Anatomical and developmental aspects of leaf galls induced by Schizomyia macrocapillata Maia (Diptera: Cecidomyiidae) on Bauhinia brevipes Vogel (Fabaceae)

Samples of healthy leaves and galls induced by Schizomyia macrocapillata Maia on Bauhinia brevipes Vogel were submitted to routine techniques to investigate gall anatomy and development. Pouch galls are induced on the abaxial surface of unfolded immature leaves, and become spheroid with long reddish hairs covering their external surface. Galls occur isolated or coalesce when in larger numbers. Gall development was divided into six phases: 1) initiation; 2) tissue re-arrangement; 3) tissue differentiation; 4) maturation; 5) growth phase; and 6) dehiscence. This last phase corresponds to gall senescence, which takes place just after the larva exits the chamber to pupate. An important developmental phase of tissue reorientation was recorded after the initiation phase. The presence of hyphae close to the covering layer characterizes this gall as an ambrosia gall and the feeding mode of the gall migde is discussed. Few hyphae were found during the first developmental phases and fungi may play an important role during gall morphogenesis. Neoformed trichomes may provide not only photoprotection but also protection against natural enemies and water loss. The neoformation of phloematic bundles suggests host manipulation and indicates the establishment of a deviating sink.

Patterns of induced abortion in urban area of Southeastern region, Brazil

OBJECTIVE: To assess the behavior of induced abortion as a function of certain demographic variables, for the population of fertile women (15 to 49 years old) residing in the Vila Madalena subdistrict S. Paulo (Brazil). MATERIAL AND METHOD: Two population samples were selected. One sample, with 996 women, investigated the incidence of induced abortions during 1987, using the RRT. In the other, involving 1,004 women, the same information was detected through a conventional approach. In both samples, the induced abortion occurring during the reproductive life was recorded in direct fashion. Though this analysis refers only to information about past abortions, that is by 2,000 women -, it should be noted that it is exactly the RRT that lends credibility to the found or results given results. CONCLUSION: The analysis furnishes evidence showing that single women, young women between the ages of 15 and 19, women who have not had live births, women who have a number of children below the expected ideal, women who use contraceptive methods (especially inefficient ones) and women who do not have any restrictions as to abortion constitute the categories most inclined to resort to induced abortion. This grouping suggests the existence of interrelationships between categories, that is, each of these categories is probably composed primarily of the same women, those who are at the beginning of their reproductive lives.

Contextual determinants of induced abortion: a panel analysis

ABSTRACT OBJECTIVE Analyze the contextual and individual characteristics that explain the differences in the induced abortion rate, temporally and territorially. METHODS We conducted an econometric analysis with panel data of the influence of public investment in health and per capita income on induced abortion as well as a measurement of the effect of social and economic factors related to the labor market and reproduction: female employment, immigration, adolescent fertility and marriage rate. The empirical exercise was conducted with a sample of 22 countries in Europe for the 2001-2009 period. RESULTS The great territorial variability of induced abortion was the result of contextual and individual socioeconomic factors. Higher levels of national income and investments in public health reduce its incidence. The following sociodemographic characteristics were also significant regressors of induced abortion: female employment, civil status, migration, and adolescent fertility. CONCLUSIONS Induced abortion responds to sociodemographic patterns, in which the characteristics of each country are essential. The individual and contextual socioeconomic inequalities impact significantly on its incidence. Further research on the relationship between economic growth, labor market, institutions and social norms is required to better understand its transnational variability and to reduce its incidence.

Trypanosoma cruzi: modification of alkaline phosphatase activity induced by trypomastigotes in cultured human placental villi

Human term placental villi cultured ''in vitro" were maintained with bloodstream forms of Trypanosoma cruzi during various periods of time. Two different concentrations of the parasite were employed. Controls contained no T. cruzi. The alkaline phosphatase activity was determined in placental villi by electron microscopy and its specific activity in the culture medium by biochemical methods. Results showed that the hemoflagellate produces a significant decrease in enzyme activity as shown by both ultracytochemical and specific activity studies and this activity was lower in cultures with high doses of parasites. The above results indicate that the reduction in enzyme activity coincides with the time of penetration and proliferation of T. cruzi in mammalian cells. These changes may represent an interaction between human trophoblast and T. cruzi.

Changes in pentobarbital induced sleeping-time in mice infected with Schistosoma mansoni and immunosuppressed

To evaluate whether the intensity of the hepatic granulomatous response induced by S. mansoni eggs plays a role in drug metabolism, mice were infected with 40 cercariae and tested to assess the sodic pentobarbital induced sleeping-time. To decrease the inflammatory reaction the animals were irradiated with 400 Rad or received azathioprine, 20mg/kg, 3 times a week, for 4 weeks, respectively in or beginning in the 33th post-infection day. In infected animals receiving azathioprine the area of the hepatic granulomas was smaller and the sleeping-time was similar to that of non-infected ones (controls). In mice infected and irradiated the granuloma dimensions were similar to those of animals only infected, in these two latter groups of animals, the sleeping-time was more prolonged than that of the control animals. These results show that: 1) mice with unaltered hepatic granulomatous reaction show reduction in metabolism of sodic pentobarbital; 2) granulomatous response diminished by azathioprine does not interfere with the capacity of metabolism of the anesthetic drug.

Cardiac sympathetic-parasympathetic balance in rats with experimentally-induced acute chagasic myocarditis

To clarify the mechanism responsible for the transient sinus tachycardia in rats with acute chagasic myocarditis, we have examined the cardiac sympathetic-parasympathetic balance of 29 rats inoculated with 200,000 parasites (Trypanosoma cruzi). Sixteen infected animals and 8 controls were studied between days 18 and 21 after inoculation (acute stage). The remaining 13 infected animals and 9 controls were studied between days 60 and 70 after inoculation (sub-acute stage). Under anesthesia (urethane 1.25 g/kg), all animals received intravenous atenolol (5 mg/kg) and atropine (10 mg/kg). Acute stage: The baseline heart rate of the infected animals was significantly higher than that of the controls (P < 0.0001). The magnitude of the negative chronotropic response to atenolol was 4 times that of the controls (P < 0.00001). This response correlated with the baseline heart rate (r= - 0.72, P < 0.001). The heart rate responses to the beta-blocker and to atropine, of the infected animals studied during the sub-acute stage, were not different from controls. These findings suggest that cardiac sympathetic activity is transiently enhanced and cardiac parasympathetic activity is not impaired, in rats with acute chagasic myocarditis. The transient predominance of cardiac sympathetic activity could explain, in part, the sinus tachycardia observed in the acute stage of experimentally-induced chagasic myocarditis.

Leishmania (Viannia) panamensis - induced cutaneous leishmaniasis in susceptible and resistant mouse strains

We studied the susceptibility to Leishmania (Viannia) panamensis in strains of mice. The C57BL/6 strain was resistant and showed self-controlled lesion at the injected foot pad. The BALB/c and DBA/2J strains were susceptible and showed a foot swelling that started day 20 post-infection and progressed to a tumour-like lesion in later period of observation. The CBA/HJ strain was found to be of intermediary resistance. In contrast to other known cutaneous leishmaniasis in mice, the lesion in L. (V.) panamensis-infected mice was restricted to the inoculation site in the skin. In addition, we studied the development of cellular response and antibodies against Leishmania antigen in BALB/c and C57BL/6 strains. The proliferative response of lymph node cells against L. (V.) panamensis antigen was biphasic in both strains. An initial response was seen on day 20, followed by a refractory period between 40 and 80 days and a second response around fourth month post-infection. The response in the latter period was higher in C57BL/6 strain than in BALB/c strain. BALB/c strain presented much higher anti-Leishmania antibody level than C57BL/6 strain. The model and the correlation of immunological variables and the course of the infection are discussed.

Immune responses induced by a Leishmania (Leishmania) amazonensis recombinant antigen in mice and lymphocytes from vaccinated subjects

In the search for Leishmania recombinant antigens that can be used as a vaccine against American Cutaneous Leishmaniasis, we identified a Leishmania (Leishmania) amazonensis recombinant protein of 33 kD (Larp33) which is recognized by antibodies and peripheral blood leukocytes (PBL) from subjects vaccinated with Leishvacin ®, Larp33 was expressed in Escherichia coli after cloning of a 2,2 kb Sau3A digested genomic fragment of L. (L.) amazonensis into the pDS56-6 His vector. Immunoblotting analysis indicated that Larp33 corresponds to an approximately 40-kD native protein expressed in promastigotes of L.(L.) amazonensis and L. (Viannia) braziliensis. Northern blots of total RNA also demonstrated that the gene coding for this protein is expressed in promastigotes of the major lineages of Leishmania causing American Cutaneous Leishmaniasis. Larp33 induced partial protection in susceptible mouse strains (BALB/c and C57BL/10) against L. (L.) amazonensis after vaccination using Bacille Calmette-Guerin (BCG) as adjuvant. In vitro stimulation of splenocytes from BALB/c protected mice with Larp33 elicited the secretion of IL-2 and IFN-g, suggesting that a Th1 cell-mediated protective response is associated with the resistance observed in these mice. As revealed by its immunogenic and antigenic properties, this novel recombinant antigen is a suitable candidate to compose a vaccine against cutaneous leishmaniasis

INTRACELLULAR Leishmania amazonensis KILLING INDUCED BY THE GUANINE NUCLEOSIDE 8-BROMOGUANOSINE

In this study we investigated the effect of 8-Bromoguanosine, an immunostimulatory compound, on the cytotoxicity of macrophages against Leishmania amazonensis in an in vitro system. The results showed that macrophages treated with 8-Bromoguanosine before or after infection are capable to reduce parasite load, as monitored by the number of amastigotes per macrophage and the percentage of infected cells (i.e. phagocytic index). Since 8-Bromoguanosine was not directly toxic to the promastigotes, it was concluded that the ribonucleoside induced macrophage activation. Presumably, 8-Bromoguanosine primed macrophages by inducing interferon alpha and beta which ultimately led to L. amazonensis amastigote killing. The results suggest that guanine ribonucleosides may be useful to treat infections with intracellular pathogens.

Heart rate responses to a muscarinic agonist in rats with experimentally induced acute and subacute chagasic myocarditis

We administered arecoline to rats, with experimentally induced chagasic myocarditis, in order to study the sinus node sensitivity to a muscarinic agonist. Sixteen month old rats were inoculated with 200,000 T. cruzi parasites ("Y" strain). Between days 18 and 21 (acute stage), 8 infected rats and 8 age-matched controls received intravenous arecoline as a bolus injection at the following doses: 5.0, 10.0, 20.0, 40.0, and 80.0 mug/kg. Heart rate was recorded before, during and after each dose of arecoline. The remaining 8 infected animals and 8 controls were subjected to the same experimental procedure during the subacute stage, i.e., days 60 to 70 after inoculation. The baseline heart rate, of the animals studied during the acute stage (349 ± 68 bpm, mean ± SD), was higher than that of the controls (250 ± 50 bpm, p < 0.005). The heart rate changes were expressed as percentage changes over baseline values. A dose-response curve was constructed for each group of animals. Log scales were used to plot the systematically doubled doses of arecoline and the induced-heart rate changes. The slope of the regression line for the acutely infected animals (r = - 0.99, b =1.78) was not different from that for the control animals (r = - 0.97, b = 1.61). The infected animals studied during the subacute stage (r = - 0.99, b = 1.81) were also not different from the age-matched controls (r = - 0.99, b = 1.26, NS). Consequently, our results show no pharmacological evidence of postjunctional hypersensitivity to the muscarinic agonist arecoline. Therefore, these results indirectly suggest that the postganglionic parasympathetic innervation, of the sinus node of rats with autopsy proved chagasic myocarditis, is not irreversibly damaged by Trypanosoma cruzi.

Some ultrastructural superficial changes in house fly (Diptera: Muscidae) and blow fly (Diptera: Calliphoridae) larvae induced by eucalyptol oil

The ultrastructural superficial changes in third instar house fly (Musca domestica) and blow fly (Chrysomya megacephala) induced by eucalyptol oil were observed using scanning electron microscopy. Dipped in 0.902 g/ml eucalyptol for 30 sec, the larvae integument of both species showed significant aberrant appearance of the body surface, particularly swelling integument, bleb formation, partial breach and deformation of spines.

DISTINCT CELLULAR MIGRATION INDUCED BY Leishmania infantum chagasi AND SALIVA FROM Lutzomyia longipalpis IN A HEMORRHAGIC POOL MODEL

Recruitment of a specific cell population after Leishmania infection can influence the outcome of the disease. Cellular migration in response to Leishmania or vector saliva has been reported in air pouch model, however, cellular migration induced by Leishmania associated with host's blood and vector saliva in this model has not been described. Herein we investigated cellular migration into air pouch of hamster after stimulation with combination of L. chagasi and host's blood and Lutzomyia longipalpis saliva. Migration induced by saliva was 3-fold more than those induced by L. chagasi alone. Additionally, L. chagasi associated with blood and saliva induced significantly even more leukocytes into air pouch than Leishmania alone. L. chagasi recruited a diverse cell population; however, most of these cells seem to have not migrated to the inflammatory exudate, remaining in the pouch lining tissue. These results indicate that L. chagasi can reduce leukocyte accumulation to the initial site of infection, and when associated with vector saliva in the presence of blood components, increase the influx of more neutrophils than macrophages, suggesting that the parasite has developed a strategy to minimize the initial inflammatory response, allowing an unlimited progression within the host. This work reinforces the importance of studies on the salivary components of sand fly vectors of leishmaniasis in the transmission process and the establishment of the infection.

CD19 LYMPHOCYTE PROLIFERATION INDUCED BY Bifidobacterium animalis subsp. lactis IN C57BL/6 MICE EXPERIMENTALLY INFECTED WITH Toxoplasma gondii

Toxoplasmosis is frequently acquired through the oral route by the ingestion of cysts or oocysts of Toxoplasma gondii. Once ingested, the parasites penetrate the intestinal epithelial cells and rapidly disseminate to all organs in the host. During T. gondii infection, the intestinal microbiota plays an important role in stimulating a protective immune response against the parasite. In this sense the use of probiotics is worthy of note since they are live microorganisms that have beneficial effects on the host through stimulation of the immune response that can be important in the control of T. gondii proliferation and dissemination in the host. In the present study, the action of the probiotic Bifidobacterium animalis subsp. lactis was investigated in C57BL/6 mice infected with oocysts of ME49 strain of T. gondii. The probiotic had an immunomodulatory action, inducing CD19 lymphocyte proliferation and consequently increasing anti-T. gondii antibody level.Bifidobacterium animalis subsp. lactisprovided protection in supplemented mice, compared to the control group. In addition, supplemented animals had milder inflammatory process in the small intestine, indicating that the probiotic protects the intestinal mucosa during infection with T. gondii. It was concluded that the probioticB. animalis subsp. lactis induces humoral immune response capable of providing protection against T. gondii infection.

Cytogenetics of Triatominae: III - A study on male sterility induced through hybridization of Triatoma sórdida and Triatoma pseudomaculata

Males from bilateral crosses between Triatoma sórdida and Triatoma pseudomaculata were unable to give offspring, as shown by subsequent backcrosses (BC) between hybrid males and parental females. This kind of sterility indueed through interspecific hybridization seems to be due to lack of sperm migration from the bursa copulatrix to the spermateca, thus suggesting primarily failure on the part of hybrid males to produce and/or to incorporate male accessory secretions into the spermatophore bulb. Addicional proof that sterility induced in hybrid males is at the sperm level has been afforded by the spermatogenesis herein studied. The anomalous processes like; 1) prophases of spermatogonia with the chromosomes scattered in the cytoplasm, 2) first metaphases with unpaired tetrades, 3) spermatids differing in size and 4) spermatozoa of abnormal shape and generdlly of giant size, can be taken as an indicator of the degree of departure from the normal course of spermatogenesis.