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Biomedical subjects

A R Hollenbeck

Publications and source records attributed to A R Hollenbeck.

11 recordsLinked to original sources

Design and serendipity in establishing a large cohort with wide dietary intake distributions : the National Institutes of Health-American Association of Retired Persons Diet and Health Study.

In 1995-1996, the authors mailed a food frequency questionnaire to 3.5 million American Association of Retired Persons members who were aged 50-69 years and who resided in one of six states or two metropolitan areas with high-quality cancer registries. In establishing a cohort of 567,169 persons (340,148 men and 227,021 women), the authors were fortunate in that a less-than-anticipated baseline response rate (threatening inadequate numbers of respondents in the intake extremes) was offset by both a shifting and a widening of the intake distributions among those who provided satisfactory data. Reported median intakes for the first and fifth intake quintiles, respectively, were 20.4 and 40.1 (men) and 20.1 and 40.0 (women) percent calories from fat, 10.3 and 32.0 (men) and 8.7 and 28.7 (women) g per day of dietary fiber, 3.1 and 11.6 (men) and 2.8 and 11.3 (women) servings per day of fruits and vegetables, and 20.7 and 156.8 (men) and 10.5 and 97.0 (women) g per day of red meat. After 5 years of follow-up, the cohort is expected to yield nearly 4,000 breast cancers, more than 10,000 prostate cancers, more than 4,000 colorectal cancers, and more than 900 pancreatic cancers. The large size and wide intake range of the cohort will provide ample power for examining a number of important diet and cancer hypotheses.

Aged↗

Determinants of adolescent identity development: a cross-sequential study of boarding school boys.

A sociometric measure of identity status was developed based on Marcia's (1966) four ordinal levels of ego identity achievement: Identity Achievement, Moratorium, Foreclosure, and Diffusion. Boarding school adolescent boys (N = 197) rated their dormitory mates on each dimension twice with an interval of six months. Results indicate age differences in identity status for young adolescents, identity development associated with time, and a strong relation between adolescent behavior problems and levels of identity status. Efforts to relate identity status to child-rearing values, social problem-solving, stress, health concerns, and independence were inconclusive.

Adolescent↗

Neonatal preference for visual patterns: modification by prenatal anesthetic exposure?

Exposure to anesthetic drugs during gestation has been shown to cause behavioral changes in rats, and exposure during labor and delivery also affects human neonatal behavior. In this preliminary study, nine neonates who had been exposed to anesthetic agents during gestation were tested for visual-pattern preference. These nine infants looked at the stimuli for statistically significantly longer periods compared with 30 non-exposed infants, and had significantly different preferences for some pairs of patterns. The results suggest that prenatal exposure to anesthetic agents may contribute to behavioral alterations in human neonates.

Adult↗

Children with serious illness: behavioral correlates of separation and isolation.

The deleterious effects of separation have been demonstrated in experimental animal studies and in naturalistic case studies of children. In this study extensive observational and physiological records were obtained on four preschool children who were receiving chemotherapy for childhood cancer. The findings generally parallel those reported in the subhuman primate literature. The children's behavior followed a sequence of agitation followed by behavioral depression. The findings underscore the seriousness of parent-child separation and the need to develop intervention strategies to ameliorate these deleterious effects.

Adaptation, Psychological↗

Infant visual and vocal responses to television.

To provide a first assessment of television influences on infants in the naturalistic setting of the home, visual and vocal behaviors of 72 infants 6 months of age were recorded during 4 days of exposure to various components of broadcast television programs: sound only, picture only, sound plus picture, or a control stimulus of unpatterned sound plus picture. Infants looked longer at the television set during the sound-plus-picture condition than during the picture-only condition, and they looked longer during both of these patterned picture conditions than during both of the other conditions that lacked a patterned picture. Also, infants vocalized more during the picture-only condition than during the sound-only condition. These findings demonstrate that infants attend to the naturalistic presentation of television stimulation and that they respond differentially to the visual and auditory components of television. The results are discussed in terms of the question of the long-term influence on infants' social responsiveness of substantial levels of exposure to the noncontingent, quasi-social stimulation provided by television.

Acoustic Stimulation↗

Anticipated reward and time estimation in young Navajo children.

Time estimations of 1-min. intervals using the method of reproduction by 112 Navajo children were measured under neutral and reward conditions in a repeated-measures design. Anticipated reward (a piece of candy) significantly reduced the accuracy of time estimations. In contrast to previous research the girls were more accurate than the boys; however, the effect of reward was more pronounced for girls than for boys. These data suggest that motivating factors play an important role in the reproduction of time by Navajo children.

Child↗

Behavioral effects of mid-pregnancy administration of lidocaine and mepivacaine in the rat.

Sperm-positive female Long-Evans hooded rats were injected with 6 mg/kg lidocaine (with epinephrine), 6 mg/kg mepivacaine, or saline, into the masseter muscle of the jaw on Day 11 of gestation. Birth, growth, and litter composition were unaffected by the drug treatment, as was shuttle box acquisition. Offspring of drug-treated dams had longer latencies than controls on the first day of negative geotaxis training, and were more sensitive to electric footshock. Lidocaine-dosed offspring responded less in the presence of the correct cue in the visual discrimination task, and mepivacaine-dosed animals were hypoactive in the open field. In a second study, offspring of lidocaine-dosed dams were slower to develop the righting reflex, made more errors in acquiring a water maze, had longer suppression times in a conditioned suppression task, and had longer latencies in the tail flick test. Dosing had no effect upon birth and growth, shuttle box, or footshock sensitivity. These data demonstrate that midgestational exposure to lidocaine or mepivacaine at a dose near the limits of permissible human exposure produces significant behavioral changes in the offspring. This preliminary study suggests that development of some portion of the central nervous system is altered by such exposure. Further work is required to determine the parameters and the extent of the effect.

Animals↗