Discrepancies between clinical diagnoses and autopsy findings

Autopsy examination is considered to be an essential element for medical auditing and teaching. Despite the significant progress in diagnostic procedures, autopsy has not always confirmed the clinical diagnosis. In the present study, we compared the diagnosis recorded on medical charts with reports of 96 autopsies performed at the University Teaching Hospital of the Faculdade de Medicina de Botucatu, Botucatu, SP, Brazil, between 1975 and 1982, and of 156 autopsies performed at the same institution between 1992 and 1996. The clinical diagnosis of the basic cause of death was confirmed at autopsy in 77 percent of cases. The percent confirmation fell to 60 percent when the immediate terminal cause of death was considered, and in 25 percent of cases, the terminal cause was only diagnosed at autopsy. The discrepancies between clinical and autopsy diagnosis were even larger for secondary diagnoses: 50 percent of them were not suspected upon clinical diagnosis. Among them, we emphasize the diagnosis of venous thromboses (83 percent), pulmonary embolisms (80 percent), bronchopneumonias (46 percent) and neoplasias (38 percent). Iatrogenic injuries were very frequent, and approximately 90 percent of them were not described in clinical reports. Our results suggest that highly sensitive and specific diagnostic tests are necessary but cannot substitute the clinical practice for the elaboration of correct diagnoses

Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats

Aberrant crypt foci (ACF) in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. In the present study the relationship between a short-term (4 weeks) and medium-term (30 weeks) assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH (40 mg/kg) twice a week for 2 weeks and killed at the end of the 4th or 30th week. ACF were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1 percent methylene-blue whole-mount preparations. ACF were distinguished from normal crypts by their larger size and elliptical shape. The incidence, distribution and morphology of colon tumors were recorded. The majority of ACF were present in the middle and distal colon of DMH-treated rats and their number increased with time. By the 4th week, 91.5 percent ACF were composed of one or two crypts and 8.5 percent had three or more crypts, while by the 30th week 46.9 percent ACF had three or more crypts. Thus, a progression of ACF consisting of multiple crypts was observed from the 4th to the 30th week. Nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. Seven tumors were located in the distal colon and two in the middle colon. No tumor was found in the proximal colon. The present data indicate that induction of ACF by DMH in the short-term (4 weeks) assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks) assay

Atherosclerosis morphology and pathogenesis

Atherosclerosis is a very common and important disease being the most important cause of mortality in Brazil. Indeed, in 1995, 23.3 per cent of deaths, all ages, in our country, were the consequence of atherosclerosis. This percentage grows to 26.3 per cent for S. Paulo and 32.7 per cent for Rio Grande do Sul. Morphologically, there are 3 main types of lesion: fatty streaks, fibrous plaques, and complicated lesions. Fatty streaks are inocuous and occur early in life. In some persons, with age, they change into fibrous plaques that may lead to stenosis. They also may become complicated by erosion, calcification, hemorrhage and thrombosis. Atherosclerosis is initiated by endothelial functional alterations responsible for increase in permeability to macromolecules, adhesion, and migration of monocytes-macrophages and lymphocytes plus recruitment of platelets and smooth-muscle medial cells. Adhesion molecules, cytokines, growth factors, and free radicals are locally synthetized, favoring proliferation of extracellular matrix and progression of the lesion. Experimental, clinical, and epidemiological evidence point to the importance of lipids, mainly cholesterol-rich low-density lipoprotein (LDL), as one of the most important molecules involved in the genesis and progression of atheroclerosis. Patients with a genetic disorder of cholesterol metabolism (familial hyperlipidemia), caused by a decrease in the availability of receptors for LDL, develop severe atherosclerosis early in life. A series of other factors, such as age, diabetes melitus, diet, hypertension, lack of exercise, elevated hemocysteinemia, immunological disorders, and coagulation instability, are related to the progression of atherosclerosis. All of them are capable of altering the endothelium or increasing the offer of LDL. All the above-mentioned factors are systemic; but atherosclerosis lesions are focal, located at preferential sites such as the emergence of colaterals, bifurcations, and curvatures of arteries, all areas in which the laminar flow is disturbed. In these areas shear stress is diminished favoring the prolongation of permanence time of lipid particles, cells, cytokines, growth factors, etc., in the vicinity of the endothelium. Moreover, the endothelium has "sensors" that act as transducers of mechanical forces in biological response. Experimental data demonstrated that the number and quality of adhesion molecules, cytokines, and growth factors synthetized...

Patologia do coraçäo na AIDS. Estudo de 73 necropsias consecutivas / Pahtology of the heart in AIDS. A study of 73 consecutive necropsies

Objetivo - estudar a incidência e a etiologia das lesöes cardíacas na AIDS. Métodos - foram analisadas, retrospectivamente, 72 necropsias consecutivas de portadores de AIDS. Os relatórios das autopsias e os cortes histológicos foram revistos. As lâminas foram coradas por hematoxilina-eosina e quando necessário, estudaram-se,ainda, cortes corados por Ziehl-Nielsen, Gomori Grocott e Gram. Resultados - em nenhum paciente o óbito foi considerado de comprometimento cardíaco. Alteraçöes macro e/ou microspicas foram encontradas em 90 por cento dos casos. Atrofia das fibras cardíacas, associadas ou näo a edema intersticial e lipomatose difusa foi verificada em 51 por cento das autopsias. Infiltrado inflamatório miocárdico foi observado em 38 necropsias em , em 13 casos, um provável agente etiológico foi demonstrado: cryptococcus neoformans em 3 casos e mycobacteria tuberculosis, micobactéria atípica, toxoplasma gondii, trupanosoma cruzi e citomegalovírus em 2 casos cada. Em um paciente foi encontrado metsases de sarcoma de Kaposi e, em 4, endocardite bacteriana. Comprometimento do pericárdio foi verificado em 22 casos. Conclusäo - o exame do coraçào revela a alta incidência de alteraçöes patológicas que podem ser encotradas na AIDS.

Purpose - To study the incidence and the etiology of the cardiac lesions in AIDS patients. Methods - The autopsy protocols and the filled slides of the heart from 73 consecutive AIDS patients were reviewed. There were, at least, 2 slides of each heart stained by haematoxylin-eosin; when indicated, Ziehl Nielsen, Gram and Gomori Grocott stains were used. Results - No cause of death was assigned to the heart. There was involvement of the heart in 66 (90%) cases. Marked atrophy of cardiac fibers with or without lipomatosis was observed in 38 patients. Interstitial infiltrates of myocardium were present in 38 necropsies and in 13 of these cases a probable pathogen was demonstrated: cryptococcus neoforms in three cases and mycobacteria tuberculosis, atypical mycobacteria, toxoplasma gondii, trypanosoma cruzi and cytomegalovirus in two cases each. Bacterial endocarditis was found in 4 autopsies and Kaposi sarcome in one. The pericardium was involved in 22 cases; in 12 there was only non specific mononuclear infiltration. Conclusion - Autopsy examination of the heart from AIDS patients revealed frequent pathologic involvement

The hamster cheek pouch: an immunologically privileged site suitable to the study of granulomatous infections

A bolsa jugal do hamster (BJH) e uma invaginacao da mucosa oral, caracterizada histologicamente como semelhante a pele. Nesse estudo nos descrevemos algumas de suas caracteristicas anatomicas, histologicas e embriologicas e comentamos sobre sua propriedade como local imunologicamente privilegiado, considerando a ausencia de drenagem linfatica e o reduzido numero de celulas de Langerhans ...

Granulomatous reaction in the hamster cheek pouch induced by killed Paracoccidioides brasiliensis

We have studied the role of Paracoccidioides brasiliensis viability in the morphology of paracoccidioidomycotic granulomas in the hamster cheek pouch, an immunologically privileged site. Naive (N=75) and previous senstized (N=50) two-month old male hamsters (Mesocricetus aurathus) were inoculated into the pouch with 5 x 10**5 live or heat-or formalim-killed fungi. Previously sensitized animals presented a positive foot pad tst and immunodiffusion demonstrable antibodies (titer 1/32), at the time of sacrifice, naive animals were always negative for those immunological tests. The histological resultas showed that, like viable P. brasilensis, killed fungi evoke typical epithelioid granulomas in 100 per cent of animal, even in the absence of immunodiffusion or footpad test detectable immune response. The granulomas elicited by killed fungi were devoid of giant cells or a mononuclear cell halo, suggfesting that live proliferating fungi or their products may be involved in these events

Effects of protein deficiency and natural intestinal infection with Giardia lamblia on jejunal intraepithelial lymphocytes in rats of different ages

1. The interaction between experimental protein deprivation and natural intestinal infection by Giardia lamblia was studied in terms of its effects on the intraepithelial lymphocyte (IEL) population and morphology of the jejunal mucosa of rats of different ages. 2. Young, adult and old male Wistar rats received a protein-deficient diet (2 casein) or a control diet (20 casein) for 42 days. Mucosal height and the number of lymphocytes located among 500 consecutive epithelial cells (EC) along the villi or crossing the basement membrane were determined in PAS-stained jejunal fragments. 3. The number of IEL increased progressively with animal age, from 14 to 25 per 100 epithelial cells, with significant differences between age ranges. However, the number of IEL did not differ between control and protein-deficient rats in any of the age groups. The proportion of lymphocytes crossing the basement membrane was approximately two-fold greater in young (2.8/100 EC) and adult (5.8/100 EC) protein-deficient animals than in their respective controls (1.6 and 2.8/100 EC). The intensity of parasite colonization was moderate, from 3 to 5/100 EC and did not differ between groups. The pattern of morphologic changes of jejunal mucosa in protozoal infection did not differ between control and protein-deficient animals in any of the three age groups. 4. We conclude that intestinal infection with Giardia lamblia probably stimulated the local immune response, masking the reduction of the IEL population induced by protein deficiency. The increase in lymphocyte numbers with age may be related to prolonged antigenic stimulation promoted by infection.

Necrose da pequena curvatura gastrica apos vagotomia gastrica proximal por traumatismo da parede gastrica. Estudo experimental em caes. / Necrosis of lesser gastric curvature after proximal gastric vagotomy by traumatic lesion of the gastric wall. Experimental study in dogs

Com o objetivo de estudar a necrose isquemica da pequena curvatura gastrica, apos vagotomia gastrica proximal (VGP), foram operados 36 caes distribuidos por sorteio em dois grupos experimentais: Grupo 1 VGP e Grupo 2 - VGP e traumatismo da parede gastrica. Este tipo de traumatismo foi realizado atraves de uma ligadura, englobando a parede gastrica, com fio de algodao no. 10. Pelos resultados obtidos verificamos que a desvascularizacao determinada pelas ligaduras dos pediculos vasculonervosos, na tecnica de VGP, conserva a irrigacao necessaria a nutricao e manutencao dos tecidos da pequena curvatura gastrica. As ligaduras englobando a parede gastrica podem determinar desde necrose parcial ou total, com perfuracao e peritonite, ate lesoes semelhantes a ulcera cronica. Nos casos de necrose parcial da parede gastrica podem ocorrer tambem lesoes da mucosa gastrica tais como: exulceracao, sufusao hemorragica e convergencia de pregas da mucosa para o local de traumatismo

Insuficiencia hepatica aguda no cobaio. Modelo experimental causado pela injecao de oleato de monoetanolamina. / Acute hepatic insufficiency in guinea pigs. Experimental model caused by monoethanolamina oleate injection

Com o objetivo de produzir um modelo experimental de insuficiencia hepatica aguda (IHA) no cobaio, foram empregados 60 cobaios distribuidos nos seguintes grupos experimentais: a) Grupo Etanolamina - 42 animais submetidos a injecao de 2,5 ml de oleato de monoetanolamina no ducto biliar comun; b) Grupo Controle - 18 animais, nos quais foram injetados 2,5 ml de solucao de NaCI a 0,9% no ducto biliar comum. Foram utilizados para a caracterizacao da IHA os seguintes parametros: quadro clinico, exames laboratoriais (bioquimicos, hematologicos e teste de coagulacao sanguinea) e exame anatomopatologico. A injecao de etanolamina produziu um modelo de insuficiencia hepatica aguda, com a ocorrencia de coma hepatico bem definido em 85,5% dos cobaios nas primeiras 96 horas de evolucao A IHA foi caracterizada pelo quadro clinico tipico de falencia hepatica, alteracoes dos exames bioquimicos (elevacao das bilirrubinas, transaminases e fosfatase alcalina), pelos disturbios da coagulacao sanguinea (alongamento dos tempos de protrombina e tromboplastina parcial ativada e queda do fibrinogenio plasmatico) e pela necrose hepatica macica constatada no exame anatomopatolofico.O modelo experimental desenvolvido pode ser util para o estudo da fisiopatologia da insuficiencia hepatica e para a pesquisa de novos metodos terapeuticos do coma hepatico

Um novo modelo experimental de insuficiencia hepatica aguda. / A new experimental model of acute hepatic insufficiency

E apresentado um novo modelo de insuficiencia hepatica aguda no cobaio, produzido pela injecao intrabiliar de solucao esclerosante. Foram empregados 100 cobaios distribuidos em dois grupos experimentais: 1) Grupo Solucao Esclerosante - 70 animais submetidos a injecao no ducto biliar comum de uma solucao constituida por fenol, acido acetico glacial, glicerina e agua bidestilada na dose de 1 ml. 2) Grupo Controle - 30 animais, noa quais foram injetados 1 ml de solucao de NaCl a 0,9%.A injecao da solucao esclerosante no ducto biliar produziu em 52,9% dos cobaios insuficiencia hepatica aguda caracterizada por: a) quadro clinico bem definido, com evolucao para o coma hepatico de instalacao lenta e longa duracao: b) alteracao dos exames bioquimicos e dos testes de coagulacao sanguinea; c) alteracoes anatomo-patologicas. O modelo experimental desenvolvido pode ser util para o estudo dos mecanismos fisiopatologicos envolvidos na insuficiencia hepatocelular e para a avaliacao de novos metodos para o tratamento do coma hepatico

Irrigacao da pequena curvatura gastrica no cao apos vagotomia gastrica proximal.Avaliacao pela arteriografia pos-morte e pelo estudo das alteracoes histopatologicas. / Irrigation of the lesser gastric curvature in dogs after proximal gastric vagotomy. Evaluation by post-morten arteriography and by the study of histopathologic changes

Com o objetivo de estudar a irrigacao da pequena curvatura gastrica apos vagotomia gastrica proximal, realizou-se arteriografia pos-morte e exame anatomo-patologico em 26 caes, imediatamente apos o termino da cirurgia, no 3o e 7o dia de pos-operatorio. Pelos resultados obtidos concluimos que a desvascularizacao determinada pela vagotomia conserve a irrigacao necessaria a nutricao da parede gastrica. Isto e realizado atraves de amplas anastomoses com os vasos das paredes anterior e posterior da pequena curvatura, nao se observando diferencas quanto a concentracao vascular da pequena curvatura entre estomagos nao operados e vagotomizados. Deste estudo experimental conclui-se que a necrose isquemica da pequena curvatura apos vagotomia gastrica proximal, relatada na clinica, possa ocorrer em consequencia de traumatismo inadvertido da parede gastrica, durante a ligadura dos pediculos vasculo nervosos