The determinants of physician and pharmacist utilization and equity of access under Korean universal health insurance

This study examines the social and behavioral determinants of two types of primary care, seeing a physician or a pharmacist, for Koreans and evaluates the equity of the Korean national health insurance system. The study applies the Aday and Andersen access framework to cross-sectional data from the 1992 Korean National Health Interview Survey (N = 21,841).^ The study found that in Korea, the elderly were most likely, and children least likely, to have used physician services. Women, household heads, those in small families, and the less educated were more likely than their counterparts to use physician and pharmacist services. Health status and need were important determinants of Koreans seeing a doctor or a pharmacist. Differences in need substantially accounted for the original differences observed between subgroups. Resources associated with having insurance coverage, a regular source of care, and place of residence (rural/urban) ameliorated to some extent the subgroup differences in the use of physicians' and pharmacists' services among Koreans. They were also major independent predictors of access. Having insurance remains a particularly important predictor of who uses physician services. Among the insured, trade-offs in the use of physician and pharmacist services were found in the current system, i.e., uninsured and poor Koreans were more likely to use pharmacist services, while insured and rural Koreans were more likely to use doctor services. Among the insured, cost sharing rates are lower for physician than for pharmacist services. Self-employed persons were less likely than government and industrial workers to use physician services. An underlying expectation under universal health insurance was that the Korean health care system would be equitable. The research results, however, did not fully support this expectation.^ The policy implications of these findings are that measures are required to extend insurance coverage to the uninsured, to equalize differences in benefit packages between health plans, and to expand the availability of physicians in rural areas. Further research is also needed to understand those who do not currently have a regular source of care and why and the access barriers that may exist for selected demographic subgroups (those in large families and unmarried or divorced/widowed persons). ^

THE EFFECT OF RELAXIN ON BIOCHEMICAL AND MORPHOLOGICAL PARAMETERS OF RAT MYOMETRIAL CELLS IN CULTURE (CYCLIC-AMP, CELL SHAPE CHANGE)

Relaxin is able to inhibit spontaneous, oxytocin-and prostaglandin-driven uterine contractions. The intracellular mechanism of action of relaxin on uterine relaxation had previously been studied using isometrically suspended uterine strips. Since uterine strips contain stroma as well as myometrium, the changes in biochemical parameters induced by relaxin treatment may not occur in the same cell types responsible for the physical changes. In these studies, cultures of enriched populations of rat myometrial cells were used to investigate the effect of relaxin on biochemical and morphological parameters which are related to relaxation.^ Under optimal culture conditions (initial plating density 1 - 1.5 x 10('6)cells/ml, 3 ml/35 mm dish, 2 days culture), enzymatically isolated rat myometrial cells were able to respond to relaxin with cAMP elevation. Relaxin elevated cAMP levels in the presence but not the absence of 0.1 mM methylisobutylxanthine or 0.4 um forskolin in a time- and concentration-dependent manner. In contrast, isoproterenol was able to elevate cAMP levels in the presence and absence of 0.1 mM methylisobutylxanthine.^ Oxytocin treatment caused a decrease in mean cell length and area of myometrial cells in culture which could be considered analogous to contraction. Under optimal culture conditions, relaxin increased myometrial cell length and area (i.e. analogous to relaxation) of oxytocin-treated cells in a time- and concentration-dependent manner. Other relaxants such as isoproterenol and dibutyryl cAMP also increased cell length and area of oxytocin - treated myometrial cells in culture.^ Under optimal culture conditions, relaxin decreased myosin light chain kinase activity in a time-and concentration-dependent manner by increasing the K(,50) of the enzyme for calmodulin (CaM), i.e. decreasing the affinity of the enzyme for CaM. The decrease in the affinity of myosin light chain kinase for CaM may be due to the phosphorylation of the enzyme by cAMP-dependent protein kinase. Relaxin also decreased the Ca('2+)(.)CaM-independent myosin light chain kinase activity to a lesser extent than that of the Ca('2+)(.)CaM-dependent enzyme activity. This was not attributable to a decrease in the affinity of the enzyme for myosin in myometrial cells in culture, in contrast to the finding of such a change following relaxin treatment of uterine strips. Further studies are required to clarify this point.^ There was a temporal association between the effects of relaxin on elevation of cAMP levels in the presence of 0.4 uM forskolin, increase in cell length and decrease in myosin light chain kinase activity. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI ^

The role and mechanism of supressor of cytokine signaling 1 in brain metastasis

Brain metastasis, which occurs in 40%-60% of patients with advanced melanoma, has led directly to death in the majority of cases. Unfortunately, little is known about the biological and molecular basis of melanoma brain metastases. In our previous study, we developed a model to study human melanoma brain metastasis and found that Stat3 activity was increased in human brain metastatic melanoma cells when compared with that in cutaneous melanoma cells. The increased activation of Stat3 is also responsible for affecting melanoma angiogenesis in vivo and melanoma cell invasion in vitro and significantly affecting the expression of bFGF, VEGF, and MMP-2 in vivo and in vitro. Interestingly, a member of a new family of cytokine-inducible inhibitors of signal transduction, termed suppressors of cytokine signaling 1 (SOCS1) was found to negatively regulate the Janus kinase signal transducer and activator of transcription (Jak/STAT) signaling cascade. Here we report that restoration of SOCS1 expression by transfecting of SOCS1-expressing vector effectively inhibited melanoma brain metastasis through inhibiting Stat3 activation and further affecting melanoma angiogenesis and melanoma cell invasion in vitro, and significantly affected the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in vitro and in vivo. In addition, we used cDNA array to compare mRNA expression in the SOCS1-transfected and vector-transfected cell lines and found some genes are tightly correlated to the restoration of SOCS1. One of them is Caveolin-1 (Cav-1). Cav-1 was reported to function as a tumor suppressor gene by several groups. Finally, the Cav-1 expression is up-regulated in SOCS1-overexpressing cell line. Further study found the regulation of Cav-1 by SOCS1 occurs through inhibiting Stat3 activation. Activated Stat3 binds directly to Cav-1 promoter and the Cav-1 promoter within -575bp is essential for active Stat3 binding. My studies reveal that Stat3 activation and SOCS1 expression play important roles in melanoma metastases. Moreover, the expression between SOCS1, Stat3 and Cav-1 forms a feedback regulation loop. ^

Prognosis of amyotrophic lateral sclerosis

Two cohorts of amyotrophic lateral sclerosis (ALS) patients were identified. One incidence-based cohort from Harris County, Texas with 97 cases, and the other a clinic referral series from an ALS clinic in Houston, Texas with 439 cases were followed-up to evaluate the prognosis of ALS. The overall Kaplan-Meier 3-year survival after diagnosis was similar, 0.287 for the incidence cohort and 0.313 for the referral cohort. However, the 5-year survival was much lower for the incidence cohort than the referral cohort (0.037 vs. 0.206). The large difference in 5-year survival was thought to be the results of a stronger unfavorable effect of the prognostic factors in the incidence cohort than in the referral cohort.^ Cohort-specific Weibull regression models were derived to evaluate the cohort-specific prognostic factors and survival probability with adjustment of certain prognostic factors.^ The major prognostic factors were: age at diagnosis, bulbar onset, black ethnicity, and positive family history of ALS in both cohorts. Female gender, simultaneous upper and lower extremities onset were specifically unfavorable factors in the incidence cohort. In the incidence cohort the prognosis was relatively favorable for cases with duration from onset to diagnosis longer than 4 months, however in the referral cohort the relatively favorable prognosis only occurred in cases with duration from onset to diagnosis 1 year or longer and was strongest in cases with duration 5 years and longer. Age at diagnosis modified the effect of bulbar onset in the incidence cohort but not in the referral cohort. The estimated survival with presence of an unfavorable prognostic factor identified in the incidence cohort was higher for the referral cohort than for the incidence cohort. Future studies are indicated to investigate the disease heterogeneity issue of ALS based on survival distribution of ALS. ^

DEVELOPMENT AND APPLICATION OF SHORT-TERM MUTAGENICITY AND CYTOTOXICITY BIOASSAYS FOR INTEGRATED HEALTH ASSESSMENT STUDIES OF COAL FLY ASH EMISSIONS

Two respirable coal fly ash samples ((LESSTHEQ) 3(mu)m), one from a pressurized fluidized-bed combustion miniplant and one from a conventional combustion power plant, were investigated for physical properties, chemical composition and biological activity. Electron microscopy illustrated irregularity in fluidized-bed combustion fly ash and sphericity in conventional combustion fly ash. Elemental analysis of these samples showed differences in trace elements. Both fly ash samples were toxic in rabbit alveolar macrophage and Chinese hamster ovary cell systems in vitro. The macrophages were more sensitive to toxicity of fly ash than the ovary cells. For measuring the cytotoxicity of fly ash, the most sensitive parameters were adenosine triphosphate in the alveolar macrophage system and viability index in the hamster ovary system. Intact fluidized-bed combustion fly-ash particles showed mutagenicity only in strains TA98 and TA1538 without metabolic activation in the Ames Salmonella assay. No mutagenicity was detected in bioassay of conventional combustion fly ash particles. Solvent extraction yielded more mass from fluidized-bed combustion fly ash than from conventional combustion fly ash. The extracts of fluidized-bed combustion fly ash showed higher mutagenic activity than conventional combustion fly ash. These samples contained direct-acting, frameshift mutagens.^ Fly ash samples collected from the same fluidized-bed source by cyclones, a fabric filter, and a electrostatic precipitator at various temperatures were compared for particle size, toxicity, and mutagenicity. Results demonstrated that the biological activity of coal fly ash were affected by the collection site, device, and temperature.^ Coal fly ash vapor-coated with 1-nitropyrene was developed as a model system to study the bioavailability and recovery of nitroaromatic compounds in fly ash. The effects of vapor deposition on toxicity and mutagenicity of fly ash were examined. The nitropyrene coating did not significantly alter the ash's cytotoxicity. Nitropyrene was bioavailable in the biological media, and a significant percentage was not recovered after the coated fly ash was cultured with alveolar macrophages. 1-Nitropyrene loss increased as the number of macrophages was increased, suggesting that the macrophages are capable of metabolizing or binding 1-nitropyrene present in coal fly ash. ^