Adenosine 3',5'-cyclic phosphate: stimulation of steroidogenesis in sonically disrupted adrenal mitochondria.

Adenosine 3'5'-cyclic phosphate stimulated the conversion of added cholesterol to pregnenolone in "coupled" rat adrenal mitochondria provided with succinate, and in "leaky" mitochondria fortified with reduced nicotinamide adenine dinucleotide phosphate. Adenine nucleotides other than adenosine 3',5'-cyclic phosphate did not duplicate these actions. The cyclic nucleotide was also effective in supernatants from sonically disrupted mitochondria. The minimum effective concentration was 50 micromoles per liter or less. The results suggest that adenosine 3',5'-cyclic phosphate stimulates corticosteroidogenesis by activating the mitochondrial enzymes which are rate-limiting in the utilization of cholesterol.

Assessment of plasminogen synthesis in vitro by mouse tumor cells using a competition radioimmunoassay for mouse plasminogen.

A sensitive, specific competition radioimmunoassay for mouse plasmin(ogen) has been developed in order to determine whether mouse tumor cells can synthesize plasminogen in vitro. The rabbit anti-BALB/c mouse plasminogen antibodies used in the assay react with the plasminogen present in serum from BALB/c, C3H, AKR and C57BL/6 mice, and also recognized mouse plasmin. The competition radioimmunoassay can detect as little as 50 ng of mouse plasminogen. No competition was observed with preparations of fetal calf, human and rabbit plasminogens. A variety of virus-transformed and mouse tumor cell lines were all found to contain less than 100 ng mouse plasminogen/mg of cell extract protein. Thus, if the plasminogen activator/plasmin system is important in the growth or movement of this group of tumor cells, the cells will be dependent upon the circulatory system of the host for their plasminogen supply.

Recombinant fowlpox virus vaccines against Australian virulent Marek's disease virus: gene sequence analysis and comparison of vaccine efficacy in specific pathogen free and production chickens.

We have cloned and sequenced the glycoprotein genes gB, gC and gD of the Australian virulent Marek's disease virus (MDV) isolate Woodlands No. 1. The glycoprotein gB and gC sequences were identical to the homologs of other virulent MDV type 1 strains, and the glycoprotein gD sequence contained only one unique amino acid substitution. Recombinant fowlpox viruses (rFPVs) expressing the MDV glycoprotein genes were constructed and their efficacy as vaccines was evaluated in specific pathogen free (SPF) and production chickens. Vaccination with the FPV-gB recombinant protected SPF chickens from Marek's disease mortality and tumour formation following challenge with virulent MDV Woodlands No. 1. The degree of protection from Marek's disease was dependent on the vaccine dose and route of inoculation. The rFPVs expressing gC or gD did not provide protection from Marek's disease. A rFPV expressing both gB and gC did not provide enhanced protection in comparison with the rFPV-gB alone. The rFPV-gB vaccine failed to protect commercial chickens from MD mortality and provided little protection from tumour formation in comparison with the commercial herpesvirus of turkey (HVT) vaccine. The failure to provide protection against MD may be related to the impact of maternally derived immunity to MDV and FPV and possibly the genotype of the chickens.

National trends in the management of tubal pregnancy, 1970-1987.

Tubal pregnancy leads to reduced childbearing potential and is a major cause of maternal morbidity and mortality in the United States. Several hospital-based studies have shown a trend toward more conservative management of tubal pregnancies, which reflects attempts to reduce morbidity and preserve fertility; however, the impact on future fertility remains unclear. To study national trends in the management of tubal pregnancy from 1970-1987, we analyzed data from the National Hospital Discharge Survey. Tubal pregnancies managed conservatively, using operative procedures that attempt to preserve the function of the involved fallopian tube, increased from approximately 2% in 1970-1978 to 12% in 1984-1987. During 1979-1987, conservative procedures were more than twice as common for women with private insurance as for those without it. The use of diagnostic laparoscopy increased from 10% of tubal pregnancies in 1970-1978 to 33% in 1979-1987, whereas the use of diagnostic laparotomy decreased from 24 to 2%.

Influence of vaccine deposition site on post-vaccinal viraemia and vaccine efficacy in broiler chickens following in ovo vaccination against Marek's disease.

In ovo vaccination against Marek's disease is a widely used technology in the broiler industry.A series of experiments was carried out to determine the site of vaccine deposition in the egg during automated in ovo vaccination, and the effect of vaccine deposition site and dose on vaccine responses following vaccination with cell-associated herpesvirus of turkeys in commercial broiler chickens. Vaccine deposition site following automated in ovo vaccination was principally influenced by the age of embryo, with egg size having a smaller effect. The frequency of vaccine deposition inside the embryo body increased as incubation progressed from day 17.5 to 19.5. In experiments using manual vaccine deposition intra-embryonically (IE) or extra-embryonically (EE) at day 18.5, EE vaccine deposition resulted in a significantly delayed development of post-vaccinal viraemia relative to both IE vaccination and subcutaneous vaccination at hatch. There were no effects of vaccine dose (2000, 4000 or 8000 plaque forming units) on the timing of post-vaccinal viraemia. The timing of post-vaccinal viraemia was found to be a good indicator of the level of protection provided by the vaccine against challenge with earlier viraemia associated with better protection. IE vaccine deposition induced significantly greater protection than EE deposition against challenge with a virulent strain of Marek's disease virus. IE deposition consistently produced a high level of protection (68 to 84%) irrespective of vaccine dose or challenge day, while EE vaccine deposition produced no or low levels of protection (0 to 27%) depending on the vaccine dose and day of challenge. The growth of challenged chickens was also affected by site of vaccine deposition, with significantly higher live weights at day 56 of age in IE compared with EE vaccinated groups. These data suggest that the site of vaccine deposition within the embryo is an important determinant of the success of in ovo vaccination.

Transmission of virus from serosal fluids and demonstration of antigen in neutrophils and mesothelial cells of cattle infected with bovine ephemeral fever virus.

Following intravenous injection of bovine ephemeral fever (BEF) virus 6 cattle were autopsied after clinical disease became evident. Fluid from serosal cavities with serofibrinous inflammatory changes showed large increases in neutrophil numbers. BEF virus was detected for the first time in pericardial, thoracic and abdominal fluids. Virus was also detected in synovial fluids, confirming an earlier report of transmission with a synovial fluid sample. Using a direct fluorescent antibody technique, BEF virus antigen was identified for the first time in synovial, pericardial, thoracic and abdominal fluids, in synovial membranes and epicardium. In synovial membranes and epicardium, specific fluorescence was observed in two cell types, mesothelial cells and neutrophils. In the fluids, fluorescence was restricted to neutrophils, the predominant cell type. Specific fluorescence was observed in blood smears from only one animal although blood samples collected at autopsy from all animals contained infective virus.

Genetically altered herpesviruses as vaccines.

Herpesviruses are a common and important cause of disease in most domestic animals. While many virus diseases have been successfully controlled by conventional vaccines, genetically modified vaccines offer distinct advantages. They are less virulent, less likely to result in latency and they include genotypic and phenotypic markers which allow differentiation of vaccine virus from wild-type virus and serological differentiation of vaccinated animals from infected animals. These benefits are particularly useful in eradication campaigns for herpesvirus diseases such as Aujeszky's disease and infectious bovine rhinotracheitis. Neither conventional nor genetically modified vaccines prevent super-infection. This is a major problem for diseases such as Marek's disease where virulent virus continues to be excreted from vaccinated animals, thus contaminating the environment and making control more difficult. To prevent infection, new strategies will need to be developed such as transgenic animals which are innately resistant.

Newly discovered viruses of flying foxes.

Flying foxes have been the focus of research into three newly described viruses from the order Mononegavirales, namely Hendra virus (HeV), Menangle virus and Australian Bat Lyssavirus (ABL). Early investigations indicate that flying foxes are the reservoir host for these viruses. In 1994, two outbreaks of a new zoonotic disease affecting horses and humans occurred in Queensland. The virus which was found to be responsible was called equine morbillivirus (EMV) and has since been renamed HeV. Investigation into the reservoir of HeV has produced evidence that antibodies capable of neutralising HeV have only been detected in flying foxes. Over 20% of flying foxes in eastern Australia have been identified as being seropositive. Additionally six species of flying foxes in Papua New Guinea have tested positive for antibodies to HeV. In 1996 a virus from the family Paramyxoviridae was isolated from the uterine fluid of a female flying fox. Sequencing of 10000 of the 18000 base pairs (bp) has shown that the sequence is identical to the HeV sequence. As part of investigations into HeV, a virus was isolated from a juvenile flying fox which presented with neurological signs in 1996. This virus was characterised as belonging to the family Rhabdoviridae, and was named ABL. Since then four flying fox species and one insectivorous species have tested positive for ABL. The third virus to be detected in flying foxes is Menangle virus, belonging to the family Paramyxoviridae. This virus was responsible for a zoonotic disease affecting pigs and humans in New South Wales in 1997. Antibodies capable of neutralising Menangle virus, were detected in flying foxes.

Antibodies against certain bluetongue and epizootic haemorrhagic disease viral serotypes in Indonesian ruminants.

The orbiviruses contain several important viruses of livestock including bluetongue (BT) and epizootic haemorrhagic disease of deer (EHD) which share some group antigens. Preliminary screening of sera for antibodies to orbiviruses by the agar gel immunodiffusion (AGID) test has previously revealed widespread infections with the BT group in Indonesia. However serum neutralization (SN) tests give a more accurate estimate of exposure to each serotype in the BT and EHD groups, and in this study were applied to sera that had reacted previously in the AGID test. Five different serotypes of BT and one serotype of EHD virus were studied. Reactors to BT serotype 20 were the most prevalent, followed by EHD type 5 and BT types 21, 12, 1 and 17. Antibodies against BT serotype 20 were present in cattle, buffaloes, goats and sheep, but were most common in buffaloes. Buffaloes showed the highest exposure to the BT serotypes tested. Antibody to EHD type 5 occurred most frequently in cattle. Antibodies against all BT and EHD serotypes tested were found in buffaloes and cattle while goats had antibodies against BT types 20, 21 and EHD type 5 and sheep had antibodies only against BT type 20.

Reactivation of a macropodid herpesvirus from the eastern grey kangaroo (Macropus giganteus) following corticosteroid treatment.

The family Herpesviridae is a large group of viruses which contain double stranded DNA genomes. Biological characteristics, such as host signs, site of replication and site of latency have been used to describe three major subfamilies, Alphaherpesvirinae, Betaherpesvirinae and Gammaherpesvirinae within the family Herpesviridae. Macropodid herpesviruses (MaHV) have been implicated in fatal outbreaks amongst the captive marsupial populations of Australia. These outbreaks have resulted in the isolation of nine MaHV strains which have been classified into two species called macropodid herpesvirus 1 and 2 (MaHV-1 and MaHV-2). Biological characteristics have been used to place MaHV-1 and -2 within the subfamily Alphaherpesvirinae. Molecular phylogenetic reconstructions indicate an unusual position for MaHV-1 and -2 within the alphaherpesviruses. Current isolates of MaHVs have all been obtained from marsupials exhibiting clinical disease. A common biological characteristic of herpesviruses is the establishment of latent infections in nervous tissue. We have determined that MaHV are able to latently infect eastern grey kangaroos through reactivating and isolating a herpesvirus by inducing immunosuppression. We have investigated the possible sites of latency for MaHV-1 using molecular techniques. Detection of herpesvirus DNA in the trigeminal ganglia taken from two naturally infected eastern grey kangaroos indicates dissemination via a respiratory route.

The pathogenesis of velogenic Newcastle disease virus infection of chickens of different ages and different levels of immunity.

Chickens of 7 weeks or 20 weeks of age were divided into three groups according to their antibody status (high, low, absent) and were infected with a velogenic viscerotropic Newcastle disease virus. To follow patterns of viral replication, birds were necropsied at regular intervals up to 22 days and organs were sampled from each bird. In non-immune birds, virus could be isolated from all organs examined. In birds with antibody, virus was most frequently isolated from the proventriculus, cecal tonsil, bursa, and brain. However, because no one organ could be recommended for all situations, all four should be sampled for field diagnosis. In immune birds, although clinical signs were either mild or absent, widespread virus replication occurred up to 19 days post-challenge.

Demonstration of vascular permeability changes in cattle infected with bovine ephemeral fever virus.

Five cattle infected with bovine ephemeral fever virus were necropsied on the day after onset of clinical disease, when clinical signs of lameness were most severe. Gross lesions observed included a serofibrinous polyserositis involving the synovial, pericardial, thoracic and abdominal cavities. The associated histological changes consisted primarily of oedema and an influx of neutrophils into affected tissues and fluids. In a further eight infected cattle, increases in permeability of vessels associated with serosal surfaces were demonstrated by labelling with either colloidal carbon or Evans blue. Intravenous injections of carbon provided both macroscopic and histological labelling of affected vessels. Evans blue appeared to be more sensitive than carbon but did not provide a histological marker of vascular permeability and provided labelling of tissues rather than individual vessels. The main sites of increased permeability were synovial, pericardial, thoracic and abdominal serosae.

Clinical response of cattle to experimental infection with bovine ephemeral fever virus.

As part of a study of the pathology and pathogenesis of bovine ephemeral fever virus infection 44 cattle were infected by the intravenous injection of virulent virus. Thirty-eight animals responded clinically and detailed haematological and serological data were obtained from 10 of them. Inappetence was the only clinical sign observed before the onset of fever. The temperature response was characteristically biphasic, with the second peak occurring 12 to 24 hours after the first. The only consistent haematological response was an increase in the numbers of circulating neutrophils with a concurrent decline in the numbers of mononuclear leucocytes. There were no detectable changes in plasma or blood volume, packed cell volume, red cell count, haemoglobin concentration, serum calcium, magnesium, phosphorus and creatinine concentrations, or aspartate aminotransferase activity. Viraemia was demonstrated on either the first or second day of clinical disease and lasted for at most 48 hours. Low levels of neutralising antibody could be detected within one or two days after the cessation of viraemia. Six antibody-free animals did not respond clinically to injection with virulent virus, and did not develop detectable viraemia or a serum neutralising antibody response.

Squamous cell carcinoma of the tongue of the cat.

A case of squamous cell carcinoma of the tongue in an 11-year-old castrated male cat is described. The clinical signs of excessive salivation and inability to eat or drink were associated with enlargement of the tongue. The pathology, possible aetiology and pathogenesis of the neoplasm are discussed.

Development and trial of a bovine herpesvirus 1-thymidine kinase deletion virus as a vaccine.

An Australian bovine herpesvirus 1 (BHV1) isolate with a defined (427 base pair) deletion in the protein coding region of the thymidine kinase gene was obtained by standard marker rescue procedures. After selection in the presence of the nucleotide analogue 5'-iodo-deoxy-uridine the virus was analysed by hybridisation with three differential oligonucleotide probes, restriction endonuclease profile studies and DNA sequence analysis. The virus elicited an immune response in recipient animals after either intramuscular or intravenous administration and produced no significant deleterious side-effects when administered at a dose sufficient to stimulate the host immune response. The safety and immunogenicity of the recombinant BHV1 virus 39B1 were similar to those reported for other registered BHV1 vaccines and the virus would appear to be suitable for the production of a vaccine seed lot and more exhaustive field trials as a prelude to commercial vaccine production and registration.

Nursing futures: a process to promote change in the delivery of care.

In this era of healthcare reform, performing care using resources in an efficient manner is essential. "Nursing Futures," a process used by a 24-bed general rehabilitation unit in a 530-bed facility, helped the unit to identify key components of care, determine opportunities for improvement, and create a new system for the delivery of care that maximized resources and improved customer satisfaction. A Nursing Futures Committee, composed of nursing staff from all levels and from all shifts, used a continuous quality improvement process to focus on the problems in care delivery and developed ways to solve these problems using the time and talents of registered nurses in the most effective way. The committee also identified expectations of staff by various customer groups; analyzed the delivery system and defined its shortcomings; developed the ideal patient care unit within financial and institutional constraints; and executed the plan, considering cost and evaluation of patient and staff satisfaction before and after the system was implemented. The new system provided consistency in patient care assignments by reorganizing the unit into two nursing teams and by creating a new nursing position, the patient care manager.