EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS

Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring.

EVALUATION OF SUBLETHAL EFFECTS OF Ipomoea cairica LINN. EXTRACT ON LIFE HISTORY TRAITS OF DENGUE VECTORS

Plant derived insecticides have considerable potential for mosquito control because these products are safer than conventional insecticides. This study aimed to investigate sublethal activities of Ipomoea carica or railway creeper crude acethonilic extract against life history trait of dengue vectors, Aedes albopictus and Aedes aegypti. The late third instar larvae of Ae. albopictus and Ae. aegypti were exposed to a sublethal dose at LC50 and larvae that survived were further cultured. Overall, Ipomea cairica crude extracts affected the whole life history of both Aedes species. The study demonstrated significantly lower egg production (fecundity) and eggs hatchability (fertility) in Ae. albopictus. The sublethal dose of crude extracts reduced significantly the width of larval head capsule and the wing length of both sexes in both Aedes species. The significance of sublethal effects of I. cairica against Aedes mosquitoes was an additional hallmark to demonstrate further activity of this plant despite its direct toxicity to the larvae. The reduced reproductive capacity as well as morphological and physiological anomalies are some of the effects that make I. cairica a potential candidate to be used as a new plant-based insecticide to control dengue vectors.

Biology of Triatoma carcavalloi Jurberg, Rocha & Lent, 1998 under laboratory conditions

Introduction Triatoma carcavalloi is a wild species that is found in sympatry with Triatoma rubrovaria and Triatoma circummaculata, which are vectors of Trypanosoma cruzi currently found in rural areas of Rio Grande do Sul, Brazil. Methods Fertility was assessed and to determine the incubation period, the eggs were observed until hatching. The first meal was offered to 1st stage nymphs. The intermolt period was also determined. The number of blood meals was quantified at each nymphal stage and the resistance to fasting as the period between ecdysis and death. Mortality was assessed and longevity was determined by recording the time that elapsed from molting to the adult stage and until death. The developmental cycle was assessed by recording the length in days of each stage from molting to adult hood. Results The average incubation period was 22.7 days. The average first meal occurred 3.1 days after hatching. The 5th stage nymph to adult intermolting period was the longest at 193.4 days. The average number of feedings during nymphal development was 13.4. The resistance to fasting assay indicated that the 3rd, 4th and 5th stage nymphs presented higher resistance than did adults. The highest mortality rate was observed in the 3rd stage nymphs (22.2%). The average length of adult survival was 25.6 weeks, and the average total life cycle lasted 503.4 days. Conclusions This study is the first report on the biology of T. carcavalloi that fed on mice. The presented findings expand the bionomic knowledge of these species.

Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909). The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934), and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female), fertility (eggs hatched/eggs laid), initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS), blood consumption index (CI), and E values (eggs/mg blood) were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

Detection of testicular cancer in men presenting with infertility

PURPOSE: Infertility is one of the less common presenting features associated with testicular tumors. We evaluated the histologic and biochemical findings, and pregnancy outcome in patients presenting with infertility who were found to have testicular tumors. METHODS: Seven patients with infertility were found to have testicular cancer over a 15-year period. All patients had a testicular ultrasound evaluation. The indications for the ultrasound were testicular pain in 2 patients, suspicious palpable mass in 4, and to rule out the presence of germ cell neoplasia in a patient with carcinoma in situ detected on a previous biopsy. Physical exam, histological findings, hormonal levels, tumor markers, and pregnancy outcome results were recorded from the patients medical charts. RESULTS: Two men had elevated serum follicle stimulant hormone and luteinizing hormone levels, 1 of them had an abnormally low serum testosterone level. Tumor markers were normal in all patients. In 4 patients the tumor was on the right side and in 3 on the left. The histological diagnoses were seminoma (n = 5), Leydig cell tumor (n = 1), and carcinoma in situ (n = 1). Of the 7 patients, 5 underwent adjuvant radiation therapy. Two patients had sperm cryopreserved. Follow up on fertility status was available in 6 cases. One patient has established a pregnancy and 5 did not achieve a pregnancy after treatment for their cancer. CONCLUSIONS: Most of the men who have testicular cancer and male infertility have a seminona. Therefore, men who present with infertility should be thoroughly investigated to rule out such serious, concomitant diseases along with their infertility.

Measuring male infertility: epidemiological aspects

Evidence suggests that human semen quality may have been deteriorating in recent years. Most of the evidence is retrospective, based on analysis of data sets collected for other purposes. Measures of male infertility are needed if we want to monitor the biological capacity for males to reproduce over time or between different populations. We also need these measures in analytical epidemiology if we want to identify risk indicators, risk factors, or even causes of an impaired male fecundity-that is, the male component in the biological ability to reproduce. The most direct evaluation of fecundity is to measure the time it takes to conceive. Since the time of conception may be missed in the case of an early abortion, time to get pregnant is often measured as the time it takes to obtain a conception that survives until a clinically recognized pregnancy or even a pregnancy that ends with a live born child occurs. A prolonged time required to produce pregnancy may therefore be due to a failure to conceive or a failure to maintain a pregnancy until clinical recognition. Studies that focus on quantitative changes in fecundity (that does not cause sterility) should in principle be possible in a pregnancy sample. The most important limitation in fertility studies is that the design requires equal persistency in trying to become pregnant and rather similar fertility desires and family planning methods in the groups to be compared. This design is probably achievable in exposure studies that make comparisons with reasonable comparable groups concerning social conditions and use of contraceptive methods.

Results of microsurgical anastomosis in men with seminal tract obstruction due to inguinal herniorrhaphy

The incidence of vasal injury during inguinal herniorrhaphy is estimated at 0.5%. We sought to assess the patency rates and long-term fertility outcome after microsurgical repair of vasal obstruction related to prior inguinal herniorrhaphy. METHODS: Twenty procedures were performed on 13 men diagnosed with infertility and vasal injury secondary to previous inguinal herniorrhaphy. Eight of these men had undergone bilateral and 5 unilateral inguinal herniorrhaphy. Twelve procedures were vasovasostomies, 3 were crossover vasovasostomies, 2 were vasoepididymostomies, and 3 were crossover vasoepididymostomies. Eight patients were azoospermic, 2 were severely oligospermic (<1 M/mL), 1 was oligospermic, and 2 were asthenospermic. Patency data was obtained on all 13 patients, and pregnancy data was available for 10 couples (77%), with a mean follow-up of 69.5 months. RESULTS: The overall patency rate was 65%. In the vasovasostomy group, the patency rate was 60% (9/15), and in the vasoepididymostomy group it was 80% (4/5). Among the azoospermic patients, 13 procedures were performed. The patency rate was 42.9% for the vasovasostomy (3/7), and 100% for the vasoepididymostomy procedure (4/4). The overall pregnancy rate was 40%. Of the men who underwent vasoepididymostomy, 80% (4/5) established a pregnancy. CONCLUSIONS: Microsurgical vasovasostomy after inguinal vas injury results in a reasonable patency rate but a lower pregnancy rate than that after vasectomy reversal. When microsurgical vasoepididymostomy was possible, it resulted in high patency and pregnancy rate. Crossover vasoepididymostomy, when appropriate, can be a useful alternative to inguinal vasovasostomy.

Finasteride-associated male infertility

Finasteride is a potent and specific inhibitor of the 5alpha-reductase enzyme in men. Clinical studies have shown that finasteride 1mg/day is effective for promoting hair growth in men with male pattern hair loss. However, there is a concern about the use of finasteride, especially in young fertile patients, because of its action on testosterone metabolism. This paper describes 3 cases of young patients who had very poor seminal quality during finasteride treatment (1 mg/day), and their seminal quality greatly improved after cessation of finasteride treatment. Two of them presented with a left varicocele and the other was obese. We hypothesize that finasteride may not dramatically change the spermatogenesis process in healthy men, but in patients with conditions related to infertility, an amplification of the negative influence of finasteride could occur. Future studies should be done to clarify the extent of the effect of finasteride in patients fertility problems.

The best infertility treatment for vasectomized men: assisted reproduction or vasectomy reversal?

In men with prior vasectomy, microsurgical reconstruction of the reproductive tract is more cost-effective than sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection if the obstructive interval is less than 15 years and no female fertility risk factors are present. If epididymal obstruction is detected or advanced female age is present, the decision to use either microsurgical reconstruction or sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection should be individualized. Sperm retrieval with in vitro fertilization and intracytoplasmic sperm injection is preferred to surgical treatment when female factors requiring in vitro fertilization are present or when the chance for success with sperm retrieval and intracytoplasmic sperm injection exceeds the chance for success with surgical treatment.

Effects of medical therapy, alcohol, smoking, and endocrine disruptors on male infertility

Infertility affects up to 15% of the sexually active population, and in 50% of cases, a male factor is involved, either as a primary problem or in combination with a problem in the female partner. Because many commonly encountered drugs and medications can have a detrimental effect on male fertility, the medical evaluation should include a discussion regarding the use of recreational and illicit drugs, medications, and other substances that may impair fertility. With the knowledge of which drugs and medications may be detrimental to fertility, it may be possible to modify medication regimens or convince a patient to modify habits to decrease adverse effects on fertility and improve the chances of achieving a successful pregnancy. Concern is growing that male sexual development and reproduction have changed for the worse over the past 30 to 50 years. Although some reports find no changes, others suggest that sperm counts appear to be decreasing and that the incidence of developmental abnormalities such as hypospadias and cryptorchidism appears to be increasing, as is the incidence of testicular cancer. These concerns center around the possibility that our environment is contaminated with chemicals - both natural and synthetic - that can interact with the endocrine system.

Observations on flower visitors to Bertholletia excelsa H.B.K. and Couratari tenuicarpa A.C. Sm. (Lecythidaceae)

Bees visiting flowers of Bertholletia excelsa. (Brazil Nut tree) and Couratari tenuicarpa were collected, their behavior described and the pollen found clinging to their dorsal thorax and stored on their legs was identified. Female bees of Xylocopa frontalis(Olivier) and males of Eulaema mocsaryi (Friese) are apparently effective pollinators of Couratari in igapó near Manaus. Female bees of Euplusia seabrai Moure in litt., Epicharis umbraculata (Fabricius), Epicharis rustica (Olivier) and Eulaema nigrita(Lepeletier), as well as male bees of Eulaema cingulata(Fabricius) and Eulaema nigrita are apparently effective pollinators of adult Brazil Nut trees in the Aleixo plantation near Manaus. Only large bees capable of uncurling the floral androecium can effectively pollinate Couratari or Bertholletia.Pollen analysis indicated that all bees captured carried pollen of the host tree in question and had been foraging on flowers of plant species common in secondary growth. Secondary growth near the Aleixo plantation supports a bee guild which appeared to effectively pollinate almost every flower on the Brazil Nut tree studied. Proximity to primary forest (and to those Euglossine bee species which occur only in primary forest) therefore does not appear to be necessary for pollination of Brazil Nut trees.In the Aleixo plantation chronic low fruit set is probably due to some factor other than pollination. Since natural occurrences of Brazil Nut trees to the north and south of Manaus are associated with a higher soil fertility, low production at the Aleixo plantation may be due to deficiencies of the soil.

Levels of leaf Herbivory in Amazonian trees from different stages In forest regeneration

Leaves from 120 canopy trees and 60 understory tree saplings growing in primary and secondary forests near Manaus, Brazil, were collected for determination of standing levels of herbivory (percent leaf area lost). Overall, levels of herbivory on leaves of central Amazonian trees were low. About one quarter of the leaves examined (n = 855) had no damage at all. In most other Neotropical sites studied the mean percentage of herbivory was found to vary between 5.7 and 13.1%, whereas in Manaus it was only 3.1%. The data presented here support the contention that levels of herbivore damage are positively related to soil fertility. No significant difference was found in herbivory levels between canopy trees and understory saplings. Also, there was no difference in damage between leaves from pioneer and late successional trees. Field assays of preference, however, revealed that leaves from pioneer trees are more palatable to leaf-cutting ants (Atta laevigata). This effect was dependent upon leaf age, being observed in mature leaves, but not in young leaves. The greater rate of leaf production in secondary forests may be a factor accounting for the greater abundance of leaf-cutting ants in secondary compared to primary forests.

Changes in population and land use over time in the Ecuadorian Amazon

This paper draws upon a detailed longitudinal survey of households living on agricultural plots in the northern three provinces of the Ecuadorian Amazon, the principal region of colonization by migrants in Ecuador since the 1970s. Following the discovery of petroleum in 1967 near what has subsequently come to be the provincial capital and largest Amazonian city of Lago Agrio, oil companies built roads to lay pipelines to extract and pump oil across the Andes for export. As a result, for the past 30 years over half of both Ecuador's export earnings and government revenues have come from petroleum extracted from this region. But the roads also facilitated massive spontaneous in-migration of families from origin areas in the Ecuadorian Sierra, characterized by minifundia and rural poverty. This paper is about those migrants and their effects on the Amazonian landscape. We discuss the data collection methodology and summarize key results on settler characteristics and changes in population, land use, land ownership, technology, labor allocation, and living conditions, as well as the relationships between changes in population and changes in land use over time. The population in the study region has been growing rapidly due to both natural population growth (high fertility) and in-migration. This has led to a dramatic process of subdivision and fragmentation of plots in the 1990's, which contrasts with the consolidation of plots that has occurred in most of the mature frontier areas of the Brazilian Amazon. This fragmentation has led to important changes in land tenure and land use, deforestation, cattle raising, labor allocation, and settler welfare.

Diversity of the land resources in the Amazonian State of Rondônia, Brazil

Conflicting opinions are recorded in the literature concerning the suitability of Amazon lands for sustainable agriculture following deforestation. This article has been written to shed light on this question by summarizing climate, landform, soil and vegetation features from the findings of a land resource study of the Brazilian state of Rondônia in south-west Amazonia. The work, which followed the World Soils and Terrain Digital Database (SOTER) methodology, was financed by the World Bank. During the course of the survey special emphasis was given to studying soils; 2914 profiles were analyzed and recorded. The study identified a complex pattern of land units with clear differences in climate, landform, soils and native vegetation. Forested areas mosaic with lesser areas of natural savannas. The latter occur on both poorly-drained and well-drained, albeit nutrient deficient sandy soils. The tallest and most vigorous forests or their remnants were seen growing on well-drained soils formed from nutrient-rich parent materials. Many of these soils could, or are being used for productive agriculture. Soils developed on nutrient-poor parent materials support forests that are significantly lower in height, and would require large lime and fertilizer inputs for agriculture. Low forests with high palm populations and minor areas of wet land savannas cover the poorly drained soils. It is evident that forest clearing in the past was indiscriminant; this cannot be condoned. The diversity of land conditions found throughout Rondônia would suggest that many past studies in the Amazon have simply been too broad to identify significant soil differences.

Environmental determinants for natural regeneration of gallery forest at the Cerrado/Amazonia boundaries in Brazil

Natural regeneration and structure and their relationship to environmental variables were studied in three sections of a gallery forest, in Eastern Mato Grosso, Brazil (14º43′S and 52º21′W). The assumption was that natural regeneration is constrained by environmental determinants at all stages of development of the tree community. The objective was to analyse the forest structure and to verify the relationship between species distribution and abundance at different stages of regeneration and environmental variables. In each section, 47 contiguous (10x10m) permanent plots were established to sample trees (gbh≥15cm), following a systematic design. Seedlings (0.01 to 1m height), saplings (1.01 to 2m) and poles (from 2.01m height to gbh<15cm) were sampled in sub-plots of 1x1m, 2x2m and 5x5m, respectively. In each plot, soil properties, gaps projection, bamboos, rocky cover, declivity and depth of ground watertable were determined. The relationships between the environmental variables with trees and seedling communities were assessed by canonical correspondence analysis. In spite of the sections being near to each other, they presented large differences in floristics, structure and site conditions. The forest soil presented a low cation exchange capacity and a high level of Al saturation. The occurrence of bamboos and gaps and the depth of ground watertable limited the occurrence of poles and trees. The high degree of structural heterogeneity for each regeneration category was related primarily to a humidity gradient; but soil fertility (Ca+Mg) was also a determinant of seedling and sapling communities.