Immune Response in Human Visceral Leishmaniasis: Analysis of the Correlation Between Innate Immunity Cytokine Profile and Disease Outcome

We investigated the cytokine profile of cells of the innate immune response and its association with active (ACT), asymptomatic (AS) and cured (CUR) human visceral leishmaniasis (VL), as well as noninfected (NI) subjects. The frequency of cytokine-producing cells was determined after short-term in vitro incubation of whole peripheral blood samples with soluble Leishmania antigen (SLA). Our data demonstrated a predominant type 2 cytokine profile in NI and ACT. In NI, we observed an increase of IL-4+ neutrophils, IL-10+ eosinophils besides a decrease of tumour necrosis factor (TNF)-alpha+ eosinophils/monocytes. Yet in ACT, we observed an increase of IL-4+ neutrophils and natural killer (NK) cells and IL-10+ monocytes, a reduced frequency of IL-12+ and IFN-gamma+ eosinophils and lower levels of TNF-alpha+ and IL-12+ monocytes. AS presented a mixed profile, characterized by an increase of IFN-gamma+ neutrophils/eosinophils and NK cells, of IL-12+ eosinophils/monocytes, as well as increase of IL-4+ neutrophils and NK cells and IL-10+ eosinophils/monocytes. In contrast, CUR was characterized by a type 1 response with an increase of IFN-gamma+ neutrophils/eosinophils and NK cells, associated with an increase in IL-12+ monocytes. In conclusion, we show a correlation between innate immune cytokine patterns and clinical status of VL, suggesting that these cells, in addition to other factors, may contribute to the cytokine microenvironment in which Leishmania-specific T cells are primed and to disease outcome.

Aspectos da ecologia e do comportamento de flebotomíneos em área endêmica de leishmaniose visceral, Minas Gerais

O comportamento e hábitos alimentares de algumas espécies da flebotomíneos têm sido útil na compreensão da epidemiologia das leishmanioses. No município de Porteirinha (MG), foram realizadas capturas mensais sistematizadas utilizando-se 28 armadilhas luminosas tipo CDC, durante o período de janeiro a dezembro de 2002. Foram capturadas 14 espécies de flebotomíneos, totalizando 1.408 exemplares. De acordo com o ambiente, os resultados obtidos mostraram que o peridomicílio apresentou a maior (53,3%) porcentagem dos espécimens encontrados na região, embora parte (46,7%) da fauna também tenha sido encontrada no intradomicílio. O repasto sanguíneo de 38 fêmeas de Lutzomyia longipalpis, provenientes do campo, foi identificado através da reação de precipitina. Os resultados indicam que Lutzomyia longipalpis foi a espécie predominante (65,1%), mostrando-se oportunista, podendo sugar uma ampla variedade de vertebrados.

Very low prevalence of hepatitis C virus infection in rural communities of northeastern Brazil with a high prevalence of schistosomiasis mansoni

The association of hepatitis C virus infection and the hepatosplenic form of schistosomiasis mansoni has been claimed to result in the concomitant evolution of the two pathologies, with a poor prognosis due to aggravated liver disease. Recently, however, some authors have begun to reject the hypothesis of a higher susceptibility of hepatosplenic schistosomal patients to HCV. The aim of the present transverse study carried out between July and August 1990 was to determine the possible association between SM and HCV markers in residents of Catolândia, Bahia State. Anti-HCV markers were assayed by ELISA-II and RIBA-II in serum samples obtained from 1,228 residents (85.8%). The anti-HCV antibody (ELISA-II) was positive in six (0.5%) individuals, eight (0.6%) cases were inconclusive and 1,214 (98.9%) were negative. However, only in one ELISA-positive serum sample (0.08%) were antibodies confirmed by RIBA-II, while two other samples assayed by RIBA-II were indeterminate. These three patients presented the hepatointestinal form of SM during the follow-up period (1976 to 1996). In conclusion, no association was observed between HCV and SM in the endemic area studied, especially among patients with the hepatosplenic form of the disease.

[A comparison of two antigens for Montenegro skin test]

Intradermal reactions were performed in 399 individuals by using, simultaneously, the antigen produced by both the Universidade Federal de Minas Gerais and Fundação Instituto Oswaldo Cruz. Each of these antigens was manufactured with promastigotes of Leishmania (L) amazonensis (IFLA/BR/67/PH8). The Fundação Oswaldo Cruz antigen caused a larger number of positive reactions. Discordant reactions occurred in 22% of the individuals.

Influência da parasitemia na evolução da doença de Chagas crônica

Estudou-se clínica e parasitologicamente, durante 13 anos, 190 indivíduos com infecção chagásica objetivando investigar a relação entre parasitemia e a evolução da doença de Chagas crônica. Comparou-se a parasitemia de 56 indivíduos xenopositivos e 134 xenonegativos, em 1988/91 com a evolução clínica encontrado-se 22 (39,3%) e 50 (37,3%), respectivamente, com evolução progressiva. Estratificou-se a parasitemia em 1988/91, em alta, média e baixa e a correlação clínica mostrou que 5 (62,5%), 10 (41,7%) e 57 (36.1%) indivíduos, respectivamente, apresentaram evolução progressiva, sem diferença estatística significante, (p>0,05). No período de 1976/91, houve 20 pacientes com parasitemia constante e 59 sem parasitemia, observando-se evolução progressiva em 6 (30%) e 17 (28,8%), respectivamente. Houve seis pacientes com alta parasitemia e, 59 sem parasitemia, verificado-se que 3 (50%) e 17 (28,8%), respectivamente, apresentaram evolução progressiva, sem diferença estatística significante, (p>0,05). As médias das idades daqueles com alta, média e baixa parasitemias foram 39,6; 45,3 e 41,5 anos, respectivamente, (p>0,05). As médias das idades dos pacientes com evolução progressiva, inalterada e regressiva foram respectivamente, 46,4; 39,8 e 32,6 anos, com diferença estatística significante entre aqueles com evolução progressiva e regressiva, (p<0,05). Sugere-se que a alta parasitemia não influenciou na evolução da doença crônica.

Comparative clinical and ultrasound study of egg-negative and egg-positive individuals from Schistosoma mansoni low morbidity endemic areas, and hospitalized patients with hepatosplenic disease

Two hundred and twenty three subjects from a Schistosoma mansoni low morbidity endemic area and nine hospitalized hepatosplenic patients were submitted to stool test and clinical examination and abdomen ultrasound assessments. According to stool examination and ultrasound results, they were grouped as follows: G1 -- 63 Schistosoma mansoni egg-negative individuals; G2 -- 141 egg-positive patients and without evidence of periportal fibrosis; G3 -- 19 egg-positive patients with periportal echogenicity (3-6 mm); and G4 -- 9 hepatosplenic patients with periportal echogenicity (> 6 mm). Hepatomegaly detected by physical examination of the abdomen evaluated in the midclavicular line was verified in G1, G2 and G3, respectively, in 11.1, 12.1 and 26.3%. In G1, G2 and G3, periportal thickening occurred only in schistosomal patients (8.5%). Mild pathological alterations in patients that cannot yet be detected by clinical examination were detectable in the liver by ultrasound and can be due to fibrosis. The degree of mild periportal fibrosis was diminished in 57.9% of patients 12 months after treatment of schistosomiasis with oxamniquine. At ultrasonography, the mean liver left lobe measurement of G3 was larger than that of G1, and that of G4 larger than that of G1 and G2. The mean size of the spleen of G4 was significantly larger than that of the other three groups, and that of G3 larger than that of G1 and G2.

Phlebotomine sand flies in Porteirinha, an area of American visceral leishmaniasis transmission in the State of Minas Gerais, Brazil

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmaniasis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predominant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed.

The role of the scientific research in the control of schistosomiasis in endemic areas

The way the researches established the lines of direction for considering fight against schistosomiasis on the double aspect of transmission and morbidity control is outstanding. Chemotherapy in the morbidity control is emphasized. The research priorities for schistosomiasis control are mentioned.

Azithromycin in the treatment of mucosal leishmaniasis

This report describes three elderly patients with mucosal form of American tegumentary leishmaniasis associated with chronic cardiopathy. Due to the known toxicity of classical drugs with activity against Leishmania sp., the patients received three oral courses of azithromycin therapy in single 500 mg daily dose during ten days, every other month. All lesions healed after the third series. One of the patients relapsed and a new series of azithromycin was prescribed. Azithromycin may be an alternative drug for the treatment of leishmaniasis in special situations due to its optimal mucosal and intraphagocyte concentration, single daily posology, high tolerance and oral administration. The mechanism of this drug on Leishmania sp. is unknown at present.

Análise temporal da variabilidade da freqüência cardíaca no estado basal em idosos chagásicos na forma indeterminada em área endêmica

Com o objetivo de avaliar a função autonômica cardíaca em pacientes chagásicos residentes em área endêmica, foram avaliados, por meio da análise computadorizada da variabilidade da freqüência cardíaca, 28 pacientes idosos chagásicos na forma indeterminada, 28 pacientes idosos não-chagásicos e 28 adultos jovens. Todos os pacientes chagásicos realizaram eletrocardiograma, radiografia de tórax, estudo radiológico contrastado do esôfago e cólons e ecodopplercardiograma, sendo que os não-chagásicos deixaram de realizar apenas os exames contrastados. Não houve diferença estatisticamente significativa entre os grupos, quanto às dimensões sistólica e diastólica e função sistólica do ventrículo esquerdo. Não houve diferença estatisticamente significante entre os grupos, quanto à duração média do intervalo RR. Quanto à variância, desvio padrão, coeficiente de variação, e ao pNN50, houve diferença estatisticamente significante entre o grupo jovem e os idosos, mas não entre os grupos idosos. Concluímos que, no estado basal, os grupos idosos chagásicos e não-chagásicos não diferiram quanto à modulação autonômica cardíaca no domínio do tempo.

[Temporal analysis of cardiac frequency variability in basal condition in elderly chagasic subjects in indeterminate form in endemic área]

With the aim of evaluating the cardiac autonomic function in elderly chagasic patients living in an endemic area, we evaluated, by using computadorized heart rate variability, 28 elderly chagasic with the indeterminate form, 28 elderly non chagasic and 28 young healthy control. In all patients we performed conventional electrocardiogram, radiological investigation of thorax, and with contrast of esophagus and colons and echodopplercardiogram. Non chagasic patients did not perform only the exams with contrast. The systolic ventricular function was preserved in all subjects. There was no statistically significant difference between the groups with regard to mean duration of RR intervals. Considering the variance, standard deviation, variation coefficient and pNN50 there was statistically significant difference between the young and elderly groups but no difference was found when the analysis was performed in each one separately for these temporal indexes. We conclude that, in basal condition, the groups of elderly chagasic and no chagasic subjects did not differ as much as the cardiac autonomic modulation in time domain.

A comparison of three electrocardiogram coding systems for chronic Chagas' disease

OBJECTIVE

To compare three electrocardiogram coding systems (Buenos Aires, New York Heart Association, and modified Minnesota) for use with Chagas' disease.

METHODS

Between January 1976 and December 1978 persons older than 2 years of age living in the town of Agua Comprida, Minas Gerais, Brazil, underwent a patient history, physical examination, conventional electrocardiography, and serology for Chagas' disease. Those records were archived, and in 1999 from this sample, 100 seropositive individuals were matched by sex and age with 100 seronegative controls. The electrocardiograms of these 200 patients were read using the three coding systems. Each system was assessed in terms of its gradient, that is, the difference between the number of abnormalities found in the electrocardiograms of individuals with and without Chagas' disease.

RESULTS

The gradient was 7% for the New York Heart Association coding system, 15% for the modified Minnesota system, and 17% for the Buenos Aires one. The ability of the Buenos Aires method to detect electrocardiographic abnormalities was significantly greater in the group with Chagas' disease than in controls (P = 0.012), followed by the modified Minnesota system (P = 0.028) and the New York Heart Association system (P = 0.31). The Buenos Aires method was also easier to use, in terms of both the analysis of electrocardiograms and queries to a database.

CONCLUSIONS

Although the Buenos Aires method had advantages over the two other systems, some changes are still needed in it to make it more useful. It would be worth carrying out further studies to evaluate this method with the changes that we have suggested in this study.

[A serological survey of the infection by Echinococcus sp. in the municipality of Sena Madureira, AC]

A serological inquiry was performed in the municipality of Sena Madureira, Acre State, Brazil, to evaluate the individual contact with Echinococcus sp. The participants were recruited from two distinct populations: residents in the urban and rural areas, the latter distributed among riverside communities of the region. A total of 1,064 individuals were evaluated: 851 from the urban zone and 213 from the rural area. The study was divided into two phases: a serological screening, in which the blood samples were collected and then sent to the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (Serology Laboratory), Ribeirão Preto, SP, Brazil, for the serological test by counterimmunoelectrophoresis technique; and secondly an epidemiological inquiry for evaluating the individuals and their dwelling conditions and customs. Comparing the results of serological tests, the prevalence in the rural area was 6% against 3.5% in the urban area. The overall prevalence was 4%. The possibility of the existence of another intermediate host in the life cycle of Echinococcus vogeli was analyzed and the findings indicated the domestic pig as being the most probable.

[Extraintestinal finding of Isospora belli unizoic cysts in a patient with AIDS: case report]

This report describes the presence of Isospora belli unizoic cysts in mesenteric lymph nodes and of gametocytes in the gallbladder epitelium of a 26 year-old Brazilian male patient with Acquired Immune Deficiency Syndrome. This patient had received treatment for several times with sulfamethoxazole-trimethoprim. It is discussed the significance of I. belli tissue cysts as possible foci of resistance of the parasite and their association with the infection relapse even post-treatment with anticoccidian medication.

[Montenegro intradermoreaction after the test sequential repetitions in Porteirinha, Minas Gerais State, Brazil]

With the purpose of evaluating the response of sequential applications of Montenegro intradermoreaction (IDRM), we have repeated four times the test in the inhabitants of an endemic area for kala-azar, that resulted negative 3-4 years ago. Firstly, we have repeated three IDRM in those who remained negative, with a 60-day interval among them. In the second stage, we have performed a last reaction in all participants of the study. From the total of 49 individuals with prior negative IDRM, 19 (38.8%) have positivated the test in some of the times, 17 (34.7%) have given up the study and 13 (26.5%) remained with a negative result in all the applications. In the second stage, the repetition of IDRM has shown that from the 14 positive in some of the tests, 8 remained like this and 6 have become negative. Our results confirm the possibility of late hypersensitivity induction in some individuals as a consequence of IDRM application.

[Schistosomiasis in hyperendemic area of Taquarendi: I- Schistosoma mansoni infection and severe clinical forms]

The study was carried out in Taquarendi (Bahia), a caatinga zone with a small irrigated strip of land, where Biomphalaria glabrata snails are found. From the 1,532 inhabitants, 1,105 (72.1%) were submitted to clinical examination and 1058 out of them (95.7%) made stool examinations. Prevalence of schistosomiasis was 73.1% and 16.2% of these patients eliminated more than 1,000 eggs per gram of stool. By clinical examination, the size and the consistency of the left liver lobe were increased in 54% of the individuals and the spleen was palpable in 21.8%. The diagnosis of hepatosplenomegaly and of the advanced hepatointestinal clinical form was made, respectively, in 9.8% and 3.7%. A direct relationship between such clinical forms of the disease and the worm load over 1.000 S. mansoni eggs/g of fezes was found.

[Polycystic hydatid disease: report of two cases from the city of Sena Madureira, Acre, in Brazilian Amazon]

Two cases of Polycystic hydatid disease (PH) are reported from the same municipal district of the Brazilian Amazon region (Sena Madureira, Acre). Both had a similar clinical presentation and course over two years of follow-up. Initially the patients complained of pain in the right hypochondrium or upper abdomen and presented obstructive jaundice, fever, increased abdominal volume and weight loss. By image analysis, in addition to splenomegaly, multiple and coalescent cysts were detected in the liver. Serum samples were reactive by counterimmunoelectrophoresis. Treatment with albendazole resulted in partial improvement, with symptomatic relief and reduction in size of the lesions. This report stresses the importance of performing clinical-epidemiological studies of polycystic hydatid disease in the Brazilian Amazon and especially in the municipality of Sena Madureira where many other cases of PH may remain undiagnosed.

Efficacy of azithromycin in the treatment of cutaneous leishmaniasis

The present open pilot study was conducted to assess the efficacy of azithromycin for the treatment of patients with cutaneous leishmaniasis in Ara ua and Varzelândia, MG. Twenty-four patients with less of six months of disease evolution were treated after clinical examination, Montenegro test and a biopsy. The treatment schemes consisted of oral doses of 500 mg per day for 3, 5 and 10 days and of 1000 mg for two days. A clinical control was performed monthly and treatment cycles were repeated when necessary until full reepithelialization of the lesions. On the occasion of the final evaluation, 20 patients had completed the study and 17 of them (85%) were cured. The time to obtain a cure was 60 days ifor 6 (30%) patients, 90 days for 7 (35%), and 120 for 4 (20%). The three patients with treatment failure received a pentavalent antimonial for 20 days. No adverse reactions to the medication were observed and a 14 month follow-up did not show recurrence in any patient. These results suggest that azithromycin can be a good therapeutic option for the treatment of cutaneous leishmaniasis caused by Leishmania Viannia brasiliensis.

[Chagas' disease in the Amazon: an overview of the current situation and perspectives for prevention]

American Trypanosomiasis (Chagas' disease) due to Trypanosoma cruzi in the Amazon Region has become a target of scientific preoccupation in recent years because of the wide dispersion of infected vectors and intensive human migration into the region. An European Community and Latin America Triatominae Network international workshop held in July 2002 analyzed the general situation and the perspectives of human Chagas' disease in the area, concluding that although its occurrence remains sporadic, there is strong potential for the disease to spread, and a requirement for an integrated surveillance effort to be shared by all countries of the region.

Evaluation of the impact of chemical control measures and entomological surveillance on Chagas' disease in the counties of Mambaí and Buritinópolis, Goiás State, Brazil

Epidemiological surveillance activities were implemented in 1980 in Mambaí and Buritinópolis counties, Goiás State. Twenty years later the authors evaluated the impact of these vector control measures on Chagas' disease transmission, based on entomological indicators. Entomological investigation was conducted using the man-hour technique and covering all domiciles. In order to study vector food sources the stomach contents of triatomines were analyzed using the modified precipitins technique. Triatomines were shown to be present in 48 (71.6%) of the 67 locations. Peridomiciliary infestation rates in Mambaí and Buritinópolis were 8.7% and 12.1%, respectively, while intradomiciliary rates were 0.7% and 1.2%. Triatoma sordida was the species identified in 97.3% of all captured specimens. It was also the only species found to be naturally infected with Trypanosoma cruzi. Birds were the most frequent food source (45%) for Triatoma sordida. The most significant result was the complete absence of Triatoma infestans in the two counties.

Clinical and epidemiological aspects of Chagas disease

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. During the past decades, after urban migrations, Chagas disease became frequent in cities and a health problem in non-endemic countries, where it can be transmitted vertically and by blood transfusion or organ transplantation. Microepidemics of acute Chagas disease have been reported, probably due to oral transmission. Heart involvement is the major feature of the disease because of its characteristics, frequency, and consequences, and is also the source of most controversies. The indeterminate clinical form, despite its good prognosis on at least a medium-term basis (5-10 years), has acquired increasing importance due to the controversial meaning of the abnormality of some tests and the myocardial focal lesions found in many patients. Simultaneous evaluation of the parasympathetic and of the sympathetic system in the heart has been done by spectral analysis of heart rate. The physiopathological and clinical significance of denervation in Chagas disease is still incompletely understood. There are major divergences of opinion on specific treatment during the chronic phase because of the doubts about cure rates. Changes of Chagas disease prevalence in many countries have been certified by the Pan American Health Organization, and are ascribed to large-scale vector-control programmes with modern pyrethroid insecticides and to improvement in lifestyle.

[A 13-year clinical study on 190 chronic chagasic patients from Mambaí, Goiás, Brazil]

A prospective study was performed on the clinical, electrocardiographic (ECG) and radiologic aspects of the esophagus in 190 chagasic patients, for on average follow-up period of 13 years. We found 108 (56.8%) patients who remained in the same clinical state, 72 (37.9%) patients with progressive illness and 10 (5.3%) patients whose previous ECG abnormalities subsided. Thirty nine out of 72 patients with progressive disease developed cardiopathy or aggravation of previous illness, 32 developed into megaesophagus or an existing picture deteriorated and 12 developed or showed worsening of the colopathy. Of 72 patients, 11 presented with associated forms. The development of cardiopathy was greater in males 29.6% (21/71) than in females 15.1% (18/119), p =0.015. There were 19 new cases of cardiopathy, and 20 of aggravated previous disease. The incidence of megaesophagus was 14.9% (23/154), with nine patients whose previous disease worsened. The progression of colopathy was greater in females 9.2% (11/119) than in males 1.4% (1/71), p = 0.026.

Yellow fever

With the infestation by Aedes aegypti, urban yellow fever might already exist. This did not occur because of either the lacking of a sufficient contact between the diseased individual and the A. aegypti or perhaps because this, after sixty years without transmitting the virus, needs an adaptation phase to infecting again.

Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery

Three different periods may be considered in the evolution of knowledge about the clinical and epidemiological aspects of Chagas disease since its discovery: (a) early period concerning the studies carried out by Carlos Chagas in Lassance with the collaboration of other investigators of the Manguinhos School. At that time the disease was described and the parasite, transmitters and reservoirs were studied. The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disease; (b) second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American countries. Particularly important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of the Romaña sign in the 1930 decade, facilitating the diagnosis of the early phase of the disease. However, the chronic phase, which was the most important, continued to be difficult to recognize; (c) period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies conducted by Laranja, Dias and Nóbrega in Bambuí updated the description of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on, the disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d) period of enlargement of knowledges on the disease. The studies on denervation conducted in Ribeirão Preto by Fritz Köberle starting in the 1950 decade led to a better understanding of the relations between Chagas disease and megaesophagus and other visceral megas detected in endemic areas.

Absence of both circadian rhythm and Trypanosoma cruzi periodicity with xenodiagnosis in chronic chagasic individuals

Xenodiagnoses were performed every 3 hours using 10 Triatoma infestans 3rd instar for 24 to 72 hours, in 18 chronic chagasics with positive serology and/or xenodiagnosis. There was no statistically significant difference in the positivity of assays performed during the day (9:00 to 18:00 h) compared to those performed at night (21:00 to 6:00 h), (chi 2 = 0.1526 p = 0.696). Xenodiagnosis was performed in ten of the patients for 13 successive days but there was no periodicity detected in the positive assays.

[Clinical and laboratory renal alterations in patients with acquired immunodeficiency syndrome in relation to anatomopathological findings]

Clinical as well as renal anatomopathological data of 119 patients with acquired immunodeficiency syndrome from the Hospital of the Faculty of Medicine of Triângulo Mineiro, Uberaba, MG, Brazil, were studied. Mean age was 33 +/- 10.4 years (range 18 to 67 years). White (59%) and male (80%) individuals predominated. Ninety percent of patients came from Uberaba or neighborhood. There were 59 (50%) heterosexual, 25 (21%) homosexual, 17 (14%) bisexual and 18 (15%) unknown. Forty three percent were drug abusers. Fourteen (12.2%) of patients had serum creatinine higher than 3mg/dl, ten days before death, 64% of them showed acute tubular necrosis. Seventy one (61%) patients presented hyponatremia and 8 (7%) had hypernatremia. Hypokalemia was detected in 28 (24%) and hyperkalemia in 8 (7%) patients. Twenty four hours urinary protein was detected in 12 patients, 7 of them presenting more than 1g/24h. Two patients showed segmentar focal glomerulosclerosis, one of them with 24h urinary protein level of 5.5 g and serum creatinine 1.5 mg/dl and no edema. The most (56%) patients had tubulointerstitial nephritis. Clinical, laboratory and types of renal disorders in patients with acquired immunodeficiency syndrome are variable. The glomerular diseases were relatively scarce however, tubulointerstitial lesions are quite frequent, mainly interstitial nephritis and acute tubular necrosis. Not always an anatomoclinical correlation could be observed, because many times the electrolyte disorders were frequently observed only functionally.

[The behavior of Trypanosoma cruzi parasitemia in chronic chagasics over 13 years]

The parasitemia of 202 chronic chagasics was studied for approximately 13 years by repeated conventional xenodiagnoses. Mean patient age was 41.1 years. They lived in an endemic area; 124 were females and 78 were males. It was seen that the level of parasitemia oscillated. It went up in 14 individuals, went down in 42 and stayed at the same level in 146. In general the parasitemia was reduced. The percentage of xenopositive chagasics, which was 37.6%, 48.5%, and 51% in the first, second and third xenodiagnosis, respectively, in 1976/78, changed to 30.2% in 1988/91 (p = 0.00003). The percentage of positive pools, which was 15.2%, 20.9%, 20.8% in the first, second and third xenodiagnosis, respectively, in 1976/78, changed to 10.4% in 1988/91, (p = 0.00000001). There were 62 patients whose xenodiagnoses were all negative and 23 whose exams were all positive. The percentage of chagasics with high, medium and low parasitemia, which in 1976/78 was 9.4%, 20.8% and 69.8%, respectively, changed to 4.4%, 12.9% and 82.7%, respectively, in 1988/91.

Influence of Schistosoma mansoni infection on the reproductive capacity of albino mice

This paper reports reduction on the reproductive capacity of female mice infected with Schistosoma mansoni, either in the acute phase or in the chronic one of the disease. This decrease in the reproductive capacity was highly significant (93.3% and 86.7%, for the acute and chronic phases, respectively).

Human Schistosomiasis mansoni: IL-10 modulates the in vitro granuloma formation

Granuloma formation and modulation around Schistosoma mansoni eggs that are trapped in host tissues play a pivotal role during schistosomiasis. It has been demonstrated that the granuloma reactions differ in patients with the different clinical forms of the disease. The pathology during murine schistosomiasis has been correlated with a Th2 response while resistance to infection with a Th1 type response. In humans, very little is known about the role of different cytokines on the development of the disease. Here we demonstrate that IL-10 is an important cytokine regulating the in vitro granulomatous reactivity of PBMC from intestinal (INT) patients. This was evidenced by the fact that blockage of this cytokine in the in vitro granuloma assay lead to a significant increase in granuloma size with cells from INT patients but not with individuals in the acute phase or with the hepatosplenic (HS) form of schistosomiasis. These results demonstrate for the first time that, in context with the model, a Th2 cytokine in human schistosomiasis plays an important role in controlling morbidity.

[Renal anatomopathological changes in patients with acquired immunodeficiency deficiency syndrome]

Renal anatomopathological lesions were studied among 119 AIDS patients from Faculdade de Medicina do Triângulo Mineiro's University Hospital (Uberaba, MG, Brazil). From formalin-fixed blocks, slides were obtained and studied by light microscopy. Of 119 patients, 67 presented tubulointerstitial nephritis (TIN), 18 inespecific, 2 xantogranulomatous and infections agents were found in 48 as follows: mycosis in 28 (16 Cryptococcus sp; 9 Histoplasma sp, 1 Candida sp e 2 Paracoccidioides brasiliensis); bacteria in 18 (9 Mycobacterium sp), virus in 6 (Cytomegalovirus). Acute tubular necrosis was found in 43 cases (36.1%). Other diagnosis were: nefrocalcinosis (15.1%), arteriolar hyalinosis (22.7%), two cases of focal segmental glomerulosclerosis (1.7%) and one case of diffuse mesangial hyperplasia (0.8%). We conclude that the renal involvement in patients with AIDS, presents a wide spectrum of pathologies, secondary to complications related to opportunistic infections, therapeutic and diagnostic management, and the nephropathies associated to HIV.

Evaluation of SPf66 malaria vaccine efficacy in Brazil

This paper reports the efficacy results of the randomized, placebo-controlled, field trial of SPf66 malaria vaccine in Costa Marques, Rondonia, Brazil. This region is characterized by the seasonal distribution of Plasmodium falciparum and P. vivax infections, and the recent occupation by migrants from nonendemic areas. A total of 800 individuals of both sexes, ranging in age from seven to 60 years, were included in the study. Of the initial cohort, 572 participants completed the vaccination schedule. Clinical and parasitologic evaluations were obtained by active and passive searches on a periodic basis. The overall protective efficacy against P. falciparum infections was -1.6% (-32.9% to 22.4%), and 14.1% (-17.0% to 36.9%) for the first episode. The overall protective efficacy for P. vivax infections was -19.7% (-44.8% to 1.03%), and -10.8% (-41.1% to 12.8%) for the first episode. No statistical evidence of an overall significant protective effect of SPf66 malaria vaccine against P. falciparum and P. vivax malaria was obtained in this trial.

Cytokines as determinants of resistance and pathology in human Schistosoma mansoni infection

The role of different cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar results were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-gamma in the supernatants showed that PBMC from INT patients secreted low levels of IFN-gamma upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-gamma. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-gamma may be associated with resistance to infection.

Risk factors associated with taeniasis-cysticercosis in Lagamar, Minas Gerais State, Brazil

An epidemiological survey was carried out in 3,344 people of an urban town in Lagamar, Minas Gerais, Brazil--during 1992-1993, to evaluate the main risk factors related to taeniasis and cysticercosis. A total number of 875 (78.9%) houses were visited and 1080 (32.3%) subjects were clinically examined. Poor sanitary conditions were positively associated with former history of taeniasis or seizures in households (p < 0.05). It was remarkable the positive relationship between taeniasis and seizures when households were questioned and subjects were clinically evaluated (p < 0.05). The relative risk of seizures was 2.3 between households and 1.7 for individuals clinically examined respectively. The breeding of swine nearby and the chronic carriers of taeniasis are determinant factors in the maintenance of the epidemiological link between taeniasis and cysticercosis in endemic areas.

Cytokine regulation of human immune response to Schistosoma mansoni: analysis of the role of IL-4, IL-5 and IL-10 on peripheral blood mononuclear cell responses

The role of cytokines on the in vitro proliferative response of peripheral blood mononuclear cells (PBMC) from Schistosoma mansoni infected patients to soluble egg (SEA) and adult worm antigens (SWAP) were evaluated. The results obtained demonstrated that the proliferative response of PBMC from chronic intestinal (INT) patients to SEA and SWAP is increased by the blockage of IL-10 with specific monoclonal antibodies (MAb). The effects of these antibodies were readily reversed by the addition of recombinant IL-10. In contrast, no effect was observed on the PBMC response of acute and hepatosplenic patients (HS) in the presence of anti-IL-10. Anti-IL-4 antibodies decreased the PBMC response of the intestinal (INT) and HS individuals to SEA and SWAP, and the PBMC response of acute patients to SEA but not to SWAP. Addition of anti-IL-5 MAb did not decrease the PBMC response of acute patients to SEA or SWAP. These results suggested that IL-10 has an important role in the modulation of the immune response in chronic asymptomatic patients and that this cytokine may be an important factor in controlling morbidity.

Flow cytometric study of blood leucocytes in clinical forms of human schistosomiasis

The aim of this study was to examine three distinct groups of schistosomiasis patients and to determine whether cell phenotype profiles could be correlated with the different clinical forms of the disease. The data obtained indicate that Schistosoma mansoni infected patients have a lower percentage of CD3+ T cells than do non-infected individuals. Interestingly, infected patients presented more than twice the mean percentage of circulating activated T cells (CD3+HLA-DR+) when compared to the control group. Examination of T lymphocyte subpopulations showed that patients with the severe hepatosplenic form (HS) of the disease had lower levels of both CD8High+ and CD8Low+ cells when compared to the other groups of patients. All infected individuals had a higher percentage of circulating B cells, with an increase in the CD5+ B cell population that was more evident in the HS group. The data presented here are evidence to support a relationship between the hepatosplenic form of the disease, a decrease on the CD8+ cell population and an elevation on CD5+ B cells.

Genetic and environmental factors regulating blood pressure in childhood: prospective study from 0 to 3 years

OBJECTIVES

Blood pressure (BP) regulation depends on the interaction between multiple environmental and genetic factors. Of these, BP sensitivity to dietary sodium intake has been one that has been investigated in adults but not in children. The aim of the present study was to investigate, prospectively, the BP profile in relation to different genetic and hormonal factors, in the first 3 years of life.

POPULATION AND METHODS

Thirty-nine children born at term following normal pregnancies, with uncomplicated neonatal periods, were randomly selected to take part in the study. BP, weight and length were evaluated every 3 months from birth to 3 years. At the age of 12 months, haptoglobin phenotypes and plasma active renin concentration were determined as well as random urine evaluation of aldosterone, cAMP, dopamine and digoxin-like immunoreactive substances (DLIS). Family history of cardio-vascular diseases was also recorded.

RESULTS

Systolic BP (SBP) demonstrated a gradual increase until the age of 6 months with little variation up to 36 months. Tracking of SBP values was also observed from the first year as infants with high values (above the 75 percentile) maintained this tendency up to, at least, the age of 36 months. The comparison between SBP and diastolic BP (DBP) according haptoglobin phenotypes demonstrated that SBP was systematically higher in allele 1, with apparently an increasing tendency with age, although the differences did not have statistical significance. The comparative study between haptoglobin phenotypes, with correction for the covariates fractional excretion of sodium and potassium, showed that allele 1 carriers had significantly lower plasma renin and urine aldosterone and cAMP concentrations than allele 2, but dopamine excretion was found to be higher in allele 1 than in allele 2. There were no differences among variables relating to family history of cardiovascular disease.

CONCLUSIONS

There was an early tracking process of BP values from the first 6 months of life which persists through, at least, to the age of 36 months. Differences in sodium handling between haptoglobin 1 and 2 phenotypes were already present in early childhood, although no significant repercussion in BP values could be demonstrated in the 3-year duration of this study.

Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis

Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.

[The pupil in the chronic phase of Chagas disease and the reaction to pilocarpine and phenylephrine]

To develop a method to analyse pupillary disturbances in patients with chronic Chagas disease in an endemic area, ten chagasic and ten normal subjects were matched according to sex, age and race. Pupillary diameter and area were determined using projection and topography techniques and compared between groups. Both pupils were visualised simultaneously. In each case three photographs were taken under standardised illumination. The first photo was obtained without medication, the second, 30 minutes after instillation of 0,1% pilocarpine and the last 30 minutes after instillation of 3% phenylephrine (60 minutes after pilocarpine). Pupils of chagasic patients had a statistically significant greater initial diameter and area, irregularity of the pupil border, greater percentual reduction in diameter and area after pilocarpine 0.1% and greater percentual increase in diameter and area after 3% phenylephrine eyedrops. The method developed for this study was considered satisfactory. The results suggest ocular autonomic nervous system disturbances in chagasic patients.

Antibody response to Salmonella typhi in human schistosomiasis mansoni

Antibody response to Salmonella typhi O and H antigens was evaluated in 24 individuals with either hepatointestinal or hepatosplenic schistosomiasis mansoni before and after typhoid vaccination, and compared with that of non-infected controls. Before vaccination, Schistosoma-infected patients showed a higher frequency of positive antibody to O antigen and the same frequency to H antigen when compared with that of healthy individuals. However, those with hepatosplenic schistosomiasis showed higher titres of antibody to H antigen than those with hepatointestinal disease or healthy individuals. Infected subjects, particularly those with hepatointestinal disease, showed a decreased response after typhoid vaccine. This diminished ability to mount an immune response towards typhoid antigens during schistosomiasis may interfere with the clearance of the bacteria from blood stream and, therefore, play a role in the prolonged survival of salmonella as observed in some patients with chronic salmonellosis associated with schistosomiasis.

Safety evaluation of SPf66 malaria vaccine in Brazil

The frequency and description of side effects secondary to the subcutaneous application of SPf66 malaria vaccine and placebo are reported for each dose of application in the participants of the vaccine efficacy trial in Brazil. Side effects evaluated two hours after each application were detected in 8.0%, 30.2% and 8.8%, for the 1st, 2nd and 3rd dose, respectively, in the SPf66 group, and in 7.0%, 8.5% and 2.9% in the placebo group. Local reactions such as mild inflammation, nodule and pain or erythema frequently accompanied by pruritus were the most common reactions detected in both groups (3.8%, 29.1% and 8.5% in the SPf66 group and 4.0%, 7.6% and 2.5% in the placebo group). Among vaccinees, local side effects after the 2nd dose were more frequent in females. Systemic side effects were expressed mainly through general symptoms referred by the participants and were most frequent after the 1st dose in both groups (4.3% in the SPf66 group and 3.0% in the placebo group). Muscle aches and fever were referred by few participants. No severe adverse reactions were detected for either dose of application or group.

SPf66 vaccine trial in Brazil: conceptual framework study design and analytical approach

This paper describes the study population and the study design of the phase III field trail of the SPf66 vaccine in Brazil. Assessment of validity and precision principles necessary for the appropriate evaluation of the protective effect of the vaccine are discussed, as well as the results of the preliminary analyses of the gathered data. The analytical approach for the estimation of the protective effect of the vaccine is presented. This paper provides the conceptual framework for future publications.

[The epidemiological aspects of taeniasis-cysticercosis in an endemic area of Lagamar, Minas Gerais]

An epidemiological inquiry of humancysticercosis due to Taenia solium was carried out in Lagamar, Minas Gerais State, Brazil, in 1992. A survey of 1109 houses with 3344 inhabitants was made. The inquiry included 875 (86%) families and the questionnaire was answered by an informer, who was the father in 80% of the cases. One hundred pigsties, sheltering 406 swines in extremely precarious conditions, were found in 100 (11.4%) houses. A history on taeniasis in some member of the family was verified in 300 (34.2%) houses. A history of seizures was referred to by 125 (14.2%) of families. The outset of convulsion in adult age was characterized in 39 (37.8%) families. A history of mental disorder was reported in 53 (6.0%) of houses. Stool examinations were positive for Taenia spp in 24 (1.3%) of samples examined.

[Anisocoria in the chronic phase of Chagas' disease]

To compare the frequency of anisocoria in patients with chronic Chagas' disease a prospective double-blind study was done in 131 patients with positive serology for Chagas' disease and 138 negative, at Mambaí (GO-Brazil), which is an endemic area for Chagas' disease. To detect anisocoria, pupillometry was done with a millimetric ruler. Anisocoria was seen in 10(7.6%) patients with Chagas' disease and in 3(2.1%) normal subjects. The chi-square test showed statistical significance at level of 5%. Chagas' disease must be included among the causes of anisocoria.