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Biomedical subjects

A McCormack

Publications and source records attributed to A McCormack.

At least 37 records · Page 2Linked to original sources
PubMed1992

Effect of controlled local release of sodium fluoride on trabecular bone.

Systemic sodium fluoride has been used in the treatment of osteoporosis. Recent studies have shown that it has a positive risk/benefit ratio for use in increasing spinal trabecular bone density. However, thinning of the cortices of the long bones with a resulting increase in fracture incidence has been observed. This study was designed to determine the response of bone to sodium fluoride released from a biodegradable polymer matrix, a technique which could potentially deliver it locally to a site of need in the skeleton which has a positive response to fluoride. In one group of mature New Zealand white rabbits, cylindrical poly(D,L-lactic acid) (PLA) implants, with or without impregnated sodium fluoride, were implanted into the contralateral femoral trochanters and tibial metaphyses. In a second group, similar implants were placed in adjacent vertebrae. Four weeks postimplantation, the femora, tibiae, and vertebrae were removed, sectioned, cleaned of all but mineralized tissue, and the surfaces of the sections stained. The stained surfaces were imaged and analyzed for morphometric properties of the trabeculae. Comparing contralateral vertebrae, those exposed to sodium fluoride had significantly thickened trabeculae, with decreased spacing between them and a greater bone fraction. A similar increase in trabecular width was found in the subchondral bone of the proximal tibiae exposed to local release fluoride. Femoral sections showed no difference, possibly due to the lack of extensive trabecular bone in the region chosen for study.

Animals↗
PubMed1992

Use of a murine T-cell hybridoma expressing human T-cell receptor alpha- and beta-gene products as a tool for the production of human T-cell receptor-specific monoclonal antibodies.

We describe the production of mouse monoclonal antibodies specific for the human TcR using as the immunogen transfected murine T-cell hybridoma cells coexpressing mouse CD3 with human Jurkat TcR alpha and beta chains. The shortage of monoclonal antibodies (mAbs) specific for the human TcR-V alpha and V beta families reflects the difficulties in their production by conventional methods using whole human T cells or purified soluble receptors as immunogens. As an alternative strategy to circumvent these difficulties, we have generated a transfected mouse T-cell line expressing a human (Jurkat) TcR alpha beta dimer in a complex with mouse CD3. The parental mouse T-cell line, TG40, is a cell surface TcR-negative, cytoplasmic CD3-positive variant of the mouse T-cell hybridoma 2B4. The human-TcR alpha beta expressing mouse transfectant was used to immunize mice with the same genetic background as the parent mouse T-cell line, and a human TcR-specific response was successfully achieved. MAb-producing hybridomas were generated by fusing spleen cells from the immunized mice with the mouse myeloma cell line NSO. Of 124 hybridoma supernatants screens, 72 showed reactivity to the human T-cell line Jurkat. Twenty-four of the hybridomas producing human (Jurkat) TcR-specific antibodies were cloned and screened for reactivity to Jurkat TcR. Several IgG2b and IgM mAbs specific for the Jurkat T cell line were selected on the basis of their ability to modulate surface CD3 expression on Jurkat cells. Most of the antibodies do not stain other TcR-expressing human T cell leukemia cell lines, implying specificity for the variable domains of the Jurkat TcR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Analgesic use in home hospice cancer patients.

BACKGROUND: Pain control in hospice patients in the home may be compromised by concerns about overuse of analgesics, particularly narcotics. METHODS: A retrospective chart audit of analgesic type and amount was performed on the medical records of 100 cancer patients receiving hospice care in the home. Different types and amounts of analgesics were converted to a common standard, an oral morphine equivalent (OME) relative to 1 mg of oral morphine sulfate. Descriptive statistics were used to characterize patient analgesic use during the entire course of hospice care and the last 5 days of life. Associations between analgesic use and select patient characteristics (age, sex, cancer site, metastases, and pain intensity at admission) were explored. RESULTS: Ninety-one percent of the sample had used analgesics at some time during hospice care. The proportion of patients using analgesics increased as death approached. The mean and median daily analgesic use over the entire period were 114 and 82 OMEs and during the last 5 days 140 and 84 OMEs, respectively. The range of mean daily analgesic use was between 10 and 735 OMEs. CONCLUSIONS: Individual variability in analgesic use was demonstrated. Not all patients required analgesics, and among those who did there was remarkable variation in the amount used. Large and even enormous doses of analgesics may sometimes be required to control cancer pain.

Aged↗
PubMed1987

Abused to abuser: antecedents of socially deviant behaviors.

The authors interviewed 34 young people who had been sexually abused as children 6 or 8 years after the abuse had occurred and compared them with 34 control subjects who had not been abused. They also compared subjects who had been abused for less than 1 year with those who had been abused for more than 1 year. The findings suggest a link between childhood sexual abuse and later drug abuse, juvenile delinquency, and criminal behavior. The authors explore the effects of pretrauma factors of previous childhood physical abuse and parental modeling of aggression and the postdisclosure factors of social and family blaming.

Adaptation, Psychological↗
PubMed1987

Pathways and cycles of runaways: a model for understanding repetitive runaway behavior.

Based on information provided by 149 runaways staying in a Canadian shelter, the authors developed a model that explains repititious running away as the result of youths' cognitive confusion and unrealistic beliefs. The majority of the youths, who had run away an average of 8.9 times, felt that the events that led them to run away were unpredictable, yet 54 percent blamed only themselves for what happened. The paper describes the pathways, cycles, and outcomes of running away; analyzes the relationship between the youths' experiences with prostitution, delinquency, and sexual and physical abuse and the length of time they had been away from home; summarizes the youths' reasons for running away; compares the beliefs of runaways with and without a history of sexual abuse; and discusses interventions.

Adaptation, Psychological↗
PubMed1987

Histories of sexual abuse in adolescent male runaways.

In this study, data on sexual victimization in the histories of 89 Canadian male runaways as well as information on physical victimization, family structure, family financial stability, delinquent and criminal activities, and reasons for running away from home were evaluated. The population of male runaways evidenced dramatically higher rates of sexual and physical abuse than did randomly sampled populations. Sexually abused and nonsexually abused male runaways shared characteristics noted in the literature as common to runaways: problem families, high rates of delinquency, depression, tension, low self-image, and history of physical abuse. Sexually abused male runaways differed from nonsexually abused runaways in their reactions to their runaway event, with sexually abused male runaways responding in highly avoidant patterns coupled with extreme withdrawal from all types of interpersonal relationships. These differences are explained as consistent with known sequelae of sexual abuse, and the implications for treatment by runaway shelters and for further research are suggested.

Adolescent↗
PubMed1986

Runaway youths and sexual victimization: gender differences in an adolescent runaway population.

Running away from home has often been viewed as one of the sequelae to sexual abuse. Our study of 144 adolescent runaways finds that 38% of male runaways (n = 89) and 73% of female runaways (n = 55) report having been sexually abused. The impact of abuse is examined by studying, within each gender group, its relationship to the subject's perceptions of sexual activity, relationships with peers and adults, involvement with delinquent/criminal activities, and physical and emotional complaints. The results of assessing the differences between abused and nonabused adolescents show that both the victimized males and females are more likely to report anxiety and suicidal feelings than are their nonabused counterparts. Male victims of sexual abuse are more likely to report physical symptomatology and fear of adult men. Female victims of sexual abuse are more likely to be confused about sex and to engage in delinquent/criminal activities. Discussion focuses on gender differences and runaway behaviors in relation to sexual victimization with the suggestion that differences in the degree of abuse and the sex of the abuser may explain study findings.

Adolescent↗
PubMed1985

Risk for alcohol-related accidents in divorced and separated women.

The relationship between marital status and risk for alcohol-related automobile accidents was examined in 10,544 subjects (12% women) who entered 28 driver alcohol education programs over a 6-month period in 1983. Women were more likely than men to be divorced or separated (28 vs 16%). In their marital category, women were younger than men and were more likely to be living alone with their children. The findings implicate the role of lifestyle factors in the development and maintenance of alcohol-related problems, and suggest that women in driver alcohol education programs may require more help than men because they have less social support.

Accidents, Traffic↗