Long-term wheel-running can prevent deterioration of bone properties in diabetes mellitus model rats

OBJECTIVES

The purpose of this study was to examine the effects of long-term wheel-running on tibia bone properties in T2DM Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

Ten five-week-old male OLETF rats were used as experimental animals and 5 Long-Evans Tokushima Otsuka (LETO) rats as controls. Half of OLETF rats performed daily voluntary wheel-running for 17 months (OLETF-EXE), while neither the remainder of OLETF nor LETO rats had exercise. At the end of experiment, in addition to serum biochemical and bone formation/resorption marker analyses, bone mass, trabecular bone microarchitecture and cortical bone geometry were analyzed in left tibia, and bone mechanical strength of right tibia was measured.

RESULTS

Tibia bone mass, trabecular bone microarchitecture, cortical bone geometry and bone mechanical strength deteriorated in diabetic OLETF rats. However, such deterioration was obviously attenuated in OLETF-EXE rats, which maintained normal levels of blood glucose, HbA1c and blood urea nitrogen.

CONCLUSIONS

Daily wheel-running could prevent the deterioration of bone properties in OLETF rats. This would be induced mainly by suppressing the development of T2DM. Regular physical exercise may be a potent strategy for preventing not only the development of diabetes but also the deterioration of bone properties in patients with chronic T2DM.

Dynamic response of the pulmonary circulation in continuous flow artificial heart systems

Pulmonary circulation dynamics is important when considering bi-ventricular assist devices (BiVAD) or total artificial heart (TAH) systems and in investigating the mechanism of atrial collapse in order to design better control algorithms. In this study, we investigated pulmonary circulation dynamics in a continuous flow artificial heart system by performing acute tests on a mature goat. By varying the right pump speed, we were able to observe the dynamic response of the left atrial pressure (LAP) and simulate conditions that result in atrial suction. The results showed a time constant characteristic of a compliance lag in LAP response to changes in right pump output in the TAH configuration. These results may prove useful in the design of a new mock circulatory system that incorporates the dynamics of the pulmonary circulation, and in the improvement of existing control algorithms that prevent atrial wall collapse.

Importance of intra-individual variation in tumour volume of hepatic colorectal metastases

AIMS

The efficacy of surgical resection for multiple colorectal hepatic metastases (MCHM) has been controversial. We examined the survival of patients who received surgery for MCHM and examined the factors associated with survival.

METHODS

A retrospective analysis was performed of 50 consecutive patients who received hepatic resections for MCHM, defined as four or more metastatic lesions of colorectal cancer.

RESULTS

Overall survival after hepatic resection for MCHM was 48% at 3years and 43% at 5years (median survival, 22.3months). Multivariate analyses revealed that a coefficient of variation (CV) in volume of hepatic metastases in each individual patient above 1.8 (P=0.01, HR=4.08, 95% CI=1.33-12.5) was the only poor prognostic factor after resection of MCHM.

CONCLUSIONS

A CV in volume of hepatic metastases in each individual patient above 1.8 predicts poor survival after hepatectomy of MCHM. Thus, the CV in volume of hepatic metastases in each individual patient might be useful in planning the therapeutic strategy for patients with MCHM.

Fish intake and serum levels of organochlorines among Japanese women

This study evaluates background serum levels of selected organochlorine compounds among Japanese women of reproductive age and investigates whether lifestyle factors, especially dietary factors, may be associated with these levels. A cross-sectional study was performed on 80 Japanese women, aged 26-43 years, who complained of infertility and were confirmed not to have endometriosis. The serum levels of total toxic equivalency (TEQ), 18 polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs), 4 coplanar polychlorinated biphenyls (cPCBs), 36 ortho-substituted polychlorinated biphenyls (PCBs), and 13 chlorinated pesticides or their metabolites were measured and data were collected on the women's age, residence, occupation, body mass index (BMI), smoking and alcohol habit and 6 dietary intakes (fish, meats, rice, vegetables, fruits and dairy products). The serum median level of total TEQ was 25.1 pg TEQ/g lipid, that of PCDDs/PCDFs/cPCBs was 11.5 pmol/g lipid, that of PCBs was 0.46 nmol/g lipid, and that of total pesticides was 1.32 nmol/g lipid. The serum levels of total TEQ, PCDDs/PCDFs/cPCBs, PCBs and pesticides were positively associated with age (P for trend=0.003, 0.01, 0.005 and 0.01, respectively) and frequent fish consumption (P for trend=0.002, 0.003, 0.0003 and 0.006, respectively). Other lifestyle factors were not associated with serum organochlorine levels. The present study suggests that Japanese women who consume fish frequently in their reproductive period tend to accumulate organochlorines in their bodies.

Microalgal cultivation in a solution recovered from the low-temperature catalytic gasification of the microalga

Microalgal cultivation in a solution recovered from the low-temperature catalytic gasification of the microalga itself was studied. The growth of Chlorella vulgaris in 75-300-fold diluted recovered solution containing phosphate, magnesium ions and micro-elements was comparable to that in the standard culture medium. It was suggested that C. vulgaris could use ammonium in the recovered solution as its nitrogen source and at the same time could provide a source of biomass which was recycled via gasification.

Association between endometriosis and genetic polymorphisms of the estradiol-synthesizing enzyme genes HSD17B1 and CYP19

BACKGROUND

Endometriosis, an estrogen-dependent disease, is believed to be influenced by multiple genetic and environmental factors. Here, we evaluated whether the risk and severity of endometriosis are associated with polymorphisms in estradiol-synthesizing enzyme genes: the Ser312Gly polymorphism in 17-beta-hydroxysteroid dehydrogenase type 1 (HSD17B1) and the Arg264Cys polymorphism in cytochrome P450, subfamily XIX (CYP19).

METHODS

All participants underwent diagnostic laparoscopy, and the stage of endometriosis was determined according to the Revised American Fertility Society classification. Of the 138 women enrolled, 59 had no endometriosis, 21 had stage I, 10 had stage II, 23 had stage III and 25 had stage IV. SNPs were discriminated by allele-specific oligonucleotide hybridization.

RESULTS

Individuals having at least one A-allele (A/G or A/A genotype) of HSD17B1 showed a significantly increased risk of endometriosis (A/G genotype: adjusted OR, 3.06; 95%CI 1.21-7.74; A/A genotype: adjusted OR, 3.02; 95%CI 1.08-8.43). There was a significant trend associating A/G + A/A genotypes with severity of endometriosis (P for trend < 0.01). No statistically significant association was found for the CYP19 polymorphism.

CONCLUSIONS

Evidence for association between the Ser312Gly polymorphism in HSD17B1 and endometriosis was found in a Japanese population. The A-allele of HSD17B1 appears to confer higher risk for endometriosis.

Analytical method of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in human hair by column-switching liquid chromatography–mass spectrometry

A column-switching liquid chromatography-mass spectrometry was developed for quantification of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in human hair. Hair sample was digested in 1N NaOH at 100 degrees C, and PhIP was extracted using a Blue-Chitin column. The recovery rate was 73%, the limit of quantification was 50 pg/g hair, and intra-day and inter-day variations were 6.3 and 11.7%, respectively. PhIP was found in 42 of the 46 hair samples from 23 healthy volunteers: 110-3878 pg/g hair. The intrapersonal correlation between the first and second analyses was r = 0.85 (95% confidence interval, 0.65-0.94). A positive correlation was observed between PhIP levels and melanin content in hair. This study indicates the ability of this method to detect levels of PhIP in hair.

Leukocyte 8-hydroxydeoxyguanosine and aromatic DNA adduct in coke-oven workers with polycyclic aromatic hydrocarbon exposure

OBJECTIVE

To investigate the potential for exposure to polycyclic aromatic hydrocarbons (PAHs) to induce oxidative DNA damage, we conducted a cross-sectional study in coke-oven workers employed at an iron-steel factory.

METHODS

The study population contained 119 coke-oven workers from different work areas of the oven and 38 controls. Personal information on age, employment duration, smoking habit and alcohol consumption was obtained at an interview. Leukocyte 8-hydroxydeoxyguanosine (8-OHdG) was measured by high performance liquid chromatography with electrochemical detection. Leukocyte aromatic DNA adducts as effective dose, and urinary 1-hydroxypyren as internal dose, were also measured, and used to analyze the relationship of 8-OHdG with other biomarkers for PAH exposure, tobacco smoke and alcohol consumption.

RESULTS

The leukocyte 8-OHdG revealed a wide inter-individual variation. The highest 8-OHdG level was detected in bottom-workers of the coke-oven. There were significant differences among the four different work areas ( P=0.02). We could not find significant correlation between 8-OHdG levels and urinary 1-hydroxypyrene, but a weakly positive correlation was found between 8-OHdG and leukocyte aromatic DNA adducts among all subjects (r=0.19 P=0.03). We could not observe any effect of smoking and alcohol drinking on 8-OHdG production.

CONCLUSION

We could not find clear evidence that PAH exposure induces oxidative DNA damage.

Chip ligating human genomic DNA serves as storage material and template for polymerase chain reaction

A chip was developed to store DNA for medical research. The optional restriction site fixed on the chip can randomly ligate with whole human genomic DNA treated by the corresponding restriction enzyme. PCR can then use the chip as template DNA. Moreover, a chip fixing two restriction sites (e.g. EcoRI and HindIII) showed the amplification by PCR for any location of genomic DNA. Repetitive PCRs have confirmed that a DNA chip can be stored by at -4 degrees C for 2 years.

[Metastatic lung tumor: report of two cases]

We herein report 2 cases of metastatic lung tumor. The first case was a 59-year-old female, who had undergone a left radical mastectomy for the treatment of breast cancer 18 years before. She was found to have a pulmonary nodule in the left lower lobe on the routine chest radiograph. She underwent a video-assisted thoracic surgery (VATS) partial resection of the left lower lobe. Tumor was diagnosed as a lung metastasis of the breast cancer microscopically. The second case was a 77-year-old man, who had undergone a right nephrectomy for the treatment of renal cell carcinoma. He was found to have 2 nodules in the right lung (1 in the middle lobe and the other in the lower lobe) on the follow-up computed tomography (CT) scan of the chest. He underwent VATS partial resections of the right middle and lower lobes. While the tumor in the lower lobe was diagnosed as a lung metastasis of the renal cell carcinoma, the tumor in the middle lobe turned out a primary lung cancer.

Urinary bisphenol A and plasma hormone concentrations in male workers exposed to bisphenol A diglycidyl ether and mixed organic solvents

AIMS

To evaluate effects of exposure to bisphenol A diglycidyl ether (BADGE) on urinary excretion of bisphenol A, and plasma gonadotrophic hormones and testosterone in male epoxy resin sprayers.

METHODS

Cross sectional study of 42 workers whose job was to spray epoxy resin hardening agents including BADGE and mixed organic solvents, and 42 matched control workers without BADGE use in the same machine plants.

RESULTS

Concentrations of urinary bisphenol A were higher in the epoxy resin sprayers (median 1.06 micro mol/mol creatinine) compared with the controls (median 0.52 micro mol/mol creatinine). Urinary metabolite concentrations of organic solvents used were all higher in the epoxy resin workers compared with the controls. Endocrinological examination showed different concentrations of follicle stimulating hormone (FSH) between the epoxy sprayers (median 5.3 mIU/ml) and the controls (median 7.6 mIU/ml). FSH showed a mild correlation with urinary bisphenol A, but not with the metabolites of organic solvents. Luteinising hormone and free testosterone concentrations did not differ between the two groups.

CONCLUSION

BADGE may generate bisphenol A endogenously. Results suggest that bisphenol A may disrupt secretion of gonadotrophic hormones in men. The clinical significance of endocrine disrupting effects by bisphenol A should be further investigated in male workers exposed to bisphenol A.

Residuals of beta-hexachlorocyclohexane, dichlorodiphenyltrichloroethane, and hexachlorobenzene in serum, and relations with consumption of dietary components in rural residents in Japan

To estimate levels of organochlorine residuals in the Japanese population and the contribution of dietary factors to these levels, we determined serum levels of beta-hexachlorocyclohexane (beta-HCH), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) and p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) in 41 volunteers (14 men and 27 women) in a rural area of Northern Japan. These organochlorine levels were measured using gas-chromatography mass-spectrometry. By a self-administered dietary history questionnaire, the usual dietary intake was estimated. Their median levels (range) were as follows: beta-HCH, 0.50 (0.05-1.50); HCB, 0.20 (0.02-0.70); and total DDT (p,p'-DDE + p,p'-DDT), 5.0 (0.9-31.0) ng/ml serum. Levels of p,p'-DDD were detected in only seven subjects (0.05-0.6 ng/ml serum). The beta-HCH levels were increased with rice and milk intakes, but the least squares means were not simply increased according to the quartile of the intakes. Concerning HCB, fish intake showed a borderline significant correlation (0.20, P = 0.052). In terms of total DDT, intakes of meat, fish, vegetable and milk showed a positive relationship, although none of them provided statistically significant results. No other statistically significant relation between any organochlorines and any food intakes examined was observed in this study. The present study suggests that organochlorine compounds are transported into the human body via foods in the Japanese population. Their effects on health should thus be investigated and monitored.

Vagal stimulation prior to atrial rapid pacing protects the atrium from electrical remodeling in anesthetized dogs

Atrial electrical remodeling is thought to be the cause of the maintenance of atrial fibrillation (AF). Although the initiation and maintenance of AF is partially associated with autonomic nervous tone, vagally mediated AF does not tend to become permanent. Therefore, the effects of preceding vagal stimulation (VS) on the atrial effective refractory period (ERP) under electrical remodeling conditions were investigated in anesthetized dogs. Atrial ERPs were measured at 5 sites before and after a 7-h period of atrial rapid pacing in the control group. In the VS group, the vagus nerve was stimulated for 20 min before a period of atrial rapid pacing. Atrial rapid pacing shortened the ERP at each site in the control group (electrical remodeling). On the other hand, atrial rapid pacing after VS did not shorten the ERP at any site in the VS group. Tetrodotoxin, which was administered into the fatty tissue overlying the right atrial side of the right pulmonary vein junctions, blocked the protective effect of VS against the shortening of the ERP induced by atrial rapid pacing. In contrast, atropine did not interfere with such protective effects. These results suggest that VS prior to atrial rapid pacing protects the atrium from atrial electrical remodeling.

Urinary 1-hydroxypyrene in coke oven workers relative to exposure, alcohol consumption, and metabolic enzymes

OBJECTIVES

To investigate the influence of personal lifestyle--such as smoking and alcohol consumption-on urinary 1-hydroxypyrene (1-OHP) concentrations in coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs) and to evaluate the association of 1-OHP concentrations with the genetic polymorphism of several metabolic enzymes including cytochrome P-450 (CYP) 1A1 and glutathione S-tranferases (GSTs).

METHODS

The study population contained 162 coke oven workers and 58 controls employed at the largest iron and steel factory in China. Personal data were collected at the interview. 1-OHP in urine was measured with high performance liquid chromatography with fluorescence detection. Genetic polymorphisms were identified by the polymerase chain reaction (PCR) method.

RESULTS

A positive association between excretion of urinary 1-OHP and the levels of exposure to PAHs was confirmed. Those people who consumed >or=50 g/day ethanol had significantly higher 1-OHP excretion than did other coke oven workers (p<0.01). No significant difference in urinary 1-OHP was found between smokers and non-smokers, in both controls and exposed subjects. The variant homozygotes at exon 7 of the CYP1A1 gene had significantly higher urinary 1-OHP concentrations than other CYP1A1 genotypes among the exposed workers (p=0.03). There was less association between the concentrations of 1-OHP and the GSTM1, GSTP1, or GSTT1 polymorphism.

CONCLUSIONS

The present study confirmed that urinary 1-OHP is a good biomarker for exposure to PAHs. Alcohol consumption affected urinary 1-OHP excretion. The variant genotypes of the CYP1A1 gene may result in the enhancement of PAH metabolites. It is helpful to understand the role of individual susceptibility on metabolism of carcinogens. These findings suggest that the modulating effect of individual lifestyle factors or genetic nature should be considered in future studies on occupational exposure to PAHs and in evaluating the health risk from harmful chemicals.

hOGG1 exon7 polymorphism and gastric cancer in case-control studies of Japanese Brazilians and non-Japanese Brazilians

Polymorphism of hOGG1 may be capable of serving as a genetic marker for individual susceptibility to various cancers because of its role in the repair of oxyradical DNA damage. We examined the distribution of the hOGG1 Ser326Cys polymorphism and its presumed correlation with gastric cancer risk in two case-control studies of different ethnic groups in São Paulo, Brazil. Potentially eligible Japanese (JB) and non-Japanese Brazilian (NJB) case subjects were defined as patients with newly diagnosed malignant neoplasms of the stomach in 13 hospitals in São Paulo. Ninety-six JBs and 236 NJBs were adopted as subjects. Two controls were matched for each JB case, and one control for each NJB case. The subjects were interviewed using a questionnaire and their blood samples were collected. A significant difference in the distribution of this polymorphism between the two ethnic groups was observed (chi(2)=58.3, P<0.01). The mutant type (Ser/Cys or Cys/Cys) was predominant (approximately 65%) in the JBs, but was only present in approximately 40% of the NJBs. Logistic regression analysis showed no significant increased risk for either the Ser/Cys or Cys/Cys type in either group. The odds ratios of the Cys allele for gastric cancer were 1.01 (95% confidence interval (CI): 0.52-1.93) in the JBs and 0.85 (95% CI: 0.57-1.26) in the NJBs. In the NJBs, a significant increased risk of smoking was shown only in the Ser/Ser type, and no increased risk was shown in the genotypes with the Cys allele. However, no statistically significant interactions were observed with smoking or other possible confounding factors. No statistically significant difference in the distribution of the polymorphism was observed between the intestinal type and diffuse type of gastric cancer in either the JBs or the NJBs. The ethnic difference in hOGG1 Ser326Cys polymorphism was much greater than the case-control difference, and this polymorphism is unlikely to be associated with gastric cancer.

[Clinical study of operated nine thymic carcinomas]

Nine cases of thymic carcinoma (5 males and 4 females) were operated in our hospital between 1990 and 1998. These cases included 4 squamous cell carcinomas, 2 small cell carcinomas, 2 undifferentiated carcinomas and one adenocarcinoma. Preoperative chemotherapy were performed in 3 cases. All cases underwent median-sternotomy followed by mediastinal irradiation, 4 had total resection of the tumor, 2 had subtotal resection and 3 had exploratory thoracotomy followed by mediastinal irradiation. Adjuvant chemotherapy were administered in 4 cases and re-operation were performed in 2 cases. We applied Masaoka's clinical staging for thymoma, nine cases consisted of 6 stage III cases, 2 stage IV b cases and one stage IV a case. Within 2 years after operation, 3 cases (two complete resection cases and one exploratory thoracotomy case) were died of the carcinoma. However, two cases of squamous cell carcinoma have been alive more than 5 years after surgery followed by chemoradiation. The remaining 4 patients are alive either with or without the carcinoma after 7 to 28 months after operation. Thymic carcinoma is not so common mediastinal tumor but is expected to increase in the future. The treatment of thymic carcinoma remains a controversial matter and the survival is poor compared with invasive thymoma, but multimodal-therapy would contribute to improvement of the results in treatment for thymic carcinoma especially in squamous cell carcinoma.

[A breast cancer patient with recurrence in the thoracic wall in whom a high-dose of toremifene was effective]

The patient was a 53-year-old female who presented with a primary complaint of reddening of the left precordial skin. She had undergone mastectomy for cancer of the left breast 12 years and 4 months earlier and had received endocrine chemotherapy including TAM as a postoperative adjuvant therapy. A diagnosis of thoracic wall recurrence was made by chest CT and pathological examination of skin biopsy specimens. Toremifene (TOR) was administrated at 120 mg/day, and PR was maintained for 8 months. Even after the condition became PD, the patient has retained adequate QOL with combination therapies including radiotherapy, and is still treated on an outpatient basis 3 years after the beginning of the treatment.

A preliminary evaluation of intra- and interindividual variations of hOGG1 messenger RNA levels in peripheral blood cells as determined by a real-time polymerase chain reaction technique

The hOGG1 (8-oxoguanine-DNA glycosylase) gene may contribute to further understanding of the relation between oxidative DNA damage and carcinogenesis. A real-time PCR technique was used to determine mRNA levels in peripheral blood cells to assess the possibility of using hOGG1 mRNA as a biomarker in epidemiological studies. To evaluate the intra- and interindividual variation of hOGG1 mRNA levels in peripheral blood cells, we measured them in five healthy nonsmokers three times over a 1-year period. The beta-actin mRNA level in each subject was set equal to 100, and the levels of hOGG1 mRNA were found to range from 1.6-17.6. The intraindividual variation range was 1.8-6.4. Although the difference in the mRNA levels between the sampling dates was not significant (P = 0.73), a significant difference in mRNA levels was found between the subjects (P < 0.01). The subjects seemed to fall into groups according to their individual levels. This preliminary study may provide initial information on the hOGG1 mRNA level of peripheral blood cells as a biomarker in epidemiological studies on oxygen radicals, oxygen radical-related agents, and cancer.

[Assessment of the new TNM classification for resected lung cancer]

To evaluate the revised TNM classification, we investigated the prognoses of 552 consecutive patients who had resection of non-small-cell lung cancer between April 1982 and March 1996. According to the new classification, the 5-year survival rate was 76.9% for stage I A, 57.2% for stage I B (I A versus I B, p < 0.0005), 47.7% for stage IIA, 49.8% for stage IIB, 18.6% for stage IIIA (IIB versus IIIA, p = 0.005), 16.7% for stage IIIB, and 7.9% for stage IV (IIIB versus IV, p = 0.02). Especially for patients in stage I A, there was significant difference in survival between patients with the tumor size within 1.5 cm and those with larger than 1.5 cm. The survival rate for T3N0M0 patients was significantly better than that for T3N1-2M0, but there was no significant difference between patients with T3N0M0 disease and those with T2N1M0 disease. Concerning the pm1 patients, the survival rate was significantly better than other stage IIIB patients. Our results supported the revision for dividing stage I and putting T3N0M0 into stage IIB. However, the classification is controversial about dividing stage II and putting pm1 as T4 disease. Furthermore, subgrouping of T1N0M0 disease by tumor size, T3 by tumor invaded organ will be necessary in the next revisions.

Cytochrome P450 2E1 polymorphism in gastric cancer in Brazil: case-control studies of Japanese Brazilians and non-Japanese Brazilians

Cytochrome P450 2E1 (Cyp2E1) is involved in the metabolic oxidation of carcinogenic nitroso compounds, including N-nitrosoamines. There is an RsaI polymorphism in the transcriptional regulatory region of this gene, and in vitro evidence suggests that the variant type of this polymorphic site has higher transcriptional activity but less chlorzoxazone-metabolizing activity. Interindividual differences in the metabolic capacity of Cyp2E1 are assumed to be associated with cancer susceptibility, but the results of the previous studies on the relation between Cyp2E1 RsaI polymorphism and cancer susceptibility have been inconsistent. Two case-control studies of gastric cancer in Japanese Brazilians (96 cases, 192 controls) and Brazilians not of Japanese ancestry (non-Japanese Brazilians; 236 cases, 236 controls) in São Paulo were designed to clarify the role of the Cyp2E1 RsaI genotype in susceptibility to gastric cancer after considering multifactorial environmental influences. The subjects with variant RsaI genotypes amounted to 47% (28 of 59) and 48% (64 of 133), respectively, of the Japanese cases and controls, and 6% (11 of 187) and 10% (19 of 192), respectively, of the non-Japanese cases and controls. As expected, a difference in the distributions of the two groups was observed. The odds ratio of the RsaI variant genotype of Cyp2E1 was 0.46 (95% confidence interval, 0.21-1.04) in the non-Japanese Brazilian population and 0.98 (95% confidence interval, 0.50-1.90) in the Japanese Brazilian population after adjusting for sex, age, tobacco use, and meat consumption. Additional adjustment for potential confounding factors did not change the odds ratio substantially. No significant interactions were observed between the polymorphism and environmental factors. In regard to the histological type of gastric cancer, the variant genotype was significantly more prevalent than the common genotype in Japanese subjects with diffuse type gastric cancer. Our study suggests that the Cyp2E1 RsaI polymorphism is associated with a reduced risk of gastric cancer, although how the assumed increase in Cyp2E1 expression produced by this polymorphism is related to a reduced risk of cancer remains unclear. The observations in this study are consistent with the recent observations of esophageal cancer in endemic areas of China.

NADE, a p75NTR-associated cell death executor, is involved in signal transduction mediated by the common neurotrophin receptor p75NTR

The low affinity neurotrophin receptor p75NTR can mediate cell survival as well as cell death of neural cells by NGF and other neurotrophins. To elucidate p75NTR-mediated signal transduction, we screened p75NTR-associated proteins by a yeast two-hybrid system. We identified one positive clone and named NADE (p75NTR-associated cell death executor). Mouse NADE has marked homology to the human HGR74 protein. NADE specifically binds to the cell-death domain of p75NTR. Co-expression of NADE and p75NTR induced caspase-2 and caspase-3 activities and the fragmentation of nuclear DNA in 293T cells. However, in the absence of p75NTR, NADE failed to induce apoptosis, suggesting that NADE expression is necessary but insufficient for p75NTR-mediated apoptosis. Furthermore, p75NTR/NADE-induced cell death was dependent on NGF but not BDNF, NT-3, or NT-4/5, and the recruitment of NADE to p75NTR (intracellular domain) was dose-dependent. We obtained similar results from PC12 cells, nnr5 cells, and oligodendrocytes. Taken together, NADE is the first signaling adaptor molecule identified in the involvement of p75NTR-mediated apoptosis induced by NGF, and it may play an important role in the pathogenesis of neurogenetic diseases.

[Efficacy of combined chemoendocrine therapy with doxifluridine, cyclophosphamide, and fadrozole hydrochloride hydrate in a case of stage T4N3M1 breast cancer]

A 66-year-old female presented with a swollen lump in the left breast. She was diagnosed as having advanced breast cancer of stage T4N3 (supraclavicular lymph node) M1 (bone). The administration of CEF and TAM failed to improve her condition. After the treatment regimen was changed to combined chemoendocrine therapy with CPA, EPI, 5'-DFUR, and MPA, the areas of bone metastases were reduced. However, MPA caused side-effects (acute obstruction of the lower limb), and thus the treatment was discontinued after 4 months. Subsequently, the treatment combination was changed to CPA, EPI, 5'-DFUR, and fadrozole hydrochloride hydrate. After one year of the treatment, a complete response (CR) was obtained with the disappearance of the supraclavicular lymph node and bone metastases. After EPI reached the maximum administration amount, the remaining CPA, 5'-DFUR and fadrozole hydrochloride hydrate oral administrations were continued. As of 3 years and 10 months after the onset of the chemoendocrine therapy, CR has been maintained with suppression of the primary and metastatic lesions, without degrading the patient's quality of life.

Aromatic DNA adducts in coke-oven workers, in relation to exposure, lifestyle and genetic polymorphism of metabolic enzymes

OBJECTIVE

This study investigates the effect of multiple factors, including exposure to polycyclic aromatic hydrocarbons (PAHs), lifestyle, genetic polymorphism of cytochrome P450 (CYP)1A1, glutathione transferase (GST)M1, GSTP1, N-acetyltransferase (NAT)2 and gene p53, as well as any family history of cancer, on DNA adduct levels in coke-oven workers.

METHODS

Sixty-five coke-oven workers employed at the largest iron-steel factory in China were recruited for the study. Personal data were collected at the interview. DNA adduct levels in total white blood cells (WBCs) were detected using 32P-postlabeling techniques. Genetic polymorphisms were analyzed by polymerase chain reaction (PCR) methods.

RESULTS

The subjects were divided into low and high exposure groups, according to personal exposure to PAHs. The mean adduct value was 1.57 (range 0.54 to 4.35) per 10(8) nucleotides. A tendency for increased levels of DNA adducts in the high exposure group was observed, compared with the low exposure group (P = 0.07). In the low exposure group, DNA adducts were found to be positively associated with urinary cotinine (r = 0.44, P = 0.01). The rare allele homozygotes of CYP1A1 showed significantly higher DNA adduct levels than those of other CYP1A1 genotypes. Individuals with the NAT2 wild type had significantly increased DNA adduct levels than those with other NAT2 genotypes in the high exposure group. The p53 genetic polymorphism revealed a significantly positive effect on DNA adducts formation. There was a significantly higher adduct level in the subjects with a family history of cancer than those without, in the high exposure category.

CONCLUSIONS

Effects of several variables, such as smoking, genetic polymorphism of 2 CYP1A1, NAT2, and gene p53, and a family history of cancer on DNA adduct levels were found, suggesting that these variables should be considered when evaluating the genotoxic effect of occupational exposure to PAHs using WBCs DNA adducts.

[Metastatic squamous cell carcinoma of hilar lymph node with unknown primary site]

An abnormal shadow was observed on chest X-ray films of a 63-year-old man presenting with cough and sputum. Chest computed tomographic scans disclosed enlargement of the right hilar lymph nodes, but no obvious primary lesion was found in the lung field. Bronchoscopic examination revealed a slightly widened second carina, but no malignant cells were detected by transbronchial aspiration cytology. At surgery, a tumor was found between the truncus superior and the truncus intermedius. The pathologic diagnosis was a metastatic lymph node of poorly differentiated squamous cell carcinoma. Because the tumor severely adhered to the bronchus and pulmonary arteries, we performed a right pneumonectomy with mediastinal node dissection. Pre- and postoperative examinations did not detect the primary lesion, and no recurrence had been observed 76 months after surgery. This was thought to be a very rare case of T0 N1 M0 lung cancer. In general, the prognosis is poor for patients with metastatic carcinoma of unknown primary site. However, patients with T 0 lung cancer, as in this case, might enjoy a better prognosis if complete resection and dissection of metastatic lymph nodes are performed.

[Two cases of the bronchial cyst located in the anterior mediastinum]

Bronchial cysts are common cystic tumors around the tracheobronchial tree in the middle and posterior mediastinum and rarely locate in the anterior mediastinum. We reported two cases of the bronchial cyst located in the anterior mediastinum. One case was a 57 year-old-female. A thymic cyst was suspected and the extended total thymectomy was performed through the mediansternotomy. The microscopic examination showed bronchial epithelium and cartilage in the cystic wall. The another case was 71 year-old-male operated by thoracoscopic surgery for the cystic tumor in the anterior mediastinum. Microscopic examination showed bronchial epithelium and gland in the cystic wall.

[Successful endocrine chemotherapy in patients with multiple bone metastases of breast cancer--a case report]

A 54-year-old woman was admitted to our hospital with upper and lower back pain. She had previously developed multiple bone metastases of advanced breast cancer. Endocrine chemotherapy of tamoxifen citrate (TAM) 20 mg/day and carmofur (HCFU) 300 mg/day was started. Subsequently, medroxyprogesterone acetate (MPA) 600 mg/day and 5'-deoxy-5-fluorouridine (5'-DFUR) 600 mg/day were administered. In evaluating the treatment effect for symptomatic relief, partial response and performance status were judged to have improved from 4 to 2. At present, the patient is able to walk on her own to the hospital. She has lived 4 years with no newly developed lesions, and no adverse effects such as diarrhea or body weight gain have been observed. Substantial results can be achieved in patients with bone metastasis of breast cancer even with mild endocrine chemotherapy. A combination of radiotherapy, pain control, and orthopedic surgery suitable to each case is thought to be necessary.

Acute immunotoxicity of p-chloronitrobenzene in mice: II. Effect of p-chloronitrobenzene on the immunophenotype of murine splenocytes determined by flow cytometry

To evaluate the immunotoxicity of p-chloronitrobenzene (p-CNB), we investigated its effect on the immunophenotype of murine splenocytes. BDF1 male mice were randomly divided into exposed and control groups: the exposed group received p-CNB at 300 mg/kg dissolved in olive oil, while the control group received only olive oil, by a single intraperitoneal (i.p.) or subcutaneous (s.c.) injection. On days 3, 5, 7, and 10 after the injection, splenocytes were harvested from both groups, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (CD45R/B220); (2) T cells (CD3e); (3) T-cell subsets (CD4 and CD8a); (4) natural killer (NK) cells (NK-1.1); (5) macrophages (CD11b; Mac-1); (6) nucleated erythrocytes (Ter-119); and (7) dead cells with propidium iodide (PI). The percentages and numbers of B, T, subsets of T (CD4 and CD8), and NK cells in the exposed mice significantly decreased as compared with the respective control. On the other hand, macrophages (Mac-1+ cells), nucleated erythrocytes (Ter-119+ cells), and dead cells in the exposed mice markedly increased as compared with the respective control after i.p. injection of p-CNB. The above findings indicate that p-CNB has an immunotoxic effect on mice.

Identification of a 5-cM region of common allelic loss on 8p12-p21 in human breast cancer and genomic analysis of the hEXT1L/EXTR1/EXTL3 gene in this locus

The short arm of chromosome 8 is frequently lost in many human carcinomas including breast cancer, suggesting the presence of a tumor suppressor gene(s) in this region. We identified a gene termed hEXT1L/EXTR1/EXTL3 (hEXT1L hereinafter) that was mapped to chromosome bands 8p12-p21 where frequent LOHs of this region was reported in breast cancer. The existence of the third breast cancer susceptibility gene was also suggested in this region by linkage analysis. We further performed LOH analysis in 8p12-p21 in 34 breast cancers and identified a 5-cM region of common allelic loss that overlapped with the locus for positive lod score in familial breast cancer. We further analyzed genomic alterations of hEXT1L in tumors in which frequent LOHs of 8p were reported. A total of 327 cancers (313 primary tumors and 14 cancer cell lines) including 22 primary breast cancers were analyzed, but none of the tumors had somatic mutations: only one thyroid cancer patient without any family history of cancer had a 9-bp insertion in the constitutional DNA. These results suggest that mutations of hEXT1L do not play a major role in the development of sporadic cancers including breast cancer, and that other tumor suppressor gene(s) exists in the 5-cM region identified in this study.

Beneficial effects of prostaglandin E1 on ischemic colitis following surgery on the abdominal aorta

To determine the effects of prostaglandin E1 (PGE1) on the intestinal circulation, an experimental dog model of ischemic colitis following abdominal aortic reconstruction was made by ligating the inferior mesenteric artery (IMA) and the internal iliac artery, with the creation of a 50% stenosis in the superior mesenteric artery (SMA). The parameters of enteric ischemia included the blood flow of the SMA, the tissue blood flow in the small intestine and left colon, the mean stump pressure of the IMA (IMAP), and the IMAP/mean systemic blood pressure ratio. With the continuous infusion of 10 ng/kg per minute of PGE1 into the descending thoracic aorta, these values increased significantly on the seventh postoperative day compared with those on the day of operation. These results thus suggest that the continuous intraarterial infusion of PGE1 may reduce ischemic changes in the colon following abdominal aortic reconstruction.

A study of multiple biomarkers in coke oven workers--a cross-sectional study in China

We conducted a cross-sectional molecular epidemiological study of coke oven workers exposed to the established carcinogen polycyclic aromatic hydrocarbons (PAHs) to evaluate the relationships between both traditional 'exposure markers' and a series of biomarkers, including urinary 1-hydroxypyrene as a marker of internal dose, leukocyte aromatic DNA adducts as markers of biologically effective dose, serum p53 protein as a response marker and genetic polymorphisms of cytochrome P4501A1 and glutathione S-transferase MI as susceptibility markers. Twenty-five male subjects each were randomly selected from the top, middle and bottom work areas of the oven, and the control plant. They were matched for age and smoking status. The mean levels of PAH exposure, monitored by stationary and personal samplers, and of worker urinary 1-hydroxypyrene differed significantly between the top, middle and bottom of the oven and control work areas. The highest stationary and personal PAH concentrations and 1-hydroxypyrene levels were demonstrated at the top work area. Good correlations were found between the stationary PAH levels, personal PAH levels and urinary 1-hydroxypyrene levels. No positive correlations were demonstrated between aromatic DNA adduct levels and current or cumulative PAH exposure dose. In the presence of genetic polymorphisms of cytochrome P4501A1, a positive correlation was demonstrated between aromatic DNA adducts and urinary 1-hydroxypyrene levels. There was also a significant correlation between serum p53 protein levels and the cumulated benzo[a]pyrene exposure dose. Although these biomarkers have certain limitations, they are applicable to cancer epidemiology, and may contribute to our understanding of the mechanisms of carcinogenesis.

[Catamenial pneumothorax under video-assisted thoracoscopic surgery: a case report]

A 46-year-old woman complained four times of chest pains due to repeated right pneumothorax. This was improved by the right thoracic drainage each time. She was diagnosed as having catamenial pneumothorax from the fact that each episode of pneumothorax began with the first day of her menstrual cycle. She was admitted to our hospital in Jan. 1996 and operated on by the obliteration of pleuro-peritoneal fistulas on right diaphragm under video-assisted thoracoscopic surgery (VATS). No other abnormal lesions were found in the right pleural cavity and right lung. In this case, the pathophysiological mechanisms of pneumothorax might have been caused by the air influx from the peritoneal cavity to the right pleural cavity through the fistulas on the right diaphragm. VATS is minimally invasive surgery and very useful for the treatment of pleuro-peritoneal fistulas on the diaphragm. It should be emphasized that hormonal therapy is necessary after VATS of catamenial pneumothorax.