The reproductive performance of sows after PRRS vaccination depends on stage of gestation

In order to minimize the effects of porcine reproductive and respiratory syndrome (PRRS) on stillbirth, mummification, and neonatal mortality in swine herds, many producers have vaccinated their herds using a modified-live virus vaccine. The purpose of this study was to determine the association of the PRRS modified-live vaccine and reproductive performance by stage of gestation when the vaccine was administered. A total of 47 swine herds from Ontario and Manitoba, Canada, and from the mid-western USA were included in the study. Participating farms had vaccinated all of their sows at one point in time when they used the vaccine for the first time. The reproductive performance of sows that farrowed in the year prior to use of the vaccine was compared to that of sows vaccinated in each of five stages of gestation and in the gestation that followed the initial use of the vaccine. Sows vaccinated at any time during gestation had a reduced number of pigs born alive, a reduced number of pigs weaned per litter, and increased number of stillborn pigs and an increased number of mummified pigs compared to the sows that farrowed prior to use of the vaccine. The largest association was seen in sows that were vaccinated in the last four weeks of gestation. The largest losses were observed in those herds that were vaccinated concurrently with the initial PRRS herd outbreak. These results suggest that the modified-live vaccine should only be administered to non-gestating sows.

Mucosal inflammation in severe glucocorticoid-dependent asthma

To improve our understanding of the inflammatory mechanisms underlying severe disease, a biopsy study was performed comparing 15 clinically unstable glucocorticoid-dependent asthmatics, 10 mild asthmatics, and 10 control subjects. Compared with mild asthma, severe asthma was characterized by reduced mucosal eosinophilia. Whilst no significant differences were found in the numbers of mast cells, neutrophils, CD3+ and CD4+ T-cells between the three groups, up to a 4-fold increase In the numbers of activated T-lymphocytes bearing the interleukin (IL)-2 receptor (IL-2R) was found in the mucosa in severe asthma compared to mild asthma (p = 0.03) and control subjects (p = 0.003). Compared to control subjects, the mucosa of severe asthmatics contained significantly (p = 0.02) higher numbers of IL-5+ cells, with no differences between mild and severe disease. In contrast, staining for the anti-IL-4 monoclonal antibody 3H4 revealed that biopsies from mild asthmatics contained more IL4+ cells than biopsies from severe asthmatics and control subjects (p = 0.0008). In the severe asthmatics, a close correlation (r(s) = 0.76, p = 0.005) was found between the numbers of IL-2R-bearing cells and the variability in peak expiratory flow. In conclusion, persistent T-cell activation is a prominent feature of severe asthma. These results also indicate that interleukin-5, and not interleukin-4, is upregulated in severe disease.

Oral vaccination of mice with human papillomavirus virus-like particles induces systemic virus-neutralizing antibodies

To assess whether oral vaccination against human papillomavirus (HPV) may be feasible, we administered HPV virus-like particles (VLPs) to mice by gavage. Enzyme-linked immunosorbent assay (ELISA) results indicated that serum anti-VLP immunoglobulin G (IgG) and IgA antibodies were induced after oral vaccination, and these responses demonstrated antigenic specificities that were conformationally dependent and restricted according to HPV genotype. Importantly, orally induced postimmune sera were found to neutralize HPV-11 virions in vitro. These results indicated that the VLPs were antigenically stable in the environment of the gastrointestinal tract and were able to engage in potentially useful immune system interactions. These findings support the concept of oral vaccination against anogenital HPV disease, and suggest the possibility that this may be a useful approach to the immunization of large populations against cervical cancer and other HPV associated diseases.

Gadolinium chloride toxicity in the mouse

1. Groups of five male and five female CD-1 mice received a single intravenous injection of gadolinium chloride at dosages of 0 (saline control), 0.05, 0.1 and 0.2 mmol/ kg. All mice were necropsied 48 h post dose. 2. Plasma analysis showed increases in concentrations of lactate dehydrogenase (both sexes), aspartate aminotransferase and alanine aminotransferase (females only) in the 0.2 mmol/kg group. Cholesterol was elevated at all dosages in both sexes whilst globulin was raised in both sexes at 0.1 and 0.2 mmol/kg. 3. Histological lesions were present at all dosages and increased in severity in a dose-related fashion. The most common lesions were: mineral emboli in capillaries, accumulation of mineral in the mononuclear phagocytic system, hepatocellular necrosis, and lymphoid depletion, necrosis and mineralisation in the spleen. 4. Such observations are similar to those in rats given gadolinium chloride and should be assessed when evaluating the toxicological profile of gadolinium containing compounds being developed for nuclear magnetic resonance imaging.

Comparison of physical chemical properties of llama VHH antibody fragments and mouse monoclonal antibodies

Antigen specific llama VHH antibody fragments were compared to antigen specific mouse monoclonal antibodies with respect to specificity, affinity and stability. The llama VHH antibody fragments and the mouse monoclonal antibodies investigated were shown to be highly specific for the protein antigen hCG or the hapten antigen RR-6. The affinity of the interaction between monovalent llama VHH antibody fragments and their antigen is close to the nanomolar range, similar to the bivalent mouse monoclonal antibodies studied. Llama VHH antibody fragments are similar to mouse monoclonal antibodies with respect to antigen binding in the presence of ammonium thiocyanate and ethanol. The results show that relative to antigen specific mouse monoclonal antibodies, antigen specific llama VHH fragments are extremely temperature stable. Two out of six llama VHHs are able to bind antigen specifically at temperatures as high as 90 degrees C, whereas four out of four mouse monoclonal antibodies are not functional at this temperature. Together with the finding that llama VHH fragments can be produced at high yield in Saccharomyces cerevisiae, these findings indicate that in the near future antigen specific llama VHH fragments can be used in for antibodies unexpected products and processes.

Advanced practice nursing: opportunities and challenges

Planning for the future may not be easy but it is always worthwhile. Resources that can help in making choices include professional organizations such as the Kentucky Coalition of Nurse Practitioners and Nurse Midwives, KNA, American Academy of Nurse Practitioners, American College of Nurse Practitioners, the Internet, and the college and university Schools of Nursing. Taking control of one's destiny is the best gift that can be given to one's self. Increasing options for career development is just one of the benefits of pursuing educational goals. The first step is commitment to goal. Selecting the right specialty, planning how financial obligations will be met and choosing the program that best meets identified needs are steps that will follow. Health care changes are occurring at such a rapid pace the individual nurse may feel caught in a whirlwind without control. Making the choice to seek change will present its own challenges but without change, growth is impossible. For those considering an Advanced Practice role, making the commitment, outlining a plan with each step clearly identified, reliance on a strong support system, and maintaining a vision of the completed goal will lead to success.

Anesthesia for pediatric dentistry

The administration of anesthesia to young patients creates a unique series of problems for the anesthesiologist. This article details these various problems and tackles the primary challenge facing clinicians in this environment: providing an environment that allows technically complex dental treatment to be delivered without inflicting any adverse psychological impact on the child or physical harm to the child or others.

Recent advances in 7-transmembrane receptor research

Approximately half of the currently known drugs act on cell surface receptors, the majority of which are 7-transmembrane (7-TM) receptors. The advent of genomic technologies has provided drug discovery scientists with a plethora of fascinating challenges, in particular a large increase in the number of potential 7-TM receptor targets for which the biological role, ligands and assays need to be found. These technologies have also led to novel and puzzling insights into the complex world of structure and function. Recent advances in the identification, classification, structure and function of 7-TM receptors are reviewed, together with the latest assay methods and the identification of novel ligands.

Phase I study of combination therapy with intravenous cidofovir and oral ganciclovir for cytomegalovirus retinitis in patients with AIDS

Ganciclovir and cidofovir, two antiviral agents used in the treatment of cytomegalovirus (CMV) retinitis, have a synergistic effect inhibiting CMV replication in vitro. In a phase I study, seven patients with AIDS-related CMV retinitis were treated with cidofovir (5 mg/kg intravenously every 2 weeks) combined with ganciclovir (1 g orally three times a day). During a median of 5.5 months (range, 1-12 months) of combined therapy, only one patient had retinitis progression, and only two of 28 blood cultures (specimens of which were obtained on a monthly basis) yielded CMV. Dose-limiting adverse ocular effects (anterior uveitis [two patients] and hypotony [two patients]) occurred in three of seven patients. The results suggest that combination therapy with intravenous cidofovir and oral ganciclovir (a regimen that does not require indwelling central venous catheter access) might enhance clinical efficacy. Less frequent administration of cidofovir in combination with oral ganciclovir should be prospectively studied to determine if the incidence of treatment-associated toxicity might be reduced.

Is default from colposcopy a problem, and if so what can we do? A systematic review of the literature

It has been reported that many women referred to outpatient colposcopy clinics fail to attend for their appointments. The aim of this paper is to search the literature to assess the extent of default from colposcopy and to identify interventions, suitable for implementation within primary care, to reduce the proportion of women defaulting. Searches were performed on MEDLINE, PsychLIT, Bids and Cancerlit from 1986 to September 1997 using the terms colposcopy or cervical/Pap smear in association with default, non-attendance, adherence, patient compliance, treatment refusal, patient dropouts, attendance, barriers or intervention. The inclusion criteria for primary papers were that they contained data that enables the calculation of default rates for colposcopy or the results of interventions aimed at improving the default rates. Thirteen publications describing default rates and four describing interventions were included as primary papers. Combining the data from these studies suggests default rates of 3%, 11%, and 12% for assessment/treatment visits, first review, and second review respectively. The intervention studies suggested a need to tailor the intervention to the population and the type of information to suit the individual. Varying definitions make comparison of default rates difficult, and the use of a crude non-attendance rate may result in an overestimate of default rates. The vast majority of women invited to colposcopy eventually attend. It is questionable if there is a need for interventions to increase compliance. Where necessary, greater cooperation across the primary/secondary care interface and use of the extended primary care team may be a more cost-effective means of increasing compliance.