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Biomedical subjects

R Selgas

Publications and source records attributed to R Selgas.

At least 109 records · Page 6Linked to original sources

Peritoneal functional parameters after five years on continuous ambulatory peritoneal dialysis (CAPD): the effect of late peritonitis.

Functional stability of the peritoneum is essential for patients on long-term continuous ambulatory peritoneal dialysis (CAPD) treatment. Sixteen patients on CAPD treatment for at least 4 years were studied. Their mean age was 47 +/- 15 years, 5 were males, and none were diabetic. Residual creatinine clearance at the beginning was 2.1 +/- 2.6 mL/min. Once yearly since starting CAPD, we have evaluated their peritoneal ultrafiltration (UF) and diffusion capacities by calculating the peritoneal mass transfer coefficient (MTC, mL/min) for urea and creatinine. Patients were categorized so that we could distinguish the effect of peritonitis, betablockers, and hypertension. For all patients the average initial and final MTCs and UF values were not different. Early episodes of peritonitis (those occurring less than 36 months after starting CAPD) did not influence long-term function. However, late peritonitis (occurring greater than 36 months since initiation) induced a decrease in urea-MTC (22.3 +/- 6 to 15.8 +/- 3.9, p less than 0.05), creatinine-MTC (9.4 +/- 3.1 to 7.4 +/- 2.5, p less than 0.05), and a corresponding increase in UF (1.25 +/- 0.4 to 1.4 +/- 0.3, mL/min, p less than 0.05). Age, sex, betablockers and hypertension did not influence the peritoneal parameters followed. After 5 years on CAPD, functional stability of the peritoneum is evident, except for patients who suffer late episodes of peritonitis. We speculate that the peritoneum in patients who have been on long-term CAPD are more susceptible to injuries, such as peritonitis, and that this results in functional deterioration.

Adrenergic beta-Antagonists↗

Insulin influence (used as an additive to dialysate) on the mitogenic-induced effect of the peritoneal effluent in CAPD patients.

Peritoneal effluent in CAPD patients is the result of the interaction between dialysate and patient through the peritoneal membrane. Among the factors transferred from the patient to dialysate are solutes capable of stimulating fibroblasts: Interleukin-I, Interferon-gamma, and other proteins. Insulin is a well known mitogenic coadjuvant able to act sinergistically with other mitogens in the stimulation of fibroblast proliferation under experimental conditions. Our objective has been to study the effect of insulin added to dialysate in vivo on the in vitro mitogen-induced capacity of the nocturnal peritoneal effluent in 8 diabetics. Two different samples were studied: basal and with in vivo added insulin with the patients' usual doses. A Swiss 3T3 line of mice fibroblasts was used for studies, adding 50 microliters of peritoneal effluent. To confirm in vivo potential mitogenic activity, we also added PDBu (Phorbol dibuturate), a well known mitogenic agent, to both samples. Furthermore, another growth factor, EGF (Epidermal growth factor), was also added to 5 other samples. Insulin addition to the CAPD bag transforms a non-mitogenic peritoneal effluent into a mitogenic one (mean: 4.4 times over basal). At the doses used in vivo there is no linear correlation between insulin dose and DNA synthesis (r: -0.28, NS). Both PDBu and EGF in vitro addition induced a remarkable increment in the mitogenic capacity of the peritoneal effluent. We conclude that insulin added to CAPD bags behaves as a remarkable mitogenic coadjuvant for mice fibroblasts. Consequently, its long-term and universal clinical use should be reconsidered.

Animals↗

Comparative study of two different routes for insulin administration in CAPD diabetic patients. A multicenter study.

CAPD has been considered an appropriate method for treatment of diabetics in renal failure. Up to now the choice of route for insulin administration in these patients has not been definitely defined, although there is a general consensus for employing the intraperitoneal route for this purpose. However, contradictory data have appeared on this subject. Our aim has been to investigate whether the subcutaneous or intraperitoneal route makes any difference to metabolic control, and if so what is the price in terms of the incidence of peritonitis. Two groups of diabetic patients from three different hospitals with a similar peritonitis incidence and training protocols were studied. Of the 30 patients, 15 were treated with subcutaneous insulin (sc group) and in the other 15 the intraperitoneal route was employed (ip. group). The average follow-up period was 20.8 +/- 7.5 months for sc group and 18.7 +/- 8 months for ip. group. Insulin requirements were 30 +/- 11 u./day in the sc. and 110 +/- 60 u/day in the i.p. group (p less than 0.05) and remained constant during the study period. Metabolic controls (home glucose levels, HbA1C, hospital fasting glucose levels) were similar for both groups. However, the incidence of peritonitis was 4 times greater in the ip. group. In the ip. group 18 peritonitis episodes were registered in 280 patient-months vs 5 episodes in sc. group in 312 patient-months. We conclude that the intraperitoneal route for insulin administration in diabetic CAPD patients produces a higher risk of suffering peritonitis with no real metabolic improvement in the medium term.

Blood Glucose↗

Induced changes of the peritoneal diffusion capacity by smoking, intraabdominal hypertension and omentectomy.

UNLABELLED: Peritoneal membrane suffers in some CAPD patients changes which modify its functionalism. In order to know whether these changes could be expected or appropriate, it is necessary to explore the general and particular conditions which can alter peritoneal physiology. Three aspects, smoking, intraabdominal hyperpressure and and omentectomy are situations which have not been included in the studies of peritoneal physiology. PATIENTS: The control group was constituted by 23 patients. Diabetics were studied as a separate group, with their own 10 patient controls. Smokers (1-20 cigarettes per day): 15 were non-diabetic patients, 9 were females. Diabetic smokers: 7 patients. Intraabdominal hyperpressure was determined by two big polycycstic kidneys (PCKD) in 8 patients, none diabetic. Omentectomy was performed in 6 non-diabetic and 9 diabetic patients. In all cases the procedure was prescribed because of an early catheter entrapment. Smoker patients show significant higher MTCs values for urea and creatinine than controls, but the slightly lower ultrafiltration value did not reached significant difference. Polycystic kidney patients showed lower MTCs values in respect to controls. Ultrafiltration capacity was similar. Omentectomized patients did not show any differences in respect to controls. In the diabetic patients group, neither ultrafiltration nor MTCs values presented significant differences between the established subgroups. So, smoking did not seem to induce higher MTC values as in the non-diabetic group. In conclusion, and according to the present results, two more situations should be taken into account in the evaluation of the peritoneal membrane dialyzing capacities: smoking, which increases diffusion capacity except for diabetics and PCKD with tow big kidneys, which decreases this capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗

Mycobacterium chelonei peritonitis due to hematogenous dissemination in a continuous ambulatory peritoneal dialysis patient.

Renal failure patients have been found to have a special susceptibility to Mycobacterium infections. In patients undergoing peritoneal dialysis, Mycobacterium chelonei peritonitis, due to penetration through the peritoneal catheter lumen, has been described. In our report, we described a case of disseminated M chelonei infection that began in a Thomas hemodialysis prosthesis and finally resulted in peritonitis of hematogenous origin. The diagnostic and therapeutic peculiarities are discussed.

Adult↗

Idiopathic IgA nephropathy presenting as malignant hypertension.

Three cases are reported of idiopathic IgA nephropathy (Berger's disease) presenting as malignant hypertension, with no data suggesting the underlying glomerulopathy, which was uncovered only after renal biopsy was performed. Comments are made on the validity of the pathological diagnosis, the possible pathogenetic sequence of the association, and on the eventual risks and benefits derived from performing renal biopsy in such patients.

Adolescent↗

Peritoneal vascular reserve characterization through nitroprusside-induced modification of peritoneal mass transfer coefficients.

The transport of solutes across the peritoneum may be increased by the topical administration of nitroprusside; the effects of the drug seem to be due to an increase in the number of perfused capillaries and/or in their permeability. We have compared the peritoneal mass transfer coefficients (MTC) for urea, creatinine and parathormone (PTH) under basal conditions and after administration of nitroprusside (4.5 mg/l dialysate) in 15 patients under CAPD therapy. The mean increments of the MTC were 48.8% for urea, 77.5% for creatinine and 323% for PTH. The relative MTC increments for the three molecules (taken in pairs) were: MTCPTH/urea' 2.53 times (mean), MTCPTH/creatinine' 1.7 times, and MTCcreatinine/urea' 0.73-times, with very variable ranges. The overall mean increment (OMI) for all three ratios ranged from -1.25 and +6 times. In six patients, some of the relative increments (and in three of them the OMI) were negative but the epidemiological features of these patients revealed no clear data. The OMI shows a direct correlation with the body surface area and an inverse correlation with the the duration of CAPD and ESRD and with the number of peritonitis episodes, albeit without statistical significance. We conclude that the peritoneal vascular reserve has individual characteristics, and that perhaps the OMI or some other similar index might serve to quantify and characterise it, if our findings are confirmed.

Adult↗

Hemolytic uremic syndrome in a patient with gastric adenocarcinoma: partial recovery of renal function after gastrectomy.

We report on a patient with gastric adenocarcinoma and severe renal failure caused by hemolytic uremic syndrome with predominantly vascular involvement. Evolution was favorable with partial recovery of renal function after tumor excision and administration of fresh plasma. Although microangiopathic hemolytic anemia is frequently associated with solid tumors, the appearance of a typical hemolytic uremic syndrome with carcinoma is exceptional.

Adenocarcinoma↗