Dialysis complications in acute kidney injury patients treated with prolonged intermittent renal replacement therapy sessions lasting 10 versus 6 hours: results of a randomized clinical trial

Prolonged intermittent renal replacement therapy (PIRRT) has emerged as an alternative to continuous renal replacement therapy in the management of acute kidney injury (AKI) patients. This trial aimed to compare the dialysis complications occurring during different durations of PIRRT sessions in critically ill AKI patients. We included patients older than 18 years with AKI associated with sepsis admitted to the intensive care unit and using noradrenaline doses ranging from 0.3 to 0.7 mu g/kg/min. Patients were divided into two groups randomly: in G1, 6-h sessions were performed, and in G2, 10-h sessions were performed. Seventy-five patients were treated with 195 PIRRT sessions for 18 consecutive months. The prevalence of hypotension, filter clotting, hypokalemia, and hypophosphatemia was 82.6, 25.3, 20, and 10.6%, respectively. G1 was composed of 38 patients treated with 100 sessions, whereas G2 consisted of 37 patients treated with 95 sessions. G1 and G2 were similar in male predominance (65.7 vs. 75.6%, P=0.34), age (63.6 +/- 14 vs. 59.9 +/- 15.5 years, P=0.28) and Sequential Organ Failure Assessment score (SOFA; 13.1 +/- 2.4 vs. 14.2 +/- 3.0, P=0.2). There was no significant difference between the two groups in hypotension (81.5 vs. 83.7%, P=0.8), filter clotting (23.6 vs. 27%, P=0.73), hypokalemia (13.1 vs. 8.1%, P=0.71), and hypophosphatemia (18.4 vs. 21.6%, P=0.72). However, the group treated with sessions of 10h were refractory to clinical measures for hypotension, and dialysis sessions were interrupted more often (9.5 vs. 30.1%, P=0.03). Metabolic control and fluid balance were similar between G1 and G2 (blood urea nitrogen [BUN]: 81 +/- 30 vs. 73 +/- 33mg/dL, P=1.0; delivered Kt/V: 1.09 +/- 0.24 vs. 1.26 +/- 0.26, P=0.09; actual ultrafiltration: 1731 +/- 818 vs. 2332 +/- 947mL, P=0.13) and fluid balance (-731 +/- 125 vs. -652 +/- 141mL, respectively) . In conclusion, intradialysis hypotension was common in AKI patients treated with PIRRT. There was no difference in the prevalence of dialysis complications in patients undergoing different durations of PIRRT.

Morphometric evaluation of the rat testis, epididymis and vas deferens following chemical sympathectomy with guanethidine

Selective chemical sympathectomy of the internal sex organs of adult male rats was undertaken by long term administration of low doses of guanethidine. The spermatogenic activity of the testis was unaffected by treatment. Examination of the vas deferens using morphometric methods revealed a marked increase in luminal area in contrast to a decrease in muscle layer area and in epithelial height. This is morphological evidence of sperm accumulation caused by a disorder in ductal contractile activity. No structural changes were observed in the epididymis. However, the concentration of spermatozoa in the sperm suspension stored in the cauda epididymidis was significantly increased in denervated rats. This result is discussed in terms of a sympathetic control of resorption mechanisms in the epididymis.

Evaluation of the presence of microorganisms in solid-organ preservation solution

OBJECTIVE: To assess the presence of microorganism contamination in the preservation solution for transplant organs (kidney/pancreas). Method: Between August 2007 and March 2008, 136 samples of preservation solution were studied prior to graft implantation. Variables related to the donor and to the presence of microorganisms in the preservation solution of organs were evaluated, after which the contamination was evaluated in relation to the recipient culture variable. Univariate and multivariate statistical analyses were performed. RESULTS: The contamination rate of the preservation solution was 27.9%. Coagulase-negative Staphylococcus was the most frequently isolated microorganism. However, highly virulent agents, such as fungi and enterobacteria, were also isolated. In univariate analysis, the variable donor antibiotic use was significantly associated to the contamination of the preservation solution. on the other hand, multivariate analysis found statistical significance in donor antibiotic use and donor's infectious complications variables. CONCLUSIONS: In this study, 27.9% of the preservation solutions of transplant organs were contaminated. Infectious diseases and non-use of antibiotics by the donor were significantly related to the presence of microorganisms in organ preservation solutions. Contamination in organ preservation solutions was not associated with infection in the recipient.

Interaction between the septal area and the subfornical organ in the control of water intake induced by thirst-eliciting procedures

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake. © 1980.

Natural killer activity in a medium-term multi-organ bioassay for carcinogenesis

Natural killer (NK) cell activity was evaluated after the initiation and promotion steps in a medium-term multi-organ bioassay for carcinogenesis. NK cell activity was assessed in vitro by Cr51 release assay at the 4th and 30th weeks of the experiment. Male Wistar rats were sequentially initiated with N-diethylnitrosamine (DEN i.p.), N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN drinking water), N-methyl-N-nitrosourea (MNU i.p.), dihydroxy-di-N-propylnitrosamine (DHPN drinking water) and N,N'-dimethylhydrazine (DMH s.c.) at subcarcinogenic doses for 4 weeks (DMBDD initiation). One group was evaluated at the 4th week and the other was maintained without any further treatment until the 30th week. Two initiated groups were exposed through the diet to 2-acetylaminofluorene (2-AAF) or phenobarbital (PB), from the 6th until the 30th week. Five additional groups were studied to evaluate the effects of each initiator on NK activity. All groups submitted to initiation only, initiation plus promotion, or promotion only, developed significantly more preneoplastic lesions than the untreated control group. The main target organs for tumor development in the initiated animals were the liver and the colon, irrespective of treatment with 2-AAF or PB. NK cell activity was not affected by exposure to genotoxic carcinogens after initiation, at the 4th week. Treatments only with PB or 2-AAF did not change NK cell activity. However, decreased NK cell activity was registered in the group only initiated with DMBDD and in the group given DMBDD+2-AAF. This late depression of NK cell activity at the 30th week could be related to the production of suppressing molecules by the tumor cells.

Morphological changes in the bone marrow of the dogs with visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Delayed tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline

Systemic antibiotic therapy (SAT) has usually been recommended after tooth replantation, but its actual value has been questioned. As there are no reports in the literature about its influence on tooth replantation, the aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in delayed rat tooth replantation. Ninety Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and bench-dried for 60 min. The dental papilla, enamel organ, pulp tissue, and root surface-adhered periodontal ligament were removed, and the teeth were replanted. The animals received no antibiotics (n = 30) or were medicated systemically with amoxicillin (n = 30) and tetracycline (n = 30), and were euthanized after 7, 15, and 30 days. Regardless of the evaluation period, the acute inflammatory infiltrate was less intense and root resorption presented smaller extent and depth in the group treated with amoxicillin. The results suggest that SAT has a positive influence on the repair process in delayed tooth replantation and that amoxicillin is an excellent treatment option.

Role of the medial septal area on the cardiovascular, fluid and electrolytic responses to angiotensin II and cholinergic activation into the subfornical organ in rats

In the present study we investigated the effect of electrolytic lesion of the medial septal area (MSA) on the pressor and dipsogenic response to cholinergic activation and angiotensin II (ANGII) injection into the subfornical organ (SFO) in rats. In addition the effect of MSA lesion on the natriuresis, kaliuresis and diuresis after cholinergic activation of the SFO was also investigated. Sham- and MSA-lesioned rats with a stainless steel cannula implanted into the SFO was used. The injection of ANGII (12 ng) into the SFO in sham rats produced pressor (24 ± 2 mmHg) and dipsogenic (9.6 ± 1.1 ml/h) responses. MSA lesion, both acute (2-6 days) and chronic (15-19 days), reduced the pressor (14 ± 2 mmHg) and dipsogenic (2.7 ± 1 ml/h) responses to ANGII into SFO. The injection of the cholinergic agonist carbachol (2 nmol) into the SFO in sham rats produced pressor (48 ± 4 mmHg), dipsogenic (10 ± 1.2 ml/h), natriuretic (457 ± 58 μEq/2 h) and kaliuretic (249 ± 16 μEq/2 h) responses. Acute, but not chronic MSA lesion reduced the pressor (27 ± 3 mmHg), natriuretic (198 ± 55 μEq/2 h) and kaliuretic (128 ± 16 μEq/2 h) responses to carbachol into SFO. No change in the dipsogenic response to carbachol into the SFO was observed in MSA-lesioned rats. Antidiuresis after carbachol was observed only in MSA-lesioned rats. The present results show that the MSA plays a role on the pressor, natriuretic and kaliuretic responses to cholinergic activation of the SFO in rats and on the pressor and dipsogenic responses to ANGII into the same area. In addition, they provide circumstancial evidence for separate circuits subserving the dipsogenic response to central cholinergic and angiotensinergic activation. A facilited diuresis after MSA lesion is also suggested.