Prevalence and Mortality of Moose (Alces alces) Infected with Elaeophora schneideri in Montana, USA

Elaeophora schneideri is a filarial nematode of North America that occasionally infects aberrant ruminant hosts such as moose (Alces alces). The role E. schneideri plays in clinical morbidity or mortality of moose remains uncertain. We sampled predominantly hunter-killed adult moose (n=127) to characterize the spatial patterns of prevalence and intensity of worms in carotid arteries of moose in Montana. We compared prevalence and intensity of E. schneideri within these moose to a separate sample of adult moose that died of health-related causes (n=34). We found lower prevalence in northwest Montana (0.06) than in the remainder of the state (0.42). We also found both higher prevalence of E. schneideri and higher intensity to be correlated with increased probability of health-related mortality. Our results suggest presence and intensity of E. schneideri correlate with mortality of moose, although the mechanisms of mortality remain uncertain.

Racial/Ethnic Disparities in Health and Life Insurance Denial Due to Cancer among Cancer Survivors

PURPOSE OF THE STUDY

This study examined racial/ethnic differences in health and life insurance denial due to cancer among cancer survivors after the passage of the Affordable Care Act (ACA).

METHODS

A cross sectional study was conducted using Behavioral Risk Factor Surveillance System data from 2012 through 2020. The dependent variable asked: "Were you ever denied health insurance or life insurance coverage because of your cancer?" Cancer survivors were included if they were diagnosed with cancer after the Affordable Care Act (N=14,815). Descriptive statistics using weighted percentages summarized the results. Logistic regressions provided odds of insurance denial due to cancer across racial/ethnic groups: Non-Hispanic White, Black, and Other/mixed race; and Hispanic. Models adjusted for age, sex, income, and employment status. Interaction terms for age, sex, income, and employment were included in regression models to assess for effect modification.

RESULTS

Weighted chi-squares identified statistically significant differences (p<0.05) between those who were denied or not denied insurance across sex, age, race/ethnicity, income, and employment. Adjusted weighted logistic regressions found significantly higher odds of insurance denial for Blacks (OR:3.01, 95%CI:1.78, 5.08), Other/mixed race (OR:2.10, 95%CI: 1.13, 3.90), and Hispanics (OR:2.16, 95%CI:1.05, 4.46) compared to Non-Hispanic Whites. Sex, income, and employment status were significant effect modifiers. Compared to White women, Black women were significantly more likely to be denied health and life insurance. Compared to Whites with incomes >$25K to <$50K and >$50K to <$75K, Blacks were more likely to be denied insurance (OR:3.50, 95%CI:1.42, 8.66 and OR:7.72, 95%CI: 2.40, 24.81).

CONCLUSIONS

Despite health insurance denial for pre-existing conditions being illegal under the ACA, cancer survivors report racial/ethnic disparities in health and life insurance denial due to their cancer diagnosis. This denial may be particularly harmful for people of color who are already financially vulnerable due to their cancer diagnosis and exacerbate racial/ethnic cancer disparities.

Phylogeography of moose in western North America

Subspecies designations within temperate species’ ranges often reflect populations that were isolated by past continental glaciation, and glacial vicariance is believed to be a primary mechanism behind the diversification of several subspecies of North American cervids. We used genetics and the fossil record to study the phylogeography of three moose subspecies (Alces alces andersoni, A. a. gigas, and A. a. shirasi) in western North America. We sequenced the complete mitochondrial genome (16,341 base pairs; n = 60 moose) and genotyped 13 nuclear microsatellites (n = 253) to evaluate genetic variation among moose samples. We also reviewed the fossil record for detections of all North American cervids to comparatively assess the evidence for the existence of a southern refugial population of moose corresponding to A. a. shirasi during the last glacial maximum of the Pleistocene. Analysis of mtDNA molecular variance did not support distinct clades of moose corresponding to currently recognized subspecies, and mitogenomic haplotype phylogenies did not consistently distinguish individuals according to subspecies groupings. Analysis of population structure using microsatellite loci showed support for two to five clusters of moose, including the consistent distinction of a southern group of moose within the range of A. a. shirasi. We hypothesize that these microsatellite results reflect recent, not deep, divergence and may be confounded by a significant effect of geographic distance on gene flow across the region. Review of the fossil record showed no evidence of moose south of the Wisconsin ice age glaciers ≥ 15,000 years ago. We encourage the integration of our results with complementary analyses of phenotype data, such as morphometrics, originally used to delineate moose subspecies, for further evaluation of subspecies designations for North American moose.

Ethnic Disparities in Gastric Cancer Presentation and Screening Practice in the United States: An Analysis of 1997–2010 SEER-Medicare Data

Describe differences in Helicobacter pylori (H. pylori) screening among a Surveillance, Epidemiology and End Results (SEER)-Medicare elderly population by ethnicity, place of birth, and gastric cancer (GC)-related conditions, as chronic infection with H. pylori is the strongest risk factor for distal GC. Methods: We used the National Cancer Institute's population-based SEER-Medicare cancer database for GC (1997–2010). We extracted demographic, location and disease staging information from the SEER data file, Patient Entitlement and Diagnosis Summary File. We obtained information on frequencies of various GC-related conditions (e.g., peptic ulcer, gastric ulcer, gastritis) and screening (H. pylori testing and endoscopy) from inpatient hospital and physician/outpatient services claims. Results: Data from 34,730 subjects were analyzed. The majority of Asian American/Pacific Islanders (AAPIs), 65.1%, were foreign-born, while majority of Non-Hispanic Whites (NHW), Hispanics and Blacks were US-born (88.7%, 51.3%, and 96.9%, respectively). NHWs were oldest at diagnosis (74.7 y.); Hispanic and Black cases were the youngest (72.4 and 72.9 y., respectively). For NHWs, the most frequently diagnosed GC site was the cardia (36.1%), while for AAPIs, Hispanics and Blacks, the most diagnosed sites were non-cardia (&gt;80%, P &lt; 0.001). Over 55% of NHW, Hispanic and Black cases were diagnosed at regional or distant stage, while 55% of AAPIs were diagnosed at local or regional stage. Over 57% of all cases had a history of GC-related conditions (AAPIs were highest at 64.1%). However, only 11.2% of total cases showed evidence of H. pylori testing. H. pylori testing was more frequent for foreign-born than US-born (2-fold increase in proportions) and AAPIs exhibited the highest proportion of H. pylori testing (22.6% among those with a GC-related condition). Conclusions: Screening for H. pylori was low for all GC cases, despite race/ethnic groups exhibiting conditions for which H. pylori testing is recommended. AAPI GC cases had the highest frequency of H. pylori testing with tumors staged locally or regionally; increased testing could lead to earlier stage of tumor at diagnosis. Future studies should investigate why screening rates are low in patients with GC-related conditions.

Immunosuppressive Effect of 2′-Deoxycoformycin (Pentostatin®) for Rat Islet Allotransplantation

Adenosine deaminase (ADA) is an important enzyme for proper function of lymphocytes and congenital absence of ADA results in a form of severe combined immunodeficiency syndrome. 2′-Deoxycoformycin (Pentostatin®, DCF) irreversibly inhibits ADA and therefore has been suggested as an immunosuppressive drug. The present study evaluated the immunosuppressive effect of DCF for islet allotransplantation in rats. Isolated islets (1,500 islets) from Lewis rats were transplanted into the kidney subcapsular space of streptozotocin-induced diabetic Wistar-Furth rats. DCF was administered IP either as a single injection at 1 mg/kg/wk, 1 mg/kg twice weekly, 5 mg/kg/twice weekly or 1 mg/kg/day, or as a continuous infusion at 0.8 or 1 mg/kg/day. Daily administration of DCF at 0.8 mg/kg in both methods, single daily injection or continuous infusion, resulted in a lymphopenia and a decrease in concanavalin A stimulation of splenic lymphocytes. However, DCF (in all doses) was not effective in preventing islet allograft rejection as evaluated by measuring the duration of normoglycemia following islet transplantation and by microscopic examination of the islet grafts. In fact, the duration of normoglycemia following islet transplantation was 7.5 ± 0.9 and 9.0 ± 1.0 days in rats receiving DCF in single daily injection or continuous infusion, respectively. This was not significantly different from control nontreated transplanted rats (8.5 ± 0.7 days). Increasing the dose of DCF to 1 mg/kg, administered by continuous infusion, resulted in 100% mortality. For comparison, cyclosporine A (20 mg/kg, IP daily injection for 14 days) prolonged islet allograft survival to 27.3 ± 1.5 days (p < 0.001). It is concluded that inhibition of ADA by DCF, despite its marked lymphotoxic effect, does not prevent rejection of islet allograft.

Changes in Rat Adipocyte and Liver Glucose Metabolism Following Repeated Restraint Stress

Rats exposed to repeated restraint weigh less than controls even 8 weeks after stress. Stress-induced weight loss is lean tissue, but the post-stress difference in weight between control and restrained rats is lean and fat mass. Whole-body glucose clearance is enhanced 1 day after stress, but adipocyte glucose utilization is inhibited and muscle glucose transport is unchanged. The studies described here demonstrated that glucose transport was increased in both restrained and pair-fed rats, but that glycogen synthesis was increased only in restrained rats, which may account for the improved whole-body glucose clearance. Adipocyte glucose transport was inhibited and adipose plasma membrane β-adrenergic receptor number was increased 1 day post-stress in restrained rats when weight loss was lean tissue, but were not different from control rats 5 days post-stress, when both fat and lean tissue were reduced. Thus, repeated restraint induces reversible changes in adipocyte metabolism that may represent a transition from the catabolic state of stress to a new energetic equilibrium in rats that maintain a reduced body weight for an extended period of time.

Rangeland responses to pastoralists' grazing management on a Tibetan steppe grassland, Qinghai Province, China

Livestock grazing is the principal land use in arid central Asia, and range degradation is considered a serious problem within much of the high-elevation region of western China termed the Qinghai-Tibetan Plateau (QTP). Rangeland degradation on the QTP is variously attributed to poor livestock management, historical-cultural factors, changing land tenure arrangements or socioeconomic systems, climate change, and damage from small mammals. Few studies have examined currently managed pastures using detailed data capable of isolating fine-scale livestock–vegetation interactions. The aim of the study was to understand how differences among livestock (primarily sheep) management strategies of pastoralists during winter affected subsequent rangeland condition and productivity. Plant species composition, annual herbage mass, and indicators of erosion were quantified during four summers (2009–2012) on winter pastures managed by 11 different pastoralists on QTP steppe rangeland in Qinghai Province, China. Data came from repeated-measurements on 317 systematically located permanent plots, as well as pastoralist interviews and the use of GPS-equipped livestock. Relationships between annual weather variation and herbage mass were modelled using an independent set of vegetation measurements obtained from livestock exclosures. Account was taken of inherent site differences among pastures. Annual variation in herbage mass was found to be best fitted by a model containing a negative function of winter-season temperature and a positive function of spring-season temperature. Accounting for annual and site effects, significant differences among pastoralists were found for most response variables, suggesting that individual heterogeneity among management approaches had consequences, even among neighbouring pastoralists. Annual herbage mass of preferred plant species was positively associated, whereas that of unpreferred species was negatively associated, with mean sheep density and intensity of use. However, the proportion of bare soil, an index of erosion, and annual herbage mass of unpreferred forbs were found to have positive relationships with sheep grazing pressure during the preceding winter, whereas live vegetation cover and annual herbage mass of preferred grasses were negatively related. Thus, on a spatial scale, pastoralists responded adaptively to the cover of preferred plant species while not responding to total annual herbage mass. Pastoralists stocked pastures more heavily, and livestock used regions within pastures more intensively, where preferred species had a higher cover. However, where sheep grazing pressure was high, downward temporal trends in the herbage mass of preferred species were exacerbated. Pastures that were stocked at a lower density did not experience the negative trends seen in those with a higher density.

Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction

Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP). Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae), assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover) with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures, but may not increase annual vegetative production.

Application of the anthropogenic allee effect model to trophy hunting as a conservation tool

Trophy hunting can provide economic incentives to conserve wild species, but it can also involve risk when rare species are hunted. The anthropogenic Allee effect (AAE) is a conceptual model that seeks to explain how rarity may spread the seeds of further endangerment. The AAE model has increasingly been invoked in the context of trophy hunting, increasing concerns that such hunting may undermine rather than enhance conservation efforts. We question the appropriateness of uncritically applying the AAE model to trophy hunting for 4 reasons. First, the AAE assumes an open-access resource, which is a poor characterization of most trophy-hunting programs and obscures the potential for state, communal, or private-property use rights to generate positive incentives for conservation. Second, study results that show the price of hunting increases as the rarity of the animal increases are insufficient to indicate the presence of AAE. Third, AAE ignores the existence of biological and behavioral factors operating in most trophy-hunting contexts that tend to regulate the effect of hunting. We argue that site-specific data, rather than aggregated hunting statistics, are required to demonstrate that patterns of unsustainable exploitation can be well explained by an AAE model. Instead, we suggest that conservation managers seeking to investigate and identify constraints that limit the potential conservation role of trophy hunting, should focus on the critical governance characteristics that shape the potential conservation role of trophy hunting, such as corruption, insecure property rights, and inadequate sharing of benefits with local people.

Design and validation of a multiplex specific primer-directed polymerase chain reaction assay for killer-cell immunoglobulin-like receptor genetic profiling

Current methodologies for the analysis of the killer-cell immunoglobulin-like receptor (KIR) locus utilize specific primer-directed polymerase chain reaction (SSP-PCR), which require a wide range of DNA input, multiple reaction conditions, and up to 16 individual reactions. We have developed and validated a multiplex SSP-PCR method for the genetic analysis of the KIR locus. Design and optimization of four multiplex groups targeting 14 genes and their alleles on the KIR locus has been completed. Each multiplex group contains PCR products that differ in size by a minimum of 15 bp to allow sufficient fragment length resolution for size discrimination by gel electrophoresis. This assay allows for efficient genotyping of the KIR locus while requiring a minimum amount of DNA input, utilizing the simplicity of SSP-PCR.

Impact of a community-based breast cancer screening program on Hopi women

OBJECTIVE

To examine changes in breast cancer knowledge, attitudes, beliefs and behaviors following implementation of a tribal run CDC Breast and Cervical Cancer Program (BCCP), we report 2006 survey results from Hopi women and contrast findings with 1993 survey data and BCCP reports.

METHODS

Community meetings, focus groups, and researchers jointly developed a culturally appropriate survey instrument. Hopi women randomly selected from Tribal enrollment lists were interviewed in-person by Hopi interviewers; 250 women ≥ age 18 participated (87% response) between June and December, 2006.

RESULTS

Among women 40+, 77.5% reported ever having had a mammogram and 68.9% reported having done so within the past 2years, an increase from 45.2% and 46% self-reported in 1993. Compared to 1993, more women in 2006 (88.1% vs. 59%) believed that a mammogram can detect cancer and more than 90% now believe that early detection of cancer can save lives. Women reported a preference (60%) for receiving health care at the Hopi BCCP. Survey results were validated using programmatic data which estimated 76.6% of Hopi women had received mammography screening.

CONCLUSION

Implementation of a tribal run BCCP has resulted in a substantial increase in mammography screening on the Hopi reservation.

The impact of conservation on the status of the world's vertebrates

Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.

Citrus peel use is associated with reduced risk of squamous cell carcinoma of the skin

Limonene has demonstrated efficacy in preclinical models of breast and colon cancers. The principal sources of d-limonene are the oils of orange, grapefruit, and lemon. The present case-control study was designed to determine the usual citrus consumption patterns of an older Southwestern population and to then evaluate how this citrus consumption varied with history of squamous cell carcinoma (SCC) of the skin. In this Arizona population, 64.3% and 74.5% of the respondents reported weekly consumption of citrus fruits and citrus juices, respectively. Orange juice (78.5%), orange (74.3%), and grapefruit (65.3%) were the predominant varieties of citrus consumed. Peel consumption was not uncommon, with 34.7% of all subjects reporting citrus peel use. We found no association between the overall consumption of citrus fruits [odds ratio (OR) = 0.99, 95% confidence interval (CI) = 0.73-1.32] or citrus juices (OR = 0.97, 95% CI = 0.71-1.31) and skin SCC. However, the most striking feature was the protection purported by citrus peel consumption (OR = 0.66, 95% CI = 0.45-0.95). Moreover, there was a dose-response relationship between higher citrus peel in the diet and degree of risk lowering. This is the first study to explore the relationship between citrus peel consumption and human cancers. Our results show that peel consumption, the major source of dietary d-limonene, is not uncommon and may have a potential protective effect in relation to skin SCC. Further studies with large sample sizes are needed to more completely evaluate the interrelationships between peel intake, bioavailability of d-limonene, and other lifestyle factors.

Trends in the incidence of nonmelanoma skin cancers in southeastern Arizona, 1985-1996

This report describes trends in the incidence of various nonmelanoma skin cancers in a region of high ultraviolet exposure. The Southeastern Arizona Skin Cancer Registry routinely identified cases of skin cancer between 1985 and 1996 through pathology logs and reports from dermatology offices and laboratories in 3 Arizona counties. The incidence rates for squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) for non-Hispanic whites were 3 to 6 times higher than the incidence rates from more northern regions. The rates for non-Hispanic whites were approximately 11 times greater than rates for Hispanics. Furthermore, there was no constant increase in the incidence of nonmelanoma skin cancers. The incidence of SCC, in particular, demonstrated a plateau or even a modest decline between 1985 and 1996. Thus the incidence rates of both SCC and BCC in Arizona, although among the highest in the world, do not appear to be increasing as rapidly as predicted elsewhere.

Metabolic responses to leptin in obese db/db mice are strain dependent

Obese, diabetic C57BL/Ks db/db mice that lack the long-form leptin receptor exhibit no decrease in body weight or food intake when treated with leptin. Here we compared responses to leptin in two strains of db/db mice: C57BL/6J mice that are hyperglycemic and hyperinsulinemic and C57BL/Ks that are hyperglycemic and normo- or hypoinsulinemic. Chronic intraperitoneal infusion of 10 microgram leptin/day partially reversed hyperglycemia in C57BL/6J male mice but exaggerated the diabetic state of female mice. Bolus intraperitoneal injections of 40 microgram leptin/day did not effect glucose in either strain of male db/db mice, whereas chronic intraperitoneal infusion of 20 microgram leptin/day significantly reduced fasting blood glucose in male mice from both strains, especially C57BL/6J mice. Food intake, body weight, rectal temperature, and body fat did not change. Chronic intraperitoneal infusion of 10 microgram leptin/day significantly reduced body fat in lean db/+ C57BL/6J but not in C57BL/Ks mice. Thus peripherally administered leptin is active in mice that have only short-form leptin receptors, and the response is dependent on the method of leptin administration and the background strain.

Overexpression of agouti protein and stress responsiveness in mice

Ectopic overexpression of agouti protein, an endogenous antagonist of melanocortin receptors' linked to the beta-actin promoter (BAPa) in mice, produces a phenotype of yellow coat color, Type II diabetes, obesity and increased somatic growth. Spontaneous overexpression of agouti increases stress-induced weight loss. In these experiments, other aspects of stress responsiveness were tested in 12-week-old male wild-type mice and BAPa mice. Two hours of restraint on three consecutive days produced greater increases in corticosterone and post-stress weight loss in BAPa than wild-type mice. In Experiment 2, anxiety-type behavior was measured immediately after 12 min of restraint. This mild stress did not produce many changes indicative of anxiety, but BAPa mice spent more time in the dark side of a light-dark box and less time in the open arms of an elevated plus maze than restrained wild-type mice. In a defensive withdrawal test, grooming was increased by restraint in all mice, but the duration of each event was substantially shorter in BAPa mice, possibly due to direct antagonism of the MC4-R by agouti protein. Thus, BAPa mice showed exaggerated endocrine and energetic responses to restraint stress with small differences in anxiety-type behavior compared with wild-type mice. These results are consistent with observations in other transgenic mice in which the melanocortin system is disrupted, but contrast with reports that acute blockade of central melanocortin receptors inhibits stress-induced hypophagia. Thus, the increased stress responsiveness in BAPa mice may be a developmental compensation for chronic inhibition of melanocortin receptors.

Reproducibility and relative validity of a questionnaire to assess intake of black tea polyphenols in epidemiological studies

Epidemiological studies suggest that tea drinking may reduce the risk of cardiovascular diseases and cancers. Although tea is an important source of antioxidant phytochemicals, variation in preparation techniques may translate to variation in antioxidant capacity. However, most large-scale epidemiological studies use regular food frequency questionnaires to estimate tea intake, and nationally available nutrient analysis databases do not include levels of black tea polyphenols. The Arizona Tea Questionnaire (ATQ) was designed as a tool for collecting more complete dietary tea consumption information, and a database was developed after analyzing 40 black tea samples (brewed, instant, and sun tea) for polyphenols. This study assesses the reliability and relative validity of the ATQ and polyphenol database. Relative validity of estimates of black tea consumption was tested by comparing the ATQ with the traditional Arizona Food Frequency Questionnaire and four days of food records. The ATQ was tested for reproducibility of estimates of black (hot and iced) tea consumption and levels of black tea polyphenol intake. Correlations between two measures of intake taken 2 months apart ranged from 0.72 for black hot tea to 0.86 for black sun tea. Mean intakes (range) of total flavonoids for black tea consumers were 80.8 (3.0-588.0) mg/day at the first ATQ and 102.4 (4.5-802.3) mg/day at the second ATQ (r = 0.83, P < 0.001). The ATQ provided highly reproducible estimates of both total tea consumption and individual tea polyphenol intake. This instrument may be a useful tool in studies of the associations between tea consumption, tea polyphenols intake, and risk for chronic disease.

Fat intake and risk of squamous cell carcinoma of the skin

The varied effects of different classes of dietary fatty acids on carcinogenesis suggest that fatty acid composition is an important determining factor in tumor development. In the present study, we investigated the association between dietary n-3 and n-6 fatty acid intake and risk of squamous cell carcinoma of the skin (SCC). Data were taken from a population-based case-control study of skin SCC in Southeastern Arizona. Our data show a consistent tendency for a lower risk of SCC with higher intakes of n-3 fatty acids [p (for trend) = 0.055]. The adjusted odds ratios for increasing levels of n-3 fatty acids were 0.85 [95% confidence interval (CI) = 0.56-1.27] and 0.71 (95% CI = 0.49-1.00) compared with the lower level as the referent. For the ratio of n-3 to n-6 fatty acids, the odds ratios in successively higher levels were 0.88 (95% CI = 0.59-1.32) and 0.74 (95% CI = 0.51-1.05), suggesting a tendency toward decreased risk of SCC with increased intake of diets with high ratio of n-3 to n-6 fatty acid. More studies are clearly needed to elucidate the function of dietary fatty acids so that recommendations can be made to alter the human diet for cancer prevention, particularly in light of the increasing incidence of SCC of the skin.

Leptin--much more than a satiety signal

Much attention has focused on the effects of leptin as a central satiety agent. There is now a significant amount of evidence that leptin is active in the periphery. This review focuses on the ability of leptin to modify insulin sensitivity, tissue metabolism, stress responses, and reproductive function. Leptin's effect on several of these systems is mediated via the hypothalamic-pituitary axis. Therefore, although in vitro studies provide evidence for direct effects on specific tissues and metabolic pathways, it is essential to consider the interactions between leptin and other regulatory factors in vivo. Little is known about the regulation of peripheral receptor expression or the production of binding proteins. Both of these factors determine the bioactivity of circulating leptin and have the potential to induce a peripheral resistance to leptin, similar to the central "leptin resistance" observed in obese subjects. Future research will clarify which of the endocrine and metabolic actions of peripheral leptin are of physiological relevance and which should be considered a pharmacological manipulation.

Predictors for cutaneous basal- and squamous-cell carcinoma among actinically damaged adults

Risk factors for non-melanoma skin cancer among populations with evidence of precursor damage are not well described. We examined and compared risk factors associated with the development of cutaneous basal-cell (BCC) or squamous-cell (SCC) carcinoma among a group of 918 adults with significant sun damage (> or = 10 clinically assessable actinic keratoses) but no prior history of skin cancer. These adults were participants in a 5-year skin chemoprevention trial between 1985 and 1992, who had been randomized to the placebo group and followed for occurrence of skin cancer. During the study, a total of 129 first SCC and 164 first BCC lesions were diagnosed. The overall BCC and SCC incidence rates for this group of men and women, mean age 61 years, were 4,106 and 3,198 per 100,000 person-years, respectively. Different constitutional and exposure factors were independently associated with BCC compared to SCC. Only increased age independently predicted BCC occurrence among this population. In contrast, older age along with male gender, natural red hair color and adult residence in Arizona for 10 or more years independently predicted SCC occurrence. The substantial incidence of skin cancer found among this population confirms the need for active dermatological monitoring among individuals with multiple visible actinic lesions.

Can Internet-based continuing medical education improve physicians' skin cancer knowledge and skills?

We sought to determine whether an Internet-based continuing medical education (CME) program could improve physician confidence, knowledge, and clinical skills in managing pigmented skin lesions. The CME program provided an interactive, customized learning experience and incorporated well-established guidelines for recognizing malignant melanoma. During a 6-week evaluation period, 354 physicians completed the on-line program as well as a pretest and an identical posttest. Use of the CME program was associated with significant improvements in physician confidence, correct answers to a 10-question knowledge test (52% vs 85% correct), and correct answers to a 15-question clinical skills test (81% vs 90% correct). We found that the overall improvement in clinical skills was due to a marked increase in specificity and a small decrease in sensitivity for evaluating pigmented lesions. User satisfaction was extremely high. This popular and easily distributed online CME program increased physicians' confidence and knowledge of skin cancer. Remaining challenges include improving the program to increase physician sensitivity for evaluating pigmented lesions while preserving the enhanced specificity.

The regulation of total body fat: lessons learned from lipectomy studies

Surgical removal of body fat (partial lipectomy) is a means of directly reducing fat such that metabolic and behavioral responses can be readily attributed to the lipid deficit. If total body fat is regulated, then lipectomy should trigger compensatory increases in nonexcised white adipose tissue (WAT) mass and/or regrowth at excision sites. Many species, including laboratory rats and mice, show lipectomy-induced compensatory recovery of body fat. Those animals exhibiting naturally occurring annual adiposity cycles, such as ground squirrels and hamsters, do so most impressively reaching seasonally appropriate body fat levels indistinguishable from controls. Reparation of the lipid deficit occurs without an increase in food intake, and generally through enlargement of non-excised WAT mass, rather than regrowth of excised WAT. A body fat regulatory system involving humoral and sensory neural inputs to the brain as well as sympathetic neural outputs from brain to adipose tissue is presented. Collectively, the lipectomy model appears useful for testing mechanisms controlling adiposity, or individual depot growth, and offers insight into how lipid stores fluctuate naturally.

A developmental switch affecting growth of fatty rats

Fatty (fa/fa) rats accumulate more adipose mass than their littermates soon after birth, but they first appear obese during the fourth week of life. We analyzed the effects of fa genotype on growth of pups housed with their dams through 4 wk of age. The fa genotype effects on daily gain were undetectable from 7 to 22 days of age but became highly significant (P = 10(-18)) at 23 days of age. When litters were reduced to 4 pups, fa genotype effects on daily gain also became detectable at 23 days of age. The fa genotype effects on daily gain, stomach contents weight, liver weight, and plasma insulin of rats killed from 20 to 24 days of age displayed a marked genotype by age interaction, becoming highly significant at 23 days of age. These changes occur without the environmental changes induced by separating pups from their dams. These observations suggest that a developmental switch triggers hyperphagia and rapidly increases growth rate of fatty rats after 22 days of age.

Functional analysis of human ornithine decarboxylase alleles

It has been known for > 10 years that there are two alleles of the human ornithine decarboxylase (ODC) gene, defined by a polymorphic PstI RFLP in intron 1. We have sequenced a large portion of each of the two alleles, including some of the 5' promoter region, exon 1, intron 1, and exon 2, and determined that a single nucleotide polymorphism at base +317 (relative to transcription start site) is responsible for the presence or absence of the PstI restriction site. We have developed two genotyping assays, a PCR-RFLP assay and a high-throughput TaqMan-based method, and determined the ODC genotype distribution in >900 North American DNA samples. On the basis of its location between two closely spaced Myc/Max binding sites (E-boxes), we speculated that the single nucleotide polymorphism at base +317 could have functional significance. Results of transfection assays with allele-specific reporter constructs support this hypothesis. The promoter/regulatory region derived from the minor ODC allele (A allele) was more effective in driving luciferase expression in these assays than the identical region from the major allele (G allele). Our results suggest that individuals homozygous for the A allele may be capable of greater ODC expression after environmental exposures, especially those that up-regulate c-MYC expression.

Older adults need guidance to meet nutritional recommendations

OBJECTIVE

The purpose of this study was to compare the diet of healthy, free-living senior volunteers to the dietary reference intakes (DRIs) and Food Guide Pyramid recommendations.

METHODS

This study was a cross-sectional assessment of dietary habits, as measured using a standardized food frequency questionnaire, among 1,740 healthy Southwestern U.S. adults, aged 51 to 85 years. Assessment of independently-living volunteers to chemoprevention trials provides an efficient mechanism to profile typical dietary habits among the older adult population.

RESULTS

Daily estimated macronutrient intakes exceeded recommended proportions of protein and fat. In contrast, more than 60% of this senior population reported dietary vitamin D, vitamin E, folate and calcium intakes below estimated average requirements (EAR). Based on the Food Guide Pyramid recommendations, fewer than 10% of the older adults consumed the recommended daily dairy and grain servings. More females than males consumed recommended vegetable (49% versus 40%) and fruit (53% versus 48%) servings (p < 0.05). More males consumed recommended grain (11% versus 7%) and protein (78% versus 73%) servings (p < 0.05) than females.

CONCLUSIONS

Mean micronutrient intakes compared well with DRIs, although fewer than one-half of these older adults consumed recommended levels for vitamin D, vitamin E, folate, and calcium or daily food servings of dairy, grains, vegetables or fruits. Since the beneficial aspects of foods are not limited to essential nutrients, nutrition recommendations to older adults may be improved by emphasizing daily servings of nutrient-dense choices within the Food Pyramid.

Identification of urocortin mRNA antisense transcripts in rat tissue

Urocortin (UCN) has 45% sequence homology with corticotropin releasing factor (CRF) and binds to CRF receptors. We used reverse-transcriptase-polymerase chain reaction to demonstrate the presence of UCN RNA in various brain regions and in peripheral tissues. Ribonuclease protection assay (RPA) using sense and antisense riboprobes demonstrated the presence of a naturally occurring antisense UCN RNA transcript in a number of tissues. Northern blot indicated that the antisense transcript was the same size as sense UCN. RPA, using probes that covered bases 1 to 560 of 579 bp sequence of rat UCN, indicated that the antisense sequence was complementary to sense UCN but did not contain an open reading frame. Sense and antisense UCN RNA were co-expressed in all tissues that contained levels of either transcript detectable by RPA. Sense RNA expression was greater than antisense in the midbrain, the two transcripts were expressed equally in the hypothalamus and antisense was expressed at higher levels than sense in the liver, heart, and skeletal muscle. Antisense RNA expression was stress responsive, suggesting that it may play a role in regulating transcription or translation of UCN mRNA.

Residues F16-G33 and A784-N823 within platelet thrombospondin-1 play a major role in binding human neutrophils: evaluation by two novel binding assays

The thrombospondin-1 (TSP1) structural requirements within its heparin-binding domain (HBD)(30 kd) or within the other domains of the molecule (450 kd) that interact with neutrophils (PMNs) have not been delineated. Synthetic peptides based on the HBD, a TSP1 proteolytic fragment lacking the HBD, a large C-terminal domain of TSP1 (210 kd), a TSP1 recombinant fragment (rTSP1(784-932)), and a monoclonal antibody directed against the TSP1 type 3 repeats (mAb D4.6) were utilized to map such structural requirements on TSP1. Synthetic peptides containing a heparin-binding motif and encompassing residues F16-G33 or A74-S95 of TSP1 competed quantitatively with iodine 125-labeled TSP1 for binding to heparinagarose beads. However, only F16-G33 was a competitor of TSP1 binding to PMNs, suggesting that the sequence F16-G33 within the HBD plays a role in PMN binding. The interaction site within the 450-kd fragment was further narrowed. A TSP1 -derived proteolytic fragment (210 kd), a recombinant TSP1 fragment (rTSP1(784-932)), and a type 3 repeat anti-TSP1 monoclonal antibody (mAb D4.6) competed for the binding of 125I-labeled TSP1 to PMNs. The N-terminal of rTSP1(784-932) and C-terminal sequence analysis of TSP1-210 kd delineated the structural requirements for the second binding region for PMNs-namely, residues A784-N823.

Tea intake and squamous cell carcinoma of the skin: influence of type of tea beverages

Differences in tea drinking habits are likely to vary by populations and could contribute to the inconsistencies found between studies comparing tea consumption and cancer risk. A population-based case-control study was used to evaluate how usual tea consumption patterns of an older population (n = 450) varied with history of squamous cell carcinoma (SCC) of the skin. A detailed tea questionnaire was developed to assess specific tea preparation methods and patterns of drinking. In this southwestern United States population, black tea was the predominant variety of tea consumed. We found no association between the broad definition of any tea consumption and skin SCC. However, the adjusted odds ratios (ORs) for hot and iced black tea intake were 0.63 [95% confidence interval (CI), 0.36-1.10] and 1.02 (95% CI, 0.64-1.63), respectively. Controls were more likely to report usually drinking strong hot tea (OR, 0.74; 95% CI, 0.53-1.03) with increased brewing time (P for trend = 0.03). Adjusting for brewing time, the association between skin SCC and hot black tea consumption suggests a significantly lower risk in consumers of hot tea compared to nonconsumers (OR, 0.33; 95% CI, 0.12-0.87). This is one of the first studies to explore the relation between different types of tea consumption and occurrence of human cancers. Our results show that tea concentration (strength), brewing time, and beverage temperature have major influences on the potential protective effects of hot black tea in relation to skin SCC. Further studies with increased sample sizes are needed to evaluate the interrelationships between preparation techniques, tea type, and other life-style factors.