Evaluation of WGA and Concanavalin A (Con A) lectin as biomarkers of hepatosplenic schistosomiasis in human biopsies with no evidence of egg-granuloma system

Introduction: Colonic lesions are predominant in patients with schistosomiasis. However, carbohydrate alterations in colonic schistosomiasis remain unclear. Lectin-ligands allow us to identify changes in the saccharide patterns of cells. Methods: Biopsies of descending and rectosigmoid colon of patients were submitted to WGA and Con A lectin histochemistry. Results: WGA stained stroma and gland cells of descending colon and rectosigmoid tissues in a granular strong cytoplasmatic pattern in schistosomiasis specimens differing from normal control and Con A failing to recognize all samples analyzed. Conclusions: WGA ligands are expressed differently in patients with hepatosplenic schistosomiasis and no evidence of egg-granuloma system.

The indeterminate form of human chronic Chagas' disease: a clinical epidemological review

Data on the epidemiology and the natural history of the indeterminate form of human chronic Chagas' disease (IFCCD) are discussed, revealing its great importance in endemic areas of Brazil. The work shows that IFCCD presents a gradual and very slow course, causing a benign picture in the studied patients. Evolution patterns, prognostic and anatomopathological features are also discussed. For practical purposes, the classical concept of IFCCD proved to be simple, operational and consistent, It is defined by the absence of symptoms and clinical findings in chronic infected patients with positive serology and/or parasitological examinations for Trypanosoma cruzi coupled with normal electrocardiographic and radiological exams (heart, oesophagus and colon X-Rays). If a patient is submitted to more rigorous and sophisticated tests, these can reveal some alterations, generally small ones and unable to interfere with the prognosis of the infection. It is suggested that research lines specially related to the evolution ary factors and immunological involvement during this phase be adopted.

The FML (Fucose Mannose Ligand) of Leishmania donovani: a new tool in diagnosis, prognosis, transfusional control and vaccination against human kala-azar

The Fucose-Mannose Ligand (FML) of Leishmania donovani is a complex glycoproteic fraction. Its potential use as a tool for diagnosis of human visceral leishmaniasis was tested with human sera from Natal, Rio Grande do Norte, Brazil. The FML-ELISA test, showed 100% sensitivity and 96% specificity, identifying patients with overt kala-azar (p < 0.001, when compared to normal sera), and subjects with subclinical infection. More than 20% apparently healthy subjects with positive reaction to FML developed overt kala-azar during the following 10 months. In the screening of human blood donnors, a prevalence of 5% of sororeactive subjects was detected, attaining 17% in a single day. The GP36 glycoprotein of FHL is specifically reconized by human kala-azar sera. The immunoprotective effect of FML on experimental L. donovanii infection was tested in swiss albino mice. The protection scheemes included three weekly doses of FML, supplemented or not with saponin by the subcutaneous or intraperitoneal routes and challenge with 2x 10(7) amastigotes of Leishmania donovani. An enhancement of 80.0 % in antibody response (p<0.001) and reduction of 85.5 % parasite liver burden (p<0.001) was detected in animals immunized with FML saponin, unrespectivety of the immunization route.

Immunodiagnosis of human neurocysticercosis by using semi-purified scolex antigens from Taenia solium cysticerci

Crude antigen and semi-purified proteins from scolices of Taenia solium cysticerci were evaluated for the immunodiagnosis of human neurocysticercosis neurocysticercosis. Semi-purified proteins obtained by electrophoresis on polyacrylamide gel and by electroelution were tested by means of the immunoenzymatic reaction against sera from normal individuals and from patients with neurocysticercosis or other parasitic diseases. The 100kDa protein provided 100% sensitivity and specificity in the immunodiagnosis. When 95 or 26kDa proteins were used, 95 and 100% sensitivity and specificity were obtained, respectively. The assays involving crude antigen and sera from normal individuals or from patients with neurocysticercosis, diluted to 1:256, gave excellent agreement with those in which 100, 95 or 26kDa proteins were tested against the same serum samples diluted to 1:64. (Kappa: 0.95 to 1.00). Crude scolex antigen may be useful for serological screening, while 100, 95 or 26kDa protein can be used in confirmatory tests on neurocysticercosis-positive cases.

Further evidence of spontaneous cure in human Chagas disease

An acute case of Chagas disease was studied in 1944, with clinical and laboratory follow-up until 2007, in Bambuí, Minas Gerais, Brazil. A five-year-old girl living in a rural hut that was highly infested with Triatoma infestans presented a febrile clinical condition compatible with the acute form of trypanosomiasis. She presented a positive thick blood smear, but never again showed serological and/or parasitological evidence of Trypanosoma cruzi infection, on several occasions. This patient never received any specific treatment and, to this day, she remains completely asymptomatic, with normal findings from clinical, electrocardiographic, X-ray and echocardiographic examinations.

Hydrophobic fraction of Taenia saginata metacestodes, rather than hydrophilic fraction, contains immunodominant markers for diagnosing human neurocysticercosis

INTRODUCTION: Considering that alternative antigens for diagnosing neurocysticercosis continue to be a challenge because of the increasing difficulty in obtaining parasites from naturally infected pigs for preparation of Taenia solium homologous antigen, the aim of the present study was to evaluate the detergent (D) and aqueous (A) fractions from saline extract of Taenia saginata metacestodes for diagnosing neurocysticercosis. METHODS: Taenia saginata was obtained from naturally infected bovines in the Triângulo Mineiro region, State of Minas Gerais, Brazil. The carcasses came from cold storage units and had been slaughtered in accordance with the inspection technique recommended by the Federal Inspection Service. The D and A fractions were obtained by using Triton X-114 (TX-114). Serum samples were obtained from 40 patients with a diagnosis of neurocysticercosis, 45 with other parasitic diseases and 30 from apparently normal individuals. IgG antibody levels were evaluated using the ELISA and immunoblotting assays. RESULTS: The ELISA sensitivity and specificity were 95% and 73.3%, when using saline extract; 95% and 82.6% for the D fraction; and 65% and 61.3% for the A fraction, respectively. The immunoblotting assay confirmed the ELISA results, such that the D fraction was more efficient than the other extracts, and the 70-68kDa component was immunodominant among neurocysticercosis patients. CONCLUSIONS: These results demonstrated that the D fraction from Taenia saginata metacestodes obtained using TX-114 can be used as a heterologous antigenic fraction in the immunoblotting assay for serologically diagnosing human neurocysticercosis, given its ability to select immunodominant antigens.

Antituberculosis drug-induced hepatotoxicity: a comparison between patients with and without human immunodeficiency virus seropositivity

INTRODUCTION: The prevalence and risk factors for rifampin, isoniazid and pyrazinamide hepatotoxicity were evaluated in HIV-infected subjects and controls. METHODS: Patients with tuberculosis (30 HIV positive and 132 HIV negative), aged between 18 and 80 years-old, admitted to hospital in Brazil, from 2005 to 2007, were selected for this investigation. Three definitions of hepatotoxicity were used: I) a 3-fold increase in the lower limit of normal for alanine-aminotransferase (ALT); II) a 3-fold increase in the upper limit of normal (ULN) for ALT, and III) a 3-fold increase in the ULN for ALT plus a 2-fold increase in the ULN of total bilirubin. RESULTS: In groups with and without HIV infection the frequency of hepatotoxicity I was 77% and 46%, respectively (p < 0.01). Using hepatotoxicity II and III definitions no difference was observed in the occurrence of antituberculosis drug-induced hepatitis. Of the 17 patients with hepatotoxicity by definition III, 3 presented no side effects and treatment was well tolerated. In 8 (36.4%) out of 22, symptoms emerged and treatment was suspended. Alcohol abuse was related to hepatotoxicity only for definition I. CONCLUSIONS: Depending on the definition of drug-induced hepatitis, HIV infection may or may not be associated with hepatotoxicity. The impact that minor alterations in the definition had on the results was impressive. No death was related to drug-induced hepatotoxicity. The emergence of new symptoms after initiating antituberculosis therapy could not be attributed to hepatotoxicity in over one third of the cases.

Liver fibrosis progression in HIV/hepatitis C virus coinfected patients with normal aminotransferases levels

INTRODUCTION: Approximately 30% of hepatitis C virus (HCV) monoinfected patients present persistently normal alanine aminotransferase (ALT) levels. Most of these patients have a slow progression of liver fibrosis. Studies have demonstrated the rate of liver fibrosis progression in hepatitis C virus-human immunodeficiency virus (HCV-HIV) coinfected patients is faster than in patients infected only by HCV. Few studies have evaluated the histological features of chronic hepatitis C in HIV-infected patients with normal ALT levels. METHODS: HCV-HIV coinfected patients (HCV-RNA and anti-HIV positive) with known time of HCV infection (intravenous drugs users) were selected. Patients with hepatitis B surface antigen (HBsAg) positive or hepatitis C treatment before liver biopsy were excluded. Patients were considered to have a normal ALT levels if they had at least 3 normal determinations in the previous 6 months prior to liver biopsy. All patients were submitted to liver biopsy and METAVIR scale was used. RESULTS: Of 50 studied patients 40 (80%) were males. All patients were treated with antiretroviral therapy. The ALT levels were normal in 13 (26%) patients. HCV-HIV co-infected patients with normal ALT levels had presented means of the liver fibrosis stages (0.77±0.44 versus 1.86±1.38; p<0.001) periportal inflammatory activity (0.62±0.77 versus 2.24±1.35; p<0.001) and liver fibrosis progression rate (0.058±0.043 fibrosis unit/year versus 0.118±0.102 fibrosis unit/year) significantly lower as compared to those with elevated ALT. CONCLUSIONS: HCV-HIV coinfected patients with persistently normal ALTs showed slower progression of liver fibrosis. In these patients the development of liver cirrhosis is improbable.

Normal bone density in male pseudohermaphroditism due to 5alpha- reductase 2 deficiency

Bone is an androgen-dependent tissue, but it is not clear whether the androgen action in bone depends on testosterone or on dihydrotestosterone. Patients with 5alpha-reductase 2 deficiency present normal levels of testosterone and low levels of dihydrotestosterone, providing an in vivo human model for the analysis of the effect of testosterone on bone. OBJECTIVE: To analyze bone mineral density in 4 adult patients with male pseudohermaphroditism due to 5alpha-reductase 2 deficiency. RESULTS: Three patients presented normal bone mineral density of the lumbar column (L1-L4) and femur neck, and the other patient presented a slight osteopenia in the lumbar column. CONCLUSION: Patients with dihydrotestosterone deficiency present normal bone mineral density, suggesting that dihydrotestosterone is not the main androgen acting in bone.

Alterações cutâneas do cão no Kala-Azar sul-americano

According to E. Chagas (1938), South-American Kala Azar is a widespread disease from the jungle, several cases being reported from North Brazil (Estado do Pará: Marajó Island, Tocantins and Gurupi river valleys; Estados do Piauí and Ceará: coast and hinterland). Other cases were found in Northeast Brazil (Estados de Pernambuco, Alagôas and Sergipe: coast and hinterland; Estado da Bahia: hinterland). A few cases were described from Estado de Mato-Grosso (Brazil), Provincia de Salta and Território do Chaco (Argentine), and Zona contestada do Chaco (Paraguai-Bolívia). A well defined secondary anemia associated with enlargement of the liver and spleen are the chief symptoms. Death usually occurs in cachexia and with symptoms of heart failure. Half the patients were children aged less than ten years (CHAGAS, CASTRO & FERREIRA, 1937). Quite exhaustive epidemiological researches performed by CHAGAS, FERREIRA, DEANE, DEANE & GUIMARÃES (1938) in Municipio de Abaeté (Estado do Pará, Brazil) gave the incidence of 1.48% for the natural infection in human, 4.49% in dogs, and 2.63% in cats. The infection was arcribed (CUNHA & CHAGAS, 1937) to a new species of Leishmania (L. chagasi). Latter CUNHA (1938) state, that it is identical to L. infantum. ADLER (1940) found that so far it has been impossible to distinguish L. chagasi from L. infantum by any laboratory test but a final judgment must be reserved until further experiments with different species of sandflies have been carried out. Skin changes in canine Kala Azar were signaled by many workers, and their importance as regards the transmission of the disease is recognized by some of them (ADLER & THEODOR, 1931, 2. CUNHA, 1933). Cutaneous ulcers in naturally infected dogs are referred by CRITIEN (1911) in Malta, by CHODUKIN & SCHEVTSCHENKO (1928) in Taschkent, by DONATIEN & LESTOCQUARD (1929) and by LESTOCQUARD & PARROT (1929) in Algeria, and by BLANC & CAMINOPETROS (1931) in Greece. Depilation is signaled by YAKIMOFF & KOHL-YAKIMOFF (1911) in Tunis, by YAKIMOFF (1915) in Turkestan. Eczematous areas or a condition described as "eczema furfurace" is sometimes noted in the areas of depilation (DONATIEN & LESTOCQUARD). The skin changes noticed by ADLER & THEODOR (1932) in dogs naturally infected with Mediterranean Kala Azar can be briefly summarized as a selective infiltration of macrophages around hair follicles including the sebaceous glands and the presence of infected macrophages in normal dermis. The latter phenomenon in the complete absence of secondary infiltration of round cells and plasma cells is the most striking characteristic of canine Kala Azar and differentiates it from L. tropica. In the more advanced stages the dermis is more cellular than that of normal dogs and may even contain a few small dense areas of infiltration with macrophages and some round cells and polymorphs. The external changes, i. e., seborrhea and depilation are roughly proportional to the number of affected hair follicles. In dogs experimentally infected with South-American Kala Azar the parasites were regularly found in blocks of skin removed from the living animal every fortnight (CUNHA, 1938). The changes noticed by CUNHA, besides the presence of Leishmania, were perivascular and diffuse infiltration of the cutis with mononuclears sometimes more marked near hair follicles, as well as depilation, seborrhea and ulceration. The parasites were first discovered and very numerous in the paws. Our material was obtained from dogs experimentally infected by Dr. A. MARQUES DA CUNHA< and they were the subject of a previous paper by CUNHA (1938). In this study, however, several animals were discarded as it was found that they did develop a superimposed infection by Demodex canis. This paper deals with the changes found in 88 blocks of skin removed from five dogs, two infected with two different canine strains, and three with two distinct human strains of South-American Kala Azar. CUNHA'S valuable material affords serial observations of the cutaneous changes in Kala Azar as most of the blocks of skin were taken every fortnight. The following conclusions were drawn after a careful microscopic study. (1) Skin changes directly induced in the dog by the parasites of South-American Kala Azar may b described as an infiltration of the corium (pars papillaris and upper portion of the reticular layer) by histocytes. Parasites are scanty, at first, latter becoming very numerous in the cytoplasm of such cells. Sometimes the histocytes either embedding or not leishman bodies appear as distinct nodes of infiltration or cell aggregations (histocytic granuloma, Figs. 8 and 22) having a perivascular distribution. The capillary loops in the papillae, the vessels of the sweat glands, the subpapillary plexus, the vertical twigs connecting the superficial and deep plexuses are the ordinary seats of the histocytic Kala Azar granulomata. (2) Some of the cutaneous changes are transient, and show spontaneous tendency to heal. A gradual transformation of the histocytes either containing or not leishman bodies into fixed connective tissue cells or fibroblasts occut and accounts for the natural regression just mentioned. Figs. 3, 5, 18, 19 and 20 are good illustrations of such fibroblastic transformation of the histocytic Kala Azar granulomata. (3) Skin changes induced by the causative organism of South-American Kala Azar are neither uniform nor simultaneous. The same stage may be found in the same dog in different periods of the disease, and not the same changes take place when pieces from several regions are examined in the same moment. The fibroblastic transformation of the histocytic granulomata marking the beginning of the process of repair, e. g., was recognised in dog C, in the 196th as well as in the 213rd (Fig. 18) and 231st (Fig. 19) days after the inoculation. (4) The connective tissue of the skin in dogs experimentally infected with South-American Kala Azar is overflowed by blood cells (monocytes and lymphocytes) besides the proliferation in situ of undifferentiated mesenchymal cells. A marked increase in the number of cells specially the "ruhende Wanderzellen" (Figs. 4 and 15) is noticed even during the first weeks after inoculation (prodomal stage) when no leishman bodies are yet found in the skin. Latter a massive infiltration by amoeboid wandering cells similar to typical blood monocytes (Fig. 21) associated to a small number of lymphocytes and plasma cells (Figs. 9, 17, 21, and 24) indicates that the emigration of blood cells...

Toxoplasmose congênita

We had the opportunity to study 6 cases of the congenital form of toxoplasmosis, found in a series of 1200 necropsies of fetuses and newborn babies, realized at 3 different hospitals in Rio de Janeiro, Brazil. Among the 6 cases, 4 were premature babies liveborn at the 6th-8th gestational month and 2 were stillborn (1 premature and 1 at term). In all those cases, the diagnosis was based in the detection of the parasite in tissues and in one case it was even isolated the Toxoplasma from the necrotic material found in the cranial cavity. This strain of Toxoplasma, pathogenic to pigeons, to guinea pigs and to mice, is preserved by successive transfers in mice. Some facts observed in those cases present an interest not only strictly anatomic but also have certain value for the better acknowlegment of the disease. First, we want to call the attention to the presence of a sudden high fever, during or just before pregnancy in the 4 cases in which the maternal anamnesis was perfectly studied; this fever that was preceded by a normal beginning of pregnancy, had relatively rapid remission, but in 2 cases was immediately followed by uterine bleeding and premature delivery, although the puerperium had been apparently normal. It is known that are normal the subsequent children of the mothers that delivered a baby with toxoplasmosis and that several women have normal babies before the toxoplasmotic one. We believe that the fever observed in our cases could be indicative of the beginning of maternal infection and those are the reasons why we emphasize the need of careful anamnesis, specially in the cases actually diagnosed as inapparent infection. Another fact to notice is that in 5 of our cases the event premature delivery happened always between the 6th and the 8th months of pregnancy, and the only term fetus was delivered in advanced stage of maceration. The above mentioned facts could agree with the opinion of FRENKEL (1949), when he declared that "primary infection of the pregnant mother appears more likely to be the commoner mode of fetal toxoplasmic infection", but they would disagree with WEINMAN (1952) who believes that the transmission of Toxoplasma to the fetus is more frequent through a pregnant woman with chronic disease and who says "that infection contracted during pregnancy may and probably does happen from time to time"...Still in connection with the transmission of toxoplasmosis, we want to note the verification of inflammatory lesions in the placental villi and in the umbilical cord in 3 of the 4 cases in which such organs were examined at the microscope. In the case n. 1, we found several pseudocysts of Toxoplasma in the placenta, and the fibroblasts of Wharton's jelly were particularly rich in isolated forms and in colonies of Toxoplasma; the easy multiplication of the parasite in that tissue calls the attention and even suggests its utilisation for Toxoplasma's cultivation. The confirmation of Toxoplasma in human placenta was made only recently by CRISTEN et al. (1951) and by NEGHME et al. (1952), in Chile; it is not frequent in the literature, what gives some value to our present verification. Another observation was that provided by the case n. 6. This baby, a premature one of the 6th month, was 14 days old and-died with signs of respiratory disease, the causa mortis have been pneumonia. At the necropsy, we found no gross change that suggested toxoplasmosis, except the presence of some small necrotic focuses in the cerebral nervous substance around the ventricles. As a matter of fact, there was no enlargement of spleen or liver and neither leptomeningitis nor hydrocephalus. Such focuses were attributed to possible anoxia and in fact they are extremely similar to anoxial softenings, even when they are examined at the microscope; its structure composed of a central necrotic zone, surrounded by proliferated neuroglia and by a variable deposit of calcium salts, closely simulated the anoxial softenings, when the microscopical examination is based in the common histological preparations (hematoxilin-eosin, etc.). But when we examine preparations by the Giemsa or by the periodic acid-Schiff methods, we will note the presence of Toxoplasma, with its typical aspect or a little changed by degeneration. When we describe this observation, we wish to evidence the need of the search of Toxoplasma and closed parasites, in the cases of supposed pure anoxial softenings of nervous substance, in children. The frequency with which the congenital toxoplasmosis was anatomically verified should be emphasized, although the disease had not been clinically suspected, and it should be borne in mind that the second case of toxoplasmosis reported in the world was observed in Brazil by MAGARINOS TORRES; this case was the first to be described of the generalized congenital form of the infection, i. e. with myocardial lesions and parasites in skeletal muscles and skin.

Characterization of human heterophil hemolysins induced by Schistosoma mansoni infection

Heterophil antibodies could be detected in sera from normal or from patient with chronic schistosomiasis. Their hemolytic activities depend on the integrity of the complement classic pathway. The heterophil antibodies from patient sera presented a higher specificity for Schistosoma mansoni antigen preparations than those detected in normal sera. Most of the hemolytic activity observed in normal sera can be destroyed at 56ºC for 4 min. On the other hand, about 80% of the sera from infected patients are partially or totally resistant to this heat-treatment. The hemolytic activities of sera were eluted from a gel filtration column in different fractions of the first peak.

Cytokines and dysregulation of the immune response in human malaria

The dysregulation of the immune response by malaria parasite has been considered as a possible constraint to the effectiveness of malaria vaccination. In spite of the important role interleukin-I (IL-1) in malaria are lacking. We found that only 2 out of 35 subjectswith acute malaria showed increased levels of serum IL-1 alpha by enzyme immunoassay. To assess whether IL-1 could interfere with T- lymphocyte responses, blood mononuclear cells from patients infected with Plasmodium falciparum, P. vivax, or healthy subjects were cultured with phytohemagglutinin, and lymphocyte proliferation measured 72h later by 3H-thymidine incorporation. Our data showed that T-lymphocyte responses are depressed both in P. falciparum (10,500 ñ 2,900) and P. vivax malaria (13,000 ñ 3,300), as compared to that of healthy individuals (27,000 ñ 3,000). Addition of IL-1 partially reserved depression of malaria lymphocytes, but had no effect on normal cells. On the other hand, T-lymphocytes from malaria infected-subjects presented a minimal decrease in proliferation, when cultured in the presence of exogenous PGE2. These data indicate the occurrence of two defects of immunoregulation in malaria: a deficiency of IL-1 production by monocytes/macrophages, and an increased resistance of lymphocytes to the antiproliferative effect of PGE2.

Pseudomonas aeruginosa adhesion to normal and injured respiratory mucosa

Human nasal polyps outgrowth culture were used to study the adhesion of Pseudomonas aeruginosa to respiratory cells. By transmission electron microscopy, bacteria associated with ciliated cells were identified trapped at the extremities of cilia, usually as aggregates of several bacterial cells. They were never seen at the interciliary spaces or attached along cilia. Bacteria were also seen to adhere to migrating cells of the periphery of the outgrowth culture. Using a model of repair of wounded respiratory epithelial cells in culture, we observed that the adhesion of P. aeruginosa to migrating cells of the edges of the repairing wounds was significantly higher than the adhesion to non-migrating cells and that adherent bacteria were surrounded by a fibrocnectin-containing fibrillar material The secretion of extracellular matrix components is involved in the process of epithelium repair following injury. To investigate the molecular basis of P. aeruginosa adhesion to migrating cells, bacteria were treated with a fibronectin solution before their incubation with the respiratory cells. P. aeruginosa treatment by fibronectin significantly increased their adhesion to migrating cells. Accordingly, we hypothesize that during cell migration, fibronectin secreted by epithelial cells may favour P. aeruginosa adhesion by establishing a bridge between the bacteria and the epithelial cell receptors. Such a mechanism may represent a critical step for P. aeruginosa infection of healing injured epithelium.

Human B19 parvovirus infetion: an example of multiple pathogenic effects determined by differences in host susceptibility

B19 infection offers some general lessons about human viruses and their possible effects on the human host, as follows: (1) Ubiquitous apparently benign viruses may have severe effects on a compromissed host. The virus may be invariable but the host can have diverse susceptibilities. (2) B19 and some other human viruses (through for none is the evidence so clear as for B19) have narrowly targetted effects. The host cell of B19 is a specialised progenitor of mature red cells: impairment of the function of this cell by B19 may cause profound anaemia. (3) The 'normal'host response to B19 may also cause disease, though this is slef limiting. (4) The effects of malfunction of the virus'target cell are exacerbated when the immune response is impaired by congenital or acquired immunodeficiency, immunosupressive therapy or, in the case of the fetus, developmental immaturity that allows the virus to persist.