Mortality among Soviet and Russian cosmonauts: 1960-2013.

INTRODUCTION: Though the mortality of U.S. astronauts has been studied repeatedly in the last 20 yr, little is known about the long-term mortality trends of Soviet and Russian cosmonauts. METHODS: Using data from 266 cosmonauts accepted into cosmonaut training from 1960 to 2013, we document the causes of death and crude death rates among cosmonauts. Using standardized mortality ratios (SMR), we compared cosmonauts to the general populations of Russia and Ukraine, and to 330 U.S. astronauts. RESULTS: Cosmonauts experienced significantly lower all-cause mortality risk compared to the general population. However, cosmonauts were at almost double the risk of all-cause mortality in comparison to U.S. astronauts (SMR = 190, 95% C.I. 154-239). Cosmonauts were also at greater risk of circulatory disease (SMR = 364, 95% C.I. 225-557) and cancer (SMR = 177, 95% C.I. 108-274) compared to U.S. astronauts. Though not statistically significant, cosmonauts experienced fewer fatal accidents (SMR = 88, 95% C.I. = 54-136) than their U.S. counterparts. DISCUSSION: Cosmonauts are at much lower risk of all-cause mortality than the general populations of Russia and Ukraine, yet are at greater risk for death by cardiovascular disease and cancer than are U.S. astronauts. This disparity may have common roots with decreases in life expectancy in Russia in recent decades. Further research is needed to understand these trends fully.

Utilization of lymph node dissection, race/ethnicity, and breast cancer outcomes.

OBJECTIVES: Although large differences by race/ethnicity in breast cancer survival are well established, it is unknown whether disparities in nodal surgery utilization explain the racial/ethnic disparities in survival among women with micrometastasis and macrometastasis in sentinel lymph nodes (SLNs). STUDY DESIGN: Retrospective cohort study. METHODS: Women with breast cancer who underwent sentinel lymph node biopsy (SLNB) and who were found to have nodal metastases were identified from the Surveillance, Epidemiology, and End Results database (1998-2005). Outcomes data were examined for patients who underwent SLNB alone versus SLNB with axillary lymph node dissection (ALND). RESULTS: Proportions of patients receiving SLNB alone or receiving SLNB with a complete ALND were not statistically different among women of different racial/ethnic backgrounds (P = .8). Patients of African American descent or Hispanic origin had reduced overall survival, whereas patients of Hispanic origin had reduced diseasespecific survival after adjusting for selected covariates. Adjusting for nodal surgery did not reduce racial/ethnic disparities in overall survival or disease-specific survival. CONCLUSIONS: The disparities in survival among African American and Hispanic women with breast cancer are not explained by nodal surgery utilization among women with micrometastasis and macrometastasis in SLNs.

Exposure to antibiotics in a United States-Mexico border birth cohort.

OBJECTIVE: The goal was to compare the frequency of children's antibiotic intake, emphasizing antibiotics with anti-Helicobacter pylori effects, in El Paso, Texas, and Juarez, Mexico. METHODS: Hispanic children were enrolled prenatally at mother-child clinics in El Paso, and Juarez, in 1998-2000, to identify determinants of H pylori infection. During follow-up examinations targeted every 6 months from 6 to 84 months of age, caretakers reported medication use during the preceding interval. Courses of any systemic and H pylori-effective antibiotics were compared for US and Mexican children. RESULTS: Antibiotic data were available for 602 children, from 2938 follow-up visits. Overall antibiotic intake was higher in Juarez, where 84% of children received > or = 1 course during the follow-up period (52% of visits), compared with El Paso, where 76% of children received > or = 1 course (40% of visits). In contrast, the intake of H pylori-effective antibiotics was higher in El Paso, where 65% of children received > or = 1 course during the follow-up period (27% of visits), compared with Juarez, where 44% of children received > or = 1 course (16% of visits). Of H pylori-effective courses, 94% contained amoxicillin and 2% each clarithromycin, metronidazole, and furazolidone; uses were primarily for throat and ear infections, diarrhea, and cold/flu. CONCLUSIONS: Pediatric antibiotic use was higher in Mexico than on the US side of the border. Apparent misuse of H pylori-effective antibiotics was more frequent in Juarez but also occurred in El Paso. Such misuse of antibiotics may lead to drug resistance and may impair the control of H pylori infection in this region.

Gene expression in Barrett's esophagus: laser capture versus whole tissue.

OBJECTIVE: Diagnosis of Barrett's esophagus (BE) is typically done through morphologic analysis of esophageal tissue biopsy. Such samples contain several cell types. Laser capture microdissection (LCM) allows the isolation of specific cells from heterogeneous cell populations. The purpose of this study was to determine the degree of overlap of the two sample types and to define a set of genes that might serve as biochemical markers for BE. MATERIAL AND METHODS: Biopsies were obtained from regions of the glandular tissue of BE and normal esophagus from 9 subjects with BE. Samples from 5 subjects were examined as whole tissue (BE [whole]; E [whole]), and in 4 subjects the glandular epithelium of BE was isolated using LCM (BE [LCM]) and compared with the averaged values (E [LCM]) for both basal cell (B [LCM]) and squamous cell (S [LCM]) epithelium. RESULTS: Gene expression revealed 1797 probe sets between BE [whole] and E [whole] (fold change > 2.0; p<0.001). Most of these genes (74%) were also differentially expressed between BE [LCM] and E [LCM], showing that there was high concordance between the two sampling methods. LCM provided a great deal of additional information (2113 genes) about the alterations in gene expression that may represent the BE phenotype. CONCLUSIONS: There are differences in gene expression profiles depending on whether specimens are whole tissue biopsies or LCM dissected. Whole tissue biopsies should prove satisfactory for diagnostic purposes. Because the data from LCM samples delineated many more Barrett's-specific genes, this procedure might provide more information regarding pathogenesis than would whole tissue material.

Epidemiology and transmission of hepatitis B and C viruses in Kazakhstan.

AIM: To investigate the epidemiology of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in the two major ethnic groups in Kazakhstan. METHODS: A cross-sectional prospective study of HBV and HCV seroprevalence was performed among individuals born in Kazakhstan with no history of chronic hepatitis or liver disease. RESULTS: There were 290 volunteers (140 Russians and 150 Kazakhs) aged 10 to 64 years, males accounted for 46%. Active HBV infection (HBsAg positive) was present in 3.8%, anti-HBc in 30%. The prevalence was similar in females and males (33% vs 25%) (P = 0.18). The prevalence of anti-HBc increased from 19% in 10-29 years old volunteers to 53% in 50-years and older volunteers. The prevalence of HBV infection was higher in married than in single adults (38% vs 26%, respectively) (P = 0.2) and more common in Kazakhs (35%) than in Russians (24%) (P = 0.07). HCV infection was present in 9 subjects (3.2%), 5 of them also were positive for anti-HBc in the absence of HBsAg. CONCLUSION: The frequency of active HBV infection (3.8%) coupled with a high prevalence of HBV exposure in those > 50 years of age increases with age, which suggests that horizontal transmission likely relates to the use of contaminated needles. The low prevalence of HCV infection suggests that HBV and HCV are acquired differently in this group of subjects.

Point-of-care Helicobacter pylori urine antibody detection in a multi-ethnic adult population in the United States.

A need exists for accurate point-of-care tests for diagnosis of Helicobacter pylori (H. pylori) infection to evaluate a rapid urine-H. pylori antibody test device for detection of H. pylori infection in a point-of-care setting in the United States. A multi-center study in a multi-ethnic population compared the RAPIRUN urine antibody test with the (13)C-urea breath test (C-UBT) and a traditional serologic test, the high-molecular-weight cell-associated protein enzyme immunoassay (HM-CAP EIA). The primary comparator was with "definite positive" and "definite negative" patients defined as a concordance of combined results of the UBT and the HM-CAP IgG EIA. Overall, 188 eligible patients were enrolled (61 men, age range: 18-73 years, including 84 Hispanics, 73 Asian-Pacific Americans, 22 Black African-Americans, 6 non-Hispanic Caucasians, and 3 of "other" ethnicity). Compared with "definite positive" and "definite negative" results, the sensitivity and specificity of the urine antibody test were 0.9 and 1.0, respectively. The urine antibody test proved suitable for point-of-care rapid diagnosis of anti-H. pylori antibodies indicative of active or past H. pylori infection.

Problem of distinguishing false-positive tests from acute or transient Helicobacter pylori infections.

BACKGROUND: Reliable detection of acute Helicobacter pylori infections remains problematic. The high prevalence of false-positive non-invasive tests in low H. pylori prevalence populations makes identification of acute and transient infections difficult. METHODS: We explored the use of serum pepsinogens (PG) for diagnosis of acute infection in patients following H. pylori challenge such that the onset of the infection was known. We then compared those findings to a group of children with presumed acute infections defined as a positive urea breath test (UBT) and negative IgG serology. RESULTS: We examined the pattern and calculated cut-off values of PG levels in 18 adult volunteers with known acute H. pylori infection. We then compared the results with sera from nine symptomatic children with presumed acute H. pylori infection and a matched control group of nine children who did not meet criteria for acute H. pylori infection. In acute infection, both PGI and II levels increased following H. pylori infection reaching a peak by 2 weeks post-infection. The frequency of a positive test defined as a value > mean +2 SD was 17, 71, and 94% at week 1, 2, and 4 post-infection, respectively. Only one child with presumed acute H. pylori infection had an elevated serum PGI and one had an elevated PGII. Five of the children had follow-up UBTs and four were negative consistent with the diagnosis of false-positive UBT. H. pylori infection was confirmed in the child with an elevated PGI level. CONCLUSIONS: These data suggest that a single positive noninvasive test in populations of low prevalence is most likely a false-positive result. This suggests that a single positive test requires confirmation preferably using a test that measures a different parameter (e.g., UBT confirmed by stool antigen test). It appears that most "transient"H. pylori infections are diagnosed on the basis of false-positive tests. PG levels are possible candidates as the confirmatory test.

Noninvasive versus histologic detection of gastric atrophy in a Hispanic population in North America.

BACKGROUND & AIMS: Cancer risk is directly correlated with the severity and extent of mucosal atrophy, making identification of atrophy a goal in cancer prevention programs. The aim of this study was to compare targeted histology with noninvasive testing for the identification of antral and/or corpus atrophy in North America. METHODS: In a cross-sectional study of a random sample of households, 8 gastric biopsy specimens were obtained from defined locations in the antrum and corpus. Biopsies were scored for the presence of Helicobacter pylori and gastric atrophy (defined as loss of normal glandular components). Atrophy was scored by using the Sydney system and a system based on the number and location of corpus biopsies with atrophy. Patients' sera were examined for pepsinogen I, pepsinogen II, and gastrin-17 (fasting and stimulated). RESULTS: One hundred eighty volunteers, approximately 30 per age group and ranging in age from 18-82 years, participated. There were 76 men. The overall weighted prevalence of a corpus atrophy was 4.7% (95% confidence interval, 2.3-7.0). There was a significant inverse relationship between the grade of corpus atrophy and the pepsinogen I/pepsinogen II ratio (R = -0.31, P < .01). We failed to confirm the usefulness of the proposed algorithm by using gastrin-17, H. pylori serology, and serum pepsinogens to categorize the gastric histology. The Sydney system underestimated the prevalence of corpus atrophy by approximately 25%. CONCLUSION: Noninvasive testing is both possible and practical by using pepsinogen assays for the identification of the precancerous condition of moderate to severe corpus atrophy in North American Hispanic patients.

B-cell and T-cell immune responses to experimental Helicobacter pylori infection in humans.

The acute antibody and T-cell immune response to Helicobacter pylori infection in humans has not been studied systematically. Serum from H. pylori-naive volunteers challenged with H. pylori and cured after 4 or 12 weeks was tested by enzyme-linked immunosorbent assays for anti-H. pylori-specific immunoglobulin M (IgM) and IgA established using bacterial lysates from homologous (the infecting strain) and heterologous H. pylori. Proteins recognized by IgM antibody were identified by mass spectrometry of immunoreactive bands separated by two-dimensional gel electrophoresis. Mucosal T-cell subsets (CD4, CD8, CD3, and CD30 cells) were assessed by immunohistochemistry. All 18 infected volunteers developed H. pylori-specific IgM responses to both homologous or heterologous H. pylori antigens. H. pylori antigens reacted with IgM antibody at 4 weeks postinfection. IgM Western blotting showed immunoreactivity of postinfection serum samples to multiple H. pylori proteins with molecular weights ranging between 9,000 (9K) to 150K with homologous strains but only a 70K band using heterologous antigens. Two-dimensional electrophoresis demonstrated that production of H. pylori-specific IgM antibodies was elicited by H. pylori flagellins A and B, urease B, ABC transporter binding protein, heat shock protein 70 (DnaK), and alkyl hydroperoxide reductase. Mucosal CD3, CD4, and CD8 T-cell numbers increased following infection. IgM antibody responses were detected to a range of homologous H. pylori antigens 2 to 4 weeks postchallenge. The majority of H. pylori proteins were those involved in motility and colonization and may represent targets for vaccine development.

Polyomavirus SV40 infections in Kazakhstan.

OBJECTIVES: To examine the prevalence of polyomavirus SV40 infections in Kazakhstan, a central Asian country known to have used potentially contaminated SV40 poliovaccines before 1962. METHODS: Cross-sectional study of 307 healthy volunteers from two ethnic groups (Kazakhs and Russians) in Almaty, Kazakhstan, from May through August 1999 using a specific SV40 plaque-reduction neutralization assay. RESULTS: Of the 307 volunteers enrolled in the study, 154 were Kazakhs and 153 were Russians. The overall prevalence of SV40 antibodies was 4.9%, and there was no significant difference between the ethnic groups (p = 0.7) or between males and females. The median SV40 neutralizing antibody titers in Kazakhs and Russians were 1:40 (range 1:10-1:500) and 1:20 (range 1:10-1:500), respectively. The median ages of SV40-infected Kazakhs and Russians were not different (42 vs. 24 years; p = 0.1), although there was a trend for increased seropositivity among older Kazakhs. There was no difference in SV40 positivity between those whose childhoods were spent in rural or in urban areas (p = 0.4). Importantly, 60% (9/15) of the subjects seropositive for SV40 were born from 1969 to 1980s, when poliovaccines were free from SV40. CONCLUSIONS: This study showed evidence of polyomavirus SV40 infections in Kazakhstan, not only among individuals potentially exposed to contaminated poliovaccines, but in younger people not exposed to such vaccines. As increasing evidence indicates an association of SV40 with selected types of human malignancies, prospective studies are needed to examine the risk of SV40 infection with the development of neoplasias.

A pilot study of Helicobacter pylori infection and risk of laryngopharyngeal cancer.

BACKGROUND: Squamous cell carcinoma of the laryngopharynx has been linked to laryngopharyngeal reflux disease. Helicobacter pylori corpus gastritis decreases gastric acid secretion and provides some protection against complications of gastroesophageal reflux, including adenocarcinoma of the distal esophagus. The aim of this study was to investigate whether H. pylori infection also protects against laryngopharyngeal carcinoma. METHODS: This was a case-control study comparing patients with histologically confirmed, previously untreated laryngeal or pharyngeal squamous cell carcinomas with cancer-free controls selected from a pool of hospital-based cancer-free controls identified during a similar time period. Each subject completed a self-administered questionnaire that elicited information on age, sex, ethnicity, and tobacco and alcohol consumption. The 120 case subjects were frequency matched to 120 control subjects on age (+/- 5 years), sex, tobacco use, and alcohol use; all subjects were non-Hispanic whites. H. pylori and human papillomavirus type 16 (HPV-16) seropositivity was determined by use of an enzyme-linked immunosorbent assay. RESULTS: The serologic assay was unsuccessful in one case subject and nine control subjects; therefore, 119 case subjects and 111 control subjects were included in the analysis. The proportion of subjects with anti-H. pylori immunoglobulin G was similar between the two groups (32.8% among cases vs 27.0% among controls; p = .342). Although seropositivity was more common in the patients with laryngeal cancer (39.1%) than in the patients with pharyngeal cancer (28.8%), this difference was neither significant (p = .241) nor associated with a significant risk of laryngeal cancer (adjusted odds ratio, 1.53; 95% confidence interval, 0.69-3.41). H. pylori seropositivity was more common among patients who were HPV-16 seronegative (38.2% vs 22.9%, p = .081), and this was particularly true among patients with laryngeal cancer (47.1% vs 18.2%; p = .089). CONCLUSIONS: These results do not show that H. pylori infection either protects against or promotes laryngopharyngeal carcinoma. However, segregation analyses suggested that H. pylori may play a role in laryngeal cancers not associated with HPV-16 infection, and further study in this group is warranted.

Correlation between Helicobacter pylori OipA protein expression and oipA gene switch status.

Polyclonal antisera to either a synthetic OipA peptide or a recombinant OipA protein detected OipA expression in Helicobacter pylori and correlated with functional oipA status determined by PCR sequence (sensitivity and specificity of >94%). Immunoblotting is a simple and accurate method for detecting expression of the important virulence factor OipA.

Helicobacter pylori infection in Kazakhstan: effect of water source and household hygiene.

The epidemiology of Helicobacter pylori infection and risk factors associated with its transmission are not well understood. Kazakhstan is country with two ethnic groups, Asian (Kazakhs) and Western (Russians), living under similar socioeconomic conditions. The aim of this study was to examine the seroepidemiologic pattern of H. pylori and hepatitis A among the same individuals from both ethnic groups, with emphasis on water source and household sanitation practices. This was a cross-sectional seroepidemiologic study conducted among unrelated healthy individuals in Kazakhstan. From May through August 1999, individuals between the ages of 10 and 60 years from Almaty, Kazakhstan, were invited to participate. Demographic information, socioeconomic factors, living conditions, and various aspects of the local household environment including access to water were collected. A clean water index (CWI) was created based on combined factors, consistency of boiling water before drinking, frequency of storing and reusing water, and frequency of bathing and showering. H. pylori and hepatitis A antibodies were assessed by enzyme-linked immunosorbent assay. Two hundred eighty-eight individuals between the ages of 10 and 60 years participated. The prevalence of H. pylori infection was almost identical among the two ethnic groups (Russians 79% and Kazakhs 80%). H. pylori infection was inversely correlated with the CWI (i.e., 56%, 79%, and 95% for high, middle, and low, respectively (P < .05). Drinking river water had highest risk of H. pylori infection (OR = 13.6, 95% CI = 1.8-102.4; P < .01, compared with tap water). Crowding showed no significant effect on H. pylori prevalence. Anti-HAV antibodies were found in 86% of the population, 90% among the Russians versus 82% among the Kazakhs (OR = 1.8, 95% CI = 1.1-3.8, P = .05). Although the two infections were highly correlated (P < .001), antibody to both infections were present simultaneously in only 74%. The prevalence of H. pylori infection in Kazakhstan is very high. The data suggest that transmission of H. pylori can be water borne, related to poor sanitary practices, or both. The high prevalence of antibodies to H. pylori and HAV among this population is a marker for poor sanitation and hygienic practices. Reducing the rate of H. pylori transmission will require improvements in overall sanitation including clean water, waste disposal, as well as in household hygienic practices.