Viability of nerve grafts preserved in different storage medium: ultrastructural features

We investigated the ultrastructural organization of transplanted autologous grafts after storage in two different solutions. Male Wistar rats were divided into groups to obtain normal tibial nerves, freshly transplanted nerves, and nerves stored in Wisconsin/Belzer or Collins solution for 24 or 72 hours at 4 °C and transplanted (W1, W3, C1, C3). After storage or transplantation, the specimens were processed for ultrastructural analysis. All grafts showed alterations in collagen fiber organization in the endoneurial space compared to normal nerves. These fibers were more loosely organized among nerve fibers, a finding that was significantly more marked in group C3 compared to groups W1 and W3. Important alterations were also observed in the myelin sheath structure of grafts stored in the two media. These changes were characterized by separation of the lipid lamellae, clearly visible in larger diameter nerve fibers. These findings were more marked and frequent in the C1 and C3 groups compared to the W1 and W3 groups. Ultrastructural analysis showed better preservation of Schwann cells and other elements that support axonal regeneration for grafts stored in Wisconsin/Belzer solution. These results support ongoing studies for the formulation of storage solutions that permit the creation of nerve banks for heterologous transplantation.

Ocorrência de babesiose canina no Município de Uberlândia, Minas Gerais / Incidence of canine babesiosis in Uberlândia, Minas Gerais

Babesia canis é um protozoário intraeritrocítico transmitido pelo carrapato Rhipicephalus sanguineus que acomete principalmente canídeos domésticos e silvestres, causando manifestações clínicas como anorexia, pirexia, hemoglobinúria, esplenomegalia, hemoglobinemia, anemia grave, podendo o animal recuperar-se lentamente ou morrer. O objetivo desta pesquisa foi determinar a ocorrência da doença em Uberlândia – MG e comparar os métodos de esfregaços sangüíneos de ponta de orelha e Reação de Imunofluorescência Indireta (RIFI) no diagnóstico desta enfermidade. Para realização deste trabalho, foram colhidos aleatoriamente soros de 143 cães atendidos no Hospital Veterinário da Universidade Federal de Uberlândia para exame de RIFI enquanto que 772 esfregaços sangüíneos de ponta de orelha foram feitos e corados pelo Giemsa para a pesquisa do hemoparasito. Após a padronização da RIFI, considerou-se positivo soros com diluição igual ou superior a 1:20 e como negativos soros com diluição inferior a 1:20. Dos soros testados, através da RIFI, 51,74% estavam positivos e 48,26% negativos. Dos esfregaços sangüíneos 2,72% eram positivos para babesiose, 87,83% negativos e 9,45% positivos para outros hemoparasitos. Através do teste Qui-quadrado observou-se diferença significativa, em nível de significância 5%, entre os métodos comparados.

Campilobacteriose genital bovina em rebanhos leiteiros com problemas reprodutivos da microrregião de Varginha - Minas Gerais / Bovine genital campylobacteriosis in dairy herds with reproductive problems of the microregion of Varginha, MG, Brazil

The frequency of bovine genital campylobacteriosis (BGC) in 157 cows from nine herds from the microregion of Varginha - Minas Gerais - Brazil was evaluated. Farmers use either artificial insemination and natural breeding after two insemination procedures or natural breeding. The diagnosis of BGC was performed by the direct fluorescent antibody test (DFAT) using vaginal mucus. All studied herds showed C. fetus infected animals and, of 157 animals, 40 (25.5 percent) were positive in DFAT: 7 (26.9 percent) from herds with natural breeding and 33 (25.1 percent) from herds with both artificial insemination and natural breeding after the second-to-third insemination. The high frequency of BGC found in this study shows that this disease is present among herds which have reproductive problems and the use of natural breeding after the second-to-third unsuccessful insemination could be a risk factor for the disease

Marcadores sorológicos da hepatite B em usuários de um Centro de Testagem para o HIV / Serological markers of hepatitis B in users of services at an HIV Testing Center

The objective of this investigation was to study the prevalence of serological markers of hepatitis B and possible risk factors for this disease in a sample of 404 people who attended a Testing and Couseling Center for HIV in the city of Ribeirão Preto, São Paulo State, Brazil. The overall prevalence of serologic hepatitis B markers was 14.6%, equal to that obtained for anti-HBc. HBsAg and anti-HBc IgM showed prevalences of 1%. After adjustment using logistic regression, hepatitis B markers showed association with the following variables: age, place of residence, use of injectable drugs and positivity to anti-HIV. The overall prevalence of human immunodeficiency virus infection was 6.9%. Hepatitis B markers were detected in 55.6% among intravenous drug users and in 42.9% among those who tested positive for HIV, confirming literature findings which indicates high levels of infection in these specific population groups.

Esta investigação objetivou estudar a prevalência de marcadores sorológicos de infecção pelo vírus da hepatite B e analisar possíveis fatores de risco em 404 usuários submetidos à sorologia anti-HIV no Centro de Testagem e Aconselhamento de Ribeirão Preto, SP, Brasil. A prevalência global dos marcadores para o vírus da hepatite B foi de 14,6%, idêntica à encontrada para o anti-HBc, com valores de 1% para o HBsAg e anti-HBc IgM. Após ajuste por regressão logística, os marcadores de infecção do vírus B mostraram associação com as variáveis: idade, local de residência, uso de drogas endovenosas e positividade para o HIV. A prevalência de infecção pelo vírus da imunodeficiência humana foi de 6,9%. Marcadores do vírus B foram detectados em 55,6% dos usuários de drogas endovenosas e em 42,9% dos positivos ao vírus da imunodeficiência humana, confirmando altos índices de infecção nestes grupos específicos.

Serum cytokines in patients with Brazilian pemphigus foliaceus (fogo selvagem)

Pemphigus foliaceus (PF) is characterized by acantholysis determined by IgG4 binding to desmoglein I, a 160-kDa desmosomal glycoprotein. To investigate the immunopathological aspects of Brazilian PF, we determined levels of serum cytokines in patients with PF. Twenty-five patients with PF and a control group consisting of 10 healthy individuals were studied. Serum IL-2, IL-4, IL-5, IL-10, IL-12 and IFN-gamma were measured in the two groups by ELISA. The median concentration of IL-2 was lower in PF patients compared to the control group (0.45 and 9.50 pg/ml, respectively), as also was the concentration of IL-4 (0.26 and 10.16 pg/ml, respectively). The same was observed for IL-5 (7.94 and 15.74 pg/ml, respectively) and for IFN-gamma (5.90 and 8.58 pg/ml, respectively). For IL-10 and IL-12, higher concentrations were observed in PF compared to the control group (IL-10: 24.76 and 20.92; IL-12: 2.92 and 1.17 pg/ml, respectively). Considering the Th1/Th2 paradigm, it seems that a Th2 profile, mainly represented by IL-10, predominates in PF

Implantaçäo de um programa de avaliaçäo terminal do desempenho dos graduados para estimar a eficácia do currículo na Faculdade de Medicina de Ribeiräo Preto / Implantation of program of terminal evaluation of graduating medical students performance to estimate the efficacy of the curriculum in the Faculdade de Medicina de Ribeiräo Preto

Nos últimos cinco anos, um programa de avaliação final do desempenho dos graduandos vem sendo desenvolvido na Faculdade de Medicina de Ribeirão Preto, visando colher dados sobre a eficácia do currículo médico. Objetivo. Descrever as principais etapas de implantação deste programa, bem como as medidas tomadas para superar as dificuldades encontradas. Métodos. A avaliação consiste em uma prova de conhecimento e em exames práticos de habilidades. As provas são elaboradas e aplicadas por docentes das áreas envolvidas sob a supervisão de um grupo coordenador supra-departamental, que avalia todo o programa. Os graduandos participam como voluntários e os resultados são utilizados somente para os fins institucionais propostos. A adesão dos graduandos foi registrada e as impressões dos docentes e dos graduandos sobre o programa foram colhidas por meio de questionários específicos. Resultados. Nos dois primeiros anos a adesão dos graduandos à prova de conhecimento foi superior a 85 por cento, mas o percentual de inscrições nas provas práticas foi de apenas 55 por cento. Além disso, do primeiro para o segundo ano, houve diminuição considerável do grau de empenho dos docentes envolvidos, obrigando medidas corretivas voltadas ao recrutamento dos graduandos, à participação docente e aos métodos de avaliação prática. Em conseqüência, houve aumento notável da adesão dos estudantes que atingiu mais de 90 por cento nos anos seguintes. Houve, também acréscimo considerável do empenho docente, o que garantiu adequado nível de qualidade à avaliação. Conclusão. As medidas tomadas aumentaram a aceitação do programa e a qualidade das provas, permitindo que a avaliação do desempenho dos graduandos traga dados fidedignos sobre a eficácia do currículo.

Inhibitory effect of high [Mg2+]on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+&] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 + OR - 27.2 µm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 + OR - 57.2 µm/s (P<0.05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 + OR - 12.6 µm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 + or - 20.3 µm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3',5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues

Effect of metabolic acidosis on renal tubular sodium handling in rats as determined by lithium clearance

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 ñ 0.13) caused a sustained increase in renal fractional Na+ excretion (267.9 ñ 36.4 per cent), accompanied by an increase in fractional proximal (113.3 ñ 3.6 per cent) and post-proximal (179.7 ñ 20.2 per cent) Na+ and urinary K+ (163.4 ñ 5.6 per cent) 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 ñ 4.6 g) and pair-fed (225 ñ 3.6 g) rats compared to the controls (258 ñ 3.7 g). In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 ñ 0.05 g) compared to the other experimental groups (control, 1.46 ñ 0.05 g; pair-fed, 1.4 ñ 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.

Candidíase em pacientes transplantados renais / Candidiasis in kidney transplant patients

O objetivo do trabalho foi verificar a prevalência de candidíase em transplantados renais. Foram avaliados os prontuários dos pacientes transplantados no Hospital das Clínicas de Ribeirão Preto de fevereiro de 1968 a fevereiro de 1995. Nesse período foram transplantados 620 pacientes. Destes, 87 apresentaram 107 episódios de candidíase. Locais mais acometidos: trato urinário com 55 episódios, trato respiratório com 28, e trato gastrointestinal com 16. O agente etiológico mais freqüente foi C. albicans com 65 casos seguido de C. tropicalis com 12 e C. glabrata com 11 casos. As infecções do trato urinário mostraram incidência maior (61,7%) nos primeiros 6 meses. A maioria se apresentou clínicamente como infecção bacteriana. No trato respiratório, as infecções foram caracterizadas por recuperação do agente no escarro. No trato gastrointestinal, 9/16 episódios foram esofágicos, com epigastralgia, dor retroesternal, às vezes acompanhados de candidíase oral ou odinofagia. Nos outros episódios o agente foi recuperado nas fezes com quadro clínico de gastroenterite. Nas infecções dos tratos urinário e respiratório, houve associação da candidíase com antibioticoterapia prévia (76% e 67% respectivamente), além de infecções bacterianas concomitantes (34% e 64% respectivamente). As infecções por Candida sp tiveram prevalência geral em torno de 14,5%. A localização predominante foi no trato urinário e, em seguida, nos tratos respiratório e gastrointestinal, apresentando alto índice de associação com antibioticoterapia prévia e infecções bacterianas.

The medical records of 620 patients submitted to renal transplant from February 1968 to February 1995 were surveyed for Candida infection. Of these, 87 presented 107 episodes of candidiasis. In 42.9% the infection appeared up to 6 months after the transplant. The most frequent involved sites were: urinary tract, respiratory tract, and gastrointestinal tract. The most frequent etiological agents were: C. albicans, C. tropicalis and C. glabrata. Most urinary tract infections occurred in the first 6 months (61.7%) and manifested clinically as a bacterial infection. In the respiratory tract infections were characterized by isolation of the agent in sputum. In the gastrointestinal infections, 9/16 episodes were esophageal. There were 3 deaths directly related to Candidiasis (one pulmonary and 2 disseminated cases). In the urinary tract, and respiratory tract infections there was association of candidiasis with previous antibiotic treatment (76% and 67%, respectively), and with concomitant bacterial infections (34% and 64%, respectively). The overall prevalence of Candida infections was 14.5%. The predominant location was in the urinary tract (51.0%), followed by the respiratory (26.0%) and gastrointestinal tract (15.0%), with a high rate of association with previous antibiotic treatment and bacterial infections.

Renal tubular sodium handling determined by lithium clearance in partially hepatectomized rats

Decreased renal sodium excretion was observed 2 to 5 days after a two-thirds hepatectomy (Hx) in male Wistar-Hannover rats (200-300 g; N = 10 per group). This fall occurred after normalization of serum liver enzymes by the second day. Hepatocellular dysfunction was demonstrated by a pronounced and transient increase of about 1150 per cent in plasma alanine aminotransferase (ALT), 500 per cent in aspartate aminotransferase (AST), 250 per cent in alkaline phosphatase (ALP) and in serum direct bilirubin levels, which were about six-fold higher than in sham-operated (SH) animals on the first and second days aft hepatectomy. On the basis of the renal clearance of lithium in partially hepatectomized rats, there was a sustained decrease in fractional sodium excretion between the second (SH: 0.053 ñ 0.008 per cent vs Hx: 0.023 ñ 0.008 per cent) and fifth days (SH: 0.040 ñ 0.006 per cent vs Hx: 0.027 ñ 0.009 per cent) post-hepatectomy. This decrease was accompanied by a rise in the absolute (68 ñ 5.2 mumol min-1 100 g body weight-l) an fractional (85.2 ñ 1.4 per cent) proximal sodium reabsorption rates compared to sham-operated rats (53 ñ 3.5 mumol min-1 100 g body weigh-1 and 80.6 ñ 1.1 per cent), but a return to baseline excretion levels was observed by the tenth experimental day. These changes occurred in the absence of any alterations in creatinine clearance, sodium filtered load, hematocrit and total blood volume. Further studies are required to establish the mechanisms of interaction between renal tubule sodium handling and liver function.

Transmission of Chagas' disease through transplanted kidney: occurrence of the acute form of the disease in two recipients from the same donor

Two cases of acute Chagas' disease acquired after renal transplantation are reported. The two patients received the kidney from the same donor. The present paper confirms this form of transmission of Chagas' disease and reinforces the need to exclude kidney donors with Trypanosoma cruzi infection.

Nocardia infection in renal transplant recipient: diagnostic and therapeutic considerations

In the present report the authors discuss the diagnostic difficulties, therapeutic measures and the clinical course of Nocardia infection which occurred among renal transplant recipients at the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo (UH-FRP), from 1968 to 1991. Among 500 individuals submitted to renal transplant, 9 patients developed Nocardiosis at varying times after transplant (two months to over two years). All the patients had pulmonary involvement and their most common symptoms were fever, cough and pleural pain. Dissemination of the process is common and three patients presented cutaneous abscesses, four CNS involvement and one had pericarditis due to Nocardia. The diagnostic is quite difficult since there is no specific clinical picture, concomitant infections are frequent and the microorganism presents slow growth in culture (ranging from four to forty days, in our experience). In this report, three cases were only diagnosed by necropsy. The treatment of choice is a combination of Sulfamethoxazole and Trimethoprim (SMX-TMP). In the present series, overall mortality was 77 (7 cases) and in five of the patients who died the diagnosis was late. All the patients who had CNS involvement died.

Renal sodium handling after noradrenergic stimulation of the lateral hypothalamic area in rats

The participation of specific of special nephron segments in the renal control of sodium handling after adrenergic stimulation was investigated by determining lithium clearance in groups of 5-12 male Wistar rats (230-300 g) microinjected with noradrenaline into the lateral hypothalamic area (LHA). Microinjection of noradrenaline (12.5 to 100.0 nmol/ul) into the LHA promoted a significant decrease in proximal sodium reabsorption (control, 86.5 ñ 1.3; 12.5,81.4 ñ 2.4; 50.0, 75.4 ñ 1.8 and 100.0,77.2 ñ 1.7%) and a dose-related increase in distal sodium reabsorption (control, 13.4 ñ 1.6; 12.5, 18.4 ñ 1.25.0,26.9 ñ 2.9; 50.0,24.1 ñ 2.7; 100.0,22.1 ñ 1.9%) with no significannt changes inm creatinine clearance. Fractional sodium reabsorption after different noradrenaline concentrations was significantly reduced in the proximal nephron sites up to the concentration of 25.0 nmol/ul. Beyond this concentration, a smaller but progressive increase in fraqctional sodium reabsorption was observed in the post-proximal segment. These findings suggest an effective participation of proximal and post-proximal nephrons in natriuresis after lateral hypothalamic noradrenergic stimulation

Reduced anti-mycobacterium tuberculosis antibody response in tuberculosis p0atients with acquired immunodeficiency syndrome

When the sera of patients with tuberculosis were tested for anti-Mycobacterium tuberculosis IgG using an indirect ELISA, the test was positive for 94.1% of the samples from patients not having AIDS (N=51), but for only 37,5% of the samples from patients with AIDS (N=16). False-positive results were obtained for 7,3% of patients not infected with HIV (N=96) and for 4,7% of patients infected with HIV (N=64). In most serum samples obtained from patients with tuberculosis and AIDS after the beginning of specific treatment there was a reduction of the ELISA absorbance at 490 nm with time. These results indicate that serological tests for the detection of anti-M. tuberculosis IgG in patients with AIDS are of limited value for the diagnosis of tuberculosis, most likely as a consequence of the underlying immune defect of the patients

Taquicardia atrial e funçäo renal / Atrial tachycardia and renal function

A taquicardia atrial induzida artificialmente em cäo produziu nas nossas condiçöes, alteraçäo importante da funçäo renal. Essa alteraçäo se manifestou por significativo aumento do volume urinário por minuto (1,3 ñ 0,12 no controle para 3,2 ñ 0,6ml/min no experimental) e da fraçäo de excreçäo de sódio (FENa) (de 2,3 ñ 0,3 no controle para 3,6 ñ 0,5), na presença de queda significante do fluxo sanguíneo renal (317 ñ 30,9 para 232 ñ 26,7 ml/min), sem alterar o ritmo de filtraçäo glomerular (66,1 ñ 6,7 no controle para 70,6 ñ 6,5 ml/min no experimental). Quanto à hemodinâmica sistêmica, observamos queda signficante do débito cardíaco e aumentos significantes da resistência vascular sistêmica e da pressäo de capilar pulmonar. Esses resultados demonstram que possivelmente fatores näo relacionados à hemodinâmica sistêmica, mas relacionados a alteraçöes hormonais, sejam responsáveis por estas alteraçöes

Renal water handling evaluated by lithium clearance following adrenergic and cholinergic stimulation of the lateral hypothalamic area

Male Wistar rats weighing 230-3--g were used to characterize the participation of adrenerg and cholinergic receptors of the lateral hypothalamic area (LHA) in the control of renal water excretion. Since stimulation of adrenergic or cholinergic receptors has no effect on glomerular filtration rate, the antidiuresis and significant delay in urinary flow observed after lateral hypothalamic stimulation with carbachol (CCh) (0.036 ñ 0.005 to o.019 ñ 0.003 µlmin-1 100g body weight-1) and noradrenaline (Nad) (0.024 ñ 0.005 to 0.025 ñ 0.004 µl min-1 100g body weight-1) are secondary to an increase in distal tubular fluid reabsorption (DFR). Data are reported as means ñ SEM for ten rats each group. Tubular water measured by lithim clearance demonstrated that LHA stimulation with CCh (2.8 nmol in 1 µl) and Nad (30.0 nmol in µl) leads to a significant reduction in proximal water reabsorption with CCh, 93.3 ñ 2.6 to 85.4 ñ 1.4%; Nad, 92.7 ñ0.9 to 88.6 ñ 1.3%), with a simultaneous and significant incrase in fluid reabsorption along the post-proximal nephrom segments when compared to control (CNa) (CCh, 6.7 ñ 0.7 to 14.5 ñ 1.1%; Nad 8.2 ñ 0.8 to 11.4 ñ 1.6%) These effects are blocked by muscarinic (atropine, 5 nmol in 1 µl) and alpha-1 adrenoceptors (prazosin, 4 nmol in 1 µl) antagonists. The results indicate the effective participation of the post-proximal nephron in the antidiuresis occurring after cholinergic and adrenergic LHA stimulation

Effect of propranolol and nifedipine on in vitro fluid absorption by the isolated perfused proximal convoluted tubule of the rabbit

The inhibition of fluid absorption (Jv) by the antiarrhythmic and antihypertensive drugs propranolol and nifedipine, which increase cytosolic Ca*+ concentration, was studied using the isolated rabbid proximal convoluted tubule perfused in vitro. Proximal convuluted tubules were perfused and bathed with a modified Krebs-Henseleit solution containing bovine serum albumin. Jv was measured after a 30-min control period, after 40 min with eithe 0.1 mM propranolol or 1.0 mM mifedipine on the peritubular side and after a 40-min recovery period. Both drugs inhibited Jv (58% propranolol, and 21% nifedipine) The 40-min recovery period was sufficient to reserve the effect of nifedipine, but propranolol-treated tubules (N=6) only reached 78% of the control Jv value. These results demonstrate that antiarrhythmic and anthypertensive drugs are powerful inhbitors of net fluid absorption by exerting a direct effect on proximal or distal tubule cells, thus acting like "local diuretics"