126 resultados para Proximal Tubules
Resumo:
Avaliou-se, retrospectivamente, a evolução pós-operatória das varizes esofagogástricas em 40 pacientes submetidos a um dos seguintes procedimentos cirúrgicos: a (n=27) derivação esplenorrenal distal (ERD) e B (n=13) derivação esplenorrenal proximal (ERP). Todos os pacientes tinham hipertensão porta esquistossomótica com diagnóstico prévio de varizes do esôfago, presentes ou não no estômago, com um ou mais episódios de sangramento. Os pacientes foram submetidos a um dos procedimentos cirúrgicos de acordo com a preferência do cirurgião assistente. Foram realizadas, nesses pacientes, endoscopias no período pré-operatório e aos seis, 12 e 18 meses no pós-operatório. Os dados de cada endoscopia foram coletados e comparados entre os grupos, verificando-se a presença de varizes do esôfago e estômago nos diferentes períodos, comparando esses achados através do teste do qui-quadrado, com significância para p<0,05. Os resultados obtidos não mostraram casos de ressangramento até o 18º mês pós-operatório, nem casos de encefalopatia. Foram diagnosticadas varizes esofágicas, no pré-operatório, em 100% dos pacientes nos dois grupos. No período pós-operatório, houve redução significativa das varizes do esôfago, quando estudados os dois grupos conjuntamente, para 40% no sexto mês (p = 0,0002), 30% no 12º mês (p = 0,003) e 27,5% no 18º mês (p = 0,003). No sexto mês pós-operatório, a incidência de varizes do esôfago foi maior nos pacientes com ERD quando comparados àqueles com ERP (51,9% vs. 15,4%, p = 0,03). Quando estudadas as varizes aos 12 e 18 meses não foi observada diferença significativa entre pacientes submetidos a ERD ou ERP (12º mês, 37% vs. 15,4%; 18º mês, 25,9% vs. 30,8%). Foram vistas varizes gástricas em 37,5% dos pacientes, com redução significativa no sexto mês (2,5%, p = 0,005). Entretanto, quando comparada com a freqüência do sexto mês, houve aumento significativo no 12º mês (5%, p = 0,00001) e 18º mês (7,5%, p = 0,02). Quando comparados os grupos, no período pré-operatório, estas varizes estiveram presentes mais freqüentemente no grupo submetido a ERP (69,2% vs. 26%, p = 0,0005), sem diferença significativa no período pós-operatório (6º mês, 16,6% vs. 0%; 12º mês, 33,3% vs. 0%; 18º mês, 33,3% vs. 11,1%). Este trabalho demonstrou que os dois tipos de cirurgia têm resultado semelhante em relação à resolução das varizes do esôfago e estômago no 18º mês, mas os resultados indicam que a redução na incidência das varizes do esôfago se acompanha de aumento das varizes gástricas, provavelmente devido à abertura de novas vias colaterais de drenagem em casos de persistência de uma pressão porta aumentada ou mau funcionamento da derivação esplenorrenal.
Resumo:
OBJETIVO: Avaliar o efeito da colostomia proximal na cicatrização de anastomoses colocólicas em ratos com obstrução intestinal. MÉTODO: 72 ratos foram divididos em três grupos: grupo controle (C), submetido à anastomose colocólica e à colostomia proximal na ausência de oclusão intestinal; grupo sem colostomia (SC), submetido à oclusão intestinal de 72 horas e à anastomose colocólica primária; grupo com colostomia (CC) submetido à oclusão intestinal de 72 horas, à anastomose colocólica primária e à colostomia proximal. A cicatrização anastomótica foi avaliada em dois períodos, nos 2º e 7º dias de pós-operatório, em relação à deiscência anastomótica, aderências, epitelização mucosa, pressão de ruptura e a variáveis histológicas por estudo convencional e informatizado. RESULTADOS: verificou-se maior tendência a deiscência anastomótica no grupo SC (12,5%), e elevada incidência de complicações da colostomia no grupo CC (13%), entretanto tais resultados não apresentaram diferença estatística significante. No que se refere às demais variáveis analisadas para verificação da cicatrização anastomótica deve-se considerar que houve equivalência entre os três grupos nos dois períodos analisados. CONCLUSÃO: Não há diferença entre a cicatrização de anastomoses colocólicas associadas ou não à colostomia proximal, em ratos com obstrução intestinal.
Resumo:
OBJETIVO: Um dos maiores desafios no tratamento da hipertensão porta é o sangramento de varizes intestinais. O objetivo deste artigo é apresentar um novo tratamento para hemorragia entérica grave provocada por hipertensão porta cirrótica, utilizando a esplenectomia subtotal combinada com derivação esplenorrenal proximal. TÉCNICA: Uma paciente de 64 anos apresentou sangramento intenso proveniente de varizes em alça jejunal em Y de Roux, para derivação biliodigestiva, após lesão coledociana, complicada com cirrose hepática. O procedimento consistiu em esplenectomia subtotal, preservando o pólo superior do baço, suprido apenas pelos vasos esplenogástricos, e anastomose término-lateral da veia esplênica, em sua extremidade proximal, à veia renal esquerda. RESULTADOS: Esse procedimento foi seguro, sem sangramento maior, dificuldade técnica ou complicação. No acompanhamento de 30 meses, a paciente não teve novos episódios de sangramento, a cirrose não avançou e, atualmente, encontra-se bem, sob controle. CONCLUSÃO: A esplenectomia subtotal combinada com derivação esplenorrenal proximal é uma boa alternativa operatória para tratar hemorragia proveniente de varizes intestinais, decorrentes de hipertensão porta.
Resumo:
OBJETIVO: estudar, por meio da ultrassonografia perineal, as modificações da junção uretrovesical (JUV) e da uretra proximal (UP) promovidas pela cirurgia combinada de Marshall-Marchetti-Krantz-Burch (MMK-B). MÉTODOS: foi realizado um estudo de intervenção longitudinal e prospectivo. Trinta e duas mulheres com incontinência urinária de esforço foram submetidas à ultrassonografia perineal antes e 30 dias depois da cirurgia para avaliar a distância pubo-uretral (DPU), o comprimento da uretra proximal (UP), a distância horizontal da JUV (DHJUV) e a distância vertical da JUV (DVJUV), estando a paciente em repouso, e os seus deslocamentos durante a manobra de Valsalva. Os resultados foram expressos em médias e desvios padrão. Para a comparação dos resultados do pré aos do pós-operatório, foi usado o teste t de Student para amostra pareada quando as variáveis cumpriam os critérios do teste de normalidade, e o teste pareado de Wilcoxon quando não cumpriam. RESULTADOS: em comparação às medidas do pré-operatório, a cirurgia de Marshall-Marchetti-Krantz-Burch reduziu a DPU no repouso (13,4 mm x 10,2 mm) e no esforço (19,8 mm x 9 mm); reduziu a DHJUV no repouso (14 mm x 4,3 mm) e no esforço (20,8 mm x 6,4 mm); aumentou o comprimento da UP no repouso (16,7 mm x 19,7 mm) e no esforço (1,6 mm x 15,4 mm); aumentou a DVJUV no esforço (-5,4 mm x 14,8 mm). A cirurgia de MMK-B não alterou a DVJUV no repouso (16,2 mm x 18,7mm, p=0,085). CONCLUSÕES: a cirurgia de Marshall-Marchetti-Krantz-Burch reduziu significativamente a mobilidade vertical e horizontal da junção uretrovesical, porém sem elevar a junção uretrovesical.
Resumo:
A surgical technique for the treatment of ununited anconeal process in dogs treated by osteotomy and dynamic distraction of the proximal part of the ulna using a linear external skeletal fixator was evaluated. In all cases the osteotomy was distracted 1mm each day after the surgery until desired distraction had been achieved. Eight dogs and 9 joints diagnosed with ununited anconeal process were treated. The success of the procedure was determined by comparing clinical signs of lameness and degree of arthrosis at the time of diagnosis to 6 months after the surgical intervention. Radiographic union occurred in 88.9% of the affected joints between 21 and 42 days after the surgical procedure. Clinically, six elbows were classified as good, two as satisfactory and one as unsatisfactory. Six months after surgery two elbows had no arthrosis, one had Grade 1, two Grade 2 and one Grade 3. It is concluded the combination of ulnar osteotomy and dynamic distraction of the olecranon by a linear external skeletal fixator is a feasible procedure for the treatment of ununited anconeal process in dogs.
Resumo:
Abstract: The paired oviducal glands of immature and mature females of Mustelus schmitti were examined macro and microscopically. Findings indicate that these glands possessed the same zonation as in most chondrichthyans from anterior to posterior: club, papillary, baffle and terminal zones. The whole gland is composed by simple tubular glands that connect with transverse grooves all along the organ. The club zone presents a typical indian club shape with a simple columnar and ciliated epithelium including secretory cells PAS (+) and AB (+). The papillary zone is characterized by lamella forming small and long cones in numbers of three. The epithelium of this zone contains ciliated cells with apical nuclei and secretory cells with basal nuclei that stain AB (+)The baffle zone consists of apically flattened lamellae alternating with spinnerets which are small projections disposed by both sides of the plateau. This whole structure is present in number of 8 or 9 units. A simple columnar ciliated epithelium covers the plateau and spinnerets and no AB or PAS staining is observed. The epithelium of the terminal zone is PAS (-) and AB (+), and elongated tubules, that run adjacent to the baffle zone are the site where groups of spermatozoa are clearly observed in the lumen. The epithelium of the sperm storage tubules do not stain with any of the dyes tested. Sperm was also observed in the baffle zone, presumably in its way to the fecundation in the oviduct because it displays no aggregation pattern and was between the folds of the epithelium. By scanning electron microscopy sperm was observed in the club and baffle zones in a gland which belonged to a pregnant female.
Resumo:
(ANP, 1 µM) on the kinetics of bicarbonate reabsorption in the rat middle proximal tubule, we performed in vivo experiments using a stopped-flow microperfusion technique with the determination of lumen pH by Sb microelectrodes. These studies confirmed that ANG II added to the luminal or peritubular capillary perfusion fluid stimulates proximal bicarbonate reabsorption and showed that ANP alone does not affect this process, but impairs the stimulation caused by ANG II. We also studied the effects and the interaction of these hormones in cortical distal nephron acidification. Bicarbonate reabsorption was evaluated by the acidification kinetic technique in early (ED) and late (LD) distal tubules in rats during in vivo stopped-flow microperfusion experiments. The intratubular pH was measured with a double-barreled microelectrode with H+-sensitive resin. The results indicate that ANG II acted by stimulating Na+/H+ exchange in ED (81%) and LD (54%) segments via activation of AT1 receptors, as well as vacuolar H+-ATPase in LD segments (33%). ANP did not affect bicarbonate reabsorption in either segment and, as opposed to what was seen in the proximal tubule, did not impair the stimulation caused by ANG II. To investigate the mechanism of action of these hormones in more detail, we studied cell pH dependence on ANG II and ANP in MDCK cells using the fluorescent probe BCECF. We showed that the velocity of cell pH recovery was almost abolished in the absence of Na+, indicating that it is dependent on Na+/H+ exchange. ANP (1 µM) alone had no effect on this recovery but reversed both the acceleration of H+ extrusion at low ANG II levels (1 pM and 1 nM), and inhibition of H+ extrusion at higher ANG II levels (100 nM). To obtain more information on the mechanism of interaction of these hormones, we also studied their effects on the regulation of intracellular free calcium concentration, [Ca2+]i, monitored with the fluorescent probe Fura-2 in MDCK cells in suspension. The data indicate that the addition of increasing concentrations of ANG II (1 pM to 1 µM) to the cell suspension led to a progressive increase in [Ca2+]i to 2-3 times the basal level. In contrast, the addition of ANP (1 µM) to the cell suspension led to a very rapid 60% decrease in [Ca2+]i and reduced the increase elicited by ANG II, thus modulating the effect of ANG II on [Ca2+]i. These results may indicate a role of [Ca2+]i in the regulation of the H+ extrusion process mediated by Na+/H+ exchange and stimulated/impaired by ANG II. The data are compatible with stimulation of Na+/H+ exchange by increases of [Ca2+]i in the lower range, and inhibition at high [Ca2+]i levels
Resumo:
The present paper reviews work from our laboratories evaluating the importance of adrenal cortical hormones in acidification by proximal and cortical distal tubules. Proximal acidification was determined by stationary microperfusion, and measurement of bicarbonate reabsorption using luminal pH determination was performed with H+-ion-sensitive microelectrodes. Rats were adrenalectomized (ADX) 48 h before the experiments, and corticosteroids (aldosterone (A), corticosterone (B), and 18-OH corticosterone (18-OH-B)) were injected intramuscularly 100 and 40 min before the experiments. In ADX rats stationary pH increased significantly to 7.03 as compared to sham-operated rats (6.78). Bicarbonate reabsorption decreased from 2.65 ± 0.18 in sham-operated rats to 0.50 ± 0.07 nmol cm-2 s-1 after ADX. The administration of the three hormones stimulated proximal tubule acidification, reaching, however, only 47.2% of the sham values in aldosterone-treated rats. Distal nephron acidification was studied by measuring urine minus blood pCO2 differences (U-B pCO2) in bicarbonate-loaded rats treated as above. This pCO2 difference is used as a measure of the distal nephron ability to secrete H+ ions into an alkaline urine. U-B pCO2 decreased significantly from 39.9 ± 1.26 to 11.9 ± 1.99 mmHg in ADX rats. When corticosteroids were given to ADX rats before the experiment, U-B pCO2 increased significantly, but reached control levels only when aldosterone (two 3-µg doses per rat) plus corticosterone (220 µg) were given together. In order to control for the effect of aldosterone on distal transepithelial potential difference one group of rats was treated with amiloride, which blocks distal sodium channels. Amiloride-treated rats still showed a significant reduction in U-B pCO2 after ADX. Only corticosterone and 18-OH-B but not aldosterone increased U-B pCO2 back to the levels of sham-operated rats. These results show that corticosteroids stimulate renal tubule acidification both in proximal and distal nephrons and provide some clues about the mechanism of action of these steroids
Resumo:
Fractures are the feared consequences of osteoporosis and fractures of the proximal femur (FPF) are those that involve the highest morbidity and mortality. Thus far, evaluation of bone mineral density (BMD) is the best way to determine the risk of fracture. Genetic inheritance, in turn, is one of the major determinants of BMD. A correlation between different genotypes of the vitamin D receptor (VDR) and BMD has been recently reported. On this basis, we decided to determine the importance of the determination of VDR genotype in the presence of an osteoporotic FPF in a Brazilian population. We studied three groups: group I consisted of 73 elderly subjects older than 65 years (78.5 ± 7.2 years) hospitalized for nonpathological FPF; group II consisted of 50 individuals older than 65 years (72.9 ± 5.2 years) without FPF and group III consisted of 98 young normal Brazilian individuals aged 32.6 ± 6.6 years (mean ± SD). Analysis of VDR gene polymorphism by restriction fragment length polymorphism (RFLP) was performed by PCR amplification followed by BsmI digestion of DNA isolated from peripheral leukocytes. The genotype distribution in group I was 20.5% BB, 42.5% Bb and 37% bb and did not differ significantly from the values obtained for group II (16% BB, 36% Bb and 48% bb) or for group III (10.2% BB, 47.6% Bb and 41.8% bb). No differences in genotype distribution were observed between sexes or between the young and elderly groups. We conclude that determination of VDR polymorphism is of no practical use for the prediction of FPF. Other nongenetic factors probably start to affect bone mass, the risk to fall and consequently the occurrence of osteoporotic fractures with advancing age.
Resumo:
Systemic metabolic acidosis is known to cause a decrease in salt and water reabsorption by the kidney. We have used renal lithium clearance to investigate the effect of chronic, NH4Cl-induced metabolic acidosis on the renal handling of Na+ in male Wistar-Hannover rats (200-250 g). Chronic acidosis (pH 7.16 ± 0.13) caused a sustained increase in renal fractional Na+ excretion (267.9 ± 36.4%), accompanied by an increase in fractional proximal (113.3 ± 3.6%) and post-proximal (179.7 ± 20.2%) Na+ and urinary K+ (163.4 ± 5.6%) excretion when compared to control and pair-fed rats. These differences occurred in spite of an unchanged creatinine clearance and Na+ filtered load. A lower final body weight was observed in the acidotic (232 ± 4.6 g) and pair-fed (225 ± 3.6 g) rats compared to the controls (258 ± 3.7 g). In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 ± 0.05 g) compared to the other experimental groups (control, 1.46 ± 0.05 g; pair-fed, 1.4 ± 0.05 g). We suggest that altered renal Na+ and K+ handling in acidotic rats may result from a reciprocal relationship between the level of metabolism in renal tubules and ion transport.
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For several years it was believed that angiotensin II (Ang II) alone mediated the effects of the renin-angiotensin system. However, it has been observed that other peptides of this system, such as angiotensin-(1-7) (Ang-(1-7)), present biological activity. The effect of Ang II and Ang-(1-7) on renal sodium excretion has been associated, at least in part, with modulation of proximal tubule sodium reabsorption. In the present review, we discuss the evidence for the involvement of Na+-ATPase, called the second sodium pump, as a target for the actions of these compounds in the regulation of proximal tubule sodium reabsorption.
Resumo:
Patients with gastroesophageal reflux disease may have disturbances of gastric motility, which could play a role in the pathophysiology of the disease. Recent studies have suggested that the gastric region just below the gastroesophageal junction may have a distinct physiological behavior. We determined whether patients with gastroesophageal reflux disease have abnormal residence of food in the infra-junctional portion of the stomach after ingesting a liquid nutrient meal. Fasted adult patients with reflux disease (N = 11) and healthy volunteers (N = 10) ingested a liquid meal (320 ml; 437 kcal) labeled with 99m technetium-phytate and their total gastric emptying half-time and regional emptying from the stomach infra-junctional region were determined. In 8 patients, episodes of postprandial acidic reflux to the esophagus were measured for 2 h using pH monitoring. There were no differences between reflux patients and controls regarding total gastric emptying time (median: 68 min; range: 39-123 min vs 65 min and 60-99 min, respectively; P > 0.50). Food residence in the infra-junctional area was similar for patients and controls: 23% (range: 20-30) vs 27% (range: 19-30%; P = 0.28) and emptying from this area paralleled total gastric emptying (Rs = 0.79; P = 0.04). There was no correlation between residence of food in the infra-junctional area and episodes of gastroesophageal reflux (Rs = 0.06; P = 0.88). We conclude that it is unlikely that regional motor disturbances involving the infra-junctional region of the stomach play a relevant role in the pathogenesis of acidic gastroesophageal reflux.
Resumo:
New strategies are being devised to limit the impact of renal sclerosis on graft function. Individualization of immunosuppression, specifically the interruption of calcineurin-inhibitors has been tried in order to promote better graft survival once chronic graft dysfunction has been established. However, the long-term impact of these approaches is still not totally clear. Nevertheless, patients at higher risk for tubular atrophy and interstitial fibrosis (TA/IF) development should be carefully monitored for tubular function as well as glomerular performance. Since tubular-interstitial impairment is an early event in TA/IF pathogenesis and associated with graft function, it seems reasonable that strategies directed at assessing tubular structural integrity and function would yield important functional and prognostic data. The measurement of small proteins in urine such as α-1-microglobulin, N-acetyl-beta-D-glucosaminidase, alpha/pi S-glutathione transferases, β-2 microglobulin, and retinol binding protein is associated with proximal tubular cell dysfunction. Therefore, its straightforward assessment could provide a powerful tool in patient monitoring and ongoing clinical assessment of graft function, ultimately helping to facilitate longer patient and graft survival associated with good graft function.