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Biomedical subjects

S Davison

Publications and source records attributed to S Davison.

At least 19 recordsLinked to original sources

Postmenopausal hormone therapy: from monkey glands to transdermal patches.

The climacteric is not a condition of the modern age, although with increased life expectancy over the centuries, more women will experience this physiological transition. As women are living longer there is a greater expectation that good health will be maintained through to the late decade. Thus the potential long-term adverse health consequences of using hormonal therapies (HTs) to alleviate menopausal symptoms are of considerable concern for women and medical practitioners. This concern is often the basis for a decision whether or not to use HT. We have reviewed the history of knowledge of the menopause and the development of HT for the treatment of climacteric complaints. We have also summarised the current evidence for specific benefits and risks of HT. Data indicate that postmenopausal HT is appropriate for the management of vasomotor symptoms, but that HT should not be prescribed for the prevention of cardiovascular disease or dementia. HT does prevent bone loss and osteoporotic fracture; however, use for this purpose remains controversial. The risk of breast cancer with HT varies according to the preparation used, such that oestrogen without concurrent progestin appears to convey little, or possibly even no significant breast cancer risk. There is insufficient information regarding the long-term use of non-oral HT, low-dose HT or novel compounds such as tibolone or the selective oestrogen receptor modulators with respect to breast cancer and cardiovascular risk for specific recommendations to be made.

Administration, Cutaneous↗

Liver transplantation for a hilar inflammatory myofibroblastic tumor.

A 7-yr-old boy presented with obstructive jaundice secondary to an inflammatory myofibroblastic tumor centered on the hepatic hilum and extending into the liver. The tumor was further complicated by portal vein phlebitis and occlusion. Attempted resection of the tumor with portal vein reconstruction and bilioenteric drainage was unsuccessful and he required urgent orthotopic liver transplantation. In contrast to more peripheral inflammatory myofibroblastic tumors in the liver, hilar lesions are locally aggressive, causing occlusive portal phlebitis and biliary obstruction. Successful management may include the need for liver transplantation.

Child↗

Young male prisoners in a Young Offenders' Institution: their contact with suicidal behaviour by others.

Prison suicide rates are increasing. The impact of witnessing a suicide or how many people do so is unknown. The aim of this study was to find how many young people detained in a Young Offenders' Institution (YOI) have had contact with another's suicide attempt and to test for association between this and own self-harming behaviour. A questionnaire, developed for the project, was distributed within a YOI. 74% (355/480) responded. One hundred and fifty-one (43%) of the young men reported that they knew someone who had attempted suicide, 48 of them knowing someone who had thereby died. The contact with a non-fatal suicide attempted by others was associated with own self-harm (OR 1.73, CI 1.39-21.4, p<0.01); contact with completed suicide had no such association. The most important factor that increased the chance of knowing a suicide attempter was actual length of time spent in prison up to the time of the study; 95 (63%) of the young men with such contact had it in prison. No other significant vulnerability factors were identified. It seems likely that imprisonment is a specific vulnerability factor for self-harm, one explanation being that it increases the risk of exposure to a contact with suicidal behaviour by others. Further work is called for to test relationships between such exposure and own behaviour over time, and to gather first hand accounts from the young men in such circumstances in order to understand the meaning for them of the contact with suicidal behaviour by others. This would inform appropriate intervention strategies, and could save much morbidity, and even mortality.

Adolescent↗

Epidemiology, production losses, and control measures associated with an outbreak of avian influenza subtype H7N2 in Pennsylvania (1996-98).

An outbreak of H7N2 low-pathogenicity (LP) avian influenza (AI) occurred in a two-county area in Pennsylvania from December of 1996 through April of 1998. The outbreak resulted in infection of 2,623,116 commercial birds on 25 premises encompassing 47 flocks. Twenty-one (one premise with infection twice) of the twenty-five infected premises housed egg-laying chickens and one premise each had turkeys, layer pullets, quail, and a mixed backyard dealer flock. Despite dose proximity of infected flocks to commercial broiler flocks, no infected broilers were identified. Experimentally, when market age broilers were placed on an influenza-infected premise they seroconverted and developed oviduct lesions. The outbreak was believed to have originated from two separate introductions into commercial layer flocks from premises and by individuals dealing in sales of live fowl in the metropolitan New York and New Jersey live-bird markets. Source flocks for these markets are primarily in the northeast and mid-Atlantic areas, including Pennsylvania. Mixed fowl sold include ducks, geese, guinea hens, quail, chukar partridges, and a variety of chickens grown on perhaps hundreds of small farms. Infections with the H7N2 AI virus were associated with variable morbidity and temporary decreases in egg production ranging from 1.6% to 29.1% in commercial egg-laying chickens. Egg production losses averaged 4.0 weeks duration. Mortality ranged from 1.5 to 18.3 times normal (mean of 4.3 times normal). Duration of mortality ranged from 2 to 13 weeks (average of 3.9 weeks) in flocks not depopulated. Lesions observed were primarily oviducts filled with a mucous and white gelatinous exudates and atypical egg yolk peritonitis. Quarantine of premises and complete depopulation were the early measures employed in control of this outbreak. Epidemiological studies suggested that depopulation furthered the spread of influenza to nearby flocks. Thereafter, later control measures included quarantine, strict biosecurity, and controlled marketing of products.

Animals↗

Validation of egg yolk antibody testing as a method to determine influenza status in white leghorn hens.

Determination of the avian influenza (AI) status of a flock has traditionally been done by detection of serum antibodies. However, for many diseases, detection of antibodies in egg yolk has been effective in monitoring the disease status of laying flocks. This study compared the utility of egg yolk vs. serum for determining AI status in laying hen flocks. Specific-pathogen-free white leghorn hens were inoculated via the respiratory tract with a low-pathogenic H7N2 AI virus or sterile allantoic fluid or subcutaneously with an inactivated oil emulsion vaccine produced from the same AI virus or normal allantoic fluid. Antibody levels were determined by the agar gel immunodiffusion (AGID) test, the hemagglutination-inhibition (HI) test, and the enzyme-linked immunosorbent assay (ELISA). Anti-influenza antibodies were detected in sera of all live virus-inoculated hens by day 7 postinoculation (PI) (AGID and ELISA tests), but detection of antibodies in egg yolk was delayed by a few days, with all being positive by day 14 PI. Sera from all vaccinated hens were positive by day 14 PI (AGID and ELISA tests), and egg yolk was positive by day 18 PI. The HI test was less sensitive than the ELISA and AGID tests in detecting anti-influenza antibodies in both sera and yolk. Serum and yolk from all control birds remained negative throughout the study. These studies show that currently used serologic tests can detect antibodies in serum and yolk samples from hens exposed to live AI virus or from those that have been vaccinated. Antibody is detected earlier in the serum than in the yolk and antibody is detected earlier from birds exposed to a live infection compared to birds vaccinated with an inactivated oil emulsion vaccine.

Animals↗

Summary of the 2001-02 Pennsylvania H7N2 low pathogenicity avian influenza outbreak in meat type chickens.

H7N2 low-pathogenicity (LP) avian influenza (AI) virus was isolated from chickens submitted to the Pennsylvania Animal Diagnostic Laboratory System on December 4 and 5, 2001. The cases were from two broiler breeder flocks in central Pennsylvania that had clinical signs of an acute, rapidly spreading respiratory disease. Seroconversion to AI virus was detected on follow-up sampling. Subsequently, H7N2 LPAI virus was isolated in five different broiler flock cases submitted between December 14, 2001, and January 3, 2002. Clinical signs and lesions in broilers, when present, were compatible with multicausal respiratory disease. With the exception of one broiler flock that was processed, birds from all of the virus positive flocks were euthanatized in-house within 11 days of the original case submission date. Increased surveillance of poultry flocks within 10-mile radius zones centered at the foci of the positive farms continued until March 1, 2002. No additional cases were detected.

Animals↗

A review of the 1996-98 nonpathogenic H7N2 avian influenza outbreak in Pennsylvania.

The nonpathogenic avian influenza (AI) outbreak in Pennsylvania began in December 1996 when there was a trace back from a New York live bird market to a dealer's flock. A total of 18 commercial layer flocks, two commercial layer pullet flocks, and a commercial meat turkey flock were diagnosed with nonpathogenic AI (H7N2) viral infection with an economic loss estimated at between 3 and 4 million dollars. Clinical histories of flocks infected with the disease included respiratory disease, elevated morbidity and mortality throughout the house, egg production drops, depression, and lethargy. A unique gross lesion in the commercial layers was a severe, transmural oviduct edema with white to gray flocculent purulent material in the lumen. Layer flocks on two separate premises were quarantined but permitted to remain in the facilities until cessation of virus shed was determined through virus isolation. Several months later, clinical AI appeared again in these flocks. It is not known whether the recurrence of disease in these cases is due to persistence of the organism in the birds or the environment. In addition to serologic testing and virologic testing by chicken embryo inoculation, an antigen capture enzyme immunoassay was evaluated as a diagnostic tool for AI. Research projects related to disinfection, burial pits, and geographical system technology were developed because of questions raised concerning transmission, diagnosis, and control of nonpathogenic AI (H7N2).

Animals↗

Coeliac disease and liver dysfunction.

The spectrum and pathogenesis of liver dysfunction in coeliac disease (CD) is reviewed. CD and liver disease share common risk factors, and consequences of CD may cause liver dysfunction. Liver dysfunction should be sought in CD, and its aetiology explored when abnormalities persist after gluten exclusion. CD should be excluded in patients with unexplained liver dysfunction before being labelled "cryptogenic".

Autoimmune Diseases↗

Identification, sequence analysis, and phylogeny of the immediate early gene 1 of the Trichoplusia ni single nucleocapsid polyhedrosis virus.

Substantial research has been conducted on the immediate early I (ie-1) genes from the prototype baculovirus Auographa californica multicapsid nuclear polyhedrosis virus (AcMNPV) and the Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV). In both cases ie-1 gene products have been implicated in transcriptional activation and repression. In this study an ie-1 homolog was identified from Trichoplusia ni single nucleocapsid polyhedrosis virus (TniSNPV). Nucleotide sequence analysis indicated that the TniSNPV ie-1 gene consists of a 2,217 nucleotide open reading frame (ORF), encoding a protein with a molecular mass of 84.464 kDa. This represents the largest baculovirus ie-1 gene characterised to date. Of the seven ie-1 homologs identified to date, the TniSNPV ie-1 shared most sequence similarity with the ie-1 gene of Spodoptera exigua MNPV (SeMNPV) (41%). At the nucleotide level, expected TATA and CAGT motifs were found to precede each ie-1 ORE. At the protein level, it was confirmed that the N-termini are poorly conserved, but share the characteristic of having a high proportion of acidic amino acids. In addition it was found that N-terminal regions significantly matched the SET domain in the Swiss-Prot prosite database. The C-terminal regions of the deduced IE-1 sequences were found to be substantially more conserved than the N-termini. Several conserved motifs were identified in the C-terminal sequences. A phylogenetic tree of nine baculovirus IE-1 proteins was constructed using maximum parsimony analysis. The phylogenetic estimation of the ie-1 genes shows that TniSNPV is a member of the previously described lepidopteran NPV group II and it is most closely related to SeMNPV.

Amino Acid Sequence↗

Corneodesmosin expression in psoriasis vulgaris differs from normal skin and other inflammatory skin disorders.

SUMMARY: Corneodesmosin (Cdsn) is a late differentiation epidermal glycoprotein putatively involved in keratinocyte adhesion. The Cdsn gene lies within the susceptibility region on chromosome 6p21.3 (PSORS1) for psoriasis, a common chronic disfiguring skin disease. A particular allelic variant of Cdsn has a strong association with psoriasis. Therefore, genetically and biologically, Cdsn is a possible candidate gene for psoriasis susceptibility. To investigate a potential role for Cdsn in psoriasis pathogenesis, protein expression studies were performed by quantitative immunohistochemistry on normal skin, psoriatic skin (lesional and nonlesional), and other skin disorders using monoclonal antibodies (G36-19 and F28-27). In normal and nonlesional skin, Cdsn was expressed in stratum corneum and one or two layers of superficial stratum granulosum. In lesional psoriasis, there was a significant increase in Cdsn expression, which was observed in multiple layers of stratum spinosum and in stratum corneum. The expression pattern varied from granular, cytoplasmic immunoreactivity to cell surface labeling with weakly immunoreactive cytoplasm. In chronic atopic dermatitis, lichen planus, mycosis fungoides, and pityriasis rubra pilaris, Cdsn immunoreactivity was confined to stratum corneum and upper stratum granulosum with no stratum spinosum immunoreactivity. Immunoelectron microscopy of normal and lesional psoriatic skin demonstrated Cdsn release concomitant with involucrin incorporation into cell envelopes and completed before mature envelope formation. Extracellular release of Cdsn occurred at a lower level of the epidermis in psoriasis than normal skin. These protein expression studies provide evidence of altered Cdsn expression in psoriasis consistent with a role of Cdsn in disease pathogenesis. Further functional and genetic studies of Cdsn are justified to determine its role as a potential psoriasis-susceptibility factor.

Chromosomes, Human, Pair 6↗

Management of a pregnant patient with Graves' disease complicated by thionamide-induced neutropenia in the first trimester.

A 31-year-old woman presented with neutropenia due to thionamide drug therapy for Graves' disease. She also reported 8 weeks of amenorrhoea and had a positive pregnancy test. Her drug therapy was discontinued and her neutropenia resolved uneventfully. The hyperthyroidism recurred a week later. After consideration of all treatment options, it was decided to observe until 14 weeks when an elective thyroidectomy was planned. Mother and fetus were monitored closely and both tolerated moderate hyperthyroidism well. At 14 weeks the patient underwent a total thyroidectomy after rendering her euthyroid with a short course of sodium ipodate. Labour was induced at 41 weeks. Delivery was complicated by fetal distress and precipitated a forceps delivery. A 3250 g male infant was born with poor Apgar score and required 2 h of ventilation. At 1 year, the child had reached all developmental milestones at appropriate times. Both mother and fetus may tolerate moderate thyrotoxicosis well in early pregnancy, an alternative that should be considered when thionamide drug therapy is contraindicated.

Adult↗

The arabidopsis ISR1 locus controlling rhizobacteria-mediated induced systemic resistance is involved in ethylene signaling.

In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers an induced systemic resistance (ISR) response that is effective against different types of pathogens. The ISR signaling pathway functions independent of salicylic acid, but requires responsiveness to jasmonate (JA) and ethylene. Using the genetic variability of ISR inducibility between Arabidopsis accessions, we recently identified a locus (ISR1) on chromosome III that is involved in ISR signaling. Accessions RLD and Wassilewskija (Ws) are recessive at the ISR1 locus and are, therefore, unable to develop ISR. Here we investigated whether the ISR1 locus is involved in JA or ethylene signaling. Compared with the ISR-inducible accession Columbia (Col), accessions RLD and Ws were not affected in JA-induced inhibition of root growth and expression of the JA-responsive gene Atvsp, suggesting that the ISR1 locus is not involved in JA signaling. However, RLD and Ws showed an affected expression of the triple response and a reduced expression of the ethylene responsive genes Hel and Pdf1.2 after exogenous application of the ethylene precursor 1-aminocyclopropane-1-carboxylate. Moreover, in contrast to Col, RLD and Ws did not develop resistance against P. syringae pv. tomato DC3000 after treatment of the leaves with 1-aminocyclopropane-1-carboxylate. Analysis of the F(2) and F(3) progeny of a cross between Col (ISR1/ISR1) and RLD (isr1/isr1) revealed that reduced sensitivity to ethylene cosegregates with the recessive alleles of the ISR1 locus. These results suggest that the ISR1 locus encodes a component of the ethylene response, which is required for the expression of rhizobacteria-mediated ISR.

Acetates↗

Detection of acute bee paralysis virus and black queen cell virus from honeybees by reverse transcriptase pcr.

A reverse transcriptase PCR (RT-PCR) assay was developed for the detection of acute bee paralysis virus (ABPV) and black queen cell virus (BQCV), two honeybee viruses. Complete genome sequences were used to design unique PCR primers within a 1-kb region from the 3' end of both genomes to amplify a fragment of 900 bp from ABPV and 700 bp from BQCV. The combined guanidinium thiocyanate and silica membrane method was used to extract total RNA from samples of healthy and laboratory-infected bee pupae. In a blind test, RT-PCR successfully identified the samples containing ABPV and BQCV. Sensitivities were approximately 1,600 genome equivalents of purified ABPV and 130 genome equivalents of BQCV.

Animals↗

Sacbrood virus of the honeybee (Apis mellifera): rapid identification and phylogenetic analysis using reverse transcription-PCR.

Sacbrood virus (SBV) infects larvae of the honeybee (Apis mellifera), resulting in failure to pupate and death. Until now, identification of viruses in honeybee infections has been based on traditional methods such as electron microscopy, immunodiffusion, and enzyme-linked immunosorbent assay. Culture cannot be used because no honeybee cell lines are available. These techniques are low in sensitivity and specificity. However, the complete nucleotide sequence of SBV has recently been determined, and with these data, we now report a reverse transcription-PCR (RT-PCR) test for the direct, rapid, and sensitive detection of these viruses. RT-PCR was used to target five different areas of the SBV genome using infected honeybees and larvae originating from geographically distinct regions. The RT-PCR assay proved to be a rapid, specific, and sensitive diagnostic tool for the direct detection of SBV nucleic acid in samples of infected honeybees and brood regardless of geographic origin. The amplification products were sequenced, and phylogenetic analysis suggested the existence of at least three distinct genotypes of SBV.

Amino Acid Sequence↗

Epstein-Barr virus infection in paediatric liver transplant recipients: detection of the virus in post-transplant tonsillectomy specimens.

AIMS: Post-transplant lymphoproliferative disease (PTLD) is an important and serious complication in transplant patients. Recent studies have suggested that quantitative assessment of Epstein-Barr virus (EBV) infection in transplant patients might help to identify those at risk of developing PTLD. Therefore, tonsils from paediatric liver transplant recipients were studied for evidence of EBV infection. METHODS: Tonsils were studied by in situ hybridisation for the detection of the small EBV encoded nuclear RNAs (EBERs). The phenotype of EBV infected cells was determined by double labelling in situ hybridisation and immunohistochemistry. The expression of viral latent and lytic antigens was determined by immunohistochemistry. Tonsils from patients without known immune defects were studied as controls. RESULTS: Tonsils from transplant patients showed pronounced follicular hyperplasia and minor paracortical hyperplasia. In situ hybridisation revealed variable numbers of EBV infected B cells in the tonsils from transplant patients (range, 2-1000/0.5 cm(2); mean, 434/0.5 cm(2); median, 105/0.5 cm(2)). Lower numbers were detected in the control tonsils (range, 1-200/0.5 cm(2); mean, 47/0.5 cm(2); median, 9/0.5 cm(2)). The latent membrane protein 1 (LMP1) of EBV was not detected and there were only rare cells in two cases showing expression of the EBV encoded nuclear antigen 2 (EBNA2). There was no evidence of lytic infection. None of the patients developed PTLD within a follow up period of up to five years. CONCLUSIONS: These data indicate that tonsillar enlargement in paediatric liver transplant patients does not necessarily imply a diagnosis of PTLD. Furthermore, the presence of increased numbers of EBV infected cells in tonsils from liver transplant recipients by itself does not indicate an increased risk of developing PTLD.

Antigens, Viral↗

Examination of the screening properties of the personality diagnostic questionnaire 4+ (PDQ-4+) in a prison population.

There is a high prevalence of personality disorder in most prison populations. Many pass through the system undiagnosed. A screening instrument would improve identification. This study examined the screening properties of the Personality Diagnostic Questionnaire-4+ (PDQ-4+) in prisoners convicted of violent and sexual offenses. A sample of British prisoners completed the self-report PDQ-4+ and were interviewed using the Structured Clinical Interview for DSM-IV Axis II disorders. When used to generate a total score, the PDQ-4+ had an acceptable overall accuracy as measured by the area under the Receiver Operating Characteristics (ROC) curve. The PDQ-4+ appears to have the properties suitable for use as a screening instrument, particularly when screening for the presence or absence of personality disorder rather than for individual personality disorder categories. A graph is presented from which choices of cut-off score for different combinations of sensitivity and specificity can be made. A cut off total score of 25 or above yielded near optimal sensitivity and specificity. The suggested cut off score for this population is lower than that previously suggested.

Adult↗

Analysis of the complete genome sequence of acute bee paralysis virus shows that it belongs to the novel group of insect-infecting RNA viruses.

The complete genome sequence of acute bee paralysis virus (ABPV) was determined. The 9470 nucleotide, polyadenylated RNA genome encoded two open reading frames (ORF1 and ORF2), which were separated by 184 nucleotides. The deduced amino acid sequence of the 5' ORF1 (nucleotides 605 to 6325) showed significant similarity to the RNA-dependent RNA polymerase, helicase, and protease domains of viruses from the picornavirus, comovirus, calicivirus, and sequivirus families, as well as to a novel group of insect-infecting RNA viruses. The 3' ORF2 (nucleotides 6509-9253) was proposed as encoding a capsid polyprotein with three major structural proteins (35, 33, and 24 kDa) and a minor protein (9.4 kDa). This was confirmed by N-terminal sequence analysis of two of these proteins. The overall genome structure of ABPV showed similarities to those of Drosophila C virus, Plautia stali intestine virus, Rhopalosiphum padi virus, and Himetobi P virus, which have been classified into a novel group of picorna-like insect-infecting RNA viruses called cricket paralysis-like viruses. It is suggested that ABPV belongs to the cricket paralysis-like viruses.

Amino Acid Sequence↗