Biomedical subjects

M J Bartholomew

Publications and source records attributed to M J Bartholomew.

At least 19 recordsLinked to original sources

PubMed2000

Foundation for nonlinear models with thresholds for longitudinal data.

Threshold models first appeared in the literature nearly half a century ago. Threshold segments have been added to many commonly used forms of models from linear models and generalized linear models through mixed models for the analysis of cross-sectional data. Nonlinear models with thresholds for cross-sectional data are less prevalent in the literature. Nonlinear models with thresholds for longitudinal data are new. The historical developments leading to this point are reviewed as a means of introducing terms necessary for discussing features of these newer models. Nonlinear models for longitudinal data with thresholds are presented and discussed.

Algorithms↗

PubMed1996

Smoking and idiopathic congestive cardiomyopathy.

Two case control studies were performed to evaluate whether smoking may affect myocardial function. Cardiomyopathy subjects had a greater pack year smoking history than 52 control subjects with no CAD (p < 0.02) and were more likely to have diabetes (p < 0.10), but they did not differ from controls with respect to age, alcohol intake, or the presence of hypertension. The risk of cardiomyopathy doubled with an increase of 39 pack years. Smoking history was not related to ejection for fraction for subjects with severe coronary artery disease. These results suggest that smoking may be an important risk factor for idiopathic congestive cardiomyopathy.

Adult↗

PubMed1996

Modeling residue uptake by eggs. 1. Similar drug residue patterns in developing yolks following injection with ampicillin or oxytetracycline.

This study was conducted to model the pattern of antibiotic drug uptake within yolks of developing follicles. In two separate experiments, 16 hens were divided into equal groups (n = 8) and injected only once with either 400 mg/kg ampicillin or 200 mg/kg oxytetracycline (OTC: total hens = 32) approximately 1 h after oviposition. Twenty-four hours following injections, hens were euthanatized and the ovaries were collected. Yolks were dissected free from the individual follicles with a blunt probe. Individual large yellow yolks (> or = 0.2 g) and a pool of 5 small yellow yolks (< 0.2 g) were collected for determination of ampicillin or OTC content. Samples were prepared and assayed using an agar diffusion microbiological method. Selected parameters were not different (P > 0.05) between Experiments 1 and 2 and the data were combined. Results indicate that short-term exposure in hens produced incorporation of drug residues in developing yolks in a specific pattern that does not appear to be drug dependent (P > 0.05). These incurred residues are contained in developing yolks that are days to weeks from being ovulated. Drug residues were greater (total microgram content) in some of the less mature yolks vs the largest preovulatory yolk. This may lead to a sequential release of eggs with increasing residue content, even after drug withdrawal. These data were used to construct a model to predict the pattern of incurred residues in formed eggs following a hen's exposure to drugs or other contaminants.

Ampicillin↗

PubMed1991

Menstrual differences due to vegetarian and nonvegetarian diets.

We studied 41 nonvegetarian and 34 vegetarian premenopausal women whom we closely screened. The two groups were indistinguishable with respect to height, weight, body mass index, and menarche. The incidence of menstrual irregularity was 4.9% among nonvegetarians and 26.5% among vegetarians (P = 0.009). The vegetarian group consumed significantly greater amounts of polyunsaturated fatty acids, carbohydrates, vitamin B-6, and dietary fiber whereas the nonvegetarians reported greater intakes of saturated fatty acids, protein, cholesterol, caffeine and alcohol. Logistic-regression analyses showed that the probability of menstrual regularity among all study subjects (n = 75) was positively associated with increasing protein/kJ and increasing cholesterol/kJ intakes. The probability of being menstrually regular was negatively associated with increasing dietary fiber/kJ and increasing magnesium/kJ intakes. These results are consistent with the notion that menstrual regularity can be influenced by specific dietary nutrients that may have direct effects or exert their effects by modulating circulating sex steroid status.

Adolescent↗

PubMed1991

Effect of pregnancy during TMI crisis on mothers' mental health and their child's development.

Five years after the Three Mile Island nuclear accident, the mental health of women who had been pregnant and living within 10 miles of Three Mile Island at the time of the accident was similar to that of women from the same area who became pregnant after the accident. Ratings of the development of the two groups of children when they were 5 years old were also similar. However, women who were pregnant during the crisis and had been "extremely disturbed" about their pregnancies rated their children's health as poorer than did the women who were pregnant later.

Accidents↗

PubMed1991

Accuracy of papilledema and pseudopapilledema detection: a multispecialty study.

BACKGROUND: Present trends in medical care suggest that primary care physicians will exert increasing control over patient access to medical specialty consultation and diagnostic testing. Therefore, it is important to determine whether primary care physicians can reliably identify papilledema. METHODS: A prospective study involving 429 physicians was undertaken to assess the accuracy of papilledema and pseudopapilledema detection by five groups of physicians, family practice physicians, neurologists, neuro-ophthalmologists, neurosurgeons, and ophthalmologists. RESULTS: Neuro-ophthalmologists and ophthalmologists did better than family physicians, neurologists, and neurosurgeons in identifying both papilledema and pseudopapilledema (P less than .05). Neuro-ophthalmologists more accurately identified pseudopapilledema than all other groups in the study (P less than .05). Family physicians did as well as, or better than, neurologists and neurosurgeons in identifying all classifications of acute and chronic papilledema defined in the study. Family physicians did not perform as well as the other four groups in differentiating pseudopapilledema from papilledema (P less than .05). CONCLUSIONS: Although the sensitivity of detecting papilledema was high (84.5%) for family physicians, the specificity was low (59.3%). Preliminary data indicate that family physicians with prior exposure to clinical ophthalmology in medical school did better than those who had not had training. It is possible that additional exposure to clinical ophthalmology during residency training might yield improved performance.

Clinical Competence↗

PubMed1990

Colonic polyamine content and ornithine decarboxylase activity as markers for adenomas.

Polyamine content (putrescine, spermidine, and spermine) or ornithine decarboxylase (ODC) activity was measured in normal-appearing colonic mucosa from patients undergoing colonoscopy. Comparisons were made between those with and those without adenomatous polyps. Colonic mucosal polyamine content was measured in 44 persons. Mean putrescine content was 1.25 +/- 0.26 (SE) nmol/mg protein in 22 patients with adenomatous polyps compared with 0.53 +/- 0.12 nmol/mg protein in patients without polyps (P less than 0.02). Tissue content of spermidine and spermine did not differ between these two groups. Ornithine decarboxylase activity was measured in tissue from 45 patients. Mean ODC activity was 2.84 +/- 0.73 pmol/hr/mg protein in 23 persons with adenomatous polyps compared with 1.15 +/- 0.18 pmol/hr/mg protein in persons without polyps (P less than 0.05). Mucosal putrescine and ODC activity are elevated in patients with adenomatous polyps compared with patients without polyps. These biochemical markers may prove helpful in improving surveillance methods for colorectal cancer and premalignant adenomatous polyps.

Aged↗

PubMed1990

Treatment with 13-cis-retinoic acid in transfusion-dependent patients with myelodysplastic syndrome and decreased toxicity with addition of alpha-tocopherol.

PURPOSE: The purpose of this study was to determine the response and tolerance to long-term treatment using 13-cis-retinoic acid (13-CRA) in transfusion-dependent patients with the myelodysplastic syndrome (MDS) and to determine the effects of therapy on the natural history of the disease. PATIENTS AND METHODS: Sixty-six consecutive patients with transfusion-dependent MDS seen in a medical school hospital and outpatient clinic from 1981 to 1988 were studied. The first 21 patients were treated with 13-CRA alone and the next 45 patients with 13-CRA plus alpha-tocopherol (AT). We compared responses to and toxicities of therapy, rates of transformation, and survival from onset of therapy in 20 evaluable patients treated with 13-CRA alone and 43 patients treated with 13-CRA plus AT. RESULTS: Four patients responded (20%) at 4 to 8 months to 13-CRA alone, but this response was associated with considerable toxicity and resulted in cessation of therapy. Among the responders, only one continued therapy and is currently in remission, whereas three discontinued therapy because of toxicity and have had a relapse and died. In the 13-CRA plus AT group, we observed one prolonged complete remission and 10 partial remissions (26%), with a decrease in skin and constitutional toxicities by the addition of AT, which enabled the continuation of 13-CRA indefinitely. Although the response rates were similar in both groups, fewer patients (28% versus 60%) experienced progression to acute leukemia in the 13-CRA plus AT group than in the group receiving 13-CRA alone, who terminated treatment (p = 0.018). A twofold increase in median survival of the RA/RARS and RAEB/CMML patient groups was observed with 13-CRA plus AT but was not significant (p greater than 0.5). CONCLUSION: This study shows a 20% to 26% response rate to 13-CRA and suggests that 13-CRA, if given continuously, decreases the rate of progression or transformation to acute leukemia in patients with MDS. The addition of AT ameliorates the toxicity of 13-CRA and allows for long-term treatment with 13-CRA. Since the standard treatment for MDS is currently unsatisfactory, these findings indicate that longer treatment with a non-marrow-suppressive agent such as 13-CRA is important, and further trials to determine the role of 13-CRA plus AT in combination with new recombinant growth factors in the therapy for transfusion-dependent MDS should offer a new approach to a disease common in the elderly population.

Adult↗

PubMed1990

Trauma index revisited: a better triage tool.

In the development of triage and bypass protocols, many different scoring systems and triage criteria are being used. Our purpose was to evaluate the Revised Trauma Index (RTI) as a triage tool for both its severity prediction ability and triage accuracy. A total of 2,340 trauma admissions were evaluated using the RTI and the Injury Severity Score (ISS). The data were submitted to standardized statistical analysis and compared to other published data for under and overtriage. Our results show a linear correlation between the RTI and the ISS with a correlation coefficient of .62. There is 5% death rate at an RTI level of 15, which yields a 5% undertriage rate for death and a 37.3% overtriage rate for predicting an ISS greater than 15. This compares to under and overtriage rates for the Trauma Score, CRAMS, Pre-Hospital Index, and Mechanism of Injury scales varying from 19% to 56% undertriage and 7% to 82% overtriage. We reached the following conclusions. a) The RTI is a simple, fast triage tool for predicting major trauma. b) The RTI is related to the ultimate ISS. c) Use of an RTI greater than or equal to 15 results in an acceptable undertriage rate, with a better rate for overtriage than existing scores. d) Therefore, we recommend the RTI for use in emergency medical direction and bypass protocols.

Computers↗

PubMed1990

FAM chemotherapy +/- aminoglutethimide in the treatment of pancreatic carcinoma.

Human pancreas contains receptors for estrogens and androgens as well as aromatase activity. FAM chemotherapy was administered to 14 patients with pancreatic cancer (seven at Stage IV). The median survival of these patients was 24.4 +/- 4.8 weeks. FAM chemotherapy plus aminoglutethimide/hydrocortisone (AG/HC) (250 mg bid AG + 20 mg bid HC) was administered to 14 patients (seven at stage IV). The median survival of this group was 17.3 +/- 2.9 weeks (P = 0.74 vs FAM alone). We conclude that addition of AG/HC does not add to the survival of patients with carcinoma of the pancreas treated with chemotherapy.

Aminoglutethimide↗

PubMed1989

Pelvic exenteration: a morbidity and mortality analysis of a seven-year experience.

Twenty patients have undergone pelvic exenteration at the University Hospital of the Pennsylvania State University from 1979 to 1985. The majority of operations were performed for cancers of the cervix or vagina that recurred following radiotherapy. Operative mortality was 5.0%. Of those surviving the procedure, 16 patients (84%) were rehospitalized for complications that occurred more than 30 days after exenteration. The majority of these involved the gastrointestinal or urinary tracts. Fifty-eight percent of the complications requiring surgical intervention occurred more than 1 year after surgery while 74% of the complications managed conservatively occurred within 1 year of surgery. The 2-year survival for all patients was 70%; survival decreased to 58% at 5 years. The most important risk factor for reduced survival was the extension of tumor laterally into the surgical margins.

Adult↗

PubMed1989

Chemotherapy plus RA233 in the treatment of oat cell lung cancer.

One hundred and one patients with oat (small) cell lung cancer have been treated with CAVE [Cytoxan, Adriamycin, Vincristine, and etoposide (VP-16)] chemotherapy +/- RA233 (a platelet-inhibiting agent). There was no difference in disease-free interval, pattern of relapse, or survival between groups.

Actuarial Analysis↗

PubMed1989

The onset of sperm production in pubertal boys. Relationship to gonadotropin excretion.

To determine the relationship of gonadotropin excretion to spermarche, 26 boys ranging in age from 10.3 to 17.5 years each provided ten overnight urine samples. Microscopic observation of sperm was found in 33 (13%) of the 260 samples, with 50% of the boys exhibiting sperm in at least one specimen. No further cumulative gain in detecting spermaturia occurred after the seventh urine collection. The median age of spermarche was computed by logistic regression analysis to be 14 years. Three urine collections from each boy were assessed for gonadotropin levels. At age 14 years mean follicule-stimulating hormone and luteinizing hormone excretion were, respectively, 857 and 503 mIU/h, into the reported adult daytime range. Spermarche is a midpubertal event associated with age-appropriate gonadotropin production.

Adolescent↗

PubMed1989

Immunologic monitoring studies in advanced cancer patients treated with recombinant human gamma interferon (IFN-gamma 4A).

Thirty-nine patients with a variety of advanced malignancies were treated with recombinant IFN-gamma 4A (AMGen, specific activity 1 to 5 x 10(7) U/mg protein). IFN-gamma 4A was administered at a dose of 10-2,000 micrograms/m2/d. Following a 2-week rest, a maintenance phase was continued with injections 3 d/wk. Immunologic monitoring studies were performed on patients' peripheral blood cells before administration of IFN-gamma 4A, then on Days 15 and 90. Flow cytometric analysis was used to determine the absolute number of CD 3+, CD 4+, CD 8+, CD 19+, and CD 16+ cells using a panel of monoclonal antibodies. Natural killer (NK) cell function was assayed by monitoring lysis of the K562 cell line in the Cr51 release assay. Changes from baseline were observed on Days 15 and 90 in all parameters studied, although the ratio of helper to suppressor cells seemed to remain within the normal range. Whereas there were no substantial changes in CD 3+ and CD 4+ cells on Day 15, IFN-gamma 4A had an enhancing effect on CD 8+, CD 19+, and CD 16+ cells. This trend continued at Day 90 only for CD 19+ and CD 16+ cells at the higher dose levels. An increase in functional NK cell activity at Day 15 was less noted on Day 90. Comparison of intravenous (IV) to intramuscular-subcutaneous (IM-SC) administration showed differences in the effect on lymphocyte subpopulations at 450 and 1,000 micrograms. The effect of IFN-gamma 4A on the equilibrium among lymphocyte subpopulations and the possibility of its role in combination therapy with other biologic response modifiers are discussed.

Antigens, CD↗

PubMed1988

Unmet needs of persons with cancer in Pennsylvania during the period of terminal care.

A stratified random sample of recent cancer deaths was drawn from the Pennsylvania death registry, and 433 family members or close friends were interviewed concerning unmet needs during the last month of life. It was estimated that 72% of persons who died of cancer in Pennsylvania experienced at least one unmet service need during this period. The most frequently reported was help with activities of daily living, estimated at 42% of cancer deaths, involving over 11,000 persons each year in the state. There were significantly more unmet needs during the terminal period, compared with just after diagnosis, in activities of daily living, obtaining health care, transportation, and problems with medical staff. Our findings indicate a need to increase a broad range of support programs during the terminal period, especially of home-care services.

Activities of Daily Living↗

PubMed1988

Correlation of aromatase activity with histological differentiation of breast cancer--a morphometric analysis.

Differentiation is a term that indicates the degree to which a tumor resembles histologically the tissue or cell of origin. A system to quantitate the proportion of breast cancer cells participating in glandular differentiation or remaining within ducts was employed. The degree of tumor differentiation of 58 primary breast cancers was correlated with estrogen (ER) and progesterone receptors (PR) and tumor aromatase activity. There was a significant association between tumor differentiation (greater than or equal to 2% cancer cells exhibiting glandular differentiation) and the presence of ER or PR in tumors. Conversely, there was no correlation between tumor differentiation and measurable tumor aromatase activity.

Aromatase↗

PubMed1988

A comparison of problems reported by persons with cancer and their same sex siblings.

Problem reporting rates of 180 persons with cancer (PWC) were compared with those of their closest in age same sex cancer-free siblings living outside their households for the same time periods. PWC had significantly higher reporting rates for physical, activities of daily living, nutrition, and emotional problems and a significantly lower rate for family problems. Sibling problem reporting rates, which indicate the likelihood that PWC would have experienced similar problems without a diagnosis of cancer, were highest for physical, emotional, employment, and family problems suggesting that noncancer factors are especially likely to play a role in those types of problems. Regression analyses showed that female and younger PWCs tended to report more problems than their siblings suggesting that they were more affected by cancer and its treatments than were other types of PWC.

Activities of Daily Living↗

PubMed1988

The influence of body weight on lipoprotein lipids in patients with polycystic ovary syndrome.

Lipoprotein lipid and androgen profiles were compared after a 12-hour fast that involved 13 women with polycystic ovary syndrome and 13 who did not have the syndrome. All women were matched for percent ideal body weight. As expected, patients with polycystic ovary syndrome had significantly higher luteinizing hormone--to--follicle-stimulating hormone ratios, higher testosterone levels, higher free testosterone levels, higher dehydroepiandrosterone sulfate levels, and lower testosterone-estradiol-binding globulin binding capacity than the other women. Patients with polycystic ovary syndrome had significantly higher mean serum triglyceride levels, very-low-density lipoprotein cholesterol levels, and lower high-density lipoprotein cholesterol levels. Differences in body weight do not explain the male pattern of lipoprotein lipid concentrations in women with polycystic ovary syndrome. The association of hyperandrogenism with lipoprotein lipid abnormalities should be evaluated in regard to the influence of endogenous sex steroids on differences between the sexes in incidence of cardiovascular disease.

Adult↗