Cytogenetic analysis was carried out in unrelated schizophrenic patients, unrelated controls and patients and family members in multiplex families. The size distribution of chromosome 1 heterochromatic region (1qH, C-band variants) among 21 unrelated schizophrenic patients was different from that found in a group of 46 controls. The patient group had 1qH variants of smaller size than the control group (P < 0.01). Incubation of phytohemagglutinin-treated blood lymphocytes with 5-azacytidine (which causes decondensation and extension of the heterochromatin) led to a lesser degree of heterochromatin decondensation in a group of patients than in the controls (7 schizophrenic, 9 controls, P < 0.01). The distribution of phenotypes of Duffy blood group system [whose locus is linked to the 1qH region (Donahue et al.: Proc Natl Acad Sci USA 61:949-955, 1968; Rouleau et al.: Genomics 7:313-318, 1990)] among 28 schizophrenic patients was also different from that in the general population. Cosegregation of schizophrenia with a 1qH (C-band) variant and Duffy blood group allele was observed in one of six multiplex families. The overall results suggest that alterations within the Duffy/1qH region are involved in schizophrenia in some cases. This region contains the locus of D5 dopamine receptor pseudogene 2 (1q21.1), which is transcribed in normal lymphocytes (Takahashi et al.: FEBS Lett 314:23-25, 1992).

A Short Mental Test (SMT) composed of 26 items was evaluated for screening dementia, taking into account the effect of age and education. The relative contribution of individual items was assessed. The SMT was administered to healthy and demented subjects. Validity was established by a significant relationship between the total score on the SMT (as well as individual items) and the diagnosis established according to DSM-III R criteria. The best diagnostic accuracy (88.4%) was achieved using a cut-off score of 79 correct responses. The question that most successfully diagnosed dementia was subtraction of serial sevens. Subsequent ranking revealed the importance of items requiring abstraction and time orientation. Immediate recall and personal information were least helpful. Age negatively correlated with total scores, but affected recent memory, sentence repetition and proverb interpretation in the higher-schooled population only. Poor schooling evenly lessened general performance.

PLT counts are higher in suicidal hospitalized adolescents than in nonsuicidal inpatients, as well as than in controls.

These results suggest an ethnic difference in the age trends of postpartum Hb levels. Clinically, significant changes may occur between the ages of 27 and 30 years.