Human cryptosporidiosis: detection of specific antibodies in the serum by an indirect immunofluorescence

Cryptosporidium sp., a coccidian parasite usually found in the faeces of cattle, has been recently implicated as an agent of human intestinal disease, mainly in immunocompromised patients. In the study realized, by an indirect immunofluorescence technique, specific immunoglobulins (IgG and IgM) have been demonstrated in human serum against Cryptosporidium oocysts. Purified oocysts were used as antigens in the indirect immunofluorecence assay. After analyzing this test in sera from selected groups of patients, the frequency of both specific IgG and IgM of immunocompetent children who were excreting oocysts in their faeces was 62% and in children with negative excretion of oocysts was 20% and 40%, respectively. In adults infected with the human immunodeficiency virus (HIV) and who were excreting Cryptosporidium in their stools, the frequency was 57% for IgG but only 2% for IgM. Twenty three percent of immunocompromised adults with not determined excretion of oocysts in their stools had anti-Cryptosporidium IgG in their sera. Children infected with human immunodeficiency virus had no IgM and only 14% had IgG detectable in their sera. The indirect immunoflorescence assay, when used with other parasitological techniques appears to be useful for retrospective population studies and for diagnosis of acute infection. The humoral immune response of HIV positive patients to this protozoan agent needs clarification.

A clinical, epidemological, laboratorial, histological and ultrasonographical evaluation of anti-HCV EIA-2 positive blood donors

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary "immunoblot" test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83.5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.

Assessment of chloroquine single dose treatment of malaria due to Plasmodium vivax in Brazilian Amazon

Malaria regions of the Amazon basin have been characterized by difficult access and non-compliance of the patients to treatment. In an attempt to assess the schizonticide efficacy of chloroquine in a single dose of 600 mg, the authors realized a double-blind, placebo-controlled trial in 132 outpatients with vivax malaria. Patients were distributed into two groups: group CPLA, given chloroquine 600 mg (single dose) on the first day of treatment, and two doses of placebo on second and third days. Group CHLO, given chloroquine 600 mg on first day and 450 mg on second and third day. Geometric means of the parasite density during the follow-up was similar in both groups. No differences were observed in the parasitological cure between the two groups (p = 0.442). There was clinical and parasitological efficacy in treatment of patients given a single-dose of chloroquine. This suggests that its restricted use could be indicated in remote areas of Brazilian Amazon Region, nevertheless the inadequate response of three patients indicates the need for further studies.

The "in vitro" antifungal activity evaluation of propolis G12 ethanol extract on Cryptococcus neoformans

Cryptococcosis is a worldwide disease caused by the etiological agent Cryptococcus neoformans. It affects mainly immunocompromised humans. It is relatively rare in animals only affecting those that have received prolonged antibiotic therapy. The propolis is a resin that can present several biological properties, including antibacterial, antifungal and antiviral activities. The standard strain C. neoformans ATTC 90112 was used to the antifungal evaluation. The tests were realized with propolis ethanol extract (PEE) G12 in concentrations from 0.1 to 1.6 mg mL-1. The evaluation of MIC and MFC were done according to DUARTE (2002)5. The inhibitory effect of PEE G12 on the fungal growing was seen at the concentration of 0.2 mg mL-1 and 1.6 mg mL-1 was considered a fungicidal one.

Excito-repellency effect of deltamethrin on triatomines under laboratory conditions

This work demonstrates that deltamethrin in low doses produces an excito-repellency effect on triatomines, as already observed for mosquitoes. A wooden box covered with a cloth impregnated with deltamethrin at doses of 2.5 and 5mg ai/m² was utilized for the experiment. The triatomine species studied were Triatoma infestans, Panstrongylus megistus, Rhodnius neglectus and Triatoma sordida. Adults were released in one of the sides of the box and their position was noted in subsequent periods. The observations were realized on the day the cloth was impregnated and subsequently repeated at 30 and 60 days for T. sordida; on day 120, the remaining species were included. Insect mortality and attempts at flight from the box were also observed. Excito-repellency was evident for all species and doses up to day 120. The only species that attempted to fly was P. megistus. The excito-repellency effect may be considered as an additional advantage to the insecticide power, as it should be able to prevent the installation of new colonies by females that fly into the homes, and at the moment of the spraying, it should promote the flushing out of triatomines from the wall crevices and from other shelters.

Molecular epidemiology of HIV-1 in Rio Grande, RS, Brazil

We conducted a molecular epidemiological study to investigate HIV-1 strains in Rio Grande, southern Brazil, searching for an association with transmission mode and risk behavior. Patients (185) identified at an AIDS treatment reference Hospital, from 1994 to 1997, were included; from which 107 blood samples were obtained. Nested PCR was realized once for each sample; for amplified samples (69) HIV subtypes were classified using the heteroduplex mobility assay. Subtypes identified were B (75%), C (22%) and F (3%). All infections with C were diagnosed after 1994. Comparing patients with B and C, no differences were detected regarding demographic, clinical and laboratory characteristics; survival analysis did not reveal differences in HIV to AIDS evolution. A higher proportion of injecting drug users, IDU (not significant, p<.07) was found among those with C. This suggests that C may have been introduced in this area through IDU, and is being spread, probably by their sexual partners, to persons with other risk practices.

Susceptibility of Triatoma sordida Stal, 1859 (Hemiptera: Reduviidae) to alpha-cypermethrin under natural climatic conditions

Abstract:INTRODUCTION:Despite the recommendations by interpretation of resistance ratios obtained in laboratory bioassays, little is known about the actual impact of these results in the effectiveness of vector control activities in the field. In this context, our objective was to determine the mean value of different resistance ratios obtained by laboratory bioassays performed as part of the chemical control strategies of Triatoma sordida in the field.METHODS:Field bioassays were developed in Monte Azul and Coração de Jesus (Southeast, Brazil). In each location, samples were formed with three domestic units treated with alpha-cypermethrin 20.0% (Alfatek (r) 200 SC). One day after spraying, 10 fifth-instar nymphs remained in contact with the surfaces treated (adobe with plaster, adobe without plaster, or wood) with insecticide in plastic cones for 72h. Three cones were exposed inside the intradomicile and the peridomicile. The insects in the control group were exposed to an insecticide-free piece of cardboard. Mortality was measured 72h after removal of the insects from the treated surfaces. The tests were realized in triplicate.RESULTS:Mortality was 100.0% in all locations, except for Monte Azul; Landinho (96.6%) and Coração de Jesus; Barriguda (96.6%).CONCLUSIONS:Although the resistant populations in laboratory tests proved to be susceptible in the field, this observation is not sufficient to suggest that the cut-off points used to justify the resistance ratio should be changed. In this sense, we recommend that laboratory and field bioassays are carried out with a greater number of Triatominae populations to allow more in-depth consideration of the subject.

Notes on the ethnoicthyology of fishermen from the Tocantins river (Brazil)

Ethnobiology includes the study of how populations perceive and classify organisms. This study focuses on the utilization and classification of fishes by fishermen from the Tocantins river. The study area is located between the cities of Imperatriz and Estreito (Maranhão and Tocantins States). Interviews with fishermen and collection of fish species were performed from October 1987 to June 1988. The criteria used by fishermen to classify fish species are mainly morphological, such as related to body shape and coloration. Fish habitat is also an information used in folk classification. Terrestrial plants and animals are a reference for some fish names. Fishermen showed a deeper knowledge and detailed classification of species of fish used for food, sale, or medicine. Folk classification represents the knowledge a population has on its environment, and it is more detailed on species which are part of its realized niche as indicated by this study.

Fisheries and fishing effort at the Indigenous Reserves Ashaninka/Kaxinawá, river Breu, Brazil/Peru

This article aimed to describe the subsistence fisheries of traditional populations of three ethnic groups, one Ashaninka and two Kaxinawá, lying on the banks of the River Breu. Initially, monitors were trained to fill logbooks with data from fisheries of the villages during an annual cycle (august/1995 august/1996). Based on these data, it was realized an inventory of the most common fish species caught as well as one about the fishing environment. The following results were obtained: i) Indians prefer to use pools, locally known as "poços", for fishing; ii) the most common caught species are the "mandis" (35%, Pimelodidae), armored catfishes (Loricariidae), specially Hypostomus sp. (25%), the "curimatá" (9%, Prochilodus sp.) and the "saburus" (8%, Curimatidae), among others; iii) the fishing gears that lead to a high rate of fishing are the native "tingui", nets and bow and arrows; iv) fisheries are more intensive during summer; v) the fishing effort and their associated factors statistically significant in predicting the catches in the Indian Reserve were f1 = number of fishermen, f2 = (number of fishermen*total time devoted to fishing), f3 = [(number of fishermen)*(total time devoted to fishing)-(the time displacement)] and the factor villages and fishing gears; vi) although almost all the fisheries are done by walking to the fishing places, catches increase when paddle boats are used; and vii) the most active fishermen belong to Kaxinawá tribe.

Genetic breeding on the bee Melipona scutellaris (Apidae, Meliponinae)

A selection of queens of Melipona scutellaris through the most productive colonies were carried out during eight months in an orange honeyflow. Each of the colonies was evaluated by its production, that is, the gross weight production ( pollen, brood, geopropolis and wax of each hive). With this data a coefficient of repeatability was estimated by the intraclass correlation method, obtained r = 0.835 ± 0.071. The repeatibility is very high showing that the analysed data (production) is repeatable. Selection was then carried out using the regression coefficient of each colony and the respective production gain. Using these data the colonies were divided into three groups according to the method Vencovsky and Kerr (1982): a with the colonies of highest productivity, b of least productivity, and c of intermediary productivity. Colonies with the highest production (Group a) gave their queens to those of the lowest production (Group b) after their queens were taken out and killed; while those of intermediate (Group c) stayed with the same queens during the entire experiment both before and after the selection. The modifications in weight, that is, the genetic response was (R)= 7.98 gr per day which indicated a selection gain. The estimate of the realized herdability is twice the rate of the response to selection (R) by the selection differential (S2). That is then h²R=2(R/S2) then h²R= 0.166

Comportamento dos cromossômios na meiose de Euryophthalmus rufipennis Laporte (Hemiptera Pyrrhocoridae)

In this paper an account is given of the principal facts observer in the meiosis of Euryophthalmus rufipennis Laporte which afford some evidence in favour of the view held by the present writer in earlier publications regarding the existence of two terminal kinetochores in Hem ip ter an chromosomes as well as the transverse division of the chromosomes. Spermatogonial mitosis - From the beginning of prophase until metaphase nothing worthy of special reference was observed. At anaphase, on the contrary, the behavior of the chromosomes deserves our best attention. Indeed, the chromoso- mes, as soon as they begin to move, they show both ends pronouncedly turned toward the poles to which they are connected by chromosomal fibres. So a premature and remarkable bending of the chromosomes not yet found in any other species of Hemiptera and even of Homoptera points strongly to terminally localized kinetochores. The explanation proposed by HUGHES-SCHRADER and RIS for Nautococcus and by RIS for Tamalia, whose chromosomes first become bent late in anaphase do not apply to chromosomes which initiate anaphase movement already turned toward the corresponding pole. In the other hand, the variety of positions assumed by the anaphase chromosomes of Euryophthalmus with regard to one another speaks conclusively against the idea of diffuse spindle attachments. First meiotic division - Corresponding to the beginning of the story of the primary spermatocytes cells are found with the nucleus entirelly filled with leptonema threads. Nuclei with thin and thick threads have been considered as being in the zygotente phase. At the pachytene stage the bivalents are formed by two parallel strands clearly separated by a narrow space. The preceding phases differ in nothing from the corresponding orthodox ones, pairing being undoubtedly of the parasynaptic type. Formation of tetrads - When the nuclei coming from the diffuse stage can be again understood the chromosomes reappear as thick threads formed by two filaments intimately united except for a short median segment. Becoming progressively shorter and thicker the bivalents sometimes unite their extremities forming ring-shaped figures. Generally, however, this does not happen and the bivalents give origin to more or less condensed characteristic Hemipteran tetrads, bent at the weak median region. The lateral duplicity of the tetrads is evident. At metaphase the tetrads are still bent and are connected with both poles by their ends. The ring-shaped diakinesis tetrads open themselves out before metaphase, showing in this way that were not chiasmata that held their ends together. Anaphase proceeds as expected. If we consider the median region of the tetrads as being terminalized chiasmata, then the chromosomes are provided with a single terminal kinetochore. But this it not the case. A critical analysis of the story of the bivalents before and after the diffuse stage points to the conclusion that they are continuous throughout their whole length. Thence the chromosomes are considered as having a kinetochore at each end. Orientation - There are some evidences that Hemipteran chromosomes are connected by chiasmata. If this is true, the orientation of the tetrads may be understood in the following manner: Chiasmata being hindered to scape by the terminal kinetochores accumulate at the ends of the tetrads, where condensation begins. Repulsion at the centric ends being prevented by chiasmata the tetrads orient themselves as if they were provided with a single kinetochore at each extremity, taking a position parallelly to the spindle axis. Anaphase separation - Anaphase separation is consequently due to a transverse division of the chromosomes. Telophase and secund meiotic division - At telophase the kinetochore repeli one another following the moving apart of the centosomes, the chiasmata slip toward the acentric extremities and the chromosomes rotate in order to arrange themselves parallelly to the axis of the new spindle. Separation is therefore throughout the pairing plane. Origin of the dicentricity of the chromosomes - Dicentricity of the chromosomes is ascribed to the division of the kinetochore of the chromosomes reaching the poles followed by separation and distension of the chromatids which remain fused at the acentric ends giving thus origin to terminally dicentric iso-chromosomes. Thence, the transverse division of the chromosomes, that is, a division through a plane perpendicular to the plane of pairing, actually corresponds to a longitudinal division realized in the preceding generation. Inactive and active kinetochores - Chromosomes carrying inactive kinetochore is not capable of orientation and active anaphasic movements. The heterochromosome of Diactor bilineatus in the division of the secondary spermatocytes is justly in this case, standing without fibrilar connection with the poles anywhere in the cell, while the autosomes are moving regularly. The heterochromosome of Euryophthalmus, on the contrary, having its kinetochores perfectly active ,is correctly oriented in the plane of the equator together with the autosomes and shows terminal chromosomal connection with both poles. Being attracted with equal strength by two opposite poles it cannot decide to the one way or the other remaining motionless in the equator until some secondary causes (as for instances a slight functional difference between the kinetochores) intervene to break the state of equilibrium. When Yiothing interferes to aide the heterochromosome in choosing its way it distends itself between the autosomal plates forming a fusiform bridge which sometimes finishes by being broken. Ordinarily, however, the bulky part of the heterochromosome passes to one pole. Spindle fibers and kinetic activity of chromosomal fragments - The kinetochore is considered as the unique part of the chromosome capable of being influenced by other kinetochore or by the poles. Under such influence the kinetochore would be stimulated or activited and would elaborate a sort of impulse which would run toward the ends. In this respect the chromosome may be compared to a neüròn, the cell being represented by the kinetochore and the axon by the body of the chromosome. Due to the action of the kinetochore the entire chromosome becomes also activated for performing its kinetic function. Nothing is known at present about the nature of this activation. We can however assume that some active chemical substance like those produced by the neuron and transferred to the effector passes from the kinetochore to the body of the chromosome runing down to the ends. And, like an axon which continues to transmit an impulse after the stimulating agent has suspended its action, so may the chromosome show some residual kinetic activity even after having lost its kinetochore. This is another explanation for the kinetic behavior of acentric chromosomal fragmehs. In the orthodox monocentric chromosomes the kinetic activity is greater at the kinetochore, that is, at the place of origin of the active substance than at any other place. In chromosomes provided with a kinetochore at each end the entire body may become active enough to produce chromosomal fibers. This is probably due to a more or less uniform distribution and concentration of the active substance coming simultaneously from both extremities of the chromosome.

Action of growth regulators on production of soybean cultivar Davis

This research deals with the effects of exogenous growth regulators on production of soybean plant (Glycine max cv.. Davis) under greenhouse conditions, At the flower anthesis, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm was applied. Other two applications with TiBA, with intervals of four days, were realized. Before flowering, Agrostemin (1 g/10 ml/3 1), gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm were applied. It was observed that CCC and TIBA reduced stem dry weight. Soybean plants treated with TIBA reduced weight of pods without seeds , seed number and seed weight.

Action of growth regulators on soybean cultivar Davis

The effects of growth regularots on soybean plant (Glycine max) under greenhouse conditions were studied. Before flower ing, Agrostemmin (1 g/10 ml/3 1), gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm were applied. At the flower anthesis, 2,3,5 - triio dobenzoic acid (TIBA) 20 ppm was applied. Other two applications with TIBA, with intervals of four days, were realized. Treatment with GA increased plant height while CCC presented a tendency to reduce it. Numbers of leaves, internods, and stems were not affected by the growth regulators.

Effects of growth regulators on productivity of soybean (Glycine max cv. Davis) under competition

The effects of growth substances on productivity of 'Davis' soybean maintained under competition was investigated. Before the flowering, Agrostemmin (1 g/10 ml/3 1), gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm were applied. At the flower anthesis, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm was applied. Other two applications with TIBA, with intervals of four days, were realized. The growth regulators did not affect the productivity of 'Davis' soybean maintened under competition. The competition among plants did not affect the stem dry weight and number of pods, and seeds. The competition reduced weight of pods without seeds, seed weight, and weight of 100 seeds.

Os anofelinos do sub-gênero kerteszia em relação à distribuição das bromeliáceas em comunidades florestais do município de Brusque, Estado de Santa Catarina

The present work is part of the studies realized under the authority of the National Service of Malaria (Brazil), with the collaboration of scientists of the Oswaldo Cruz Institute, in some forests of the southern part of Brazil.This is the first of a series and its subject is the development of the Anopheles mosquitoes of the kerteszia in water collected in Bromeliaceae leaves. The ecology of Bromeliaceae was studied in a previous work. The botanical material was classified by specialists from several botanical institutions from Europe and the United States of America. The most important ecological relations of the “bromeliad-kerteszia” problem were presented through four indices: 1st Positivity index – Relative frequency of bromeliad with watery forms in the bromeliad examined. 2nd Larval index – Mean number of watery forms in the positive bromeliad. 3rd Ovoposition index – Product of the Positivy index by the Larval index. 4th MK index – Product of the Ovoposition index by the total number of bromeliad, positive or not, in a unity of area (1.000 m²). The capture of flying forms in relation to the relative humidity was also studied. From the several forests of the Brusque region we have selected one community of each type, which were the most representative forests in Southern Brazil. Conclusions on the “bromeliad-kerteszia” problem – From a general point of view only a few factors are really important and these are listed below: 1°) The volum of water on the bromeliad. 2°) The level where the bromeliad is fixed. 3°) The number of bromeliad in unity of area. The distribution of microclimas in the forest through the considered levels has a direct influence on the species of subgenus Kerteszia (qualitative influence) and an indirect influence through the ecological distribution of the more frequent bromeliad with best qualities as biotope for the watery forms (qualitative influence). The MK index is roughly proportional to the square of half the total number of Bromeliaceae in a certain type of forest. Then the MK index would be a certain function of the ecological type of the forest and of the total number of bromeliad in a unity of area. MK approximately α x (x/10)² . x = n° of bromeliad in a unity of área (1.000 m²); α = qualitative factor. It would be interesting to see if this proportion is maintained when we have examined a greater number of forests of different types.