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Biomedical subjects

Z Korzets

Publications and source records attributed to Z Korzets.

At least 91 records · Page 5Linked to original sources

Increased drainage volume in intermittent peritoneal dialysis using a two-bag, low hydrostatic pressure drainage system.

Adequate drainage volume (DV) is a prerequisite for long-term success of intermittent peritoneal dialysis (IPD). Ultrafiltration (UF) is basically determined by the interplay of two major forces: a driving osmotic force created by a hyperosmolar dialysate solution versus an opposing force--the intraperitoneal hydrostatic pressure. Conventional drainage procedures (CS) are capable of achieving a fluid volume of 3 L per bag. We found that this intrabag volume corresponds to an intrabag hydrostatic pressure of 60 cm water. Because this drainage system is closed, the intrabag hydrostatic pressure reflects intraperitoneal hydrostatic pressure. A low-pressure system (LPS) was devised to evaluate the possible influence on DV of reducing HP. Our results show that such LPS does indeed significantly improve DV, using a decreased number of exchanges. The residual volume and its glucose concentration (in a 1.5-g/dl exchange) were measured with CS. When followed by an 4.25-g/dl exchange, an 11% reduction in glucose concentration was evident. Thus, the osmotic driving force may also be impaired by incomplete drainage. To obtain maximal DV during IPD, a LPS should be used. This could be achieved by using 2 L dialysate in 3-L bags.

Aged↗

Total parathyroidectomy with autotransplantation in haemodialysed patients with secondary hyperparathyroidism--should it be abandoned?

The development of secondary hyperparathyroidism is almost universal in patients with end-stage renal disease. Medical management frequently fails and in such circumstances parathyroidectomy becomes a necessity. Total parathyroidectomy with autotransplantation of parathyroid tissue into the patient's forearm has been advocated as the surgical procedure of choice. In a previous publication we reported our experience with this technique in six haemodialysed patients. We now extend our follow-up to 19 patients over an observation period ranging from 6 to 66 months. Five of these patients required graft removal because of recurrent secondary hyperparathyroidism. Despite total graft removal, two patients had clinical and laboratory evidence of persistent hyperparathyroidism. Histology of the removed graft tissue demonstrated severe hyperplasia as well as invasion of adjacent muscle, adipose tissue, and vascular channels by parathyroid cells. This raises the possibility of local and distant metastatic spread of parathyroid tissue resulting in hyperparathyroidism. We suggest that parathyroid autotransplantation is potentially hazardous and should in fact be abandoned.

Female↗

Acute renal failure due to sarcoid granulomatous infiltration of the renal parenchyma.

A 56-year-old female with evidence of multisystem involvement due to sarcoidosis presented with acute renal failure. Percutaneous renal biopsy revealed sarcoid granulomatous infiltration of the renal parenchyma. Steroid therapy resulted in a prompt improvement of renal function. A review of the literature has disclosed 16 similar cases. Pertinent clinical and laboratory data and treatment regimens are discussed.

Acute Kidney Injury↗

Reversible renal failure due to psychogenic urinary retention.

A case of advanced, reversible renal failure due to psychogenic urinary retention occurring in a 17 year old female, is reported. The diagnosis of psychogenic urinary retention was made on the basis of existent florid psychopathology and the concomitant exclusion of an organic cause. Family psychodynamics are discussed. Psychosocial intervention led to a resumption of normal micturition, the disappearance of the urinary retention with resultant improvement of renal function.

Acute Kidney Injury↗

Urinary kallikrein in normal pregnancy, pregnancy with hypertension, and toxemia.

The 24-hour urinary excretion of kallikrein (K) and prostaglandin E2 (PGE2), which reflects their intrarenal synthesis, was measured in 7 normal women (NW), 10 women with essential hypertension (EH), 26 normal pregnant women (NP), 12 women with hypertension in pregnancy (HP), and 4 women with toxemia. All pregnant women were in the last trimester of their pregnancy (week 24-40). K was raised in NP (99.6 +/- 8.1 KU/24 h) and HP (106.5 +/- 8 KU/24 h) compared to NW (57 +/- 8.23 KU/24 h) (p less than 0.05). PGE2 excretion was decreased in EH (403.25 +/- 90.6 ng/24 h) compared to NW (508.6 +/- 80.26 ng/24 h). During pregnancy PGE2 was increased to 1,088 +/- 93.2 ng/24 h in NP and significantly more in HP, 1,885 +/- 40 ng/24 h (p less than 0.002). In this regard it differed from K. These data may suggest that, in addition to K, other factors (as angiotensin II and/or antidiuretic hormone) possibly activate renal PGE2 production in HP. In toxemia, K (23 +/- 6.1 KU/24 h) and PGE2 (583 +/- 172.83 ng/24 h) were markedly decreased. The above results suggest that the renal kallikrein-kinin and prostaglandin systems may play a role in sodium homeostasis during pregnancy. Their exact influence on the pathogenesis of hypertension in nonpregnant, pregnant, and toxemic subjects awaits further investigation.

Adolescent↗

The urinary excretion of prostaglandins E2 and F2 alpha in essential hypertension.

The 24 h urinary excretions of prostaglandins E2 (E2/d) and F2 alpha (F2 alpha/d) were measured in twenty-five normal subjects and in thirty-five patients with essential hypertension [seventeen with low renin (LRH) and eighteen with normal renin (NRH) hypertension]. E2/d was lower in patients with LRH than in normal subjects (P less than 0.01), whereas no difference was found between patients with NRH and the controls. F2 alpha/d was similar in patients with LRH and in the normal subjects, but was significantly greater in patients with NRH (P less than 0.02). The ratio of prostaglandin E2 to prostaglandin F2 alpha was decreased in hypertensive patients (P less than 0.02), although in the NRH subgroup the difference was not statistically significant. It appears that LRH is associated with impaired production of prostaglandin E2, while a deranged relationship between the two prostaglandins exists in all the patients with essential hypertension. These changes in prostaglandin production could possibly contribute to the pathogenesis of hypertension, by increasing renal vascular resistance and decreasing sodium excretion. Alternatively, they might be a secondary phenomenon, reflecting changes in renal prostaglandin metabolism induced by the hypertensive state.

Adult↗

Successful management of severe paraquat poisoning.

A case of paraquat poisoning was successfully treated which would have been considered lethal according to a reported prognostic index. Main features in the treatment were removal of paraquat by gastric lavage, forced diuresis, hemodialysis, and charcoal hemoperfusion. Early ventilation with low FIo2 and with positive end-expiratory pressure (PEEP) were also utilized.

Charcoal↗

Successful parathyroid gland autotransplantation after total parathyroidectomy in dialysis patients.

Secondary hyperparathyroidism is one of the major complications encountered in patients on maintenance dialysis. Medical management is frequently unsuccessful, and there is often a need to perform a parathyroidectomy. Recurrent clinical secondary hyperparathyroidism may occur as a sequela of subtotal parathyroidectomy and necessitate a reexploration of the neck. Total parathyroidectomy followed by autotransplantation of parathyroid tissue into the patient's forearm bypasses the need for a second operation, and it provides a simple ambulatory procedure, under local anesthesia, for the removal of hyperplastic parathyroid tissue. The results in six patients indicate that this new procedure should be considered the treatment of choice for this condition.

Adult↗

Effect of chronic and acute changes in sodium balance on the urinary excretion of prostaglandins E2 and F2 alpha in patients with essential hypertension.

The 24-hour urinary excretion of prostaglandins (PGs) E2 and F2 alpha, plasma renin activity (PRA), and aldosterone were measured in 7 normal subjects and 8 patients with essential hypertension before and after 5 days of a diet containing less than 20 mmol/day of sodium. Subsequently, sodium was infused intravenously for 4 h (77 mmol/h), and urinary PGs measured in hourly urine collections. Plasma renin activity and aldosterone were measured at hours 2 and 4. In the normal subjects, PGE2 increased significantly (p less than 0.0005), with the diet, while PGF2 alpha did not change. The E/F ratio was increased significantly (p less than 0.01). In contrast, in the hypertensive patients no changes were observed in PGs excretion or in the E/F ratio. PRA and aldosterone were in the normal range after the diet in 4 patients and low in the other 4. Apart from PRA and aldosterone levels, there were no differences between these two subgroups of patients, with regard to change in body weight, blood pressure or electrolyte excretion. PG excretions were also similar. With the Na infusion, PGs returned to control values in the normal subjects. In the hypertensive patients, PG excretion decreased to almost undetectable levels. This coincided with the phenomenon of exaggerated natriuresis. It is concluded that: (1) in hypertensive subjects PGs synthesis is not influenced by chronic changes in the volume status, and (2) renin secretion is relatively independent of PG production in the hypertensive subjects. We suggest that the changes in PG synthesis in hypertension are possibly related to altered sodium handling by the hypertensive kidney.

Adult↗

Is anemia of chronic renal failure related to secondary hyperparathyroidism?

A pathogenetic role of secondary hyperparathyroidism in the anemia of chronic renal failure has been suggested. To investigate this relationship, the biochemical factors of secondary hyperparathyroidism (calcium, phosphorus, alkaline phosphatase, and immunoreactive parathyroid hormone) were correlated with hematocrit levels in 96 long-term hemodialysis patients. We also compared hematocrit values before and after parathyroidectomy in 18 patients. No correlation between hematocrit level and biochemical indices of secondary hyperparathyroidism could be found. However, in 44% of the patients with parathyroidectomies, the hematocrit reading increased after surgery. The importance and possible cause of this improvement of anemia in this group is discussed.

Adolescent↗

Intraperitoneal infusion of glucose-based dialysate in the rat--an animal model for the study of peritoneal advanced glycation end-products formation and effect on peritoneal transport.

OBJECTIVE: Glucose-based dialysate induces non enzymatic glycation within the peritoneal cavity. To evaluate the relationship between the formation of advanced glycation end-products (AGEs) and peritoneal transfer for small solutes and macromolecules, we developed a model of simulated peritoneal dialysis (PD) in normal rats. METHODS: Male albino rats of the Charles River strain were divided into two sets of 3 groups (15-25 rats in each group). In the experimental (E) group, the rats were intraperitoneally (i.p.) injected daily with a commercially available 4.25% dextrose solution. In the control puncture (CP) group, the peritoneum was punctured daily, but no PD solution infused. In an age-matched control (CC) group, no intervention was given. Two study protocols were used. Protocol A (duration 20 weeks) consisted of a daily i.p. injection of 10 mL PD solution per 100 g body weight. In protocol B, a double volume of PD solution was introduced (20 mL per 100 g body weight). At 9, 16, and 20 weeks in protocol A, and at 9 weeks in protocol B, urea, creatinine, microalbumin [(MAL) measured using specific anti-rat albumin monoclonal antibody], and AGEs (measured by fluorescent assay with excitation at 370 nm and emission at 440 nm) were measured in peritoneal effluent and serum. RESULTS: At no time during the study were AGEs detected in serum from any group in either protocol. In both protocols, no differences were found between the control groups (CP, CC) with respect to all parameters. In protocol A, the dialysate-to-plasma ratio (D/P) of urea was significantly higher in the experimental group as compared with the control groups at 9, 16, and 20 weeks [9 weeks: 0.59 +/- 0.03 (E) vs 0.39 +/- 0.02 (CP) vs 0.46 +/- 0.02 (CC), p < 0.0004 and p < 0.002, respectively; 16 weeks: 0.71 +/- 0.08 (E) vs 0.42 +/- 0.01 (CP) vs 0.46 +/- 0.01 (CC), p < 0.0001 and p < 0.02, respectively; 20 weeks: 0.57 +/- 0.03 (E) vs 0.39 +/- 0.01 (CP) vs 0.41 +/- 0.02 (CC), p < 0.002 and p < 0.004, respectively]. At 16 and 20 weeks, dialysate MAL levels were significantly increased in group E [16 weeks: 354.00 +/- 80.35 microg/mL (E) vs 134.75 +/- 14.36 microg/mL (CP) vs 110.69 +/- 7.83 microg/mL (CC), p < 0.04 and p < 0.03, respectively; 20 weeks: 283.17 +/- 14.71 microg/mL (E) vs 105.14 +/- 12.11 microg/mL (CP) vs 135.50 +/- 19.03 microg/mL (CC), p < 0.00001 and p < 0.0001, respectively]. In protocol B, at completion of the study (week 9), D/P urea, effluent MAL, and AGEs were significantly higher in the experimental group as compared with the control groups [D/P: 0.67 +/- 0.04 (E) vs 0.46 +/- 0.07 (CP) vs 0.41 +/- 0.02 (CC), p < 0.0002 and p < 00001, respectively; MAL: 336.8 +/- 63.30 microg/mL (E) vs 125.71 +/- 16.77 microg/mL (CP) vs 119.00 +/- 39.75 microg/mL (CC), p < 0.008 and p < 0.007, respectively; AGEs: 265.77 +/- 33.49 U/mg creatinine (E) vs 163.10 +/- 21.99 U/mg creatinine (CP) vs 83.17 +/- 22.66 U/mg creatinine (CC), p < 0.02 and p < 0.001, respectively]. Peritoneal effluent AGEs were found to be significantly correlated with D/P urea and dialysate MAL (r = 0.42, p < 0.04, and r = 0.7, p = 0.00001, respectively). CONCLUSIONS: In situ generation of AGEs constitutes the chief origin of peritoneal AGEs. Advanced glycation end-products affect peritoneal permselectivity for both small and large solutes. The rat model of simulated peritoneal dialysis developed in this experiment provides a reliable method for studying peritoneal AGE formation and effect on peritoneal transfer of small solutes and macromolecules.

Animals↗