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Biomedical subjects

W J Callahan

Publications and source records attributed to W J Callahan.

11 recordsLinked to original sources
PubMed2001

Sodium chloride enhances the storage and conformational stability of BDNF and PEG-BDNF.

PURPOSE: BDNF, a noncovalent homodimer, was modified by covalently attaching polyethylene glycol (PEG) with an average molecular weight of 20kDa to the N-terminal methionine. Stability of modified BDNF (PEG-BDNF) in aqueous solution was compared to BDNF after storage at elevated temperature in the presence and absence of NaCl. METHODS: SDS-PAGE. Light Scattering and Size Exclusion Chromatography were used to assess conformational stability and chemical degradation. In addition, CD spectroscopy was used to follow changes in secondary and tertiary structures upon thermal stress of the protein. RESULTS: NaCl containing formulations are more stable than NaCl-free formulations. In NaCl-free formulations, the main degradation product of BDNF and PEG-BDNF had a molecular weight of monomer that was more chemically degraded than the dimer. Additionally, the degradation of PEG-BDNF occurred at an accelerated rate compared to BDNF in NaCl-free environments. CONCLUSIONS: The addition of NaCl to formulations enhances the shelf-life and conformational stability of both BDNF and PEG-BDNF.

Brain-Derived Neurotrophic Factor↗
PubMed2000

Assessing bilingual and monolingual Latino students with translations of the MMPI-2: initial data.

This article presents the results of 2 studies conducted with Spanish versions of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) with Latino students. Study 1 compared the results of 2 administrations of the MMPI-2, one in English and the other in Spanish. Study 2 compared the results of administrations of 2 Spanish versions of the MMPI-2, the official Mexican adaptation and the Version Hispana. In both cases, scale score differences were not found. Comparability, as operationally defined by test-retest reliability, was found to be higher for the group that was administered the English and Spanish versions than the group administered the 2 Spanish versions. Overall, the results were found to suggest correspondence. Yet, the authors warn against concluding "perfect" correspondence because other key groups need to be studied, including psychiatric patients and persons from the Latino community. Also, the determination of linguistic equivalence needs further refinement.

Adult↗
PubMed1996

MMPI performance of central American refugees and Mexican immigrants.

This study compared the MMPI scores of Central American refugees from Guatemala and El Salvador to those of Mexican immigrants. It was expected that subjects from Guatemala and El Salvador would obtain higher scores on the F, D, Pa, and Sc scales because these subjects came from "war-torn" countries. A multivariate analysis of variance yielded no significant differences between the three groups on any of the validity and clinical scales including F, D, Pa, and Sc. Recommendations for cross-national research are noted especially in light of the new version, or MMPI-2.

Adult↗
PubMed1994

DSM-III-R training in master's-level counseling programs.

The DSM-III--R is used by the subdisciplines of mental health including psychiatry, psychology, and social work. Yet, of all subdisciplines, it has historically met the most resistance from the counseling profession. Until the early 1980s, discussion of the DSM in the counseling literature was taboo. It has only been in the last 10 years that counselors have begun to discuss the role of the DSM in counseling. The purpose of this investigation was to examine the actual extent of DSM-III--R training in counseling programs. Analysis suggested that the counseling programs have included training in psychiatric diagnosis, but this training continues to meet resistance as it is inconsistent within the curricula of such programs.

Counseling↗
PubMed1993

Hispanic-white MMPI comparisons: does psychiatric diagnosis make a difference?

Recent research on Blacks or African-Americans in psychiatric settings suggests that Black-White MMPI differences are minimized or eliminated when researchers match or control for key moderator variables, including psychiatric diagnosis. This study attempted to determine whether Hispanic-White MMPI differences are either minimized or eliminated when Hispanics and Whites are matched on three key moderator variables--age, education, and psychiatric diagnosis. Results suggest that even after controlling for these variables, MMPI differences between Hispanics and Whites are evident. Recommendations for culturally sensitive Hispanic MMPI research are presented.

Adult↗
PubMed1992

MMPI-ER two-point codes of industrially injured Hispanic workers by DSM-III--R diagnosis.

The purpose of this study was to describe the MMPI-ER two-point codes of 492 Hispanic adults who had sustained work-related injuries and who had applied for workers' compensation benefits. More specifically, the focus was on whether there are unique MMPI two-point codes for Hispanic workers with three specific types of DSM-III--R diagnoses--adjustment disorder, anxiety disorder, and major depression. Analysis suggests that psychiatric condition or diagnosis may act as a moderator variable in Hispanic persons' MMPI performance, including MMPI two-point codes.

Accidents, Occupational↗
PubMed1991

MMPI differences among Mexican-American male and female psychiatric inpatients.

The purpose of this study was to examine to what extent Mexican-American male and female psychiatric patients, who share similar DSM-III--R diagnoses, differ on the MMPI. Differences were found on the Infrequency, Masculinity-Femininity, and Paranoia scales, with the 39 men obtaining significantly higher scores than the 21 women. These results, while suggesting possible differences in the phenomenology of depression, also suggest that MMPI differences between Mexican-American men and women may be reflective of culturally-defined sex roles. These results, when taken within the context of Mexican-American MMPI literature, indicate that researchers should always attempt to account for "gender" when conducting cross-ethnic MMPI comparisons. The practice of grouping the MMPIs of Mexican-American men and women for comparison with other ethnic groups should be discontinued in favor of comparisons that consider the effects of gender and ethnicity.

Adult↗
PubMed1990

MMPIs of Hispanic, black, and white DSM-III schizophrenics.

The purpose of this study was to compare the MMPI performance of Hispanic, black, and white mental patients who were matched on the psychiatric diagnosis of schizophrenia. It was hypothesized that ethnic patient groups from a maximum security hospital would not differ significantly on any of the 13 MMPI scales as a result of being equated on psychiatric diagnosis. A secondary purpose was to examine the most frequently occurring two-point high-point codes elicited by each of the ethnic groups. Significant multivariate differences were indicated among the MMPI scales and across ethnic groups. Significant univariate differences were found among the three ethnic groups on six of the 13 MMPI scales. The most frequently occurring two-point high-point code for Hispanic and white groups was the "8-2/2-8" code, while for the black group it was the "6-8/8-6" code. Results were discussed with regard to ethnicity, psychiatric diagnosis, and MMPI performance of ethnic/racial groups.

Black or African American↗
PubMed1990

MMPI comparisons of Hispanic- and white-American veterans seeking treatment for alcoholism.

Scores of 29 Hispanic- and 46 white-American alcoholics, who voluntarily sought psychiatric treatment for their alcoholism, were compared on the MMPI. It was hypothesized that Hispanic-American alcoholics would be better adjusted than white alcoholics on the validity and clinical scales of the MMPI. The hypothesis was supported, with Hispanic-Americans obtaining significantly lower scores than white veterans on the Pd, Mf, and Si scales. Hispanic and white patients did not differ on the remaining MMPI scales. The mean two-point code for Hispanic subjects was 2-8 (Depression-Schizophrenia) and for white patients 8-2 (Schizophrenia-Depression).

Adaptation, Psychological↗