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Biomedical subjects

J Howard

Publications and source records attributed to J Howard.

At least 19 recordsLinked to original sources
PubMed1992

A collaborative study of differences in the survival rates of black patients and white patients with cancer.

In 1983, the National Cancer Institute began a social-epidemiologic study of possible behavioral and biologic determinants of black/white racial disparities in cancer survival. The design, methodology, underlying hypotheses, and patient accrual of this study are discussed. Survival differences in four organ sites are investigated: cancers of the uterine corpus, breast, bladder, and colon. The first three sites were chosen because of significant observed black/white differentials in survival. Although racial disparities in survival from colon cancer are less prominent, this site was included because it is a leading cause of deaths attributable to cancer, because regional variations have been observed in black/white survival disparities, and because colon data permit cross-gender comparisons. Data collection centers for the study included the Georgia Center for Cancer Statistics, the Louisiana Tumor Registry, and the California Tumor Registry. Probability samples of patients newly diagnosed with these cancers were drawn from the areas served by these registries. Diagnostic years of eligibility were 1985 to 1986 for breast and colon cancer, and 1985 to 1987 for bladder and uterine corpus cancer. Data were collected by personal interview, medical records abstract, physician records, and pathology review. Analyses focus on seven main explanatory hypotheses.

Adult↗
PubMed1992

Youth suicide in New South Wales: urban-rural trends.

OBJECTIVE: The study tested the hypotheses that (i) the rate of suicide by firearms among youth (aged 10-19 years) is increasing at a greater rate than rates of suicide by other methods; (ii) the rate of youth suicide in rural New South Wales is significantly higher than those in urban areas; and (iii) the increase in youth suicide by means of firearms is occurring at a greater rate in rural males aged 15-19 years than in other groups. DESIGN: Data were obtained from the NSW Office of the Australian Bureau of Statistics concerning 735 youth suicides in NSW between 1964 and 1988. These were reviewed for information concerning residential area and method of death. Five five-year periods were used, and rates were calculated with population figures obtained in the census years for the same age and sex group. RESULTS: From 1964 to 1988, suicide by firearms has risen most substantially, from 3.4 to 5.6 per 100,000 per year in 15-19-year-old males. There has also been a substantial increase in 15-19-year-old male suicides by hanging (0.7 to 3.4 per 100,000 per year). Poisoning suicides have declined among females and males in the past 15 years. Suicide rates in Sydney, Newcastle and Wollongong have remained stable. In rural cities, they have increased from 1.5 to 4.7 per 100,000 per year (F = 4.9, P less than 0.02) while in rural municipalities and shires they have increased from 1.3 to 6.4 (F = 14.6, P less than 0.0001). The suicide rate of 15-19-year-old males has shown a modest increase in Sydney and no change in Newcastle or Wollongong, but the rate for 15-19-year-old males in rural cities has more than doubled, from 5.1 to 12.5 (F = 7.7, P less than 0.003), while in rural municipalities and shires, the rate has increased more than fivefold, from 3.9 to 20.7 (F = 9.3, P less than 0.001). There has been no significant change in the suicide rates of 15-19-year-old females, or in 10-14-year-olds. The rate of suicide by firearms among 15-19-year-old males has not risen significantly in rural cities, but in rural municipalities and shires the rates have risen fivefold from 2.8 to 14.8 (F = 5.6, P less than 0.01). CONCLUSIONS: Each hypothesis was confirmed. An increase of this magnitude is not an artefact of coroners' verdicts. The findings are believed to be due to ready access to firearms, the use of alcohol and drugs (particularly in firearms suicides) and increasing socioeconomic, health, and identity problems for rural youth, especially males.

Adolescent↗
PubMed1992

Morphologic aspects of pericardial heart disease: Part I.

Pericardial heart disease is a common entity at necropsy. Frequently, focal areas of fibrin deposits or parietal-visceral pericardial adhesion are observed at necropsy without previous clinical evidence of pericardial dysfunction. Some of these instances are related to clinically silent acute or healed myocardial infarction, but the vast majority of cases are incidental (idiopathic) findings. The purpose of this review is to summarize various morphologic responses of the pericardium and to provide an etiologic framework for these responses. Part I will review general morphologic responses of pericardial layers.

Heart Diseases↗
PubMed1992

Morphologic aspects of pericardial heart disease: Part II.

Pericardial heart disease is a common entity at necropsy. Frequently, focal areas of fibrin deposits or parietal-visceral pericardial adhesion are observed at necropsy without previous clinical evidence of pericardial dysfunction. Some of these instances are related to clinically silent acute or healed myocardial infarction but the vast majority of cases are incidental (idiopathic) findings. The purpose of this review is to summarize various morphologic responses of the pericardium and to provide an etiologic framework for these responses. Part II will review specific morphologic responses of pericardial layers to selected diseases.

Cardiac Surgical Procedures↗
PubMed1992

Fibronectin staining detects micro-organisms in aged and Alzheimer's disease brain.

Filamentous, fibronectin-immunopositive structures, previously described in Alzheimer's disease and control brains were negative for neuronal, glial, and macrophage markers. The present study sought to determine the nature of these entities and to further characterize their morphology, immunoreactivity and distribution between neuropathologies. Ultrastructural analysis shows these formations to be filamentous micro-organisms, which may belong to the actinomycetes. Immunohistochemistry for the cell-stress protein ubiquitin is consistently positive in these organisms. They are also present in Down's syndrome, dementia pugilistica, amyotrophic lateral sclerosis with dementia, and Parkinson's disease. The pattern of tissue distribution implies a pre-mortem invasion of the brain, and, as the micro-organism is present at a four to five-fold higher frequency in Alzheimer's disease, it may act pathogenically in this dementing illness.

Actinomyces↗
PubMed1992

Evaluation of clinical nurse specialist practice.

Evaluation of the impact of clinical nurse specialist (CNS) practice in today's health care environment is currently one of the most important issues facing these advanced practitioners and nursing administrators. The unique contributions of CNS practice can be demonstrated through use of sophisticated evaluation methods. This paper begins with a discussion of types of evaluation (structure, process, and outcome) that have been utilized in the past and then describes the structure, developmental process, and function of an evaluation instrument recently implemented by a group of CNSs. The evaluation instrument is a step towards the ultimate goal of process-outcome evaluation, the most sophisticated method of evaluating the impact of the CNS. The benefits of utilization of this tool are presented from the perspective of CNSs and nurse administrators.

Employee Performance Appraisal↗
PubMed1991

Catheter balloon valvuloplasty of stenotic aortic valves. Part I: Anatomic basis and mechanisms of balloon dilation.

Catheter balloon valvuloplasty of stenotic aortic valves has met with generally poor short- and long-term clinical results. Part of this problem resides with the lack of recognition of various etiologies of aortic stenosis. Part I of this review discusses the various etiologies of aortic stenosis and provides an anatomic basis for successful valve dilation. Results of an in vitro study indicate stenotic aortic valves are dilated by various mechanisms (cracking, stretching) based in part upon the etiology of the aortic valve stenosis.

Adult↗
PubMed1991

An immunoaffinity immobilized enzyme assay for neomycin phosphotransferase II in crude cell extracts.

An immunoaffinity immobilized enzyme assay for neomycin phosphotransferase II (NPT II) has been developed. This method combines affinity purification with an enzyme-catalyzed reaction. The assay is mechanically simple and can be semiautomatable since all steps are performed in a microtiter plate. An immunoaffinity step separates NPT II from endogenous kinases, which may produce false positive results, and from endogenous phosphatases and inhibitors, which decrease the apparent NPT activity. This method thus exploits two modes of specificity: antigen-antibody specificity and enzyme catalysis specificity. This gives a high degree of specificity and allows quantitation of 0.1 ppm NPT in crude plant protein extracts. The catalytic ability of the NPT is not significantly hampered by its attachment to the gel, in the Km values for ATP and neomycin and the catalytic number for immobilized NPT are comparable to those for the NPT in solution.

Adenosine Triphosphate↗
PubMed1991

Estimation of myocardial infarct size with ultrasonic tissue characterization.

BACKGROUND: Ultrasonic tissue characterization (UTC) can distinguish normal from infarcted myocardium. Infarcted myocardium shows an increase in integrated backscatter and loss of cardiac cycle-dependent variation in backscatter. The cyclic variation of backscatter is closely related to regional myocardial contractile function; the latter is a marker of myocardial ischemia. The present study was designed to test the hypothesis that intramural cyclic variation of backscatter can map and estimate infarct size. METHODS AND RESULTS: Transmural myocardial infarction was produced in 12 anesthetized, open-chest dogs by total occlusion of the left anterior descending coronary artery for 4 hours. A real-time ultrasonic tissue characterization instrument, which graphically displays integrated backscatter Rayleigh 5, cardiac cycle-dependent variation, and patterns of cyclic variation in backscatter, was used to map infarct size and area at risk of infarction. Staining with 2,3,4-triphenyltetrazolium chloride (TTC) and Patent Blue Dye was used to estimate infarct size and the area at risk, respectively. The ratio of infarct size to area at risk of infarction determined with UTC correlated well with that determined with TCC (r = 0.862, y = 23.7 +/- 0.792x). Correlation coefficients for infarct size and area at risk were also good (r = 0.736, y = 12.3 +/- 737x for infarct size and r = 0.714, y = 5.80 +/- 1.012x for area at risk). However, UTC underestimated both infarct size and area at risk. CONCLUSIONS: Ultrasonic tissue characterization may provide a reliable, noninvasive method to estimate myocardial infarct size.

Animals↗
PubMed1991

Characterization of a 67-kDa S6 protein kinase from rat liver.

Fractionation of rat liver cytosol on DEAE-cellulose resolved two S6 kinases eluting at 25 mM KCl (peak I) and 100 mM KCl (peak II). The apparent molecular weights of the peak I and peak II kinases are 26,300 and 67,000, respectively. The peak II kinase was further purified and characterized. Incubation of the kinase with [gamma-32P] ATP and Mg2+ resulted in the incorporation of 32P predominantly into a 67-kDa band. Optimal activity of the kinase was observed in the presence of 5 mM Mg2+ and in the pH range of 8.0-8.5. The Km for ATP and 40S subunit were 7.3 microM and 1.5 microM, respectively. The Mg(2+)-stimulated kinase activity was inhibited by various divalent metals, NaF, and polyamines. The properties of the peak II S6 kinase are very similar or identical to the previously described mitogen-activated S6 protein kinase and may represent the nonactivated form of this enzyme.

Animals↗
PubMed1991

Prenatal protocol usage.

A review was conducted of 825 obstetrics cases on active computer file at the Department of Family and Community Medicine in Little Rock, Arkansas. Independent raters evaluated faculty and resident usage of a prenatal protocol which was routinely used as a teaching tool in the department's residency program since 1972. Significant differences were found to exist with regard to usage of the tool by physician status. Faculty were more consistent and thorough in their usage of the teaching tool when compared to residents. Differences were explained in terms of a practice effect, research bias of faculty, levels of practice, and potential weaknesses in the educational program.

Clinical Protocols↗
PubMed1990

Antibodies to fibronectin bind to plaques and other structures in Alzheimer's disease and control brain.

Antibodies to fibronectin (Fn) bind not only the basal lamina in Alzheimer's disease brain, but also crystal-like formations in the grey matter, senile plaques, a subset of neuronal perikarya, and large highly processed stellate formations which were both neurofilament and glial fibrillary acidic protein (GFAP) negative and which were identified at a lower frequency in non-demented control brains.

Alzheimer Disease↗
PubMed1990

Rare or unusual causes of chronic, isolated, pure aortic regurgitation.

Six patients undergoing aortic valve replacement had rare or unusual causes of isolated, pure aortic regurgitation. Two patients had congenitally bicuspid aortic valves with a false commissure (raphe) displaced to the aortic wall ("tethered bicuspid aortic valve"), two had floppy aortic valves, one had a congenital quadricuspid valve, and one had radiation-induced valve damage.

Adult↗
PubMed1990

Tomographic views of normal and abnormal hearts: the anatomic basis for various cardiac imaging techniques. Part I.

Recent developments have taken place in the diagnosis of cardiovascular disorders in the area of cardiac imaging techniques. From a previous era of imaging by silhouettes (chest roentgenography, fluoroscopy, angiocardiography), we have emerged into an era of imaging by tomographic scanning (echocardiography, radionuclide tomography, computed tomography, magnetic resonance). A basic understanding of tomographic cardiac anatomy is the foundation for proper use and interpretation of these new imaging modalities. The present report provides a description of the techniques of tomographic cutting of necropsy cardiac specimens and illustrates some of the pathologic cardiac abnormalities cut in these tomographic planes. Part I of this report describes position of the heart and tomographic axis planes, preparation of the heart and methods of cutting at necropsy, and the short-axis, two-chamber, and four-chamber views of the heart.

Heart↗