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Biomedical subjects

M Cole

Publications and source records attributed to M Cole.

At least 163 records · Page 9Linked to original sources

Alveolar-cell carcinoma: a problem in sputum cytodiagnosis.

Cytology and histology are correlated in a series of 22 cases chosen to illustrate the differential diagnosis between clusters of benign bronchial or bronchiolar cells seen in sputum, and those of alveolar cell carcinoma or adenocarcinoma with alveolar spread. Alveolar-cell carcinoma is characterised by clusters of small epithelial cells in spherical or irregular formations, none showing enough polarity to distinguish a smooth or palisaded surface. The appearances are most distinctive if vacuolation is absent. The diagnosis cannot, however, be confidently made in all cases from morphological features of cells in sputum.

Adenocarcinoma↗

Cytological sampling at fibreoptic bronchoscopy: comparison of catheter aspirates and brush biopsies.

A prospective study was undertaken to compare bronchial brushings with dry catheter aspiration for the cytological diagnosis of lung cancer at fibreoptic bronchoscopy. Duplicate samples taken by aspirate and brush were obtained at 103 consecutive routine bronchoscopies. Aspirate and brush samples were reported on separately by two cytologists. At the end of the study a 30% sample, including the 19 cases with different findings by the two methods, were subjected to a blind crossover review, and then an open review. Forceps biopsy specimens for routine histological assessment were taken in 94 cases (92%). Ninety-eight of 103 (95%) aspirates and 99 of 103 (96%) brush specimens were technically satisfactory. Carcinoma was diagnosed at bronchoscopy on cytological or histological evidence or both in 57 cases. Fifty-five of these tumours (96%) were recognised by either the aspirate or the brush method, 52 (91%) by brush, and 50 (88%) by aspirate. Thirty-four cases (60%) could be diagnosed from histological specimens. The order of cytological sampling did not systematically affect yield. It is concluded that fine-catheter aspirates, permitting smears to be prepared in the laboratory, are a satisfactory alternative to brush smears for the cytological diagnosis of lung cancer at bronchoscopy. The routine use of both techniques at bronchoscopy will increase diagnostic yield by about 5%. Duplicate sampling may be especially useful in obtaining diagnostic material from upper-lobe or apical-segment tumours.

Biopsy↗

Biochemistry and action of clavulanic acid.

The destruction of amoxycillin by beta-lactamase action represents an important mechanism of bacterial resistance to the drug. Data is presented to illustrate that clavulanic acid used in the form of its potassium salt inhibits the amoxycillin destroying action of many different types of beta-lactamase for example: the staphylococcal enzyme, the clinically important plasmid mediated enzymes of the TEM, SHV, OXA and PSE types and the chromosomally controlled enzymes produced by Proteus mirabilis and Klebsiella pneumoniae. The mechanisms by which clavulanic acid inhibits beta-lactamases and potentiates the antibacterial action of amoxycillin are discussed.

Amoxicillin↗

Leukotrienes C and D induce bronchoconstriction in man.

Pulmonary responses to aerosols of synthetic leukotrienes C and D were examined in two normal volunteers. The leukotrienes were equipotent and equieffective in producing moderate bronchoconstriction accompanied by coughing. Changes in FEV1 were slight, but changes in expiratory flow at low lung volumes were more notable. FPL 55712 abolished the cough response and partially inhibited the bronchoconstriction.

Adult↗

An evaluation of the vitalograph pulmonary monitor.

The Vitalograph pulmonary monitor has recently been altered by the manufactures to read in litres per minute. In 200 pairs of measurements comparing the monitor to the Wright peak flow meter (PFM) the mean difference between the instrument was 0.57 litres/min and there was a strong positive correlation (r = 0.92). The mean within subject coefficient of variation was 5.8% (range 2.6% to 10.7%). There was a statistical difference (P less than 0.05) in measurements obtained with different monitors but in practical terms this difference was small. The monitor is pocket-sized and light and is therefore suitable for following changes in peak expiratory flow away from the physiology laboratory.

Evaluation Studies as Topic↗

BRL 17421, a novel beta-lactam antibiotic, highly resistant to beta-lactamases, giving high and prolonged serum levels in humans.

BRL 17421 is a new semisynthetic beta-lactam antibiotic with an unusual spectrum of antibacterial activity. The compound exhibits exceptional stability to a wide range of bacterial beta-lactamases and is active against the majority of Enterobacteriaceae, including strains highly resistant to many of the penicillins and cephalosporins currently available. Among the clinical isolates of Enterobacteriaceae tested, the frequency of strains resistant to BRL 17421 was found to be low, and there was a slow rate of emergence of resistance during in vitro studies. BRL 17421 was highly active against Haemophilus influenzae and Neisseria gonorrhoeae, including beta-lactamase-producing strains. The compound was markedly less active against Pseudomonas aeruginosa and Bacteroides fragilis than against the Enterobacteriaceae. Against the gram-positive bacteria, BRL 17421 showed a very low level of activity. BRL 17421 was found to be 85% bound to human serum, and the antibacterial activity was diminished two- to fourfold in the presence of human serum. Against experimental infections in mice, the activity of BRL 17421 reflected the properties observed in vitro. Studies in human volunteers showed unusually high and prolonged serum concentrations of the compound after parenteral dosage, with a serum half-life of about 5 h, and approximately 85% of the dose was recovered unchanged in the urine. BRL 17421 was poorly absorbed after oral administration. The compound was well tolerated after intramuscular and intravenous administration in volunteers, with no adverse side effects.

Animals↗

Intrapancreatic common bile duct compression causing jaundice in an adult with cystic fibrosis.

A 29-yr-old man with cystic fibrosis had a 4-yr history of recurrent episodes of obstructive jaundice. Endoscopic retrograde cholangiography revealed a common bile duct smoothly narrowed in its intrapancreatic portion, with dilatation above. A choledochojejunostomy was performed, but the patient died of septic complications. At autopsy, extensive pancreatic fibrosis caused compression of the distal bile duct in a manner which is analogous to that seen in chronic pancreatitis. This complication of cystic fibrosis, not previously reported, may become more prevalent as more patients with cystic fibrosis are living into adulthood.

Adult↗

'Beta-lactams' as beta-lactamase inhibitors.

The application of inhibitors to block the beta-lactamase destruction of penicillins and cephalosporins by resistant bacteria is a potentially useful way of improving the efficacy of established compounds. Certain semi-synthetic penicillins and cephalosporins have been found to be competitive inhibitors of selected beta-lactamases but an examination of streptomycete culture fluids has revealed two new types of beta-lactam compound: clavulanic acid, which is a progressive inactivator of a wide range of beta-lactamases, and the olivanic acids, which are both broad-spectrum antibiotics and potent beta-lactamase inhibitors. Penicillanic acid sulphone and 6-beta-bromopenicillanic acid have been shown to be significant inhibitors of beta-lactamase. The chemotherapeutic application of these compounds is discussed.

Anti-Bacterial Agents↗

Amantadine in senile dementia: electroencephalographic and clinical effects.

Nineteen patients with senile brain disease (including 2 with parkinsonian symptoms) were treated with amantadine in an oral dosage of 200--300 mg daily. Seven showed definite clinical benefits such as increased alertness and decreased agitation, and 2 others showed slight benefits. However, in only one instance was the benefit maintained without complications. Toxic effects such as overactivity, anxiety and visual hallucinations were observed in 8 patients. Withdrawal effects (e.g., lethargy and staggering) occurred when amantadine was discontinued. The electroencephalograms (EEGs) of all 19 patients showed a frequency increase, chiefly of occipital alpha activity, and sometimes a return to normal, irrespective of clinical changes. Toxic side effects were associated with particularly prominent EEG acceleration. In 10 of the 19 patients, the clinical changes were further validated by by additional psychologic assessments. Although the value of amantadine is limited when given in this way to patients with senile brain disease, it seems important to observe its effects in drug combinations aimed at correction of neurotransmitter imbalances.

Administration, Oral↗

Olivanic acids, a family of beta-lactam antibiotics with beta-lactamase inhibitory properties produced by Streptomyces species. I. Detection, properties and fermentation studies.

The screening of soil actinomyces for beta-lactamase inhibitors is described. Using a plate test a number of strains of Streptomyces were found to produce beta-lactamase inhibitory activity designated olivanic acid complex. Factors affecting the production of this complex by Streptomyces olivaceus ATCC 21379 are reported. The complex showed antibacterial activity and also inhibited a number of different types of beta-lactamase in a progressive manner. Certain ampicillin-resistant bacteria are rendered sensitive to ampicillin in the presence of olivanic acid complex at a concentration which alone did not inhibit growth.

Anti-Bacterial Agents↗

Efferent projections of the subthalamic nucleus: an autoradiographic study in monkey and cat.

The efferent projections of the subthalamic nucleus were studied with the autoradiographic tracing technique in Rhesus monkey and cat. From the data it appears that the major efferent projections of the nucleus are to the pallidal complex and the substantia nigra. In both monkey and cat, the projection to the pallidal complex is truly massive and is directed at both pallidal segments. The projection field includes an infracommissural part of the pallidal complex bordering on the substantia innominata. In the monkey the termination in the pallidal complex is organized in several characteristic bands oriented parallel to the medullary laminae. The subthalamo-pallidal projection in monkey further appears to be topographically organized. The projections to the substantia nigra is prominent in both cat and monkey though not as massive as that to the pallidal complex. The distribution of termination in the substantia nigra favors the more ventral strata near the cerebral peduncle. In the monkey the terminal distribution appears to avoid regions of the substantia nigra containing pigmented neurons and it is suggested that the subthalamo-nigral pathway may prefer non-dopaminergic neurons. In addition to the above major projections, sparse projections were noted to the thalamic nuclei ventralis lateralis and ventralis anterior, to the putamen, and to the mesencephalic nucleus tegmenti pedunculopontinus, pars compacta. The findings are discussed.

Animals↗