Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants.

Positron emitters such as (11)C, (13)N and (18)F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is (11)CO(2) since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements.

"Scared Straight" and other juvenile awareness programs for preventing juvenile delinquency.

BACKGROUND: 'Scared Straight' and other programmes involve organised visits to prison by juvenile delinquents or children at risk for criminal behavior. programmes are designed to deter participants from future offending through first-hand observation of prison life and interaction with adult inmates. These programmes remain in use world-wide despite studies and reviews questioning their effectiveness. OBJECTIVES: To assess the effects of programmes comprising organised visits to prisons by juvenile delinquents (officially adjudicated or convicted by a juvenile court) or pre-delinquents (children in trouble but not officially adjudicated as delinquents), aimed at deterring them from criminal activity. SEARCH STRATEGY: Handsearching by the first author in identifying randomised field trials 1945-1993 relevant to criminology was augmented by structured searches of 16 electronic data bases, including the Campbell SPECTR database of trials and the Cochrane CCTR. Experts in the field were consulted and relevant citations were followed up. SELECTION CRITERIA: Studies that tested the effects of any program involving the organised visits of juvenile delinquents or children at-risk for delinquency to penal institutions were included. Studies that included overlapping samples of juvenile and young adults (e.g. ages 14-20) were included. We only considered studies that randomly or quasi-randomly (i.e. alternation) assigned participants to conditions. Each study had to have a no-treatment control condition with at least one outcome measure of "post-visit" criminal behavior. DATA COLLECTION AND ANALYSIS: We report narratively on the nine eligible trials. We conducted one meta-analysis of post-intervention offending rates using official data. Information from other sources (e.g. self-report) was either missing from some studies or critical information was omitted (e.g. standard deviations). We examined the immediate post-treatment effects (i.e. "first-effects") by computing Odds Ratios (OR) for data on proportions of each group re-offending, and assumed both fixed and random effects models in our analyses. MAIN RESULTS: The analysis show the intervention to be more harmful than doing nothing. The program effect, whether assuming a fixed or random effects model, was nearly identical and negative in direction, regardless of the meta-analytic strategy. REVIEWER'S CONCLUSIONS: We conclude that programmes like 'Scared Straight' are likely to have a harmful effect and increase delinquency relative to doing nothing at all to the same youths. Given these results, agencies that permit such programmes must rigorously evaluate them not only to ensure that they are doing what they purport to do (prevent crime) - but at the very least they do not cause more harm than good.

Strontium ranelate inhibits bone resorption while maintaining bone formation in alveolar bone in monkeys (Macaca fascicularis).

Strontium ranelate (S12911) has previously been shown to stimulate bone formation and inhibit bone resorption in rats. To determine whether strontium ranelate affects normal bone remodeling, we studied the effect of strontium ranelate on alveolar bone in monkeys. Strontium ranelate, at dosages of 100, 275, and 750 mg/kg per day, or vehicle, were given by gavage to 31 normal adult monkeys (Macaca fascicularis) (15 males, 16 females), aged 3-4 years. Treatment for 6 months with strontium ranelate resulted in an increase in plasma strontium concentration. Histomorphometric analyses of indices of bone formation and resorption were determined in standardized areas of alveolar bone. Treatment with strontium ranelate decreased the histomorphometric indices of bone resorption (osteoclast surface and number) with a maximal significant effect at the highest dose tested. In contrast to this inhibitory effect on bone resorption, strontium ranelate maintained bone formation. Although the amount of osteoid tended to increase, strontium ranelate, even at the highest dose, had no deleterious effect on bone mineralization, as evaluated by mineral apposition rate and osteoid thickness. These findings show that strontium ranelate decreases indices of bone resorption while maintaining bone formation in the alveolar bone in monkeys.

Graduate survey of the South Carolina Area Health Education Consortium family practice residency programs.

The results of this study demonstrate several interesting characteristics of the graduates of the SC AHEC associated family medicine residency programs: 45 percent practice in South Carolina, 63 percent live further than 120 miles from their residency program, 96 percent are satisfied with their specialty choice, and 56 percent are involved in teaching medical students and residents. Furthermore, these graduates have the following tendencies: to practice in the traditional solo or group practice; to practice in a suburban community, town or rural community and a setting size less than a population of 100,000 persons; to care for the aging adult and geriatric population; to provide nursing home care; and to utilize house calls to provide patient care). As the current health care system continues to be redesigned, this information will be essential for assessment and planning purposes.

The role of linked birth and infant death certificates in maternal and child health epidemiology in the United States.

Linked birth and infant death certificates allow measurement of birthweight-specific infant mortality. Jack Smith, MS, to whom this issue of the American Journal of Preventive Medicine is dedicated, played a key role in the National Infant Mortality Surveillance (NIMS) project. NIMS provided national data on birthweight-specific infant mortality for the 1980 birth cohort, updated data previously collected by the National Center for Health Statistics (NCHS) for the 1960 birth cohort, and supported NCHS's implementation of an annual linked file in 1983. NIMS illustrated themes in infant mortality that remain important: the role of low birthweight (LBW) as a contributor to infant mortality, the contribution of disparities in LBW and birthweight-specific mortality to black-white gaps in infant mortality, and the nation's greater success in reducing mortality among LBW infants than in preventing LBW. Linked birth and infant death records are used nationally and by states to study an array of maternal and infant health topics, from the quality of vital records to the impact of therapeutic and public health interventions. By supplementing birth and infant death records with linkages to program and hospital discharge data, epidemiologists and health service researchers are extending the utility of vital statistics data to monitor maternal and infant health.

The context of HIV/AIDS surveillance.

HIV surveillance and diagnostic testing for HIV infection share elements in common, yet differ notably in context. Clinical testing provides vital information for individual medical and behavioral decisions, whereas surveillance, which focuses on populations, provides information to develop policy, direct resources, and plan services. HIV/AIDS surveillance has evolved over the course of the epidemic, reflecting changes in scientific knowledge, populations affected, and information needs. Likewise, the benefits of early diagnosis of HIV have become increasingly apparent with advances in HIV treatment. This article examines the changing context of HIV/AIDS surveillance and discusses the potential impact of HIV surveillance practices and policies on HIV testing behaviors. Special emphasis is placed on the importance of protecting the confidentiality of HIV/AIDS surveillance data and on the role of health department in monitoring the impact of surveillance policies on test-seeking patterns and behaviors.

Loss of control and the chronic mentally ill in a rural day-treatment center.

PROBLEM: What do chronically mentally ill clients consider to be the core variable in maintaining health, and how do they go about doing this? METHODS: A grounded theory design with analysis of interviews of seven chronically mentally ill clients in a rural day-treatment center. FINDINGS: The core variable in maintaining health according to chronic mentally ill clients is preventing loss of control. A process was discovered that clients used to do this. CONCLUSIONS: Chronic mentally ill clients prevent loss of control by using informal relationships to adapt behaviors, attitudes, and feelings within a supportive environment. If this fails, they turn to formal sources of control such as therapists, case workers, or other mental health providers.

Race/ethnicity misclassification of persons reported with AIDS. The AIDS Mortality Project Group and The Supplement to HIV/AIDS Surveillance Project Group.

OBJECTIVES: To examine differences in race/ethnicity classifications of persons with AIDS among three reporting sources and to estimate the effect of these differences on calculated AIDS rates. METHODS: We reviewed case reports from the national AIDS surveillance database, interview (self-reported) data from 11 state/local health departments, and death certificate information from 16 state/local health departments for agreement in race/ethnicity coding among persons reported with AIDS. RESULTS: Race/ethnicity coding inconsistencies with AIDS case reports were greatest for persons identified as American Indians/Alaska natives on death certificates (46% [47/102] disagreement) and by self-report (57% 8/14 disagreement). Agreement with AIDS case reports was highest either for persons identified as white from death certificates (4% [1314/31,070] disagreement) and white from self-reports (2% [26/1068] disagreement) or black from death certificates (3% [440/13,592] disagreement) and black from self-reports (3% [21/736] disagreement). For other racial/ethnic groups, disagreement with AIDS case reports was intermediate; for Asians/Pacific Islanders, 12% [45/377] disagreement with death certificates and 33% 4/12 disagreement with self-reports; and for Hispanics, 14% [1151/8527] disagreement with death certificates and 24% [59/249] disagreement with self-reports. CONCLUSION: For certain racial/ethnic groups, classification by race/ethnicity can differ substantially by surveillance data source. Because allocation of public health resources may be determined by estimates of disease impact on different population groups, periodic evaluations of the accuracy of race and ethnicity reporting are needed to assure appropriate distribution of these resources.

The supplement to HIV-AIDS Surveillance project: an approach for monitoring HIV risk behaviors.

A variety of surveillance methods are used to characterize the epidemic of HIV infection and AIDS. Such surveillance includes AIDS case reporting, reporting of diagnosed HIV infections, and HIV seroprevalence surveys among targeted sentinel populations. The need for additional surveillance systems to monitor HIV-related risk behaviors has been increasingly evident. One approach to behavioral surveillance, the CDC's Supplement to HIV-AIDS Surveillance project, uses the infrastructure of HIV infection and AIDS case reporting to collect additional information on risk behaviors among HIV-infected persons, who by definition represent those at highest risk.

Future issues in HIV/AIDS surveillance.

Public health surveillance for human immunodeficiency virus (HIV) seeks to define and quantity the spectrum of HIV risk, infection, and disease at the local, state, and national levels. Reporting of cases of acquired immunodeficiency syndrome (AIDS) or HIV and seroepidemiologic surveys are the primary methods. In selected areas, this infrastructure supports supplemental systems that address issues of risk or infection beyond the scope of routine surveillance. Future concerns include maintaining the basic HIV/AIDS surveillance infrastructure, maintaining flexibility to meet emerging needs, improving surveillance for incident infections and risk behaviors, and enhancing the capacity of community-based groups to use surveillance data in setting priorities for prevention and care.

The migration of persons with AIDS: data from 12 states, 1985 to 1992. AIDS Mortality Project Group.

This study measured the migration of persons with the acquired immunodeficiency virus (AIDS) between diagnosis and death using AIDS case and death reports from 12 states for 1985 to 1992. Of 49,805 persons with AIDS, 10.6% changed their place of residence, and half of these individuals who moved changed their state of residence. Migration had relatively little impact on the numbers of persons with AIDS in the largest metropolitan areas, which accounted for approximately 90% of AIDS diagnoses. Although only 3% of deaths occurred in residents of nonmetropolitan areas, the net effect of migration was a 24% increase in the number of persons with AIDS residing in such areas.

Teenagers at risk of human immunodeficiency virus type 1 infection. Results from seroprevalence surveys in the United States.

OBJECTIVE: To describe the seroprevalence of human immunodeficiency virus type 1 (HIV-1) and risk factors for HIV-1 infection among teenagers attending selected clinics. DESIGN: Anonymous, cross-sectional serosurveys conducted in 130 clinics in 24 cities. SETTINGS: Adolescent medicine clinics, sexually transmitted disease clinics, clinics in juvenile detention and correctional facilities, and homeless and runaway youth centers. PATIENTS: Teenagers in whom serum samples were drawn as part of routine medical services. MAIN OUTCOME MEASURES: Prevalence of HIV-1 infection and reported HIV risk behaviors. RESULTS: From January 1, 1990 through December 31, 1992, serum specimens were collected from 79,802 teenagers; 591 of these specimens were positive for HIV-1 antibody. Seropositive test results were found in all 24 cities surveyed, and in 95 (73%) of the 130 clinics surveyed. The median clinic-specific prevalence was 0.2% (range, 0% to 1.4%) in 22 adolescent medicine clinics, 0.3% (range, 0% to 6.8%) in 33 correctional facilities, 0.5% (range, 0% to 3.5%) in 70 sexually transmitted disease clinics, and 1.1% (range, 0% to 4.1%) in five homeless youth centers. Rates exceeded 1% in 37 sites (28%). Excluding sites with many men reporting sex with men, rates in women were similar or somewhat higher than rates in men. Rates were highest among young men reporting sex with men, with clinic rates ranging from 16% to 17% in two homeless youth sites and 13% to 17% in two sexually transmitted disease clinics. Most teenagers with risk information reported heterosexual activity as their only potential risk exposure to HIV-1. CONCLUSIONS: Seroprevalence of HIV was generally low but varied by type of clinic and geographic area. The highest rates were observed among young women and gay men in some settings, suggesting that targeted prevention messages are needed.

HIV-related deaths from selected infectious diseases among persons without AIDS in New Jersey.

This study sought to quantify HIV-related deaths among persons not classified as having AIDS, in an area where AIDS incidence among injecting drug users (IDUs) is high. Death certificates of persons who were aged 25-44 years at death, died in 1987 in two New Jersey counties, and had certain infectious conditions were compared with names in the AIDS Registry. Hospital and/or Medical Examiner records were reviewed for nonmatching cases. Cases were considered as confirmed HIV infection if there was laboratory evidence of such infection and as suggestive HIV infection if the decedent had oral thrush or a combination of certain other clinical findings were present. Of 412 deaths meeting the above criteria, 165 (40.0%) were in the AIDS Registry. We investigated 205 of the remainder; of these, 7.3% were found to have AIDS, 21.5% had confirmed HIV infection without AIDS, and 15.1% had suggestive HIV infection. This increased the HIV-related mortality in excess of deaths due to AIDS in this age group by 9.2% for confirmed HIV infections and 15.6% for both confirmed and suggestive HIV infections, with deaths among IDUs increasing 12.3% for confirmed HIV infections and 18.9% for both confirmed and suggestive HIV infections. Thus, in addition to AIDS indicator diseases, a variety of other infectious conditions can lead to death in HIV-infected persons, particularly in IDUs; however, the extent of such deaths may be less than previously described.

Demographic differences in cumulative incidence rates of transfusion-associated acquired immunodeficiency syndrome.

To describe the demographic patterns of blood transfusion in the United States, the authors analyzed the cumulative incidence rate of transfusion-associated acquired immunodeficiency syndrome (AIDS) (total cases reported from June 1981 through May 1993 per million population) by sex, race/ethnicity, age (at transfusion), and geographic area. Except for a high rate in infants, the rate increased with age, peaking at ages 55-64 years in men and at 65-74 years in women. Overall, the rate in males was 1.7 times that in females. By age, the rate in males was significantly higher than that in females only at ages 0-4 years and 45-84 years, when the rate in males was 2-3 times that in females. Overall, the rates in blacks and Hispanics were twice the rate in non-Hispanic whites. By age, the rates in blacks and Hispanics were significantly higher only at ages 0-4 years and 15-54 years, when they were 2-5 times those in whites, respectively. By state of residence, the incidence of transfusion-associated AIDS was correlated with the rate of all other AIDS cases (Spearman correlation coefficient, 0.83; p = 0.0001). Most of these demographic differences probably reflect differences in exposure to blood transfusion and in the incidence of conditions requiring transfusions.

Socioeconomic differences among people with AIDS: results from a Multistate Surveillance Project.

To characterize the socioeconomic status of persons with acquired immunodeficiency syndrome (AIDS), 11 U.S. state and city health departments interviewed 2,898 persons > or = 18 years of age reported with AIDS between June 1, 1990, and January 31, 1993. Among men who have sex with men, white men reported the lowest percentage (9%), and Central/South American (50%) and Mexican men (40%) reported the highest percentages not completing 12 years of school. Among intravenous drug users (IDUs), 35% of white men, 64% of black men, 67% of Puerto Rican men, 29% of white women, and 63% of black women had not completed 12 years of school. Overall, 77% of the men and 90% of the women were unemployed; we also found racial/ethnic differences by employment but to a lesser degree than differences in education. Among women, but not among men, differences in household income by race and ethnicity were marked; 76% of white and 91% of black female IDUs reported a household income of $10,000. Human immunodeficiency virus (HIV) prevention programs must be targeted toward the educational level of the populations served, and HIV services must adapt to the financial circumstances of their clientele.