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Biomedical subjects

D L Crombie

Publications and source records attributed to D L Crombie.

12 recordsLinked to original sources
PubMed1992

Acute effects of topical methyl tert-butyl ether or ethyl propionate on gallbladder histology in animals: a comparison of two solvents for contact dissolution of cholesterol gallstones.

Experiments were performed in anesthetized rabbits and piglets to assess gallbladder mucosal injury during irrigation with methyl tert-butyl ether, a C5 ether, or ethyl propionate, a C5 ester--two organic solvents used in the contact dissolution of cholesterol gallstones. In 44 New Zealand White rabbits, the gallbladder was exposed to individual solvents or saline solution through a transhepatic catheter for 2 hr. Gallbladders were then harvested and fixed immediately or after a recovery period of 1, 4 or 8 days. Tissue sections were examined under light microscopy, and severity of injury was graded with predefined criteria by two pathologists blinded to the animals' treatment regimens. Histological assessment showed severe mucosal injury such as necrosis of the cells at the villus tips immediately after 2 hr of exposure to either solvent. After 4 days, injury had decreased significantly; after 8 days, complete mucosal healing had taken place. A similar study was performed in 32 piglets. Solvent or saline solution was oscillated in and out of the gallbladders of these piglets with a computer-controlled syringe pump at a pressure less than the leakage pressure of the gallbladder. Histological assessment was performed on tissue samples obtained immediately after the procedure or 8 days later. Both solvents caused severe mucosal injury; however, after 8 days complete mucosal healing had occurred, so that gallbladders exposed to solvent were indistinguishable from gallbladders exposed to saline solution, which was used as control. We conclude that both methyl tert-butyl ether and ethyl propionate cause moderate to severe epithelial injury but that the gallbladder epithelium regenerates within a few days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The problem of diagnostic variability in general practice.

STUDY OBJECTIVE: The aim was to examine the scale, source, and relevance of variation between general practices in respect of the rates with which patients consulted with illnesses falling in each of several diagnostic groups. DESIGN: This study involved a general practice morbidity survey conducted over two years, 1970-72. All patients who consulted their general practitioners were identified and the number of these who consulted with diagnoses attributable to each of the 18 main chapters of the International classification of diseases were counted. Patients who consulted for more than one diagnosis within a chapter were counted once only; those who consulted for one or more diagnoses in each of several chapters were counted once for each chapter. SETTING: This was a national survey involving general practitioners in England and Wales. SUBJECTS: The study involved 214,524 patients from 53 selected general practices (115 doctors) who were registered with their general practitioners for the whole of the year 1970-71 and for whom their morbidity data had been linked with their social data from the 1971 census. MEASUREMENTS AND MAIN RESULTS: Using the numbers of patients on the practice lists as denominators, practice patient consulting rates (PPCR) were calculated for each practice and for each ICD chapter. Variability in chapter PPCR was examined by calculating coefficients of variation and, after allowance for random variation, coefficients of residual variation. There were large interpractice (doctor) variations in all chapter rates. These variations were only marginally attributable to: chance; different age, sex and social class mixes of practice populations; geographical locations; and practice organisation. The rates were, however, consistent from one year to the next for any one practice. Approximately half of the interpractice (doctor) diagnostic variability was associated with overall patient consulting behaviour. When the effects of this behaviour were discounted, any major residual diagnostic variability was confined largely to ICD chapters I-V, XVI, and XVII, ie, those chapters where aetiology forms the basis of classification. CONCLUSION: Variations in recorded diagnostic rates are mainly due to the consistent but idiosyncratic and selective exclusion by practitioners of some components from the total set which often coexist in a new diagnosis. Because of the scale of interpractice diagnostic variability, the use of algorithms and information technology is largely precluded from outcome studies, auditing procedures, and studies of practice work loads in general. However, (1) the consistency of any individual doctor's pattern of diagnostic recording from one year to another permits studies of trends; and (2) given a reasonable number of recording practices, the population mean practice consulting rates can be estimated with sufficient accuracy for many epidemiological research and administrative uses.

Age Factors↗
PubMed1991

Changes in practice morbidity between the 1970 and 1981 national morbidity surveys.

The primary aim of the study was to evaluate practice differences in reported morbidity in the second and third national morbidity surveys (1970/71, 1981/82) and to discuss their cause. A secondary aim concerned the validation of trends identified from analysis of the data from the total populations in the practices. Altogether 19 practices participated in both surveys. Annual prevalences (that is, the number of patients attending the general practitioner with a condition per 1000 persons at risk) were examined for: all conditions; each of three categories of seriousness of disease; diseases aggregated by chapter of the International classification of diseases; and each of 130 rubrics of the disease classification. Annual prevalence for 'all conditions' was approximately the same for males in both surveys, whereas for females there was an increase. In both sexes, annual prevalence for 'serious conditions' increased slightly and for 'trivial conditions' increased substantially. For 'intermediate conditions', there was a modest decrease in males. In the analysis at ICD chapter level, substantial increases in prevalence occurred in infectious diseases, nervous system diseases, circulatory diseases, genitourinary diseases, musculoskeletal diseases, symptoms, signs and ill-defined conditions, injuries and poisonings. Decreases were found in blood diseases, mental disorders and digestive diseases. Among 130 individual conditions examined, increased annual prevalence was found for mumps, fungal infections, hypothyroidism, diabetes, gout, senile dementia, angina, left heart failure, catarrh, hay fever and asthma, orchitis, acne, osteoarthritis and for some symptoms. Decreases were found for iron deficiency anaemia, anxiety state, refractive errors, haemorrhoids, chronic bronchitis, functional disorders of the stomach, carbuncle and skin infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1976

The nature of information used in making clinical decisions in general practice.

This preliminary study indicates that in general practice:(1) Acquisition of appropriate clinical information is more often than not dependent on prior information of a highly selected kind available economically only to a personal doctor.(2) The amount of previous information which could be stored outside the brains of a personal doctor and his patient is relatively enormous and almost unlimited.(3) But, the amount of this externally stored previous information which will ever be used, referred to, or be clinically useful is minimal.(4) Logic branching systems for obtaining this essential clinical information for each episode are of two kinds. There is first the system which is universally appropriate to all patients and all diseases as a whole, a field in which the computer is becoming pre-eminent, but which also has its limitations. Secondly there is the highly personalised system, constituted by the clinical dialogue of the patient and his personal doctor, the structure of which, at present, defies any simplification and which we abandon at our peril.(5) Continuing care by group-practice teams operating under one roof eliminates the need for fragmentation of primary clinical records.(6) A simple up-dated manually-prepared paper summary of clinical problems encountered and therapeutic activity taken, may well be the essential core of this shared record. This would be backed up by the ad hoc clinical records of each health care professional as accessible, second level archives, conforming to some simple, systematic and universally accepted structure (Bjorn and Cross, 1970).It would be of great interest to know whether or not the same conclusions would be drawn from a similar study of the selected clinical problems which are dealt with by the hospital-based specialist services.

Decision Making↗