Biomedical subjects

J M Yuan

Publications and source records attributed to J M Yuan.

At least 19 recordsLinked to original sources

PubMed2006

Dietary conjugated linoleic acid enhances spleen PPAR-gamma mRNA expression in broiler chicks.

1. The anti-inflammatory effects of dietary conjugated linoleic acid (CLA) on broilers repeatedly challenged with lipopolysaccharide (LPS) were investigated. 2. Day-old broiler chicks were allotted into three treatment groups and fed on a control diet or diets containing 5.0 or 10.0 g CLA/kg diet. Six chicks from each treatment were injected with LPS (0.25 mg/kg body weight) at 16, 18 and 20 d of age. Splenic cyclooxygenase (COX) and inducible nitric oxide synthase (iNOS) activities, and prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production as well as peroxisome proliferator-activated receptor-gamma (PPAR-gamma) mRNA expression were measured at 21 d of age. 3. Chicks fed 10.0 g CLA/kg diet had lower COX activities and PGE(2) production that the controls. Dietary CLA (10.0 g/kg) did not significantly diminish LPS-induced enhancement of COS-2 activity, inhibited the subsequent increase in PGE(2) production. 4. Regulation of COX-1 activity contributed to the difference in PGE(2) production. 5. CLA did not markedly attenuate the increase of iNOS activity and NO production caused by LPS challenge. Chicks fed CLA had lower iNOS activity and NO production than the controls. 6. Dietary CLA activated splenic PPAR-gamma mRNA expression and increased PPAR-gamma mRNA expression after LPS injection. 7. These results suggest that dietary CLA has immunomodulatory effects in the spleen by restricting basal PGE(2) and NO to lower levels and enhancing PPAR-gamma mRNA expression. During the inflammatory response, dietary CLA did not alleviate the increase in COX-2 and iNOS activities but enhanced PPAT-gamma mRNA expression.

Animal Feed↗

PubMed2005

Solid-state fermentation of cornmeal with the basidiomycete Ganoderma lucidum for degrading starch and upgrading nutritional value.

AIMS: The objective of this research was to study the ability of the basidiomycete Ganoderma lucidum to degrade starch and upgrade nutritional value of cornmeal during solid-state fermentation (SSF). METHODS AND RESULTS: On the basal medium that consisted of cornmeal and salt solution, alpha-amylase activity of G. lucidum reached its maximum value of 267 U g(-1) of culture on day 20 after inoculation. Prolongation of fermentation time from 10 to 25 days increased significantly the degradation rate of starch and ergosterol yield (a kind of physiologically active substances of G. lucidum, also as an indicator of mycelial biomass) (P < 0.01). Supplementation of glucose, sucrose or maltose to the basal medium also caused a significant increase in either the degradation rate of starch or the ergosterol yield as compared with control (P < 0.01). Among five kinds of nitrogen sources supplemented, yeast extract, casamino acid and peptone were more effective than (NH4)2SO4 and NH4NO3, and yeast extract gave the highest degradation rate of starch and ergosterol yield, followed by peptone. Through orthogonal experiments, the theoretical optimum culture medium for SSF of this fungus was the following: 100 g cornmeal, ground to 30-mesh powder, moistened with 67 ml of nutrient salt solution supplemented with 3 g yeast extract and 7.5 g glucose per litre. CONCLUSIONS: Under the optimum culture condition, the degradation rate of starch reached its maximum values of 70.4%; the starch content of the fermented product decreased from 64.5 to 25.3%, while the reducing sugar content increased from 4.2 to 20.6%. SSF also produced a significant increase (P < 0.01) from 11.0 to 16.5% in protein content. SIGNIFICANCE AND IMPACT OF THE STUDY: After SSF by G. lucidum, the digesting and absorbing ratio of cornmeal was strikingly increased and some active substances originated from G. lucidum remained in the fermented product. This implied that cornmeal could be processed into many kinds of special functional foods by SSF of G. lucidum.

Biomass↗

PubMed2005

Effect of oxidative stress and exogenous beta-carotene on sclerotial differentiation and carotenoid yield of Penicillium sp. PT95.

AIMS: To determine the effect of oxidative stress and exogenous beta-carotene on sclerotial differentiation and carotenoid yield of Penicillium sp. PT95. METHODS AND RESULTS: In this experiment, high oxidative stress was applied by inclusion of FeCl(3) (10 micromol l(-1)) in the growth medium and by light exposure. Low oxidative stress was applied by omitting iron from the growth medium and by incubation in the dark. Supplementation of exogenous beta-carotene (as antioxidant) to the basal medium caused a concentration-dependent delay of sclerotial differentiation (up to 72 h), decrease of sclerotial biomass (up to 43%) and reduction of carotenoid yield (up to 92%). On the contrary, the exogenous beta-carotene also caused a concentration-dependent decrease of lipid peroxidation in colonies of this fungus. CONCLUSIONS: Under high oxidative stress growth condition, the sclerotial biomass and carotenoid yield of PT95 strain in each plate culture reached 141 mg and 30.03 microg, which were 1.53 and 3.51 times higher respectively, than that at low oxidative stress growth condition. SIGNIFICANCE AND IMPACT OF THE STUDY: These data prompted us to consider that in order to attain higher sclerotial biomass and pigment yield, the strain PT95 should be grown under high oxidative stress and in the absence of antioxidants.

Antioxidants↗

PubMed2003

Phenobarbital use and bladder cancer risk.

BACKGROUND: Two epidemiologic studies have reported an inverse association between use of phenobarbital (PB) and bladder cancer development. It was proposed that PB use protects against bladder cancer by inducing enzymes that participate in the detoxification of human bladder carcinogens, such as the aminobiphenyls and naphthylamines, which are found in cigarette smoke. METHODS: A population-based case-control study was conducted in Los Angeles, California, involving 815 incident bladder cancer cases and an equal number of controls who were matched to the index cases by neighborhood, sex, date of birth (within 5 years), and race. Detailed information on lifetime use of PB was collected through in-person interviews. RESULTS: Ever use (20 or more times over lifetime) of PB was not associated with risk of bladder cancer (OR: 0.86; 95% CI: 0.54, 1.39). Regular use of PB also was not associated with risk of bladder cancer in either men or women, in either smokers or non-smokers, although the number of regular users in cases and controls were relatively small (21 cases vs. 15 controls, OR: 1.20; 95% CI: 0.59, 2.45). In fact, compared with non-users, subjects in the highest category of lifetime PB consumption were at a non-significant 2.46-fold increased risk of bladder cancer (95% CI: 0.90, 6.78). CONCLUSIONS: The present study did not observe a protective role of PB use in bladder cancer development in the general population.

Age Distribution↗

PubMed2001

IGF-1, IGF-2 and IGFBP-3 in prediagnostic serum: association with colorectal cancer in a cohort of Chinese men in Shanghai.

This is the first study to investigate the associations of IGF-1, IGF-2 and IGFBP-3 concentrations with the risk of colorectal cancer in prospectively collected blood samples from an Oriental population. Between 1986 and 1989 serum samples were collected at baseline from 18 244 men, aged 45-65 years, without a history of cancer and living in Shanghai, China. IGF-1, IGF-2 and IGFBP-3 were measured in the serum of 135 men who developed colorectal cancer over 12 years of follow-up and 661 control subjects drawn from the cohort, who were matched to the index cases by neighbourhood of residence, age, and year and month of sample collection. Serum IGF-1 was not associated with risk of colorectal cancer. IGF-2 and IGFBP-3, on the other hand, exhibited statistically significant, positive associations with colorectal cancer risk when cases were confined to those diagnosed within a relatively short time period after enrollment (within 8 years). After adjustment for body mass index, cigarette smoking and alcohol intake, men in the highest versus the lowest quintile of IGF-2 and IGFBP-3 showed odds ratios of 2.74 (95% Cl = 1.67-4.50; 2-sided P for trend = 0.0008) and 2.85 (95% Cl = 1.69-4.81; 2-sided P for trend = 0.01), respectively. Our data thus suggest that circulating IGF-2 and IGFBP-3 can serve as early indicators of impending colorectal cancer.

Alcohol Drinking↗

PubMed2001

Fish and shellfish consumption in relation to death from myocardial infarction among men in Shanghai, China.

Between 1986 and 1989, 18,244 men aged 45-64 years in Shanghai, China, participated in a prospective study of diet and cancer. All participants completed an in-person, structured interview and provided blood and urine samples. As of September 1, 1998, 113 deaths from acute myocardial infarction were identified. After analyses were adjusted for age, total energy intake, and known cardiovascular disease risk factors, men who consumed >or=200 g of fish/shellfish per week had a relative risk of 0.41 (95% confidence interval: 0.22, 0.78) for fatal acute myocardial infarction compared with men consuming <50 g per week. Similarly, dietary intake of n-3 fatty acids derived from seafood also was significantly associated with reduced mortality from myocardial infarction. Neither dietary seafood nor n-3 fatty acid intake was associated with a reduced risk of death from stroke or ischemic heart disease other than acute myocardial infarction. However, approximately a 20% reduction in total mortality associated with weekly fish/shellfish intake was observed in the study population (relative risk = 0.79, 95% confidence interval: 0.69, 0.91). These prospective data suggest that eating fish and shellfish weekly reduces the risk of fatal myocardial infarction in middle-aged and older men in Shanghai, China.

Analysis of Variance↗

PubMed2001

Gender- and smoking-related bladder cancer risk.

BACKGROUND: There is growing evidence that, when smoking habits are comparable, women incur a higher risk of lung cancer than men. Because smokers are also at risk for bladder cancer, we investigated possible sex differences in the susceptibility to bladder cancer among smokers. METHODS: A population-based, case--control study was conducted in Los Angeles, CA, involving 1514 case patients with bladder cancer and 1514 individually matched population control subjects. Information on tobacco use was collected through in-person interviews. Peripheral blood was collected from study participants to measure 3- and 4-aminobiphenyl (ABP)-hemoglobin adducts, a marker of arylamine exposure. Data were analyzed to determine whether the risk of bladder cancer differs between male and female smokers and whether female smokers exhibit higher levels of ABP-hemoglobin adducts than male smokers with comparable smoking habits. All statistical tests were two-sided. RESULTS: Cigarette smokers had a statistically significant 2.5-fold higher risk (95% confidence interval = 2.1 to 3.0) of bladder cancer than never smokers. Use of filtered versus nonfiltered cigarettes, low-tar versus higher tar cigarettes, or the pattern of inhalation did not modify the risk. The risk of bladder cancer in women who smoked was statistically significantly higher than that in men who smoked comparable numbers of cigarettes (P =.016 for sex-lifetime smoking interaction). Consistent with the sex difference in smoking-related bladder cancer risk, the slopes of the linear regression lines of the 3- and 4-ABP--hemoglobin adducts by cigarettes per day were statistically significantly steeper in women than in men (P values for sex differences <.001 and.006, respectively). CONCLUSION: The risk of bladder cancer may be higher in women than in men who smoked comparable amounts of cigarettes.

Adult↗

PubMed2001

Use of permanent hair dyes and bladder-cancer risk.

A population-based case-control study was conducted in Los Angeles, California, which involved 1,514 incident cases of bladder cancer and an equal number of age-, sex- and ethnicity-matched controls. Information on personal use of hair dyes was obtained from 897 cases and their matched controls. After adjustment for cigarette smoking, a major risk factor for bladder cancer, women who used permanent hair dyes at least once a month experienced a 2.1-fold risk of bladder cancer relative to non-users (p for trend = 0.04). Risk increased to 3.3 (95% CI = 1.3-8.4) among regular (at least monthly) users of 15 or more years. Occupational exposure to hair dyes was associated with an increased risk of bladder cancer in this study. Subjects who worked for 10 or more years as hairdressers or barbers experienced a 5-fold (95% CI = 1.3-19.2) increase in risk compared to individuals not exposed.

Adult↗

PubMed2001

Mechanical unfolding and refolding of proteins: an off-lattice model study.

Using an off-lattice model, we investigate the response of a protein molecule to external stretching and release. In particular we study the passive force in a protein as a function of the extension of the protein. These force-extension curves exhibit hysteresis loops, whose areas increase with the pulling rate and decrease with thermal noise. Most of these results seem to be appropriately described by a cusp catastrophe.

Biophysical Phenomena↗

PubMed2001

Genetic, dietary, and other lifestyle determinants of plasma homocysteine concentrations in middle-aged and older Chinese men and women in Singapore.

BACKGROUND: Epidemiologic studies have identified the plasma homocysteine concentration as a risk factor for atherothrombotic vascular disease. There is little information on the distributions and determinants of homocysteine concentrations in Asian populations. OBJECTIVE: The present study was designed to examine the relations between genetic and lifestyle factors and plasma homocysteine concentrations among Chinese in Singapore. DESIGN: Plasma total homocysteine, folate, vitamin B-12, and vitamin B-6 concentrations and genetic variation at the methylenetetrahydrofolate reductase (MTHFR) locus were measured in 486 Chinese men and women aged 45-74 y in Singapore. Data on dietary and other lifestyle factors were collected in face-to-face interviews. RESULTS: Men had higher plasma concentrations of total homocysteine than women (P = 0.0001). Age was positively associated with plasma homocysteine in both sexes (P for trend = 0.0001). Plasma concentrations of folate, vitamin B-12, and vitamin B-6 were inversely associated with homocysteine concentrations. Among individuals with low plasma folate, those possessing 2 copies of MTHFR mutant alleles had significantly higher homocysteine concentrations than did those with > or = 1 copy of the wild-type allele. Cigarette smoking, daily coffee consumption, and physical inactivity were positively related to plasma homocysteine concentrations in both sexes (P < 0.05). However, these associations disappeared after adjustment for plasma folate concentrations. CONCLUSIONS: Age, sex, plasma folate, vitamin B-12 and B-6 concentrations, and MTHFR genotype are independent determinants of plasma homocysteine in middle-aged and older Chinese in Singapore. These factors combined could account for up to 40% of the total variation in homocysteine concentrations in this Asian population.

Aged↗

PubMed2001

Prediagnostic levels of serum beta-cryptoxanthin and retinol predict smoking-related lung cancer risk in Shanghai, China.

Higher blood levels of beta-carotene have been found to be associated with reduced risk of lung cancer, but large intervention trials have failed to demonstrate reduced lung cancer incidence after prolonged high-dose beta-carotene supplementation. Data on blood levels of specific carotenoids other than beta-carotene in relation to lung cancer are scarce. Little is known about the relationship between prediagnostic serum levels of carotenoids, retinol, and tocopherols, and risk of lung cancer especially in non-Western populations. Between January 1986 and September 1989, 18,244 men ages 45-64 years participated in a prospective study of diet and cancer in Shanghai, China. Information on tobacco smoking and other lifestyle factors was obtained through in-person interviews. A serum sample was collected from each study participant at baseline. During the first 12 years of follow-up, 209 lung cancer cases, excluding those diagnosed within 2 years of enrollment, were identified. For each cancer case, three cancer-free control subjects were randomly selected from the cohort and matched to the index case by age (within 2 years), month and year of blood sample collection, and neighborhood of residence. Serum concentrations of retinol, alpha- and gamma-tocopherols, and specific carotenoids including alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin were determined on the 209 cases and 622 matched controls by high-performance liquid chromatography methods. A high prediagnostic serum level of beta-cryptoxanthin was significantly associated with reduced risk of lung cancer; relative to the lowest quartile, the smoking-adjusted relative risks (95% confidence intervals) for the 2nd, 3rd, and 4th quartile categories were 0.72 (0.41-1.26), 0.42 (0.21-0.84), and 0.45 (0.22-0.92), respectively (P for trend = 0.02). Increased serum levels of other specific carotenoids including alpha-carotene, beta-carotene, lycopene, and lutein/zeaxanthin were related to reduced risk of lung cancer although the inverse associations were no longer statistically significant after adjustment for smoking. A statistically significant 37% reduction in risk of lung cancer was noted in smokers with above versus below median level of total carotenoids. Serum retinol levels showed a threshold effect on lung cancer risk. Compared with the lowest quartile (<40 microg/dl), the smoking-adjusted relative risk (95% confidence interval) was 0.60 (0.39-0.92) for men in the 2nd-4th quartiles of retinol values combined; no additional decrease in risk was observed between individuals from the 2nd to 4th quartiles. There were no associations between prediagnostic serum levels of alpha- and gamma-tocopherols and lung cancer (all Ps for trend > or =0.4). The present data indicate that higher prediagnostic serum levels of total carotenoids and beta-cryptoxanthin were associated with lower smoking-related lung cancer risk in middle-aged and older men in Shanghai, China. Low level of serum retinol (with a threshold effect) is associated with increased lung cancer risk in this oriental population.

Aged↗

PubMed2001

Family history and risk of renal cell carcinoma.

Few analytical epidemiological studies have investigated family history (FH) of urinary tract cancers as a potential risk factor for renal cell carcinoma (RCC). A population-based case-control study involving 550 non-Asian RCC patients 25 to 74 years of age and an equal number of sex-, age-, and race-matched neighborhood controls was conducted in Los Angeles, California. Detailed information on FH of cancer, medical and medication histories, and other life-style factors was obtained through in-person interviews. Having a first-degree relative with kidney cancer was associated with a significantly increased risk of RCC [odds ratio (OR), 2.5; 95% confidence interval (CI), 1.04-5.9] after adjustment for potential confounding factors. Having a first and/or second-degree relative with kidney cancer was similarly associated with an increased risk of RCC (OR, 2.9; 95% CI, 1.4-6.3). Risk factors for RCC identified in the Los Angeles study include cigarette smoking, chronic obesity, history of hypertension, regular use of analgesics and amphetamines, intake of cruciferous vegetables (protective), and history of hysterectomy. None of the above risk factor-RCC associations differed significantly between RCC cases with and without a FH of kidney cancer. A FH of urinary tract cancers other than kidney cancer was not associated with RCC risk (OR, 0.7; 95% CI, 0.3-1.7). A FH of nonurinary tract cancers also was unrelated to RCC risk (OR, 1.1; 95% CI, 0.9-1.5).

Adult↗

PubMed2000

Prospective evaluation of infection with hepatitis G virus in relation to hepatocellular carcinoma in Shanghai, China.

The health consequences of hepatitis G virus (HGV) infection in humans remain to be determined. Inconsistent results of HGV and the risk of hepatocellular carcinoma (HCC) have been found in retrospective case-control studies. No prospective studies have addressed this issue. A prospective study including 18,244 men in Shanghai, China, was conducted to assess the role of HGV infection in HCC development. Serum HGV RNA and hepatitis B surface antigen (HBsAg) were assessed in 127 HCC case patients and 660 matched control subjects drawn from the cohort. Four patients with HCC (3.1%) and 21 control subjects (3.2%) were positive for serum HGV RNA. The presence of HGV RNA in prediagnostic serum was not associated with the risk of HCC (odds ratio, 1.0; 95% confidence interval, 0.3-2.9). No association between HGV RNA positivity and HCC risk was observed in either HBsAg-positive carriers or noncarriers. It is concluded that HGV infection plays no role in HCC development in this high-risk population.

Aged↗

PubMed2000

Isothiocyanates, glutathione S-transferase M1 and T1 polymorphisms, and lung-cancer risk: a prospective study of men in Shanghai, China.

BACKGROUND: Dietary isothiocyanates inhibit lung carcinogenesis in laboratory animals but human data are limited. Glutathione S-transferases M1 and T1 (GSTM1 and GSTT1) conjugate isothiocyanates leading to more rapid elimination. Common deletion polymorphisms of GSTM1 and GSTT1 abolish enzyme activity. We hypothesised that chemopreventive effects of isothiocyanates might be heightened when enzymes that enhance their elimination are lacking. METHODS: We examined the relation between total isothiocyanate concentrations in urine, collected before diagnosis, and the subsequent risk of lung cancer among 232 incident cases of lung cancer and 710 matched controls from a cohort of 18,244 men in Shanghai, China, followed from 1986 to 1997. Homozygous deletion of the GSTM1 and GSTT1 genes were determined by PCR. FINDINGS: Individuals with detectable isothiocyanates in the urine were at decreased risk of lung cancer (smoking-adjusted relative risk for lung cancer=0.65 [95% CI 0.43-0.97]). This protective effect of isothiocyanates was seen primarily among individuals with homozygous deletion of GSTM1 (0.36 [0.20-0.63]) and particularly with deletion of both GSTM1 and GSTT1 (0.28 [0.13-0.57]). INTERPRETATION: Isothiocyanates appeared to reduce lung-cancer risk in this cohort of Chinese men. Reduction in risk was strongest among persons genetically deficient in enzymes that rapidly eliminate these chemopreventive compounds.

Case-Control Studies↗

PubMed2000

Preserved foods in relation to risk of nasopharyngeal carcinoma in Shanghai, China.

A population-based case-control study was conducted in Shanghai, China, to investigate the association between dietary factors and risk of nasopharyngeal carcinoma (NPC). The study included 935 NPC patients aged 15 to 74 years and 1,032 community controls. Exposures to salted fish and other protein-containing preserved food were associated with increased risk of NPC. Individuals who ate salted fish at least once a week had an 80% increase in risk of NPC relative to those who ate salted fish less than once a month (p = 0.07). Compared with those in the lowest quartile of protein-containing preserved foods, subjects in the highest quartile of intake experienced a statistically significant 78% increase in risk of NPC [odds ratio (OR) = 1.78, 95% confidence interval (CI) = 1.37-2.31], with a dose-dependent relationship (p for linear trend < 0.001 ). A similar association between intake of preserved vegetables and NPC risk was observed (OR = 1.39, p for linear trend = 0.003). In contrast, high intake of oranges/tangerines was associated with a statistically significant reduction in risk of NPC (OR = 0.55, p for linear trend < 0.001). When we examined the joint effect of preserved food and oranges/tangerines on risk of NPC, subjects in the highest tertile of preserved food and the lowest tertile of orange/ tangerine intake had a 3-fold increase in risk (95% CI = 2.08-4.91) compared with those in the lowest tertile of preserved food and the highest tertile of orange/tangerine intake.

Adolescent↗

PubMed2000

Non-dietary risk factors for nasopharyngeal carcinoma in Shanghai, China.

A population-based case-control study was conducted in Shanghai, China, to investigate the associations between exposures to various non-dietary variables and risk of nasopharyngeal carcinoma (NPC). A total of 935 NPC patients and 1,032 community controls were included. Active cigarette smoking was a moderate risk factor for NPC [odds ratio (OR) = 1.28, 95% confidence interval (CI) 1.02-1.61]. Results were highly consistent between men and women. It is estimated that 12% of NPC cases in Shanghai, China, can be attributable to cigarette smoking. Among lifelong nonsmokers, there was a strong and statistically significant positive association between NPC risk and exposure to substantial secondhand smoke as a child or as an adult in women. However, the associations among lifelong nonsmoking men were weaker and not statistically significant. The gender differences in risk associated with passive smoking were either statistically significant or almost so. There were excess numbers of NPC patients compared with control subjects who had a history of chronic ear and nose disease (OR = 1.96, 95% CI 1.56-2.46) and a family history of NPC (OR = 7.47, 95% CI 2.14-12.88).

Adolescent↗

PubMed2000

Decreased luteinizing hormone receptor mRNA expression in human ovarian epithelial cancer.

OBJECTIVES: The objective of this study was to examine the distribution and cellular localization of luteinizing hormone receptor (LHR) in ovarian epithelial tumors (OETs) and their presumed precursor lesions-ovarian epithelial inclusions (OEIs). The clinicopathologic correlation of the receptor expression in OET was also examined. METHODS: Fifteen microdissected samples of ovarian surface epithelium (OSE), 20 OEIs from benign ovaries, and 141 OETs, including 48 cystadenomas, 33 borderline tumors, 60 carcinomas, and 5 metastatic cancers, were examined for LHR expression by using reverse transcription polymerase chain reaction and in situ hybridization. LHR expression in tumor epithelium and tumor stroma was analyzed separately. The clinicopathologic correlation data were analyzed by standard analysis of variance and contingency table methods. RESULTS: LHR expression was identified in the majority of OSE and OEI samples. In OETs, LHR positivity was found in the epithelial cells in 27% of cases and in the stromal compartment in 37% of cases. LHR-positive stromal cells were mainly luteinized cells. Within the tumor epithelium, LHR expression was detected in 42% of benign, 24% of borderline, and 17% of malignant OETs. LHR expression in tumor stroma showed a similar trend of reduction from benign to malignant OETs. Within the 17 carcinomas, LHR was expressed in the epithelium in 47% of grade 1, 12% of grade 2, and only 5% of grade 3 cancers. The mean age of the LHR-positive group was younger than that of the receptor-negative patients. Compared with mucinous and other types of OETs, serous OETs showed higher LHR expression in the epithelium. Compared with the OETs removed in the different menstrual phases, OETs in the secretory phase showed higher LHR in the tumor stroma than in the proliferative phase. No receptor mRNA was detected in the epithelium of five carcinomas metastatic to the ovary. LHR transcription splicing variants from a single previous report were confirmed in this study. CONCLUSIONS: Malignant OETs have significant reduction of LHR expression compared with precursor lesions and benign and borderline OETs. LHR expression shows a steady decline from low-grade to high-grade ovarian cancer. The presence of LHR receptor in tumor epithelium suggests that luteinizing hormone in serum may have direct influence on tumor growth, whereas the receptor in tumor stroma may be indicative of a paracrine function of LH in the development of OETs.

Adolescent↗

PubMed2000

Non-steroidal anti-inflammatory drugs and bladder cancer prevention.

Inclusion of phenacetin among 'proven' human carcinogens by the IARC in 1987, raised concerns about the carcinogenic potential of acetaminophen, its major metabolite. Acetaminophen has been implicated as a possible causal agent in the development of cancer of the renal pelvis. The bladder and renal pelvis, which derive from the same embryological structure, share the same transitional type of epithelium. Past studies have been inconclusive on the possible relationship among these analgesics and bladder cancer but no large, highly detailed study of this association has been conducted. A population-based case-control study conducted in Los Angeles, California, involved 1514 incident bladder cancer cases and an equal number of controls who were matched to the index cases by sex, date of birth (within 5 years) and race. Detailed information on medication use and prior medical conditions was collected through in-person interviews. Regular use of analgesics was not associated with an increased risk of bladder cancer in either men or women. In fact, compared with non- or irregular users, regular analgesic users were at a decreased risk of bladder cancer overall (odds ratio (OR) = 0.81, 95% confidence interval (CI) = 0.68-0.96). However, there were clear differences in both the direction and strength of the associations between the different formulation classes of analgesics and bladder cancer risk. Intake of phenacetin was positively related to bladder cancer risk in a dose-dependent manner while intake of its major metabolite in humans, acetaminophen, was unrelated to risk. Intake of all classes of NSAIDs, except pyrazolon derivatives, were negatively associated with bladder cancer risk, with suggestive evidence that the protective effect varies in strength by subcategories of formulation. Acetic acids seemed to exhibit the strongest protective effect, whereas aspirin/other salicylic acids and oxicam showed the weakest protection.

Adult↗