Search PubMed⌕ Search

Biomedical subjects

D M Allen

Publications and source records attributed to D M Allen.

99 records · Page 6Linked to original sources

Family relationships of adults with borderline personality disorder.

Current, ongoing interactions between adults exhibiting borderline personality disorder (BPD) traits and their families of origin may influence and maintain self-destructive behavior. Family interactions in such patients are often characterized by coexisting extremes of overinvolvement and underinvolvement by parental figures. Such parental behavior may trigger preexisting role relationship schemata in vulnerable individuals. Negative family reactions to new behavior patterns may make change difficult. A model for how present-day interpersonal patterns lead to self-destructive behavior, based on clinical observations, is proposed and case examples are presented.

Adult↗

Solar pruning of retinal rods in albino rainbow trout.

Morphology of the central retina and scotopic visual sensitivity were compared in juvenile albino and normally pigmented rainbow trout living under natural and reduced daylight. Outdoor albinos avoided exposing their eyes to direct sunlight, whereas normals were indifferent to it. After 4 months outdoors (approximately 10,000 lux in albinos, approximately 100,000 lux in normals), albinos had severely truncated or missing rod outer segments (ROS) and some missing rod ellipsoids, but normal numbers of photoreceptor nuclei and fully intact cones. Albino estimated ROS volume was only 7.1% of normal in July, but increased to 20% by the following February, mainly via an increase in numbers of ROS. However, in albinos moved indoors October 7 and exposed to 10-30 lux ambient daylight, both the number and length of ROS increased significantly, with estimated ROS volume reaching 95% of normal by 34 days. Albinos generally had more phagosomes (approximately 3 x normal) and more macrophages (approximately 2 x normal) in their outer retina. An optomotor reflex was used to define the effect of ROS volume on the ability to respond visually during dark adaptation. In July, albinos and normals from outdoor raceways (3 months) or indoor raceways (35 days) showed equal sensitivity after first being placed in darkness, but after 1 h in darkness, outdoor albinos with 6% of normal ROS volume were 2.0 log units less sensitive than indoor or outdoor normals, whereas indoor albinos with 53% of normal ROS volume were only 0.7 log units less sensitive. This verifies that most rod cell bodies of albino trout can persist without functional ROS in indirect sunlight, and can regrow functional outer segments in dim daylight. This finding is distinct from the extensive retinal light damage observed in albino rats exposed to more moderate cyclic light, in which entire rod cells degenerate early on.

Albinism, Ocular↗

Sources of ground water salinity on islands using 18O, 2H, and 34S.

Stable isotopes of 18O and 2H in water, and 34S and 18O in dissolved SO4, are used to verify the interpretation of the chemical evolution and proposed sources of salinity for two islands that have undergone postglacial rebound. Results for delta18O and delta34S in dissolved SO4 on the Gulf Islands, southwest British Columbia, Canada, suggest a three-component mixing between (1) atmospheric SO4 derived largely from recharge of meteoric origin, (2) modern marine SO4 associated with either modern-day salt water intrusion or Pleistocene age sea water, and (3) terrestrial SO4. The age of the marine SO4 is uncertain based on the geochemistry and SO4 isotopes alone. Two options for mixing of saline ground waters are proposed--either between current-day marine SO4 and atmospheric SO4, or between older (Pleistocene age) marine SO4 and atmospheric SO4, delta18O and delta2H compositions are relatively consistent between both islands, with a few samples showing evidence of mixing with water that is a hybrid mixture of Fraser River water and ocean water. The isotopic composition of this hybrid water is approximately delta18O = 10 per thousand. delta18O and delta2H values for many saline ground waters plot close to the global meteoric water line, which is distinctly different from the local meteoric water line. This suggests a meteoric origin for ground waters that is different from the current isotopic composition of meteoric waters. It is proposed these waters may be late Pleistocene in age and were recharged when the island was submerged below sea level and prior to rebound at the end of the last glaciation.

British Columbia↗

HIV seroprevalence surveys in drug treatment centers.

Sharing of equipment used to inject illicit drugs intravenously is a risk factor for human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). Systematic surveillance of HIV infection among intravenous drug users (IVDUs) in the United States is essential to monitor the HIV epidemic and to target and evaluate prevention programs for IVDUs and their partners. The most accessible segment of the largely covert population of IVDUs are those in drug treatment programs. In collaboration with State and local health departments and drug abuse treatment agencies, the Centers for Disease Control is conducting blinded (serologic test results not linked to identifiable persons) and nonblinded (in which clients voluntarily agree to participate) surveys of IVDUs entering drug treatment in 39 U.S. metropolitan areas. The same protocol is used in all participating drug treatment centers. Blinded surveys will be carried out annually to determine HIV seroprevalence rates in eligible IVDUs entering drug treatment and to monitor trends over time. Each year, nonblinded surveys of IVDUs entering drug treatment will assess self-reported drug use and sexual behaviors to help design educational interventions and to detect changes in behavior over time. This sentinel surveillance system, using a standardized methodology, will provide the best national and regional data available on the seroprevalence of HIV among IVDUs and the relationships of drug use, sexual behaviors, and HIV serologic status of IVDUs.

AIDS Serodiagnosis↗

Determining HIV seroprevalence among women in women's health clinics.

Human immunodeficiency virus, type 1 (HIV), seroprevalence studies are needed to determine the level and trends of HIV infection among women attending family planning, abortion, and prenatal care clinics in the United States. A review of published and unpublished studies showed that HIV seroprevalence among women attending women's health clinics was 0 to 2.6 percent, although the studies were difficult to compare because of differences in methodology. The Centers for Disease Control, in association with State and local health departments, has developed a standardized protocol to determine HIV seroprevalence among women attending women's health clinics in selected metropolitan areas. Blinded HIV serosurveys (serologic test results not identified with a person) are being conducted annually in selected sentinel clinics in order to obtain estimates of HIV seroprevalence unbiased by self-selection, as well as to monitor trends in infection among clients attending these clinics. In areas with high HIV seroprevalence, nonblinded serosurveys (in which clients voluntarily agree to participate) will be used to assess behaviors that may place women at increased risk of exposure to HIV. Data from the surveys can be used in developing age-specific and culturally appropriate AIDS educational materials, assessing the amount and type of counseling activities required, and evaluating acquired immunodeficiency syndrome (AIDS) prevention activities. The information will provide epidemiologic data to complement the results of other surveys in characterizing the scope of HIV infection among women of childbearing age in the United States.

AIDS Serodiagnosis↗

Mortality in infants discharged from neonatal intensive care units in Georgia.

Although neonatal intensive care units (NICUs) have contributed to advances in neonatal survival, little is known about the epidemiology of deaths that occur after NICU discharge. To determine mortality rates following NICU discharge, we used linked birth, death, and NICU records for infants born to Georgia residents from 1980 through 1982 and who were admitted to NICUs participating in the state's perinatal care network. Infants who died after discharge (n = 120) had a median duration of NICU hospitalization of 20 days (range, 1 to 148 days) and a median birth weight of 1983 g (range, 793 to 5159 g). The postdischarge mortality rate was 22.7 per 1000 NICU discharges. This rate is more than five times the overall postneonatal mortality rate for Georgia from 1980 to 1982. The most common causes of death were congenital heart disease (23%), sudden infant death syndrome (21%), and infection (13%). Demographic characteristics commonly associated with infant mortality were not strongly associated with the mortality following NICU discharge.

Black or African American↗

Regional differences in birth weight-specific infant mortality, United States, 1980.

To describe regional differences in birth weight-specific infant mortality in the United States, we used data from the National Infant Mortality Surveillance project. The infant mortality risk (IMR) for the nation was 11.0 deaths per 1,000 live births. The risk (with 95 percent confidence intervals [CI]) for the four U.S. Census regions were West 9.9 (9.7 to 10.1), Northeast 10.4 (10.1 to 10.6), North Central 10.8 (10.6 to 11.0), and South 12.1 (11.9 to 12.3). In all regions, the IMR for blacks was approximately twice that of whites. Seventy-two percent of the higher IMR in the South was due to a higher proportion of black births compared with the remainder of the nation, reflecting the higher mortality rates suffered by black infants, and 28 percent to higher mortality among southern whites. The IMR for whites in the South was significantly higher than in the remainder of the nation: 9.8 versus 9.1 (relative risk = 1.09, CI = 1.06 to 1.11). Thirty-six percent of this excess in IMR was due to a higher frequency of low birth weight (less than 2,500 grams), 18 percent was due to higher IMR in infants with birth weight less than 2,500 grams, and 46 percent due to higher IMR in infants with birth weights of 2,500 g or more. Black infants born in the West had a lower risk of death than black infants in the other regions. When compared with the Northeast and South, 36 percent of the lower risk in the West among black infants was due to a lower frequency of low birth weight, 38 percent due to lower IMR in infants w'ith birth weight less than 2,500 g, and 26 percent to lower IMR in infants with birth weight of 2,500 g or more.

Birth Weight↗