Frequency of parasitic forms in fecal samples of maned wolf in different seasons of the year at the Serra da Canastra National Park, Minas Gerais State, Brazil / [Frequência de formas parasitárias em massas fecais de lobos-guarás em diferentes estações do ano no Parque Nacional da Serra da Canastra, MG]

O Parque Nacional da Serra da Canastra (PNSC), localizado no estado de Minas Gerais, é um importante habitat de inúmeras espécies de animais ameaçados de extinção, como o lobo-guará (Chrysocyon brachyurus). Parasitos de animais selvagens podem representar um problema para os programas de manejo e recuperação de espécies ameaçadas, pois atuam como causa primária ou agravante de inúmeras doenças. Dependendo da época do ano, a suscetibilidade ao parasitismo pode ser maior devido à facilidade de infecção. Com o objetivo de avaliar a frequência de endoparasitos e a sazonalidade dessas parasitoses em diferentes épocas do ano, foram examinadas 103 amostras fecais de lobos-guarás, coletadas no PNSC, durante o período de março de 2017 a agosto de 2019. O número de amostras positivas para pelo menos uma espécie de parasito foi de 47 amostras (45,63%), sendo o outono a estação em que foi encontrada a maior frequência de formas parasitárias, com 60,86% (14/23) de amostras positivas, seguido do inverno, com 52,38% (11/21), verão com 37,5% (15/40), e primavera com 36,84% (7/19). Dentre os parasitos encontrados, Capillaria sp. apresentou a maior frequência, sendo encontrado em 23 amostras (22,33%), seguido de trematódeos, em 15 amostras (14,56%), acantocéfalos, ascarídeos, Trichuris sp. e Ancylostoma sp., em cinco amostras (4,85%), nematoides da superfamília Strongyloidea, Lynxacarus sp., em duas amostras (1,94%), e pentastomídeos em uma amostra (0,97%).(AU)

Evolutionary insights into the genomic organization of major ribosomal DNA in ant chromosomes.

The major rDNA genes are composed of tandem repeats and are part of the nucleolus organizing regions (NORs). They are highly conserved and therefore useful in understanding the evolutionary patterns of chromosomal locations. The evolutionary dynamics of the karyotype may affect the organization of rDNA genes within chromosomes. In this study, we physically mapped 18S rDNA genes in 13 Neotropical ant species from four subfamilies using fluorescence in situ hybridization. Furthermore, a survey of published rDNA cytogenetic data for 50 additional species was performed, which allowed us to detect the evolutionary patterns of these genes in ant chromosomes. Species from the Neotropical, Palearctic, and Australian regions, comprising a total of 63 species from 19 genera within six subfamilies, were analysed. Most of the species (48 out of 63) had rDNA genes restricted to a single chromosome pair in their intrachromosomal regions. The position of rDNA genes within the chromosomes appears to hinder their dispersal throughout the genome, as translocations and ectopic recombination are uncommon in intrachromosomal regions because they can generate meiotic abnormalities. Therefore, rDNA genes restricted to a single chromosome pair seem to be a plesiomorphic feature in ants, while multiple rDNA sites, observed in distinct subfamilies, may have independent origins in different genera.

Prevalência e distribuição espacial da ocorrência de helmintos em primatas não humanos de vida livre no estado do Rio de Janeiro, Brasil / [Prevalence and spatial distribution of the occurrence of helminths in free-living nonhuman primates in the State of Rio de Janeiro, Brazil]

Seiscentos primatas neotropicais foram submetidos a exames post mortem para avaliação da prevalência parasitária de helmintos gastrointestinais. Foram examinados 556 calitriquídeos (Callithrix spp.), 23 bugios (Alouatta guariba), 19 macacos-pregos (Sapajus nigritus), um mico-leão-dourado (Leontopithecus rosalia) e um mico-leão-da-cara-dourada (Leontopithecus chrysomelas). Do total de 600 animais, foram encontrados espécimes parasitos pertencentes aos filos Acanthocephala, Nemathelmintes e Platyhelminthes (classes Trematoda e Cestoda) em 110 primatas. A prevalência de primatas positivos para, pelo menos, uma espécie de helminto foi de 18,3% (110/600), sendo destes 83,6% (92/110) calitriquídeos, 8,2% (9/110) bugios, 6,4% (7/110) macacos-pregos, 0,9% (1/110) mico-leão-dourado e 0,9% (1/110) mico-leão-da-cara dourada. Em 80,4% (74/92) dos calitriquídeos foram encontrados nematoides Primasubulura sp. e em 1,1% (1/92) nematoides Trypanoxyuris callithrix, em 26,1% (24/92) acantocéfalos (Pachysentis sp.) e em 5,4% (5/92) digenéticos (Platynosomum sp.); em 77,8% (7/9) dos bugios foram encontrados nematoides (Trypanoxyuris minutus), em 11,1% (1/9) acantocéfalos (Pachysentis sp.) e em 11,1% (1/9) cestoides (Bertiella sp.); em 14,3% (1/7) dos macacos-pregos foram encontrados nematoides (Physaloptera sp.), em 28,6% (2/7) acantocéfalos (Prostenorchis sp.) e em 14,3% (1/7) digenéticos (Platynosomum sp.) e no mico-leão-da-cara-dourada foram encontrados acantocéfalos (Prostenorchis sp.). Foi realizado o georreferenciamento dos pontos de encontro dos cadáveres para pontuar a distribuição dos helmintos por região.(AU)

Six hundred neotropical primates underwent postmortem examinations to evaluate the parasitic prevalence of gastrointestinal helminths. Fifty-five callitrichids tamarins (Callithrix spp.), 23 howlers (Alouatta guariba), 19 nail monkeys (Sapajus nigritus), a golden lion tamarin (Leontopithecus rosalia) and a golden-faced lion tamarin (Leontopithecus chrysomelas) were examined. Parasitic specimens belonging to phylums Acantocephala, Nemathelmintes and Platyhelmintes (Trematoda and Cestoda Classes) were found. The prevalence of primates positive for at least one species of helminth was 18.3% (110/600), of which 83.6% (92/110) callitrichids, 8.2% (9/110) howler monkeys, 6.4% (7/110) capuchin monkeys, 0.9% (1/110) golden lion tamarin and 0.9% (1/110) golden faced lion tamarin. In 80.4% (74/92) of callitrichids nematodes (Primasubulura sp.) were found, and in 1.1% (1/92) nematodes (Trypanoxyuris callithricis), in 26.1% (24/92) acanthocephalus (Pachysentis sp.) and 5.4% (5/92) digenetics (Platynosomum sp.); in 77.8% (7/9) of howler monkeys presented nematodes (Trypanoxyuris minutus), 11.1% (1/9) acanthocephalus (Pachysentis sp.) and 11.1% (1/9) cestoids (Bertiella sp.); in 14.3% (1/7) of capuchin monkeys presented nematodes (Physaloptera sp.), 28.6% (2/7) acanthocephalus (Prostenorchis sp.) and 14.3% (1/7) digenetics (Platynosomum sp.) and in the golden-faced lion tamarin acanthocephalus (Prostenorchis sp.) were found. Georreferencing of the meeting points of the cadavers was performed in order to punctuate the distribution of helminths by region.(AU)

The role of progesterone in memory: an overview of three decades.

Memory comprises acquisition, consolidation and retrieval of information. Many substances can influence these different phases. It is well demonstrated that sex hormones, mainly estrogen, impact cognitive function. More recently, progesterone has also been documented as playing an important role in cognition, since it influences brain regions involved in memory. Currently, many women are under hormone treatment, which contain progesterone to decrease the risk of development of endometrial cancer. This affords the opportunity to study the real effects of this hormonal replacement on cognition. There are many contradictory results regarding the role of progesterone in memory. Therefore, the aim of this review was to synthesize these studies using the new perspective of the influence of hormone replacement on cognition in women.

Is lack of sleep capable of inducing DNA damage in aged skin?

Skin naturally changes with age, becoming more fragile. Various stimuli can alter skin integrity. The aim of this study was to evaluate whether sleep deprivation affects the integrity of DNA in skin and exacerbates the effects of aging. Fifteen-month old female Hairless mice underwent 72 h of paradoxical sleep deprivation or 15 days of chronic sleep restriction. Punch biopsies of the skin were taken to evaluate DNA damage by single cell gel (comet) assay. Neither paradoxical sleep deprivation nor sleep restriction increased genetic damage, measured by tail movement and tail intensity values. Taken together, the findings are consistent with the notion that aging overrides the effect of sleep loss on the genetic damage in elderly mice.

Aspectos ecológicos de endoparasitos de piranha vermelha (Pygocentrus nattereri, Kner, 1860) proveniente do rio Cuiabá / Ecological aspects of endoparasites in red piranha (Pygocentrus nattereri Kner, 1860) from Cuiabá river, Mato Grosso, Brazil

This study evaluated the infrapopulations of parasites in red piranha (Pygocentrus nattereri) from theCuiabá river, Mato Grosso, Brazil. One hundred sixty-four specimens of red piranha were captured and examined in the period from October to December, 2007 in Barão de Melgaço, Mato Grosso, Brazil. The parasitism was reviewed by data of prevalence, localization, mean intensity of infection, and abundancefor each group of parasite found. In the examined fishes, nematodes (Eustrongylides spp., Contracaecum spp,. and Procamallanus spp.) and pentastomids were found. Among the examined fishes, 141 (86 percent) presented parasitism by at least one species of parasite; from those, 23 (14 percent) by nematodes identified as Eustrongylides spp., 106 (64.6 percent) by Contracaecum spp., 55 (33.5 percent) by Procamallanus spp., and 90 (54.9 percent) by pentastomids. About the localization of the parasites, from the 23 fishes positive to the infection by Eustrongylides spp., 19 (82.6 percent) presented larvae in the muscle, two (8.7 percent)in the celomatic cavity, and two (8.7 percent) in the air bladder. From the 106 fishes positive to the infection by larvae of Contracacecum spp., 105 (99 percent) presented the celomatic cavity as the locus of parasitism, and one (0.9 percent) presented the parasitism in the air bladder. All the fishes positives to the infection by Procamallanus spp., presented the intestine as parasitism site. From the 90 fishes parasited by pentastomids, 41 (45.6 percent) presented the parasitism in the muscle, 17 (18.9 percent) in the celomatic cavity, and 32 (35.6 percent) in the air bladder. The mean intensities of infection by larvae of Contracaecum spp. and Eustrongylides spp., Procamallanus spp., and pentastomids were 1.04; 3.93; 2.27; and 3.72 parasites per fish, respectively, and the abundance values were 0.14; 2.54; 0.76; and 2.04 parasites per fish, respectively.

In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae)

Human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the Anisakidae family. The present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against Contracaecum sp (Nematoda: Anisakidae). Four hundred live larvae of Contracaecum sp obtained from "traíra" fish (Hoplias malabaricus, Bloch, 1974) were analyzed on 40 Petri dishes (10 larvae each) with the compounds to be tested. The final concentrations tested for each compound were 250, 125, 62.5, and 31.2 µg/mL and the evaluation was carried out at five different times (2, 4, 8, 24, and 48 h). The larvicidal action of geraniol and citronellal was statistically superior (P < 0.005) to the control (1 percent ethanol) at concentrations of 250 and 31.2 µg/mL (geraniol) and 250, 125, and 62.5 μg/mL (citronellal). However, no larvicidal activity was observed at concentrations of 125 and 62.5 µg/mL for geraniol and 31.2 µg/mL for citronellal. When the larvicidal action of geraniol was compared to that of citronellal, the former was found to be statistically superior (P < 0.05) to the latter at concentrations of 250 and 31.2 μg/mL. On the other hand, citronellal was statistically superior (P < 0.005) to geraniol at concentrations of 125 and 62.5 μg/mL. The larval mortality rate in terms of time (hours) was higher for geraniol with the passing of time at the 250 μg/mL concentration. At this concentration (in 48 h) the best larvicidal effect was observed with 90 percent lethality. The larvae were considered to be dead using no motility and loss of structural integrity as parameters. The data indicate that natural terpene compounds should be more explored for antihelminthic activity and can be useful for other studies about anisakiasis treatment.

In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae).

Human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the Anisakidae family. The present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against Contracaecum sp (Nematoda: Anisakidae). Four hundred live larvae of Contracaecum sp obtained from 'traíra' fish (Hoplias malabaricus, Bloch, 1974) were analyzed on 40 Petri dishes (10 larvae each) with the compounds to be tested. The final concentrations tested for each compound were 250, 125, 62.5, and 31.2 microg/mL and the evaluation was carried out at five different times (2, 4, 8, 24, and 48 h). The larvicidal action of geraniol and citronellal was statistically superior (P < 0.005) to the control (1% ethanol) at concentrations of 250 and 31.2 microg/mL (geraniol) and 250, 125, and 62.5 microg/mL (citronellal). However, no larvicidal activity was observed at concentrations of 125 and 62.5 microg/mL for geraniol and 31.2 microg/mL for citronellal. When the larvicidal action of geraniol was compared to that of citronellal, the former was found to be statistically superior (P < 0.05) to the latter at concentrations of 250 and 31.2 microg/mL. On the other hand, citronellal was statistically superior (P < 0.005) to geraniol at concentrations of 125 and 62.5 microg/mL. The larval mortality rate in terms of time (hours) was higher for geraniol with the passing of time at the 250 microg/mL concentration. At this concentration (in 48 h) the best larvicidal effect was observed with 90% lethality. The larvae were considered to be dead using no motility and loss of structural integrity as parameters. The data indicate that natural terpene compounds should be more explored for antihelminthic activity and can be useful for other studies about anisakiasis treatment.

Effect of praziquantel administration on hepatic stereology of mice infected with Schistosoma mansoni and fed a low-protein diet.

A study was undertaken to investigate the effect of administering praziquantel (PZQ), focusing on the liver stereological findings of malnourished mice infected with Schistosoma mansoni. Thirty female Swiss Webster mice (age: 21 days; weight: 8-14 g) were fed either a low-protein diet (8%) or standard chow (22% protein) for 15 days. Five mice in each group were infected with 50 cercariae each of the BH strain (Brazil). PZQ therapy (80 mg/kg body weight, per day) was started on the 50th day of infection and consisted of daily administration for 5 days. Volume density (hepatocytes, sinusoids and hepatic fibrosis) was determined by stereology using a light microscope. Body weight gain and total serum albumin levels were always lower in undernourished mice. Our stereological study demonstrated that treatment increased both volume density of hepatocytes in mice fed standard chow (47.56%, treated group and 12.06%, control) and low-protein chow (30.98%, treated group and 21.44%, control), and hepatic sinusoids [standard chow (12.52%, treated group and 9.06%, control), low-protein chow (14.42%, treated group and 8.46%, control)], while hepatic fibrosis was reduced [standard chow (39.92%, treated group and 78.88%, control) and low-protein chow (54.60%, treated group and 70.10%, control)]. On the other hand, mice fed low-protein chow decreased density volume of hepatocytes and hepatic fibrosis. In conclusion, our findings indicate that treatment with PZQ ameliorates hepatic schistosomiasis pathology even in mice fed a low-protein diet.

Effect of praziquantel administration on hepatic stereology of mice infected with Schistosoma mansoni and fed a low-protein diet

A study was undertaken to investigate the effect of administering praziquantel (PZQ), focusing on the liver stereological findings of malnourished mice infected with Schistosoma mansoni. Thirty female Swiss Webster mice (age: 21 days; weight: 8-14 g) were fed either a low-protein diet (8 percent) or standard chow (22 percent protein) for 15 days. Five mice in each group were infected with 50 cercariae each of the BH strain (Brazil). PZQ therapy (80 mg/kg body weight, per day) was started on the 50th day of infection and consisted of daily administration for 5 days. Volume density (hepatocytes, sinusoids and hepatic fibrosis) was determined by stereology using a light microscope. Body weight gain and total serum albumin levels were always lower in undernourished mice. Our stereological study demonstrated that treatment increased both volume density of hepatocytes in mice fed standard chow (47.56 percent, treated group and 12.06 percent, control) and low-protein chow (30.98 percent, treated group and 21.44 percent, control), and hepatic sinusoids [standard chow (12.52 percent, treated group and 9.06 percent, control), low-protein chow (14.42 percent, treated group and 8.46 percent, control)], while hepatic fibrosis was reduced [standard chow (39.92 percent, treated group and 78.88 percent, control) and low-protein chow (54.60 percent, treated group and 70.10 percent, control)]. On the other hand, mice fed low-protein chow decreased density volume of hepatocytes and hepatic fibrosis. In conclusion, our findings indicate that treatment with PZQ ameliorates hepatic schistosomiasis pathology even in mice fed a low-protein diet.

Effects of low-protein diet on Schistosoma mansoni morphology visualized by morphometry and confocal laser scanning microscopy.

Previous studies have shown that protein deficiencies can hamper both the course of experimental schistosomiasis and normal development of adult worms. To further investigate this relationship, we compared adult male and female Schistosoma mansoni from malnourished and well-fed mice through morphometric and confocal laser scanning microscopy analysis. Swiss mice were fed protein-deficient diets (8%) and infected subcutaneously with approximately 80 S. mansoni cercariae (BH strain, Brazil). Control mice were fed a standard rodent diet (23% protein). The nutritional status was evaluated by body weight gain and albumin values. Mice were sacrificed 63 days post-infection. Recovered worms were stained with hydrochloric carmine and preserved as whole-mounts for bright-field examination and confocal microscopy. The body weight gain and serum albumin concentrations were significantly lower (P < 0.05) in malnourished mice than in controls. In general, all morphometric values of specimens grown in malnourished mice were lower than those of control mice. Schistosome worms grown in malnourished mice had statistically significant differences (P < 0.05) in the reproductive system and tegument than those grown in mice fed standard diets. In female worms, vitelline glands showed few remaining follicles and ovaries lacked mature oocytes. In male parasites, tubercles were fewer in number on the dorsal surface and testicular lobes presented fewer differentiated germinal cells. In summary, we describe novel data supporting the view that low-protein diets may influence the development of adult worms.

Influence of He-Ne laser therapy on the dynamics of wound healing in mice treated with anti-inflammatory drugs.

We determined the effects of helium-neon (He-Ne) laser irradiation on wound healing dynamics in mice treated with steroidal and non-steroidal anti-inflammatory agents. Male albino mice, 28-32 g, were randomized into 6 groups of 6 animals each: control (C), He-Ne laser (L), dexamethasone (D), D + L, celecoxib (X), and X + L. D and X were injected im at doses of 5 and 22 mg/kg, respectively, 24 h before the experiment. A 1-cm long surgical wound was made with a scalpel on the abdomens of the mice. Animals from groups L, D + L and X + L were exposed to 4 J (cm(2))-1 day-1 of He-Ne laser for 12 s and were sacrificed on days 1, 2, or 3 after the procedure, when skin samples were taken for histological examination. A significant increase of collagen synthesis was observed in group L compared with C (168 +/- 20 vs 63 +/- 8 mm(2)). The basal cellularity values on day 1 were: C = 763 +/- 47, L = 1116 +/- 85, D = 376 +/- 24, D + L = 698 +/- 31, X = 453 +/- 29, X + L = 639 +/- 32 U/mm(2). These data show that application of L increases while D and X decrease the inflammatory cellularity compared with C. They also show that L restores the diminished cellularity induced by the anti-inflammatory drugs. We suggest that He-Ne laser promotes collagen formation and restores the baseline cellularity after pharmacological inhibition, indicating new perspectives for laser therapy aiming to increase the healing process when anti-inflammatory drugs are used.

Influence of He-Ne laser therapy on the dynamics of wound healing in mice treated with anti-inflammatory drugs

We determined the effects of helium-neon (He-Ne) laser irradiation on wound healing dynamics in mice treated with steroidal and non-steroidal anti-inflammatory agents. Male albino mice, 28-32 g, were randomized into 6 groups of 6 animals each: control (C), He-Ne laser (L), dexamethasone (D), D + L, celecoxib (X), and X + L. D and X were injected im at doses of 5 and 22 mg/kg, respectively, 24 h before the experiment. A 1-cm long surgical wound was made with a scalpel on the abdomens of the mice. Animals from groups L, D + L and X + L were exposed to 4 J (cm²)-1 day-1 of He-Ne laser for 12 s and were sacrificed on days 1, 2, or 3 after the procedure, when skin samples were taken for histological examination. A significant increase of collagen synthesis was observed in group L compared with C (168 ± 20 vs 63 ± 8 mm²). The basal cellularity values on day 1 were: C = 763 ± 47, L = 1116 ± 85, D = 376 ± 24, D + L = 698 ± 31, X = 453 ± 29, X + L = 639 ± 32 U/mm². These data show that application of L increases while D and X decrease the inflammatory cellularity compared with C. They also show that L restores the diminished cellularity induced by the anti-inflammatory drugs. We suggest that He-Ne laser promotes collagen formation and restores the baseline cellularity after pharmacological inhibition, indicating new perspectives for laser therapy aiming to increase the healing process when anti-inflammatory drugs are used.

Larvas de nematóides de importância zoonótica encontradas em traíras (Hoplias malabaricus bloch, 1794) no município de Santo Antonio do Leverger, MT / Nematode larvae with zoonotical importance found in trairas (Hoplias malabaricus) in Santo Antonio do Leverger, Mato Grosso, Brazil

In order to investigate the prevalence of nematode larvae with zoonotical importance in trairas (Hoplias malabaricus), necropsy exams were done 30 specimes from Santo Antonio do Leverger, Mato Grosso, Brazil. These fishes were collected during drought time and two different nematodes larvae were found - Contracaecum sp. and Eustrongylides sp. - presenting the following prevalence: Contracaecum sp., 73 percent and Eustrongylides sp., 33 percent.

Hermaphrodites and supernumerary testicular lobes in Schistosoma mansoni (Trematoda: Schistosomatidae) analyzed by brightfield and confocal microscopy.

Schistosoma mansoni belongs to the dioecious Schistosomatidae. The occasional observation of males with rudimentary female characteristics is thought to attest the hermaphroditic roots of this parasite. Supernumerary testicular lobes also are recurrently seen in this helminth, but their morphology and origin are elusive. Here, we investigated the morphology of the supernumerary lobes from 15 S. mansoni males and similar structures of 2 females in whole mounts by brightfield and confocal laser scanning microscopy. The follicles in the females were not regarded as testicular lobes, but 1 male had a rudimentary ovary with a residual oviduct posterior to the normal set of testicular lobes and was considered hermaphroditic. In addition, 6 other males contained supernumerary lobes that enclosed fully matured oocytes in variable amounts. In the remaining 8 males, no female characteristics could be seen, and the lobes showed morphologically a more testicular aspect, although this morphology was only confirmed in 1 male where spermatozoids were detected. The process underlying the expression of supernumerary testes or lobes with oocytes is similar and is, at least in part, induced by the host.

Prevalence and pathology of helminths of ciconiiform birds from the Brazilian swamplands.

The prevalence of helminths recovered from 108 birds representing eight species of Ciconiiformes from the Brazilian west-central region are presented. The digeneans Ascocotyle (Phagicola) longa, Clinostomum marginatum, Cotylotretus grandis, Ithyoclinostomum dimorphum, the nematodes Contracaecum multipapillatum, Desmidocercella ardeae, Eustrongylides ignotus, and the cestode Valipora mutabilis were identified. Contracaecum multipapillatum was the most prevalent species and E. ignotus the most pathogenic. Gross lesions due to infections with C. multipapillatum were characterized by ulcerative processes and hyperemia of the mucosa whereas those caused by E. ignotus consisted of perforations of the gastric mucosa and fibrotic tubular lesions in the gastric serosa. Histopathological examinations revealed necrosis and mixed leucocyte infiltrations and discrete compression of the mucosa in C. multipapillatum infections. Destruction of the mucosa and submucosa with the presence of fibrous capsules were observed in E. ignotus infections. Reports of accidental human infections, with severe clinical signs induced by these parasites, indicate the necessity of a proper evaluation of the pathogenicity of helminths of aquatic birds.

Purification and characterization of human hemoglobin: effect of the hemolysis conditions.

Human hemoglobin was isolated and purified by anion exchange chromatography. To isolate hemoglobin, outdated red blood cells (RBC) were transformed into carbonylhemoglobin, by reaction with carbon monoxide, and submitted to washing/centrifugation procedures, to eliminate other plasma proteins. Albumin was quantified in each supernatant, by the bromcresol green method. Hemolysis was performed in three different hypotonic media (water, 0.01 M NaCl and 5 mM Tris/HCl buffer at pH 7.4), at 8 degrees C for 24 h. Sonication for 5 min was also used to lyse RBC. After isolation of hemoglobin, additional purification was carried out by anion exchange chromatography on AG MP-1, Q-SFF and both exchangers. Hemoglobin concentration of hemolysates and of purified solutions were determined by the hemiglobincyanide method. Residual phospholipids were extracted from the four different hemolysates, as well as from the purified hemoglobin solutions, and were analyzed by high performance liquid chromatography. Native and SDS-polyacrylamide gel electrophoresis experiments were performed on purified hemoglobin samples to verify the presence of proteins other than hemoglobin. According to the results, the hemolysis conditions have influence on the purification of hemoglobin.

Effects of experimental infections with larvae of Eustrongylides ignotus Jãegerskiold, 1909 and Contracaecum multipapillatum (Drasche, 1882) Baylis, 1920 in rabbits

Coelhos foram infectados experimentalmente per os com 10 larvas L4 de Eustrogylides ignotus (n= 10) e 50 L3 de Contracaecum multipapillatum (n= 50) coletados em traíras (Hoplias malabaricus) naturalmente parasitadas a fim de se avaliar a patogenicidade induzida por essas espécies e nematóides em mamíferos. Dois coelhos (20%) infectados com E. ignotus morreram antes do quarto dia pós-infecção(um após 51 horas e outro após 78 horas). Seis coelhos (60%) mostraram-se inapetentes até o quinto dia após a infecção experimental. Não foram observados sinais clínicos nos coelhos infectados com C. multipapillatum. A necropsia, oito (80%) mostraram-se positivos para essa espécie de nematóide. Os coelhos infectados com E. ignotus apresentaram congestão gástrica, com formação de hematoma na parede gástrica em 60% dos casos. O peritônio estava congestionado em 20% dos animais, e em 10% dos casos foi observada a presença de abscesso. Todos os animais infectados apresentaram hiperemia da mucosa gástrica com gastrite hemorrágica provocada pela infecção com E. ignotus. Nas infecções com C. multipapillatum, a hiperemia foi seguida por ruptura da mucosa nos locais de fixação do parasito, e na mucosa gástrica observou-se infiltrado leucocitário, com necrose multifocais alcançando a submucosa. Nas infecções com E. ignotus foram constatadas lesões perfurantes em diversos órgãos, principalmente na parede gástrica, pâncreas e fígado, sempre na presença de processo inflamatório misto, intensamente fibrótico, com hemorragia e necrose.

Morphological changes in the reproductive organs of male and female Schistosoma mansoni worms caused by streptozotocin, a drug used to induce diabetes mellitus.

Host metabolic changes have been observed to affect Schistosoma mansoni egg production, worm survival and morphology. We examined worms recovered from streptozotocin-induced diabetic mice by morphometric and morphological analysis through brightfield and confocal laser scanning microscopy. Tegument thickness was slightly smaller and changes in the reproductive organs were observed in 23-30% and consecutively 88-100% of the worms. The testicular lobes had a large diminution of cells in one or more of the lobes, which was associated with a lack of spermatozoids in the seminal vesicle. Ovaries were atrophied, manifested by a complete or large reduction in oocytes but other parts of the reproductive system like the vitelline glands were mainly unaffected. Streptozotocin (STZ) instead of hyperglycaemia caused the degeneration since worms from mice injected with a non-diabetogenic dose, or with nicotinamide to prevent diabetes showed the same alterations. The drug did not affect worm survival or pairing. We conclude that STZ, an alkylating agent that provokes chromosome and DNA damage, changes the morphology of ovaries and testicular lobes in S. mansoni worms in vivo. This is the first report of STZ action in helminths and we suggest that STZ affects oogenesis and spermatogenesis and might cause sterilization of schistosomes.