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Biomedical subjects

D Smith

Publications and source records attributed to D Smith.

At least 883 records · Page 49Linked to original sources
PubMed1989

The effect of prophylactic anti-asthma drugs on PAF-induced platelet accumulation in the thorax of the guinea pig.

Intravenous infusion of platelet activating factor (PAF) causes an accumulation of platelets within the thorax of the guinea pig that is accompanied by increased sensitivity of the airways to spasmogens. A crystal scintillation detector has been used for measurement of intrathoracic accumulation of 111Indium-labeled platelets during responses to PAF. PAF-antagonists inhibit development of airway hyperreactivity, do not diminish platelet accumulation in response to an intravenous infusion of PAF. It is therefore concluded that intrathoracic platelet accumulation per se is not the determinant of increased airway reactivity.

Airway Resistance↗
PubMed1989

Visceral leishmaniasis (kala azar) in a patient with AIDS.

A patient with HIV infection presented with multiple cutaneous Kaposi's sarcomata. Biopsy of one of these showed the presence of amastigotes within an otherwise typical Kaposi's sarcoma. Further investigations proved the patient to have visceral leishmaniasis (kala azar). Visceral leishmaniasis has been reported in HIV infection but it is rare and this presentation is unique. The patient made a good response to a prolonged course of treatment with sodium stibogluconate and allopurinol.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Construction of a linkage map of the human genome, and its application to mapping genetic diseases.

A powerful method for localizing the genes responsible for genetic diseases is to "mark" each chromosomal region so as to permit its inheritance to be tracked in families carrying the disease; the disease gene must lie in the same region as any marker with which it is co-inherited. Chromosomes can be efficiently marked in this way by using restriction fragment length polymorphisms (RFLPs). We describe the construction of a map of the human genome with over 550 RFLP markers, such that over 95% of the genome is detectably linked to one or more of these markers. This map will make possible efficient searches for genes underlying a variety of disorders, both simple and complex, and lead to the development of presymptomatic diagnostic tests for these diseases.

Base Sequence↗
PubMed1989

Failure of prediction of liver function test abnormalities with the urine urobilinogen and urine bilirubin assays.

A prospective observational study of 229 cases was conducted in a busy ambulatory care setting to evaluate the sensitivity, specificity, predictive values, and accuracy of spot urine urobilinogen and urine bilirubin assays as screening tests for serum liver function test (LFT) abnormalities. Both urine tests exhibited remarkably similar characteristics overall once they were adjusted to maximize accuracy and predictive values (occurring at a normal or abnormal "threshold," respectively, of 3.4 or 5.07 mumol/d for urobilinogen and 0 or 1+ for urine bilirubin). The percentage of cases correctly identified were 81% to 83% for serum bilirubin assays, 68% to 72% for other LFTs, but only 62% to 63% for screens for cases with at least one abnormal LFT finding. Poor sensitivities (47% to 49%) limited the detection of abnormal findings by the screen; both screens were reasonably specific (79% to 89%), but negative predictive values were suitable (89%) for serum bilirubin results only and were prohibitively lower (49% to 50%) in predicting all patients without LFT abnormalities. We conclude that spot urine urobilinogen and urine bilirubin determinations, although good screens for isolated serum bilirubin elevations, have unacceptable statistical properties as predictors of other LFT results due to a high proportion of false-negative results.

Bilirubin↗
PubMed1989

Ticarcillin/clavulanic acid versus clindamycin and gentamicin in the treatment of post-cesarean endometritis following antibiotic prophylaxis.

One hundred fifty-two women who received cefazolin prophylaxis and subsequently developed postpartum endometritis were randomized to treatment with either ticarcillin/clavulanic acid (75) or clindamycin-gentamicin (77). Bacteria isolated from the endometrium were predominantly facultative anaerobic bacteria. The ratio of facultative anaerobes to obligate anaerobes was 3:1. Nineteen percent of the women were bacteremic, with mycoplasma the organism most frequently isolated from venous blood specimens. Cure rates were similar for both groups: ticarcillin/clavulanic acid 85% and clindamycin-gentamicin 81%. The advantages of ticarcillin/clavulanic acid are an increased spectrum of activity against beta-lactamase-producing bacteria, less toxicity, and lower cost.

Adult↗
PubMed1989

Value of screening umbilical cord blood for hemoglobinopathy.

Foremost among the beneficial effects of screening umbilical cord blood is the optimized quality of care that can follow the immediate involvement of an infant with sickle cell disease and his or her family in an appropriate health care system. This is exemplified by the reduction in the case fatality rate of pneumococcal septicemia that has been achieved. Appropriate follow-up of screening also includes transmission of information about the diagnosis of a hemoglobinopathy trait or alpha-thalassemia to affected families and their physicians, with ready availability of education and counseling.

Anemia, Sickle Cell↗
PubMed1989

Transcervical uterine cultures with a new endometrial suction curette: a comparison of three sampling methods in postpartum endometritis.

The potential for cervicovaginal contamination has precluded direct sampling of the endometrial cavity and has led to the development of multi-lumen protected catheter systems, among other techniques. The extent of this presumed contamination was examined using three different techniques in 55 postpartum women with the diagnosis of endometritis. Each woman had the endometrium sampled with an unprotected cotton-tipped swab, a double-lumen catheter with brush, and a flexible endometrial suction curette. A statistically larger number of bacterial species was recovered with the cotton swab (2.4) than with the double-lumen catheter (1.3) or the suction curette (1.7) (P less than .001). A difference was also noted between the double-lumen catheter and the suction curette (P = .006); however, this represented less than one-third of a single bacterial species. The larger number of bacterial species recovered by the unprotected methods was found to result not from cervicovaginal contamination, as suspected, but from a significant increase in the recovery of bacteria commonly regarded as potential pathogens, such as Bacteroides bivius, Streptococcus faecalis, Proteus mirabilis, and Bacteroides melaninogenicus.

Dilatation and Curettage↗
PubMed1989

Asthma and chronic airflow limitation in the highlands of Papua New Guinea: low prevalence of asthma in the Asaro Valley.

The prevalence of asthma in the South Fore region of Papua New Guinea was found to be 7.3%, which is thought exceptionally high for highland areas in this country. To investigate the prevalence of asthma and of chronic airflow limitation in a different highland region with similar living conditions, adults and children from 7 villages in the Asaro Valley were interviewed. Questions were asked about smoking history and about past and present symptoms of cough, of shortness of breath, of chest tightness and of asthma. Of 743 adults interviewed, 206 underwent a clinical study with measurements of lung function, bronchial responsiveness and skin prick tests. Dust was collected from the floors and blankets of 36 houses for counts of house dust mites. We did not find any children with symptoms of asthma. Only 2 adults (0.3%) had symptoms consistent with asthma, and a further 6.2% had symptoms and/or lung function consistent with chronic airflow limitation. Most bronchial hyperresponsiveness was associated with asthma or with chronic airflow limitation. The prevalence of atopy was similar in the Asaro and South Fore populations, but the South Fore had higher house dust mite counts in blanket dust. The low prevalence of asthma in the Asaro Valley is unexplained in terms of factors normally associated with asthma. Because asthma in this area does not appear in childhood and only develops in a small proportion of adults, it may be of different aetiology to asthma in Caucasian populations.

Adult↗
PubMed1988

Inhibition of rat brain pyruvate dehydrogenase by thiamine analogs.

The effects of thiamine thiazolone (TT) and thiamine thiazolone pyrophosphate (TTPP) on the in vitro and in vivo inhibition of pyruvate dehydrogenase complex (PDHC) from rat cortex and hippocampus were characterized. TTPP decreased PDHC activity in vitro but had no effect in vivo following its direct chronic administration via osmotic mini-pumps into the brains of behaving rats. In contrast, TT had no direct effect in vitro following a differential centrifugation purification of the mitochondrial PDHC fraction, but decreased PDHC activity in vivo. Additional experiments demonstrated that the cytosolic fraction converted TT to TTPP which, in turn, inhibited PDHC in vitro. A mechanism is proposed to explain these effects that is consistent with a non-competitive inhibition of brain PDHC by TTPP.

Animals↗
PubMed1988

Candida and AIDS: evidence for protective antibody.

Clinical observation and animal models of candidosis suggest that, although T lymphocytes are important in preventing superficial candidosis, defence against systemic candidosis depends upon humoral immunity. An antibody response to the immunodominant 47 kD antigen of Candida albicans is invariably associated with recovery. The presence of this antibody in patients with chronic mucocutaneous candidosis and the acquired immunodeficiency syndrome (AIDS) could account for the rarity of disseminated candidal infection in these conditions. Polyclonal B cell activation may be responsible for the frequency with which this antibody is produced in AIDS. Antibody to the 47 kD antigen could be useful in the treatment and prevention of systemic candidosis, though not in the superficial candidosis of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

A pharmacological analysis of the rat spinal cord serotonin (5-HT) autoreceptor.

The pharmacological characteristics of the presynaptic 5-HT receptor associated with the modulation of 5-HT release were investigated in a preparation of rat spinal cord synaptosomes (nerve terminals) superfused with a Tris-buffered Krebs solution containing fluoxetine (1 microM). The 5-HT receptor agonists serotonin (1-100 nM), lysergic acid diethylamide (10 nM-1 microM) and the 5-HT1B receptor agonists 1-(m-trifluoromethylphenyl)piperazine (100 nM-1 microM) and 1-(m-chlorophenyl) piperazine (100 nM-3 microM) concentration dependently decreased [3H]5-HT release, while 8-hydroxy-2-(di-n-propylamino)tetralin, a selective 5-HT1A receptor agonist, was inactive. The actions of the effective agonists were reversed by quipazine, an antagonist with high affinity for 5-HT1B binding sites, but not by spiperone, a 5-HT1A receptor antagonist. Furthermore, mesulergine, a 5-HT1C receptor antagonist was ineffective in reversing the action of 5-HT on [3H]5-HT release. These data indicate that the rat spinal cord nerve terminal autoreceptor has characteristics similar to the 5-HT1B binding site.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1988

Clinical predictors of severe head trauma in children.

We reviewed the medical records of 55 patients who underwent a cranial computed tomographic (CT) scan for acute head trauma. The severity of head trauma was classified according to objective clinical findings as severe in 44 patients, moderate in three, and mild in eight. Thirty-seven patients (84%) with severe head trauma had a brain injury identified on CT scan. Six patients with severe head trauma had a Glasgow Coma Scale score of 12 or greater and an abnormal CT scan. All patients with mild or moderate head trauma had normal CT scans. Severe head trauma, as defined in this study, accurately identified all patients with abnormal CT scan findings. We conclude that a classification based on objective clinical findings accurately identifies the severity of head trauma. This is particularly important in evaluating patients with a Glasgow Coma Scale score of 12 or greater. A prospective study including larger numbers of patients is needed to further evaluate such a classification.

Adolescent↗