On the Adult Behavioral Repertoire of the Sawfly Perreyia flavipes Konow, 1899 (Hymenoptera: Pergidae): Movement, Mating, and Thanatosis.

Perreyia flavipes Konow, 1899 (Pergidae: Perreyinae) is a sawfly species with gregarious larvae commonly found in open areas in southern Brazil through Uruguay and northern Argentina. The combination of highly gregarious larvae with the production of a variety of toxins in P. flavipes has led to severe cases of intoxication in a variety of livestock species. Over the years, considerable information was discovered on the larval natural history of P. flavipes; however, virtually nothing is known about the adult behavior, particularly because of its short life-span. In this study, we report on the first extensive study on the adult behavior of P. flavipes, including movement, mating (with oviposition and maternal care), and thanatosis. Our results show some unusual behavioral adaptations presented by P. flavipes, such as irregular activity behavior (i.e., deficient gait pattern), thanatosis behavior-like display, and primitive maternal care. Individual behavioral acts are described and compared among sexes, and their potential functions are discussed.

Late reproductive analysis in rat male offspring exposed to nicotine during pregnancy and lactation.

We previously observed that nicotine, administered to rats (Wistar) during pregnancy and lactation periods, provokes, in the progeny, late morphofunctional alterations in Leydig cell, body weight increase in adulthood (90 days post partum, dpp) as well as seminiferous epithelium injury. Aiming to investigate whether the spermatogenic damage previously observed in adult progenies from pregnant and lactating nicotine-exposed rat dams are maintained or whether it is worsened in older rats, we analyzed the morphological testicular alterations after up to two complete periods of spermatogenesis (53 days each), spermatic parameters, and sperm DNA fragmentation. Pregnant and lactating rats were nicotine-exposed (2 mg/kg/day) through an osmotic minipump implanted on the first day of pregnancy and replaced after birth. Absolute Control (no minipump) and Sham Control (minipump without nicotine) groups were established. The offspring were killed at 90, 143, and 196 dpp. Significant alterations in morphometric and stereological testicular parameters, such as concentration of sperm number, daily sperm production, and plasma and intratesticular levels of cholesterol and testosterone were not observed in nicotine-exposed rats. Testicular histopathological analysis showed small intraepithelial vacuolization and an accentuated germ cell desquamation in exposed rats. However, the offspring from nicotine-exposed dams exhibited higher frequency of morphologically abnormal spermatozoa and lower sperm motility in comparison with control groups. In addition, nicotine-exposed groups showed a significant reduction in sperm mitochondrial activity and an increased sperm DNA fragmentation (Comet assay). These results indicate a late reproductive damage in the male progeny caused by maternal nicotine exposure, related to the decrease in sperm quality.

Effects of prenatal and lactation nicotine exposure on rat testicular interstitial tissue.

Nicotine is largely consumed as a component of cigarettes. It induces apoptosis, interferes with endocrine function by changing the sex hormones secretion and leads to male infertility. Testosterone is produced from cholesterol by Leydig cells (LC), with the participation of testicular macrophages (MO). Thus, to investigate whether nicotine administration to pregnant and lactating rats changes cholesterol and sexual hormone levels and LC and MO populations of offspring, female rats received nicotine (2 mg/kg/day) through osmotic minipumps from the first day of pregnancy up to the end of weaning. At 1, 30, 60 and 90 days post-partum (dpp) the plasma cholesterol and testosterone levels were obtained, as well as the biometric, histopathological and stereological testicular parameters. Nicotine reduced the body weight, cholesterol levels and lipid droplet number in foetal LC at 1 dpp. The number of apoptotic LC did not change in the offspring of nicotine group at any age studied. No alterations in the numerical densities of MO and LC occurred at 60 and 90 dpp. Hypertrophy of mature LC and increase in cholesterol and testosterone levels were noted at 90 dpp. In conclusion, nicotine when administered to rats throughout pregnancy and lactation induces morphofunctional alterations of foetal and mature LC and affects cholesterol and testosterone levels.

Molecular characterization of methicillin-resistant Staphylococcus aureus disseminated in a home care system.

OBJECTIVE: To study colonization with methicillin-resistant Staphylococcus aureus in a home care service during a 4-month period. DESIGN: Prospective study. SETTING: A home care service located in Rio de Janeiro, Brazil. PARTICIPANTS: Patients admitted to the home care service during this period, their household contacts, and health care workers (HCWs). METHODS: Swab specimens from the anterior nares were collected from each patient in the 3 groups at admission. Screening was repeated every 7 days. MRSA was detected using a mecA probe, and the clonality of isolates was evaluated by molecular methods, primarily pulsed-field gel electrophoresis. RESULTS: Of the 59 study patients, 9 (15.3%) had MRSA colonization detected; these cases of colonization were classified as imported. Only 1 (2.0%) of the 50 patients not colonized at admission became an MRSA carrier (this case of colonization was classified as autochthonous). Two (0.9%) of 224 household contacts and 16 (7.4%) of 217 HCWs had MRSA colonization. Cross-transmission from patient to HCW could be clearly demonstrated in 8 cases. The great majority of MRSA isolates belonged to the Brazilian epidemic clone. CONCLUSIONS: MRSA colonization was common in the home care service analyzed. The fact that the majority of MRSA isolates obtained were primarily of nosocomial origin (and belonged to the so-called Brazilian epidemic clone) substantiated our findings that all but 1 patient had already been colonized before admission to the home care service. Only cross-transmission from patients to healthcare workers could be verified. On the basis of these results, we believe that a control program built on admission screening of patients for detection of MRSA carriage could contribute to the overall quality of care.