Differentiating poor validity from probable impairment on the medical symptom validity test: a cross-validation study

Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.     

Disproportionate outdating of group A blood

The authors studied the factors responsible for the disproportionate outdating of group A blood compared with group O blood over a 6-month interval. Distribution, transfusion, and outdate data for 99,251 units of blood were collected from representative hospitals within the region served by the Atlanta Regional Red Cross Blood Center. Factors evaluated included: neonatal transfusion of type O blood to type A recipients; use of type O blood in emergencies or due to group-specific shortages; demographic donor and recipient differences; and blood importing practices. Of 43,757 group O units (44.1% of total) available for distribution, 2050 (4.7%) were outdated, compared with 3908 (10.7%) of 36,501 group A units (36.8% of total). One thousand two hundred and seventy-nine units of type O blood were transfused to recipients who were not type O, including 842 group A neonatal patients. A larger inner-city hospital, where 46.8 percent of recipients were group O and 29.2 percent were group A, accounted for 180 more group O and 509 fewer group A transfusions than would be expected if donor-recipient ABO distributions were the same. Three hundred and seventy-four more group A units were imported than were needed. ABO-mismatched transfusions due to shortage or emergency were insignificant. It was concluded that increased use of group O blood for neonatal transfusions, donor-recipient differences in blood group frequencies, and blood importing practices are the major factors that increase the rate of group A outdating.     

Hematologic problems in psychosomatic medicine.

Vitamin B12 deficiency is associated with problems in cognition, mood, psychosis, and less commonly, anxiety. Folate deficiency primarily is associated with problems in mood. Patients who have sickle cell disease, a disease of chronic pain, experience difficulties with depression, anxiety, stigma, and are at risk for substance abuse and dependence. Patients with hemophilia have benefited from advances in treatment; however, their morbidity and mortality were compounded in those who received blood products contaminated with HIV, or hepatitis B and C. Psychiatrists who practice psychosomatic medicine should expect to encounter patients with the above problems, as they are frequently seen in medical settings. Finally, most of the commonly used psychotropic medications have uncommon but potentially important hematologic side effects or may interact with the anticoagulants used in medically ill patients.     

WAIS-R verbal-performance IQ discrepancies in persons with lateralized lesions: utility of a seven subtest short form.

WAIS-R Verbal-Performance IQ difference scores for Ward's (1990) seven subtest short form and the complete WAIS-R were examined in patients with lateralized and diffuse lesions. For both versions, the expected Performance > Verbal pattern was observed in the right hemisphere lesion group, while no summary score differences were seen in the left hemisphere group. Verbal-Performance IQ discrepancies for the short form fell within +/- 5 points of the WAIS-R discrepancy scores in about 75%of the cases, regardless of lesion location. Statistically reliable IQ differences between the complete and abbreviated WAIS-R attained 66%, 91%, and 89% agreement for the left, right, and diffuse groups, respectively. The results support the clinical utility of the seven subtest short form.     

CTLA-4 is required for the induction of high dose oral tolerance

Mucosal and systemic administrations of high dose antigens induce long- lasting peripheral T cell tolerance. We and others have shown that high dose peripheral T cell tolerance is mediated by anergy or deletion and is preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2 (CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell activation and immune regulation. In the present study, we examined the roles of the B7 co-stimulation pathway in the generation of high dose peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4 interaction at the time of tolerance induction partially prevented T cell tolerance, whereas selective blockade of B7:CTLA-4 interaction completely abrogated peripheral T cell tolerance induced by either oral or i.p. antigens. These results suggest that CTLA-4-mediated feedback regulation plays a crucial role in the induction of high dose peripheral T cell tolerance.      

Molecular genetic characterization of XRCC4 function

XRCC4 is a generally expressed protein of 334 amino acids that is involved in the repair of DNA double-strand breaks and in V(D)J recombination, but its function is unknown. In this study, we have used a mutational approach and the yeast two-hybrid method to perform an initial characterization of this protein. We show that the XRCC4 protein is located in the nucleus. We also demonstrate that several potential phosphorylation sites are not required for XRCC4 function in a transient V(D)J recombination assay. In addition, we show that XRCC4 forms a homodimer in vivo with the homodimerization domain being located within amino acids 115-204. Finally, we define a core domain of XRCC4 that functions in V(D)J recombination and comprises amino acids 18-204. Potential functions of XRCC4 are discussed.