Biomedical subjects
Publications and source records attributed to D J Solomon.
Although esophageal intramural pseudodiverticulosis is well described, similar pathology has not been demonstrated elsewhere in the gastrointestinal tract. Three cases are reported with identical changes in the duodenum, one of which had simultaneous esophageal involvement. All three patients were alcohol abusers.
This pilot study evaluates the consistency of experts' ratings of students' performances on the National Board of Medical Examiners' Computer Based Examination (CBX) cases and the relationship of those ratings to the CBX's scoring algorithm. The authors were investigating whether an automated scoring algorithm can adequately assess an examinee's management of a computer-simulated patient. In 1989-90, at the Michigan State University College of Human Medicine, eight students, completing a surgery clerkship, each managed eight CBX cases and took a computer-administered, multiple-choice examination. Six clerkship coordinators rated the students' performances in terms of overall management, efficiency, and dangerous actions. The ratings correlated highly with scores produced by the CBX's scoring system.
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Oesophageal intramural pseudodiverticulosis is characterized by a segmental or diffuse distribution of numerous small outpouchings varying in size from 1 to 5 mm. Review of previously described cases revealed a significant incidence of associated debilitating systemic disorders such as diabetes mellitus, malignancy, alcoholism and tuberculosis. No record could be found in the literature of a similar process occurring in other parts of the gastro-intestinal tract. A case is reported of a severe alcoholic who, on a barium swallow, in addition to the changes of oesophageal intramural pseudodiverticulosis, presented with a large duodenal ulcer and similar outpouchings in the first and second parts of the duodenum.
Intussusception of the appendix into the caecum is an uncommon condition and the diagnosis is rarely made preoperatively. Specific anatomic requirements as well as pathological conditions that cause irritation or increased peristalsis should be present for this event to occur. A case is discussed in which the diagnosis was made preoperatively by barium enema and in which the lead point was a large inflammatory polyp due to Crohn's disease. It appeared in this case that inflation at the time of the barium enema resulted in reduction of the intussusception.
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In the 1988 study reported here, Medical College Admissions test (MCAT) scores and grade point averages for undergraduate science courses (S-GPAs) were examined for predictive validity and differential prediction of National Board of Medical Examiners Part I scores. Data from 579 medical students from the classes of 1979-80 through 1983-84 attending a midwestern medical college were analyzed via moderated multiple regression. The findings indicated that using the S-GPA and a composite MCAT score based on the Biology Knowledge, Chemistry Knowledge, Physics Knowledge, Science Problems, and Reading subtests was valid and equally predictive for the minority and majority groups studied. These results are discussed in terms of past findings on cognitive tests in general, and the MCAT and the S-GPA specifically.
In 48 patients referred for radiological evaluation as part of an investigation for benign prostatism both intravenous urography and ultrasonography were used. Ultrasonography combined with a plain abdominal radiograph was shown to be a better investigation than intravenous urography. Ultrasound was equally sensitive in detecting changes in the upper tracts and post-micturition residual volume and was more accurate in estimating prostate size. Intravenous urography was slightly more sensitive in detecting bladder wall changes, but this was not of clinical significance.
A case of duodenal diaphragm diagnosed by ultrasound is presented. The case was associated with situs inversus.
Exposure of hamsters to short days increases sensitivity to the negative feedback effects of testosterone (T) but decreases responsiveness to the behavioral effects of the hormone. Since T is metabolized in the brain to 5 alpha-dihydrotestosterone (DHT) and estradiol, which differentially affect gonadotropin secretion and sex behavior, it is reasonable to postulate that daylength can modulate neural responses by quantitative or qualitative alterations in T metabolism and subsequent receptor binding of active hormone. Experiments reported here focused on aromatization and the nuclear accumulation of estrogen receptors. Adult male hamsters were maintained for 6-12 wk in long (14:10 LD) or short (8:16 LD) daily photoperiods. Both intact and castrated animals were used to assess direct effects of short days versus changes due to short-day-induced testicular regression. Discretely dissected regions of the brain (preoptic area, POA; hypothalamus, HTH; and corticomedial amygdala, CMA) or limbic blocks (LIM) comprised of all three regions were assayed for estrogen-synthesizing activity (aromatase) and estrogen-binding activity (receptors). Aromatase was estimated in vitro by conversion of [7-(3)H] androstenedione to [3H] estrogen and in vivo by measuring increases in nuclear estrogen receptor levels after injection of aromatizable androgen. Receptor-binding activity was assayed in crude cytosolic and nuclear extracts by incubating samples with [3H] estradiol +/- 100-fold excess inert estradiol, and separating free and bound steroids by Sephadex LH-20 gel filtration. When aromatase was assayed in homogenates prepared from discrete brain regions of individual hamsters, significantly lower activity was found in the HTH of short-day animals than in long-day controls. This effect was seen in both intact and castrated animals, which indicates that it was not mediated by the testis. Decreased enzyme activity in the POA and CMA of short-day hamsters was not significant, nor was there an effect of castration independent of short days. Low levels of nuclear estrogen receptors were present in LIM of intact males, but these were reduced after castration or concomitant with testicular regression after short-day exposure. This suggests that the hamster testis normally secretes estrogen or aromatizable androgen. A single injection of estradiol or aromatizable androgen (T or androstenedione) increased nuclear receptors in LIM of castrated animals. Cytosolic receptors were not different in short-day vs. long-day hamsters, nor were there differences in nuclear receptor levels after a single estradiol injection.(ABSTRACT TRUNCATED AT 400 WORDS)
Traumatic third nerve palsy is an unusual condition. It is a serious prognostic feature, not for life but for permanent, serious neurological deficit. It can only be diagnosed with confidence if it is known to have been present from the moment of impact and if adequate investigation excludes a compressing haematoma.
In order to gain direct evidence for lipid-dependent protein conformation in membrane, effects of modification of lipid composition on mobility of spin-labeled cysteine residues were investigated in the plasma membrane of the yeast Saccharomyces cerevisiae. Conversion of the bulk of phospholipids to diglycerides by treatment of the membrane with phospholipase C substantially enhanced spectral anisotropy. However, alterations of the viscosity of the lipid-bilayer by enriching the membrane with palmitelaidic or oleic acid had no effect on mobility of spin-labeled cysteine residues. These observations indicate that while the spin-labeled residues are not in direct contact with the lipid core of the membrane, there are lipid-protein interactions to the extent that removal of the polar portion of the bulk of phospholipids induces conformational changes in proteins, which in turn restrict mobility of these residues. It is concluded that conformation of membrane proteins on lipid structure and that phospholipids have a role in preserving the native conformation of proteins.
Illustrated explanations of various diagnostic radiology procedures have been designed to inform children and their parents precisely what will occur during the examinations. These explanations have been well received and may be requested from the author's.
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The Michigan Medicaid Program payment records generated in the period 1985-89 by 783 persons were analyzed for services related to human immunodeficiency virus (HIV) infection. Other data from death records and the Michigan AIDS Surveillance Registry were available for a subset of those persons. The average monthly payment in 1989 dollars for HIV-related services was $1,302.57. Services determined to be unrelated to HIV infection accounted for 12.5 percent of the total amount for health care received and another 2.5 percent was questionable. The average monthly expenditure for men was roughly twice that for women. The discrepancy did not exist among persons identified in the AIDS Surveillance Registry. Sex differences ceased to exist when Medicaid eligibility (disability versus Aid to Families with Dependent Children) was controlled for by analysis of variance. There were no significant differences between payments to those infected through male-to-male sexual contact and those infected through intravenous drug use. Payments for HIV treatments rose with age to about 40 years, and declined slightly among older adults. The sharpest rise was for those ages 19-25 years and 26-35 years. Large sex differences existed among those who received zidovudine (AZT), 61.4 percent of the men and 19.1 percent of the women. Controlling for Medicaid eligibility moderated those differences, but they remained statistically significant. Differences in zidovudine usage were not found between men and women in the subset identified in the AIDS Surveillance Registry nor among persons infected through male-to-male sexual contact and intravenous drug use.
A rapid proliferation of registries has occurred during the last 20 years. Given the long-term commitment of resources associated with registries and limited public health funding, proposals for new registries should be carefully considered before being funded. A registry is defined as a data base of identifiable persons containing a clearly defined set of health and demographic data collected for a specific public health purpose. Criteria for evaluating whether a registry is needed, feasible, or the most effective and efficient means of collecting a specific set of health data are presented. They include an evaluation of the stated purpose; a review of the function, duration, and scope of the registry; consideration of existing alternative data sources; an assessment of the practical feasibility of the registry; the likelihood of sufficient start-up and long-term funding; and an evaluation of the cost effectiveness of the registry. Creating a public health registry is a complex process. A range of technical and organizational skills is required for a registry to be successfully implemented. Eight requirements are identified as crucial for the successful development of a new registry. They include an implementation plan, adequate documentation, quality control procedures, case definition and case-finding (ascertainment) procedures, determination of data elements, data collection and processing procedures, data access policy, and a framework for dissemination of registry data and findings.
To obtain better understanding of the nature and cost of health care related to human immunodeficiency virus (HIV) infection, medical payment records were analyzed for 204 men, women, and children older than 60 months who had indications of HIV infection. The records were those of Michigan Medicaid, the General Assistance Medical Program, and the Resident County Hospitalization Program, with service dates on or after January 1, 1984, and which were processed by November 30, 1987. Patient payment records were coded according to whether the patient's condition was considered to be pre-HIV, HIV unrelated, possibly HIV related, or HIV related. Average monthly payments were found to be $150 for pre-HIV patient payment records, $114 for those HIV unrelated, $57 for those possibly related, and $1,213 for those related to HIV infection. HIV-related monthly payments rose from about $1,500 per month in the period 3 months prior to the patient's death to more than $8,000 in the last month of life. Men were found to have twice as many claims as women, and men's claims cost about three times as much. A higher percentage of women than men (91 percent versus 37 percent) received pre-HIV paid services, indicating a higher percentage of women were at least initially receiving Medicaid for reasons other than an HIV-related disability. Diagnostic categories that accounted for the bulk of the HIV-related health care utilization included infectious and parasitic diseases, acquired immunodeficiency syndrome, diseases of the respiratory system, and non-HIV-specific immunity disorders. Inpatient hospitalization accounted for more than 75 percent of the payments, followed by physician costs (11 percent), pharmacy costs (5 percent), and outpatient costs (3 percent). A total of 45, or about 22 percent of the recipients, received zidovudine (AZT) prescriptions at an average monthly cost of $404.