The immune response and fertility of koalas (Phascolarctos cinereus) immunised with porcine zonae pellucidae or recombinant brushtail possum ZP3 protein

To evaluate the potential contraceptive effect of immunisation with zona pellucida antigens, 50 free-ranging koalas were immunised with either porcine zonae pellucidae (PZP), recombinant brushtail possum ZP3 (recBP-ZP3) or buffer, in complete Freund's adjuvant. A single booster immunisation in incomplete Freund's adjuvant was administered 3–5 months later. Where possible animals were recaptured, reproductive status was assessed and blood was collected at 1–3-month intervals for the next 33 months. Forty-three koalas were recaptured at least three times allowing reliable assessments of their fertility. Fourteen animals were observed never to have a pouch young. Of the remaining 29 animals the reproductive productivity of PZP treated females was reduced compared with control and recBP-ZP3 treated females, in terms of both total number of young produced, and failure to produce further young in females of proven fertility. One month after the initial immunisation, serum antigen-specific antibody titres were higher in animals immunised with PZP or recBP-ZP3 compared to controls, and reached a plateau by 4 months. Antibody against the relevant immunising antigen was also detected in ovarian follicular fluid, uterine fluid and vaginal secretions. Epitope analysis suggested that immune responses other than antibodies directed against the ZP3 amino acid sequence were responsible for mediating infertility. The results demonstrate that the fertility of female koalas can be compromised by immunisation against zona pellucida antigens. However, unlike in the eastern grey kangaroo and the brushtail possum, immunisation with bacterial recombinant brushtail possum ZP3 did not compromise fertility in the koala.     

Attitudes towards prenatal HIV testing and treatment among pregnant women in southern India

During June and July 1999, oral interviews were conducted on 666 women seeking prenatal care at 9 medical facilities in Chennai and Mysore, India, to assess their attitudes towards prenatal HIV testing and antiretroviral prophylaxis for preventing perinatal HIV transmission if needed. Seventy-eight per cent were aware of the risk of perinatal HIV transmission and 36% knew that intervention could reduce the chances of such transmission. Eighty-six per cent would agree to undergo prenatal HIV testing but only 21% of all respondents would make this decision independently while 46% said their husband would have to decide. Of those women who would not agree to testing, 21% would agree if testing were compulsory. Ninety-seven per cent of respondents would undergo antiretroviral prophylaxis to prevent vertical transmission, and 94% would consider alternatives to breastfeeding if HIV positive. Considering its widespread acceptability, prenatal voluntary counselling and testing may be an affordable method of HIV prevention for this population.     

Metabolic studies on the possible mode of action of isoniazid tumorigenicity

Summary Data on tumorigenicity and mutagenicity of INH show that INH is tumorigenic in mice but not in rats. The metabolic studies on the two species denote that rats are rapid inactivators whereas mice are slow inactivators of INH. Rats are also resistant to the immediate inhibitory effect of INH on DNA biosynthesis. Using Ames test it was observed that INH is mutagenic to salmonella typhimurium strains TA 100 and 1535 and this effect is abolished in presence of 59 mixture. In vivo and in vitro studies on INH interaction with macromolecules reveal that there is a greater interaction with RNA than with DNA and the site of interaction is the cytidine and deoxycytidine, respectively. A preliminary study is undertaken to see if healed TB cases have a higher risk for cancer. It is found that cancer incidence in this group is higher as compared to noncancer patients.     

Vectorcardiograms in severe aortic insufficiency. Clockwise rotation of QRS loop in the horizontal plane.

In La Paz Hospital, Madrid, recently, vectorcardiograms (VCGs) were performed on 74 patients with aortic insufficiency. These cases presenting electrocardiographic and radiologic signs of left ventricular hypertrophy, were divided into three groups. In 25 patients (Group 1) the QRS loop in the horizontal plane (HP) showed counterclockwise rotation; 43 patients (Group 2) showed clockwise rotation; and 6 patients (Group 3) showed a pattern of left bundle branch block (LBBB). In Group 2, 31 of the 43 patients (group 2-A) had a Qloop of normal orientation and generally increased voltage, and in the remaining 12 patients (group 2-B) the Q loop was absent. All of the patients in Group 2 had severe aortic insufficiency. Thus, that group's valuation of the left ventricular hypertrophy using maximum QRS vector voltage in the HP, was higher than in Group 1 mean 3.75mV in Group 2 versus mean 2.71mV in Group 1 (p less than 0.01). Postoperative VCGs were performed in 12 patients of group 2-A, showing in all of them a clockwise to counterclockwise rotation change of the QRS loop in the HP. On the other hand, this fact was observed in only two of the eight patients in group 2-B. The clockwise rotation of the QRS loop in the HP is an important datum in our report, particularly in the diagnosis of severe aortic insufficiency. Conversely, a clockwise to counterclockwise rotation change would be a positive sign of good post operative evolution. Finally, two reasons are given to explain this anomalous rotation in the horizontal plane: dilatation and fibrosis.     

In Vivo Sugar Diffusion in the Ileal Epithelium of Spontaneously Hypertensive Rats

Background: D -glucose absorption, distinguishing between active and diffusive components, was studied in the ileum of spontaneously hypertensive rats (SHR) and their normotensive control Wistar-Kyoto (WKY) rats. Net water transport was also determined. Methods: A perfusion system in vivo with ileum loops was used, and experiments with phlorizin, phloretin and 2,4,6-triaminopyrimidine (TAP) were performed in order to discriminate between active and diffusive components and between transcellular and paracellular routes. Results: A significant decrease in total D -glucose absorption was found in SHR compared to WKY rats, this reduction being due to a lower SGLT1-mediated component. The effect was not compensated by the total diffusive component, since the phlorizin-insensitive D -glucose absorption did not significantly change between rat strains. However, the diffusive component of D -glucose transport was relatively more important in hypertensive than in normotensive rats. The use of 2,4,6-triaminopyrimidine (TAP), which blocks the transport across the paracellular route, showed that the paracellular diffusion of D -glucose was higher in SHR than in WKY rats. Intestinal net water absorption was not modified between either group of animals, though the presence of phlorizin in the perfusate decreased the ileal water absorption to a greater extent in normotensive rats. Conclusion: The observed reduction in D -glucose absorption in vivo in the ileum of SHR was due to a decrease in the SGLT1-active component. Despite the paracellular diffusion of D -glucose being higher in hypertensive than in normotensive rats, the total diffusion component was not high enough to compensate this alteration.     

Brain-derived neurotrophic factor (BDNF) overexpression in the forebrain results in learning and memory impairments

In this study we analyzed the effect on behavior of a chronic exposure to brain-derived neurotrophic factor (BDNF), by analysing a mouse line overexpressing BDNF under the αCaMKII promoter, which drives the transgene expression exclusively to principal neurons of the forebrain. BDNF transgenic mice and their WT littermates were examined with a battery of behavioral tests, in order to evaluate motor coordination, learning, short and long-term memory formation. Our results demonstrate that chronic BDNF overexpression in the central nervous system (CNS) causes learning deficits and short-term memory impairments, both in spatial and instrumental learning tasks. This observation suggests that a widespread increase in BDNF in forebrain networks may result in adverse effects on learning and memory formation.     

Protection of Chinese painted quails (Coturnix chinensis) against a highly pathogenic H5N1 avian influenza virus strain after vaccination

Chinese painted quails immunized with a single dose (6 μg HA) of inactivated H5N1 (clade 1) influenza vaccine NIBRG-14 and challenged with 100 LD₅₀ of the heterologous A/Swan/Nagybaracska/01/06(H5N1) (clade 2.2) strain were protected, whereas unvaccinated quails died after challenge. No viral antigens or RNA were detected in cloacal swabs from immunized animals. Sera obtained post-immunization gave low titres in serological assays against the vaccine and the challenge viruses. Our results demonstrate the protective efficacy of the NIBRG-14 strain against the challenge virus and the usefulness of these small birds in protection studies of influenza vaccines.