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Biomedical subjects

J A Bell

Publications and source records attributed to J A Bell.

At least 109 records · Page 6Linked to original sources
PubMed1990

A domestic ferret model of immunity to Campylobacter jejuni-induced enteric disease.

Oral or intravenous inoculation of previously unexposed juvenile and adult ferrets with Campylobacter jejuni uniformly resulted in intestinal colonization lasting 2 to 12 days. Disease varied from mild to moderate diarrhea, which resolved in 2 to 3 days. Orally infected animals developed agglutinin titers of 8 to 256 within 3 weeks, while those infected intravenously developed titers of 256 to 2,048. Ferrets which had recovered from campylobacteriosis all developed high titers of agglutinating and bacterial antibodies but were readily colonized by subsequent oral inoculation with the same strain of C. jejuni. Orally infected ferret kits 3 to 6 weeks of age exhibited the same general pattern of infection and disease as adults, but diarrhea was somewhat more severe. Kits resolved their diarrhea in 1 to 6 days and developed agglutinin titers in serum of 16 to 32 within 3 weeks. A series of five oral or rectal inoculations of kits during the 5- to 9-week age interval resulted in progressively shorter clearance times and eventual strain-specific resistance against infection, as well as disease. Gnotobiotic adults showed the same pattern of strain-specific accelerated clearance and resistance to disease. Kits born to immune dams with high levels of whey antibodies had passively acquired serum agglutinin titers of 256 to 2,048. These kits showed no resistance to colonization with the homologous strain of C. jejuni but were completely refractory to diarrhea. These observations suggest that (i) some form(s) of specific immunity, rather than factors relating solely to age or normal flora, is responsible for resistance to C. jejuni colonization and disease production and (ii) humoral immunity at a level that does not prevent colonization can protect against enteric disease caused by this organism.

Administration, Oral↗
PubMed1990

Expression of epidermal growth factor receptor in breast carcinoma.

A series of 90 patients with primary operable breast cancer and with up to 36 months of follow up were investigated for expression of epidermal growth factor receptor (EGFR) in their tumours by immunocytochemical staining with the monoclonal antibody EGFR 1. Tumour samples were snap frozen in liquid nitrogen immediately after resection and subsequently stained using a standard indirect immunocytochemical method. Tumour staining was assessed by two observers and scored on a four point scale (0-3). Thirteen (14%) tumours showed positive immunoreactivity. A strong correlation between distinct EGFR expression and short disease free interval was observed. Significant correlations were also shown with oestrogen and progesterone receptor expression and tumour nuclear size. No significant association was found with tumour size, lymph node stage, and histological grade. The association with disease free interval remained significant in multivariate analysis.

Antibodies, Monoclonal↗
PubMed1990

The electrocardiogram in general practice: its use and its interpretation.

General practitioners in one health district were surveyed by postal questionnaire (including 15 sample electrocardiogram tracings) to assess their usage and competence in interpretation of the electrocardiogram. A response rate of 60% was achieved, of whom 40% said they used the electrocardiogram at least monthly and 43% used it 'always' or 'usually' in patients with suspected myocardial infarction at home. Overall competence in recognizing a variety of abnormalities was felt to be good. Recent qualification, the possession of a higher qualification (MRCP/MRCGP) and frequency of usage were associated with better performance. Even so, unequivocal acute myocardial infarction was misdiagnosed by 20% of respondents. These findings have implications for the provision of electrocardiographic services in primary care and the management of patients in the home with suspected myocardial infarction, particularly with the advent of thrombolytic therapy.

Clinical Competence↗
PubMed1990

Reassessment of two apparent deletions of chromosome 16p to an ins(11;16) and a t(1;16) by chromosome painting.

Two apparent deletions of the short arm of chromosome 16 were studied by in situ hybridisation using biotinylated DNA from a chromosome 16 specific cosmid library (chromosome painting). One abnormality was delineated as a t(1;16)(p36;p12) and the other as a ins(11;16)(q13;p13.13p13.3). Apparently unbalanced de novo abnormalities detected by classical cytogenetic procedures should be interpreted with caution. In situ hybridization using DNA from chromosome specific libraries provides the appropriate technology to delineate such abnormalities.

Adult↗
PubMed1990

Congenital double elevator palsy in identical twins.

A left-sided double elevator palsy in identical twins born prematurely is presented, the first such report in twins. The aetiology of this condition is considered, and given the preservation of Bell's phenomenon and the absence of hypotropia in the primary position, the possibility that this may represent a supranuclear defect is discussed.

Diseases in Twins↗
PubMed1990

Postmyelographic abducent nerve palsy in association with the contrast agent iopamidol.

Lateral rectus palsy is an uncommon event following contrast myelography. We report such a case, which fortunately proved to be transient, and speculate on its aetiology in terms of the anatomy of the sixth cranial nerve and the possible toxic effects of the contrast agent Iopamidol (Isovue; ER Squibb and Sons, Princeton, New Jersey, USA; Niopam, E Merk, U.K.).

Abducens Nerve↗
PubMed1990

Derivation of gnotobiotic ferrets: perinatal diet and hand-rearing requirements.

A procedure is described which has resulted in successful gnotobiotic derivation of the domestic ferret. The most critical element of this hand-rearing procedure was found to be diet, with ferret milk being required for at least the first 7 days. Puppy milk replacer was phased in during the next 10 days, and enriched cow's milk sufficed thereafter. Around-the-clock sip-feeding with fire-polished Pasteur pipettes was necessary at intervals gradually increasing from 1 to 1.5 hours at birth to 3 hours by day 21. Temperature regulation was accomplished with an electric heating pad placed eccentrically under towel bedding to provide a 30 degrees-40 degrees C gradient, along which the kits positioned themselves to their own comfort. Techniques are described for minimizing fatalities due to dehydration, milk-aspiration pneumonia, underfeeding, overfeeding, gut stasis and obstipation. Internal hemorrhage, the greatest single cause of mortality in this study, manifested at day 13 and involved all kits by day 17. Despite immediate vitamin K1 dietary supplementation, five of the seven remaining kits died of hemorrhage by day 19. Around day 50, the two surviving kits were weaned from milk to dry commercial cat and ferret diets supplemented with vitamins K, C, A, D, E and B-complex and were reared to adulthood on this diet.

Animal Nutritional Physiological Phenomena↗
PubMed1990

Reproductive failure in mink and ferrets after intravenous or oral inoculation of Campylobacter jejuni.

Four pregnant mink and seven pregnant ferrets, including five with previous exposure and specific antibody, were injected intravenously with 10(8)-10(10) colony-forming units of Campylobacter jejuni. All 11 pregnancies failed 1-16 days after infection, with results ranging from fetal resorption to expulsion of dead or premature living kits. In every case, uterine contents (placenta, uterine fluid and/or kits) were culture-positive for C. jejuni. Three pregnant mink and nine pregnant ferrets, including four with previous exposure and antibody, were fed 10(9)-10(11) C. jejuni. Two of the mink aborted; kits of all three were culture-positive, but those of one female survived. Seven of the nine ferrets aborted, with two having culture-positive uterine contents. None of 28 uninfected ferret control pregnancies ended in abortion. The most prominent histological feature observed was severe placentitis, which appears to be a more likely cause of Campylobacter-induced abortion than direct pathogenic effects on infected kits. These results suggest that infection of mink or ferrets with C. jejuni during pregnancy poses a serious risk of reproductive failure, even for previously exposed females.

Abortion, Veterinary↗
PubMed1989

Naloxone-induced facilitation of C-fiber reflexes is reduced by chronic morphine.

The effects of chronic morphine on endogenous opioid function were examined in feline spinal cord. Naloxone-induced facilitation (disinhibition) of the C-fiber reflex was used as a model to reflect endogenous opioid function. Facilitation was reduced 24 h after withdrawal of chronic morphine (14 days). Acute morphine failed to depress C-fiber reflexes in the abstinent cats, indicating tolerance. Thus, these results demonstrated that, after chronic morphine, spinal endogenous opioid function was reduced due to tolerance.

Animals↗
PubMed1989

The effectiveness of two disinfectants on denture base acrylic resin with an organic load.

This study compared the biocidal effectiveness of chlorine dioxide and 5.25% sodium hypochlorite (diluted 1:10) on acrylic resin strips inoculated with Staphylococcus aureus, Candida albicans, or Escherichia coli in the presence of an organic load. Sterile acrylic resin strips were immersed in a solution containing 10% horse serum and 10(5) to 10(7) organisms/ml for each type of organism, then disinfected in chlorine dioxide, sodium hypochlorite, or 0.9 sterile saline for 30 seconds or 1, 2, or 4 minutes. After disinfection, the strips were neutralized and incubated for 72 hours. The results showed a difference between the ability of chlorine dioxide and sodium hypochlorite to kill the test organisms on acrylic resin strips when organic matter is present. Chlorine dioxide achieved complete disinfection of all three organisms within 2 minutes. Sodium hypochlorite achieved complete disinfection of all three organisms within 4 minutes.

Bacteria↗
PubMed1989

Anxiety disorders in the elderly. An update on diagnosis and treatment.

Anxiety is a symptom complex with a differential diagnosis that has become increasingly specific in recent years. Elderly patients often present to their primary care physician with symptoms of anxiety rather than seek a mental health professional. Because presentation may be somewhat different in elderly patients than in young adults, careful consideration of the differential diagnosis is important to ensure the most effective treatment. Pharmacotherapy, behavioral therapy, and traditional psychotherapy are useful for these disorders.

Adjustment Disorders↗
PubMed1989

Childhood deaths in Down's syndrome. Survival curves and causes of death from a total population study in Queensland, Australia, 1976 to 1985.

Data have been obtained from a total population study of diagnosed Down's syndrome cases born in Queensland between 1976 and 1985. Survival curves show a survival rate to one year of 87.4% and no significant differences in such patterns over the two five year periods of the study. Survival curves comparing maternal age at birth, sex of the infant, and locality of birth also indicate that early death is unrelated to any of these factors. Congenital heart disease and respiratory infection are the most common causes of infant death.

Australia↗
PubMed1988

Increased glucose utilization in superficial layers of the rat spinal dorsal horn during precipitated morphine withdrawal.

The 2-deoxy-D-[1-14C]glucose method was used to map effects of morphine withdrawal on glucose utilization in the rat spinal cord. Naloxone (0.5 mg s.c.) given to morphinized rats (225 mg morphine over 7 days) produced a withdrawal syndrome, and increased glucose utilization in the superficial layers of the dorsal horn in the cervical and thoracic spinal cord. The findings are consistent with an increased input from small diameter primary afferent fibers during the morphine withdrawal syndrome.

Animals↗