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Biomedical subjects

J Roach

Publications and source records attributed to J Roach.

32 records · Page 2Linked to original sources
PubMed1988

Cellular distribution of c-myc transcripts during chemical hepatocarcinogenesis in rats.

The expression of cellular myc (c-myc) was studied during early and late stages of chemical hepatocarcinogenesis in the rat using Northern blot analysis and in situ hybridization. Hepatocarcinogenesis was induced according to the resistant hepatocyte model of Solt and Farber. An uninitiated version of this model was also used to examine the expression of c-myc during proliferation and differentiation of oval cells. The expression of c-myc was increased throughout hepatocarcinogenesis starting with early preneoplastic foci and oval cells. Similar levels of c-myc transcripts were detected in oval cells and basophilic hepatocytes generated by the uninitiated version of the protocol as were found in preneoplastic foci and oval cells during hepatocarcinogenesis. Whereas c-myc expression remained elevated in late neoplastic nodules and carcinomas, it gradually declined in both "remodelling" nodules and uninitiated livers. Our data indicate that c-myc expression is elevated during the undifferentiated stages of hepatocyte development. Furthermore, the data support the hypothesis that a critical early step in chemical hepatocarcinogenesis involves a block in the normal differentiation program of the hepatocytes.

Animals↗
PubMed1987

Anhydrous pill ingestion: a new cause of esophageal obstruction.

We report the case of a patient who presented with complaints of abdominal discomfort and recurrent vomiting after ingestion of an anhydrous protein pill. Esophagoscopy revealed the presence of a pill much larger than initially ingested. The pill was removed through the endoscope. This is the first report of esophageal obstruction from anhydrous pill ingestion.

Adult↗
PubMed1987

Lumbar Scheuermann's. A clinical series and classification.

Scheuermann's disease of the thoracic spine is a well-defined entity, although its exact etiology is unknown. In the thoracolumbar or lumbar spine however, the criteria are much less strict for the application of this eponym. A retrospective review of all the cases of lumbar Scheuermann's disease seen at the Texas Scottish Rite Hospital revealed two distinct radiographic pictures. These consisted of a "classic" Scheuermann's and an "atypical" type characterized by vertebral end plate changes, disc space narrowing, and anterior Schmorl's nodes, but not otherwise fulfilling Sorenson's criteria. This group tended to occur in more athletic adolescents or those with a history of increased axial stress to the spine. A subgrouping of atypical Scheuermann's disease is proposed and includes acute traumatic intraosseous disc herniation. Based on these findings, a classification of lumbar Scheuermann's disease is proposed.

Adolescent↗
PubMed1986

Progressive change in lymphocyte distribution and degree of hypergammaglobulinemia with age in children with hemophilia.

Fifty asymptomatic, pediatric hemophiliacs were examined for distribution of T-cell subsets, responsiveness to mitogen stimulation, interleukin-2 production, hypergammaglobulinemia, and the presence of antibody to virus including the human T-lymphotrophic virus type III (HTLV-III). Hemophilia A patients receiving factor VIII concentrate as replacement therapy had the most pronounced changes including decreased T4/T8 ratios and lower in vitro responsiveness to both phytohemagglutinin and pokeweed mitogen. Hemophilia A patients treated with cryoprecipitate and hemophilia B patients did not demonstrate these changes. Regardless of replacement therapy, hemophiliacs demonstrated a progressive decrease in the T4/T8 ratio and a progressive increase in the degree of IgG hypergammaglobulinemia as they aged. The amount of factor or cryoprecipitate or exposure to virus did not influence the T4/T8 ratio. These changes appear to be a result of chronic product exposure, which becomes more pronounced with increasing age.

Acquired Immunodeficiency Syndrome↗
PubMed1986

HTLV-III status and abnormalities in T lymphocyte distribution in children with hemophilia A.

Children with hemophilia A are at risk for the acquired immunodeficiency syndrome (AIDS). Clinically asymptomatic hemophiliacs demonstrate many immune abnormalities that might represent exposure to the AIDS agent through blood products or be a natural reaction to their therapy. In this study, we examined lymphocyte subset distribution in children with hemophilia A who had been exposed to HTLV-III as determined by antibody seroconversion. Seroconversion to HTLV-III was confirmed using Western blot analysis. The lymphocyte subsets studied included T4+ and T8+ cells. The distribution of lymphocyte subsets in children with hemophilia A was independent of seroconversion to HTLV-III. Children with hemophilia A treated with commercial factor VIII concentrate had normal numbers of circulating T4+ lymphocytes and significantly increased numbers of circulating T8+ lymphocytes compared with their nontransfused age-matched counterparts. An increased number of T8+ lymphocytes was not observed, however, in children treated exclusively with cryoprecipitate. These results suggest that HTLV-III alone cannot account for changes in lymphocyte subsets in hemophiliacs. Higher antigenic protein loads in factor VIII concentrate or additional factors might account for the increased absolute numbers of T8+ lymphocytes and represent a natural response to therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1985

An expert system for information on pharmacology and drug interactions.

Pharmacological information has been organized and encoded in rules and frames for systematic retrieval. This includes: delineation, definition, and hierarchical subdivision of mechanisms responsible for drug interactions; division of pharmacological agents into a hierarchy of subclasses to allow for defining interacting drugs by classes as well as by specific agents; correlation of drug classes and specific drugs with mechanisms by which they may be involved in drug interactions. This information, accessible through a natural language-like and menu driven interface, allows clinicians to know what may happen when two drugs are used together, why, what can be done to alleviate detrimental interactions, and what related drugs may also be involved in similar interactions.

Drug Information Services↗
PubMed1984

Cognitive, perceptual, and personal-social development of prematurely born preschoolers.

This study was designed to determine possible differences in the cognitive, perceptual, and personal-social development of prematurely and maturely born 3-yr.-olds which might foreshadow later learning problems. The subjects were 40 prematurely born graduates of a neonatal intensive care unit (birth weight less than 2,500 gm, less than 37 wk. gestation) matched on the pair-level with full-term controls on sex, race, post-conceptual age, and socioeconomic background. All subjects were singletons and parity was matched at the group level. No differences were found between the groups on tests of higher mental processes including the General Cognitive, Verbal, Quantitative, and Memory Scales of the McCarthy Scales of Children's Abilities, and researcher-devised measures of problem-solving competence. No differences in parental reports of personal-social development were noted. Prematures did not perform as well as controls on perceptual performance tasks, and this difference was interpreted as reflecting relatively impaired visual-motor coordination.

Child, Preschool↗
PubMed1983

The morphogenesis of cell hairs on Drosophila wings.

We describe in this paper details of morphogenesis of wing hairs in Drosophila pupae. The ultimate objective is to relate specific protein components used in hair construction to specific components produced in the rapidly changing patterns of gene expression that are characteristic for the period of hair differentiation in wing cells (H. K. Mitchell and N. S. Petersen, 1981, Dev. Biol. 85, 233-242). Hair extrusion to essentially full size occurs quite suddenly at about 34 hr (postpupariation) and this is followed by deposition of a double-layer of cuticulin during the next 4 to 5 hr. Extreme changes in shape of cells and hairs, probably related to actin synthesis, then occur for the next 5 to 6 hr. Deposition of fibers within the hairs and on hair pedestals follows. Formation of cuticle on the cell surface begins and continues until some time in the 60-hr range. It appears that cuticle is formed only on the cell surface and not in hairs or on the top of hair pedestals. The protein synthesis patterns associated with these events are described.

Animals↗
PubMedDate not supplied

A trial of church-based smoking cessation interventions for rural African Americans.

BACKGROUND: The Alliance of Black Churches Health Project was begun in an effort to address the health problems of the African-American residents of two rural Virginia counties. Smoking cessation was chosen as the principal target behavior in one county. Church coalitions were chosen as the principal organizations through which to implement the interventions. METHOD: A smoking cessation program was designed that combined one-on-one counseling with self-help materials and community-wide activities. To provide these services, up to two smoking cessation counselors were trained from participating churches. To evaluate the impact, population-based cohorts of smokers were assembled in each county using a door-to-door survey. Respondents were recontacted after 18 months. Smoking cessation (1-month continuous abstinence), stages of change, and exposure to the interventions were assessed. RESULTS: The overall smoking prevalence at baseline was 25.8%. At follow-up, the smoking cessation rate in the intervention county was 9.6% and in the control county 5.4% (P = 0.18). Among those attending church once a month or more, the respective quit rates were 10.5% and 5.9% (P = 0.20). There was significantly more progress along the stages of change in the intervention than in the control county. There was also higher awareness of and contact with smoking cessation programs in the former compared with the latter. CONCLUSION: Smoking cessation interventions for African Americans can be successfully implemented through a church coalition. The interventions were associated with significant progress along the stages of cessation. Although the quit rate was higher in the intervention community, the difference was not significant.

Adult↗
PubMedDate not supplied

The large-scale isolation of bryostatin 1 from Bugula neritina following current good manufacturing practices.

A novel process was designed for the large-scale isolation of bryostatin 1 from the bryozoan Bugula neritina L. in order to obtain multigram quantities of highly pure material for formulation studies, preclinical toxicology, and clinical trials in cancer patients. Multigram quantities of bryostatin 1 were obtained from a collection of approximately 10,000 gallons of wet animal. A phorbol dibutyrate (PDBu) receptor binding assay and hplc with photodiode array detection were used for the design, validation, and control of the isolation process.

Animals↗
PubMedDate not supplied

The community ecology of diabetes patient classification and practice characteristics.

We examined the clinical and epidemiologic characteristics of diabetic subjects ascertained from five different sources (hospital, private practice, specialist practice, nursing home, and prevalence survey) in a medium-sized upstate New York community. Patients were categorized using the National Diabetes Data Group classification (based on weight and insulin requirement) and using an alternative clinical classification scheme based on age at onset and insulin use. Both classifications demonstrate marked differences in the distribution of diabetic subjects. Those seen in general medical practice reflect the prevalent population and tend to have fewer complications and less insulin requirement. Those seen in specialist practice or in hospital have higher complication frequencies. Thus, the source of patients may determine the epidemiologic picture of the disease, as well as the practitioners' perceptions. Use of the clinical classification scheme helps to identify a subgroup of diabetic subjects--those with onset past the age of 25 yr who use insulin--at greatest risk of complications. Further investigation of high-risk groups is warranted, particularly for the implementation and evaluation of diabetes control programs.

Adolescent↗