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Biomedical subjects

C C Brown

Publications and source records attributed to C C Brown.

At least 73 records · Page 4Linked to original sources
PubMed1994

Presence of African horse sickness virus in equine tissues, as determined by in situ hybridization.

In a retrospective study, a negative-sense digoxigenin-labeled RNA probe, corresponding to the gene encoding nonstructural protein-1 of African horse sickness virus (AHSV) serotype 4, was applied to formalin-fixed, paraffin-embedded tissue taken from horses in the terminal stages of infection with AHSV. Fifteen infected ponies and one noninfected control were studied. Ponies exhibited a range of clinical signs and lesions. Thirteen ponies were infected with serotype 4, one with serotype 1, and one with serotype 2. Ponies were monitored clinically and euthanatized when severely clinically ill. The following tissues were available for study by in situ hybridization and histopathology: lung, heart, spleen, neck muscle, and supraorbital fat. Histologically, the most striking changes were pulmonary edema and, in some, acute myocardial necrosis. In situ hybridization revealed virus distributed widely in sections of lung and heart examined, with relatively less in spleen, neck muscle, or supraorbital fat. Virus was localized to target cells with morphologic features compatible with endothelium in all organs except spleen, where it was found in both endotheliumlike cells and large mononuclear cells.

African Horse Sickness↗
PubMed1994

Identification of African horse sickness virus in cell culture using a digoxigenin-labeled RNA probe.

A digoxigenin-labeled RNA probe was synthesized from a plasmid containing a portion of the African horse sickness virus (AHSV) serotype 4 genome segment coding for nonstructural protein 1. In an in situ hybridization procedure, this probe hybridized successfully to Vero cells infected with each of the 9 serotypes of AHSV. There was no hybridization with noninfected cell cultures or cell cultures infected with bluetongue virus.

African Horse Sickness Virus↗
PubMed1994

Who participates in cardiovascular disease risk factor screenings? Experience with a religious organization-based program.

Adult members who declined participation in cardiovascular disease risk factor screenings offered at religious organizations were randomly selected and asked to participate in screenings at their homes. Relationships between screening participation and sociodemographic, behavioral, and physiological measures were examined. Age, knowledge of cardiovascular disease risk factors, body mass index, current smoking status, previous report of elevated blood pressure, current diastolic blood pressure measurement, frequency of worship service attendance, and residential distance from the religious organization screening site were important predictors of screening response. Those with conspicuous risk factors appeared less likely to initially respond to religious organization site screening invitations.

Adult↗
PubMed1993

Saturated fat intake and lung cancer risk among nonsmoking women in Missouri.

BACKGROUND: Although the vast majority of lung cancer cases in women are caused by smoking, 9%-20% of cases occur in nonsmokers. Previous epidemiologic research on the relationship between lung cancer and diet has shown that fruit and vegetable consumption may confer a protective effect against lung cancer, while a diet rich in cholesterol and fat may increase risk. PURPOSE: The purpose of this case-control study was to examine the effects of a broad range of dietary factors on the risk of lung cancer in a population of nonsmoking white women 30-84 years of age. METHODS: A telephone-administered questionnaire was used to determine and/or verify eligibility with regard to age, gender, race, and smoking status. In a second interview at the participant's home, a widely used food frequency questionnaire was filled out, and logistic regression was subsequently used to analyze the responses. We obtained dietary information on 429 case subjects who had a diagnosis of lung cancer reported to the Missouri Cancer Registry between June 1, 1986, and June 1, 1991, and 1021 control subjects. If a case subject had died or was too ill to be interviewed, next-of-kin familiar with the woman's diet were interviewed instead. Of the 429 women with lung cancer, 211 (49%) had lung adenocarcinoma. RESULTS: A strongly increasing trend in lung cancer risk was observed with increased saturated fat consumption among these non-smoking women; the relative risk was more than sixfold greater for the highest quintile of consumption than for the lowest quintile. The effect of saturated fat was more pronounced for adenocarcinoma than for other cell types. Weekly servings of beans and peas were significantly related to decreased lung cancer risk, while citrus fruit and juice showed a twofold increase in risk; this trend was also significant. CONCLUSION: By focusing on non-smoking women with lung cancer, including a large number with adenocarcinoma, we observed a clear association with saturated fat consumption that may have been masked in earlier studies of lung cancer involving a high percentage of smokers.

Adult↗
PubMed1993

Interpretation of energy adjustment models for nutritional epidemiology.

The authors discuss the interpretation of three alternative energy adjustment models for nutritional epidemiology. It is shown that four different effects are addressed by these models: 1) adding nutrient N, 2) substituting nutrient N for "other" nutrients, 3) adding "other" nutrients, and 4) adding both N and "other" nutrients in a specific ratio. Each of these effects may be estimated from any of the three models. The relative standard errors for the four estimated effects are also provided.

Diet↗
PubMed1993

Use of a digoxigenin-labeled RNA probe to detect all 24 serotypes of bluetongue virus in cell culture.

A digoxigenin-labeled RNA probe, corresponding to the section of the bluetongue virus (BTV) serotype 17 genome coding for nonstructural protein-1 (NS1), was applied to noninfected cell cultures and cell cultures infected with 24 different serotypes of BTV, 2 serotypes of epizootic hemorrhagic disease virus, and African horse sickness virus type 4. The probe hybridized to all cell cultures infected with the various BTV serotypes but did not hybridize to noninfected cell cultures or cell cultures infected with any of the other orbiviruses.

Animals↗
PubMed1993

Statistical analysis of animal cancer chemoprevention experiments.

We explore the use of a statistical model proposed by Kokoska (1987, Biometrics 43, 525-534) for the analysis of animal cancer chemoprevention experiments. We show, using an example, that the results derived from the method can be sensitive to the parametric forms of the distributions that are assumed, particularly to the distribution of the number of tumors per animal. We propose goodness-of-fit tests to aid in the choice of the distributions.

Adenocarcinoma↗
PubMed1992

CD34+ bone marrow cells are infected with HIV in a subset of seropositive individuals.

Individuals infected with HIV frequently develop cytopenias and suppressed hematopoiesis. The role of direct HIV infection of hematopoietic progenitor cells in this process has not been defined. In this study, purified CD34+ bone marrow progenitor cells from 74 Zairian and American patients were studied by both coculture viral isolation and polymerase chain reaction for evidence of HIV infection. A total of 36.5% of Zairian and 14% of American patients had HIV infection of the CD34+ cell subset, with as many as 1 in 500 CD34+ cells infected. Most of the Zairian patients in this study had advanced HIV infection and markedly decreased CD4/CD8 T lymphocyte ratios (mean 0.160 +/- 0.08), and no laboratory value predicted the presence of infection in the CD34+ subset of a given Zairian individual. In contrast, American patients with CD34+ cell infection had total CD4 cells less than 20/mm3 and a greater decrease of the CD4/CD8 T lymphocyte ratio compared to seropositive Americans without CD34+ cell infection (p = 0.003). Hematopoiesis, studied by methylcellulose colony assays, was depressed in all seropositive patients studied with no significant further suppression when CD34+ cells were infected. Thus, CD34+ bone marrow progenitor cells are infected in vivo in a subset of seropositive individuals and may serve as an additional reservoir of virus in HIV-infected individuals.

Adult↗
PubMed1992

Quantitative method for comparison of skeletal muscle architectural properties.

A numerical method is presented which calculates the architectural difference index between two muscles. This index is based upon the parameters, identified using statistical discriminant analysis, which best characterize the various muscles. This index can be used to reduce multiple architectural properties into a single value and may be useful in selecting donor muscles which are required to perform a substitute function for another muscle which has been lost or injured.

Animals↗
PubMed1992

A pathogenesis study of highly pathogenic avian influenza virus H5N2 in chickens, using immunohistochemistry.

Eighteen specific pathogen-free chickens (nine hens older than 1 year and nine 15-week-old males) were inoculated with highly pathogenic avian influenza virus A/Chicken/Pennsylvania/1370/1983 (H5N2). Birds were serially killed and tissues collected for histological and immunohistochemical evaluation. In the group of older hens, disease was acute or peracute. By immunohistochemistry, antigen was abundant in capillary endothelium in multiple organs, and staining for antigen in parenchymal cells was marked in brain and heart. In the group of younger male birds, disease was subacute. Immunohistochemical staining of capillary endothelium was less pronounced and viral antigen staining was evident in the parenchymal cells of the heart, brain and kidney.

Animals↗
PubMed1992

Plasma lipid and lipoprotein concentrations of men consuming a low-fat, high-fiber diet.

This study assessed the influence of a low-fat, high-fiber diet on blood lipid concentrations of 42 men with desirable or moderately elevated cholesterol concentrations. A low-fat diet (19% fat, 4% saturated fatty acids, 4.6 g fiber/MJ) was compared with a high-fat diet (41% fat, 15% saturated fatty acids, 2.0 g fiber/MJ) and with subjects' self-selected diets. Substituting the low-fat for the high-fat diet decreased total, low-density-lipoprotein, and high-density-lipoprotein cholesterol by 17-20%. Lipid changes between 6 and 10 wk were minor. A reduction in plasma cholesterol of greater than 0.52 mmol/L was achieved with the low-fat diet in 59% of men changing from their self-selected diets and in 79% changing from the high-fat diet. Percent reduction was independent of subjects' cholesterol classification. Results indicate that significant reductions in plasma cholesterol can be achieved by the majority of men committing to a low-fat, high-fiber diet.

Adult↗
PubMed1992

An epizootic of malignant catarrhal fever in a large captive herd of white-tailed deer (Odocoileus virginianus).

Over a 4-mo period 23 of 28 white-tailed deer kept at a small zoo in New Jersey (USA) died. Clinical signs prior to death were minimal and consisted of depression, central nervous system disorders, and watery diarrhea in a few animals only. Histopathology revealed widespread acute vascular lesions, ranging from modest accumulations of blast-like mononuclear cells and edema in the adventitia through to disruption of the tunica media and thrombosis. These vascular lesions were seen in a variety of organs but were most prominent in lung, heart, liver and intestine. Severe vascular changes were associated with necrosis. Lymphoreticular hyperplasia was evident in the lymphoid tissue of all animals.

Animals↗
PubMed1992

A pathogenesis study of foot-and-mouth disease in cattle, using in situ hybridization.

Eight calves were exposed in an aerosol chamber to nebulized foot-and-mouth disease virus. Two control animals were exposed in a similar manner to cell culture media only. Animals were euthanized at intervals and various tissues examined by in situ hybridization using a biotinylated RNA probe corresponding to a portion of the viral gene coding for the polymerase enzyme. By this technique large amounts of viral nucleic acid were found in coronary band, interdigital cleft and tongue as early as six hours postexposure, indicating a very rapid delivery from the portal of entry to the predilection sites for lesion development. This occurred well before the onset of viremia which by virus isolation was not detectable until 30 hours postexposure. The in situ hybridization signal in these tissues decreased in intensity and extent with time to focally positive areas, occasionally surrounding a vesicle. Other epidermal sites not normally thought of as sites for foot-and-mouth lesion development, such as carpus and eyelid, also had some viral nucleic acid detectable at various time intervals. In the lung by in situ hybridization, alveolar septa had viral nucleic acid early in infection (6-18 h postexposure) while later (36-96 h postexposure), the in situ hybridization signal was prominent in alveolar macrophages.

Animals↗
PubMed1991

Unique human neutrophil populations are defined by monoclonal antibody ED12F8C10.

A mouse IgG1 monoclonal antibody ED12F8C10 (C10) binds a constant percentage of peripheral blood neutrophils in the same individual when studied over time, defining a distinct subset of neutrophils in all normal individuals studied to date. Bone marrow studies confirm that the heterogeneity is present to the same degree at all stages of neutrophil development from the myelocyte to the mature neutrophil. Neither in vivo nor in vitro activation of neutrophils explains or significantly alters the relative percentages of C10-positive and -negative neutrophils in the same individual. With both activation and exudation, however, expression of the C10-defined epitope increases in intensity in the C10 binding subpopulation. Studies of NBT reduction, phagocytosis, adherence, light scattering characteristics, and monoclonal antibody surface binding have failed to demonstrate physical or functional differences between the C10-defined populations. We examined C10 binding in patients with different defects of phagocyte function. In two patients with neutrophil-specific granule deficiency, less than 1% of the neutrophils were found to be C10 positive, while neutrophils from a patient with idiopathic leukemoid reaction and recurrent infections demonstrated greater than 99% C10 binding. Although the present study does not delineate the physiologic significance of C10 binding heterogeneity, it firmly supports the concept of neutrophil heterogeneity at the level of surface antigen expression.

Antibodies, Monoclonal↗
PubMed1991

An immunohistochemical study of the pneumonia caused by peste des petits ruminants virus.

Ten goats were inoculated with peste des petits ruminants virus, a paramyxovirus closely related to rinderpest virus. All goats developed severe clinical disease, 8/10 having coughing or dyspnea as prominent clinical signs. In addition, all of the goats had stomatitis and diarrhea. Histopathologic and immunohistochemical studies were done only on the respiratory tracts. Pathologic changes ranged from mild multifocal bronchiolitis and bronchitis to severe bronchointerstitial pneumonia. Lesions were more severe in anteroventral than caudal lobes. The histologic nature of the viral process in the goat lungs had many features in common with the processes of pneumonia in dogs, due to canine distemper, or pneumonia in human beings, due to measles virus. Immunohistochemical staining of formalin-fixed, paraffin-embedded respiratory tract tissue was performed using an indirect system with rabbit anti-rinderpest virus serum, biotinylated anti-rabbit antibody, streptavidin-alkaline phosphatase, and nitroblue tetrazolium chromogen. Staining was sensitive, highlighting the presence of viral antigen in both lung and trachea of all goats. Viral antigen was found in both cytoplasm and nucleus of tracheal, bronchial, and bronchiolar epithelial cells, type II pneumocytes, syncytial cells, and alveolar macrophages. In general, the amount of staining correlated directly with the severity of the inflammatory process.

Animals↗
PubMed1991

A preliminary study of the pathogenesis of foot-and-mouth disease virus using in situ hybridization.

Five adult guinea pigs were inoculated intraepithelially in the right hindfoot pad with foot-and-mouth disease virus. Animals were euthanatized with carbon dioxide at 4, 10, 24, 48, and 72 hours post-inoculation. Generalized disease developed in the guinea pigs, as evidenced by depression and inappetance by 24 hours post-inoculation and by the formation of vesicles in the noninoculated hindfoot pad by 48 hours post-inoculation. By in situ hybridization, using a 500 base pair biotinylated RNA probe, viral nucleic acid was detected in the noninoculated fore- and hindfoot pads as early as 10 hours post-inoculation, well before any pathologic changes associated with foot-and-mouth disease virus infection were detected. These tissues remained consistently positive for the presence of viral nucleic acid up to the end of the experiment. At this time, in the forefoot pad, even though virus had first been detected with certainty in that tissue 62 hours previously, there was still no microscopic evidence of foot-and-mouth disease virus-induced damage in the histologic section. Similarly, tongue tissue was positive by in situ hybridization at 4, 48, and 72 hours post-inoculation, yet there was never any microscopic evidence of degeneration or vesicle formation. From this preliminary study, it appears that, in the guinea pig, the virus is widely disseminated to foot pads and tongue, with epidermal lesions resulting only in selected areas.

Animals↗