Galactic cosmic radiation exposure causes multifaceted neurocognitive impairments.

Technological advancements have facilitated the implementation of realistic, terrestrial-based complex 33-beam galactic cosmic radiation simulations (GCR Sim) to now probe central nervous system functionality. This work expands considerably on prior, simplified GCR simulations, yielding new insights into responses of male and female mice exposed to 40-50 cGy acute or chronic radiations relevant to deep space travel. Results of the object in updated location task suggested that exposure to acute or chronic GCR Sim induced persistent impairments in hippocampus-dependent memory formation and reconsolidation in female mice that did not manifest robustly in irradiated male mice. Interestingly, irradiated male mice, but not females, were impaired in novel object recognition and chronically irradiated males exhibited increased aggressive behavior on the tube dominance test. Electrophysiology studies used to evaluate synaptic plasticity in the hippocampal CA1 region revealed significant reductions in long-term potentiation after each irradiation paradigm in both sexes. Interestingly, network-level disruptions did not translate to altered intrinsic electrophysiological properties of CA1 pyramidal cells, whereas acute exposures caused modest drops in excitatory synaptic signaling in males. Ultrastructural analyses of CA1 synapses found smaller postsynaptic densities in larger spines of chronically exposed mice compared to controls and acutely exposed mice. Myelination was also affected by GCR Sim with acutely exposed mice exhibiting an increase in the percent of myelinated axons; however, the myelin sheathes on small calibur (< 0.3 mm) and larger (> 0.5 mm) axons were thinner when compared to controls. Present findings might have been predicted based on previous studies using single and mixed beam exposures and provide further evidence that space-relevant radiation exposures disrupt critical cognitive processes and underlying neuronal network-level plasticity, albeit not to the extent that might have been previously predicted.

Atypical Brucella sp in captive Australian green tree frogs (Litoria caerulea): clinical features, pathology, culture and molecular characterization.

BACKGROUND: Brucella spp. are globally important zoonotic bacteria, which have historically been considered pathogens of warm-blooded species. More recently, new strains of Brucella have been cultured from a broader range of animals including terrestrial and marine mammals and amphibians. These new isolates are classified as 'atypical' brucellae and differ from the classical stains by host tropism, phenotypic traits or phylogenetic distance. Atypical Brucella have previously been described as the cause of localised and systemic infection in frogs. CASE REPORT: This report describes the clinical features, pathology, microbiology and molecular characteristics of persistent Brucella spp. infection in two Australian green tree frogs and its isolation in an additional in-contact, clinically well frog. CONCLUSION: The two frogs that died had severe nephritis attributed to brucellosis with disseminated infection identified in one animal.

Metastatic mineralisation caused by vitamin D intoxication in hand-raised short-beaked echidnas (Tachyglossus aculeatus).

CASE REPORT: Two cases of metastatic mineralisation caused by dietary excess of vitamin D are reported in hand-raised short-beaked echidna (Tachyglossus aculeatus) puggles at the Australian Wildlife Health Centre. Oversupplementation was attributed to excessive levels of vitamin D in Wombaroo Echidna Milk Replacer fed to the puggles. No information exists regarding the naturally occurring vitamin D levels in echidna milk, but, given the low serum levels that have been observed in free-ranging animals, it is likely to be low. CONCLUSION: The vitamin D concentration in Wombaroo Echidna Milk Replacer has been reduced.

Atypical scrapie in Australia.

BACKGROUND: Since its initial detection in Norway in 1998, atypical scrapie ('atypical/Nor98 scrapie') has been reported in sheep in the majority of European countries (including in regions free of classical scrapie) and in the Falkland Islands, the USA, Canada, New Zealand and Australia. CASE SERIES: The diagnosis in Australia of atypical scrapie in four Merino and one Merino-cross sheep showing clinical signs of neurological disease was based on the detection of grey matter neuropil vacuolation (spongiform change) in the brain (particularly in the molecular layer of the cerebellar cortex) and associated abnormal prion protein (PrPSc ) deposition in both grey and white matter. Changes were minimal in the caudal brainstem, the predilection site for lesions of classical scrapie. CONCLUSION: The distinctive lesion profile of atypical scrapie in these five sheep highlights the diagnostic importance of routine histological evaluation of the cerebellum for evidence of neuropil vacuolation and associated PrPSc deposition in adult sheep with suspected neurological disease.

Fatal columbid herpesvirus-1 infections in three species of Australian birds of prey.

We document columbid herpesvirus-1 (CoHV-1) infection in two barking owls (Ninox connivens), a powerful owl (Ninox strenua) and an Australian hobby (Falco longipennis). Antemortem signs of infection were non-specific and the birds either died soon after they were identified as ill or were found dead unexpectedly. Gross postmortem findings were also not specific. Microscopically, marked to massive splenic and hepatic necrosis with the presence of eosinophilic inclusion bodies in remaining splenocytes and hepatocytes was found in all birds. Herpesvirus virions were identified in liver sections from one of the boobook owls by electron microscopy. Using CoHV-1-specific primers and polymerase chain reaction, CoHV-1 DNA was amplified from tissue samples from all birds. A comparison of these sequences to previously reported sequences of CoHV-1 found them to be identical or to vary by a single base pair. These findings increase the number of known species of birds of prey that are susceptible to CoHV-1 infection and indicate that rock pigeons (Columbia livia) should not be included in the diet of captive Australian birds of prey.

Can a participatory approach contribute to food chain risk analysis?

We consider food chain risks and specifically address stakeholder participation in the risk analysis process. We combine social and natural science perspectives to explore the participation process in relation to food risks and, in particular, to consider how some specific participation processes might be scientifically evaluated and how stakeholder participation in general might be incorporated into food risk decision making. We have built considerations based on three large integrative case studies that examine aspects of participatory processes. Here we use the case studies collectively to illustrate observations and beliefs concerning the nature of the interaction of stakeholders with established quantitative risk methodologies. This account is not supported by any large volume of analysis. The views in the report are expressed in relation to an accepted risk analysis framework and also with respect to probabilistic modeling of risks and are illustrated where possible with anecdotal reports of actual case study events.

Malakoplakia in the urinary bladder of a kitten.

Malakoplakia is a form of chronic granulomatous inflammation that in humans most commonly affects the urinary bladder of middle-aged women. Naturally occurring malakoplakia is rare in animals, having been described twice in the pig only. An 8-week-old kitten was diagnosed with malakoplakia of the urinary bladder after a 3-week history of dysuria. Post-mortem examination revealed a markedly enlarged bladder with a diffusely nodular mucosal surface. Microscopically, there was diffuse submucosal infiltration by histiocytes stained positively by periodic acid Schiff (PAS) and described in the human condition as "von Hansemann cells". Intracellular and extracellular "Michaelis-Gutman" inclusion bodies were seen on light and electron microscopical examination. These structures are considered pathognomonic for malakoplakia. The pathogenesis of malakoplakia is enigmatic. Defective function of phagolysosomes is currently suspected to underlie the abnormal accumulation of submucosal histiocytes; however the primary functional defect remains unknown.

Patients' perspective of pathology specimens. A prospective study.

AIM: To determine the degree of patients' interest in surgical pathology specimens. To assess the impact of patients' involvement in surgical pathology on their understanding of (and confidence in) the storage and use of pathology specimens. METHODS: Forty seven patients were invited to visit the pathology department and view their specimens postoperatively. Those who visited were asked to complete a questionnaire to assess the effect of the visit. RESULTS: Thirty three of the 47 patients wished to view their specimens, but only 14 actually made the visit. All those who visited indicated that it made them better able to understand the reason for surgery and tissue retention issues, and more likely to consent to the use of excess tissue for research. CONCLUSION: In general, patients are keen to know what happens to and what is wrong with the organs removed at surgery, and their involvement in surgical pathology can have positive and beneficial effects both for themselves and the profession.

Women's reproductive health. A Catholic perspective.

PIP: That Catholic hospitals refuse to perform abortions and in vitro fertilization is against Church teaching cause many people to doubt that Catholic health care institutions work to the benefit of women's reproductive health. Women's reproductive health, however, goes beyond certain controversial procedures and is directly related to overall health. Catholic hospitals and systems want appropriate, comprehensive care for all members of society; they are working upon general health care reform to achieve that goal. Abortion and contraception are seen as different issues by the Catholic Church. Abortion is forbidden by the Church and contraception is not promoted by Catholic facilities, but the Catholic sponsorship of a physician office practice does not mean that no physician in it can discuss or prescribe contraceptives. That issue involves the confidentiality of the physician-patient relationship, which Catholic sponsors respect.^ieng

Our world views (may be) incommensurable: now what?

In focusing their view on Kuhn, Robert Veatch and William Stempsey ignore alternative sources of insight from other voices that could help move us beyond incommensurability. Richard Rorty and Helen Longino, for example, offer another view of science and objectivity with constructive insight for the practice of science and medicine.

Cre recombinase-mediated site-specific recombination between plant chromosomes.

We report the use of the bacteriophage P1 Cre-lox system for generating conservative site-specific recombination between tobacco chromosomes. Two constructs, one containing a promoterless hygromycin-resistance gene preceded by a lox site (lox-hpt) and the other containing a cauliflower mosaic virus 35S promoter linked to a lox sequence and the cre coding region (35S-lox-cre), were introduced separately into tobacco plants. Crosses between plants harboring either construct produced plants with the two constructs situated on different chromosomes. Plants with recombination events were identified by selecting for hygromycin resistance, a phenotype expressed upon recombination. Molecular analysis showed that these recombination events occurred specifically at the lox sites and resulted in the reciprocal exchange of flanking host DNA. Progenies of these plants showed 67-100% cotransmission of the new transgenes, 35S-lox-hpt and lox-cre, consistent with the preferential cosegregation of translocated chromosomes. These results illustrate that site-specific recombination systems can be useful tools for the large-scale manipulation of eukaryotic chromosomes in vivo.

Homeopathy.

Homeopathy is a form of complementary medicine which relies heavily on observation and experience. The three distinguishing characteristics of homeopathy are that remedies are prescribed on the totality of a person's symptoms, that the remedy likely to cure a person is a dilution of that substance which would cause the same symptoms in a healthy person, and that remedies are prepared using microdoses of substances which are diluted and then vigorously shaken. Mainstream medicine criticizes homeopathy by saying that its gentleness has outlived its usefulness and treatment successes are probably no more than placebo action. In addition, its critics charge that homeopathy is unscientific, runs counter to the "laws of nature" and will not stand up to scientific scrutiny. Homeopaths reply that mainstream medicine is dangerous, that homeopathy works in children and animals (usually thought resistant to placebo), and that several good controlled clinical trials have shown positive results. There is a difference between showing that homeopathy works and adequately accounting for its mechanism of action. Clinical trials have concentrated on the former and remain unexplained in the latter.

How best shall we serve? Case study.

KIE: Four disparate proposals for hospital programs, varying in their funding requirements and revenue-generating capacity, have been made to the chief executive officer (CEO) of a metropolitan nonprofit general hospital that has always prided itself on being responsive to community needs. Although the hospital faces severe financial pressures, the CEO has determined that one of the proposals can be supported. Three commentaries on this case discuss what ethical criteria should be considered in evaluating the four proposals, and what role the hospital ethics committee should play in the decision.^ieng

Exchange of gene activity in transgenic plants catalyzed by the Cre-lox site-specific recombination system.

The Cre-lox site-specific recombination system of bacteriophage P1 was used to excise a firefly luciferase (luc) gene which had previously been incorporated into the tobacco genome. The excision event was due to site-specific DNA recombination between two lox sequences flanking the luc gene and was catalyzed by the Cre recombinase introduced by cross-fertilization. Recombination resulted in the fusion of a promoter with a distally located hygromycin phosphotransferase (hpt) coding sequence and the excision event was monitored as a phenotypic change from expression of luc to expression of hpt. The efficiency of recombination was estimated from the exchange of gene activity and confirmed by molecular analysis. The relevance to potential applications of site-specific deletion-fusion events for chromosome engineering are discussed.

Engineering 2,4-D resistance into cotton.

To reduce damage by drift-levels of the herbicide 2,4-dichlorophenoxyacetic acid, we have engineered the 2,4-D resistance trait into cotton (Gossypium hirsutum L.). The 2,4-D monooxygenase gene tfdA from Alcaligenes eutrophus plasmid pJP5 was isolated, modified and expressed in transgenic tobacco and cotton plants. Analyses of the transgenic progeny showed stable transmission of the chimeric tfdA gene and production of active 2,4-D monooxygenase. Cotton plants obtained were tolerant to 3 times the field level of 2,4-D used for wheat, corn, sorghum and pasture crops.

Structure and chromosomal localization of the gene for the oligodendrocyte-myelin glycoprotein.

Utilizing a cDNA clone encoding the oligodendrocyte-myelin glycoprotein (OMgp) to screen a human genomic DNA library, we have obtained a clone that contains the OMgp gene. The genomic clone was restriction mapped and the OMgp gene and its 5' and 3' flanking regions were sequenced. A single intron is found in the 5' untranslated region of the gene, while the coding region is uninterrupted by an intron. This placement of a single intron in the OMgp gene is identical to that of the gene for the alpha-chain of platelet glycoprotein Ib, which, along with OMgp, belongs to a family of proteins sharing two distinct structural domains: an NH2-terminal cysteine-rich domain and an adjacent domain of tandem leucine-rich repeats. Hence, it is possible that this family of proteins is not only related in terms of primary structure, but also through similar gene structure. Sequence comparison of the 5' and 3' flanking regions did not reveal striking similarities to other DNA sequences, and no obvious promoter elements were noted. By hybridization of the genomic clone to metaphase cells, we have localized the human OMgp gene to chromosome 17 bands q11-12, a region to which the neurofibromatosis type 1 gene has been previously mapped.

A system of values. Values committees help a system preserve its mission.

In response to the challenge of maintaining their Christian values in the face of increasing economic pressures, St. Joseph Health System in Orange, CA, has implemented its VISION program (Values Integration Systemwide in Ongoing Networking). The program consists of values implementation policies, self-assessment, and regular systemwide reporting. The idea for evaluating values implementation took shape in 1987 at a representative task force meeting. After agreeing on a conceptual framework, the group recommended the formation of values committees to assess their organizations' status and develop action plans. The task force provided the first step by identifying nine areas for self-assessment. The committees met in January 1988 to examine their tasks and share ideas. They were encouraged to translate the values concepts into actual attitudes and behaviors that could be applied in their work. Later they gauged the relative stages of their entities' values implementation through surveys, assessments, and interaction.