Biomedical subjects

C Dawson

Publications and source records attributed to C Dawson.

At least 37 records · Page 2Linked to original sources

PubMed1998

Screening for tuberculosis in jail and clinic follow-up after release.

OBJECTIVES: The purpose of this study was to describe tuberculosis (TB) screening and preventive therapy in the San Francisco County Jail and to measure the follow-up rate at the public health department TB clinic. METHODS: The records of male inmates screened for 6 months in 1994 were reviewed. Those prescribed isoniazid and released before therapy ended were matched with TB clinic records. Inmates were considered to have followed up if they came to the TB clinic within 1 month of release. RESULTS: Of 3352 inmates screened, 553 (16.5%) reported a prior positive skin test, and 330 (26.9%) of 1229 tests placed and read were positive. Of those with positive tests, 151 (45.8%) began isoniazid. Most of the inmates were foreign-born Hispanics (80.8%). Ninety-three (61.6%) inmates were released before completion, after an average of 68.5 days. Three (3.2%) went to the TB clinic within a month. CONCLUSIONS: Jail represents an important screening site for TB, but care is not continued after release. Strategies are needed to enhance the continuity of isoniazid preventive care.

Adult↗

PubMed1997

Serological prevalence of Hypoderma species in cattle in Great Britain (1995/96) and the relative value of serological surveillance over clinical observation.

Sera from 100,400 cattle on 2850 farms in England, Scotland and Wales were tested for the presence of antibodies to Hypoderma species between the end of November 1995 and the end of February 1996. Twelve animals were resampled because the initial results were equivocal but only one of them was confirmed as seropositive. This animal was a bull imported from Belgium which had been treated with an approved warble fly treatment within 24 hours of arrival at its destination in Great Britain. No seropositive animals were confirmed within the native British cattle population. Statistical analysis of these data indicates that the probable maximum number of infested cattle herds in Great Britain is 112. To detect the disease by direct clinical observation would require more than 500 herds to be infested, indicating that the serological testing of this number of cattle and farms is more than four times as sensitive as clinical observation for the detection of hypodermosis.

Animals↗

PubMed1997

Posterior tibial somatosensory evoked potentials in very preterm infants.

Cortical posterior tibial somatosensory (SSEP) responses were reliably recorded from 67 infants of 33 weeks gestation or less who had normal neurological outcome at 24 months corrected age. Cross-sectional and longitudinal data did not show a change in waveform morphology with advancing gestation or postnatal age. The latency of the first cortical component shortened as maturation increased. This study provides normative data for the peak component waveforms of the response in very preterm infants. The role of the posterior tibial SSEP in the prediction of functional brain injury in this high risk population can now be determined.

Cross-Sectional Studies↗

PubMed1997

Social interaction alters attraction to competitor's odour in the mouse Mus spretus Lataste

When animals defend territories that are large and structurally complex, scent marks alone are unlikely to be reliable signals of a resident's dominance and competitors should require initial proof through direct interaction. This was tested using freshly captured Mus spretus which occupy large non-overlapping ranges in grassland but are strongly attracted to substrate odours from unfamiliar competitors. Choice tests measured time spent investigating and chewing to gain access to paired nestboxes when the entrances were blocked with mesh. Experiment 1 established that mice of both sexes were more strongly attracted to their own odour than to a clean site. Experiment 2 examined choice between the subject's own odour and that of an unfamiliar same-sex competitor both before and after meeting the competitor in a neutral (clean) arena. Prior to interaction, males exerted much effort to gain access to both their own and their unfamiliar competitor's odour. Once relative dominance had been established through agonistic interaction, subordinates avoided their dominant competitor's odour in favour of their own while dominants continued to be attracted to both. There was little aggressive competition between unfamiliar females and relative status did not affect their attraction to a competitor's odour. Females tended to be more attracted to a competitor's odour than to their own prior to interaction but showed less attraction to a competitor's odour post-interaction. A third experiment showed that the odour of an unfamiliar male was more attractive than that from an unfamiliar female, especially to males. The consequences of these responses for maintaining spatial dispersion in this species are discussed.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Journal Article↗

PubMed1997

A competitive ELISA for the serodiagnosis of hypodermosis.

Hypodermosis is a parasitic disease of cattle caused by Hypoderma lineatum and H. bovis. It is an important health and welfare problem of infested cattle and a cause of considerable economic loss. In live animals, detection can be either by direct clinical examination of infested cattle and palpation of second and third stage larvae in the back or by the use of serological methods. This paper describes a competitive ELISA for the detection of antibodies to Hypoderma species in cattle sera. It has been validated using a small panel of 40 samples from clinically positive cattle and 200 samples from clinically negative (unexposed) cattle from a warble free area. Sensitivity and specificity calculated from this panel were 100% and 92% respectively at 2 SD from the mean or 92.5% and 98.5% at 3 SD from the mean. The use of serology and direct clinical examination of affected cattle, are discussed as methods for monitoring hypodermosis. The competitive ELISA should prove a useful adjunct to the standard sandwich ELISA, particularly in the resolution of samples which display non-specific binding properties.

Animals↗

PubMed1997

Association between time homeless and perceived health status among the homeless in San Francisco.

The purpose of this study was to describe the perceived health of the homeless, and to measure the effect of time homeless on perceived health status, after controlling for sociodemographic characteristics and health conditions. The design was cross-sectional; the population was a representative sample of homeless in San Francisco, interviewed on health issues. Analysis of predictors of poor or fair health status was by logistic regression. In this sample of 2780 persons, 37.4% reported that their health status was poor or fair as compared to good or excellent. Reporting poor or fair health status was significantly associated with time homeless, after controlling for sociodemographic variables and health problems including results from screening for HIV and TB (OR = 1.49, 95% CI 1.24-1.79). Comparisons with data from the National Health Interview Survey (NHIS) showed poorer health status among the homeless persons in this study. Standardized morbidity ratios were highest for asthma; there was twice the number of homeless persons reporting asthma, in younger as well as older adults, as would be expected using NHIS rates. There was also an excess of arthritis, high blood pressure and diabetes in those age 18-44 as compared to adults in the Health Interview Survey. The time spent homeless remains associated with self-reported health status, after known contributors to poor health are controlled. Persons who have been homeless for longer periods of time may be the persons to whom health care interventions should be aimed.

Adult↗

PubMed1997

BHRF1, a viral homologue of the Bcl-2 oncogene, is conserved at both the sequence and functional level in different Epstein-Barr virus isolates.

BHRF 1, a component of the restricted early antigen (EA) complex of the Epstein-Barr virus (EBV) lytic cycle, encodes a 17 kDa putative transmembrane protein with both sequence and functional homology to the Bcl-2 proto-oncogene. To determine whether there was any sequence variation over the BHRF1 open reading frame (ORF), 15 EBV isolates from different geographical regions and from both healthy donors and patients with EBV-associated diseases were sequenced. A small number of base changes which resulted in amino acid substitutions in the BHRF1 protein were found relative to the prototype B95.8 EBV sequence and these were predominantly clustered near the amino terminus of the BHRF1 protein outside conserved domains identified in the Bcl-2 homologues. In transient transfection assays none of the mutations in the BHRF1 ORF from eight different EBV isolates had a significant effect on BHRF1 protein localization compared to the B95.8 BHRF1 protein. However, transient expression of the adenovirus 12 19K protein or Bcl-2 resulted in localization patterns distinct from that observed with BHRF1 protein. Whilst all eight EBV isolates and E1B-19K gave comparable levels of protection to the DNA-damaging agent cis-platin, Bcl-2 did not afford significant protection. Thus, despite several amino acid changes in the BHRF1 ORF of some of the EBV isolates studied, the ability of the protein to protect against cis-platin induced apoptosis is conserved. The highly conserved nature of BHRF1 amongst different EBV isolates at both the sequence and functional level supports the proposed important role of BHRF1 in delaying cell death, thereby maximizing the production of progeny virus and facilitating the establishment of virus persistence.

Cloning, Molecular↗

PubMed1997

Are outcome data regarding the survivors of neonatal care available from routine sources?

AIM: To determine whether existing information and surveillance systems can be used to provide follow up data on groups of infants at increased risk of disability--for example, the survivors of neonatal intensive care. METHODS: A survey was made of maternity, neonatal, and community child health information systems and surveillance programmes in the Trent Regional Health Authority. Children known to have received neonatal intensive care in Trent between 1 August 1992 and 31 July 1993, and a random sample of normal children in two health districts (data quality check) were included. A data linkage study was made to determine whether follow up information about a random sample of infants, known to be at increased risk of poor outcome, could be identified on community child health databases. Two widely accepted datasets (birth and 2 years) were used as standards for this exercise. The quality of data was audited. RESULTS: All clinical items of the birth minimum dataset were routinely recorded by at least one agency in each health district in Trent. Of the descriptive items, only the mother's age on leaving full time education was not collected. At 2 years, all clinical items were collected as part of the routine surveillance programme, but data were recorded using a system which severely limited interpretation. Data quality, in terms of the number of errors introduced at data entry, was very good with only 1.1% of the check items (4/368) incorrectly recorded. Only two districts had organised electronic transfer of data between maternity, neonatal, and community child health systems. The mother's NHS number, although available, was not routinely recorded by any system. The NHS number of the infant was routinely collected by six out of 12 community paediatric services. Data linkage was attempted in six districts with appropriate community child health databases. Just over 70% of the intensive care sample was successfully linked with follow up information on child health systems. CONCLUSIONS: The existing programmes for routine child surveillance could provide outcome data for high risk groups of infants, such as the survivors of neonatal intensive care. However, the present coding system used for data entry is inadequate. Furthermore, rates of identification, without the use of a unique identifier (NHS number) for each subject, are currently insufficient for monitoring health status in later life.

Child Health Services↗

PubMed1997

An evaluation of the utility of the Home Health Care Classification for categorizing patient problems and nursing interventions from the hospital setting.

The purpose of this study is to evaluate the utility of the Home Health Care Classification for categorizing patient problems and nursing interventions from the hospital setting. The data set comprised 5,844 problem terms and 20,055 interventions terms. All terms could be categorized using the Nursing Components and Major Categories for Nursing Diagnoses and Interventions. A total of 1,767 (30.2%) patients problem terms could be placed into Major Nursing Diagnosis categories, but not subcategories even though there were subcategories related to the major category. All intervention terms whether they were classified at the Intervention Category or Subcategory could be coded according to Type of Nursing Action. These findings demonstrate that the Home Health Care Classification, at the level of Nursing Components and Major Categories, was domain complete for the data set. The fact that not all terms could be classified according to the existing subcategories suggests some areas for future development, but is also a reflection of the level of detail expressed in the data set itself. The results suggest that the Home Care Classification will be adequate and appropriate for categorizing problems and interventions across setting for the next phases of the research project.

AIDS-Related Opportunistic Infections↗

PubMed1996