First molecular-based detection study of Leishmania infantum in the Tapirapé indigenous population in the Brazilian Amazon.

Species of the genus Leishmania parasitize mammals and have life cycles that alternate between vertebrate and invertebrate hosts. Most species develop in a hematophagous arthropod and infect a specific vertebrate host that may belong to diverse orders and families. Visceral leishmaniasis is a chronic zoonosis with a wide geographic distribution, affecting 350 million people globally, mostly in areas with a high risk of infection. In Brazil, this disease not only has a high incidence but is also expanding to new areas, both in urban centers and rural areas, including territories with tribal communities, due to increasing human intervention. The objective of this study was to perform cathepsin L-like gene-based molecular diagnosis of Leishmania infantum in the indigenous Tapirapé ethnic group in the state of Mato Grosso. From the 372 individuals assessed, only 0.8% (3/372) tested positive for L. infantum, all from the same village (Urubu Branco). Despite the small number of infected individuals, this study demonstrates the first human cases of Leishmania infantum infection in this population, suggesting the need for regular monitoring of visceral leishmaniasis in the area and leading to a broad discussion on the planning and implementation of public health measures for the indigenous population, while respecting their distinctive territories and culture.

An alternative method for DNA extraction and PCR identification of Entamoeba histolytica and E. dispar in fecal samples.

Since it is known that Entamoeba dispar is non-pathogenic and morphologically similar to E. histolytica, there are many targets used in PCR for differentiating these species. However, obtaining high quality DNA from fecal samples is fundamental for PCR. Most methods are laborious or use kits that make diagnosis expensive. In the present work, a new simple, fast and cheap technique of DNA extraction from fecal samples was combined with a PCR for an episomal target in order to identify E. histolytica and E. dispar in feces.

Allometric coefficients of major chemical components of meat quail raised in different thermal environments.

The objective of the present study was to estimate and compare allometric coefficients of the major chemical components of meat quail raised in different thermal environments, based on protein weight of feather free body (FFB) and feathers. In total, 300 meat quail, males and females, were distributed in a completely randomized design with 2 treatments (climatized environment, 26°C, and non-climatized environment, 29°C) and 6 replicates of 25 birds each. On the first day, 36 birds were selected to form the reference group and from this day on, 2 quail were weekly sampled from each cage. All selected birds were fasted for 24 h, weighed, slaughtered, plucked, and reweighed. The FFB and feathers were ground separately to obtain homogeneous samples, which were freeze-dried to determine the water content, and thereafter, ground again in a micromill before analyzing for protein, lipid, and ash using AOAC procedures. The adjustment of the allometric equations was made using crude protein (CP) weight as the independent variable and water, lipid, and ash weight as the dependent variables. The data of each dependent variable were transformed into natural logarithm (ln), regressed according to lnCP, and subjected to a parallelism test. In the FFB, water showed early development and lipid and ash showed late development in relation to the CP weight. In feathers, water and ash weight showed early development in relation to the feathers protein weight, whereas lipids showed late development. The environments of 26°C and 29°C did not affect the allometric coefficients that described the growth between the chemical components in the body and in the feathers, except for lipids in male FFB, that showed higher allometric coefficient at 29°C than 26°C. Describing the allometric relationships between the major chemical components of meat quail body is an important step in supporting future research comprised modeling of body growth and nutrition for meat quail.

Resuscitative procedures at birth in late preterm infants.

OBJECTIVE: Evaluate the need for resuscitative procedures at birth, in late prematures. STUDY DESIGN: This prospective cohort study enrolled all liveborn infants from 1 to 30 September 2003, with 34 to 41 weeks of gestation without congenital anomalies, born in 35 public hospitals of 20 Brazilian state capitals. Logistic regression analyzed variables associated with the need for bag and mask ventilation. RESULT: Of the 10 774 infants studied, 1054 were late preterms and 485 required resuscitative measures. Of the 1054, 338 (32%) received only free-flow oxygen, 143 (14%) were bag and mask ventilated, 27 (3%) were intubated and 10/27 received chest compressions and/or medications. Bag and mask ventilation in late preterms was associated with twin gestation, maternal hypertension, nonvertex presentation, cesarean delivery and lower gestational age. CONCLUSION: Improving control of maternal hypertension, prolonging gestation for 1 to 2 weeks and restricting operative deliveries could decrease the need of resuscitation of late preterms at birth.

First molecular-based detection study of Leishmania infantum in the Tapirapé indigenous population in the Brazilian Amazon

Species of the genus Leishmania parasitize mammals and have life cycles that alternate between vertebrate and invertebrate hosts. Most species develop in a hematophagous arthropod and infect a specific vertebrate host that may belong to diverse orders and families. Visceral leishmaniasis is a chronic zoonosis with a wide geographic distribution, affecting 350 million people globally, mostly in areas with a high risk of infection. In Brazil, this disease not only has a high incidence but is also expanding to new areas, both in urban centers and rural areas, including territories with tribal communities, due to increasing human intervention. The objective of this study was to perform cathepsin L-like gene-based molecular diagnosis of Leishmania infantum in the indigenous Tapirapé ethnic group in the state of Mato Grosso. From the 372 individuals assessed, only 0.8% (3/372) tested positive for L. infantum, all from the same village (Urubu Branco). Despite the small number of infected individuals, this study demonstrates the first human cases of Leishmania infantum infection in this population, suggesting the need for regular monitoring of visceral leishmaniasis in the area and leading to a broad discussion on the planning and implementation of public health measures for the indigenous population, while respecting their distinctive territories and culture.

Neutralizing potency of horse antibothropic antivenom. Correlation between in vivo and in vitro methods.

The correlation coefficients between in vivo neutralization of lethal toxicity (ED50), neutralization of the hemolytic activity (PLA2) and levels of antibodies measured by ELISA, was investigated to test the potency of horse anti-bothropic antivenom. Twenty six horses were hyperimmunized with Bothrops venoms (B. alternatus, B. jararaca, B. jararacussu, B. neuwiedii and B. moojeni). To set up an indirect ELISA, for neutralization of PLA2 activity and for determination of ED50 in Swiss mice, the whole Bothrops jararaca venom (reference venom for assessing the bothropic antivenom potency in Brazil) was used. The toxic fraction (purified from B. jararaca venom by Sephadex G-100 chromatography) was also used as antigen for ELISA. All antivenoms analyzed effectively neutralized the lethal activity in the range of 1.6 to 9.6 mg/ml of antivenom. The correlation coefficient between ED50 and ELISA antibody titers against the crude venom and toxic fraction was r = 0.65 (P < 0.001) and r = 0.85 (P < 0.0001), respectively. Correlation between ED50 and neutralization of PLA2 activity was r = 0.52 (P < 0.01), and the correlation between ELISA antibody titers and neutralization of PLA2 activity was r = 0.58 (P < 0.002). Thus, the ELISA which measures only the antibody against the major toxic fraction of the B. jararaca venom should be most suitable for use as an in vitro assay of bothropic antivenom potency.

Effective immune protection of pigs against cysticercosis.

A scolex protein antigen (SPA) was prepared from cysticerci of Taenia solium obtained from naturally infected pigs. Yorkshire pigs were vaccinated with SPA plus incomplete Freund's adjuvant (IFA) or with SPA plus Corynebacterium parvum (CP). Controls were given IFA plus phosphate-buffered saline (PBS) or CP plus PBS. All animals were given three subcutaneous injections at 20-day intervals. Ten days after the third injection, the pigs were fed with 10(4) viable eggs of T. solium. All pigs developed a delayed type hypersensitivity, and a transient eosinophilia after the first dose of vaccine. High titers of specific antibodies were detected in the sera of vaccinated animals and in infected controls. A protection level of 71.43% was recorded in animals vaccinated with SPA plus IFA and of 75.00% in those vaccinated with SPA plus CP.

Experimental infection of bovines with oocysts of Toxoplasma gondii.

Calves aged 3 months were readily infected with oocysts and cysts of Toxoplasma gondii administered by oral route. Fever, respiratory distress, nasal discharge and hyperemia of the conjunctivas were the most significant clinical signs noted in the infected animals. Parasitemia was demonstrated in all infected calves. It occurred on different days and up to 62 days after the infection. Toxoplasma was demonstrated in tissues of all infected calves, and the organ most frequently parasitized was the lymph node. Parasitism of the retina was demonstrated in two calves. All infected animals had antibody against T. gondii in their serum. The Sabin-Feldman dye test and the indirect immunofluorescent test were both useful in detecting antitoxoplasma antibody.

Epidemiological aspects of Babesia equi in horses in Minas Gerais, Brazil.

The prevalence of Babesia equi in two climatic regions of Minas Gerais state was determined using the indirect fluorescent antibody test (IFAT) with blood samples obtained from horses in two slaughterhouses. Of 399 samples, 241 (60.4%) showed a positive reaction. Anti-B. equi antibody was detected in every county studied, the prevalence being 59.7% for horses in the area where the temperature rises above 18 degrees C in winter and 61.4% in the area where it remains below 18 degrees C, indicating that climatic variation has no substantial effect on the prevalence of the infection in Brazil. Blood samples collected from all 95 horses on a ranch in the state of Minas Gerais, Brazil, on which clinical babesiosis had never been reported, were subjected to the IFAT Anti-B. equi antibodies were detected in horses of all ages, but with a significantly lower prevalence in animals less than 6 months old.

Purification and biochemical characterization of Eumiliin from Euphorbia milii var. hislopii latex.

A protease, which we designate Eumiliin, was isolated from the latex of Euphorbia milii var. hislopii by a combination of ion-exchange chromatographic steps using DEAE-Sephacel and gel-filtration with Sephadex G-75. Eumiliin is a monomeric protein with an apparent molecular mass of 30 kDa by SDS-PAGE under reducing conditions and gave one main peak at 29,814 KDa in MALDI-TOF/TOF mass spectrometry. Eumiliin has caseinolytic and fibrinogenolytic activities, but no hemorrhagic or defibrinating activities. The enzyme readily hydrolyzes the Aalpha-chain of fibrinogen and, more slowly, the Bbeta-chain. Its fibrinogenolytic activity is inhibited by beta-mercaptoethanol and leupeptin. In contrast, EDTA and benzamidine did not affect the activity of Eumiliin. The caseinolytic activity of Eumiliin had a pH optimum of 8.0 and was stable in solution at up to 40 degrees C; activity was completely lost at >or=80 degrees C. Intraplantar injection of Eumiliin (1-25 microg/paw) caused a dose- and time-dependent hyperalgesia, which peaked 1-5h after enzyme injection. Intraplantar injection of Eumiliin (1-25 microg/paw) also caused an oedematogenic response that was maximal after 1h. Morphological analyses indicated that Eumiliin induced an intense myonecrosis, with visible leukocyte infiltrate and damaged muscle cells 24h after injection.

Effects of glycerol on the thermal dependence of the stability of human erythrocytes.

Incubation of human blood in saline solution of 0-36% (v/v) ethanol for 30 min produces lysis or stabilization of erythrocytes depending on the ethanol concentration. Under less elevated concentrations of ethanol, erythrocytes are present in expanded shapes (R state) that present lower stability and suffer lysis with increase in the ethanol concentration. Under more elevated concentrations of ethanol, erythrocytes are present in contracted shapes (T state) that have higher stability and suffer lysis at even more elevated ethanol concentrations. This work evaluated the effects of glycerol (0 to 2.0 M) and temperature (7 to 47 degrees C) on the stability of the R erythrocytes, characterized by the ethanol concentration at the mid-transition point (D (50R )) of the hemolysis curve (D (50R )). D (50R ) declined sigmoidally with increase in the glycerol concentration or temperature, due to transition of the R to the T state erythrocytes. In 1.5 M glycerol, the erythrocytes stability decreased below 32 but increased above 37 degrees C. The combination of temperature, glycerol and ethanol actions generates a critical value of osmotic pressure below which the R state predominates and above which the T state predominates. At 7 degrees C 1.5 M glycerol decreased the erythrocytes stability against ethanol but increased the erythrocytes stability against hypotonic shock. Those conditions favor the R state, which has a lower stability against ethanol; however, in the absence of ethanol, glycerol determines less water entrance in the erythrocytes, making more difficult its lysis by hypotonicity.

Prevalência de anticorpos anti-Rickettsia spp. em cães da cidade de Belo Horizonte, MG / Prevalence of antibodies anti-Rickettsia in dogs from Belo Horizonte, MG, Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Rickettsia spp. in dogs from Belo Horizonte, MG. For this purpose, serum samples from 453 dogs were collected during the rabies vaccination campaign and tested by the indirect immunofluorescence assay (IFA) using five antigens: Rickettsia bellii, Rickettsia amblyommii, Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia felis. The endpoint titer reacting with each antigen was determined and serum was considered positive if it reacted at the 1:64 dilution. Serum showing titer for a Rickettsia species at least four-fold higher than that observed for any other Rickettsia species was considered homologous to the first Rickettsia species. Only three (0.66%) dogs reacted positively to at least one Rickettsia species and one serum showed to be homologous to R. rickettsii. These results showed a low prevalence of antibodies anti-Rickettsia spp. in dogs from Belo Horizonte city. However, other serosurvey needs to be performed for surveillance of the endemic status of the disease in the municipal district.

Susceptibility of Brazilian samples of Boophilus microplus to organophosphorus acaricides.

This paper describes the susceptibility of various samples of Boophilus microplus from the southern region of Minas Gerais State in Brazil to the 4 commonest organophosphorus acaricides employed in the area. All samples showed some degree of resistance to each of the compounds used. The resistance factor varied from 1.42 to 132.90, being less in the case of dicrotophos fenthion than with chlorpyrifos and coumaphos.

[Natural development of gastrointestinal helminthiasis in calves born during the dry season in Guaira, State of São Paulo, Brazil]. / Curso natural das helmintoses gastrintestinais em bezerros nascidos durante a "estação seca" em Guaíra, Estado de São Paulo, Brasil.

Proceeding with their observations on bovine nematode epidemiology in Guaíra, State of São Paulo, the authors carried a study on the natural development of nematode infections in crossbred calves born at the dry season. The fecal nematode egg counts per gram (e.p.g.) performed every fortnight were positive at the start, in October, when calves were two months old, and reached the peak when they were five months old; cultures of faeces revealed larvae of Cooperia, Haemoncus, Oesophagostomum and Trichostrongylus. From this time on, until 12.5 months old, when the calves were slaughtered, the variable e.p.g. decreased continually, the average being, in the last examinations, 40 e.p.g. Strongyloides eggs were present in the faeces when the calves were two months old but they disappeared by the 5th month of age. The post-mortem examination revealed the following species of nematodes: Haemoncus similis, Haemoncus contortus, Trichostrongylus axei, Bunostomum phlebotomum, Cooperia punctata, Cooperia pectinata, Oesophagostomum radiatum, Trichuris discolor and Dictyocaulus viviparus.

Activity of 9-acridanone-hydrazone drugs detected at the pre-postural phase, in the experimental schistosomiasis mansoni.

The compound Ro-15.5458/000, derivative in the class of 9-acridanone-hydrazones, was found to be effective against Schistosoma mansoni in mice, killing almost all the skin schistosomules (24 hr after infection), when administered at the dose of 100 mg/kg. In experiments carried out with Cebus monkeys, the drug was shown to be fully effective at 25 mg/kg, 7 days after infection. These data, associated with the good results obtained earlier at the post-postural phase of schistosomiasis, allow the inference that this promising compound may be important in the set of antischistosomal drugs, depending on further toxicological and clinical tests.

Control of schistosomiasis mansoni in Ravena (Sabará, state of Minas Gerais, Brazil) through water supply and quadrennial treatments.

In this study, the results obtained in a control programme of schistosomiasis in Ravena (Sabará, Minas Gerais) between 1980 and 1992 are evaluated. Control measures used in this programme were: specific treatment of the people infected with Schistosoma mansoni at four year-intervals (1980/84/88) and the supply of tap water to 90% of the residences in 1980. A significant reduction of the prevalence (36.7% to 11.5%, p < or = 0.05) and of the intensity of the infection (228.9 eggs per gram of feces (epg), s = 3.7 to 60.3 epg, s = 3.5, p < or = 0.05) was observed. No cases of the severe form of the disease were diagnosed in the area. Factors independently associated with the infection were in 1980 daily sand extraction and the lack of tap water in residences and in 1992 daily sand extraction and fishing and weekly swimming. Concluding, the supply of tap water together with quadrennial treatments significantly diminished both the prevalence and intensity of the S. mansoni infection, with the additional gain of persistent low indices even after four-year intervals between the treatments.

Purification and functional characterization of two fibrinogenolytic enzymes from Bothrops alternatus venom

Two fibrinogenolytic enzymes, Bothrops alternatus metalloprotease isoform (BaltMP)-I and II, were purified from Bothrops alternatus venom using Diethylaminoethyl (DEAE) Sephacel, Sephadex G-75 and Heparin-Agarose column chromatography. Purified BaltMP-I and II ran as single protein bands on analytical polyacrylamide gel electrophoresis and showed molecular weights of 29000 and 36000, respectively, under reducing conditions in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). BaltMP-II, but not BaltMP-I, displayed blood-clotting activity in bovine plasma, which was about 10-fold higher than that of the crude venom. Both enzymes were proteolytically active against bovine fibrinogen as substrate. When fibrinogen and each enzyme were incubated at 37°C, at a ratio of 1:100 (w/w), BaltMP-II cleaved preferentially the Aalpha -chain and more slowly the Bbeta -chain. The action of BaltMP-I was similar, but lower. None of the proteases degraded the gamma-chain of fibrinogen. The fibrinogenolytic activity of the enzymes was inhibited by 1,10-phenanthroline, suggesting they are metalloproteases. Since both enzymes were found to cause defibrinogenation when intraperitoneally (i.p.) administered to mice, they can be of medical interest as a therapeutic agent in the treatment and prevention of arterial thrombosis.(AU)

Atividade antimicrobiana de bactérias lácticas de embutidos curados frente a Listeria monocytogenes / Antimicrobial activity of lactic acid bacteria isolated from Brazilian dry fermented sausages against Listeria monocytogenes

Cepas de bactérias lácticas recuperadas de 336 colônias isoladas e selecionadas foram submetidas ao teste de atividade antimicrobiana direta, que identificou as produtoras de substâncias antimicrobianas capazes de inibir in vitro o desenvolvimento de duas cepas indicadoras de Listeria monocytogenes. As 108 cepas que inibiram diretamente pelo menos uma das cepas indicadores receberam a denominaçäo DTEI e foram selecionadas para o teste de atividade antimicrobiana indireta contra as mesmas cepas de L. monocytogenes, assim como frente a outras cepas de bactérias lácticas de origens diversas. Essa atividade inibidora indireta foi avaliada por meio de sobrenadantes isentos de células, esterilizados por meio de microfiltraçäo, eliminando-se os principais compostos responsáveis por ela, como por exemplo os ácidos orgânicos e o peróxido de hidrogênio, mediante o ajuste do pH e a liofilizaçäo dos sobrenadantes. Oito cepas de bactérias lácticas apresentaram atividade antimicrobiana indireta frente a pelo menos um dos microrganismos indicadores utilizados, sugerindo terem produzido substâncias semelhantes a bacteriocinas. Três destas cepas foram caracterizadas e identificadas como pertencentes ao gênero Lactobacillus sp