liver disease and ascites.

PURPOSE: Hemodialysis in patients with chronic liver disease and ascites may be complicated by intradialytic hypotension, limiting the amount of ultrafiltration and resulting in massive ascites. Successful maintenance peritoneal dialysis (PD) has not been previously reported as an alternative to hemodialysis in this population. PATIENTS AND METHODS: Nine patients with chronic renal failure, chronic liver disease, and tense ascites prior to beginning PD are described. All chronic PD catheters were placed percutaneously by the nephrology staff. Seven patients were maintained primarily on continuous ambulatory peritoneal dialysis, whereas two were on intermittent peritoneal dialysis. RESULTS: PD catheters were placed without serious hemorrhage or bowel injury. PD provided adequate clearance and volume maintenance for each patient. Fifteen episodes of peritonitis occurred in 18 patient-years of PD. All episodes of peritonitis were successfully treated with intraperitoneal antibiotics without catheter removal. Only one patient had a decline in the serum albumin level of 0.5 g/dL or more during the course of chronic PD. Three of the nine patients are still alive and on PD for durations of 18 to 24 months. One patient insidiously developed sclerosing peritonitis after 8 years on PD and is now on hemodialysis, and another patient switched to hemodialysis because she was no longer able to care for herself or to manage her PD. Four patients died while maintained on PD; three deaths were due to complications of liver failure within the first 4 months of PD and the fourth was due to empyema after 4 years of PD. CONCLUSION: PD can be used successfully to treat chronic renal failure in patients with chronic liver disease and ascites when the liver disease itself is not rapidly fatal. PD may be better tolerated than hemodialysis and perhaps should be the renal replacement treatment of choice in these patients.

Ascites↗
PubMed1992

Amino acid solutions for CAPD: rationale and clinical experience.

Protein-calorie malnutrition is present in a sizable proportion of dialysis patients. In CAPD patients, constant glucose absorption from dialysate may displace other calorie sources, such as protein, and may suppress the appetite, thus contributing to malnutrition. Use of amino acids in place of glucose as the osmotic agent has been studied extensively. Ultrafiltration and small-molecule clearance similar to that with glucose can be achieved with amino acid solutions, but nitrogenous waste produced by amino acids limits the extent to which they can replace hypertonic glucose. Side effects of CAPD with amino acids appear to be minor and easily manageable. Most studies have found at least some nutritional benefit of amino acid solutions in addition to that of lowering the glucose load. Short-term studies of amino acid solutions for dialysis indicate that they may improve protein nutrition in malnourished CAPD patients.

Amino Acids↗
PubMed1991

Production of cell mass and pertussis toxin by Bordetella pertussis.

The cultivation of Bordetella pertussis affects production of pertussis toxin and biomass. Comparison of batch mode, chemostat operation and pHstat-turbidostatic control showed that productivities for the continuous process were greater than that for the batch operation. Continuous operation in balanced growth at the maximum specific growth rate, provided by the pHstat, resulted in the maximum specific production rate. Because of the strong association of pertussis toxin synthesis and cell growth, the concentration of toxin in the effluent of the continuous processes was greater than the maximum obtained in the batch bioprocess. An expanded Luedeking-Piret model of product formation kinetics fits the observed chemostat data and demonstrates that the production of pertussis toxin from the culture of B. pertussis is predominantly growth associated.

Bordetella pertussis↗
PubMed1991

Simultaneous catheter replacement and removal in refractory peritoneal dialysis infections.

The present report describes more than nine years of experience with simultaneous removal and replacement of the chronic peritoneal dialysis (PD) catheter in treating refractory mechanical and infectious complications. Simultaneous catheter replacement and removal not only succeeded in 22 of 23 cases with non-infectious mechanical complications, allowing uninterrupted PD in all but three, but also succeeded in 30 (83%) of 36 additional cases with persisting or recurring infection. Simultaneous procedures failed in six (17%) of 36 infectious cases, due to persistent infection in two cases and to procedure complications in four cases. The clinical characteristics of the 30 successful infectious cases were compared to the characteristics of both the six failures, as well as 29 additional infectious cases in which the peritoneal catheter was removed but was not replaced because of a variety of serious complications (such as pancreatitis, abscess, sepsis, or fluid overload). At the time of simultaneous catheter replacement in successful cases, temporary control of active peritoneal inflammation was achieved more frequently (80% vs. 31%, P less than 0.001) with a shorter interval of antibiotic coverage (6.4 +/- 0.9 vs. 14.7 +/- 1.3 days, P less than 0.001). In addition, the successful cases were characterized by significantly more Staphylococcal infections (70% vs. 26%, P less than 0.001) and significantly fewer Pseudomonal or fungal infections (6% vs. 59%, P less than 0.001), although successful cases included some non-Pseudomonal, non-enteric gram negative infections (23%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Preventing Staphylococcus aureus infection during chronic peritoneal dialysis.

In the interest of studying the prevention of chronic peritoneal dialysis infections, serial studies of the bacterial epidemiology in peritonitis and of antibiotic prophylaxis, respectively, were carried out. For 18 months, prospective evaluation of catheter exist site cultures, performed at the time patients developed acute peritonitis, showed that Staphylococcus aureus peritonitis was associated with concordant S. aureus at the exist site in 85% of cases, significantly more frequent than that for other organisms (P less than 0.02). Furthermore, active inflammation along with concordant culture results at the exit site characterized more than 60% of S. aureus peritonitis cases, also significantly more than that for other organisms (P less than 0.01). Over the ensuing 2 yr, patients beginning chronic peritoneal dialysis with a new percutaneously placed catheter were prospectively entered into a randomized, controlled trial of long-term antibiotic prophylaxis with trimethoprim-sulfamethoxasole. Patients receiving prophylaxis tended to have fewer episodes of peritonitis; however, the lower rate of peritonitis reached statistical significance only comparing patients who were S. aureus carriers at entry into the study to patients who were not S. aureus carriers. In particular, the prophylaxis trial seemed to reduce the specific incidence of S. aureus peritonitis overall, with S. aureus appearing in only 2 of 28 total peritonitis episodes among treated patients as compared with 11 of 37 total episodes among non-treated patients (P less than 0.01). Further analysis of the time to first peritonitis suggests that the effect of prophylaxis was most prominent during the first 3 months of therapy (P less than 0.02) rather than later in the course of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1991

Dialysis-related amyloid arthropathy: MR findings in four patients.

Dialysis-related amyloidosis is a recently recognized complication of long-term hemodialysis. It is caused by the deposition of a unique form of amyloid derived from circulating beta 2-microglobulin. This study describes the MR imaging characteristics in five articular sites of four symptomatic patients with biopsy-proved (three patients) or clinically and radiographically suspected (one patient) dialysis-related amyloidosis. Three wrists, one knee, and one cervical spine were examined. The extent of osseous and soft-tissue involvement at each joint site was well shown by MR imaging. Lesions that were apparently intraosseous on conventional radiographs were shown to be caused by well-defined erosions that extended to the articular surface. The MR signal characteristics of the amyloid deposition were intermediate between those of fibrocartilage and muscle on all sequences, distinguishing the deposition from cellular lesions or those containing large amounts of water, such as inflammatory masses, acute or chronic synovitis, and brown tumors of hyperparathyroidism. The intraarticular masses were associated with a moderate joint effusion in the large joint imaged, and small effusions were present in the wrist. Use of a fat-suppression sequence enhanced visualization of amyloid deposits within the wrist of one patient but provided no additional information in the knee of a second patient. Our experience suggests that MR imaging is well suited to showing the extent and distribution of articular disease in dialysis-related amyloidosis.

Amyloidosis↗
PubMed1990

The curled catheter: dependable device for percutaneous peritoneal access.

The curled peritoneal dialysis catheter is theoretically less prone to catheter migration and drainage failure. It also allows percutaneous placement, rather than surgical placement exclusively, whenever desired or necessary. Review of 213 curled-catheter placements, 134 (63%) percutaneous and 79 (37%) surgical, over the last 4 years, shows that the probability of continuing catheter function by life-table analysis was 88% at one year, 71% at 2 years, and 61% at three years, with no difference comparing percutaneous to surgical placement. Among the 213 total cases, nearly 50% of all catheters were still functioning at last follow up, and 38 catheters (17.8%) have been lost in total, attributed to infectious complications in 24 cases (tunnel-exit infection alone in 5, peritonitis alone in 11, combined infection in 8), refractory drain failure in 9 cases (early drain failure in 4, late drain failure in 5), recurrent late subcutaneous dialysate leaking in 3 cases, and peri-catheter hernia in 2 cases. Among other complications, the incidence of early drain failure (7.0%), and late drain failure (4.2%), compare favorably to reports describing other devices or other placement methods having comparable size of reported experience. Analyzing our own percutaneous and surgical placements separately, there were no differences in the respective frequencies of early drain failure, late drain failure, late subcutaneous dialysate leaking, outer cuff extrusion, required hernia repair, peritonitis or tunnel-exit infection. Only early external dialysate leaking was more frequent using percutaneous placement methods (21.6% vs. 10.1%; p less than 0.05), although no catheters were lost due to early external leaking.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1990

Hemodialysis-associated febrile episodes: surveillance before and after major alteration in the water treatment system.

Surveillance for bacteremic or pyrogenic episodes associated with hemodialysis was undertaken before and after the reconstruction of the water treatment system at our University medical center. The new water system included a holding tank with iodination treatment. The water delivered to individual dialysis stations had only occasional positive bacterial cultures (3 of 21 samples before completion of construction, 2 of 16 samples afterwards) and intermittent detection of endotoxin (6 of 21 samples before completion of construction, 9 of 16 samples afterwards) at monthly sampling. Among 51 individual dialysis treatments (25 patients) before reconstruction and 56 treatments (29 patients), after, only 2 and 3 febrile events were identified, respectively. All of these were associated with underlying infectious illness and not with the hemodialysis procedure itself. Overall, we conclude that pyrogenic episodes associated directly with hemodialysis treatment are infrequent, and that the addition of a water storage tank with iodination treatment does not appear to increase the risk of bacteremia or pyrogenic episodes.

Academic Medical Centers↗
PubMed1989

Antiandrogenic treatment of benign prostatic hyperplasia: a placebo controlled trial.

In a randomized triple-blind multicentre study, injections with the anti-androgenic agent oxendolone were compared with placebo in the treatment of benign prostatic hyperplasia. Thirty patients were treated with weekly injections of oxendolone 200 mg during a 3 months' period, and 30 patients were allocated to placebo treatment. During oxendolone treatment the maximum urinary flow rate increased statistically significantly (from 6.8 ml/s to 8.2 ml/s). However compared to placebo, the oxendolone effect was statistically insignificant. A slight but statistically significant improvement of the symptoms "sensation of retention", "urgency" and "frequency", was observed following oxendolone treatment, but an almost identical effect was seen in the placebo group. Following either treatment no change was observed in the residual urine volumes, in prostatic volume as measured by transrectal ultrasonotomography, or in any other therapeutic parameters. Conservative treatment of benign prostatic hyperplasia with the antiandrogen oxendolone in a dose of 200 mg a week cannot be recommended for clinical use.

Aged↗
PubMed1989

Acinetobacter peritonitis during chronic peritoneal dialysis.

Among gram-negative bacilli isolated during peritonitis in chronic peritoneal dialysis (CPD), Pseudomonas species are most common but Acinetobacter species are nearly as frequent. A survey of more than 450 patient-years' experience with CPD revealed 23 episodes of Acinetobacter peritonitis (AP), making this the second most common form of gram-negative peritonitis. Concomitant break in sterile technique and exit-site/tunnel infection were infrequent. AP appeared as the first peritonitis episode in five cases and as the second in six cases, and the duration of CPD at the time of AP ranged from less than 1 to greater than 56 months. However, AP was noted to appear shortly after treatment of another peritonitis episode or shortly after CPD access placement, within 2 months in 11 cases (47%) and within 3 months in 14 cases (61%). Treatment with intraperitoneal antibiotics succeeded in 21 cases (91%) without CPD interruption or catheter removal, with tobramycin or gentamicin alone in 16 cases, and with combined aminoglycoside and penicillin or cephalosporin in six cases. In two cases intraperitoneal antibiotics alone were insufficient therapy: one case with concomitant tunnel infection and dialysate leak and one case with bacteremia while receiving corticosteroids. The time-dependent incidence of AP suggests opportunistic infection during a vulnerable period in the first 2 to 3 months following another peritonitis episode, but AP also appears amenable to intraperitoneal antibiotic therapy alone without interruption of the CPD routine in the majority of cases.

Acinetobacter Infections↗
PubMed1989

Disconnect during continuous ambulatory peritoneal dialysis (CAPD): retrospective experience with three different systems.

Disadvantages of continuous ambulatory peritoneal dialysis (CAPD), such as inconvenience and bulkiness of the apparatus, inflexibility of infusion volume, and predictable peritonitis incidence may be altered by using systems which allow disconnection from the tubing and bag after each exchange. At University of Michigan we have followed 35 patients using the O set with sodium hypochlorite (Baxter Healthcare Corp.) for 15.5 +/- 10 months, 16 patients using the Y configuration Ultraset (Baxter Healthcare Corp.) for 8.1 +/- 5 months, and 6 patients using a universal adapter (Delmed Corp.) for 14.3 +/- 7 months. Failure occurred in 7 cases (18%) at 12 +/- 8 months using the O set (3 elective, 3 related to peritonitis, 1 ultrafiltration difficulty), and 1 (7%) at 3 months using the Ultraset (related to peritonitis). Accidental sodium hypochlorite infusion occurred 8 times in 6 patients, 4 patients still on CAPD without residual effect and 2 in whom infusion contributed to failure but not to ultrafiltration difficulty. Cumulative per-patient-year (episode/months) peritonitis rates of 0.75 (1/16.4), 0.65 (1/18.4) and 0.88 (1/14.3), respectively, compare favorably with the overall center experience of 0.96 (1/12.2) (NIH-CAPD Registry). Peritonitis rates did not differ during use of any of the disconnect systems between patients with prior CAPD experience compared to patients without prior CAPD experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Musculoskeletal symptoms related to arthropathy in patients receiving dialysis.

We evaluated musculoskeletal complaints related to arthropathy in 28 patients with end stage renal failure receiving maintenance dialysis. Twenty-three of 28 patients had arthritic complaints and 14 had an arthropathy. Six of 14 patients with arthropathy had a pattern resembling calcium pyrophosphate dihydrate deposition (CPPD) disease, 4 patients had moderately severe osteoarthritis, 3 had calcific periarthritis, and 1 patient had acute arthritis with intermittent pain and swelling. Factors which predispose to metabolic arthropathies were observed as follows: 29% elevated ferritin; 39% history of hyperparathyroidism; 68% elevated parathormone; 54% hyperphosphatemia; 36% hypercalcemia, 29% HLA haplotypes A3, B7, or B14; and 60% hyperaluminemia. The arthropathy group had more abnormalities per patient (mean 3.6) than the group without arthropathy (mean 2.7) (p less than 0.05). Our data suggest that (1) arthritic complaints occur frequently in patients receiving dialysis; (2) arthropathy accounted for 61% of the complaints; (3) 43% of patients with arthropathy had CPPD-type; (4) renal osteodystrophy caused 17% of arthritic complaints; and (5) in patients receiving dialysis, there is a high incidence of metabolic abnormalities that are known to be associated with arthropathy.

Adult↗
PubMed1987

Male infertility. 1. Patient evaluation.

Although the cause of male infertility is often obscure, proper evaluation can reveal physiologic abnormalities on which a concept of management can be based. Evaluation includes history taking, physical examination, laboratory studies, semen analysis, radiographic studies, and occasionally, testicular biopsy and other studies. The history and physical examination are the foundation of evaluation and may provide clues to diagnosis. However, semen analysis is the most informative test in evaluation of male infertility. For optimum results, proper collection techniques must be followed and data must be carefully interpreted.

Humans↗