Ischemic preconditioning and nicorandil pretreatment improve donor heart preservation

The present study investigated the effects of ischemic preconditioning (IPC) and nicorandil pretreatment on myocardial storage in a donor heart preservation model. Isolated rat hearts were separated into groups: group 1, non-preconditioned control group; group 2, 2.5 min of normothermic ischemia followed by 15 min of normothermic Langendorff perfusion (one IPC cycle); and group 3, 2 cycles of IPC. All hearts were subsequently stored in University of Wisconsin solution at 4 degrees C for 2, 4 and 6h, and the concentrations of high-energy phosphate metabolites were measured for each time point. Heart function parameters (aortic flow, coronary flow and cardiac output) were measured when the heart was reperfused following the 2, 4 or 6 h of preservation. The effects of nicorandil, an ATP-sensitive potassium channel opener, on heart function following preservation were also evaluated. Nicorandil was injected intravenously before heart harvesting. The results showed that the energy status was well preserved in the IPC groups. The 2-cycle IPC group showed better recovery of heart function following preservation. Pretreatment with nicorandil also improved functional recovery of the heart following preservation. The present study showed that IPC of the rat heart resulted in improved myocardial energy metabolism and functional recovery after hypothermic preservation, and that nicorandil has potential for pharmacological preconditioning in heart preservation for transplantation.

Treatment of deep infection following thoracic aorta graft replacement without graft removal

Deep infection following thoracic aortic replacement constitutes an extremely serious and life-threatening complication, and its treatment remains a challenge to surgeons. We report our experience involving five patients in whom deep infection occurred around the graft. Four of the five patients were treated by emergency surgery and one was treated by elective surgery. Surgical procedures performed including hemiarch replacement in one case, total arch replacement in one case, suspension of aortic valve and ascending aorta replacement in one case, Bentall procedure in one case, and descending aorta re-replacement in one case. Methicillin-resistant Staphylococcus aureus was detected in four patients, methicillin-resistant Staphylococcus epidermidis in one, and Aspergillus in one patient from purulent discharge at the operative site. Reoperative debridement and irrigation drainage were carried out at an early phase of infection. Intermittent irrigation following the reoperation was performed in all cases. In addition, muscle flap filling or omental translocation was carried out in three patients. Although the reported principle of treatment for arterial graft infection is extraanatomical bypass or rereplacement after removal of the infected graft, such procedures may be technically difficult and have a high risk at the thoracic level. Local anti-septic irrigation, administration of antibiotics, and vascular-rich tissue filling are useful procedures, and it appears that it is not always necessary to remove prosthetic grafts.

Urinary bromide levels probably dependent to intake of foods such as sea algae

The purpose of the present study is to examine if the bromide (Br) level in urine (Br-U) varies substantially among adult general populations of either sex or of different dietary habits. For this purpose, morning spot urine samples (about 50 per group) were collected from six groups of people, i.e., one group each of men and women in a city in Japan (thus two groups in Japan) and one group each of women in two urban and two rural areas in central and northeast China (four groups in China). The samples were analyzed for Br by ECD-gas chromatography after derivatization to methyl bromide. Br-U essentially followed a normal distribution. Whereas there was only a marginal difference in Br-U between men (7.7 +/- 2.5 mg/L as an arithmetic mean and arithmetic standard deviation) and women (8.1 +/- 2.9 mg/L) in Japan, and no difference between the urban (2.3 +/- 0.8 mg/L) and rural women (2.6 +/- 1.1 mg/L) in China, the difference between Japanese (8.1 +/- 2.9 mg/L) and Chinese women (2.3 +/- 0.8 mg/L for two cities and 2.6 +/- 1.1 mg/L for two villages) was substantial. A literature survey suggested variation in dietary habits, especially that in sea algae intake, is a possible factor affecting the observed difference in Br-U between the two ethnic groups. Contribution of Br in cereals after fumigation with, e.g., methyl bromide, was also thought to be possible. The implication of difference in background Br-U levels is discussed in relation to biological monitoring of exposure to Br-containing industrial chemicals, such as 1- and 2-bromopropane.

Dietary selenium intake of Chinese adult women in the 1990s

To assess the levels of daily dietary intake of selenium (Se) among the general Chinese population, a series of field surveys were conducted in the 1990s. Samples of 24-h duplicates of foods were collected from 500 participants (300 in 6 cities and 200 from 4 villages). Se levels were determined by microwave digestion followed by inductively coupled plasma-mass spectrometry (ICP-MS), and the measurements were compared with FCT (Food Composition Tables)-based estimates. The average daily intake of Se was 69.2 lg/d (79.9 and 53.1 microg/d in urban and rural areas, respectively) by instrumental determination and 35.1 microg/d (36.7 and 32.7 microg/d) by FCT-based estimation. As the distribution of Se should be uneven within China, the FCT-based estimation is of a limited value and the ICP-MS determination of Se is more accurate and reliable when evaluating the nutritional status of local people. Taking ICP-MS-based values, Se intakes were lower in rural areas than in urban areas, and the intakes of about half of the people in rural areas were less than the Recommended Daily Allowance (RDA) in China of 50 microg/d. The low intake might be resulted from difference in the types of food consumed. Thus, the dietary intake of Se basically meets the recommended RDA in most of urban areas, but insufficiency may be still a nutritional and public health problem in some rural areas.

Primary human herpesvirus 8 infection generates a broadly specific CD8(+) T-cell response to viral lytic cycle proteins

Human herpesvirus 8 (HHV-8) is a recently discovered gammaherpesvirus that is the etiologic agent of Kaposi sarcoma (KS). The natural history of primary HHV-8 infection, including clinical outcome and host immune responses that may be important in preventing disease related to HHV-8, has not been elucidated. The present study characterized the clinical, immunologic, and virologic parameters of primary HHV-8 infection in 5 cases detected during a 15-year longitudinal study of 108 human immunodeficiency virus type 1 seronegative men in the Multicenter AIDS Cohort Study. Primary HHV-8 infection was associated with mild, nonspecific signs and symptoms of diarrhea, fatigue, localized rash, and lymphadenopathy. There were no alterations in numbers of CD4(+) or CD8(+) T cells or CD8(+) T-cell interferon gamma (IFN-gamma) production to mitogen or nominal antigen. CD8(+) cytotoxic T-lymphocyte precursor (CTLp) and IFN-gamma reactivity were detected during primary HHV-8 infection, with broad specificity to 5 lytic cycle proteins of HHV-8 encoded by open reading frame 8 (ORF 8; glycoprotein B homolog of Epstein-Barr virus), ORF 22 (gH homolog), ORF 25 (major capsid protein homolog), ORF 26 (a minor capsid protein homolog), or ORF 57 (an early protein homolog), in association with increases in serum antibody titers and appearance of HHV-8 DNA in blood mononuclear cells. CD8(+) T-cell responses to HHV-8 decreased by 2 to 3 years after primary infection. This antiviral T-cell response may control initial HHV-8 infection and prevent development of disease.

[Advances in the research of penile erection and erection dysfunction]

Recent advances in the research on erectile dysfunction (ED) has more clearly explained the mechanism of penile erection, which is a hemodynamic process involving relaxation of corpus cavernosum smooth muscle and related arterials, and NO-cGMP signaling pathway proven to play an important role on modulating the relaxation of corpus cavernosum smooth muscle. Studies on NOS and PDEs not only provide strong evidence for the clinical treatment of ED, but also provide the chance to develop Sildenafil. Although the gene therapy for ED is still in the laboratory stage by now, it may be one of the effective clinical therapies for ED in future.

Helicobacter pylori pore-forming cytolysin orthologue TlyA possesses in vitro hemolytic activity and has a role in colonization of the gastric mucosa

Hemolysins have been found to possess a variety of functions in bacteria, including a role in virulence. Helicobacter pylori demonstrates hemolytic activity when cultured on unlysed blood agar plates which is increased under iron-limiting conditions. However, the role of an H. pylori hemolysin in virulence is unclear. Scrutiny of the H. pylori 26695 genome sequence suggests the presence of at least two distinct hemolysins, HP1086 and HP1490, in this strain. Previous studies have shown that the in vitro hemolytic activity of H. pylori is reduced when it is coincubated with dextran 5000, suggesting the presence of a pore-forming cytolysin. HP1086 has homology to pore-forming cytolysins (TlyA) from other bacterial species, and the introduction of the cloned H. pylori tlyA gene into a nonhemolytic Escherichia coli strain conferred hemolytic activity. An H. pylori tlyA defined mutant showed reduced in vitro hemolytic activity, which appears to be due to pore formation, as the hemolytic activity of the wild-type strain is reduced to the same level as the tlyA mutant by the addition of dextran 5000. The mutant also showed reduced adhesion to human gastric adenocarcinoma cells and failed to colonize the gastric mucosa of mice. These data clearly suggest a role in virulence for H. pylori TlyA, contrary to the suggestion that hemolytic activity is an in vitro phenomenon for this pathogen.

Acid, helicobacter and immunity: a new paradigm for oesophagogastric cancer

Epidemiological evidence has clearly shown a highly significant relationship between Helicobacter pylori infection and the development of duodenal ulcer and distal gastric adenocarcinoma. Despite H. pylori being a common aetiological factor for both disorders, the two disease phenotypes are virtually mutually exclusive. This indicates that the host response to infection has a pivotal role in determining outcome; these disease phenotypes relate to the effect of infection on gastric acid secretion, duodenal ulcer being closely related to sustained acid secretion whereas gastric cancer follows gastric atrophy and impaired gastric acid secretion. Cancer at the oesophageal junction and that associated with Barrett's oesophagus is now the most rapidly increasing tumour in the gastrointestinal tract. The challenge for the next millennium, therefore, is to try and develop methods for identifying patients at risk of developing oesophagogastric cancer. A common feature in the pathogenesis of both gastric and oesophageal adenocarcinoma is inflammation presenting clinically as gastritis and oesophagitis. The pathway from gastritis to gastric atrophy, dysplasia and carcinoma is thought to be a multi-step process, probably triggered by free radicals within the gastric epithelium and increased exposure to luminal carcinogens. However, it has been unclear as to which aspect of the host response determines whether an individual will move along the neoplasia pathway. Recent work has shown that qualitative aspects of the immune environment in the stomach may account for a substantial part of the phenotypic divergence following H. pylori infection. Interleukin-1 beta polymorphisms relate closely to the propensity for an individual to develop distal gastric cancer and maybe useful for predicting risk in family members. In Barrett's oesophagus, we have recently shown that the immune environment may also be important in determining whether an individual will develop cancer. Although we did not find that Barrett's oesophagus was a profoundly inflammatory condition (unlike esophagitis in the squamous epithelium), where there was evidence of inflammation it was qualitatively different from that of oesophagitis in that a Th-2 response with increased expression of IL-4 predominated in Barrett's, whereas a Th-1 proinflammatory response characterised oesophagitis in squamous epithelium. It seems likely that the specific immune environment within Barrett's metaplasia may be an important driver towards dysplasia and carcinoma. Thus, the immune environment in the stomach and esophagus may be critical in determining whether an individual is at risk of developing neoplastic complications of H. pylori infection and gastroesophageal reflux. Identification of the genetic factors which underpin these responses may ultimately result in development of methods to identify individuals at high risk.

Urban-rural comparison of HBV and HCV infection prevalence in eastern China

The present study was initiated to make an urban-rural comparison of the prevalence of cases positive to hepatitis B and C virus (HBV and HCV, respectively) infection markers in densely populated eastern half of China. For this purpose, 10 survey siles were selected, i.e., six sites in urban areas (the city group; Beijing, Shanghai and four provincial capitals) and four sites in rural areas (the village group; one village each in Jilin and Shandong Provinces, and two villages in Shaanxi Province). About 50 adult women per site volunteered to participate, from whom 494 valid blood samples were collected. Positivities to HBsAg (HBsAg+), anti-HBs (anti-HBs+) and anti-HBc (anti-HBc+) were examined by RIA methods, and that to anti-HCV (anti-HCV+) by either EIA or RIA. Those positive to any one of the three HBV infection markers were taken as HBV infection-positive (HBV+). The prevalence of HBsAg+, HBV+ and anti-HBc+ was 8%, 70% and 2.7% in the city group, and 8%, 65% and 2.0% in the village group, and no significant difference was found between the two groups. The overall prevalence was 8% for HBsAg+, 68% for HBV+, and 2.4% for anti-HCV+. The results were discussed in reference to some 20 papers each on HBV+ and anti-HCV+ prevalence in China published since 1991. The reviewing of these papers confirmed that the prevalence of HBV was high (i.e., in excess of 50%), whereas the prevalence of anti-HCV was low (well below 5%), and that no substantial difference was found between the rural and urban populations.

Topoisomerase I inhibitor (camptothecin)-induced apoptosis in human gastric cancer cells and the role of wild-type p53 in the enhancement of its cytotoxicity

Camptothecin (CPT), a human topoisomerase I inhibitor, blocks DNA replication in human cancer cells. It represents a promising new class of chemotherapeutic agents with broad anti-tumor activity. However, its effect on gastric cancer cells remains unknown. We examined cell growth, apoptosis and cell cycle phase distribution in gastric cancer cells by exposing these cells to CPT for up to 72 h. Cell viability was determined by the Trypan blue exclusion assay. Cell cycle phase distribution and apoptosis were measured using flow cytometry, fluorescence microscopy and DNA ladder assay. Exposure of exponentially growing gastric AGS cancer cells to CPT induced time-dependent apoptosis and growth inhibition. Serum starvation-synchronized AGS cells (about 60% cells in G0/G1 phase) showed similar cellular responses. Analysis of cell cycle phase distribution of AGS cells treated with CPT for up to 72 h showed no obvious differences compared to untreated control cells. Although the induction of apoptosis was noticed in gastric cancer cell lines both with and without p53, cells lacking p53 showed less apoptosis compared to those cell lines possessing p53. Our data show that CPT is capable of inducing gastric cancer cell growth inhibition and apoptosis. Wild-type p53 may enhance the cytotoxicity of CPT against gastric carcinoma.

Nutrient intake of adult women in Jilin Province, China, with special reference to urban-rural differences in nutrition in the Chinese continent

OBJECTIVES

The objectives of this study were to investigate possible urban-rural differences in food intakes in Jilin province and in continental China as a whole, and to examine possible implications for nutritional status of urban and rural populations.

DESIGN

Cross-sectional study.

SETTING

Communities.

SUBJECTS

In total, 499 adult women in six urban sites and four rural sites, 10 sites in total, including two sites in Jilin province.

METHODS

A pair of surveys were conducted in September, 1999, in the provincial capital of Changchun and a farming village in Dehui county, both in Jilin province, in northeast China. Each of 50 adult women per survey site provided a 24 h duplicate food sample and a blood sample, and had an interview on health history including anthropometry and blood pressure measurement. Nutrient intakes were estimated from the food duplicates, using national food composition tables. Results from the two sites were supplemented with data from eight sites where surveys had been conducted following the same protocol, and the pooled material were subjected to analyses for possible urban-rural differences.

RESULTS

The Jilin participants consumed daily, on average, about 1600 kcal energy, 44 g protein, and 60 g lipid with a lipid energy ratio (i.e. the ratio of lipid over total nutrients in terms of energy) of 33%. When nutrient intakes were compared between the urban (i.e. Changchun) and rural (Dehui) groups, urban women consumed more energy, protein (especially animal protein) and lipid than rural women. Similar examination of data from six urban and four rural sites, including the present two, showed that adult women in urban areas eat more animal protein and animal fat than their counterparts in villages, and suggested that the observation on urban rural difference in Jilin province can be extrapolated to a nationwide scale.

CONCLUSIONS

Urban rural differences in nutrient intakes still persist in 1999 not only in Jilin but in other provinces, typically in the terms of intakes of animal-based foods.

Comparative assay of Hepatitis B and C virus infection markers by different assay kits

In order to compare sensitivity of EIA and RIA assay kits for hepatitis B and C virus (HBV and HCV, respectively) infection markers, 100 serum samples in total were collected form 50 adult women each in urban and rural areas in northeast China. The number of positive cases to the three infection markers on HBV (i.e., HBsAg+, anti-HBs+, and anti-HBc+) and the one on HCV (anti-HCV+) were examined in two laboratories, i.e., in Laboratory A with EIA kits produced in China and in Laboratory B with RIA kits. HCV infection positivity (anti-HCV+) was examined by EIA kits in both laboratories, but from different sources in and outside of China, respectively. The assay in Laboratory A gave 2 HBsAg+ cases out of the 100 cases examined, whereas there were 9 positive cases in Laboratory B. In contrast, 19 cases were positive to anti-HCV when examined in Laboratory A, and there were 3 cases in Laboratory B. Thus, the kits used in Laboratory A gave fewer HBsAg+ and more anti-HCV+ cases than the kits used in Laboratory B. The prevalence of anti-HBs+ or anti-HBc+ and cases did not differ when assayed in the two laboratories with EIA and RIA kits, respectively. The agreement of positive and negative findings between the two sets of testing were 93%, 93%, 93%, 86% and 82% for HBsAg, anti-HBs, anti-HBc, HBV (i.e., either positive to anyone of the three markers or negative to all three markers), and anti-HCV, respectively. The implication of the observation on epidemiology on HBV and HCV infection prevalence was discussed.

Hepatitis B and C virus infection among adult women in Jilin Province, China: an urban-rural comparison in prevalence of infection markers

Twin seroepidemiological surveys on prevalence of hepatitis B and C virus (HBV and HCV, respectively) infection were conducted on 100 adult women in total, 50 each in the provincial capital of Changchun and in a farming village in the vicinity in Jilin Province, northeast China. Positivity to three markers on HBV (ie HBsAg+, anti-HBs+, and anti-HBc+) was examined by RIA methods, and to one on HCV (anti-HCV+) by EIA. The results were evaluated in combination with two foregoing studies in Shandong and Shaanxi Provinces, and with special reference to possible urban-rural differences in prevalence. The prevalence of HBsAg+ cases was rather low (ie 9% when two groups were combined), but that of anti-HBs+ and anti-HBc+ cases was high, being 50% and 45%, respectively. Thus, the rate of HBV+ cases was 62%. The rate for HCV+ cases was 3%. The comparison of the prevalence between the city group and the village group showed that the rates for anti-HBs+ and HBV+ were significantly or marginally higher in the former group than in the latter, respectively. The HCV+ prevalence rate for the city group (4%) also tended to be higher than the corresponding rates for the village group (2%), although the difference was statistically insignificant. When evaluated together with the observation in Shandong and Shaanxi Provinces, it appears possible to generalize that the HBV infection prevalence is not higher and probably lower in rural areas than in urban areas, and that such may also be the case for the HCV infection prevalence.

Possible metabolic interaction between hexane and other solvents co-exposed at sub-occupational exposure limit levels

OBJECTIVE

To investigate whether metabolic interactions exist between hexane (HEX) and other solvents when co-exposed at the levels below occupational exposure limits.

METHODS

Workers, 219 men in ten workshops in total, volunteered to participate in the study. They were occupationally exposed to mixtures of HEX and one or more of toluene (TOL), ethyl acetate (EA) and acetone (ACE). Time-weighted average intensity of vapor exposures was monitored by diffusive personal sampling. 'Free'- and 'total'-2,5-hexanedione (HD) levels in the end-of-shift urine samples were determined by gas chromatography (GC) before and after acid hydrolysis of urine, respectively, and expressed as observed (HDob) or after correction for creatinine concentration (HDcr) or urine specific gravity (HDsg). Possible interaction was examined by multiple regression analysis (MRA), taking either free- or total-HD as a dependent variable, and the four solvent concentrations as independent variables.

RESULTS

In most cases, exposure intensity did not exceed the current occupational exposure limits even when additiveness was assumed. In addition that HEX was the most influential independent variable in all cases as expected, the MRA showed that, in cases of free-HD, ACE was also influential to HDob although weakly, but not to HDcr or HDsg. With regard to total-HD, ACE was weakly influential to HDob and HDsg, and EA also weakly to HDcr. The effect of ACE on free- or total-HD was not detected, however, when 22 men exposed only to HEX and ACE were subjected to the same analysis. Similarly, the effect of EA on total-HD was not observed among the remaining 197 men exposed to HEX, TOL and EA only.

CONCLUSIONS

When the exposures were below occupational exposure limits, the free-HD levels in urine after HEX exposure will not be modified by co-exposures to TOL, EA or ACE.

Exposure of women in general populations to lead via food and air in East and Southeast Asia

BACKGROUND

Despite increasing public concern of the possible health effects of lead (Pb) on general populations, reports on Pb levels in blood (Pb-B) and urine (Pb-B), as well as Pb intake via foods (Pb-F) for many Asian countries are scarce. The present study was initiated to elucidate the extent of non-occupational Pb exposure among general populations in East and Southeast Asia.

METHODS

In 1991-1997, peripheral blood, morning spot urine and 24-hour food duplicate samples were collected from 20 to 50 non-smoking adult women in each of four cities in Southeast Asia and five cities in Mainland China, and two cities each in Japan and Korea. The samples were wet-ashed and then analyzed by inductively coupled plasma mass spectrometry for Pb-B, Pb-U and Pb-F. Measures after logarithmic conversion were subjected to ANOVA and regression analysis.

RESULTS

Geometric mean values in cities in East and Southeast Asia were in ranges of 32-65 microg/L for Pb-B, 2.1-7.5 microg/g cr for Pb-Ucr, and 7-32 microg/day for Pb-F. The values for a combination of two cities of Tokyo and Kyoto, Japan (38 microg/L for Pb-B and 9.3 microg/day for Pb-F) appeared to be lower than the values for other Asian cities, and the values for all Japan (thus including both urban and rural areas) were even lower (19 microg/L for Pb-B and 7.7 microg/day for Pb-F). Comparison of Pb uptake via respiratory and dietary routes showed that Pb via dietary route accounted for 15% of the total in Manila where Pb in air was high (ca. 650 ng/m(3)), whereas it was 54% in Tokyo+Kyoto where Pb in air was low (ca. 75 ng/m(3)).

CONCLUSIONS

When compared internationally, Pb-F and Pb-B in Asia in general are similar to or somewhat higher than the levels in Europe and USA, whereas the levels in Japan are probably lower than the two latter areas. In Asia, Pb-F accounted for 15-54% of all Pb sources, the percentage being variable depending on local conditions especially Pb in atmospheric air.

Gastric alpha-tocopherol and beta-carotene concentrations in association with Helicobacter pylori infection

OBJECTIVE

The effects of Helicobacter pylori infection and its associated gastric histology on alpha-tocopherol and beta-carotene concentrations in serum, gastric juice and antral mucosa were investigated in patients undergoing routine gastroscopy for investigation of dyspepsia.

METHOD

Eighty-six patients were studied. High-performance liquid chromatography was used to measure alpha-tocopherol and beta-carotene concentrations. H. pylori infection was assessed by histology, bacterial culture, rapid urease test and serology.

RESULTS

No obvious association was found between age, sex, smoking or endoscopic diagnosis and alpha-tocopherol or beta-carotene concentrations in serum, gastric juice and antral mucosa. However, alcohol drinkers had significantly lower antral mucosal and gastric juice beta-carotene concentrations compared to non-drinkers. Gastric juice beta-carotene concentration was markedly lower in patients infected with H. pylori than uninfected controls (2.9 nmol/l (interquartile range 0.3-4.3) versus 4.6 nmol/l (interquartile range 3.5-7.6), P = 0.01), but there was no significant difference in serum or gastric mucosal beta-carotene concentrations between the two patient groups. The presence of gastric atrophy and intestinal metaplasia was significantly associated with reduced mucosal alpha-tocopherol and beta-carotene concentrations. Furthermore, antral mucosal alpha-tocopherol concentrations decreased progressively as antral mucosal histology changed from normal to chronic gastritis alone and finally to atrophy and intestinal metaplasia.

CONCLUSION

Gastric alpha-tocopherol and beta-carotene concentrations are affected by H. pylori-associated gastric histological changes, and these findings suggest that H. pylori infection may not only impair the protective role of vitamin C, but also of alpha-tocopherol and beta-carotene in the stomach.

Monitoring of occupational exposure to tetrachloroethene by analysis for unmetabolized tetrachloroethene in blood and urine in comparison with urinalysis for trichloroacetic acid

OBJECTIVE

The present study was initiated to examine a quantitative relationship between tetrachloroethene (TETRA) in blood and urine with TETRA in air, and to compare TETRA in blood or urine with trichloroacetic acid (TCA) in urine as exposure markers.

METHODS

In total, 44 workers (exposed to TETRA during automated, continuous cloth-degreasing operations), and ten non-exposed subjects volunteered to participate in the study. The exposure to vapor was monitored by diffusive sampling. The amounts of TETRA and TCA in end-of-shift blood and urine samples were measured by either head-space gas chromatography (HS-GC) or automated methylation followed by HS-GC. The correlation was examined by regression analysis.

RESULTS

The maximum time-weighted average (TWA) concentration for TETRA-exposure was 46 ppm. Regression analysis for correlation of TETRA in blood, TETRA in urine and TCA in urine, with TETRA in air, showed that the coefficient was largest for the correlation between TETRA in air and TETRA in blood. The TETRA in blood, in urine and in air correlated mutually, whereas TCA in urine correlated more closely with TETRA in blood than with TETRA in urine. The TCA values determined by colorimetry and by the GC method were very similar. The biological marker levels at a hypothetical exposure of 25 ppm TETRA were substantially higher in the present study than were the levels reported in the literature. Possible reasons are discussed.

CONCLUSIONS

Blood TETRA is the best marker of occupational exposure to TETRA, being superior to the traditional marker, urinary TCA.

Urban population exposure to lead and cadmium in east and south-east Asia

Information is still scarce for many Asian countries on general population exposure to two potentially toxic heavy metals of lead (Pb) and cadmium (Cd). The present review on publications from this study group is intended to provide an overview of the non-occupational exposure to Pb and Cd among general populations in east and south-east Asia. During the period of 1991-1998, surveys were conducted in four cities in south-east Asia, five cities in mainland China, and two cities each in Japan and Korea. Peripheral blood, morning spot urine and 24-h food duplicate samples were collected from 20-50 non-smoking adult women in each survey site. The samples were digested by heating in the presence of mineral acids, and then analyzed by inductively-coupled plasma mass spectrometry for the metals in blood (Pb-B and Cd-B), in urine (Pb-U and Cd-U), and in food duplicate (Pb-F and Cd-F). Measures were subjected to statistical analysis with an assumption of log-normal distribution. Pb-B, Pb-U and Pb-F levels varied substantially among the 11 urban sites; GM distributed in ranges of 32-65 microg/l for Pb-B, 2.1-7.5 microg/g cr (creatinine) for Pb-U, and 7-32 microg/day for Pb-F. The same was also the case for Cd exposure parameters, the distribution ranges being 0.5-1.8 microg/l for Cd-B, 1.2-3.1 microg/g cr for Cd-U, and 5-32 microg/day for Cd-F. It appeared that the exposure to Pb and Cd was highest in Kuala Lumpur, and Tokyo + Kyoto, respectively, and lowest in Tokyo + Kyoto and in Manila. Additional surveys in Japan showed that Pb exposure was even lower in rural areas than in Tokyo + Kyoto. When compared with the values reported in the literature, Pb exposure levels among Asian populations appear to be similar to the levels in Europe and in the United States, whereas Cd exposure seems to be higher in Asia than in Europe. The contribution of the dietary route in Pb absorption was variable and was inversely related to the extent of air pollution, whereas Cd uptake was almost exclusively via the dietary route with little contribution of the respiratory route.

Correlation between urine and blood concentrations, and dietary intake of cadmium and lead among women in the general population of Japan

OBJECTIVE

To examine whether lead (Pb) in urine and cadmium (Cd) in blood, especially the former, can be used as markers of environmental exposure of general populations to these metals.

METHODS

Between 1991 and 1998, spot urine and peripheral blood samples, together with 24 h duplicates of food intake were collected from 607 non-smoking adult women in 30 survey sites (SS) in seven administrative regions all over Japan. Urine, blood and food duplicate samples were analyzed by inductively-coupled plasma spectrometry, for Cd and Pb in urine (Cd-U and Pb-U), in blood (Cd-B and Pb-B) and in food duplicates (Cd-F and Pb-F). Correlation between the measurements was examined by regression analysis.

RESULTS

The Cd-B correlated closely with Cd-U, and both Cd-B and Cd-U with Cd-F, on an individual basis (n = 607), on an SS basis (n = 30) and on a regional basis (n = 7). The Pb-U however did not correlate with Pb-B on a regional basis although they correlated with each other when analyzed on an individual as well as SS basis. Moreover, the correlation coefficients between Pb-U and Pb-B were much smaller than those between Cd-U and Cd-B. Neither Pb-U nor Pb-B showed significant correlation with Pb-F on any levels of statistical analysis.

CONCLUSIONS

Both Cd-B and Cd-U can be employed as biomarkers of environmental Cd exposure. The reliability of Pb-U for use in place of Pb-B appeared to be small.

Normal liver function in women in the general Japanese population subjected to environmental exposure to cadmium at various levels

OBJECTIVES

Whereas it is well established that environmental exposure to cadmium (Cd) may induce kidney dysfunction, less attention has been paid to the possible disturbance of liver function by Cd exposure. The possibility that liver function is adversely affected by current levels of environmental exposure to Cd as investigated in women in the general population in Japan, where the background level of exposure to Cd is known to be high.

METHODS

From 1991 to 1997, 24-h food duplicate, peripheral blood and morning spot urine samples were collected from 607 non-smoking and non-habitually drinking women (age range 19-78 years) at 30 survey sites (with no known environmental pollution from heavy metals) throughout Japan. Liver function parameters in serum were examined by conventional methods. After wet-ashing, the food duplicate, blood and urine samples were analyzed for Cd intake via food (Cd-F), Cd in blood (Cd-B), and Cd in urine (Cd-U) by inductively-coupled plasma mass spectrometry.

RESULTS

The geometric mean values for Cd-F, Cd-B, and Cd-U were 24.7 (27.1) microg/day, 1.76 (2.07) microg/l, and 3.94 (4.61) microg/g creatinine (values in parentheses for 41- to 60-year-old women), respectively. It as found that the three parameters of ALP, ALT, and AST activity were positively and significantly related to the age of the subjects (whereas no association as detected in cases of gamma-GTP, LAP, and albumin). Accordingly, a further analysis as made with 367 women selected by age (41-60 years; about 60% of the total population). Essentially, no Cd dose-dependent changes in liver function parameters were observed in the selected population of this narrower age range.

CONCLUSIONS

Overall, it seemed prudent to conclude that liver function as not disturbed by the current environmental exposure to Cd in Japan.

Further reduction in lead exposure in women in general populations in Japan in the 1990s, and comparison with levels in east and south-east Asia

OBJECTIVE

The objective of the study was to elucidate the current level of environmental lead (Pb) exposure of women in general population in Japan, where the use of organic Pb in automobile gasoline was phased out from 1973 to reach a zero level early in the 1980s.

METHODS

A survey was conducted in 27 sites throughout Japan from 1991 to 1997. Five hundred and eighty-eight non-smoking women from the sites offered 24-h food duplicate, peripheral blood, and spot urine samples. Pb in food duplicates (Pb-F), blood (Pb-B), and urine (Pb-U) were analyzed by inductively-coupled plasma mass spectrometry. The results of Pb-F and Pb-B were compared with observations from a study conducted from 1977 to 1981 on 339 women at the same sites. Log-normal distribution was assumed for the evaluation of the results.

RESULTS

Geometric means (GMs) of Pb-F, Pb-B, and Pb-U in the 1991-1997 study were 9.0 microg/day, 20.2 microg/l, and 2.18 microg/g creatinine, respectively. The values for Pb-F and Pb-B were substantially lower than the values (32.8 microg/day for Pb-F and 31.7 microg/l for Pb-B) obtained in the 1977-1981 study, which were already low when compared internationally. Cd-U values in the period from 1991 to 1997 also appeared to be among the lowest in the world. Analysis for time-dependent changes in Pb-U was, however, not possible at the time of this study because no values were available for the period from 1977 to 1981.

CONCLUSIONS

Substantial reductions from 1977-1981 levels in environmental Pb exposure were observed among the study populations in Japan. Current exposure levels appear to be lower than those in other parts of Asia, the USA, and Europe.

Nutrient intake of working women in Bangkok, Thailand, as studied by total food duplicate method

OBJECTIVES

To establish a general view of food habits in Thailand, and to make a quantitative assessment of rice dependency of Thai people.

DESIGN

Cross-sectional study.

SETTING

Community.

SUBJECTS

52 non-smoking and non-habitually drinking adult women in Bangkok participated in the study.

METHODS

The participants offered 24 h food duplicates and peripheral blood samples, and underwent clinical examination including anthropometry. The duplicates were subjected to nutritional evaluation taking advantage of the Thai food composition tables (FCTs), and analyzed for eight nutrient elements by inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

The participants took 1630 kcal from 55 g protein (63% from animal sources), 57 g lipid (mostly from vegetable oil), and 224 g carbohydrate (60% from rice) daily. Nutrient intake at lunch was as large as that at dinner. About a half of the women had insufficient energy intake (ie <80% RDA) whereas 4% had an excess (>120%). Protein intake was sufficient in most cases, whereas lipid intake was in excess in more than a half of the women. Ca, Fe, Mg, Zn and possibly P intakes were below the RDA values in many participants. FCT-based estimates agreed well with the ICP-MS measures in cases of Fe and Ca but tended to be greater than the measures by 50% with regard to P.

CONCLUSIONS

Lunch as substantial as dinner for Thai urbanites. There was a marked dependency on rice as an energy source. Whereas protein intake is generally sufficient, the intake of Ca (and to a lesser extent Fe) was insufficient in a majority of the study participants.

SPONSORSHIP

Dai-ichi Mutual Life Insurance, Japan; the Ministry of Health and Welfare, the government of Japan.

Background lead and cadmium exposure of adult women in Xian City and two farming villages in Shaanxi Province, China

The objectives of the present study are: (a) to clarify the current levels of environmental exposure to lead (Pb) and cadmium (Cd) in Shaanxi Province in China in comparison with levels in other parts of mainland China; (b) to examine if there is any urban-rural difference in Pb and Cd exposure; and (c) to quantify the role of cereals as the dietary source of environmental exposure to these metals. For this purpose, triplet surveys on lead and cadmium exposure were conducted in the provincial capital of Xian and two farming villages A and B in Shaanxi Province, China in 1997. The grand geometric mean for lead (Pb) intake via foods (Pb-F), Pb in blood (Pb-B) and Pb in urine as corrected for creatinine concentration (Pb-Ucr) were 30 micrograms/day, 33 micrograms/l and 5 micrograms/g creatinine, respectively, with significant differences among the survey sites, e.g. Pb-B being higher in Xian (43 micrograms/l) than in the two villages (38 and 22 micrograms/l). The counterpart values for cadmium (Cd) intake via foods (Cd-F), Cd in blood (Cd-B) and Cd in urine (Cd-Ucr) were 6.1 micrograms/day, 0.46 microgram/l and 2.8 micrograms/g creatinine, respectively, with no substantial inter-survey site difference. Thus, it was possible to conclude that, from comparison with the values reported in 1990s literature, the exposure of Shaanxi people to Pb and Cd is no higher than, and even possibly lower than, the levels reported for people in other parts of mainland China. The exposure to Cd was almost exclusively from foods, whereas the exposure to air-borne Pb was large enough in Xian to explain higher Pb-B and Pb-Ucr than the level in Village B despite lower Pb-F in Xian than in Village B. Cereals (wheat, rice, maize and foxtail millet) contributed 26 and 84% of dietary Pb and Cd intake, respectively.

Correlation between concentration in urine and in blood of cadmium and lead among women in Asia

The objectives of the present study are to examine if there exists a quantitative relationship between lead in urine (Pb-U) and that in blood (Pb-B), and also between cadmium in urine (Cd-U) and that in blood (Cd-B) among the general populations who are environmentally (and not occupationally) exposed to these elements at various levels. For this purpose, peripheral blood and morning spot urine samples were collected in 1991-1998 from approximately 50 non-smoking adult women each in four cities in south-east Asia and five cities in mainland China, and two cities each in Japan and Korea. The samples were wet-ashed and then analyzed by inductively-coupled plasma mass spectrometry for Pb-B, Cd-B, Pb-U and Cd-U. Measured values were subjected to analysis to detect possible correlation between the pairs of parameters. A significant correlation between Pb-B and Pb-U was observed when the intensity of Pb exposure (as expressed by Pb-B) was relatively high so that the correlation was significant in all cases studied when Pb-B level was, e.g. 50 microg/l or above. It was also observed that the correlation between Cd-B and Cd-U was significant when Cd-B was, e.g. > 1 microg/l. Thus, it is possible to deduce that, in environmental health, Pb-B and Cd-U levels can be estimated on a group basis from Pb-U and Cd-B, respectively, when Pb and Cd exposure levels are relatively high, e.g. with Pb-B and Cd-B of > 50 microg/l and > 1 microg/l.

Possible effects of environmental cadmium exposure on kidney function in the Japanese general population

OBJECTIVES

To examine whether the current level of environmental exposure to cadmium (Cd) is associated with kidney dysfunction among general populations in Japan.

METHODS

A nationwide survey was conducted in Japan from 1991 to 1997 at 30 survey sites (with no known environmental heavy metal pollution), by the collection of 24-h food-duplicate samples, peripheral blood specimens and morning spot urine samples. In practice, 607 non-smoking adult women provided these samples. After being wet-ashed, the samples were analyzed for Cd in food duplicates (Cd-F), in blood (Cd-B) and urine (Cd-U) by inductively-coupled plasma mass spectrometry (ICP-MS). Urine samples were also analyzed for alpha 1-microglobulin (alpha 1-MG), beta 2-microglobulin (beta 2-MG) and retinol-binding protein (RBP), creatinine (cr) and specific gravity. Possible tubular dysfunction in association with Cd exposure was examined by simple, multiple and logistic regression analyses, and comparison among three different Cd-dose groups. To minimize the confounding effects of aging, 367 women from 41 to 60 years old were selected and subjected to the same statistical analyses.

RESULTS

The analysis of a whole population of 607 women showed that alpha 1-MG and possibly beta 2-MG increased as a function of Cd-F, Cd-B and Cd-U. When the analysis was repeated with the selected population of 367 women aged 41-60, the Cd dose-dependent changes in alpha 1-MG and beta 2-MG became less evident. The distribution of the selected population with alpha 1-MG above two low cut-off values of > 4.9 and > 8.4 mg/g cr or with beta 2-MG above the lowest cut-off value of > 400 micrograms/g cr, was biased toward the group with higher Cd-Ucr, but such bias was not significant for both alpha 1-MG and beta 2-MG when higher cut-off values were employed. No bias was detected with RBP. Logistic regression analysis with alpha 1-MG, beta 2-MG and RBP (with cut-off values given above) in combination with age, Cd-F, Cd-B and Cd-Ucr gave essentially the same results.

CONCLUSIONS

The evidence for kidney dysfunction was of borderline significance in the present study population for which geometric mean Cd-F, Cd-B and Cd-U were 24.7 micrograms/day, 1.76 micrograms/l, and 3.94 micrograms/g cr, respectively. The findings might suggest at the same time that the safety margin is small for the Japanese general population regarding environmental Cd exposure.