Funding trends in hormetic research.

The topic of hormesis research funding has been a focus of deliberation within the scientific community for several decades. A common assumption/belief is that most hormesis research is funded by the private sector. With this assumption may emerge questions revolving around potential bias of such research. To provide some clarification to this issue, all hormesis research articles were obtained through online databases for 5-year increments starting with 1995 and ending with 2015 and were subsequently categorized by their funding source. A total of 710 articles were found for those years and 383 of those reported information on funding sources. Reporting funding is not required by law and until more recently was not encouraged or required by funders, research institutions, and/or scientific publishers. The analysis revealed that the assumption that the majority of hormesis research has been privately funded was not supported, with the public sector (i.e. federal and state governmental agencies) exclusively contributing to 78% of the reported research funding. Going forward, funding transparency for scientific research as a whole is essential within the scientific community as it may affect how research may be perceived, accepted, and applied.

Statewide survey of laboratories performing Mycobacterium tuberculosis testing in Minnesota.

Rapid and accurate laboratory detection and identification of Mycobacterium tuberculosis, particularly multidrug-resistant strains, is critical to both public health control measures and patient management. The authors surveyed microbiology laboratories to evaluate whether their methods met national guidelines. As needed, laboratories received individualized recommendations for improvement. The laboratories were resurveyed a year later to assess changes in methods. Current guidelines recommend fluorochrome acid-fast smears, broth cultures, identification by nucleic acid probe or BACTEC-NAP, and BACTEC primary susceptibility panels, which should include pyrazinamide. Of 27 laboratories performing acid-fast smears, 15 used fluorochrome methods. Six of 16 laboratories performing mycobacterial cultures used broth media. Of six laboratories performing species identification, five used nucleic acid probes or BACTEC-NAP. Of five laboratories evaluating drug sensitivity, two used BACTEC and two included pyrazinamide in their protocols. Overall, 24 (89%) laboratories needed improvements; a year later, 16 (67%) of those had altered their methods or made definite plans to do so. Survey results suggest that health departments can facilitate improvements in laboratory testing for pathogens of public health importance.

The role of contextual cues in operant responding in rats.

Following lever-press training on a variable-interval 60-second schedule of food presentation, groups of rats either remained in their home cages or were exposed to the operant chamber, from which lever and food had been removed, for five sessions. The lever was replaced in the chamber and rats from Group 1 (exposure to chamber) and Group 3 (home cage) were returned to the variable-interval schedule. Although response rates in test sessions were somewhat lower than at the end of training, there was no statistically significant difference in rates for either group. Rats in Group 2 (exposure to chamber) and Group 4 (home cage) received two test sessions of extinction. During the first session, Group 2 rates of lever pressing were significantly higher than Group 4 rates. These findings do not support the view that associations between contextual cues and the reinforcer serve to energize instrumental behavior (Pearce & Hall, 1979), and provide only minimal support for the view that contextual cues control responses that compete with the operant (Mills, 1980).

Attention in the pigeon: testing for excitatory and inhibitory control by the weak elements.

In two experiments, pigeons were trained on a successive discrimination between a color and either a compound S+ or a compound S- consisting of a form superimposed on a second color. Two stimulus control tests followed discrimination training: an attention test in which the form and colors used in training were presented singly and in combination, and then a resistance-to-reinforcement test using the form element of S+ or S- and a novel form. In the attention test, the birds trained with a compound S+ responded most to the S+ compound, less to the S+ color alone, and still less to the S+ form on a dark key. Few responses were made to the negative stimulus, either alone or with the S+ form added. The birds trained with a compound S- pecked most at the S+ color and to a compound of the S+ color with the S- form added. The resistance-to-reinforcement test showed that the birds trained with a compound S+ responded more to the S+ form than to a novel form. However, the birds trained with a compound S- did not reliably respond more to a novel form than to the S- form. These findings suggested that the form element of a compound S+ gains some excitatory control, but the form element of a compound S- does not acquire inhibitory control. The possibility existed that low levels of responding to the S+ form on a dark background in the first experiment were due to use of a darkened key to separate S+ and S- periods during discrimination training. However, the essential findings were the same in a second experiment in which darkening of the chamber separated S+ and S- periods.

Influence of herbicide tolerant soybean production systems on insect pest populations and pest-induced crop damage.

Conventional soybean weed management and transgenic herbicide-tolerant management were examined to assess their effects on soybean insect pest populations in south Georgia in 1997 and 1998. Soybean variety had very little impact on the insect species observed, except that maturity group effects were observed for stink bug, primarily Nezara viridula (L.), population densities on some sampling dates. Stink bugs were more abundant on the early maturing varieties in mid-season. Velvetbean caterpillar, Anticarsia gemmatalis Hübner, potato leafhopper, Empoasca fabae (Harris), and grasshoppers Melanoplus spp. were more numerous on either conventional or herbicide-tolerant varieties on certain dates, although these differences were not consistent throughout the season. Soybean looper, Pseudoplusia includens (Walker), threecornered alfalfa hopper, Spissistilus festinus (Say), and whitefringed beetles, Graphognathus spp , demonstrated no varietal preference in this study. Few weed treatment differences were observed, but if present on certain sampling dates, then pest numbers were higher in plots where weeds were reduced (either postemergence herbicides or preplant herbicide plus postemergence herbicide). The exception to this weed treatment effect was grasshoppers, which were more numerous in weedy plots when differences were present. In post emergence herbicide plots, there were no differences in insect pest densities between the conventional herbicides (e.g., Classic, Select, Cobra, and Storm) compared with specific gene-inserted herbicide-tolerant materials (i.e., Roundup and Liberty). Defoliation, primarily by velvetbean caterpillar, was different between soybean varieties at some test sites but not different between herbicide treatments. We did not observe differences in seasonal abundance of arthropod pests between conventional and transgenic herbicide-tolerant soybean.

Regulatory consideration in radiation protection.

A regulatory scheme is suggested that identifies regions labeled "unacceptable" and "safe" as the upper and lower bounds and "operational" region is identified as the continuum between the two extremes. These regions are associated with levels of annual risk of cancer death for a given level of lifetime exposure between 100 mrem/yr and 1 mrem/yr, upper and lower bounds, respectively. Concern is expressed with establishing public health standards at ALARA (as low as reasonably achievable) levels, which result in lower standards for reference, and views are presented on several issues of interest in regulations for protection of the public from radioactivity in drinking water. Based on the regulatory scheme suggested, the author concludes that existing standards for drinking water appear to be lower than necessary.

Assessing the risks of Rn exposure: the influence of cigarette smoking.

The principal hazard associated with exposure to Rn progeny is lung cancer. However, most lung cancer is caused by smoking, which raises a dual problem of deriving Rn-progeny cancer risk estimates from miner populations who, in large part, are smokers and applying these estimates to the general population whose lung cancer risk, in large part, is determined by smoking habits. We examine current risk estimates for Rn-progeny-induced lung cancer using a cohort life table methodology. Estimates of lifetime probability of dying of lung cancer, average loss in life expectancy due to premature lung cancer death, and loss in life expectancy per premature lung cancer death are calculated for the general population for 1969 and 1978, nonsmokers, and smokers. These calculations demonstrate that such risk estimates are affected by smoking, and by trends in smoking habits, in several ways. Major smoking-related factors in this interaction are the proportion of smokers in the mining population used to derive lung cancer risk estimates, the proportion of smokers in the "general" population, and the assumed interaction (additive or multiplicative) between lung cancer risk, Rn-progeny exposure, and smoking history. At this time the data are not sufficient to recommend one particular modeling approach. However, our evaluation demonstrates that broad statements about Rn-progeny lung cancer risk such as "x cancers/10(6) person working level month," while informative, are incomplete without further specification. Any risk assessment must clearly state the population assumed to be at risk and the risk model assumed to be operating. Finally, the caveats appropriate to these assumptions should also be enunciated.

Screening for tuberculosis infection among secondary school students in Minneapolis-St. Paul: policy implications.

Three students in the St. Paul Public Schools were diagnosed with active tuberculosis (TB) in late 1991 and early 1992. To define the prevalence of TB infection in St. Paul and Minneapolis, we conducted school-based screening projects in the St. Paul and Minneapolis public schools during 1992 and 1993. In St. Paul, 7,596 (74.8%) students in grades six through 12 received Mantoux tests; 268 (3.5%) were reactive. Infection rates varied significantly by country of birth, with students born outside the United States more likely to be Mantoux reactors than U.S.-born students (RR = 20.2; 95% CI = 14.9-27.3; p < 0.001). In Minneapolis, 752 (47.2%) eighth-grade students received Mantoux tests; 23 (3.1%) were reactive. As in St. Paul, infection rates varied by country of birth; students born outside the United States were more likely to have reactive Mantoux tests than students born in this country (RR = 13.2; 95% CI = 5.6-31.4; p < 0.001). We conclude that routine TB screening of school students is not warranted in Minnesota, although school-based screening targeted at the highest risk students, particularly those born outside the United States, may be a beneficial prevention strategy.

A time-limited treatment program for children and their families.

In December 1972 the family psychiatric unit opened at Royal Jubilee Hospital in Victoria for the treatment of children under age 15 with emotional disturbances or behavior problems. Each child is admitted to the unit on a predetermined date for a pre-established period of five weeks, during which time the child's family is also involved in treatment. After the child is released from the unit, therapy continues for an additional five weeks in the family's home and then contact is terminated. To date more than 350 children have been admitted to the unit; a second admission has been required in only 21 cases.

Attitudes and practices regarding varicella vaccination among physicians in Minnesota: implications for public health and provider education.

OBJECTIVES: This study sought to determine physicians' attitudes and practices regarding varicella vaccine. METHODS: A sample of Minnesota family physicians and pediatricians was surveyed in January 1997. RESULTS: Of 255 physicians surveyed, 108 (42%) reported routinely offering varicella vaccine. Physicians who perceived their professional organization's recommendations as "very important" were more likely to routinely offer varicella vaccine. Physicians who preferred natural disease over vaccination and those concerned about waning immunity were less likely to routinely offer vaccine. CONCLUSIONS: Recommendations of professional organizations have encouraged varicella vaccine use and may further enhance future use. Differences in pediatricians' and family physicians' attitudes and practices regarding this vaccine suggest that education of providers by specialty may be needed to increase acceptance of newly licensed vaccines.

Physicians' practices and opinions regarding prenatal screening for human immunodeficiency virus and other sexually transmitted diseases.

BACKGROUND AND OBJECTIVES: Early prenatal diagnosis of sexually transmitted diseases (STDs), particularly human immunodeficiency virus (HIV), is critical for maternal and infant health. We conducted a survey to assess physicians' prenatal STD screening practices and opinions. STUDY DESIGN: A random sample of obstetricians and family physicians was selected from the Minnesota Medical Association directory to complete a standardized telephone survey. RESULTS: Eighty-three (86%) of 96 eligible obstetricians and 94 (95%) of 99 eligible family physicians completed the survey. Nearly all physicians recommend universal prenatal screening for syphilis (97%) and hepatitis B (99%); fewer physicians recommend prenatal screening for HIV (43%), chlamydia (26%), and gonorrhea (24%). Adjusting for physicians' specialty, female physicians were more likely than male physicians to recommend universal prenatal HIV screening (odds ratio [OR] = 2.1; 95% confidence interval [CI] = 1.1-4.2). Adjusting for physicians' ages, physicians with more than 20% uninsured/Medical Assistance patients were more likely than other physicians to recommend prenatal gonorrhea screening (OR = 3.1; 95% CI = 1.4-6.8); similar factors were associated with chlamydia screening. Although 89% of physicians supported universal prenatal HIV counseling and voluntary screening, the median percentage of prenatal patients screened for HIV was only 10%. CONCLUSIONS: Most physicians reported routinely screening prenatal patients for syphilis and hepatitis B. Although many physicians agreed with recommendations for universal prenatal HIV screening, their reported screening practices varied considerably from this approach.

Estimate of risk from environmental exposure to radon-222 and its decay products.

Consideration of the epidemiological evidence on radiogenic lung cancer in uranium miners and of the incidence of the disease generally leads to an upper estimate for the lifetime risk of 10(-4) cases per working level month for members of the general population.

Evaluation of clinical and laboratory aspects of antibody tests for detection of hepatitis C virus infection in blood donors and recipients from a low-risk population.

BACKGROUND: When the first-generation enzyme immunoassay (EIA) for detection of antibody to hepatitis C virus (anti-HCV) was approved in May 1990, blood banking agencies recommended testing of all components in inventory. In many cases, one or more components from these units had already been transfused. STUDY DESIGN AND METHODS: Donors that reacted in first-generation EIAs and recipients of their components were identified, and anti-HCV test methods (including first-generation EIA, second-generation EIA, and recombinant immunoblot assay [RIBA]) were evaluated. RESULTS: Of 66 donors identified as anti-HCV-positive by first-generation EIA, 17 were positive in second-generation EIA. Of these 17, 9 reacted in RIBA; 6 of these showed evidence of HCV infection in polymerase chain reaction (4) and/or probable transmission of HCV to a transfusion recipient (3). Of the 48 specimens that were positive in first-generation EIA and negative in second-generation EIA, only 1 was positive in RIBA; serum was not available for polymerase chain reaction testing, and there were no living transfusion recipients in whom to assess evidence of transmission of HCV. CONCLUSION: This study documents the low predictive value of EIAs for anti-HCV in a low-prevalence blood donor population and emphasizes the need for additional testing to confirm the specificity of samples that react in the screening tests.