Uptake of arsenic species by turnip (Brassica rapa L.) and lettuce (Lactuca sativa L.) treated with roxarsone and its metabolites in chicken manure

Roxarsone is an organoarsenic feed additive that can be metabolised to other higher toxic arsenic (As) species in animal manure such as arsenate, arsenite, monomethylarsonic acid, dimethylarsinic acid, 3-amino-4-hydroxyphenylarsonic acid and other unknown As species. The accumulation, transport and distribution of As species in turnip (Brassica rapa L.) and lettuce (Lactuca sativa L.) amended with roxarsone and its metabolites in chicken manure were investigated. Results showed arsenite was the predominant As form, followed by arsenate in turnip and lettuce plants, and a low content of dimethylarsinic acid was detected only in lettuce roots. Compared with the control plants treated with chicken manure without roxarsone and its metabolites, the treatments containing roxarsone and its metabolites increased arsenite content by 2.0-3.2% in turnip shoots, by 6.6-6.7% in lettuce shoots, by 11-44% in turnip tubers and by 18-20% in lettuce roots at two growth stages. The enhanced proportion of arsenate content in turnip shoots, turnip tubers and lettuce roots was 4.3-14%, 20-35% and 70%, respectively, while dimethylarsinic acid content in lettuce roots increased 2.4 times. Results showed that the occurrence of dimethylarsinic acid in lettuce roots might be converted from the inorganic As species and the uptake of both inorganic and organic As compounds in turnip and lettuce plants would be enhanced by roxarsone and its metabolites in chicken manure. The pathway of roxarsone metabolites introduced into the human body via roxarsone → animal → manure → soil → crop was indicated.

In situ oxidation of petroleum-hydrocarbon contaminated groundwater using passive ISCO system

Groundwater contamination by gasoline spill is a worldwide environmental problem. Gasoline contains methyl tertiary-butyl ether (MTBE) (a fuel oxygenates) and benzene, which are the chemicals of concerns among the gasoline components. In this study, an in situ chemical oxidation (ISCO) barrier system was developed to evaluate the feasibility of applying this passive system on the control of MTBE and benzene plume in aquifer. The developed ISCO barrier contained oxidant-releasing materials, which could release oxidants (e.g., persulfate) when contact with water for the contaminants' oxidation in groundwater. In this study, laboratory-scale fill-and-draw experiments were conducted to determine the component ratios of the oxidant-releasing materials and evaluate the persulfate release rates. Results indicate that the average persulfate-releasing rate of 7.26 mg S(2)O(8)(2-)/d/g was obtained when the mass ratio of sodium persulfate/cement/sand/water was 1/1.4/0.24/0.7. The column study was conducted to evaluate the efficiency of in situ application of the developed ISCO barrier system on MTBE and benzene oxidation. Results from the column study indicate that approximately 86-92% of MTBE and 95-99% of benzene could be removed during the early persulfate-releasing stage (before 48 pore volumes of groundwater pumping). The removal efficiencies for MTBE and benzene dropped to approximately 40-56% and 85-93%, respectively, during the latter part of the releasing period due to the decreased persulfate-releasing rate. Results reveal that acetone, byproduct of MTBE, was observed and then further oxidized completely. Results suggest that the addition of ferrous ion would activate the persulfate oxidation. However, excess ferrous ion would compete with organic contaminants for persulfate, and thus, cause the decrease in contaminant oxidation rates. The proposed treatment scheme would be expected to provide a more cost-effective alternative to remediate MTBE, benzene, and other petroleum-hydrocarbon contaminated aquifers. Results from this study will be useful in designing a scale-up system for field application.

Effects of sphingosine-1-phosphate and lysophosphatidic acid on human osteoblastic cells

The effects of the lysophospholipids, sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) were studied in human primary osteoblastic cells and the human osteosarcomal cell lines, G292 and MG-63. The studies focused on the role of the Gi protein in the regulation of S1P and LPA-induced proliferation, the effects of the phospholipids on alkaline phosphatase, an early marker of osteoblastic cell proliferation, and the presence of edg receptors. Proliferation was assessed by 3H-thymidine incorporation. Short-term incubation with S1P or LPA induced increases in proliferation that were attenuated in the presence of the Gi inhibitor, pertussis toxin. Alkaline phosphatase activity was measured with a spectrophotometric assay. Biphasic effects of S1P and LPA were observed with the nature of the response dependent upon the cell type, concentration of test agent and the time period of incubation. RTPCR studies revealed that edg-1,2,4,5 receptors are present in the primary normal osteoblastic cells, the MG63 and G292 cells. Only the G292 cells expressed the edg-3 receptor to any significant extent.

Mutations of the cationic trypsinogen gene in hereditary and non-hereditary pancreatitis

BACKGROUND/AIMS

Mutations in the cationic trypsinogen gene have been detected in patients with hereditary pancreatitis (HP). This study investigates the prevalence of the R122H, N29I, A16V and -28delTCC mutations in the common, non-hereditary forms of chronic pancreatitis and in a HP family.

METHODS

DNA was prepared from blood samples of 53 patients with chronic pancreatitis (36 alcoholic, 14 idiopathic and 3 hereditary), 20 alcoholic controls and 20 healthy, ethnically matched controls. The R122H and A16V mutations were identified by the polymerase chain reaction (PCR) and restriction enzyme digestion. A nested-PCR was used to identify the N29I mutation. The -28delTCC deletion and the C133807T polymorphism were sought by direct sequencing.

RESULTS

The R122H mutation was detected in 1 patient with alcoholic chronic pancreatitis and all 3 affected members of a HP family. The N29I, A16V and -28delTCC mutations were not detected in any of the study subjects. At the C133807T polymorphism, the C allele and C/C genotype were significantly increased in alcoholic chronic pancreatitis (p = 0.001 and p = 0.0004, respectively) while the T allele and CT genotype were significantly reduced (p = 0.001 and p = 0.004, respectively) compared to healthy controls.

CONCLUSIONS

Mutations of the cationic trypsinogen gene are rarely found in chronic pancreatitis patients of typical aetiology. Screening for these mutations should be considered in those with a family history consistent with hereditary pancreatitis but may also be appropriate in a well-defined subgroup of patients with non-hereditary chronic pancreatitis, i.e. those who have developed the disease before the age of 30.

The impact of economic crisis on health-care consumption in Korea

This study uses urban household income-expenditure survey data, national health insurance claims data, and public health centre surveys to examine the impact of economic crisis on the consumption of health services in Korea. The analysis shows that the health-care consumption of Korean households has been adversely affected by the recent economic crisis, as measured by amount of expenditure on health. Distributional implications for health sector use are also found. Whereas the use of medical services by upper income groups is only slightly affected by the economic crisis, lower income groups are spending relatively less on medical services. Of all households, unemployed households are hit hardest by the crisis. Analysis shows that for all households, the rate of expenditure decrease is relatively higher for drug expenditure than for expenditure on medical services. That is, facing declining income, people cut their spending in the area where the need is non-essential or less inevitable.

NFkappaB polymorphisms and susceptibility to type 1 diabetes

Nuclear factor kappa B (NFkappaB) is an important transcription factor that is involved in the response to oxidative stress and inflammation. Recent studies suggest that it may be involved in the development of diabetic microvascular complications. A highly polymorphic (CA) dinucleotide repeat microsatellite has been identified in the regulatory region of the NFkappaB gene. The aim of this study was to investigate whether this polymorphic region was associated with susceptibility to type 1 diabetes, or its late complications. Genomic DNA was extracted from the peripheral blood of 217 patients with type 1 diabetes mellitus (T1DM) and 111 normal healthy controls. In our population 18 alleles (A1-A18) were identified. There was a highly significant decrease in the frequency of allele 146 bp (A14) in type 1 diabetes (0.03) compared with the normal controls (0.28) (chi(2) = 79.8, Pc = 0.00001). In contrast, the frequency of the allele 138 bp (A10) was significantly increased in patients with type 1 diabetes (0.17) compared with the normal controls (0.02) (chi(2) = 32.8, P < 0.00000). These results demonstrate that the NFkappaB gene may play a role in the susceptibility to type 1 diabetes: individuals with the A10 allele may be more likely to develop diabetes compared with the A14 allele.

Economic evaluation of the societal costs of hepatitis B in South Korea

BACKGROUND AND AIMS

Hepatitis B (HBV) infection remains a major public health problem in South Korea, and accounts for considerable morbidity and mortality. At present, very little is known about the cost of HBV to the South Korean health-care system and society. The present study was therefore conducted to estimate the total annual cost of HBV infection in South Korea for a given year (1997).

METHODS

The study was conducted from the South Korean societal perspective, taking into account the direct and indirect costs of HBV vaccination programs (prevention costs), and those related to the treatment of acute and chronic hepatitis, cirrhosis and liver cancer (disease costs). Several assumptions were made in arriving to actual cost estimates.

RESULTS

The total societal cost of HBV in 1997 was 1078.3 billion Won ($US 959.7 million), 142.3 billion Won or 13.2% being attributable to prevention costs and 225.4 billion Won or 20.9% being attributable to indirect costs of HBV-related diseases. The total cost (direct plus indirect) associated with HBV-related diseases to the South Korean society was 936.1 billion Won ($US 833.1 million), of which 45.3% was attributable to cirrhosis-related costs. In terms of disease-related direct costs alone (710.5 billion Won or $US 632.3 million), the estimated annual spending per patient was 1.37 million Won ($US 1219). The direct costs of the HBV disease (prevention and disease treatment, amounting to 782.2 billion Won or $US 696.2 million) is equivalent to 3.2% of the national health-care expenditure for 1997.

CONCLUSIONS

This study confirms that HBV is a significant cost burden to the South Korean society, and in the absence of an effective cure reinforces the importance of continued disease prevention via vaccination.

Chemokines MCP-1 and RANTES in isolated rat pancreatic acinar cells treated with CCK and ethanol in vitro

The role of cholecystokinin (CCK) and ethanol on the expression and secretion of monocyte chemoattractant protein-1 (MCP-1) and regulated on activation, normal T-cell expressed and secreted (RANTES) chemokines from isolated rat pancreatic acinar cells was investigated. CCK at concentrations of 1 nM and 100 nM and ethanol at concentrations of 75, 200, 400, and 600 mM were used to stimulate isolated acini. The levels of MCP-1 and RANTES in the incubation medium were determined by enzyme-linked immunoabsorbent assay (ELISA). In the control groups, MCP-1 and RANTES were secreted into the incubation medium, and both increased with time. MCP-1 increased from baseline 17.6 pg/ml to 74.1 pg/ml, whereas RANTES increased from 255.5 to 318.3 pg/ml at 390 min. CCK at 100 nM caused a sustained increase in MCP-1 levels to 89.6 pg/ml at 390 min in the incubation medium, whereas the levels of RANTES gradually decreased after 180 min and reached its lowest level at 390 min. Ethanol at a concentration of 600 mM increased the levels of RANTES in the incubation medium, but inhibited the levels of MCP-1 at all concentrations (75, 200, 400, and 600 mM). In summary, rat pancreatic acinar cells secrete MCP-1 and RANTES, and the stimulation of these chemokines by CCK and ethanol suggests that they may be involved in the pathogenesis of acute pancreatitis.

Thoracic aorta: rapid black-blood MR imaging with half-Fourier rapid acquisition with relaxation enhancement with or without electrocardiographic triggering

PURPOSE

To evaluate and compare findings for thoracic aortic disease with three black-blood magnetic resonance (MR) pulse sequences: half-Fourier rapid acquisition with relaxation enhancement (RARE), with and without electrocardiographic (ECG) triggering, and ECG-triggered turbo spin echo (SE).

MATERIALS AND METHODS

Axial black-blood MR images of the chest acquired at 1.5 T with a phased-array coil were obtained in 38 consecutive patients referred for evaluation of thoracic aortic disease. ECG-triggered and nontriggered half-Fourier RARE images were compared with T1-weighted ECG-triggered turbo SE images. Two readers independently scored images for each of the following parameters: ghosting artifacts; clarity of the mediastinum, cardiac chambers, and aortic wall; conspicuity of abnormality; intraluminal signal void uniformity; and overall image quality.

RESULTS

Both half-Fourier RARE sequences outperformed the turbo SE sequence for all measured parameters. Scores for the ECG-triggered half-Fourier RARE sequence were significantly (P < .05) higher than those for the nontriggered version for clarity of the mediastinum and aortic wall, conspicuity of any abnormality other than aortic dissection, and overall image quality. Mean acquisition times for the ECG-triggered (48 seconds) and nontriggered (30 seconds) sequences were significantly shorter than that for the turbo SE sequence (2 minutes 20 seconds).

CONCLUSION

Rapid black-blood half-Fourier RARE sequences, with or without ECG triggering, can replace ECG-triggered turbo SE sequences for evaluation of thoracic aortic disease.

MR-guided needle aspiration biopsies of hepatic masses using a closed bore magnet

PURPOSE

Our purpose was to assess the efficacy of MR-guided biopsies with a conventional superconducting MR scanner and describe the techniques used to achieve successful results.

METHOD

Fourteen biopsies were completed under MR guidance in 11 patients. Seven patients with previously detected lesions were referred for biopsy under MR guidance when hepatic lesions were identified by MRI but not with prebiopsy noncontrast CT or ultrasound (US). Additionally referred for MR-guided biopsy were four patients in whom previous CT- or US-guided biopsies of focal lesions were nondiagnostic. A 22 gauge MR-compatible needle was used in each case. Lesions ranged in size from 8 to 32 mm. Eleven lesions (eight patients) were suspected of being hepatomas, and three lesions (three patients) were suspected of being metastases.

RESULTS

Thirteen of 14 MR-guided biopsies (93%) were diagnostic. Hepatocellular carcinoma was confirmed in 6 of 11 lesions suspected of representing hepatoma. One lesion, in a patient treated with chemoembolization, demonstrated necrotic material. One lesion yielded nondiagnostic material despite repeated visualization of the needle tip in the target lesion. Three lesions demonstrated metastatic carcinoma. Benign hepatocytes were detected in three biopsy specimens. Seven of the lesions that were successfully biopsied measured < 2.5 cm in diameter.

CONCLUSION

With use of a closed bore 1.5 T system, diagnostic MR-guided needle aspiration biopsies of hepatic masses and subcomponents, including small lesions (< 2.5 cm), can be successfully obtained.

The role of health insurance in the growth of the private health sector in Korea

The Korean health care system has been recognized by other countries for its rapid expansion of national health insurance. The government's policy of promoting the private sector, relying on market forces for various allocation decisions, and using the fee-for-service payment system has created a number of challenges for the Korean health system. Among these are rapid growth of health care expenditure, proliferation and duplication of medical technology, and lack of access for low-income groups due to high out-of-pocket payments for services covered by insurance. A number of recommendations are made concerning national health policy, modifying health insurance, and developing political consensus for bringing about health reform.

Analysis of immunoglobulin G subclass in the serum antibody responses of alveolar echinococcosis patients after surgical treatment and chemotherapy as an aid to assessing the outcome

Immunoglobulin G (IgG) subclass-specific antibody responses were evaluated for the follow-up of alveolar echinococcosis (AE) patients. Seventy-four sequentially collected sera from 25 Chinese and French AE cases who underwent surgery including hepatectomy, liver transplant and/or chemotherapy were analysed quantitatively and qualitatively during the clinical follow-up period. These AE patients were classified in 4 groups--cured, improved, stabilized, or aggravated. Serum antibody levels of the subclasses IgG1 and IgG4 were significantly higher in the AE patients than in healthy controls. IgG1 and IgG4 isotypes in AE patients were the most sensitive IgG antibody response in an enzyme-linked immunosorbent assay (ELISA) and in binding to antigens of 44kDa, 35kDa, 21kDa and 17.5kDa in an Echinococcus multilocularis protoscolex extract after Western blotting. In AE cases classed as cured or improved, IgG subclass antibody levels tended to decrease earlier than total IgG levels, especially IgG4 antibody levels which became negative within one year after successful treatment. IgG4 antibody levels also decreased in most of the improved cases. Increasing or unchanged levels of IgG4 and IgG1 antibodies were demonstrated in both stabilized and aggravated AE cases using both ELISA and immunoblot assays. Reappearance of specific IgG4 antibodies was a strong indication of recurrence, especially in liver transplant patients. Combined quantitative and qualitative assessment of IgG1 and IgG4 antibodies may be potentially useful for the serological follow-up of human AE.

Medical technology and inequity in health care: the case of Korea

There has been a rapid influx of high cost medical technologies into the Korean hospital market. This has raised concerns about the changes it will bring for the Korean health care sector. Some have questioned whether this diffusion will necessarily have positive effects on the health of the overall population. Some perverse effects of uncontrolled diffusion of technologies have been hinted in recent literature. For example, there is a problem of increasing inequity with the adoption of expensive technologies. Utilization of most of the expensive high technology services is not covered by national health insurance schemes; examples of such technologies are Ultra Sonic, CT Scanner, MRI, Radiotherapy, EKG, and Lithotripter. As a result, the rich can afford expensive high technology services while the poor cannot. This produces a gradual evolution of classes in health service utilization. This study examines how health service utilization among different income groups is affected by the import of high technologies. It discusses changes made within the health care system, and explains the circumstances under which the rapid and excessive diffusion of medical technologies occurred in the hospital sector.

Physician distribution and health manpower policy in Korea

This research studied the impact of increased physician supply on geographical distribution and identified the variables, both demographic and socio-economic, that account for physician maldistribution between urban and rural areas. Increased physician supply did not necessarily improve physician availability and access to health care in many rural and inner-city areas of Korea. Observed performance indicates that most physicians newly qualified since 1974 chose to work in major urban areas, while most rural areas had a shortage of physicians and health facilities. Physicians also tended to work in areas where there were supportive medical facilities, where the distance to major metropolitan areas was not great, where medical schools were located or nearby, and where consumers lived in pleasant surroundings.

[Statistical analysis of 1016 cases of nervous system tumors in different nationalities in Xinjiang]

1016 cases of tumors of the nervous system in different nationalities in Xinjiang were collected from biopsies and autopsies from 1956 to 1985. The distribution of these tumors by nationalities were 78.93% in Han, 11.02% in Uygur, 5.42% in Hazak and 3.65% in Hui, respectively. Of 1016 cases, 644 were intracranial tumors (63.38%) with a similar distribution as showed above (80.74%, 11.33%, 4.20%, and 3.27%, respectively). Glioma was predominant in the intracranial tumors (46.11%). It was showed that there was a high incidence of tumors of the nervous system in Han and Hazak as compared with the size of their populations. There were some differences in histologic type in different nationalities.

Supply and demand elasticities of physician services: disequilibrium analysis

Numerous empirical works have examined the demand for and supply of physician services during the past 15 years. Almost all simultaneous equation models have used the assumption of an equilibrium condition in the physician services market. The assumption of an equilibrium market for physician services may not be realistic, at least not in the short term, because the cost of physician services is insufficiently flexible or because of the induced demand on the part of physicians. Different market assumptions will result in different model formulations and model estimations, and with different empirical implications of the estimated results.

The paper has used the US aggregate time-series data, 1950 to 1980, to estimate the demand and supply relationship of physician services, similar to the model specified in the Martin Feldstein article, 1 under a disequilibrium physician services market assumption. The maximum likelihood method is used for the empirical estimation. Contrary to Feldstein's earlier findings, the price elasticity of the demand for physicians is statistically significant with expected signs under a disequilibrium condition. The elasticity of supply of physician services is also, as expected, positive and statistically significant. Economic and policy implications are discussed based on these findings. This paper should fill empirically the gap that has been noted by previous researchers on the demand for physician services.