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Biomedical subjects

D J Howard

Publications and source records attributed to D J Howard.

71 records · Page 4Linked to original sources
PubMed1983

The response of special education students to an activity-centered health curriculum.

The study's purpose was to assess the effectiveness of an activity-centered health education curriculum designed for regular students on the general health beliefs of special education students. As part of an entire school system evaluation, 92 Learning Disability students and 142 Learning Limitation students were randomly assigned to experimental and control groups. All the students were pretested and subsequently posttested using a 28-item questionnaire based on the Health Belief Model. The analysis of covariance indicated that the activity-centered health education program apparently was effective among the Learning Disability students, but was not effective among students with IQ scores of 80 or below.

Attitude to Health↗
PubMed1983

CT evaluation of paranasal sinus tumours for cranio-facial resection.

Twenty-two patients with tumours of the paranasal sinuses had computerised tomography performed prior to cranio-facial resection. The findings of CT, histology and operative appearances are compared and a 78% correlation found. The radical approach offered by cranio-facial resection allows more accurate confirmation of CT findings than hitherto possible. The particular importance of CT scanning in relation to tumours of paranasal sinuses is discussed.

Brain Neoplasms↗
PubMed1982

Asialoglycoprotein receptors in hepatic regeneration.

The hepatic binding protein which is responsible for receptor-mediated endocytosis of desialylated glycoproteins undergoes cell-cycle dependent modulation of its expression. Endocytosis of desialylated orosomucoid by hepatocytes isolated from regenerating liver following two-thirds hepatectomy is reduced by 80% and returns to normal when regeneration is substantially complete. This decrease in endocytotic activity is due to selective loss of cell-surface associated receptor during liver regeneration.

Animals↗
PubMed1982

Genetic control of hexokinase variation in insects.

Hexokinase variation in insects appears to be under the control of a single locus in some species and under multiple-locus control in others. It is often difficult to distinguish the number of loci controlling hexokinase expression. Analysis of hexokinase electrophoretic patterns in six species of mosquitoes and five species of crickets, as well as a review of hexokinase variation in other insect species, is used to emphasize the importance of interspecific comparisons when making genetic inferences. Evidence is provided which adds support for multiple hexokinase loci in dipterans. Hexokinase control by multiple loci may be difficult to determine in some species because of tight linkage, disequilibrium, and/or posttranslational modification.

Animals↗
PubMed1982

Evaluation of an activity-centered health curriculum: assessment of cognitive knowledge.

This study was to determine how effective an activity-centered health curriculum was in providing health information to fourth, fifth and sixth-grade students in the Canton City school system. The assessment was facilitated by a posttest-only research design. Ten schools were randomly selected to receive a new health program, as compared to a control group of 10 schools which did not. Results indicated that the experimental students achieved significantly higher posttest cognitive knowledge mean scores than the control students. These findings were sustained for each grade level after adjusting for group differences in reading ability.

Child↗
PubMed1980

Functional segregation of hepatic receptors for asialoglycoproteins during endocytosis.

To examine whether hepatic plasma membrane receptors for asialoglycoproteins are replaced or reutilized during endocytosis, receptors on the surface of isolated hepatocytes were uniquely labeled by neuraminidase treatment. This enzyme abolishes binding of asialo-orosomucoid, a galactose-terminated glycoprotein, and restricts the ligand specificity of the cell surface receptor protein to N-acetylgalactosamine-terminated glycoproteins such as desialylated ovine submaxillary mucin. Although a much larger intracellular pool of apparently identical receptor protein is unaffected by neuraminidase, endocytosis of asialo-orosomucoid does not occur in neuraminidase-treated cells, while endocytosis of desialylated ovine submaxillary mucin is unaffected. Endocytosis of desialylated ovine submaxillary mucin, in amounts far exceeding cell surface binding capacity, is not a consequence of replacement of neuraminidase-treated surface receptor by intracellular receptor. Binding and endocytosis of asialoglycoproteins appear, therefore, to be maintained through a continuous reutilization of plasma membrane receptors rather than through their replacement from an intracellular receptor pool.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging of paranasal sinus tumors for craniofacial resection.

Computerized tomography (CT) has been shown to be 78% accurate with respect to anatomic extent of tumor when correlated with operative findings and histology in patients undergoing craniofacial resection. To determine whether preoperative evaluation could be improved by the combination of CT and magnetic resonance imaging (MRI), 26 patients with tumor of the paranasal sinuses had undergone MRI before surgery in addition to CT. Ten patients also received Gadolinium-DTPA as a contrast-enhancement agent during MRI. The radical approach offered by craniofacial resection allows accurate evaluation of imaging techniques and when these are compared with histologic findings, a 94% correlation is found. The use of Gadolinium further improves the accuracy of tumor delineation to 98%. Despite the intrinsic disadvantage of absent bone detail, MRI demonstrates the extent of tumor better than CT and can distinguish it from inflammed mucosa, retained secretions, and normal mucosa provided the correct sequences are used.

Adolescent↗
PubMedDate not supplied

Craniofacial resection for tumors of the nasal cavity and paranasal sinuses.

The craniofacial approach for resection of tumors of the nose and paranasal sinuses is well established, as are its advantages over previous methods of treatment. The technique has been considerably modified, resulting in an operation that combines excellent access, a sound oncologic resection with excellent cosmesis, and low postoperative morbidity for conditions associated hitherto with an extremely poor prognosis. The 7-yr experience of 60 patients is presented. Results suggest improved survival in a group of patients who are potentially curable by this procedure, while in those with extensive disease good palliation is achieved. In addition, large benign tumors that would previously have been considered inaccessible can be resected. Its many advantages recommend it as the treatment of choice for tumors of the nose and paranasal sinuses.

Adenocarcinoma↗
PubMedDate not supplied

The nature of the collagen in hepatic fibrosis in advanced murine schistosomiasis.

Livers from CF 1 mice infected with Schistosoma mansoni, 50 cercariae each, were examined 8 weeks postinfection. The collagen content of the livers was increased about 18-fold over that for normal control animals. Quantitation of the collagen types in pepsin-solubilized collagen showed a change in the ratio of Type I to Type III from 2:1 in normal mice to 1:1 in the fibrotic animals. The change in ratio resulted from a very large accumulation of Type III collagen and, accordingly, may provide an important model for study of the possible reversibility of fibrotic lesion.

Amino Acids↗
PubMedDate not supplied

Gene exchange in a ground cricket hybrid zone.

The ground crickets Allonemobius fasciatus and A. socius (Orthoptera: Gryllidae) are sister species that form a mosaic hybrid zone in the eastern United States. The genetic structure of the hybrid zone has been studied extensively by the use of protein electrophoresis. Here, we report the discovery of several random amplification of polymorphic DNA (RAPD) markers that distinguish the two species, and we assess the congruence of RAPD markers and protein markers with regard to the identification of hybrids in mixed populations. Both sets of markers indicate that gene flow between A. fasciatus and A. socius is quite limited.

Animals↗
PubMedDate not supplied

A treatment algorithm for the management of epistaxis in hereditary hemorrhagic telangiectasia.

We examined the management options used for epistaxis of varying severity in patients with hereditary hemorrhagic telangiectasia (HHT) to develop a treatment algorithm. Fifty patients with HHT were studied from 1991 to 1997 to consider various treatment options and their relative efficacy. There were 28 females and 22 men; their ages ranged from 15 to 85. Follow-up ranged from 6 months to 6 years. A wide variety of treatments had been used (including various forms of cautery, septal surgery, topical and systemic hormones, antifibrinolytic therapy, arterial ligation, laser therapy, and closure of the nostrils). Treatments used during the follow-up period were argon laser therapy (40), systemic estrogen or progesterone (17), septodermoplasty (12), or closure of the nostrils (14). Patients were divided into those with mild to moderate disease (requiring one or no blood transfusions during the course of their illness) and those with severe disease (requiring more than one blood transfusion). Using this broad categorization, those with mild to moderate disease did well with sequential argon laser therapy with or without the adjunct of septodermoplasty or hormone therapy. Those with severe disease did not find argon laser therapy beneficial but found their epistaxis completely stopped with closure of the nasal cavities. Based on these findings, a simple treatment algorithm defines the optimum treatment options for epistaxis in this difficult-to-treat group of patients.

Adolescent↗