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Biomedical subjects

M Anderson

Publications and source records attributed to M Anderson.

At least 361 records · Page 20Linked to original sources
PubMed1987

Invasive disease due to Streptococcus pneumoniae in an area with a high rate of relative penicillin resistance.

During 1984 we conducted a population-based survey of culture-confirmed invasive disease due to Streptococcus pneumoniae among persons who lived in the Oklahoma City, Oklahoma, metropolitan area (population, 846,000) through the 20 clinical laboratories in the area. There were 139 residents identified with invasive pneumococcal disease (11 with meningitis and 128 with other bacteremic infections), for an infection rate of 16.4 per 100,000 population (meningitis, 1.3 cases per 100,000; other bacteremias, 15.1 cases per 100,000). Cases peaked in January-May and December (75% of cases). Rates were highest among infants less than 12 months old (97 cases per 100,000) and persons greater than or equal to 80 years old (87 cases per 100,000). Seventeen (12.2%) of the pneumococcal isolates were relatively penicillin resistant. These isolates were most prevalent among elderly persons greater than or equal to 70 years old (six [17.6%] of 34) and young children 0-4 years old (7 [15.9%] of 44) compared with persons 5-69 years old (four [6.6%] of 61).

Adolescent↗
PubMed1987

SPECT gallium scanning for lymphoma and infection.

Thirty gallium scans, using currently acceptable dosage levels (5-6 mCi) and a conventional rotating gamma camera, were performed on 20 patients with lymphoma or infection. Compared to planar scans, SPECT increased sensitivity and lesion detection from 48% to 89% in lymphoma, and from 50% to 80% in infection. The predictive value of a negative site was 81% in lymphoma and 67% in infection. Gallium utility is markedly increased by SPECT imaging. A normal gallium SPECT scan is highly accurate in ruling out disease.

Adult↗
PubMed1987

Spectrum and mode of action of azithromycin (CP-62,993), a new 15-membered-ring macrolide with improved potency against gram-negative organisms.

The macrolide antibiotic azithromycin (CP-62,993; 9-deoxo-9a-methyl-9a-aza-9a-homoerythromycin A; also designated XZ-450 [Pliva Pharmaceuticals, Zagreb, Yugoslavia]) showed a significant improvement in potency against gram-negative organisms compared with erythromycin while retaining the classic erythromycin spectrum. It was up to four times more potent than erythromycin against Haemophilus influenzae and Neisseria gonorrhoeae and twofold more potent against Branhamella catarrhalis, Campylobacter species, and Legionella species. It had activity similar to that of erythromycin against Chlamydia spp. Azithromycin was significantly more potent versus many genera of the family Enterobacteriaceae; its MIC for 90% of strains of Escherichia, Salmonella, Shigella, and Yersinia was less than or equal to 4 micrograms/ml, compared with 16 to 128 micrograms/ml for erythromycin. Azithromycin inhibited the majority of gram-positive organisms at less than or equal to 1 micrograms/ml. It displayed cross-resistance to erythromycin-resistant Staphylococcus and Streptococcus isolates. It had moderate activity against Bacteroides fragilis and was comparable to erythromycin against other anaerobic species. Azithromycin also demonstrated improved bactericidal activity in comparison with erythromycin. The mechanism of action of azithromycin was similar to that of erythromycin since azithromycin competed effectively for [14C]erythromycin ribosomebinding sites.

Anti-Bacterial Agents↗
PubMed1987

Chiari II malformation: MR imaging evaluation.

The purpose of this study was to explore the value of high-detail MR imaging in the diagnosis of the Chiari II malformation. Twenty-four patients with known Chiari II malformation as diagnosed by CT scanning were evaluated with cranial MR scans. Two patients also had spine scans. The sagittal-plane images were the most informative, and abnormalities of the telencephalon, diencephalon, mesencephalon, rhomboencephalon, upper spinal cord, and mesencephalon were shown extremely well. We found MR to be an easy and accurate method for demonstrating the abnormalities of the Chiari II malformation, and it is our procedure of choice.

Adolescent↗
PubMed1987

Familial subependymomas.

A family of eleven siblings is presented, five of whom developed a brain tumour. Three siblings had a subependymoma, one had an ependymoma and in one case the tumour was unverified histologically. The significance of familial brain tumours is discussed.

Adolescent↗
PubMed1987

Structure-activity relationships of 6-(heterocyclyl)-methylene penam sulfones; a new class of beta-lactamase inhibitors.

6-(Heterocyclyl)methylene penam sulfones (1) are effective beta-lactamase inhibitors and potent ampicillin and cefazolin potentiators against both Gram-positive and Gram-negative beta-lactamase producing bacteria. Several of these analogs having a pi-deficient 2-heteroaryl substituent attached to the C6-methylene position showed better inhibitory activity than clavulanic acid, Ro 15-1903, 6 beta-bromopenicillanic acid, and sulbactam against a variety of beta-lactamases. The compounds were devoid of any antibacterial activity, but in combination with ampicillin or cefazolin, exhibited synergistic activity at least equal to clavulanic acid, Ro 15-1903, 6 beta-bromopenicillanic acid or sulbactam against beta-lactamase producing strains. Structure-activity relationships for a number of compounds are described. The structure-activity relationships can be rationalized by an enzyme inhibition mechanism which we have previously proposed on the basis of methanolysis of 6-(2-pyridyl)methylene penam sulfone (1a). Two synthetic routes to prepare compounds of structural type 1 via either a Wittig reaction or an aldol condensation are reported. beta-Lactamase inhibition and MIC data are presented.

Ampicillin↗
PubMed1987

Diltiazem and propranolol in mild to moderate essential hypertension as monotherapy or with hydrochlorothiazide.

We compared the safety and efficacy of diltiazem and propranolol, and examined demographic factors influencing responses to these agents. One hundred ninety-six patients with supine diastolic blood pressures of 95 to 114 mm Hg were treated with propranolol (80 to 240 mg twice a day) or a sustained-release preparation of diltiazem (60 to 180 mg twice a day) in a double-blind, randomized, parallel group protocol for 6 months. Hydrochlorothiazide was added for patients not achieving the treatment goal. Both agents produced nearly identical and highly significant (p less than 0.001) reductions in supine blood pressure. There were no significant differences at the end of the optional combination therapy phase, although additional reduction with hydrochlorothiazide was slightly greater in the propranolol group. Blood pressure responses in relation to age, gender, race, and smoking history showed that diltiazem produced greater changes in older subjects and women, whereas propranolol was less effective in blacks. However, these differences were not critical.

Adult↗
PubMed1986

"Glycated" osteocalcin in human and bovine bone. The effect of age.

Purified osteocalcin from cow and calf bone was analyzed for nonenzymatic glycosylation (glycation) by sodium [3H]borohydride reduction. Calf bone was found to be approximately 5% glycated, while bone from mature cows was 10% glycated. These results were confirmed by a second method which utilizes periodate oxidation followed by formaldehyde fluorescence. Osteocalcin in human bone was also found to be glycated. The content of glycated osteocalcin from the bones of 47 nondiabetic individuals, aged 0.6-97, was dependent upon age. The extent of glycation was lowest in children, was constant through the adult years, and increased linearly in bone taken from individuals aged 60-97. Glycated osteocalcin was purified by boronate affinity chromatography and subjected to one-step Edman degradation. It was established that the site of glycation was the amino-terminal tyrosine. Increases in the amount of glycated osteocalcin in the bones of older individuals may play a role in the pathogenesis of senile osteoporosis and in the osteopenia which may accompany diabetes mellitus.

Aging↗
PubMed1986

The ultrastructure and physiology of the tergotrochanteral depressor muscle of the housefly, Musca domestica.

The gross morphology, ultrastructure, and the physiological properties of the tergotrochanteral depressor muscle (TTM) of the housefly are described. Under transmission and scanning electron microscopy, the TTM is a highly modified multinucleated tubular muscle of the synchronous class of insect muscle. Mitochondria appear few in number (5% of muscle volume) but there is an extensive sarcoplasmic reticulum (20% of muscle volume). Two types of neuromuscular junctions were observed, but these junctions are considered functionally similar. Three neurons innervate the muscle, and when the muscle is orthodromically stimulated, three well-defined thresholds are observed. Under repeated stimulation, the TTM fatigues rapidly but recovers in a short time. The TTM has a long "length constant" of 132.1 micron, 7.3 microF/cm2 membrane capacity, and a specific resistance of 394 omega cm2. The tergotrochanteral or "jumping" muscle has a behaviorally unique function. It is used only in the jump response preparatory to flight. TTM development is believed to have coevolved with an associated giant neuron to optimize the escape behavior response (response time 2.5 msec) in the housefly. The muscle has become specialized and more massive to increase the jump response. The TTM appears to be adapted physiologically and ultrastructurally for fast response and short twitch duration times.

Animals↗
PubMed1986

Assessment of central dopaminergic function using plasma-free homovanillic acid after debrisoquin administration.

Central dopaminergic (DA) function in children and adults was assessed by monitoring plasma-free levels of the dopamine metabolite homovanillic acid (pHVA) before and after a single oral dose and chronic oral administration of debrisoquin. Debrisoquin inhibits peripheral metabolism of dopamine to HVA and does not cross the blood-brain barrier. By reducing peripheral formation of HVA through the use of debrisoquin, the remaining HVA in plasma more accurately reflects central DA activity. Debrisoquin administration resulted in marked reductions of pHVA in each of 12 patients studied. Eleven of the 12 subjects tolerated debrisoquin without physical or behavioral side effects. The debrisoquin administration method appears to be a safe and potentially valid technique for evaluating aspects of central dopaminergic function in children and adults.

Adolescent↗
PubMed1986

The diagnosis and management of tuberculosis in common hostel dwellers.

Edinburgh hostel dwellers have been regularly screened for pulmonary tuberculosis since 1957. Sixty-eight cases were notified during the 7 years 1976-1982: 42 (65%) were detected by 4687 hostel survey X-rays, and a further 26 presented with symptoms. Disease was more advanced in the symptomatic hostellers both by radiological and bacteriological criteria with twice as many being sputum smear positive (58% vs. 26%). Full clinical details were available for 65 of the 68. Four were diagnosed at post mortem examination and two had chemotherapy stopped because the disease was considered inactive. Of the remaining 59 eligible for treatment, 47 (80%) received a complete course of adequate chemotherapy; 16 as hospital in-patients, 26 first in hospital and then under out-patient supervision and five simply as supervised out-patients; none relapsed. Twelve (20%) of the 59 defaulted from supervision after a mean follow-up period of 2.4 months.

Ill-Housed Persons↗