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Biomedical subjects

J C Chang

Publications and source records attributed to J C Chang.

At least 163 records · Page 9Linked to original sources
PubMed1990

Tobacco smoke suppresses T cells but not antigen-presenting cells in the lung-associated lymph nodes.

Chronic inhalation of cigarette smoke in mice preferentially inhibited the antigen-specific T-cell proliferative response of lung-associated lymph nodes compared to anatomically distant lymph nodes. Cell mixing experiments demonstrated that the defect in smoked mice resulted from an abnormality in T-lymphocyte function. In contrast, the activity of antigen-presenting cells was similar in smoked and sham-smoked control animals. These results suggest that T-cell function in lung-associated lymphoid tissue may be inhibited in smokers, leading to a localized predisposition to respiratory tract infections.

Animals↗
PubMed1990

Disseminated intravascular coagulation due to intravenous administration of hetastarch.

Disseminated intravascular coagulation occurred in a patient after intravenous administration of hetastarch. The onset was acute within 3 hours after exposure to the agent and the course was fulminating. The patient died in 48 hours. Clinical, hematologic, and pathologic features are presented and possible pathophysiologic mechanism is discussed. In view of this experience and documented effects of hetastarch on coagulation, the use of hetastarch should be avoided if the patient has a history of coagulation disorder, and the patient receiving the agent should be closely monitored with appropriate coagulation tests.

Adult↗
PubMed1990

An analysis of occupational risks for brain cancer.

We evaluated the risks of brain cancer in relation to employment history in a case-control study of 312 cases and 1,248 cancer controls. Subjects were identified through the Missouri Cancer Registry for the period 1984 through 1988. Job classification was based on data routinely abstracted from hospital records. Elevated risks were identified for certain white collar occupations: for men employed in engineering, the odds ratio (OR) = 2.1; 95% confidence interval (CI) = 0.4, 10.3; for social science professionals, the OR = 6.1; 95% CI = 1.5, 26.1. Among occupations with potential exposure to occupational carcinogens, increased risks were observed for men employed in agricultural crop production (OR = 1.5; 95% CI = 1.0, 2.4), printing and publishing (OR = 2.8; 95% CI = 1.0, 8.3), and brickmasons and tilesetters (OR = 2.5; 95% CI = 0.5, 11.5). Most of elevated brain cancer risks were due to astrocytic cancers, but the excess among agricultural workers occurred in other cell types. No increase in risk was noted for current cigarette smokers (OR = 0.9; 95% CI = 0.7, 1.5) or ex-smokers (OR = 1.0; 95% CI = 0.7, 1.5). This exploratory study indicates a need for further studies of occupational risks of brain cancer.

Astrocytoma↗
PubMed1990

Ultrasonographic diagnosis of fetal cystic hygroma.

Prenatal diagnosis of seven cases of fetal cystic hygroma was characterized by multiloculated cystic mass with septated appearance in relation to the fetal head and neck, as well as various degree of lymphedema and peritoneal effusion and no direct communication with the central nervous system. Karyotype studies were performed in four cases and a composite of karyotypes from literatures is presented. The sonographic appearances and cytogenetic analyses will provide the significant framework needed for accurate prenatal diagnosis and genetic counseling.

Adult↗
PubMed1990

Racial differences in cancer mortality in Missouri.

The discrepancy between black and white cancer mortality rates remains a cause of concern for the public health community. The authors discuss some of the factors that contribute to the problem and suggest that an organized local, state and national effort is necessary to find a solution.

Adult↗
PubMed1989

Cancer risks among Missouri farmers.

A series of case-control studies was conducted to investigate cancer risks among farmers. These studies were based on Missouri Cancer Registry data for 15,000 white male patients, including 1720 subjects classified as farmers, registered between 1984 and 1988. For each cancer site, all other cancer registrations formed the control group. The largest risks among farmers were found for lip cancer (odds ratio [OR], 3.07; 95% confidence interval [CI], 1.99 to 4.73) and cancer of the bone (OR, 2.02; 95% CI, 0.66 to 5.81). Elevated risks were observed for several other sites, including the nasal cavity and sinuses (OR, 1.66; 95% CI, 0.54 to 4.70), prostate (OR, 1.33; 95% CI, 1.18 to 1.51), non-Hodgkin's lymphoma (OR, 1.40; 95% CI, 1.04 to 1.85), and multiple myeloma (OR, 1.40; 95% CI, 0.87 to 2.24). Other smaller elevations in risk were noticed for cancer of the rectum (OR, 1.21; 95% CI, 0.95 to 1.53), liver (OR, 1.19; 95% CI, 0.58 to 2.37), malignant melanoma (OR, 1.26; 95% CI, 0.63 to 2.45), kidney (OR, 1.21; 95% CI, 0.89 to 1.65), and leukemia (OR, 1.12; 95% CI, 0.81 to 1.55); however, some of these estimates were imprecise due to small numbers. The overall OR for lymphatic and hematopoietic cancers was 1.28 (95% CI, 1.06 to 1.56). Consistent with previous studies, a decreased risk of lung cancer was observed among farmers (OR, 0.67; 95% CI, 0.60 to 0.76). The current findings are presented in the context of other recent studies, including discussions of possible causes of farming-associated excess cancer risk and possible sources of bias.

Adult↗
PubMed1989

Study of lung cancer histologic types, occupation, and smoking in Missouri.

A case-control study of lung cancer was conducted to evaluate the relationship between lung cancer histologic types and occupation, adjusted for smoking. A total of 4,431 white male cases and 11,326 cancer controls, diagnosed between 1980 and 1985, were identified through the Missouri Cancer Registry. For all histologic types combined, excess risk was observed among many a priori suspected high-risk occupations. Lung cancer was elevated among men employed as insulators (odds ratio [OR] = 6.0; 95% confidence interval [CI] = 0.7, 137.8), carpenters (OR = 1.3; 95% CI = 1.0, 1.7), painters, plasterers, and wallpaper hangers (OR = 2.0; 95% CI = 1.2,3.3), structural metal workers (OR = 1.9; 95% CI = 0.6,6.0), mechanics and repairers (OR = 1.3; 95% CI = 1.0,1.7), motor vehicle drivers (OR = 1.5; 95% CI = 1.2,1.8), police and firefighters (OR = 1.6; 95% CI = 1.1,2.3), and food service personnel (OR = 1.8; 95% CI = 1.0,3.5). A deficit of lung cancer was observed among farmers (OR = 0.9; 95% CI = 0.7,1.0). Adenocarcinoma of the lung was elevated among carpenters (OR = 1.6; 95% CI = 1.0,2.5) and cabinet and furniture makers (OR = 2.0; 95% CI = 0.4,8.1), which is interesting because of the previous reports of excess adenocarcinoma of the nasal cavity associated with wood dust exposure. Adenocarcinomas were also elevated among plumbers (OR = 2.0; 95% CI = 1.0,3.8) and printers (OR = 1.8; 95% CI = 0.7,4.2). Electricians were at slightly increased risk for adenocarcinoma (OR = 1.5; 95% CI = 0.7,2.8) and "other" or mixed cell types of lung cancer (OR = 1.5; 95% CI = 0.8,2.9) but at decreased risk for small cell (OR = 0.8; 95% CI = 0.3,2.0) and squamous cell (OR = 0.8; 95% CI = 0.4,1.6) tumors. Among welders, adenocarcinoma (OR = 1.7; 95% CI = 0.7,3.8) and squamous cell (OR = 1.7; 95% CI = 0.9,3.3) cancers were elevated, but small cell and "other" lung cancers were not. Despite the limitations of the Cancer Registry data, some interesting associations were observed that merit further study, particularly the association between lung adenocarcinoma and occupational exposure to wood and wood dust.

Adenocarcinoma↗
PubMed1989

Cathepsin B and D activity in alveolar macrophages from rats with pulmonary granulomatous inflammation or acute lung injury.

Cathepsin B and D activity was determined using specific synthetic substrates in alveolar macrophages (AMs) obtained from Sprague-Dawley rats with experimentally induced pulmonary granulomatous inflammation. Increased cathepsin B activity was found 4 days after intravenous injection of complete Freund's adjuvant (CFA), but not after injection of live bacillus Calmette-Guérin organisms (BCG), indicating that the enzyme response was unrelated to the subsequent development of granulomatous inflammation. Findings of comparable increases in enzyme activity following injection of mineral oil (MO) indicate that the response to CFA was due to the oil component. Significantly, oleic acid (OA), a natural fatty acid, did not stimulate enzyme activity although the agent, like MO, caused acute lung injury as assessed by 125I albumin uptake. At 7 and 28 days following injection of CFA, cathepsin B levels in AMs were the same as those in animals given normal saline (NS), although bronchoalveolar lavage (BAL) samples still contained increased numbers of AMs, and cells obtained at 28 days phagocytosed more polystyrene microspheres. Cathepsin D activity did not increase 4 days after injection of CFA or BCG + CFA; at 28 days following injection of BCG + CFA activity was significantly decreased as compared to animals given NS. The data reveal a differential response of two lysosomal enzymes during the early phases of granulomatous inflammation.

Albumins↗
PubMed1989

Human beta-globin gene expression in transgenic mice is enhanced by a distant DNase I hypersensitive site.

Several lines of evidence suggest that erythroid-specific DNase I hypersensitive sites (HS) located far upstream of the human beta-globin gene are important in regulating beta-globin gene expression. We used the polymerase chain reaction technique to amplify and clone an 882-base-pair DNA fragment spanning one of these HS, designated HSII, which is located 54 kilobases upstream of the beta-globin gene. The cloned HSII fragment was linked to a human beta-globin gene in either the genomic (HSII-beta) or antigenomic (HSII-beta) orientation. These two constructs and a beta-globin gene alone (beta) were injected into fertilized mouse eggs, and expression was analyzed in liver and brain from day-16 transgenic fetuses. Five of 7 beta-transgenic fetuses expressed human beta-globin mRNA, but the level of expression per gene copy was low, ranging from 0.93 to 22.4% of mouse alpha-globin mRNA (average 9.9%). In contrast, 11 of 12 HSII-beta transgenic fetuses expressed beta-globin mRNA at levels per gene copy ranging from 31.3 to 336.6% of mouse alpha-globin mRNA (average 139.5%). Only three fetuses containing intact copies of the HSII-beta construct were produced. Two of three expressed human beta-globin mRNA at levels per gene copy of 179.2 and 387.1%. Expression of human beta-globin mRNA was tissue-specific in all three types of transgenic fetuses. These studies demonstrate that a small DNA fragment containing a single erythroid-specific HS can stimulate high-level human beta-globin gene expression in transgenic mice.

Animals↗
PubMed1989

Cigarette smoking and alcohol consumption in the aetiology of uterine cervical cancer.

A case-control study of uterine cervical cancer was conducted using 331 cases and 993 age-matched controls identified through the Missouri Cancer Registry during 1984-1986. Patients with smoking- or alcohol-related cancers were excluded from the control series. Logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (Cls) after adjustment for age, cigarette smoking, alcohol consumption, and stage at diagnosis. A dose-response relation was observed between intensity of cigarette smoking and invasive cervical cancer, with light and heavy smokers having elevated risks (OR = 2.2, 95% Cl = 1.4-3.6 and OR = 3.9, 95% Cl = 2.7-5.6, respectively). Former smokers had less elevated risk (OR = 1.7, 95% Cl = 1.0-2.9), a finding consistent with a greater effect of tobacco smoke on late-stage carcinogenesis. Similar results were obtained in age- and control site-specific analyses. Further, the age-specific data suggested a dose-response relation between duration of smoking and invasive cervical cancer. An association between alcohol consumption and invasive cervical cancer was not observed.

Adolescent↗
PubMed1989

A study of the accuracy of cancer risk factor information reported to a central registry compared with that obtained by interview.

Sources of readily available data for cancer surveillance are frequently sought. To assess the validity of information on cancer risk factors that is routinely collected in conjunction with cancer incidence reporting, the authors completed interviews for 441 patients identified through the Missouri Cancer Registry from June 1986 to May 1987. Interviews elicited information on employment history, smoking, and alcohol consumption. Data collected from interviews were compared with those previously reported to the Registry by participating hospitals. Exact agreements of three-digit US Census codes were 70% for occupation and 72% for industry. Concordance for never- versus ever-smoking status was 83%, and a high correlation (r = 0.93) was observed for level of smoking. Agreement on alcohol consumption was lower (65%), largely because of the presence of false negatives. Misclassification occurred in a random manner for occupational variables; however, differential misclassification was present for smoking and alcohol histories. Despite the limitations of registry-collected data, these findings suggest that cancer registries that obtain information on cancer risk factors may be suitable for exploratory studies, especially those involving occupational cancer surveillance.

Adult↗
PubMed1989

Occupational risk of colon cancer. An analysis by anatomic subsite.

A case-control study was conducted to investigate occupational risks for colon cancer. The Missouri Cancer Registry was used to identify a total of 1,993 white male cases and 9,965 age-matched cancer controls diagnosed between 1984 and 1987. Effect estimates were calculated for specific occupations and industries and for three levels of occupational physical activity. Odds ratios (ORs) and 95% confidence intervals (Cls) were also calculated according to anatomic subsite of colon cancer. Elevated risks were identified for workers in several occupations and industries including printing machine operators (OR = 1.9, 95% Cl 1.0-3.3), workers in food manufacturing (OR = 1.6, 95% Cl 1.2-2.2), communications workers (OR = 1.8, 95% Cl 1.0-3.3), and workers employed in the petroleum product trade (OR = 2.7, 95% Cl 1.0-7.2). Previous findings of excess risk among selected occupations of higher socioeconomic status were confirmed. Analyses by anatomic subsite showed that excess risk for an occupational group was usually confined to a single subsite, which suggests some specificity of effect. For example, elevated risk among males employed in manufacturing-related industries was shown primarily for cancer of the cecum. The findings by level of occupational physical activity corroborated recent reports of increased colon cancer risk associated with employment in sedentary occupations. Excess risk (OR = 1.4, 95% Cl 1.0-1.9) was shown among males employed in sedentary jobs and an inverse linear trend in risk was shown according to level of occupational physical activity. Risk associated with sedentary occupations was highest for cancer of the cecum (OR = 2.1, 95% Cl 1.1-4.0). Despite the limitations of the cancer registry-collected data, some associations were observed that deserve further study.

Adult↗
PubMed1989

Cathepsin D activity is increased in alveolar macrophages and bronchoalveolar lavage fluid of smokers.

Cathepsin D activity was determined in alveolar macrophages (AM) and cell-free bronchoalveolar lavage fluid (BALF) from volunteers who were current cigarette smokers and compared with that found in lifetime nonsmokers. Enzyme activity was determined with a highly sensitive and specific substrate [D-Phe-Ser(0-CH2-C6H5)-Phe-Phe-Ala-Ala-pAB]. Specific activity was more than three times higher in AM from smokers than in cells from nonsmokers (37,880 +/- 2,090 versus 10,300 +/- 1,200; p less than 0.001) and approximately seven times higher in BALF from smokers than from nonsmokers (3,620 +/- 490 versus 515 +/- 165; p less than 0.001). This study demonstrated that cigarette smoke is a potent inducer of cathepsin D activity in AM in vivo. Because cathepsin D is capable of degrading a variety of proteins, the finding of high concentrations of the enzyme in AM and BALF from smokers, along with previous observations of elevated cathepsin B activity, suggests that lysosomal enzymes may cause or contribute to structural lung damage associated with cigarette smoking.

Adult↗
PubMed1989

Ligamentotaxis and bone grafting for comminuted fractures of the distal radius.

The conventional treatment of comminuted fractures in the distal radius has been unsatisfactory. We therefore made a prospective study using the principle of ligamentotoxis and primary cancellous bone grafting as the uniform method of treatment. Ligamentotaxis was maintained by using an external fixator for three weeks only, after which a carefully monitored programme of rehabilitation was given. We have reviewed 72 consecutive distal radial fractures after a follow-up of 7 to 40 months (average 11 months). Reduction had been maintained during healing and over 80% of patients regained full range of movement in hands, wrists and forearms with strong and pain-free wrist function. Complications were infrequent and gave no real problems. We conclude that distraction, external fixation and bone grafting appears to be an excellent method of treating comminuted fractures of the distal radius.

Adolescent↗