Moderate physical exercise and ATP modulate the P2X7 receptor and improve cisplatin-induced gastric emptying delay in rats

Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.

Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.

Antinociceptive and anti-inflammatory activities of a triterpene-rich fraction from Himatanthus drasticus

Himatanthus drasticus (Mart.) Plumel belongs to the Apocynaceae family and the latex from its trunk bark (Hd) is known as "janaguba milk". This latex is widely used in Northeast Brazil, mainly in the Cariri region, for its gastroprotective, anti-inflammatory, and antitumor properties. The objective of this study was to investigate a triterpene-rich fraction (FJNB) from H. drasticus latex on acute models of nociception and inflammation and to clarify its mechanisms of action. Wistar rats or Swiss mice were subjected to the carrageenan-induced paw edema test or the formalin test, respectively, after the acute oral treatment with FJNB. The inflamed paws from the carrageenan-induced paw edema and formalin tests were processed for histological and immunohistochemical assays, respectively. The results were analyzed by ANOVA and considered significant at P<0.05. FJNB (10 mg/kg) decreased the paw edema by 25% at the 3rd h after the carrageenan injection. Indomethacin, used as reference, inhibited the paw edema by 59% at the same time-point. In the formalin test, FJNB inhibited the 1st phase by 27, 49, and 52% and the 2nd phase by 37, 50, and 67%, at the doses of 1, 5, and 10 mg/kg, respectively. In addition, FJNB significantly inhibited the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and the inflammatory cytokine tumor necrosis factor (TNF)-alpha. The histone deacetylase (HDAC) expression and the transcription factor nuclear factor kappa (NF-kB) were also inhibited at the same doses. In conclusion, the FJNB inhibitory actions on iNOS, COX-2, TNF-α, HDAC, and NF-kB could be involved with the drug anti-inflammatory activity.

Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

Muscle strength imbalance between hamstring and quadriceps among professional dancers / Desequilíbrio muscular entre isquiotibiais e quadríceps entre dançarinos profissionais

The aim of this study was to evaluate the unilateral strength in knee flexion and extension, and the Hamstring/Quadriceps Ratio (H/Q Ratio), in dominant and non-dominant lower limbs in professional dancers. This was a cross-sectional study, carried out with 12 health adults (27.5±1.27years, 66.6±3.11kg, 173±0.02cm, 22.1±0.51kg/m2), professional dancers of a national company. The volunteers, after physical measurements, were submitted to a 1 Repetition Maximum (1RM) test, unilaterally, in both lower limbs at Flexor and Extensor Bench seat exercises. After 1 week, a 1RM retest was carried out to confirm the real total load for each limb. The torque and H/Q Ratio were calculated unilaterally. In knee extension, the dominant limb presented strength 18.77% higher than nondominant limb (p<0.01), and in knee flexion, the strength of the dominant limb was 16.38% higher than the non-dominant limb (p=0.04). The H/Q Ratio was higher in the non-dominant limb 90.12 ± 0.22% than dominant limb 86.36±0.37% (p=0.04). The results showed difference in the strength between dominant and non-dominant members in both movements, knee flexion and extension. The H/Q Ratio presented values that evidenced imbalance in lower limbs. The population of dancers under study presented risk for injuries in lower limbs, requiring a specific training intervention.

O objetivo deste estudo foi avaliar a força de flexão e extensão do joelho, de forma unilateral, e a relação Isquiotibiais-Quadriceps (relação I/Q), nos membros inferiores dominantes e não dominantes de dançarinos profissionais. Este foi um estudo transversal, realizado com 12 dançarinos profissionais adultos saudáveis (27.5±1.27anos, 66.6±3.11kg, 173±0.02cm, 22.1±0.51kg/m2), de uma empresa de dança brasileira. Após as avaliações antropométricas, os indivíduos foram submetidos ao teste de uma repetição máxima (1RM) na cadeira extensora e flexora, unilateralmente, em ambos os membros inferiores. Após uma semana, um reteste de 1RM foi realizado para confirmar a carga total para cada membro. O torque e relação I/Q foram calculados de forma unilateral. Em extensão do joelho do membro dominante apresentou força 18,77% superior ao membro não dominante (p <0,01), e na flexão do joelho, a força do membro dominante foi 16,38% maior do que a força do membro não dominante (p = 0,04). A Relação I/Q foi maior no membro não-dominante 90.12 ± 0.22% do que no membro dominante 86.36±0.37% (p = 0,04). Os resultados mostraram diferença na força entre os membros dominantes e não dominantes em ambos os movimentos, na flexão e extensão do joelho. A relação I/Q apresentou valores que evidenciaram desequilíbrio nos membros inferiores. A população de dançarinos em estudo apresenta risco de lesões nos membros inferiores, necessitando de uma intervenção formação específica.

Estudo preliminar toxicológico, antibacteriano e fitoquímico do extrato etanólico das folhas de Jatropha mollissima (Pohl) Baill. (pinhão-bravo, Euphorbiaceae), coletada no Município de Tauá, Ceará, Nordeste Brasileiro / Toxicological, antibacterial, and phytochemical preliminary study of the ethanolic extract of Jatropha mollissima (Pohl) Baill (pinhão-bravo, Euphorbiaceae) leaves, collected in Tauá, Ceará, Northeastern Brazil

RESUMO A cada dia, cepas bacterianas estão tornando-se resistentes a diversos antibióticos, o que faz necessária a busca de novas substâncias eficazes para o tratamento de doenças. Desta forma, este trabalho reporta o estudo preliminar toxicológico, antibacteriano e fitoquímico do extrato etanólico das folhas de Jatropha mollissima (pinhão-bravo, Euphorbiaceae), coletada no Município de Tauá, Ceará, Nordeste Brasileiro. Inicialmente, realizou-se o teste de toxicidade do extrato contra Artemia salina. Na sequencia, foi realizado o ensaio antibacteriano contra quatro cepas bacterianas Gram-negativas (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Hafnia alvei ATCC 51873, Klebsiella pneumoniae ATCC 13883) e uma cepa Gram-positiva (Enterococcus faecalis ATCC 29212). Finalmente, fez-se a análise fitoquímica preliminar do extrato ativo para detecção das principais classes de metabólitos especiais. Como resultado, o extrato etanólico das folhas de J. mollissima se mostrou tóxico para Artemia salina, pois apresentou CL50 igual a 406,02 μg/mL. Quanto à ação antibacteriana, o extrato se mostrou ativo contra a bactéria Gram-positiva Enterococcus faecalis ATCC 29212, apresentando moderada atividade antibacteriana (halo de inibição igual a 7,03 mm). Evidenciou-se no extrato bioativo a presença de cumarinas, fenóis, taninos, flavonoides (flavonóis e flavanonas), alcaloides e esteroides, ambas as classes reportadas como antimicrobianos. Portanto, esse extrato tem potencial para ser usado na produção de fármacos contra infecções causadas por bactérias Gram-positivas. No entanto, as informações direcionam estudos futuros para o isolamento e identificação dos compostos bioativos, monitorados sob a ação antibacteriana mais expressiva.

ABSTRACT Each day, bacterial strains are becoming more resistant to various antibiotics, which requires the search for new effective substances for the treatment of diseases. Thus, this study reports the toxicological, antibacterial, and phytochemical preliminary study of the ethanolic extracts of Jatropha mollissima (pinhão-bravo, Euphorbiaceae) leaves, collected in Tauá, Ceará, Northeast of Brazil. Initially, we performed the toxicity testing of the extract against Artemia salina. Then, we conducted the antibacterial assay against four Gram-negative bacterial strains (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Hafnia alvei ATCC 51873, Klebsiella pneumoniae ATCC 13883), and one Gram-positive strain (Enterococcus faecalis ATCC 29212). Finally, we carried out the preliminary phytochemical analysis of the active extract to detect the main classes of special metabolites. As a result, the ethanolic extract of J. mollissima leaves was toxic to Artemia salina, because it presented LC50 equal to 406.02 µg/mL. Regarding antibacterial action, the extract was active against the Gram-positive bacteria Enterococcus faecalis ATCC 29212, with moderate antibacterial activity (inhibition zone equal to 7.03 mm). The bioactive extract had the presence of coumarins, phenols, tannins, flavonoids (flavanols and flavonones), alkaloids and steroids, both classes reported as antimicrobials. Therefore, this extract has the potential to be used in the production of drugs against infections caused by Gram-positive bacteria. However, these information require further studies for the isolation and identification of bioactive compounds, monitored under the more expressive antibacterial action.

Compounds used to produce cloned animals are genotoxic and mutagenic in mammalian assays in vitro and in vivo

The compounds 6-dimethylaminopurine and cycloheximide promote the successful production of cloned mammals and have been used in the development of embryos produced by somatic cell nuclear transfer. This study investigated the effects of 6-dimethylaminopurine and cycloheximide in vitro, using the thiazolyl blue tetrazolium bromide colorimetric assay to assess cytotoxicity, the trypan blue exclusion assay to assess cell viability, the comet assay to assess genotoxicity, and the micronucleus test with cytokinesis block to test mutagenicity. In addition, the comet assay and the micronucleus test were also performed on peripheral blood cells of 54 male Swiss mice, 35 g each, to assess the effects of the compounds in vivo. The results indicated that both 6-dimethylaminopurine and cycloheximide, at the concentrations and doses tested, were cytotoxic in vitro and genotoxic and mutagenic in vitro and in vivo, altered the nuclear division index in vitro, but did not diminish cell viability in vitro. Considering that alterations in DNA play important roles in mutagenesis, carcinogenesis, and morphofunctional teratogenesis and reduce embryonic viability, this study indicated that 6-dimethylaminopurine and cycloheximide utilized in the process of mammalian cloning may be responsible for the low embryo viability commonly seen in nuclear transfer after implantation in utero.

Time motion analysis of football (soccer) referees during official matches in relation to the type of fluid consumed

The aim of the present study was to determine the effect of volume and composition of fluid replacement on the physical performance of male football referees. Ten referees were evaluated during three official matches. In one match the participants were asked to consume mineral water ad libitum, and in the others they consumed a pre-determined volume of mineral water or a carbohydrate electrolyte solution (6.4 percent carbohydrate and 22 mM Na+) equivalent to 1 percent of their baseline body mass (half before the match and half during the interval). Total water loss, sweat rate and match physiological performance were measured. When rehydrated ad libitum (pre-match and at half time) participants lost 1.97 ± 0.18 percent of their pre-match body mass (2.14 ± 0.19 L). This parameter was significantly reduced when they consumed a pre-determined volume of fluid. Sweat rate was significantly reduced when the referees ingested a pre-determined volume of a carbohydrate electrolyte solution, 0.72 ± 0.12 vs 1.16 ± 0.11 L/h ad libitum. The high percentage (74.1 percent) of movements at low speed (walking, jogging) observed when they ingested fluid ad libitum was significantly reduced to 71 percent with mineral water and to 69.9 percent with carbohydrate solution. An increase in percent movement expended in backward running was observed when they consumed a pre-determined volume of carbohydrate solution, 7.7 ± 0.5 vs 5.5 ± 0.5 percent ad libitum. The improved hydration status achieved with the carbohydrate electrolyte solution reduced the length of time spent in activities at low-speed movements and increased the time spent in activities demanding high-energy expenditure.

Cloning of a novel acidic phospholipase A2 from the venom gland of Crotalus durissus cascavella (Brazilian northeastern rattlesnake)

The phospholipase A2 superfamily encompasses 15 groups that are classified into: secreted PLA2 (sPLA2); cytosolic PLA2 (cPLA2); Ca2+-independent intracellular PLA2 (iPLA2); platelet-activating factor acetylhydrolase (PAF-AH); and lysosomal PLA2. Currently, approximately 700 PLA2 sequences are known, of which 200 are obtained from the venom gland of Crotalinae snakes. However, thus far, little information is available on cloning, purification and structural characterization of PLA2 from Crotalus durisssus cascavela venom gland. In the present work, we report the molecular cloning of a novel svPLA2 from C. d. cascavella (Cdc), a predominant rattlesnake subspecies in northeastern Brazil. The Cdc svPLA2 cDNA precursor is 689 nucleotides long and encodes a protein of 138 amino acid residues, with a calculated molecular mass of approximately 13,847 Da and an estimated isoelectric point of 5.14. Phylogenetic analysis of Crotalinae PLA2 reveals that Cdc PLA2 clustered with other acidic type IIA PLA2 homologues is also present in the venom of North American rattlesnakes. Hitherto, this study presents a novel PLA2 cDNA precursor from C. d. cascavella and data reported herein will be useful for further steps in svPLA2 purification and analysis.

Detection of Toxoplasma gondii DNA in sera samples of mice experimentally infected

Detection of Toxoplasma gondii (T. gondii) DNA in blood can help to diagnose the disease in its acute phase; however, it must be considered that hemoglobin, present in blood, can inhibit polymerase activity, making impracticable the detection of DNA in samples. Mice were experimentally infected via oral route with ME49 and BTU2 strains cysts and RH strain tachyzoites; polymerase chain reaction was used to detect T. gondii DNA in mice sera 18, 24, 48, 96, and 192 hours post infection (PI). Toxoplama gondii DNA was detected in only one animal infected with BTU2 strain, genotype III (isolated from a dog with neurological signs) 18 hours PI. The agent's DNA was not detected in any sample of the other experimental groups. New studies must be carried out to verify the technique sensitivity in researches on this agent's genetic material using sera samples of acute-phase toxoplasmosis patients, especially in cases of immunosuppression.

Detection of Toxoplasma gondii DNA in sera samples of mice experimentally infected

Detection of Toxoplasma gondii (T. gondii) DNA in blood can help to diagnose the disease in its acute phase; however, it must be considered that hemoglobin, present in blood, can inhibit polymerase activity, making impracticable the detection of DNA in samples. Mice were experimentally infected via oral route with ME49 and BTU2 strains cysts and RH strain tachyzoites; polymerase chain reaction was used to detect T. gondii DNA in mice sera 18, 24, 48, 96, and 192 hours post infection (PI). Toxoplama gondii DNA was detected in only one animal infected with BTU2 strain, genotype III (isolated from a dog with neurological signs) 18 hours PI. The agent’s DNA was not detected in any sample of the other experimental groups. New studies must be carried out to verify the technique sensitivity in researches on this agent’s genetic material using sera samples of acute-phase toxoplasmosis patients, especially in cases of immunosuppression

Trypanosomatids in dogs belonging to individuals with chronic chagas'disease living in Botucatu town and surrounding region, São Paulo State, Brazil

Among domestic animals, dogs are considered to be the major reservoirs of trypanosomatids and, due to their proximity to man, the presence of these parasites in dogs is an alert to actions aiming at triatomine control. Fifty dogs (26 males and 24 females), aged from 2 months to 15 years, belonging to 30 chronic Chagas’ disease individuals from 15 different municipalities in the western region of São Paulo State, Brazil, were subjected to blood collection for the following tests: artificial xenodiagnosis, blood culture, and Polymerase Chain Reaction (PCR). Forty-three (86%) out of 50 dogs were positive to at least one of the tests performed; 34 (68%) were positive to xenodiagnosis, 30 (60%) to blood culture, and 25 (50%) to PCR for T. cruzi and/or T. rangeli. Although triatomines were not detected during the intra and peridomiciliary inspections in the dog owners’ residences, the results obtained demonstrate that there is a transmission cycle whereby triatomine vector may be participating in the infection epidemiological chain

Experience d'une formation en epidemiologie de terrain en Afrique: le cours IEIAA

The International Course on Epidemiology and Applied Data Processing in Africa (Cours IEIAA) is a practical 4-week Fre n ch - l a n g u age training course for professional health care personnel wo rking in A f rica. The fi rst course was organ i zed in 1998 by the A s s o c i ation pour l'Aide a la Medecine Preve n t ive (Association for the Promotion of Preve n t ive Medicine). The course organizing committee includes a pedagogical director and a faculty of field epidemiology experts. Course activities are designed to give attendees competency in epidemiology; biostatistics; computer techniques and communication. Attendance is funded mainly through education grants from the French Foreign Affairs Ministry; WHO; UNICEF; Belgian Te chnical Cooperat i o n ; Swiss Te chnical Cooperat i o n ; and German GTZ. Based on 7 ye a rs of ex p e ri e n c e; c o n s i d e ration is now being given to transforming this course into a tutorial Field Epidemiology Training Program modeled after those now operating in Ghana and Uganda [TEPHINET members Programs located in Africa]

Anti-leptospirose agglutinins in equine sera, from São Paulo, Goias, and Mato Grosso do Sul, Brazil, 1996-2001

Equine leptospirosis can present a non-symptomatic form, an acute clinical form, or even develop chronically, causing reproductive alterations, such as abortion and recurrent uveitis. Since the prevalence of leptospirosis in several countries and regions is widely reported, the objective of this study was to verify the prevailing equine leptospirosis in different regions of Brazil. Sera from 1402 blood samples from horses of different age, sex, breed, and purpose were examined. These samples came from southeastern and central west states of Brazil. The method utilized was the Microscopic Agglutination Test (MAT), with 12 different Leptospira serovars. From the sera tested, 754 (54 percent) were positive for one (385) or more (372) serovars. These results were higher when compared to national and international levels. The most commonly found serovars were icterohaemorrhagiae (37.01 percent), suggesting exposure to rodents, castellonis (16.97 percent), and djasiman (15.19 percent). There were significant differences of reagents between sexes, and a tendency toward higher positivity with age. Distribution of sera-reagents related to aptitude showed a markedly higher value for work animals than for sporting ones. Higher rates were found for animals with undefined breed. There were no significant differences related to regional origin. As an indication of multiple exposure, significant associations were observed between the following serovars: castellonis and djasiman; castellonis and grippotyphosa; castellonis and copenhageni; castellonis and icterohaemorrhagiae; castellonis and pomona; canicola and pomona; canicola and djasiman; djasiman and copenhageni; icterohaemorrhagiae and djasiman; icterohaemorrhagiae and pyrogenes; copenhageni and pomona. These results showed the necessity of further studies on the epidemiology of this disease in equines and its relationship to human illness.

Immune response induced in mice oral immunization with cowpea severe mosaic virus

There is increasing interest in the immune response induced by plant viruses since these could be used as antigen-expressing systems in vaccination procedures. Cowpea severe mosaic virus (CPSMV), as a purified preparation (300 g of leaves, 2 weeks post-inoculation), or crude extract from cowpea (Vigna unguiculata) leaves infected with CPSMV both administered by gavage to Swiss mice induced a humoral immune response. Groups of 10 Swiss mice (2-month-old females) were immunized orally with 10 daily doses of either 50 æg viral capsid protein (boosters of 50 æg at days 21 and 35 after immunization) or 0.6 mg protein of the crude extract (boosters of 0.6 mg at days 21 and 35 after immunization). Anti-CPSMV antibodies were quantified by ELISA in pooled sera diluted at least 1:400 at days 7, 14, 21, 28, 35 and 42 after the 10th dose. IgG and IgA against CPSMV were produced systemically, but IgE was not detected. No synthesis of specific antibodies against the proteins of leaf extracts from V. unguiculata, infected or not with CPSMV, was detected. The use of CPSMV, a plant-infecting virus that apparently does not induce a pathogenic response in animals, induced a humoral and persistent (at least 6 months) immune response through the administration of low antigen doses by gavage. These results raise the possibility of using CPSMV either as a vector for the production of vaccines against animal pathogens or in quick and easy methods to produce specific antisera for viral diagnosis

Interference of propylene glycol with the hole-board test

Experimental drugs and/or plant extracts are often dissolved in solvents, including propylene glycol. Nevertheless, there is evidence for psychoactive properties of this alcohol. In this study we found that in the hole-board test 10 percent propylene glycol did not modify the head-dipping behavior. However, 30 percent propylene glycol induced an increase in the number of head-dips (46.92 + or - 2.37 compared to 33.83 + or - 4.39, P<0.05, ANOVA/Student-Newman-Keuls), an effect comparable to that obtained with 0.5 mg/kg diazepam (from 33.83 + or - 4.39 to 54 + or - 3.8, P<0.01, ANOVA/Student-Newman-Keuls). These results demonstrate that 30 percent propylene glycol has significant anxiolytic effects in this model and therefore cannot be used as an innocuous solvent

Short duration of neutralizing antibody titers after pre-exposure rabies vaccination with suckling mouse brain vaccine

The human anti-rabies pre-exposure treatment currently used in Brazil, employing a 1-ml dose of suckling mouse brain vaccine (SMBV) administered on days 0, 2, 4 and 28, was compared to an alternative treatment with two 1 ml-doses on day 0, and one 1 ml-dose injected on days 7 and 21. The latter induced higher virus-neutralizing antibody (VNA) titers on day 21. Both Brazilian rabies vaccines produced with PV or CVS rabies virus strains were tested. Two additional volunteer vaccinee groups, receiving the pre-exposure and the abbreviated post-exposure schedules recommended by the WHO using cell-culture vaccine (CCV) produced with PM rabies virus strain, were included as reference. The VNA were measured against both PV and CVS strains on days 21, 42 and 180 by the cell-culture neutralization microtest. The PV-SMBV elicited higher seroconversion rates and VNA by day 21 than the CVS-SMBV. Both, however, failed to induce a long-term immunity, since VNA titers were <0.5 IU/ml on day 180, regardless of the schedule used. Cell-culture vaccine always elicited very high VNA on all days of collection. When serum samples from people receiving mouse brain tissue were titrated against the PV and CVS strains, the VNA obtained were similar, regardless of the vaccinal strain and the virus used in the neutralization test. These results contrast with those obtained with sera from people receiving PM-CCV, whose VNA were significantly higher when tested against the CVS strain.

Toxoplasma gondii: I.Avaliaçäo da virulência de oito amostras / Toxoplasma gondii: I.Evaluation of the virulence of eight strains

Oito amostras T. gondii - LIV IV, LIV V e S 11 isoladas de suínos, RH e VPS de seres humanos, AS 28 de camundongos, HV III de cäo e CN de gato - foram inoculadas em camundongos suíços albinos e em coelhos com o objetivo de avaliar a virulência e a patogenicidade. As oito amostras apresentaram-se altamente virulentas para camundongos, matando todos os animais que receberam inóculo, via intraperitoneal, de 10 elevado a quarta potência taquizoitas, entre 6,0 e 7,8 dias, em média, após a inoculaçäo. As amostras isoladas mais recentemente, LIV V e HV III (DL50 subscrito de 7 e 15 taquizoítas, respectivamente) foram as mais virulentas. A amostra RH foi a que apresentou a menor virulência, com DL50 subscrito de 3.160 taquizoítas. A amostra LIV V também se mostrou mais virulenta para coelhos, porém, como foram inoculados apenas 2 animais, estudos posteriores devem ser realizados para confimar este achado

Toxoplasma gondii: II.Caracterizaçäo antigênica de taquizoíto de oito amostras / Toxoplasma gondii: II.Tachyzoite antigenic characterization of eigth strains

O amostras de T. gondii - LIV IV, LIV V e S 11 isoladas de suínos, RH e VPS de seres humanos, AS 28 de camundongos, HV III de cäo e CN de gato - foram analisadas com o objetivo de verificar a existência de possíveis diferenças na resposta imune quando inoculadas em coelhos. Através da técnica de ELISA, näo foram constatadas diferenças entre as oito amostras estudadas. Todas as amostras reagiram de forma semelhante com soros homólogos e heterólogos. A suspensäo antigênica, constituída de extrato celular total, mostrou-se eficiente no ELISA teste indireto, já que os soros positivos reagiram fortemente e os soros negativos näo apresentaram reaçäo contra os antígenos testados. A análise das amostras, pela técnica de Western blot, revelou que os isolados de T. gondii compartilham vários antígenos com algumas variaçöes. Dentre as bandas reconhecidas no Western blot, três foram comuns a todas as amostras: a p33 (33-37 kDa), p54 (52-55 kDa) e a p66 (66 kDa). A amostra HV III, isolada recentemente de um cäo, foi a que mais diferiu no perfil antigênico. Essa amostra näo apresentou três antígenos (50, 70 e 75 kDa) presentes nas demais amostras. Apenas dosi antígenos, um de 62 kDa da CN e outro de 67 kDa da LIV IV, foram amostra-específicos