Association of isometric quadriceps strength with stride and knee kinematics during gait in community dwelling adults with normal knee or early radiographic knee osteoarthritis.

BACKGROUND: Identifying indicators of early knee osteoarthritis is important for preventing the onset and/or progression of the disease. Although low quadriceps strength and changes in stride and knee kinematics during gait have been suggested as possible indicators, their relevance and relationships have not been fully examined. This study aimed to analyze the association of quadriceps strength with stride and knee kinematics during gait in adults with normal knee or early knee osteoarthritis. METHODS: A total of 881 knees from 474 community dwelling adults (238 males and 236 females) were included. Radiographic images of the knee in standing position were obtained, and grading of knee osteoarthritis was classified. Isometric quadriceps strength was measured using a force detector device. Three-dimensional knee kinematics during gait was obtained by a motion capture system. Sex-based difference of quadriceps strength, stride and knee kinematics during gait was evaluated by multiple comparison among grades by sex and multiple regression of quadriceps strength was analyzed by stride and knee kinematics during gait. FINDINGS: Stride length and quadriceps strength were significantly reduced with higher grade in both sexes, and changes in knee kinematics during gait differed by sex from early knee osteoarthritis. Quadriceps strength in both sexes was significantly correlated with changes in stride length and knee kinematics during gait. INTERPRETATION: Improving quadriceps strength in early knee osteoarthritis was related with maintaining gait ability and restraining abnormal knee kinematics during gait. This may help to develop clinical approaches to prevent the onset and/or progression of knee osteoarthritis.

Risk factors for gallbladder cancer development in northern India: A gallstones-matched, case-control study.

Background & objectives: A high incidence of gallbladder cancer (GBC) is observed in northern India. This study was aimed to identify the factors involved in developing GBC in this region. Methods: A gallstones-matched, case-control study was conducted in northern India. Ninety nine patients with GBC and gallstones (33 men and 66 women, mean age of 51.4 yr) comprised the case group, while 99 patients with cholelithiasis (40 men and 59 women, mean age of 45.7 yr) comprised the control group. All participants were interviewed to complete 183 questionnaire items that included 105 food items. Potential risk factors were identified using a multivariate analysis adjusted for age and sex. Significant risk factors were identified using a stepwise logistic-regression analysis. Results: Age (≥50 yr), education (illiterate), socioeconomic status (≤below poverty line), bowel habits (≤once a day), hypertension history, hypotensive drug use, non-vegetarian diet, use of firewood for cooking, tap water drinking, hand pump water drinking and high consumption of coffee and sweets were identified as the potential risk factors. In women, factors included menarche (<13 yr), number of pregnancies (≥3 pregnancies) and parity (≥3 babies). Of these factors, age, education, bowel habits, tap water drinking and multiple pregnancy and/or multiparity were identified as significant risk factors, whereas a high consumption of coffee and sweets or hypotensive drug use and/or hypertension history were protective factors. Interpretation & conclusions: Poor bowel habits and drinking unsafe water appear to be the main risk factors for developing GBC. These are, however, modifiable factors which are capable of decreasing the risk of GBC in the north Indian population.

Plasma Helicobacter pylori Antibody Titers and Helicobacter pylori Infection Positivity Rates in Patients with Gallbladder Cancer or Cholelithiasis: a Hospital-Based Case-Control Study

Objective: Gallbladder cancer is the commonest gastrointestinal cancer in northern Indian women. Some studies have examined the association between Helicobacter pylori infection and gallbladder cancer risk, but findings have been inconsistent. We aimed to examine the association between H. pylori infection and gallbladder cancer in Indian people. Materials and Methods: We conducted a hospital-based case-control study including 100 gallbladder cancer patients with gallstones who were 32 to 79 years old (cases; 72 women and 28 men), and 100 cholelithiasis patients aged 14 to 75 years (controls; 65 women and 35 men). All patients had a diagnosis of gallbladder cancer or cholelithiasis at the Sanjay Gandhi Post Graduate Institute of Medical Sciences in Lucknow having a high gallbladder cancer incidence in northern India, from May 2014 through July 2017. Plasma samples were collected from all patients before surgical treatment. Plasma H. pylori antibody titer was measured by the latex agglutination method and an autoanalyzer. H. pylori infection was defined as antibody titer ≥10 U/mL. Plasma antibody titers and H. pylori infection positivity rates were compared between cases and controls. Results: Mean plasma antibody titers (standard deviation, range) were 11.1 U/mL (11.6, 0­78) in cases and 13.6 U/mL (23.0, 1­164) in controls. H. pylori infection positivity rates were 41% and 42% in cases and controls, respectively. No significant differences in antibody titers or H. pylori infection positivity rates were found between cases and controls. Conclusions: We found no evidence of H. pylori infection as an important risk factor for gallbladder cancer in Indian people.

Metagenomics of Microbial Communities in Gallbladder Bile from Patients with Gallbladder Cancer or Cholelithiasis

Salmonella typhi and Helicobacter infections have been shown to increase risk of gallbladder cancer (GBC), but findings have been inconsistent. Other bacterial infections may also be associated with GBC. However, information on microbial pathogens in gallbladder bile of GBC patients is scarce. We aimed to investigate the microbial communities in gallbladder bile of patients with GBC and cholelithiasis (CL). Seven GBC patients and 30 CL patients were enrolled in this study. Genomic DNA was extracted from bile and the V3-V4 region of 16S rRNA was amplified. The sequencing results were compared with the 16S database, and the bacteria were identified by homology searches and phylogenetic analysis. DNA was detected in the bile of three GBC (42.9%; Bolivia, 1; Chile, 2) and four CL patients (13.3%; Bolivia, 1; Chile, 3). Of the 37 patients, 30 (81.1%) were negative and unable to analyze. Salmonella typhi and Helicobacter sp. were not detected in bile from any GBC patients. As the predominant species, Fusobacterium nucleatum, Escherichia coli, and Enetrobacter sp. were detected in bile from GBC patients. Those in bile from CL patients were Escherichia coli, Salmonella sp., and Enerococcus gallinarum. Escherichia coli was detected in bile samples from both GBC and CL patients. Whether the bacteria detected in bile from GBC patients would associated with the development of GBC warrant further investigation.

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study.

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Lack of an Apparent Association between Mycotoxin Concentrations in Red Chili Peppers and Incidence of Gallbladder Cancer in India : an Ecological Study.

Our recent studies conducted in South America have shown that mycotoxin contamination of red chili peppers (RCPs) may be associated with an increased risk of gallbladder cancer (GBC). Whether this relationship exists in India, a country with a high incidence of GBC and high consumption of RCPs, is unclear. We therefore measured concentrations of aflatoxins (AFs) and ochratoxin A (OTA) in RCPs from areas of low, medium, and high incidence of GBC in India, and compared these concentrations with GBC incidence in each area. Twentyone RCP samples were collected from nine cities (eight from a lowincidence area, five from a mediumincidence area, and eight from a highincidence area). Concentrations of AFs and OTA were measured using highperformance liquid chromatography. No significant differences in mean concentrations of AFs and OTA were found in the three areas. AFB1 levels in the lowincidence area (10.81 ?g/kg) and highincidence area (12.00 ?g/kg) were more than 2.2 and 2.4 times higher compared with the maximum permitted level of AFB1 in spices (5.0 ?g/kg) set by the Commission of the European Communities, or that (4.4 ?g/kg) obtained in our previous study in Chile. Our results show that the mean concentrations of mycotoxins in RCPs are similar among the three areas in India with different incidences of GBC. Further studies with human subjects are needed to evaluate any association between AFB1 and GBC.

Association of mechanical factors with medial knee osteoarthritis: A cross-sectional study from Matsudai Knee Osteoarthritis Survey.

BACKGROUND: Knee osteoarthritis (OA) is a multifactorial disease that is affected by mechanical factors. The aim of present study was to investigate the association between multiple mechanical factors and medial knee OA in a large epidemiological cohort. METHODS: Six hundred and ninety-nine subjects (323 males and 376 females), participating in the Matsudai Knee Osteoarthritis Survey 2010, were included. Twelve mechanical factors were selected and their association with the radiographic grade of knee OA, the Western Ontario and McMaster University Index (WOMAC) pain score, and the WOMAC function score was evaluated. RESULTS: A logistic regression analysis identified varus thrust to be associated with the radiographic grade of knee OA in males (OR: 1.876, 95% CI: 1.332-2.663) and females (2.61, 1.922-3.542), the WOMAC pain score in males (1.997, 1.463-2.672), and the WOMAC function score in females (1.449, 1.12-1.874). Quadriceps muscle strength was associated with the radiographic OA grade in males (0.605, 0.399-0.917) and females (0.636, 0.469-0.863), the WOMAC pain score in females (0.537, 0.445-0.789), and the WOMAC function score in males (0.581, 0.44-0.766). The knee flexion angle was also associated with the radiographic OA grade in males (0.344, 0.19-0.621) and females (0.121, 0.022-0.653), and the WOMAC pain score in males (0.287, 0.156-0.53) and females (0.537, 0.336-0.859). Obesity was associated with the radiographic OA grade in males (1.543, 1.041-2.287) and females (1.589, 1.176-2.146), the WOMAC pain score in female (2.017, 1.517-2.68). Femolo-tibial angle had no significant association with the radiographic knee OA grade or with the WOMAC pain and function scores. CONCLUSION: Among patients with medial knee OA, dynamic mechanical factors, such as varus thrust, quadriceps muscle strength, and range of motion were more likely to be associated with the radiographic grade of knee OA and to be the WOMAC pain and function scores, compared to static mechanical factors.

Ochratoxin A Contamination of Red Chili Peppers from Chile, Bolivia and Peru, Countries with a High Incidence of Gallbladder Cancer.

Our previous study detected aflatoxins in red chili peppers from Chile, Bolivia, and Peru, each of which have a high incidence of gallbladder cancer (GBC). Since the aflatoxin B1 concentration was not so high in these peppers, it is important to clarify the presence of other mycotoxins. Here we attempted to determine any associations between the concentrations of aflatoxins and ochratoxin A (OTA) in red chili peppers, and the corresponding GBC incidences. We collected red chili peppers from three areas in Peru: Trujillo (a high GBC incidence area), Cusco (an intermediate GBC incidence area), and Lima (a low GBC incidence rate), and from Chile and Bolivia. Aflatoxins and OTA were extracted with organic solvents. The concentrations of aflatoxins B1, B2, G1, and G2, and OTA were measured by high-performance liquid chromatography. The values obtained were compared with the incidence of GBC in each area or country. All of the red chili peppers from the three areas showed contamination with aflatoxins below the Commission of the European Communities (EC) recommended limits (5 µg/kg), but the OTA contamination of two samples was above the EC recommended limit (15 µg/kg). The mean concentrations of OTA in the peppers from Chile (mean 355 µg/kg, range <5-1,059 µg/kg) and Bolivia (mean 207 µg/kg, range 0.8-628 µg/kg), which has a high incidence of GBC, were higher than that in Peru (14 µg/kg, range <5-47 µg/kg), which has an intermediate GBC incidence. The OTA contamination in the red chili peppers from Chile, Bolivia, and Peru was stronger than that of aflatoxins. Our data suggest that OTA in red chili peppers may be associated with the development of GBC.

Quadriceps muscle strength and its relationship to radiographic knee osteoarthritis in Japanese elderly.

BACKGROUND: Knee osteoarthritis (OA) is a multifactorial disease and strongly affected by mechanical factors. The aims of the present study were to assess validity and reliability of a new muscle strength measuring device, the Quadriceps Training Machine (QTM) and evaluate the relationship between quadriceps strength measured by QTM and radiographic knee OA by epidemiological survey. METHODS: The isometric knee extension muscle strength of QTM was compared with BIODEX in 24 healthy adults. Then, the relationship between radiographic knee OA and quadriceps strength using QTM was investigated with 2,032 knees in 1,016 subjects by an epidemiological survey (Matsudai Knee Osteoarthritis Survey). RESULTS: Significant correlation was observed between QTM and BIODEX (r = 0.69, 0.82). In the Matsudai Knee Osteoarthritis Survey, the prevalence of radiographic OA (grade II or higher upon Kellgren-Lawrence classification) was: 13, 36.9, 67.8, and 86.5 %, regarding women in their fifties, sixties, seventies, and eighties, respectively, and was 1.7, 13.4, 33.5, and 66.2 % regarding men, respectively. Quadriceps muscle strength declined following 50 years of age, and significant decline was observed in the their sixties and seventies. Quadriceps muscle strength of the OA group (grades II, III and IV) was significantly declined compared with that of the Non-OA group (grade-0 and I). Furthermore, the tendency of the muscle strength level to decline with the progression of knee OA grade was particularly observed between grade 0 and grade I in both men and women and between grade I and grade II in men. CONCLUSION: The relationship between radiographic knee OA and quadriceps strength was quantitatively evaluated by an epidemiological survey, and we found a correlation between knee OA and the decline in quadriceps strength. Furthermore, it was suggested that the decline in quadriceps muscle strength may be more strongly related to the incidence of knee OA than to its progression.

Polimorfismo genético relacionado al metabolismo de la aflatoxina y el riesgo de cáncer vesicular en mujeres chilenas / Aflatoxin metabolism-related genetic polymorphisms and the risk of gallbladder cancer in Chilean women

Background/aim: High consumption of red chili pepper has been shown to be a risk factor for gallbladder cancer (GBC) in Chilean women with gallstones (GS). GS are the main cause of GBC, but not all patients with gallstones develop GBC. Since red chili pepper is a widely consumed spice among the Chilean population, the development of GBC in Chilean women cannot be completely explained by the presence of GS and red chili pepper consumption alone. Genetic factors in addition to these and other environmental factors may also be associated with an increased risk of GBC. We aimed to study whether genetic polymorphisms involved in aflatoxin metabolism are associated with the risk of GBC in Chilean women, because we detected aflatoxins B1 and B2 in red chili pepper purchased in Santiago, Chile. Methods: We conducted a hospital-based case-control study whose subjects were 57 patients with GBC, 119 patients with GS, and 70 controls. DNA was extracted from subjects’ blood or paraffin block samples using standard commercial kits. The statuses of the genetic polymorphisms of cytochrome P450 (CYP) 1A2 rs762551 and CYP3A4 rs2740574 were assayed using the TaqMan® SNP Genotyping Assay or the Custom TaqMan® SNP Genotyping Assay, respectively. Results: In the assay for the CYP1A2 polymorphism, of the 57 GBC patients, 23 (40.3 percent) had at least one minor allele (A/C or C/C). However, there were no significant differences in the genotypic or allelic frequencies among the three subject groups. In the assay for the CYP3A4 polymorphism, the minor G/G genotype was not detected in the three groups, and there were no significant differences in the genotypic or allelic frequencies among the three groups. Conclusion: These genetic polymorphisms were not related to the risk of GBC in Chilean women. Further studies including a greater number of controls and cases are needed to confirm this preliminary exploratory result.

Introducción/objetivo: El alto consumo de ají rojo ha demostrado ser un factor de riesgo de cáncer vesicular (CV) en mujeres chilenas con cálculos vesiculares. Los cálculos vesiculares son la causa principal de CV, no obstante, no todos los pacientes con cálculos vesiculares desarrollan CV. Debido a que el ají rojo es una especia ampliamente consumida entre la población chilena, el desarrollo de CV en las mujeres chilenas no puede ser explicado en su totalidad sólo por la presencia de cálculos vesiculares y consumo de ají rojo. Factores genéticos además de éstos y otros factores ambientales, también podrían estar relacionados con un aumento del riesgo de CV. Nuestro objetivo es estudiar si los polimorfismos genéticos involucrados en el metabolismo de la aflatoxina están relacionados con el riesgo de CV en mujeres chilenas, porque detectamos aflatoxinas B1 y B2 en ajíes rojos comprados en Santiago de Chile. Métodos: El estudio caso control, incluyó 57 pacientes con CV, 119 pacientes con cálculos vesiculares, y 70 controles. Se extrajo ADN de la sangre de los sujetos o de bloques de parafina, usando kits comerciales estándar. El estado de los polimorfismos genéticos del citocromo P450 (CYP) 1A2 rs762551 y CYP3A4 rs2740574 fueron estudiados usando el ensayo de genotipo SNP TaqMan® o el ensayo de genotipo SNP Custom TaqMan®, respectivamente. Resultados: En el ensayo para el polimorfismo CYP1A2, de los 57 pacientes con CV, 23 (40,3 por ciento) tuvieron al menos un alelo menor (A/C o C/C). No obstante, no hubo diferencias significativas en las frecuencias genotípicas o alélicas entre los tres grupos. En el ensayo para el polimorfismo CYP3A4, el genotipo menor G/G no fue detectado en los tres grupos, y no hubo diferencias significativas en las frecuencias genotípicas o alélicas entre los tres grupos. Conclusión: Estos polimorfismos genéticos no estaban relacionados con el riesgo de CV en mujeres chilenas...

Changes in pancreatic cancer mortality, period patterns, and birth cohort patterns in Japan: analysis of mortality data in the period 1968-2002.

OBJECTIVES: The 5-year survival rate for pancreatic cancer is known to be lower than that for cancer at any other site in the body, and the proportion of pancreatic cancer deaths among all cancer deaths has been increasing in Japan. The aim of this study was to investigate pancreatic cancer mortality in the light of temporal and geographical trends in the 47 prefectures of the country between 1968 and 2002. METHODS: To survey the geographical aspects of pancreatic cancer mortality, we mapped the direct age-adjusted mortality rates of persons aged 40 years and older by sex in seven 5-year periods (1968-1972 to 1998-2002). We also evaluated the changes in period and birth cohort trends using estimable functions based on the age-period-cohort models in each prefecture. RESULTS: During the observation period the Hokkaido and Tohoku regions had high mortality rates for both sexes. No significant increase in period trends was observed from 1973 to 2002, but significant increases in cohort trends were observed from 1913 to 1962-in two prefectures, for males, and in four prefectures, for females. CONCLUSIONS: The results of this study reveal a combination of time trends in pancreatic cancer mortality and changes in period or birth cohort trends. The changes in cohort trends in each prefecture were more variable than the period trends. This finding probably indicates the need for further investigation of the cohort-related factors involved in the prevalence of pancreatic cancer. Further research on mortality in the 47 prefectures needs to be conducted while taking the two time effects into account.

[Descriptive epidemiologic studies on geographical clusterings of pancreatic cancer mortality and incidence--an analysis in Niigata, Japan].

OBJECTIVES: The objectives of this study were to determine the mortality for pancreatic cancer in the 47 prefectures of Japan and to reveal the geographical distribution of the mortality and incidence for pancreatic cancer in Niigata. METHODS: Standardized mortality ratio (SMR) for pancreatic cancer in the 47 prefectures from 1998 to 2002 was calculated on the basis of the census and vital statistics of Japan. The same SMR in the 36 cities and counties in Niigata from 1995 to 2002 was calculated. These SMRs were compared with that of the national population. Then, standardized incidence ratio (SIR) for pancreatic cancer in the 36 cities and counties in Niigata from 1995 to 2002 was calculated on the basis of the Niigata Cancer Registry, compared with that of the general population of Niigata. RESULTS: The SMRs for pancreatic cancer for both sexes in Hokkaido, Aomori, Akita, Miyagi and Shimane were significantly higher than that of the national population (p<0.05). The SMR for males in Niigata was significantly high, whereas that for females was near the SMR of the national population. Among the 36 cities and counties in Niigata, significantly high SMRs for both sexes were observed only in Higashikanbara county; the SMRs [95% confidence interval (CI)] were 158.4 (104.4-230.5) and 172.2 (114.4-248.9) for males and females, respectively. CONCLUSIONS: Significantly high SMRs for pancreatic cancer were observed in Hokkaido and most of the Tohoku region. A geographical clustering of pancreatic cancer in Higashikanbara county was found. Further studies are needed to clarify the determinants of the clustering.

Phase II study of carboplatin and weekly paclitaxel combination chemotherapy in advanced non-small cell lung cancer: a Kansai Clinical Oncology Group study.

The objective of this phase II study was to evaluate the efficacy and toxicity of carboplatin and weekly paclitaxel combination chemotherapy in previously untreated, advanced non-small cell lung cancer (NSCLC). Patients received paclitaxel at a dose of 70 mg/m(2) on days 1, 8, 15, and carboplatin with the target dose of area under the curve (AUC) of 6 on day 1 every 28 days. Forty-six patients were enrolled. A median of four cycles (range, 1-13) were administered. Complete response was observed in one patient (2.2%) and partial response in 23 patients (50%), yielding an overall intent-to-treat response rate of 52.2% (95% confidence interval, 37.8-66.6%). The median survival time was 395 days and 1-year survival rate was 51.4%. Toxicities were mild. Twelve patients (26%) had grade 3 and three patients (7%) had grade 4 neutropenia. Grade 3 thrombocytopenia was seen in four patients (8%). Massive hematoemesis due to duodenal ulcer was observed in one patient, but no other patients experienced grade 3 or more non-hematological toxicities. There was no treatment-related death. Carboplatin and weekly paclitaxel combination chemotherapy is an efficacious and feasible regimen in patients with advanced NSCLC, and this treatment will be a reasonable alternative to the conventional triweekly regimen of paclitaxel and carboplatin.

Association of chili pepper consumption, low socioeconomic status and longstanding gallstones with gallbladder cancer in a Chilean population.

We explored the risk factors for gallbladder cancer and explanations for its sharp and constant incidence increase in Chile since the 1970s. We compared 114 consecutive patients with verified gallbladder cancer, diagnosed 1992-1995, to 114 matched hospital patients with gallstones, using conditional logistic regression analysis. Low education showed a nonsignificant positive relationship with gallbladder cancer [odds ratio (OR) = 2.3, 95% confidence interval (CI) 0.8-6.2], and low socioeconomic level showed a significant relationship (OR = 5.0, 95% CI 1.5-17.3). A very long history of gallstone disease was significantly more prevalent among cases (OR = 11.0, 95% CI 1.4-85.2). Significant red chili pepper consumption was observed in gallbladder cancer patients (OR = 2.9, 95% CI 1.6-5.2). Low intake of both fresh fruit and sugar as soft drinks was associated with gallbladder cancer, with ORs of 6.4 (95% CI 1.4-30.3) and 3.6 (95% CI 1.3-10.1), respectively. Multivariate analysis kept only a very low socioeconomic status and red chili pepper consumption as significant independent risk factors for gallbladder cancer, ORs of 6.3 (95% CI 1.7-23.0) and 3.2 (95% CI 1.7-5.9). Longstanding gallstone cases were removed from the multivariate model because all were in the low and very low socioeconomic groups, reinforcing the association. Patients with gallbladder cancer differed from matched controls by exhibiting lower socioeconomic levels, having a much longer history of gallstone disease and presenting a dietary pattern characterized by high red chili pepper consumption and low fresh fruit intake.

Elevated mortality from lung cancer associated with arsenic exposure for a limited duration.

In 1959, arsenic poisoning was detected in the town of Nakajo in Japan. The cause was exposure to inorganic arsenic in well water during 1954 to 1959. To examine the long-term effects of limited-duration arsenic exposure, we conducted mortality and survival studies for patients with chronic arsenic exposure and for control subjects from 1959 to 1992. The ratio of observed deaths to expected deaths from lung cancer was significantly high (7:0.64) for male patients. The lung cancer mortality rate was elevated markedly in subgroups with higher clinical severities of symptoms. Small cell carcinoma was specific to the exposed patients. The cumulative change of survival declined significantly in the exposed patients compared with the controls. The decline disappeared when lung cancer deaths were treated as lost to follow-up. The results showed that a 5-year period of arsenic exposure was associated with risk of lung cancer.

Cáncer vesicular: estudio de casos y controles en Chile / Gallbladder cancer: estudy of cases and controls in Chile

Estudio epidemiológico analítico de casos y controles, con 90 pacientes de cáncer vesicular verificado histológicamente y dos grupos de controles pareados por sexo y edad, uno con colelitiasis sin cáncer (colecistectomizados) y el otro, sin colelitiasis ni cáncer, según verificación ecográfica y seguimiento, completando 180 controles. A todos los enfermos se les aplicó una encuesta especialmente diseñada con 198 variables sociodemográficas, otras condiciones y patologías personales y familiares, medicamentos y algunos hábitos, especialmente de alimentación. Se encontró como factores de riesgo: antecedente de neoplasia familiar, mayor tiempo de evolución de la litiasis biliar y consumo aumentado de grasas y particularmente de ají en sus variedades verde y roja