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Biomedical subjects

C M Harris

Publications and source records attributed to C M Harris.

At least 199 records · Page 11Linked to original sources
PubMed1981

The magnitude of post-reinforcement EEG synchronization (PRS) in cats reflects learning ability.

Electrocortical alpha-like activity, termed post-reinforcement synchronization (PRS), observed during operantly behavior, was quantified in 25 cats and plotted against the number of training sessions required for each to learn to press a lever for milk reward. A significant correlation (r = 0.77; P less than 0.001) was found between PRS magnitude and learning ability. The time required for learning correlated with the amount of perseveration in partially reinforced, i.e. ineffective, behavioral modes.

Animals↗
PubMed1980

Spontaneous perforation of the colon.

We describe the clinical presentation and surgical and pathologic findings in seven cases of spontaneous perforation of the colon. The dominant categories found were (1) rupture, usually of the cecum, associated with paralytic ileus, and (2) an idiopathic variety, invariably at the sigmoid. Though the onset of cecal rupture in paralytic ileus is insidious and may be anticipated, that of the idiopathic is not. If the clinical triad of sudden urge to defecate, hematochezia, and peritonitis occurs in a previously asymptomatic individual, idiopathic colonic rupture should be ruled out. An abdominal roentgenogram showing free intraperitoneal air strongly confirms the diagnosis. Prompt surgical repair of the rupture usually leads to recovery.

Adult↗
PubMed1980

Preclinical teachers and preclinical students.

A survey in 1974 in Manchester University medical school of the preclinical teachers showed that they thought that the motives of students in studying medicine were not what they should have been. Medically qualified and non-medically qualified teachers agreed about the importance of nine suggested motives, but there were highly significant differences between the two groups about the motives they felt to be present in students. The non-medically qualified were very much more likely to see students as concerned with the financial and social rewards of medicine, and more likely to doubt students' desires to be professionally competeant or to help individuals. Some anecdotal evidence possibly throws light on these findings, which may have serious implications for teaching as non-medically qualified staff make up an increasing proportion of preclinical teachers.

Attitude of Health Personnel↗
PubMed1979

Structural investigation of the antibiotic ristomycin A. The amino acid constituents.

Hydrolysis of the O-methylated aglycone of ristomycin A by a mixture of KOH and NaBH4 yielded a mixture of aromatic amino acids which, after N-acetylation and O-methylation, were separated by chromatography on silica gel. Compounds III approximately VII were isolated and identified by pmr and mass spectroscopy. Compounds V approximately VII were also oxidatively degraded to the corresponding benzoate esters. Componds III and IV are derived from ristomycinic acid (I) and V from actinoidinic acid (II), both of which had been obtained in earlier acid hydrolyses of the antibiotic. Compounds VI and VII had not been detected previously nor glycine which was also found to be a product of base hydrolysis. It is postulated that the new products arise from bisdechlorovancomycinic acid (X). It is concluded that aglycoristomycin A comprises I, II and X which also constitute the aglycone of ristocetin A.

Amino Acids↗
PubMed1979

The surgical treatment of the carpal-tunnel syndrome correlated with preoperative nerve-conduction studies.

The diagnosis of carpal-tunnel syndrome was made clinically in 124 cases (101 patients) and in each instance it was confirmed by nerve-conduction studies. Surgery was carried out with a uniform technique. Retrospective analysis of the series suggests that nerve-conduction studies can be used as a prognostic factor. Those patients with motor abnormalities appeared to have a more favorable result than those with only sensory abnormalities. Neurolysis was found to be a valuable adjunct to the release of the volar carpal ligament. Preoperative duration of symptoms did not appear to significantly influence the results of the operation.

Adult↗
PubMed1976

Band-shape analysis and resolution of electronic spectra of pyridoxal phosphate and other 3-hydroxypyridine-4-aldehydes.

The electronic absorption spectra of individual ionic forms of pyridoxal phosphate and of a series of related aldehydes have been evaluated together with pKa values. Spectral resolution with lognormal curves has permitted the quantitative description of equilibria for hydration and tautomerization. Precise values of peak positions for both aldehyde and hydrate forms have been obtained. Measurements of temperature-induced changes in the spectra have provided additional information. Knowing the hydration ratios and stepwide acid dissociation constants, it is possible to evaluate microscopic acid dissociation constants for both the aldehyde and hydrate forms of the compounds.

Molecular Conformation↗
PubMed1976

Teaching the teachers.

This and the following two papers describe historically the development of courses for general practice teachers in Manchester from 1966. The first paper describes the early attempts to fashion an appropriate course, discusses the content of such courses and the methods used. The second and third papers then discuss a course on non-directive behavioural counselling as an educational tool and describe the evolution of a cycle of four courses, each dealing with separate aspects of teaching. The emphasis throughout is on person to person teaching, it being considered that this is the commonest teaching/learning situation in general practice. The second part of the first paper goes on to discuss the logistic needs for the preparation and maintenance of teachers in general practice.

Curriculum↗
PubMed1976

A teaching methods course in Manchester for general practitioner teachers.

A teaching-methods course for general practitioner teachers is described. It lasts for 20 days, split into four 5-day residential sections held at intervals of 6 months. The sections are respectively entitled person-to-person teaching, small group teaching, teaching behaviour, and a micro-training laboratory. They recur in a cycle. The approach in each section is that of experimental learning--necessarily, since an aim of the course is to enable the members to apply the same approach in their own teaching. The methods of three of the sections are given in some detail. The person-to-person teaching section, concerned mainly with the learning of counselling skills, is dealt with fully by Long et al. (1976), and is here presented very briefly. The limited evaluation and assessment procedure, and their results, are offered together with certain general conclusions.

Counseling↗
PubMed1976

A method of teaching counselling.

The major part of one section of a teaching-methods course for general practitioner teachers (Harris et al., 1976) was concerned with teaching counselling skills. This paper describes the methods used to do so, in the setting of a residential course lasting for only a few days. The functions and objectives of counselling are defined, and the counselling process is divided into six stages which are reflected in the organization of the teaching. Five specific skills required are isolated, to clarify the teaching and to permit assessment of the members' learning. Three roles in a counselling interview are described, and members work in trios where they experience each of these roles. The problems at which the members work have to be real and unresolved problems in their own lives. Some conclusions are offered, drawn from the writers' experience and from the evaluation and assessment techniques employed.

Counseling↗
PubMed1976

Heterotopic bone formation after total hip arthroplasty.

Heterotopic bone formation is a common complication of total hip arthroplasty. A certain degree of heterotopic bone formation occurs in about one-half of the patients in degrees ranging from very mild to moderate involvement. The patients do not necessarily have any clinical disability; only 2 per cent of the patients developed severe heterotopic bone radiographically, and unsatisfactory functional results. There is no sex predilection for heterotopic bone formation except that the condition appears more severe in females. All ages are equally affected. The underlying disease process in the hip does not influence the occurrence of heterotopic bone. The incidence was significantly greater in patients who developed postoperative hematomas, prolonged wound drainage, or superficial infection. When surgical exposure is difficult and retraction of soft tissue aand soft tissue damage takes place, the incidence is much greater. Patients who have undergone previous surgical procedures about the hip present a greater risk in regards to development of disabling heterotopic bone formation. The etiology of heterotopic bone formation is not known. The following steps should be taken to avoid or greatly minimize the development of heterotopic bone: meticulous exposure with most careful retraction, copious irrigation with antibiotic solution, debridement of devitalized tissue prior to closure, instillation of drainage tubes, intraoperative and postoperative antibiotics, and carefully controlled postoperative anticoagulation.

Arthroplasty↗
PubMed1975

Properties of 4-ethenyl and 4-ethynyl analogs of pyridoxal phosphate and their reactions with the apo form of asparatate aminotransferase.

The binding to apoaspartate aminotransferase of analogs of pyridoxal phosphate bearing vinyl, cis- and trans-methylvinyl, and ethynyl groups in place of the fomyl group of the coenzyme has been studied. Details of synthesis of the ethynyl compound are given. The absorption spectra of all of the compounds have been analyzed and pKa values have been determined. The positions of the absorption bands can be related to those of pyridoxine but with bathochromic shifts induced by the ethenyl and ethynyl groups. However, this shift is almost completely lacking for the cis-methylvinyl compound suggesting nonplanarity of the molecule. Binding of the analogs to the apoenzyme is accompanied by a strong bathochromic shift which, from a study of solvent effects on the free analogs, appears to indicate a hydrophobic environment on the enzyme. Nevertheless, the analogs are bound as dipolar ions exclusively. Binding is accompanied by a distinct perturbation of the protein spectrum in the aromatic region. An effect on the spectrum of 1 or more tryptophan residues is indicated. Bands of the bound analogs exhibit positive circular dichroism except for that of the 4-vinyl analog. The 4-ethynyl analog reacts in a more complex way, giving at least two successive products in addition to the initial complex. The final product is reducible by sodium borohydride, is released from the enzyme by boiling, and appears to have the properties of a Schiff base. We postulate that the addition of an amino group of the enzyme to the ethynyl group is followed by tautomeric rearrangement to a Schiff base in which the ring is in a p-quinonoid structure.

Animals↗