Single domain m-plane ZnO grown on m-plane sapphire by radio frequency magnetron sputtering.

High-quality m-plane orientated ZnO films have been successfully grown on m-plane sapphire by using radio frequency magnetron sputtering deposition. The introduction of a nanometer-thick, low-temperature-grown ZnO buffer layer effectively eliminates inclusions of other undesirable orientations. The structure characteristics of the ZnO epi-layers were thoroughly studied by synchrotron X-ray scattering and transmission electron microscopy (TEM). The in-plane epitaxial relationship between ZnO and sapphire follows (0002)(ZnO) [parallel] (112[overline]0)(sapphire) and (112[overline]0)(ZnO) [parallel] (0006)(sapphire) and the ZnO/sapphire interface structure can be described by the domain matching epitaxy along the [112[overline]0](ZnO) direction. The vibrational properties of the films were investigated by polarization dependent micro-Raman spectroscopy. Both XRD and micro-Raman results reveal that the obtained m-ZnO layers are under an anisotropic biaxial strain but still retains a hexagonal lattice.

Generation of neutrophil-chemoattractant by degradation of tumor cell membrane protein.

Polymorphonuclear leukocytes (PMN) infiltrating into tumors are assumed to be the result of a migration in response to a tumor-derived chemotactic factor. It is hypothesized that tumor-derived chemotactic factors, which are supposed to be in aggregates, can be exposed by proteolytic degradation of the tumor cell membrane protein (TCM). The TCM suspension made from either Sarcoma 180 or Ehrlich ascites tumor after incubation with Varidase at 37 degrees C for six to eight weeks is referred to as a degraded TCM protein (DTCM). The purpose of this study was to detect whether or not the DTCM was chemotactic for PMNs. Chemotactic activity was assayed by a sponge-matrix model and expressed in the number of PMNs infiltrating into the sponge per mouse after intrasponge injection of the DTCM, dose range, 0.4-0.005 mL. Maximal response to DTCM was restricted to the limited dose between 0.01 and 0.02 mL. Quantities of DTCM > 0.02 mL caused a response in roughly reciprocal proportion to the dose of DTCM. Changes in the circulating leukocyte count in response to an intravenous (i.v.) injection of DTCM was biphasic. The initial relative leukopenia was followed by leukocytosis within 24 hours in rats surviving the effect of DTCM doses < 0.5 mL. However, in rats with i.v. injections of higher doses, profound leukopenia was present at death. The mice, after an intraperitoneal (i.p.) injection of DTCM, dose range, 0.5-1.0 mL, died between 16 and 24 hours after the injection. The bone marrow of these mice showed complete depletion of PMNs.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B virus e antigen and primary hepatocellular carcinoma.

Serum samples from 243 cases of primary hepatocellular carcinoma (PHC) and 302 non-PHC hospital controls were tested for hepatitis B virus (HBV) surface antigen (HBsAg), antibody to HBsAg (anti-HBs), antibody to HBV core antigen (anti-HBc), HBV e antigen (HBeAg) and antibody to HBeAg (anti-HBe) with radioimmunoassays using commercial kits. A total of 236 (97%) PHC cases and 302 (100%) hospital controls were positive for one or more HBV markers. While 188 (77%) PHC cases and 57 (19%) controls were positive for HBsAg, 44 (18%) PHC cases and 5 (2%) controls were positive for both BHsAg and HBeAg. Statistically significant associations with PHC were observed for HBsAg and HBeAg with an odds ratio (OR) of 10.0 and 3.2, respectively, when age, sex and other markers were adjusted. The stratification analysis of interactive effects of HBV infection markers on the development of PHC showed that HBeAg carrier status may increase PHC risk associated with HBsAg status.

[MAC-ELISA for the detection of IgM antibodies to dengue type I virus (rapid diagnosis of dengue type I virus infection)].

The commercial rapid diagnostic reagents for Dengue virus infection is still not available at present. An ABC MAC-ELISA (Avidin Biotin Complex IgM Antibody Capture Enzyme Linked Immunosorbent Assay) for the detection of Dengue type I virus infection has been described. IgG purified from high titer (HI = 2560) human anti-flavivirus serum is labelled with biotin for the rapid diagnosis of Dengue type I virus infection. 389 serum specimens of suspected Dengue Fever patients including 226 HI(+) paired sera and 163 HI(-) paired sera which were collected from 1 to 150 days after onset of the disease in 1988 have been assayed for IgM antibodies to Dengue type I virus. Cut off value is based on the mean of OD490 of 162 Dengue negative serum specimens plus 4 SD. The positivity of IgM antibody increased as the viremia disappeared and IgM antibody for Dengue-1 serum specimens collected 9 days after onset of the disease is 100% detectable.

Hepatitis B virus markers in Chinese twins.

Chinese same-sex twins were recruited in order to study the distribution of different markers of hepatitis B virus (HBV) infection, including HBV surface antigen (HBsAg), antibody to HBV core antigen (anti-HBc), antibody to HBsAg (anti-HBs), HBV e antigen (HBeAg) and antibody to HBeAg (Anti-HBe), as well as to compare the concordance of these markers in pair-wise fashion among monozygotic (MZ) and dizygotic (DZ) twins and singleton controls. A total of 289 pairs of MZ twins, 102 pairs of DZ twins and 375 pairs of age-sex-matched singleton controls were studied. More than 50 percent of the members of each group (64.71% of MZ twins, 51.96% of DZ twins and 62.13% of controls) were found to be infected with HBV. In general, the patterns of the response to HBV infection in the 3 groups were similarly distributed. 20.17% of the members of the 3 groups (21.45% of MZ twins, 14.22% of DZ twins, and 20.80% of controls) were HBsAg carriers. Among the HBsAg carriers, 49.19% (44.35% of MZ twins, 34.48% of DZ twins and 55.77% of controls) were HBeAg carriers. No significant difference in the concordance of HBV infection was observed in the MZ and DZ twins. However, highly significant differences were noted between MZ twins and controls, and between DZ twins and controls. Highly significant differences were also observed in the concordance of carrier status between MZ and DZ twins and between MZ twins and controls, but not between DZ and controls. As for the other HBV markers, no significant differences were observed. It is concluded that the genetic influence in response to HBV infection markers is not well-characterized and requires further study.

A case-control study of primary hepatocellular carcinoma in Taiwan.

A case-control study was carried out to explore possible risk factors of primary hepatocellular carcinoma (PHC) in Taiwan. One hundred thirty-one PHC patients and 207 hospital control patients were interviewed and blood samples were collected for blood type and hepatitis B virus (HBV) infection marker tests. Eighty-three percent of the PHC patients were found to be hepatitis B surface antigen (HBsAg) positive as compared with 21.0% of the control patients with an odds ratio (OR) of 21.5. Hepatitis B e antigen (HBeAg) positive status increased the risk of PHC. No significant association was observed between erythrocyte genetic markers and PHC, except c of the Rh system, which was significantly lower in the PHC cases. As compared with the control patients, the PHC patients had a higher proportion with a history of liver diseases and more siblings affected with liver diseases. However, the variables such as cigarette smoking, alcohol drinking, peanut consumption, frequent intake of raw fish, heart diseases, peptic ulcer, malaria, hypertension, diabetes, color blindness, G-6-PD deficiency, surgical operation, blood transfusion, and liver diseases of parents and children were not found to be associated with PHC.

Serological survey of immune response to tetanus toxoid using antitoxin enzyme immunoassay.

A method for testing serum tetanus immunoglobulin (TIG) was set up using enzyme immunoassay kit (EIA kit) and prepared by competitive principle in this laboratory. Forty-eight human sera tested by both EIA and toxin neutralization test (NT) in mice were in good agreement. Determination coefficient (r2) of the EIA and NT was 0.922. The lowest detectable dose was 0.1 IU/mL ELISA value. Many authors believe this ELISA value to be a safe protection TIG level. For serological survey of immune response to tetanus toxoid, sera from two groups of subjects were examined. Among 83 subjects, each over 40 years of age, only 47.0% were positive to TIG EIA level. Forty-six subjects with undetectable EIA titres to tetanus toxoid (TT) were immunized against two doses of TT at an interval of four weeks; 44 (95.6%) demonstrated TIG concentration of greater than or equal to 0.2 IU/mL within two weeks to one month following the last dose vaccination. The TIG positive rates of 725 school students' sera, selected by multistage sampling from 2395 specimens, were reported. Those were collected by simple random sampling from geographical area in the North, South, Central, Central Mountain, and East areas of Taiwan according to age groups. They were 80.8%, 65.1%, 56.0%, and 42.0% to the age groups of 0-4, 5-9, 10-14, and 15-17 years respectively. The probabilities of each near by two groups were p less than 0.1; p less than 0.05; p less than 0.05. The differences of positive rates in the last three groups were significant.

Potent induction of human placental mono-oxygenase activity by previous dietary exposure to polychlorinated biphenyls and their thermal degradation products.

Placental tissues were obtained from women in Taiwan who had ingested rice oil contaminated with aromatic polychlorinated hydrocarbons 3-4 years before conception. Known contaminants in the rice oil were polychlorinated biphenyls and their thermal degradation products, including polychlorinated dibenzofurans and polychlorinated quaterphenyls. Placental homogenates showed large increases in mono-oxygenase enzymes, including aryl hydrocarbon hydroxylase, 7-ethoxycoumarin O-de-ethylase, and diol, quinone, and phenolic metabolites of benzo(a)pyrene (analysed by high performance liquid chromatography). The findings suggest that exposure to these widespread, environmental pollutants may exert substantial and persistent metabolic effects.

Discovery and epidemiology of PCB poisoning in Taiwan: a four-year followup.

An outbreak of polychlorinated biphenyl (PCB) poisoning from the consumption of contaminated rice oil, covering four counties in central Taiwan, was investigated. There were 1843 cases by the end of 1980. The highest frequency of incidence occurred during the period from March to July 1979. The severity of clinical manifestations varied. Most patients showed symptoms of mild or moderate severity. The major age group affected was between 11 and 20 years old. Most of the victims were students and factory workers. The amount of PCB intake in each victim was estimated to be 0.7 to 1.84 g and the latent period from the time of intake to the onset of clinical manifestations was approximately 3 to 4 months. The patients' blood PCB concentrations ranged from 3 ppb to 1156 ppb; 44.27% of 613 patients had levels of 51 to 100 ppb and 27.6% PCB blood levels over 100 ppb. In the course of 3.5 years, 2061 persons were determined to be PCB poisoning victims. Now, except for a few severe cases, their skin symptoms are very much improved. Thirty-nine babies showing hyperpigmentation were born from PCB-poisoned mothers. The fatality rate was high: eight of them died. Another 24 deaths were reported among the PCB-poisoned group, almost half of them (12) from hepatoma, liver cirrhosis or liver diseases with hepatomegaly.