Giardia and Cryptosporidium antibody prevalence and correlates of exposure among Alaska residents, 2007-2008.

Giardia duodenalis and Cryptosporidium spp. are common intestinal protozoa that can cause diarrhoeal disease. Although cases of infection with Giardia and Cryptosporidium have been reported in Alaska, the seroprevalence and correlates of exposure to these parasites have not been characterised. We conducted a seroprevalence survey among 887 residents of Alaska, including sport hunters, wildlife biologists, subsistence bird hunters and their families and non-exposed persons. We tested serum using a multiplex bead assay to evaluate antibodies to the Giardia duodenalis variant-specific surface protein conserved structural regions and to the Cryptosporidium parvum 17- and 27-kDa antigens. Approximately one third of participants in each group had evidence of exposure to Cryptosporidium. Prevalence of Giardia antibody was highest among subsistence hunters and their families (30%), among whom positivity was associated with lack of community access to in-home running water (adjusted prevalence ratio [aPR] 1.15, 95% confidence interval (CI) 1.02-1.28) or collecting rain, ice, or snow to use as drinking water (aPR 1.09, 95% CI 1.01-1.18). Improving in-home water access for entire communities could decrease the risk of exposure to Giardia.

The diagnosis and treatment of Helicobacter pylori infection in Arctic regions with a high prevalence of infection: Expert Commentary.

Helicobacter pylori infection is a major cause of peptic ulcer and is also associated with chronic gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and adenocarcinoma of the stomach. Guidelines have been developed in the United States and Europe (areas with low prevalence) for the diagnosis and management of this infection, including the recommendation to 'test and treat' those with dyspepsia. A group of international experts performed a targeted literature review and formulated an expert opinion for evidenced-based benefits and harms for screening and treatment of H. pylori in high-prevalence countries. They concluded that in Arctic countries where H. pylori prevalence exceeds 60%, treatment of persons with H. pylori infection should be limited only to instances where there is strong evidence of direct benefit in reduction of morbidity and mortality, associated peptic ulcer disease and MALT lymphoma and that the test-and-treat strategy may not be beneficial for those with dyspepsia.

Reinfection after successful eradication of Helicobacter pylori in three different populations in Alaska.

We performed a study to determine rates of reinfection in three groups followed for 2 years after successful treatment: American Indian/Alaska Native (AI/AN) persons living in urban (group 1) and rural (group 2) communities, and urban Alaska non-Native persons (group 3). We enrolled adults diagnosed with H. pylori infection based on a positive urea breath test (13C-UBT). After successful treatment was documented at 2 months, we tested each patient by 13C-UBT at 4, 6, 12 and 24 months. At each visit, participants were asked about medication use, illnesses and risk factors for reinfection. We followed 229 persons for 2 years or until they became reinfected. H. pylori reinfection occurred in 36 persons; cumulative reinfection rates were 14·5%, 22·1%, and 12·0% for groups 1, 2, and 3, respectively. Study participants who became reinfected were more likely to have peptic ulcer disease (P = 0·02), low education level (P = 0·04), or have a higher proportion of household members infected with H. pylori compared to participants who did not become reinfected (P = 0·03). Among all three groups, reinfection occurred at rates higher than those reported for other US populations (<5% at 2 years); rural AI/AN individuals appear to be at highest risk for reinfection.

Successful transfer of passive immunity: the natural alternative to antibiotics for boosting the survival of intensively reared dairy goat kids.

In dairy operations, antibiotics have traditionally been used to treat, prevent, and control diseases. However, given the mounting global crisis of antimicrobial resistance (AMR), farmers are urged to re-assess and reduce their reliance on antibiotics. Thus, this randomized, double-blinded cohort study aimed to estimate the prevalence of failed and successful transfer of passive immunity (FTPI and STPI) in dairy goat kids reared under commercial conditions, and the effects of antibiotic metaphylaxis on the pre-weaning (≤42 d old) mortality in FTPI and STPI kids. Plasma concentration of immunoglobulin G at 1d old (pIgG-24 h) was measured in 747 male Saanen kids for the determination of FTPI and STPI (pIgG-24 h < 12 and ≥12 g/L, respectively). Kids were then randomly divided into two groups: those receiving a single penicillin injection at 1 d old (PEN), and those receiving no treatment (CTR). The mean (±SD) pIgG-24 h and initial BW (IBW) were 17 ± 9.8 g/L and 4.1 ± 0.64 kg. The prevalence of FTPI was 29% (220/747 kids). Gastrointestinal complications were the primary cause of death (41%), followed by septicemia (22%) and arthritis (17%). A single penicillin injection reduced preweaning mortality by 55% (10 vs 22%, PEN vs CTR). However, results suggest that such a decline was mainly driven by the improved survival rates among FTPI kids, which increased by 19% (from 62% in CTR-FTPI to 82% in PEN-FTPI), as opposed to an 8% increase among STPI kids (from 85% in CTR-STPI to 93% in PEN-STPI). Additionally, the odds of mortality ≤ 42 d old were threefold higher in the CTR-FTPI group when compared to both the CTR-STPI and PEN-FTPI groups, suggesting a potential parity between STPI and PEN for mortality rate reduction. Taken together, the results indicate that although metaphylactic antibiotics can halve preweaning mortality, similar improvements are likely to be achieved via increased STPI rates. Furthermore, by targeting metaphylactic interventions to high-risk groups (i.e., those displaying signs of inadequate colostrum intake and/or low birth BW), farmers could reduce treatment costs and mitigate AMR risks. While these findings carry considerable weight for commercial dairy goat practices, their applicability to other systems (i.e., extensive, semi-intensive, mohair, meat systems) warrants further investigation.

Evaluation of plasma immunoglobulin G and BW thresholds for predicting preweaning mortality in commercially raised dairy goat kids.

The high preweaning mortality rate is a concerning issue for the commercial dairy industry. In this context, early identification of at-risk individuals can be instrumental. To address this, we conducted a prospective cohort study with the objective of evaluating plasma immunoglobulin G concentration (pIgG-24 h) and initial BW (IBW) measured at 1d old in 363 male dairy kids (Saanen) for predicting preweaning mortality under commercial conditions. Receiver operator characteristic (ROC) analysis was used to determine critical thresholds for pIgG-24 h and IBW. Subsequently, areas under the curve (AUC), sensitivity (Se), and specificity (Sp) were examined to assess the accuracy of these thresholds. Multivariable regressions were used to model odds ratios (OR) for mortality, controlling for confounding effects between IBW and pIgG-24 h. The mean (±SD) pIgG-24 h and IBW were 16.4 ± 9.37 g/L and 4.0 ± 0.61 kg. Overall mortality ≤ 14d and ≤42d old was 12% and 21%, respectively. Critical pIgG-24 h thresholds predicting mortality ≤ 14 d and ≤42 d old were < 10.1 g/L (AUC = 0.74, Se = 59%, and Sp = 82%) and <11.4 g/L (AUC 0.70, Se = 53%, and Sp = 77%), respectively. Kids with pIgG-24 h < 10.1 g/L were six times more likely to die ≤ 14 d old [OR; 95% CI (6; 3-12)], and kids with pIgG-24 h < 11.4 g/L were four times more likely to die ≤ 42 d old (4; 2-6). The IBW threshold most linked to mortality ≤ 14 d was <3.95 kg (AUC 0.60, Se = 59%, and Sp = 61%). However, this association became inconclusive after adjusting for pIgG-24 h differences. Conversely, an IBW of <3.0 kg was associated with notably higher mortality odds within both 14 and 42 d, irrespective of pIgG-24 h levels (10; 3-37, and 4; 1-20, respectively), suggesting that kids with an IBW < 3.0 kg face an increased likelihood of dying before 42 d, irrespectively of their IgG levels. While our findings suggest pIgG-24 h < 11.4 g/L and IBW < 3.0 kg as strong indicators of early mortality risks in male dairy kids, these results require further validation for other systems.

The International Circumpolar Surveillance interlaboratory quality control program for Streptococcus pneumoniae, 1999 to 2008.

The International Circumpolar Surveillance (ICS) Program was initiated in 1999 to conduct population-based surveillance for invasive pneumococcal disease in select regions of the Arctic. An interlaboratory quality control (QC) program for pneumococcal serotyping and antibiotic susceptibility testing was incorporated into ICS by reference laboratories in northern Canada (Laboratoire de Santé Publique du Québec [LSPQ] in Sainte-Anne de Bellevue, Québec; National Centre for Streptococcus [NCS] in Edmonton, Alberta) and Alaska (Arctic Investigations Program [AIP]). The World Health Organization's Collaborating Centre for Reference and Research on Pneumococci at the Statens Serum Institute (SSI) in Copenhagen, Denmark, joined the QC program in 2004. The Iceland Reference Laboratory (IRL) in Reykjavik, Iceland, joined the QC program in 2006, but due to small sample sizes, data from IRL are not included in this report. From 1999 through 2008, 190 isolates were distributed among four laboratories (AIP, NCS, LSPQ, and SSI). The overall serotype concordance was 95.8%, and the overall serogroup concordance was 97.4%. The overall modal MIC concordance for testing by broth microdilution (BMD) and agar dilution was >96% for all the antibiotics except erythromycin (92.1%) and clindamycin (89.5%). MIC comparisons between the Etest and BMD resulted in lower concordance for erythromycin (73.9%), clindamycin (65.5%), and trimethoprim-sulfamethoxazole (80%); however, categorical concordance (susceptible, resistant) remained high at 98.6%, 89.1%, and 90.9%, respectively. Our data demonstrate a high degree of correlation of serotyping and antimicrobial susceptibility testing results between four participating laboratories.

Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager.

The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm ( 25.5 ∘ × 19.1 ∘ FOV ) to 110 mm ( 6.2 ∘ × 4.2 ∘ FOV ) and will acquire data at pixel scales of 148-540 µm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover's mast with a stereo baseline of 24.3 ± 0.1  cm and a toe-in angle of 1.17 ± 0.03 ∘ (per camera). Each camera uses a Kodak KAI-2020 CCD with 1600 × 1200 active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors' Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26 t h and May 9 t h , 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be < 10 % . Image quality, measured via the amplitude of the Modulation Transfer Function (MTF) at Nyquist sampling (0.35 line pairs per pixel), shows MTF Nyquist = 0.26 - 0.50 across all zoom, focus, and filter positions, exceeding the > 0.2 design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11214-021-00795-x.

Variations in color and reflectance on the surface of asteroid (101955) Bennu.

Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu's moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.

Evaluation of the inhibitory and induction potential of YM758, a novel If channel inhibitor, for human P450-mediated metabolism.

This study was designed to examine the in vitro metabolism of YM758, a novel cardiovascular agent, and to evaluate its potential to cause drug interactions and induction of CYP isozymes. After incubation with pooled human liver microsomes, YM758 was converted to two major metabolites (AS2036313-00, and YM-394111 or YM-394112). The formation of AS2036313-00, and YM-394111 or YM-394112 were mediated by CYP2D6 and CYP3A4, respectively, which was elucidated by using a bank of human liver microsomes and recombinant CYP enzymes in combination with the utilization of typical substrates and inhibitors. The Ki values of YM758 for midazolam, nifedipine, and metoprolol metabolism ranged from 59 to 340 microM, being much higher than the YM758 concentration in human plasma. The formation of AS2036313-00, and YM-394111 or YM-394112 was inhibited by quinidine and ketoconazole with Ki values of 140 and 0.24 microM, respectively, which indicates that YM758 metabolism may be affected by coadministration of strong CYP2D6 and 3A4 inhibitors in vivo, given the clinical plasma concentrations of quinidine and ketoconazole. After human hepatocytes were exposed to 10 microM YM758, microsomal activity and mRNA level for CYP1A2 were not induced while those for CYP3A4 were slightly induced. The tested concentration was much higher than that in human plasma, which suggests that the induction potential of YM758 is also negligible.

Tuberculosis in the Circumpolar Region, 2006-2012.

SETTING: The northern circumpolar jurisdictions Canada (Northwest Territories, Nunavik, Nunavut, Yukon), Finland, Greenland, Norway, Russian Federation (Arkhangelsk), Sweden and the United States (Alaska). OBJECTIVE: To describe and compare demographic, clinical and laboratory characteristics, including drug resistance and treatment completion, of tuberculosis (TB) cases in the northern circumpolar populations. DESIGN: Descriptive analysis of all active TB cases reported from 2006 to 2012 for incidence rate (IR), age and sex distribution, sputum smear and diagnostic site characteristics, drug resistance and treatment completion rates. RESULTS: The annual IR of TB disease ranged from a low of 4.3 per 100 000 population in Northern Sweden to a high of 199.5/100 000 in Nunavik, QC, Canada. For all jurisdictions, IR was higher for males than for females. Yukon had the highest proportion of new cases compared with retreatment cases (96.6%). Alaska reported the highest percentage of laboratory-confirmed cases (87.4%). Smear-positive pulmonary cases ranged from 25.8% to 65.2%. Multidrug-resistant cases ranged from 0% (Northern Canada) to 46.3% (Arkhangelsk). Treatment outcome data, available up to 2011, demonstrated >80% treatment completion for four of the 10 jurisdictions. CONCLUSION: TB remains a serious public health issue in the circumpolar regions. Surveillance data contribute toward a better understanding and improved control of TB in the north.

Reinfection after successful eradication of Helicobacter pylori: a 2-year prospective study in Alaska Natives.

BACKGROUND: Limited information exists regarding risk factors for reinfection after cure of Helicobacter pylori infection. AIM: To determine the 2-year reinfection rate of H. pylori in a cohort of urban Alaska Natives. METHODS: Participants over 18 years of age undergoing oesophagogastroduodenoscopy had (13)C urea breath test, culture, CLOtest and histology performed. Those diagnosed with H. pylori who tested urea breath test-negative at 8 weeks after treatment were followed prospectively at 4 months, 6 months, 1 year and 2 years. Subjects experiencing H. pylori reinfection as defined by a positive urea breath test were compared with those who did not become reinfected using univariable and multivariable analysis. Risk of reinfection over time was estimated by the Kaplan-Meier method. RESULTS: Helicobacter pylori reinfection occurred in 14 of 98 subjects successfully treated. The cumulative reinfection rate was 5.1% (95% CI: 0.7%-9.5%) at 4 months, 7.2% (2.0-12.3%) at 6 months, 10.3% (4.2-16.3%) at 1-year and 14.5% (7.5-21.6%) at 2 years. In multivariable analysis, a history of previous peptic ulcer disease or presence of ulcer at time of study oesophagogastroduodenoscopy were the only risk factors associated with reinfection (P = 0.01). CONCLUSIONS: Based on the findings from our study, subjects with a history of or current peptic ulcer disease should be followed, after successful treatment for H. pylori, with periodic urea breath test to detect reinfection, as reinfection would put them at high risk for ulcer recurrence.

Resistance of murine lung tumors to xenobiotic-induced cytotoxicity.

Studies were performed to test the hypothesis that urethane-induced murine lung tumors exhibit xenobiotic resistance and alterations in pulmonary cytochrome P-450 enzymes. 1,1-Dichloroethylene, naphthalene, and paraquat were administered to tumor-bearing and control mice to elicit acute lung cytotoxicity, and responses were evaluated in tumors (papillary and solid), uninvolved surrounding tissue, and untreated control lung. 1,1-Dichloroethylene (125 mg/kg, i.p.) and naphthalene (225 mg/kg, i.p.) caused preferential necrosis of Clara cells in control lungs and uninvolved tissue of tumor-bearing lungs. In contrast, papillary and solid tumors were both resistant to 1,1-dichloroethylene-induced cytotoxicity. Paraquat (10, 20 mg/kg, i.v.) elicited Clara cell damage in control lungs and uninvolved lung tissue of tumor-bearing mice, with minor disruption of the alveolar epithelium. Neither papillary nor solid tumors sustained any apparent cell damage from paraquat. Immunoblots of P-450 enzymes confirmed constitutive expression of CYP2B1 in control lung and uninvolved lung tissue of tumor-bearing mice, but this P-450 enzyme was not detected in either adenomas or carcinomas. Lung CYP1A1 was inducible by beta-naphthoflavone in non-tumor-bearing mice and uninvolved tissue of tumor-bearing mice; however, inducibility was decreased in adenomas and abolished in carcinomas. These results demonstrate resistance of lung tumor cells to chemically induced cytotoxicity and diminished expression of cytochrome P-450 enzymes in tumors.

Pneumococcal endocarditis in Alaska natives. A population-based experience, 1978 through 1990.

BACKGROUND: Streptococcus pneumoniae is an uncommon cause of infective endocarditis (IE). We studied the presentation, microbiologic characteristics, and outcome of nine cases of S pneumoniae IE during a 12 1/2-year period in a population of 75,000 indigenous Alaska Natives (ANs), who have documented high rates of invasive pneumococcal disease. METHODS: Fifty-six cases of IE occurred in ANs statewide during 1978 through 1990. Medical records of all nine confirmed cases of S pneumoniae IE were reviewed. Incidence rates for S pneumoniae IE and all IE were calculated. RESULTS: Alaska Natives experience S pneumoniae IE as a fulminant illness, with acute aortic valve insufficiency (100%) frequently requiring emergent valve replacement, S pneumoniae meningitis (56%), and death (33%). No patient with S pneumoniae IE had known preexisting heart disease, and the most common underlying disease was alcoholism (56%). Pneumonia was diagnosed and embolic complications were suspected in 33%. All five S pneumoniae isolates examined were penicillin sensitive and were of serotypes included in the pneumococcal vaccine. Pneumococcal IE accounted for 15.8% of all IE diagnosed in ANs. Age- and sex-adjusted incidence rates for IE of all causes and S pneumoniae IE were 8.5 and 1.5 per 10(5) persons per year, respectively. During 1986 through 1988, 4.3% of AN adults diagnosed with S pneumoniae bacteremia developed S pneumoniae IE. CONCLUSIONS: Pneumococcal endocarditis in all but one AN case required emergent valve replacement and had a 33% mortality. The annual incidence rate of S pneumoniae IE in this population was five to 37 times higher than contemporary rates elsewhere. Increased efforts to prevent pneumococcal disease in ANs appear warranted. Clinicians everywhere should anticipate the possible development of S pneumoniae IE in adult patients with pneumococcal sepsis, especially with meningitis, even with previous vaccination and prompt adequate antimicrobial therapy.

Protection provided by hepatitis B vaccine in a Yupik Eskimo population. Seven-year results.

The long-term immunogenicity and protection provided by a plasma-derived hepatitis B vaccine (Heptavax B) was determined in a cohort of susceptible persons immunized in 1981. In this study 1581 susceptible persons were immunized with the recommended three-dose regimen of hepatitis B vaccine. After 7 years, 74% of vaccinees retained antibody to hepatitis B surface antigen (anti-HBs) levels of 10 mIU/mL or more. Anti-HBs levels at 7 years varied inversely with age and directly with the level of anti-HBs attained 1 year after the first dose. During the 7 years after the first dose of vaccine, five vaccine responders and three other persons developed antibody to hepatitis B core antigen and their level of anti-HBs increased. None developed detectable hepatitis B surface antigen or clinical hepatitis. This update of an ongoing study continues to suggest that the risk of hepatitis B virus infection to most persons with an initial anti-HBs response to hepatitis B virus vaccine of 10 mIU/mL or greater is low, regardless of the initial antibody level.

Immunogenicity of pneumococcal revaccination in patients with chronic disease.

BACKGROUND: To prevent serious pneumococcal infections, 23-valent pneumococcal polysaccharide vaccine is recommended for individuals over 24 months of age with chronic predisposing diseases and for healthy older adults. This nonrandomized controlled study in rural Alaska assessed the immunogenicity of revaccination in adults. METHODS: Twenty-six adults, 33 to 88 years of age, vaccinated a mean of 7.4 years before this study, were matched to 26 previously unvaccinated subjects by age, number of chronic diseases, sex, and ethnicity. One or more chronic diseases were validated in 62% of subjects (32 of 52). All received a first or second intramuscular dose of pneumococcal vaccine. Antibody levels were determined by radioimmunoassay for 12 pneumococcal capsular serotypes immediately before and 20 to 84 days after vaccination. RESULTS: Six to 9 years after primary vaccination, over one third of serotype-specific antibody levels were below 500 ng of antibody nitrogen per milliliter, equal to the percentage in unvaccinated subjects of similar age. Antibody levels against all pneumococcal serotypes rose to similar levels after primary vaccination and revaccination, and 54% and 55%, respectively, of subjects who received primary vaccination and revaccination had at least a 1.4-fold increase in antibody levels. Only the antibody level for serotype 4 remained low. Neither gender nor age affected peak response. For those with chronic diseases, there was a trend toward fewer low antibody levels against three or more serotypes after revaccination (two subjects [13%]) than after primary vaccination (five subjects [31%]). CONCLUSIONS: Following the initial immunization of high-risk and elderly patients with pneumococcal polysaccharide, pneumococcal antibody levels appear to wane with time. Primary vaccination and revaccination 6 or more years after a first dose of pneumococcal vaccine stimulate comparable mean antibody levels.

Identification of the cytochrome P-450 isozymes responsible for testosterone oxidation in rat lung, kidney, and testis: evidence that cytochrome P-450a (P450IIA1) is the physiologically important testosterone 7 alpha-hydroxylase in rat testis.

Previous studies have shown that several forms of cytochrome P-450 present in rat liver microsomes oxidize testosterone with a high degree of regio- and stereospecificity. The aim of this study was to characterize the pathways of testosterone oxidation catalyzed by rat extrahepatic microsomes. Lung, kidney, testis, prostate, and brain were isolated from 3- and 14-week-old-male Sprague-Dawley rats. Microsomes from lung, kidney, and testis catalyzed distinctly different pathways of testosterone oxidation, whereas microsomes from prostate and brain failed to hydroxylate testosterone directly in a time- and protein-dependent manner. Lung microsomes from immature and mature rats converted testosterone to 16 alpha-hydroxytestosterone, 16 beta-hydroxytestosterone, and androstenedione. Lung microsomes were shown by Western immunoblot to contain cytochrome P-450b (P450IIB1), which has been shown previously to catalyze these three pathways of testosterone oxidation. Antibody against cytochrome P-450b strongly inhibited (greater than 80%) androstenedione formation and completely inhibited (greater than 95%) the 16 alpha- and 16 beta-hydroxylation of testosterone catalyzed by lung microsomes (as did carbon monoxide and antibody against NADPH-cytochrome P-450 reductase). Kidney microsomes from mature male rats converted testosterone to 2 alpha-hydroxytestosterone, 16 alpha-hydroxytestosterone, and androstenedione, whereas only the latter pathway was catalyzed by kidney microsomes from immature rats. Kidney microsomes from mature male rats were shown by Western immunoblot to contain cytochrome P-450h (P450IIC11), which has been shown previously to convert testosterone to 2 alpha-hydroxytestosterone, 16 alpha-hydroxytestosterone, and androstenedione. Antibody against cytochrome P-450h completely inhibited (greater than 95%) the 2 alpha- and 16 alpha-hydroxylation of testosterone by kidney microsomes, but had little effect on androstenedione formation, which is catalyzed by 17 beta-hydroxysteroid dehydrogenase. Testicular microsomes from mature, but not immature, rats catalyzed the 7 alpha-hydroxylation of testosterone. Previous studies have shown that this reaction is catalyzed in liver microsomes by cytochrome P-450a (P450IIA1). Testicular microsomes from mature, but not immature, rats were shown by Western immunoblot to contain cytochrome P-450a. Antibody against cytochrome P-450a or NADPH-cytochrome P-450 reductase completely inhibited (greater than 95%) the 7 alpha-hydroxylation of testosterone by testicular microsomes. A 90:10 atmosphere of carbon monoxide and oxygen did not appreciably block the 7 alpha-hydroxylation of testosterone by testicular microsomes, wh

Comparison of human papillomavirus genotypes in archival cervical cancer specimens from Alaska natives, Greenland natives and Danish Caucasians.

Archival, formalin-fixed, paraffin-embedded cervical cancer specimens from 53 Alaska natives, 32 Greenland natives and 34 Danish Caucasians were analyzed for human papillomavirus (HPV) genotypes 16, 18, 31, 33, 35 and 45 and unidentified genotypes (HPV X) using PCR. The specimens were from the time period 1980-1989. No significant differences were observed in the overall HPV detection rates among cases from Alaska (98.1%), Greenland (84.4%) and Denmark (85.3%). HPV genotype 16 was the most prevalent type: 78.8% in Alaska natives, 96.3% in Greenland natives and 82.8% in Danish Caucasians. A prevalence of 21.2% HPV 31 and 30.8% HPV 33 was found in Alaska natives, of which most were coinfections with HPV 16. Only 3.7% HPV 31 and 3.7% HPV 33 were found in Greenland natives and no HPV 31 and 6.9% HPV 33 were found in Danish Caucasians. HPV 18 was only detected in Alaska natives and HPV 35 and 45 were not detected in any of the three populations. Infections with multiple genotypes were prevalent in Alaskan (36.5%) but not in Greenland natives (3. 7%) and Danish Caucasians (6.9%). The Eskimo subgroup of the Alaska native population has a significantly higher prevalence of HPV genotypes 31 and 33 associated with mixed infections in invasive cancer than the two other native subgroups (P = 0.04) and Greenland and Danish populations, reflecting genotype distributions in dysplasia and normal cervical cytology. The reason for HPV genotype diversity, although unknown, may be relevant to the current development of HPV vaccines.

Elevated concentrations of plasma omega-3 polyunsaturated fatty acids among Alaskan Eskimos.

Eskimos living in rural southwestern Alaska depend on fish and marine mammals as major sources of subsistence food. Fatty acid concentrations in 80 Yupik Eskimos living in either a coastal or river village of southwestern Alaska were compared with those of non-Native control subjects. Concentrations of total plasma omega-3 fatty acids, eicosapentaenoic acid (20:5 omega-3), and docosahexaenoic acid (22:6 omega-3) were 4.3, 13, and 6.8 times higher, respectively, in Native participants than in non-Native control subjects. Concentrations of these fatty acids were higher in coastal-village than in river-village participants; concentrations paralleled consumption of marine mammal oil and marine fish. The ratios of eicosapentaenoic to arachidonic acid for adult coastal- and river-village participants were 1.16 and 0.70, respectively, 14 and 9 times those of non-Native adults, respectively. There was no increase in the mean bleeding times of Native participants of either village.

p53 is not mutated in hepatocellular carcinomas from Alaska Natives.

Hepatocellular carcinoma is common among Alaska Natives. The known risk factor in this population is hepatitis B viral infection; fungal toxins, including aflatoxin B1, have not been detected in foodstuffs. In this series of 14 patients (including 4 siblings and 2 second cousins), 3 patients were less than 12 years old at diagnosis of hepatocellular carcinoma, 8 patients were 13-24 years old, and 3 patients were more than 60 years old. Since p53 mutations occur in 29% of hepatocellular carcinomas worldwide, we tested the tumors for p53 mutations and serum samples for anti-p53 antibodies. Serum samples from these 14 patients did not contain detectable levels of anti-p53 antibodies. Loss of heterozygosity within the p53 locus was not detected in any of 9 informative cases. Immunohistochemical analysis for p53 protein accumulation was negative in all of 11 tumors. DNA sequence analysis of 12 tumor samples showed no evidence of p53 mutation in the highly conserved regions included in exons 5-8. These data, combined with one case from a previous report, indicate a mutation frequency of 0 of 13, which differs significantly from the worldwide frequency of 29% (chi 2 3.9; P = 0.048). These results indicate that liver carcinogenesis among Alaska Natives occurs independently of a traditional p53 pathway. The familial clustering and early onset in this population strongly suggest an inherited genetic predisposition to develop liver cancer. Germline mutations in a tumor suppressor or a cancer susceptibility gene are likely. Future studies of these samples should include investigations of candidate suppressor or susceptibility genes which map to chromosomal regions commonly deleted in liver cancers.

A simple, non-chromatographic procedure to purify immunoglobulins from serum and ascites fluid.

A simple, two-step procedure to purify the immunoglobulin G (IgG) fraction from mammalian sera and ascites fluid is described. In the first step, albumin and other non-IgG proteins are precipitated with caprylic acid (octanoic acid). In the second, the IgG fraction is precipitated with ammonium sulfate. Factors influencing the precipitation of serum proteins by caprylic acid are described, as are procedural modifications to purify the IgG fraction from sera with a high lipid content. The procedure can be used to purify the IgG fraction of serum from rabbit, sheep, goat, horse, rat and mouse, as well as monoclonal antibodies from mouse ascites fluid. Greater than 80% of the IgG in rabbit serum could be isolated by this procedure, with a purity equal to rabbit IgG purified by anion-exchange chromatography. In addition to its simplicity and low cost, the procedure described offers several advantages over other methods to purify IgG.