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Biomedical subjects

R F Jones

Publications and source records attributed to R F Jones.

At least 91 records · Page 5Linked to original sources
PubMed1987

Preliminary studies of monoclonal antibody lymphoscintigraphy in malignant melanoma.

Lymphoscintigraphy was performed at 3 and 20 hr following subcutaneous injection of 131I anti-melanoma antibody (Fab) in 11 patients who had surgical resection of lymph nodes (neck, axilla, groin) at 24 hr for suspected metastatic melanoma. Comparable amounts of 125I nonspecific control antibody (Fab) were co-administered. Six patients had nodal metastases and three showed positive images at both time periods. Five patients had no metastases though one was image positive. Four other nondiseased inguinal node groups were image negative. A total of 28 tumored nodes and 110 normal nodes were removed, counted and histologically examined. All metastatic tumors expressed antigen against which the specific Fab was directed. The concentrations of both specific and nonspecific Fab were similar in tumored nodes and both were significantly greater than in normal nodes showed essentially identical intranodal spatial distribution of the specific and control Fab in areas containing tumor. These preliminary results suggest the increased concentration of murine immunoglobulin (Fab) retained in diseased nodes was a nonspecific phenomenon.

Adult↗
PubMed1986

A common mouse mammary tumor virus integration site in chemically induced precancerous mammary hyperplasias.

Mammary carcinomas can be induced by chemical and hormonal as well as viral carcinogens. Irrespective of the class of inducer, these tumors develop in discrete stages, of which alveolar hyperplasia is one of the earliest identifiable. Since carcinogenesis by the mammary tumor virus is now thought to involve proviral activation of adjacent cell genes at specific loci, we sought to determine if a similar mechanism also played a role in chemical and hormonal carcinogenesis and if its role was stage specific. Three high-tumor-incidence BALB/c hyperplastic alveolar nodule outgrowths of two different etiologies were found to have exogenous mouse mammary tumor virus proviruses integrated at the same site in the genome. This common site of integration is not within the bounds of the int-1 and int-2 loci into which proviruses detected at these loci are clustered in MMTV-induced mammary tumors. All three HANs are commonly impaired in end-point differentiation. We propose that mouse mammary tumor virus integration at this site is responsible for a specific abnormality in differentiation associated with the preneoplastic phenotype.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1986

The effect of commercial coaching courses on performance on the MCAT.

Two studies on the relationship between taking a commercial coaching course and performance on the Medical College Admission Test (MCAT) are reported. In both studies, one based on repeating examinees and another based on first-time examinees, differences in scores favoring coached examinees were found on the Science Knowledge and Science Problems subtests. The results on the Skills Analysis: Quantitative subtest were mixed, while neither study found differences between the two groups in scores on the Skills Analysis: Reading subtest. The analyses further revealed that the differences in scores on the Science Knowledge and Science Problems subtests were less pronounced for examinees with low scores on the Skills Analysis: Reading and Skills Analysis: Quantitative subtests, examinees with very low or very high undergraduate grade-point averages, and examinees from very selective undergraduate colleges. The substantive importance of the differences was also explored. The coaching effect was estimated to increase an average student's probability of acceptance by 5 percentage points. The results suggest that coaching for the MCAT has a limited effect that supports rather than undermines the validity of the test.

Adult↗
PubMed1986

Predicting academic performance at a predominantly black medical school.

A study was conducted by the authors that examined the validity of the Medical College Admission Test (MCAT), undergraduate grade-point average (GPA), and "competitiveness" of undergraduate college in predicting the performance of students at a predominantly black college of medicine. The performance measures used in the analysis consisted of course grades in all four years of medical school and scores on both Part I and Part II of the National Board of Medical Examiners (NBME) examinations. The predictive validities of the MCAT scores and undergraduate GPAs were found to be similar to those revealed in earlier studies conducted at predominantly white schools. Two exceptions to these similarities were found. First, the MCAT scores at the black school had a somewhat lower validity in predicting NBME examination scores than was the case at the other schools. Second, of the six MCAT subtest scores, Skills Analysis: Reading had the highest correlation with first-year grades, in contrast to results at the other schools. No differences between men and women were found in the validity of MCAT scores and the GPA. The competitiveness of the undergraduate college attended was found to contribute significantly to the prediction of all measures of medical school performance.

Black or African American↗
PubMed1986

Preclinical curriculum characteristics and institutional performance on NBME. Part I.

A study was conducted that analyzed the relationship between various characteristics of the preclinical curriculum and institutional performance on the Part I examination of the National Board of Medical Examiners (NBME) at a sample of 85 U.S. medical schools. Total scheduled hours per week was the single curriculum characteristic having a positive and significant relationship with institutional NBME examination performance. However, when the data were controlled by medical school selectivity in admissions and institutional policy on the taking of the examination, total scheduled hours per week failed to make a significant contribution to the prediction of performance. The results were viewed as failing to provide support and justification for intense preclinical curriculum loads on the basis that this would enhance NBME examination performance. The authors conclude that simple comparisons of schools on the basis of mean NBME examination performance are meaningless unless the entering abilities of students and school policies on the examination are taken into account. The authors also suggest that those schools that prescribe heavy and intense preclinical curriculum loads should reexamine those policies in light of recommendations of the Project Panel on the General Professional Education of the Physician and College Preparation for Medicine.

Certification↗
PubMed1985

Comparison of Bacteroides zoogleoformans strains isolated from soft tissue infections in cats with strains from periodontal disease in humans.

A total of 11 strains of Bacteroides zoogleoformans were isolated from 11 of 106 different cat subcutaneous "fight wound" abscesses and were among a total of 143 Bacteroides species isolated from these samples. They constituted 3.4% (11 of 325) of all anaerobic isolates. The cat strains and strains of B. zoogleoformans isolated from humans with periodontal disease were similar phenotypically as determined by biochemical reactions, polyacrylamide gel electrophoresis patterns of soluble proteins, and guanine plus cytosine ratios of DNA. Eight cat strains and five human strains tested had 45 to 54% DNA homology with the type strain of B. zoogleoformans. The eight cat strains and five human strains (excluding the type strain) were related by DNA homology at 70 to 77%. There was 85 to 90% intragroup DNA homology among the cat strains and 86 to 89% intragroup homology among the five human strains. The implications for epidemiology and human and animal ecology are discussed.

Animals↗
PubMed1985

Clinical practice of medical school faculties: an AAMC survey of problems and issues.

This study reports the results of a survey by the Association of American Medical Colleges (AAMC) to identify the salient problems and issues regarding medical school faculty clinical practice in the views of faculty members and administrators in academic medical centers. The population surveyed consisted of university vice-presidents for health affairs, teaching hospital directors, and medical school deans, department chairmen, and faculty representatives. A content analysis of the narrative responses revealed that the apportionment of faculty time to create the appropriate institutional balance among teaching, research, and service missions was the most frequently mentioned concern. Other dominant themes included threats to the patient base needed for teaching and research and/or to future income posed by the new competitive and reimbursement environment and changes required in modes of faculty practice to respond to the new environment. The latter included the need for organizing practice activities into a "true group practice," a change that would accommodate growing demands of purchasers for integrated systems of care. Hospital directors were particularly concerned with issues of faculty-hospital relationships. Results of the survey provide an agenda for a recently formed AAMC ad hoc Committee on Faculty Practice, which will propose initiatives by the AAMC to assist its member institutions in responding to the issues raised.

Academic Medical Centers↗
PubMed1984

Conversion reaction presenting as acute spinal cord injury.

A conversion reaction, presenting as an acute spinal-cord injury, was diagnosed in 9.8% of new patients admitted to a spinal injury unit during the period from November 1982 to November 1983. There were eight men and one woman (mean age, 23 +/- 8 years). A history of previous episodes of conversion reaction was common in this group. Some patients had evidence of previous vertebral damage. Diagnosis of this condition is difficult, even for those who are familiar with patterns of spinal-cord injuries. All patients were walking independently and had no sensory deficits at the time of discharge from hospital.

Acute Disease↗
PubMed1984

Use of isoelectric focusing of bacterial proteins for characterisation of strains of motile anaerobic "corroding" bacteria isolated from soft tissue infections in cats and dogs.

Isoelectric focusing of bacterial proteins in 1 mm thick agarose gels and ultrastructural analysis of cell walls were used to facilitate characterisation of motile "corroding" bacteria from subcutaneous abscesses and pyothorax infections from cats and dogs. Some of the motile "corroding" rods had ultrastructural cell wall features identical with Wolinella recta described from human periodontal pockets. Other strains had the more conventional cell wall ultrastructure of Gram negative bacteria. Isoelectric focusing of bacterial proteins divided the motile "corroding" strains into two groups. These groups correlated with the ultrastructural appearance of the cell walls. It is considered that isoelectric focusing techniques using 1 mm thick agarose gels may provide a more rapid method for ultimate differentiation of these organisms than other methods described so far.

Animals↗
PubMed1984

Validity of the MCAT in predicting performance in the first two years of medical school.

In this paper, the authors present the first systematic summary of predictive validity research on the new Medical College Admission Test (MCAT) since its introduction in 1977. Data are drawn primarily from the MCAT Interpretive Studies Program, a cooperative effort between the Association of American Medical Colleges and 30 of its member schools to conduct research that will both facilitate local use of the test scores and contribute to a national perspective on their value in medical school admissions. The results show that MCAT scores by themselves have significant predictive validity with respect to first- and second-year medical school course grades and National Board of Medical Examiners Part I examination scores and that they complement the predictive validity of undergraduate college grades. The MCAT Science Knowledge areas of assessment, particularly Biology and Chemistry, and the Science Problems subtest tend to have higher correlations than the Skills Analysis subtests with initial performance in medical school; however, the Skills Analysis: Reading subtest may retain its predictive value best over time. Correlation values are discussed in terms of methodological factors which constrain their size. They are also compared with those found for other professional and graduate school admission tests. Further directions for MCAT validity research are described.

Achievement↗
PubMed1984

Odontoid fractures, systemic disease and conservative care.

Patients admitted to the Prince Henry Hospital Spinal Unit between January 1982 and January 1983 with a diagnosis of fracture of the odontoid process of the axis were reviewed. There were nine patients representing 20% of all new cervical fractures. The mean age was 64.5 +/- 19.3 years. Alcoholism, brain damage following head injury, osteo-arthritis, cervical spondylosis, rheumatoid arthritis and osteoporosis may be complicating factors in the management of odontoid fractures. A fracture of the odontoid in an elderly patient with a history of minimal trauma suggests osteoporosis. Early mobilization in a custom-moulded orthosis with frequent radiological monitoring prevents the complications of prolonged bed rest.

Aged↗
PubMed1984

Comparison of strains of gram-negative, anaerobic, agar-corroding rods isolated from soft tissue infections in cats and dogs with type strains of Bacteroides gracilis, Wolinella recta, Wolinella succinogenes, and Campylobacter concisus.

A total of 64 strains of gram-negative, asaccharolytic, anaerobic, agar-corroding, rod-shaped bacteria from soft-tissue infections of cats and dogs were compared with other agar-corroding, anaerobic organisms isolated from human periodontal pockets (Wolinella recta ATCC 33238T), bovine rumens (Wolinella succinogenes ATCC 29543T), and gingival crevices of humans (Bacteroides gracilis ATCC 33236T and Bacteroides ureolyticus NCTC 10941T). Campylobacter concisus ATCC 33237T (from human gingival crevices) which did not corrode agar but which biochemically resembled organisms in this group was also included in this study. Although the type strains of W. recta, W. succinogenes, and B. gracilis resembled the animal strains phenotypically and in DNA base ratios, none had bacterial protein patterns (as indicated by isoelectric focusing) identical with the animal strains studied. The animal strains could be divided into motile and nonmotile groups. The motile animal strains were similar biochemically but could be divided into three groups by isoelectric focusing of bacterial proteins. Some had cell wall ultrastructural features identical with W. recta; others had the smooth walls of conventional gram-negative organisms. One group of nonmotile animal strains closely resembled B. gracilis phenotypically, and they had the cell wall ultrastructure of conventional gram-negative bacteria as described previously (4). The other nonmotile group had cell wall ultrastructure like that of W. recta.

Agar↗
PubMed1983

Equine herpesvirus abortion in Australia 1977 to 1982.

Until 1977 no case of abortion caused by equine herpesvirus 1 (EHV1) had been recorded in Australia although the virus, called equine rhinopneumonitis virus, had been known to have been present at least since 1962. Outbreaks of EHV1 abortion occurred in New South Wales in 1977 and in 1981. Sporadic cases of EHV1 abortion had been confirmed in some parts of Australia each year since 1975. It was concluded that an abortigenic subtype of EHV1 had been introduced to Australia in 1977 and that the previously endemic respiratory subtype occasionally caused abortion. Virus isolation in a variety of cell cultures and histopathological examination of tissue were shown to be satisfactory methods of diagnosis of EHV1 abortion. Lung proved to be the specimen of choice. Slight serological differences between "abortigenic" and "respiratory" subtypes of EHV1 were found in cross neutralisation tests. A serological survey of 219 Sydney horses of various ages revealed that most yearlings had already acquired neutralising antibody to both subtypes.

Abortion, Veterinary↗