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Biomedical subjects

C L Barrett

Publications and source records attributed to C L Barrett.

16 recordsLinked to original sources

The Minnesota Multiphasic Personality Inventory (MMPI) Hysteria (Hy) scale: scoring bodily concern and psychological denial subscales in chronic back pain patients.

Chronic back pain patients were compared to two nonpain comparison groups on Minnesota Multiphasic Personality Inventory (MMPI) Hysteria (Hy) scores and scores on two Hy subscales: Bodily Concern and Psychological Denial. Pain subjects had significantly higher scores on the Bodily Concern Subscale and lower scores on the Psychological Denial Subscale than nonpain subjects with similar elevated Hy scores. However, pain subjects had Psychological Denial scores similar to those of subjects with normal MMPI profiles, despite significantly higher Hy scores. These findings are interpreted to support the hypothesis that, among pain patients, Hy elevations are partially accounted for by the endorsement of a disproportionate number of Bodily Concern items. Finally, within pain patients, scores on the Bodily Concern subscale were significantly related to more indices of pain duration and severity than were scores on the Psychological Denial subscale. The potential clinical utility of scoring these subscales is discussed.

Adult

Lethal outbreak of hepatitis B in a dental practice.

Between April 1, 1984, and Feb 1, 1985, nine cases of hepatitis B occurred in the patients of a dentist practicing in a rural Indiana county (population, 35,000). This was over 20 times the mean annual incidence for the county in the previous decade. All of the patients had been treated by the dentist two to five months before illness. Although the dentist had never had hepatitis symptoms, his serum was positive for hepatitis B surface antigen and hepatitis B e antigen and negative for anti-hepatitis B core IgM antibody, indicating that he was probably a hepatitis B carrier. Two patients (22%) died of fulminant hepatitis; the case-fatality ratio was over ten times the reported US mean for hepatitis B. Using a case definition based on anti-hepatitis B core IgM antibody positivity and exposure to the dentist during a defined time period, a serosurvey of the dentist's patients identified 15 asymptomatic cases (overall attack rate, 3.2%). Infection risk was related to the amount of trauma involved in the cases' dental procedures. No cause was found for the unusual lethality of the outbreak.

Adult

Serologic evidence for widespread infection with La Crosse and St. Louis encephalitis viruses in the Indiana human population.

The vast under-reporting of La Crosse virus and St. Louis encephalitis virus infections in Indiana residents was evident when numerous inapparent infections were detected retrospectively using serum dilution neutralization analyses of serum obtained in November 1978-April 1979 from 10,208 persons (0.2% of the state's population). An antibody prevalence rate of 3.6% to St. Louis encephalitis virus was detected in the sample population as a whole, with rates as high as 13.2% for residents of individual counties. The estimated average annual rate of infection for the whole population was 0.32%. The antibody prevalence to La Crosse virus in the sample population as a whole was 2.3%, with rates ranging up to 12.5% for residents of individual counties. The estimated average annual rate of infection for the whole population was 0.29%. The epidemiologic behavior of the two viruses was quite different. Age-specific antibody prevalence for St. Louis encephalitis virus indicated a pattern of endemic infection existed in the population as a whole; antibody prevalence rose as the population aged. However, many other infections apparently occurred during the 1975 and earlier epidemics. Age-specific antibody prevalence for La Crosse virus indicated a typical pattern of endemic infection was present. The antibody prevalence to La Crosse virus was best described by the Poisson distribution and that of St. Louis encephalitis virus by the negative binomial distribution. These data support the hypothesis that St. Louis encephalitis virus primarily produces intermittent epidemics in the Midwest while La Crosse virus produces continuous seasonal endemic infections. However, evidence suggestive of a low level of interepidemic St. Louis encephalitis virus infection in the population was also obtained. Computer-drawn synagraphic mapping view "maps" of regional antibody prevalence rates demonstrated the existence of distinct foci of infection for each virus in the human population.

Adolescent

Gilles de la Tourette syndrome: a 20-month study of the effects of stressful life events and haloperidol on symptom frequency.

The frequency of tics in a 10-year-old boy suffering from Gilles de la Tourette syndrome was investigated in the laboratory and at home using counts of tics made by the parents. The study spanned 20 months during which time the patient was treated with haloperidol. Parents' counts were reliable and valid. Stressful life events overcame positive medication effects, and symptom level varied markedly with the activities in which the child engaged. Such situational variability may explain the previously reported waxing and waning of symptoms. Findings also suggested that specific counseling be given when haloperidol is prescribed in order to prepare parents and patients for any apparent worsening of the disorder that may actually be due to the presence of stressful life events.

Activities of Daily Living

Roles of the early genes of bacteriophage T7 in shutoff of host macromolecular synthesis.

Through the use of phage mutants in which various combinations of the early genes are active, and in which late gene expression is blocked, we have examined the roles of each of the five early gene products of bacteriophage T7 in regulating the synthesis of host RNA and proteins. At least two independent transcriptional controls operate during bacteriophage T7 development. The product of gene 0.7, acting alone, leads to a rapid (by 5 min) shutoff of host transcription. In the absence of gene 0.7 function, and in the absence of the phage-specified RNA polymerase, a delayed shutoff of host-dependent transcription begins at approximately 15 min after infection. This secondary control element requires either a functional gene 0.3 or gene 1.1. In the absence of any early gene products, host shutoff is not observed until much later in infection (>30 min). The delayed manner in which the products of genes 0.3 and 1.1 exert their effect suggests that their mode of action is indirect. Under conditions in which the late genes are transcribed (inefficiently) by the host RNA polymerase, gene 1.1 is observed to stimulate the synthesis of lysozyme (the product of a late phage gene). In contrast, when the late genes are transcribed by the phage-specified RNA polymerase (the product of gene 1), the kinetics of synthesis of the phage RNA polymerase itself, and of lysozyme, are not affected by the deletion of genes 0.3, 0.7, 1.1, and 1.3. We conclude that under these conditions, the products of these genes are required neither for regulation of expression of the late genes nor for the shutoff of early phage gene expression.

Bacterial Proteins

Superinfection exclusion by bacteriophage T7.

Only two of the early genes of bacteriophage T7 were found to play a significant role in exclusion of superinfecting bacteriophage T3 particles; genes 0.3 and 1. Protein synthesis by the preinfecting phage particle was not required for efficient exclusion. These findings are discussed with regard to the known functions of these genes during T7 development.

Antibiosis

Risk factors for hepatitis B virus infection among women attending a clinic for sexually transmitted diseases.

Risk factors for and serologic evidence of hepatitis B virus (HBV) infection were analyzed among 557 women. Study subjects were attending a clinic for sexually transmitted diseases and enrolled in a clinical trial of nonoxynol-9 prevention of gonococcal and chlamydial infections. Seventy-eight (14%) showed serologic evidence of past HBV infection. Only age at time of serum collection was significantly associated with HBV marker prevalence (P = 0.04). None of the four measures of sexual activity taken (number of sex partners per month, frequency of sexual intercourse, number of documented episodes of sexually transmitted diseases, and lifetime number of sexual partners) were significantly related to the presence of HBV markers. For each measure, however, differences observed between HBV positive and negative subjects were consistent with what would be expected if these factors did contribute to HBV infection risk. These results support the role of heterosexual transmission of HBV infection in women and are consistent with recommendations for hepatitis B immunization of heterosexually active persons with multiple sexual partners.

Adult

The prediction of chronic pain outcome by psychological variables.

Followup telephone interviews were conducted with fifty-four former patients of a multidisciplinary clinic for the evaluation of chronic pain. Interviews were conducted between thirteen and fifty-five months following initial evaluation at the pain clinic. Followup levels of pain and physical disability were compared with the following measures obtained at initial evaluation: levels of pain and physical disability and scores on the Minnesota Multiphasic Personality Inventory (MMPI), McGill Pain Questionnaire (MPQ), and Zung Depression Inventory (ZDI). In general, both physical disability measures and psychological test scores obtained at initial interview were related to followup measures. However, when the predictive value of initial pain and physical disability was accounted for, psychological test scores tended not to produce further significant increment in predictability. These findings are interpreted to mean that the predictive value of these psychological tests stems less from their reflection of a psychological state or attitude with respect to pain, and more from their tendency to reflect ongoing level of pain, disability, and other pain sequelae. The results support the hypothesis that scores on these psychological tests are, at least in part, a reflection of the actual pain and disability and may not be subject to the same clinical interpretations that scores obtained from a psychiatric sample would be.

Adult