Betel quid chewing, cigarette smoking and alcohol consumption related to oral cancer in Taiwan

A hospital-based case-control study of matched pairs was conducted to explore (a) the relationship between the use of betel quid chewing, cigarette smoking, alcohol drinking and oral cancer and (b) synergism between these factors. The case group consisted of 104 male and 3 female oral cancer patients and these were compared with 194 male and 6 female matched controls. We found by univariate analysis that alcohol consumption, smoking, betel quid chewing, educational level and occupation were associated with oral cancer. The adjusted odds ratios were to be found elevated in patients who were smoking and betel quid chewing. After adjusting for education and occupation covariates, the incidence of oral cancer was computed to be 123-fold higher in patients who smoked, drank alcohol and chewed betel quid than in abstainers. The synergistic effects of alcohol, tobacco smoke and betel quid in oral cancer were clearly demonstrated, but there was a statistically significant association between oral cancer and betel quid chewing alone. Swallowing betel quid juice (saliva extract of betel quid produced by chewing) or including unripened betel fruit in the quid both seemed to enhance the risks of contracting oral cancer.

Prevalence of betel quid chewing habit in Taiwan and related sociodemographic factors

The prevalence of betel quid chewing habit in Taiwan was surveyed in a group of Chinese people from Kaohsiung city and in a second group from the aboriginal inhabitants of South Taiwan. In all 1299 participants constituted Group 1 (85.2% response rate) and 827 Group 2 (70.1% response rate). People were interviewed in their homes in house-to-house survey, according to a structured questionnaire developed and evaluated by the authors. Of the Kaohsiung inhabitants covering all ages and both sexes, 6% was a current betel chewer and 4% was an ex-chewer, whereas 42% of the aborigines aged over 15 yr was a current chewer and 1% an ex-chewer. Lifetime prevalence was 10%. Betel chewing enjoys islandwide popularity among the 20 million inhabitants of Taiwan; the number of current and ex-users was estimated at 2.0 million (95% CI 1.6-2.4 million). The betel quid was prepared in two different ways. In one, used mainly by aborigines, fresh areca nut was simply wrapped with betel leaf and in another, popular mainly among Chinese, a lengthwise piece of betel fruit and lime paste was sandwiched between two halves of an areca nut. A high proportion of chewers was also a smoker and drinker, but tobacco was not found to be chewed together with betel quid. Consumption varied between 14 to 23 portions per day, with individual frequencies ranging widely from 1 to over 200 portions a day. A statistical analysis of sociodemographic factors showed that lesser educated older men, blue collar workers, smokers and drinkers were the likeliest betel chewers.

Risk factors for primary lung cancer among non-smoking women in Taiwan

BACKGROUND

Although cigarette smoking is considered to be the most important cause of lung cancer, smoking behaviour cannot fully explain the epidemiological characteristics of lung cancer in Taiwanese women, who rarely smoke but contract lung cancer relatively often. There are other causes of lung cancer that have produced variability in lung cancer incidence.

METHODS

A case-control study involving interviews with 117 female patients (including 106 non-smoking) suffering from lung cancer and the same number of individually matched hospital controls was conducted in Kaohsiung, Taiwan between 1992 and 1993. The questionnaire administered to cases and controls collected information on cigarette smoking and suspected risk factors for lung cancer. Multivariate logistic regression analysis was applied to assess smoking for all women and suspected risk factors for non-smoking women.

RESULTS

The relationship between cigarette smoking and lung cancer was statistically significant although only a small proportion (9.4%) of female patients had smoked. However, the risk of contracting cancer for non-smoking women appears to be associated with certain cooking practices, especially preparing meals in kitchens not equipped with a fume extractor at cooking age of 20-40 years (odds ratio [OR] = 8.3; 95% confidence interval [CI]: 3.1-22.7. These factors and a history of pulmonary tuberculosis plus low consumption of fresh vegetables explained 78% of the summary attributable risks for non-smoking women in a multivariate logistic regression model.

CONCLUSIONS

Exposure to fumes from cooking oils, when not reduced by an extractor, may be an important factor in causing lung cancer in non-smoking Taiwanese women.

Prevalence of shoulder and upper-limb disorders among workers in the fish-processing industry

A cross-sectional study was conducted among fish-processing workers to evaluate the prevalence of shoulder and upper-limb discomforts and to assess the associated ergonomic risk factors. A prestructured interview, a medical check-up, and job analyses were performed to determine musculoskeletal disorders among 207 workers in eight factories. The results showed shoulder girdle pain (30.9%), epicondylitis (14.5%), and carpal tunnel syndrome (15.0%) as the three most common soft-tissue disorders. The odds ratio of shoulder girdle pain was 1.6 (95% CI 1.1-2.5) among the workers who performed tasks with repetitive movement of their upper limbs, while it was 1.8 (95% CI 1.2-2.5) for the workers who sustained forceful movement of their upper limbs during work. Women taking oral contraceptives had a 2.0 times higher odds ratio for carpal tunnel syndrome than did other women. It would appear that untrained or unskilled workers were prone to suffer from musculoskeletal disorders.

Chinese food cooking and lung cancer in women nonsmokers

Cigarette smoking cannot fully explain the epidemiologic characteristics of lung cancer in Taiwanese women, who smoke rarely but have lung cancer relatively often. In a previous study, the authors suspected that exposure to fumes from cooking oils was an important risk factor for lung cancer in Taiwanese women nonsmokers in the Republic of China. In a new case-control study conducted in 1993-1996, they further explored the association of oil fumes with lung cancer in women. Two sets of controls were used concurrently. The subjects were 131 nonsmoking incident cases with newly diagnosed and histologically confirmed primary carcinoma of the lung, 252 hospital controls hospitalized for causes unrelated to diseases of smoking, and 262 community controls; all controls were women nonsmokers matched by age and date of interview. Details on cooking conditions and habits were collected, in addition to other epidemiologic data. Lung cancer risk increased with the number of meals per day to about threefold for women who cooked these meals each day. The risk was also greater if women usually waited until fumes were emitted from the cooking oil before they began cooking (adjusted odds ratios = 2.0-2.6) and if they did not use a fume extractor (adjusted odds ratios = 3.2-12.2). These results suggest that a proportion of lung cancer may be attributable to the habit of waiting until the cooking oil has been heated to a high temperature before cooking the food.

Endoscopic pituitary surgery: an early experience

BACKGROUND

As an element of a minimally invasive management approach, we had developed an endonasal endoscopic transsphenoidal technique for the treatment of pituitary tumors. Initially, four patients were operated on via a sublabial, transseptal approach using a fiberoptic rigid endoscope in conjunction with the operating microscope. Encouraged by that experience, our subsequent 11 patients had undergone endonasal endoscopic transsphenoidal surgery without the use of a retractor or speculum.

METHODS

Our group of patients included nine females and six males, with an age range of 17-88 years (median: 43 years). There were four microadenomas, four intrasellar macroadenomas, three macroadenomas with suprasellar extension, three invasive macroadenomas involving the cavernous sinus with suprasellar extension, and one metastatic adenocarcinoma.

RESULTS

Thirteen patients with pituitary adenomas experienced resolution of their symptoms postoperatively. One patient with a recurrent prolactinoma responded partially following surgery and subsequently underwent gamma knife radiosurgery. Two patients were treated with postoperative fractionated radiation therapy, one for residual pituitary adenoma in the cavernous sinus, and the other for metastatic adenocarcinoma, respectively. The first patient, treated via an endonasal endoscopic approach for biopsy of the metastatic adenocarcinoma, developed postoperative cerebrospinal fluid (CSF) leak that was successfully managed with endoscopic packing of a fat graft.

CONCLUSIONS

The endonasal endoscopic transsphenoidal approach facilitates faster postoperative recovery by the avoidance of traditional incision and postoperative nasal packing. It offers a panoramic view of the sphenoid sinus and excellent visualization of the sellar and suprasellar structures with increased illumination and magnification. Such visualization provides the potential for more complete tumor resection, as well as a better chance of preserving pituitary function and avoiding neurovascular injury.

A method for the rapid construction of cRNA standard curves in quantitative real-time reverse transcription polymerase chain reaction

Quantification of nucleic acids, especially of mRNA, is increasingly important in biomedical research. The recently developed quantitative real-time polymerase chain reaction (PCR) - a highly sensitive technology for the rapid, accurate and reproducible quantification of gene expression - offers major advantages over conventional quantitative PCR. Transcript quantification is performed in the exponential phase of the PCR reaction through extrapolation of fluorescence signals from a standard calibration curve which represents the initial copy number for a given fluorescence signal. We have developed a method for gene transcript quantification which is based on a LightCycler - assisted real-time PCR in combination with a simple and rapid approach for the construction of external cRNA standards with identical gene sequences as the target gene. Synthesis of cRNAs was performed by in vitro transcription with T7 RNA polymerase followed by reverse transcription and real-time PCR. We applied this approach for transcript quantification of eukaryotic initiation factor 3 p110 (EIF3S8) mRNA in normal testicular tissue. We also present a rapid and simple strategy for the construction of cRNA standards for use in real-time PCR.

Mortality for certain diseases in areas with high levels of arsenic in drinking water

Blackfoot disease was prevalent in a limited area on the southwest coast of Taiwan, where artesian well water containing arsenic (median = 0.78 ppm arsenic) had been used for many years. Previous studies of arsenic exposure in the blackfoot disease endemic area have been focused on malignant tumors. We, therefore, conducted this study to analyze mortality of all death causes in blackfoot disease endemic areas and to determine other neglected cancers or noncancer diseases related to artesian well water containing high levels of arsenic. We calculated standardized mortality ratios for cancer and noncancer diseases, by sex, during the period from 1971 to 1994 and compared them to the local reference group (i.e, Chiayi-Tainan County) and the national reference group (i.e., Taiwan population). The results revealed marked standardized mortality ratio differences for the 2 reference groups. Greater mortality was found for males and females with bladder, kidney, skin, lung, nasal-cavity, bone, liver, larynx, colon, and stomach cancers, as well as lymphoma than in the local reference population. With respect to noncancer diseases, we found greater mortality for males and females who had vascular disease, ischemic heart disease, diabetes mellitus, and bronchitis than in the local reference group. Mortalities for other diseases--including rectal cancer, cerebrovascular disease, and other diseases--were higher among cases than the local reference group. Our results indicated that the hazardous effect of arsenic is systemic. Diseases related to arsenic exposure included those reported previously by other investigators, as well as diseases reported in the present study.

The gap-junctional protein connexin40 is elevated in patients susceptible to postoperative atrial fibrillation

BACKGROUND

Atrial fibrillation (AF), a cardiac arrhythmia arising from atrial re-entrant circuits, is a common complication after cardiac surgery, but the proarrhythmic substrate underlying the development of postoperative AF remains unclear. This study investigated the hypothesis that altered expression of connexins, the component proteins of gap junctions, is a determinant of a predisposition to AF.

METHODS AND RESULTS

The expression of the 3 atrial connexins-connexins 43, 40, and 45-was analyzed at the mRNA and protein levels by Northern and Western blotting techniques and immunoconfocal microscopy in right atrial appendages from patients with ischemic heart disease who were undergoing coronary artery bypass surgery. Twenty percent of the patients subsequently developed AF, which allowed retrospective division of the samples into 2 groups, non-AF and AF. Connexin43 and connexin45 transcript and protein levels did not differ between the groups. However, connexin40 transcript and protein were expressed at significantly higher levels in the AF group. Connexin40 protein was markedly heterogeneous in distribution.

CONCLUSIONS

Atrial myocardium susceptible to AF is distinguished from its nonsusceptible counterpart by elevated connexin40 expression. The heterogeneity of connexin distribution could give rise to different resistive properties and conduction velocities in spatially adjacent regions of tissue, which become enhanced and, hence, proarrhythmic the higher the overall level of connexin40.

Elevated interleukin-8 levels in the urine of patients with urinary tract infections

Pyuria is one of the main features of urinary tract infections (UTI). Nevertheless, the mechanism of polymorphonuclear leukocyte (PMN) recruitment into the urine remains to be investigated. We examined whether interleukin-8 (IL-8), a potent neutrophil chemoattractant and activator, was involved in pyuria seen in UTI. Of 113 patients, 112 had elevated levels of IL-8 in their urine (1,078.0 +/- 181.5 pg/ml), regardless of whether they had an upper or lower UTI; this was in contrast to undetectable levels (less than 16 pg/ml) in the urine of all of the 20 normal individuals and 74 control patients without UTI. A concomitant study revealed increases in urine IL-6, but not IL-1 beta, and tumor necrosis factor alpha levels in patients with UTI. In addition to gram-negative bacteria, a wide spectrum of microorganisms was capable of inducing IL-8 production in urine. Local production of IL-8 in the urinary tract was suggested by a urine IL-8 level that was higher than the paired serum IL-8 level. The urine IL-8 level correlated with the number of PMN in the urine, and an average of half of the chemotactic activity in urine from patients with UTI could be abrogated by anti-IL-8 antibody treatment in vitro. Furthermore, urine IL-8 purified from patients was bioactive and showed multiple forms on immunoblotting analysis. This is the first documentation of IL-8 in the urine of patients with UTI, and these results imply that IL-8 is involved in inducing PMN migration into the urinary tract.

Climate, traffic-related air pollutants, and asthma prevalence in middle-school children in taiwan

This study compared the prevalence of asthma with climate and air pollutant data to determine the relationship between asthma prevalence and these factors. We conducted a nationwide survey of respiratory illness and symptoms in middle-school students in Taiwan. Lifetime prevalences of physician-diagnosed asthma and of typical symptoms of asthma were compared to air monitoring station data for temperature, relative humidity, sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, and particulate matter with aerodynamic diameter [less than/equal to] 10 microm (PM(10)). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Asthma prevalence rates adjusted for age, history of atopic eczema, and parental education were associated with nonsummer (June-August) temperature, winter (January-March) humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, for both girls and boys. Nonsummer temperature, winter humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, were positively associated with the prevalence of asthma in middle-school students in Taiwan.

Curcumin inhibits SK-Hep-1 hepatocellular carcinoma cell invasion in vitro and suppresses matrix metalloproteinase-9 secretion

Curcumin (diferuloylmethane), widely used as a spice and coloring agent in food, possesses potent antioxidant, anti-inflammatory and anticarcinogenic properties. Recently, curcumin was further demonstrated to have an antimetastatic effect in mice. In this study, we attempted to clarify the possible mechanisms of this latter effect of curcumin. A highly invasive SK-Hep-1 cell line of human hepatocellular carcinoma (HCC) was selected for this study. An in vitro assay, without or with Matrigel matrix, was used to quantitate cellular migration and invasion. Gelatin-based zymography was adapted to assay the secretion of matrix metalloproteinase (MMP). We found that curcumin, at 10 microM, inhibited 17.4 and 70.6% of cellular migration and invasion of SK-Hep-1, respectively. Compared with a less invasive human HCC cell line, Huh-7, SK-Hep-1 showed a much higher MMP-9 secretion. Further, and parallel with its anti-invasion activity, curcumin inhibited MMP-9 secretion in SK-Hep-1 in a dose-dependent fashion. We conclude that curcumin has a significant anti-invasion activity in SK-Hep-1 cells, and that this effect is associated with its inhibitory action on MMP-9 secretion.

Thromboxane A2 and vascular smooth muscle cell proliferation

In the present study we describe the intracellular pathways for the transmission of growth signals by the potent vasoconstricting eicosanoids prostaglandin H2 and thromboxane A2 in smooth muscle cells from rat aorta. Carbocyclic thromboxane A2 and U46619 are stable thromboxane A2 mimetics acting at the common thromboxane A2/prostaglandin H2 receptor. Carbocyclic thromboxane A2 (10(-6) mol/L) induced an approximately 2.5-fold increase in [Ca2+]i above the basal value at 25 seconds. Maximal stimulation of the 42-kD mitogen-activated protein kinase isoform by both thromboxane A2 mimetics occurred at 5 minutes. Both thromboxane A2 mimetics at a concentration of 10(-6) mol/L induced the expression of c-fos and early growth response gene-1 (egr-1) mRNA, with a maximum at 30 minutes. Carbocyclic thromboxane A2 (10(-6) mol/L) induced a 3.3-fold increase in [3H]thymidine incorporation into cell DNA above the basal value and produced a 3.5-fold elevation of platelet-derived growth factor-BB-dependent [3H]thymidine incorporation into cell DNA. Similar effects of U46619 (10(-6) to 10(-5) mol/L) alone did in combination with platelet-derived growth factor-BB on cell DNA synthesis were obtained. The thromboxane A2/prostaglandin H2 receptor antagonist SQ29548 (10(-6) mol/L) completely suppressed the mitogenic effect of both thromboxane A2 mimetics (10(-6) mol/L). Pertussis toxin (10 to 100 ng/mL) did not influence the mitogenic effects of the thromboxane A2 mimetics. Carbocyclic thromboxane A2 (10(-6) mol/L) and platelet-derived growth factor-BB (20 ng/mL) per ser caused a 44% and 100% increase in cell number, respectively. In the presence of carbocyclic thromboxane A2 (10(-6) mol/L), platelet-derived growth factor-BB induced a 152% increase in cell number. Similar results were obtained with U46619 alone or in combination with platelet-derived growth factor-BB.

Tattooing as a risk of hepatitis C virus infection

The association of hepatitis C virus (HCV) infection and tattooing was studied in 87 tattooed and 126 tattoo free healthy young men who did not engage in intravenous drug use or multiple sexual activity. Antibody against HCV (anti-HCV) was tested in serum specimens by enzyme immunoassay with C100-3, NS3, and core antigens; 11 of the 87 (12.6%) tattooed and 3 of the 126 (2.4%) tattoo free subjects were positive for anti-HCV (odds ratio = 5.9, 95% CI = 1.6-22.0). A relationship was demonstrated by an increased risk for HCV infection with an increasing number of tattooed site (P(trend) = 0.002). All but one of the 87 tattooed subjects had been infected by hepatitis B virus (HBV) and 25 were carriers of hepatitis B surface antigen (HBsAg). None of the 25 HBsAg carriers was positive for anti-HCV whereas 11 of the 62 HBsAg non-carriers had anti-HCV, suggesting a negative association between the HBsAg carriage and the long lasting anti-HCV (P = 0.02, Fisher's exact). The status of the tattooer was also an important determinant for HCV infection; the risk was higher if tattooing was done by a non-professional friend than by a professional tattooist. Tattooing, probably with improperly sterilized needles, can clearly pose an increased risk for HCV infection in Taiwan. This study indicates the need for legal standards for hygienic tattooing as part of preventive measures for the control of parenterally transmitted infections.

Is asymptomatic hemorrhagic transformation really innocuous?

OBJECTIVES

Asymptomatic hemorrhagic transformation (HT) is not associated with immediate deterioration of patients with acute ischemic stroke. However, it is unclear whether it is clinically innocuous with respect to long-term outcome. The aim of this study was to determine the impact of asymptomatic HT on 3-month outcome.

METHODS

A consecutive series of 1,618 patients, hospitalized between January 2004 and August 2007 for ischemic stroke within 7 days from symptom onset were identified in a prospective stroke registry database. Those who had no evidence of acute cerebral ischemia on diffusion-weighted MRI, who did not undergo T2-weighted gradient echo MRI, whose modified Rankin Scale (mRS) score at 3 months after stroke onset was not available, or who had symptomatic HT were excluded. The odds ratio (OR) of asymptomatic HT was calculated for the full distribution of mRS score and adjusted for variables with p < 0.25 with respect to their associations with asymptomatic HT or functional outcome.

RESULTS

Of 1,412 patients eligible for the study, 100 (7.1%) had asymptomatic HT. Patients who experienced asymptomatic HT were more likely to have cardioembolic stroke, to receive thrombolytic therapy, to receive anticoagulation with heparin, and to have a higher initial NIH Stroke Scale score. The crude and adjusted ORs of asymptomatic HT for an increment of mRS score at 3 months were 2.94 (95% confidence interval 2.05-4.24) and 1.90 (1.27-2.82), respectively.

CONCLUSIONS

Our study shows that the odds of a worse outcome are increased by a factor of 2 in patients with asymptomatic HT compared with those without HT after acute ischemic stroke.

Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan

The prevalence of allergic rhinitis, a common respiratory disorder, may be rapidly increasing. Epidemiological studies, however, indicate little about its association with climatic factors and air pollution. The relationship between traffic-related air pollutants and allergic rhinitis in middle-school students was therefore investigated. In a nationwide survey of middle-school students in Taiwan conducted in 1995/1996, the lifetime prevalence of physician-diagnosed allergic rhinitis and typical symptoms of allergic rhinitis were compared with air-monitoring station data on temperature, relative humidity, sulphur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), carbon monoxide (CO) and particulate matter with a 50% cut-off aerodynamic diameter of 10 microm (PM10). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Mean (range) annual exposures were: CO 853 (381-1,610) parts per billion (ppb), NOx 35.1 (10.2-72.4) ppb, SO2 7.57 (0.88-21.2) ppb, PM10 69.2 (40.1-116.2) microg x m(-3), O3 21.3 (12.4-34.1) ppb, temperature 22.9 (19.6-25.1) degrees C, and relative humidity 76.2 (64.8-86.2)%. The prevalence of physician-diagnosed allergic rhinitis was 28.6 and 19.5% in males and females, respectively, with prevalence of questionnaire-determined allergic rhinitis 42.4 and 34.0%. After adjustment for age, parental education and history of atopic eczema, physician-diagnosed allergic rhinitis was found to be associated with higher nonsummer (September-May) warmth and traffic-related air pollutants, including CO, NOx and O3. Questionnaire-determined allergic rhinitis correlated only with traffic-related air pollutants. Nonsummer warmth and traffic-related air pollution, probably mediated through exposure to common allergens such as dust mites, are possible risk factors for allergic rhinitis in middle-school-aged children.

Protection against lethal bacterial infection in mice by monocyte-chemotactic and -activating factor

Chemotactic factors regulate the recruitment of neutrophils, lymphocytes, or monocytes-macrophages to infectious and inflammatory sites. The purpose of this study was to determine whether monocyte-chemotactic and -activating factor (MCAF [MCP-1], a JE gene product) also influences the host defense mechanism against microbial infection. We evaluated the effect of recombinant human MCAF on the survival rate of mice systemically infected with Pseudomonas aeruginosa or Salmonella typhimurium. The administration of 2.5 micrograms of MCAF 6 h before infection completely protected the mice from lethal infection. Mice with cyclophosphamide-induced leukopenia exhibiting increased susceptibility to P. aeruginosa were also endowed with resistance by the same dose of MCAF. Administration of MCAF at -6 h was critical, since MCAF given either earlier or later than -6 h failed to rescue mice from lethal infection. The in vivo effect on the survival of mice paralleled the reduced recovery of viable P. aeruginosa or S. typhimurium from the peritoneal cavity, i.e., the number of recovered bacteria from the MCAF (2.5 micrograms per mouse)-treated mice was reduced to less than 2% of control mice for P. aeruginosa and 4% of control mice for S. typhimurium at 24 h. Since MCAF exhibited chemotaxis on murine macrophages as well as enhanced phagocytosis and killing of bacteria in vitro, the activation of macrophages, followed by the recruitment into the peritoneal cavity, is responsible for eliminating bacteria and thus enhancing the survival rate.

Isolation and characterization of human mesenchymal stem cells from gingival connective tissue

BACKGROUND AND OBJECTIVE

The main purpose of this study was to isolate and characterize gingival connective tissue-derived mesenchymal stem cells (GMSCs). The secondary purpose was to present a modified isolation method for the GMSCs.

MATERIAL AND METHODS

Collected healthy gingival tissue samples were de-epithelialized and minced into small fragments. The tissues were digested by dispase and collagenase IV for 30 min. The first digested cell suspension was discarded, and then additional digestion was performed to the remaining cells in the same solution for 90 min. The isolated cells from gingiva was incubated in 37°C humidified condition and observed by inverted microscope. Cytoskeletal morphology was evaluated by phalloidin immunofluorescence. Potency of the cells was tested by colony-forming unit fibroblast assay. GMSCs were characterized by osteogenic, adipogenic and chondrogenic differentiation, and flow cytometric, immunofluorescence analysis.

RESULTS

GMSCs showed spindle-shaped, fibroblast-like morphology, colony-forming abilities, adherence to plastic and multilineage differentiation (osteogenic, adipogenic, chondrogenic) potency. GMSCs expressed CD44, CD73, CD90 and CD105, but did not express CD14, CD45, CD34 and CD19 in flow cytometry. Expression of stem cell markers (SSEA-4, STRO-1, CD146, CD166 and CD271) and a mesenchymal marker (vimentin) were observed by immunofluorescence.

CONCLUSIONS

In conclusion, we isolated and characterized stem cells from human gingival connective tissue with modified protocol. GMSCs showed multipotency with high proliferation and characteristics of mesenchymal stem cells. GMSCs are promising sources for tissue engineering and may be obtained during routine procedures under local anesthesia. Further research is needed to evaluate the potential of GSMCs' proliferation and cryopreservation.

A sensitive enzyme-linked immunosorbent assay for human interleukin-8

In order to quantify human interleukin-8 (IL-8), which is chemotactic for T cells and basophils as well as neutrophils, we developed an enzyme-linked immunosorbent assay (ELISA). Since binding inhibition tests indicated that three monoclonal antibodies (mAbs; BS-1, WS-4, WS-6) blocked the binding of 125I-labelled IL-8 to neutrophils, we tested an ELISA using these mAbs as primary antibodies, rabbit anti-IL-8 Ab as the secondary antibody, and alkaline phosphatase-labelled goat anti-rabbit Ab as the conjugate. Among the three mAbs tested, WS-4 was the most sensitive with a detection limit of 16 pg/ml. Several other cytokines, including monocyte chemotactic and activating factor (MCAF), which is structurally related to IL-8, showed no cross-reactivity in this system, indicating that this ELISA is specific for IL-8. The coefficients of variation for the intra- and interassays were below 10%. Furthermore, this ELISA also detected natural IL-8 (including both 72 and 77 amino acid forms) produced by cultured human cells and cell lines stimulated with IL-1, suggesting that this system will be useful in the detection of natural IL-8 in various body fluids.

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC)-mediated generation of reactive oxygen species causes cell cycle arrest and induces apoptosis via activation of caspase-3, mitochondria dysfunction and nitric oxide (NO) in human osteogenic sarcoma U-2 OS cells

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC), a member of the isothiocyanate family, have been shown to exhibit antineoplastic ability against many human cancer cells. In this study, we found that exposure of human osteogenic sarcoma U-2 OS cells to BITC and PEITC led to induce morphological changes and to decrease the percentage of viable cells in a time- and dose-dependent manner. BITC and PEITC induced cell cycle arrest at G2/M phase at 48 h treatment and inhibited the levels of cell cycle regulatory proteins such as cyclin A and B1 in U-2 OS cells but promoted the level of Chk1 and p53 that led to G2/M arrest. BITC and PEITC induced a marked increase in apoptosis (DNA fragmentation) and poly(ADP-ribose)polymerase (PARP) cleavage, which was associated with mitochondrial dysfunction and the activation of caspase-9 and -3. BITC and PEITC also promoted the ROS production in U-2 OS cells and the N-acetylcysteine (NAC, an antoxidant agent) was pretreated and then treated with both compounds which led to decrease the levels of ROS and increase the cell viability. Interestingly, BITC and PEITC promoted the levels of NO production and increased the iNOS enzyme. Confocal laser microscope also demonstrated that BITC and PEITC promoted the release of cytochrome c and AIF, suggesting that both compounds induced apoptosis through ROS, caspase-3 and mitochondrial, and NO signaling pathways. Taken together, these molecular alterations and signaling pathways offer an insight into BITC and PEITC-caused growth inhibition, G2/M arrest, and apoptotic death of U-2 OS cells.

Demonstration of two distinct subsets of gastric varices. Observations during a seven-year study of endoscopic sclerotherapy

Over a seven-year period, assessment of gastric varices was made on 225 patients receiving endoscopic sclerotherapy for variceal hemorrhage. Of 170 patients with complete data, gastric varices were observed in 26 (15.3%). Importantly, two distinct subsets of gastric varices were identified: varices distal to the gastroesophageal junction without extension into the fundus, termed "junctional varices," occurred in 11.2%, and varices that were confined only to the fundus, termed "fundal varices," occurred less frequently in 4.1%. Although rebleeding was increased in both subsets of gastric varices, junctional varices were more amenable to sclerotherapy. Patients with fundal varices (N = 7) had a significantly higher rebleeding rate, increased complications with sclerotherapy, and significantly decreased survival (P less than 0.005) when compared to patients with esophageal varices alone (N = 87) who were followed for more than three months. Cumulative survival was not significantly different (P less than 0.08) in patients with junctional varices (N = 19) when compared with patients with esophageal varices alone. We conclude that not all patients with gastric varices have a poor result with sclerotherapy. Recognition of these subsets may improve treatment strategies in patients with gastric varices.

Interaction between cigarette, alcohol and betel nut use on esophageal cancer risk in Taiwan

OBJECTIVE

In 2003 esophageal cancer was the sixth leading cause of death among men in Taiwan, but it is the fastest increasing (70%) alimentary tract cancer. The aim of this study was to investigate the impact of different habits of betel nut chewing on esophageal squamous cell carcinoma (SCC) and its interaction with cigarette use and alcohol consumption.

MATERIALS AND METHODS

All 165 cases were pathologically proven esophageal SCC patients (all male, mean age = 56.0, range = 35-92 years) diagnosed by biopsy during gastroendoscopic examinations. The control group comprised 255 subjects (all male, mean age = 54.8, range = 40-92 years) selected from patients who had visited the Otolaryngology Outpatient or Inpatient Department of KMUH owing to a benign lesion over this field. All were interviewed to collect demographic and substance use information by a trained interviewer using a standardized questionnaire.

RESULTS

Smoking (aOR = 5.4, 95% CI = 2.4-12.9, PAR = 72%), alcoholic beverage drinking (aOR = 17.6, 95% CI = 9.3-35.2, PAR = 76%) and low education level are independent risk factors for esophageal cancer. Although betel nut chewers only had a borderline significant higher risk than nonchewers (aOR = 1.7; 95% CI = 0.8-3.1), those who chewed with a piece of betel inflorescence (aOR = 4.2, 95% CI = 1.4-16.0) and swallow betel-quid juice (aOR = 3.3, 95% CI = 1.3-9.3) had a significant higher risk. Significant dose-response effects were found in daily quantity of drinking and smoking. There is a synergistic effect of these three substances on the development of esophageal cancer.

CONCLUSION

Betel nut chewing plays a relevant role in the development of esophageal SCC but adds to the carcinogenetic effect of smoking and alcohol drinking. Direct mucosal contact of betel juice may contribute to its carcinogenesis.

Mutagenicity and polycyclic aromatic hydrocarbon content of fumes from heated cooking oils produced in Taiwan

According to epidemiologic studies, exposure of women to fumes from cooking oils appears to be an important risk factor for lung cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analyzed for mutagenicity in the Salmonella/microsome assay. Polycyclic aromatic hydrocarbons were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes were found to be mutagenic in the presence of S9 mix. All samples contained dibenz[a,h]anthracene (DB[a,h]A) and benz[a]anthracene (B[a]A). Concentration of DB[a,h]A and B[a]A were 1.9 and 2.2 micrograms/m3 in fumes from lard oil, 2.1 and 2.3 micrograms/m3 in soybean oil, 1.8 and 1.3 micrograms/m3 in peanut oil, respectively. Benzo[a]pyrene (B[a]P) was identified in fume samples of soybean and peanut oil, in concentrations of 19.6 and 18.3 micrograms/m3, in this order. These results provide experimental evidence and support the findings of epidemiologic observations, in which women exposed to the emitted fumes of cooking oils are at increased risk of contracting lung cancer.

Lifetime environmental exposure to tobacco smoke and primary lung cancer of non-smoking Taiwanese women

BACKGROUND

For a female population with a high lung cancer mortality rate, such as Taiwanese women, who smoke relatively rarely, but live in an environment with high male smoking prevalence, the risk and population burden of lung cancer due to environmental tobacco smoke (ETS) are relatively important.

METHODS

An age-matched case-control study was designed to investigate the effects of cumulative environmental exposure to tobacco smoke during childhood and adult life on lung cancer risk among non-smoking women in Taiwan. Information on passive smoking from all possible sources and life periods were obtained from interviews with 268 and 445 lifetime non-smoking cases and controls. Conditional logistic regression and synergism 'S' index were applied to the data to assess the independent and joint effects of passive smoking in different life stages while controlling for possible confounding variables.

RESULTS

Risks of contracting lung cancer among women near-distantly exposed to the highest level of ETS in childhood (>20 smoker-years) and in adult life (>40 smoker-years) were 1.8-fold (95% CI: 1.2-2.9) and 2.2-fold (95% CI: 1.4-3.7) higher than that among women being never exposed to ETS, and the two variables accounted for about 37% of tumours in this non-smoking female population. Children were found to be more susceptible to ETS than adults and such early exposure was found to modify the effect of subsequent tobacco smoke exposure in adult life based on an additive interaction model.

CONCLUSIONS

Environmental tobacco smoke exposure occurring in childhood potentiates the effect of high doses of exposure in adult life in determining the development of lung cancer. Smoking prohibition would be expected to protect about 37% of non-smoking Taiwanese women against lung cancer.