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Biomedical subjects

D M Morrison

Publications and source records attributed to D M Morrison.

35 records · Page 2Linked to original sources
PubMed1992

Ethnic differences in family factors related to early drug initiation.

The literature on family predictors of substance use for the general population is reviewed and compared to findings for three specific ethnic groups: black, white and Asian Americans. Rates of substance use initiation are examined in a sample of 919 urban 5th-grade students. Ethnic differences on measures of family predictors are examined and significant ethnic differences are found on several of these factors. Finally, separate regressions for black, white and Asian American youths of family factors on the variety of substances initiated examine ethnic similarities and differences in predictors. The results demonstrate significant differences by ethnicity in family management practices, involvement in family activity, sibling deviance, parental disapproval of children's drinking and family structure. The regression equations identified unique as well as common predictors of the variety of substances initiated by the end of 5th grade. Implications of the results are discussed.

Alcoholism↗
PubMed1992

Race differences in antisocial behaviors and attitudes and early initiation of substance use.

This article examines racial differences in self-reported delinquency, school trouble, antisocial attitudes, and toughness and in teacher-rated aggressive and inattentive behaviors among fifth grade black, white, and Asian American subjects. Also examined are the relationships of these variables to substance initiation within each racial group. Controlling for socio-economic status, racial groups differed from one another in self-reported delinquency, school trouble and toughness, and in teacher-rated aggressiveness and inattention. Antisocial behavior and attitudes were stronger predictors of substance initiation for Asian American than for black and white children. For white children both self-reported and teacher-rated behavior were significantly related to substance initiation. For black children, only self-reported antisocial behavior, and for Asian American children only self-reported delinquent behavior and attitudes predicted substance initiation. Implications for prevention and research are discussed.

Adolescent↗
PubMed1990

Racial differences in acceptability and availability of drugs and early initiation of substance use.

This paper examines differences among three racial groups in exposure to three risk factors for drug use (availability of drugs, acceptability of drug use, and peer alcohol use), and the relationship of these factors to drug use initiation in a sample of preadolescent urban youths. Tobacco and alcohol initiation rates were highest among Whites, lower among Blacks, and lowest among Asian-Americans. Paralleling these differences, White youths reported the greatest access to marijuana, greatest parental tolerance of substance use, and greatest intentions to use drugs as adults. Blacks somewhat less, and Asian-Americans the least. No racial differences appear in the proportion who reported that their peers used alcohol. Marijuana availability and peer use predicted substance initiation for all three racial groups. However, intentions to use substances as an adult and perceived parental tolerance of substance use predicted drug use only for White and Asian-American youths, while the expectation of punishment for drug use predicted lower drug use only among Black youths. Implications for prevention are discussed.

Adolescent↗
PubMed1988

Parents' behavioral norms as predictors of adolescent sexual activity and contraceptive use.

The influence of parental factors on adolescent sexual behavior and contraceptive use has been examined previously, and findings have been contradictory. Previous studies, which found little relationship between parental norms and adolescent sexual activity, have been limited by their failure to recognize developmental differences in the relative weight of parent and peer influences between younger and older teens and by use of selected samples, resulting in a restriction of range. The current study differs in that it utilizes a clustered sample household survey of 329 males and females, aged 14 to 17, and 470 of their parents. Using multiple regression analysis, it was found that parents' reported behavioral norms account for 5% of the variance in whether adolescents have had intercourse, and for 33% of the variance in use of contraception at last intercourse. The study suggests that while parents' normative beliefs have limited effect in the decision to become sexually active, they have considerable impact on later contraceptive use.

Adolescent↗
PubMed1986

Colonic biopsy in verotoxin-induced hemorrhagic colitis and thrombotic thrombocytopenic purpura (TTP).

Sporadic cases and occasional outbreaks of hemorrhagic colitis recently have been associated with the rare Escherichia coli serotype O157:H7, which is now recognized as an important identifiable cause of bloody diarrhea in patients in whom more common gut pathogens cannot be detected. The authors report such a case in a 49-year-old woman who developed thrombotic thrombocytopenic purpura (TTP) and hemorrhagic transverse and descending colitis with a lesion having many of the features of pseudomembranous colitis. While pseudomembrane formation has been described in the hemolytic uremic syndrome (HUS), these features have not, to the authors' knowledge, been described in a patient with hemorrhagic colitis and TTP secondary to a verotoxin-producing serotype of E. coli.

Bacterial Toxins↗
PubMed1984

Papillary cystic tumor of the pancreas.

We studied three cases of papillary cystic tumor of the pancreas and reviewed the literature concerning this uncommon neoplasm. This tumor almost always behaves in a benign fashion and occurs predominantly in young women. The histogenesis remains uncertain, but results of electron microscopic and immunocytochemical studies are consistent with an origin from a primitive cell capable of differentiating along both acinar and endocrine lines.

Adolescent↗
PubMed1983

Predicting contraceptive behavior from attitudes: a comparison of within- versus across-subjects procedures.

Within- versus across-subjects procedures for predicting behavior from attitudes were contrasted. Each procedure requires a comparison among attitudes in order to generate a prediction; the comparison is either among the same attitudes held by different people (across subjects) or among different attitudes held by the same person (within subject). It was hypothesized that the within-subject model provides a more adequate explanation of behavior from attitudinal constructs and, hence, more accurate prediction of behavior from attitudes than does the across-subjects model. To test this view, a sample of 349 married couples was administered a questionnaire containing measures of three attitudinal components--affect, cognition, and conation--toward each of four contraceptive methods--oral contraceptives, IUD, diaphragm, and condoms. Contraceptive behavior was assessed 1 year later. In support of the hypothesis, the within-subject predictions bore a significantly stronger relation to the behavioral criteria than did the across-subjects predictions. This effect was consistent for each of the three components of attitude, for the prediction of behavior and behavioral intention, for male and female respondents, and for a variety of contraceptive behaviors. In addition, both the within- and the across-subjects analyses demonstrated a clear rank ordering in the predictive validity of the three attitudinal components: Conation was a better predictor of behavior than was affect, which, in turn, was better than cognition.

Affect↗
PubMed1980

Ornithine decarboxylase in rat skin: 2. Differential response to hair plucking and a tumor promoter.

Ornithine decarboxylase (OCD; EC 4.1.1.17) activity is induced in dorsal rat skin by either application of the tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate (TPA) or by hair plucking. In TPA-treated rat skin, ODC activity does not rise above controls until 3 hr posttreatment. Following a peak at 4 hr, ODC activity declines until it reaches control levels at 12 hr. In contrast, stimulation of skin by hair plucking causes a 50% decrease in ODC activity by 1 hr. Enzyme activity then increases linearly to a peak at 4 hr and remains at 3 times control levels up to 12 hr. In skin stimulated by both hair plucking and TPA, and peak activity is found to exceed the maximum of either stimulus alone in an additive manner. The response to TPA occurs mainly in the epidermis, while both the epidermis and dermis show a substantial response to hair plucking. Both stimuli cause a lengthening of the half-life of ODC. Stimulation of ODC by hair plucking is insensitive to indomethacin administration but the TPA-response is inhibited 74%. Stimulation of ODC by hair plucking is inhibited by Actinomycin D only if Actinomycin D is given at the time of stimulus administration, and then only partially. The TPA-response is fully inhibited by Actinomycin D if given at the time of TPA application. Inhibition is roughly proportional to the duration of Actinomycin D treatment up to the activity peak at 4 hr. These results indicate that the tumor promoter, TPA, and the more physiological stimulus, hair plucking, stimulate skin ornithine decarboxylase activity by different mechanisms.

Animals↗
PubMed1980

Non-invasive treatment of ununited fractures of the tibia using electrical stimulation.

A non-invasive method of electrical stimulation of healing in ununited fractures of the tibia by pulsed magnetic fileds has been evaluated. In a series of 17 patients all but two of the fractures united within 4 to 10 months, with an average time of just under six months. The method is sufficiently promising to merit further clinical investigation.

Adolescent↗
PubMed1978

Ornithine decarboxylase in rat skin.

Ornithine decarboxylase (ODC; E.C.4.1.1.17) activities can be stimulated 2-10 fold in rat epidermis and dermis by hair plucking. Stimulation does not involve the removal of a soluble ODC inhibitor. ODC activity in the dermis and whole skin decreased with aging, while the epidermis showed little change. The apparent Km for ornithine and the heat stability of ODC in plucked and unplucked skin were similar. ODC was assayed in plucked and unplucked skin of rats fed diets containing between 2 and 24% protein. Activities in both plucked and unplucked skin were higher in the animals fed diets with higher protein contents. ODC levels were positively correlated with the weight changes undergone by rats on controlled-protein diets. In animals restricted to 2% protein diets and rehabilitated with 16% protein diets, enzyme levels were increased after 2 days rehabilitation and peaked after 5 days rehabilitation. The responsiveness of ODC to changes in dietary protein may be useful in the diagnosis of protein malnutrition.

Age Factors↗
PubMedDate not supplied

Psychological distress and substance use by adolescent mothers: associations with parenting attitudes and the quality of mother-child interaction.

This study examines associations between psychological distress and alcohol and drug use across the first five years of raising a child and parenting quality at child age six for 185 adolescent mothers. Overall, alcohol and other drug use in this sample was relatively low, but drug use was associated with more mother-reported unrealistic expectations of child behavior and more attributions of child intent to annoy parent by misbehaving. Maternal psychological distress was associated with maternal reports of negative control (yelling, pushing, spanking, etc.), and alcohol use moderated the association between psychological distress and negative control. At low levels of alcohol use, more maternal distress was associated with greater negative control; at higher levels of alcohol use, maternal distress was not related to negative control, but the absolute level of negative control was similar to that reported by more distressed mothers. Neither psychological distress nor alcohol and other drug use were related to maternal behavior during an interaction task. Overall, much stronger associations with parenting outcomes were found for an index of maternal vocabulary, compared with maternal psychological distress or maternal alcohol and other drug use.

Adolescent↗
PubMedDate not supplied

The effect of low frequency magnetic fields on the healing of the osteotomized rabbit radius.

The object of this experimental work was to evaluate the effect of a noninvasive method of electrical stimulation on the healing of freshly-created osteotomies of the rabbit radius. The apparatus consisted of a solid core electromagnet energized by a square wave unidirectional current. The magnetic field was pulsed transversely across the osteotomy site of the radius while the animal was confined to a restraining device 6 hours daily for 5 days per week. In one group of animals the influence of different pulse frequencies, using 0.1 Hz, 1 Hz, and 4 Hz, was evaluated, while the period of stimulation was kept constant at 2 weeks. In another group of animals, exposure was continued for 3 and 4 weeks while the pulse frequency was kept constant at 1 Hz. Histologic and radiologic comparison with control animals revealed that the initiation of the healing process can be accelerated in magnetic fields pulsed at 1 Hz, but that this effect is not maintained, and that the total period of time required for union is not significantly shortened. In view of these findings, this form of treatment is not recommended for clinical use in the treatment of recent fractures of long bones.

Animals↗