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Biomedical subjects

M J Morris

Publications and source records attributed to M J Morris.

At least 127 records · Page 7Linked to original sources
PubMed1978

Evaluation of a multitest system for identification of saccharolytic pseudomonads.

The API-20 Enteric Strip has been proposed to have the capacity to differentiate the nonfermentative gram-negative bacilli. This multitest strip serves as the basis of an evolving system, which first provided a Register, then a Selector, and more recently a computer Index. Twenty-three strains of Pseudomonas aeruginosa and P. putida, 21 of P. fluorescens, 27 of P. maltophilia, and 33 of P. cepacia were investigated by duplicate test runs to determine reproducibility. The results were then evaluated at each of the three stages to determine accuracy of identification and the effect of the system evolution on the identification rate. Seventy-one of the 127 pseudomonads gave reproducible results in the multitest strips. Approximately half of them were correctly grouped or speciated by the Register, whereas 80 to 83% were similarly identified by both the Selector and Index. Of the clinically important pseudomonads, 61 to 65% of P. aeruginosa and 93% of P. maltophilia strains were correctly speciated; neither P. putida nor P. fluorescens strains were speciated, although most were correctly grouped. P. cepacia was speciated by the Index with only 55 to 58% accuracy. Although the present stage of the evolving system offers improvement over the Register, further modifications are needed to eliminate identification problems and to increase speciation.

Bacteriological Techniques↗
PubMed1978

Effect of two cancer chemotherapeutic agents on the antibacterial activity of three antimicrobial agents.

Cancer chemotherapeutic agents and antibacterial antibiotics are often given concomitantly. Daunorubicin, cytosine arabinoside, and three antibiotics (gentamicin, amikacin, and ticarcillin) were tested individually and in combinations to determine their antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. These cytotoxic agents are commonly employed in the therapy of acute nonlymphocytic leukemia for remission induction therapy, and these antimicrobial agents are used in infection therapy. The maximum concentrations of the two cytotoxic drugs were chosen to be twice the known peak plasma levels of commonly employed dosage schedules. Neither of the cancer chemotherapeutic agents, alone or in combination, demonstrated bactericidal activity at the levels tested. However, in the presence of these agents, the antimicrobial activity of gentamicin and amikacin, although not that of ticarcillin, was depressed for 11 of 15 K. pneumoniae strains and 8 of 15 P. aeruginosa strains, but for none of the strains of E. coli. This level of decreased activity occasionally resulted in a minimal inhibitory concentration of the tested aminoglycoside well above the standard serum levels. Daunorubicin was more likely to antagonize gentamicin than was cytosine arabinoside.

Amikacin↗
PubMed1978

Action of cefoxitin and cefamandole on human neutrophil function.

Polymorphonuclear neutrophilic leukocyte chemotaxis was examined in vitro in the presence to two new antibiotics: cefamandole and cefoxitin. Results indicate that cefamandole inhibited neutrophil chemotaxis to a significant degree only at high antibiotic concentrations of 100 microgram/ml (P less than 0.01) and has no significant effect at normal serum therapeutic range. Cefoxitin was found to produce a 43% inhibition (P less than 0.01) of human in vivo neutrophil chemotaxis at antibiotic concentrations of 100 microgram/ml and have a minimal inhibitory effect (1 approximately 9%) at low concentrations (1 approximately 5 microgram/ml). Both cefamandole and cefoxitin had no significant effect on opsonophagocytosis.

Cefamandole↗
PubMed1977

Hepatic metastases from colorectal carcinoma: an analysis of survival rates and histopathology.

Out of 338 patients undergoing laparotomy and resection of a primary colorectal carcinoma, 49 (14-5%) were folnd to have liver metastases. The average age was 70 years. The median period of survival was 11-4 months. The histological grade of malignancy of the primary tumour did not appear to influence the survival rate. Compared with similar tumours in patients without hepatic metastases, the primary growth showed a significantly increased incidence of venous invasion, a higher grade of malignancy, and a more frequent origin from the right colon. When the local spread of the primary tumours was investigated it was found that one-third of them had not progressed beyond Stage Dukes A or B.

Adenocarcinoma↗
PubMed1977

HLA in asthma.

100 adult patients with asthma were typed for HLA. These patients were skin tested with a panel of allergens and divided into skin test positive (61) and skin test negative (39) patients. There was a decreased frequency of HLA-B12 in the negative skin test group (18%) compared to the skin test positive group (43%) and the controls (36%). A further subdivision of these patients into extrinsic asthma (positive skin tests and/or allergic history) and intrinsic asthma (negative skin tests and no allergic history) was made. There was an increased frequency in the extrinsic asthmatics of HLA-B8 (37 compared to 28% in normals) and a decreased frequency of B12 in the intrinsic asthmatics (13 compared to 36% in normals). 4 or 5 patients who had negative skin tests but gave a history of asthma following exposure to specific allergens, suggesting a type III immune complex asthma, were both A1 and B8.

Adolescent↗
PubMed1976

The value of prophylactic antibiotics in transurethral prostatic resection: a controlled trial, with observations on the origin of postoperative infection.

Prophylactic antibiotics significantly decrease the incidence of urinary tract infection following endoscopic prostate resection. They are ineffective in reducing the incidence of postoperative fevers, or in reducing the frequency of positive blood cultures during or after operation. A majority of prostate glands harbour colonies of potentially pathogenic organisms, and these are the commonest source of infection of the urinary tract following release by prostatic surgery.

Aged↗
PubMedDate not supplied

The effects of estrogen replacement therapy on airway function in postmenopausal, asthmatic women.

BACKGROUND: Data from multiple clinical, epidemiologic, and in vitro studies are conflicting regarding the effect of estrogen replacement therapy (ERT) on airway function in postmenopausal women with asthma. OBJECTIVE: To determine the impact of withdrawal of estrogen administration in postmenopausal, asthmatic women. METHODS: Twenty asthmatic women who were postmenopausal for at least 2 years and undergoing ERT were recruited for this prospective crossover study. Subjects continued taking baseline estrogen for 28 days, stopped taking estrogen for 28 days, and then resumed taking the medication for 14 days. Objective measurements were obtained by recording daily peak flows in the morning and evening and formal spirometry at days 14, 28, 42, 56, and 70. Compliance was measured by evaluating serum estradiol levels at days 28 and 56. Daily use of short-acting beta-agonist bronchodilators was also recorded. RESULTS: Differences in estradiol levels indicated compliance with the medication regimen. The combined day 14 and 28 (taking estrogen) mean percent predicted forced expiratory volume in 1 second (FEV(1)) was 77% compared with the combined day 42 and 56 (not taking estrogen) mean FEV(1) of 78% and the day 70 (taking estrogen again) FEV(1) of 76% (P>.05). Average peak flow measurements were 295.5 L/min for the duration of ERT, 293.9 L/min while not undergoing ERT, and 291.8 L/min when ERT was restarted for the final 2 weeks of the study (P>.05). Use of short-acting beta-agonist bronchodilators did not differ between study periods. CONCLUSION: These data indicate that neither the discontinuation nor reinitiation of ERT in postmenopausal, asthmatic women has any effect on objective measures of airway obstruction.

Asthma↗
PubMedDate not supplied

Midline B3 serotonin nerves in rat medulla are involved in hypotensive effect of methyldopa.

Previous experiments in this laboratory have shown that microinjection of methyldopa onto the ventrolateral cells of the B3 serotonin neurons in the medulla elicits a hypotensive response mediated by a projection descending into the spinal cord. The present experiments were designed to investigate the role of the midline cells of the B3 serotonin neurons in the medulla, coinciding with the raphe magnus. In spontaneously hypertensive, stroke-prone rats, microinjection of methyldopa into the area of the midline B3 serotonin cell group in the ventral medulla caused a potent hypotension of 30-40 mm Hg, which was maximal 2-3 h after administration and was abolished by the serotonin neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) injected intracerebroventricularly. However, intraspinal injection of 5,7-DHT to produce a more selective lesion of only descending serotonin projections in the spinal cord did not affect this hypotension. Further, 5,7-DHT lesion of serotonin nerves travelling in the median forebrain bundle, one of the main ascending pathways from the B3 serotonin cells, did not affect the fall in blood pressure associated with a midline B3 serotonin methyldopa injection. It is concluded therefore that, unlike the ventrolateral B3 cells which mediate a methyldopa-induced hypotension via descending projections, the midline serotonin B3 cells in the medulla contribute to the hypotensive action of methyldopa, either by way of an ascending projection which does not pass through the median forebrain bundle, or through a projection restricted to the caudal brainstem.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

Plasma catecholamines and neuropeptide-Y as indices of sympathetic nerve activity in normotensive and stroke-prone spontaneously hypertensive rats.

The suitability of plasma catecholamines (CAs) and neuropeptide-Y (NPY) as biochemical indices of sympathetic nerve activity (SNA) has been investigated, and these parameters have been compared between adult normotensive (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Plasma norepinephrine (NE), epinephrine (E) and NPY were measured in venous and arterial blood samples taken from conscious, unrestrained rats. Under resting conditions, both CAs were significantly higher in SHRSP than in WKY; plasma E in particular was raised threefold. SHRSP had higher plasma levels of NPY in arterial blood but not in venous blood. Acute hydralazine-induced hypotension caused a slight rise in NPY and striking increases of CAs, which were accentuated in SHRSP. Ganglion blockade with pentolinium reversed these increases but the differences in basal plasma CA levels between strains still persisted. Barbiturate anaesthesia had little effect on plasma levels of NPY or NE, but plasma E levels were depressed, particularly in SHRSP, so that the strain difference in plasma E taken from venous blood was no longer apparent. The results indicate that plasma levels of CAs but not NPY are useful indices of SNA in conscious rats. Comparisons between WKY and SHRSP after drug treatment demonstrate a major contribution by the adrenal medulla to plasma CA levels in SHRSP which, under resting conditions, may not be sympathetically evoked.

Anesthesia↗