Decreased axial diffusivity within language connections: a possible biomarker of schizophrenia risk

Siblings of patients diagnosed with schizophrenia are at elevated risk for developing this disorder. The nature of such risk associated with brain abnormalities, and whether such abnormalities are similar to those observed in schizophrenia, remain unclear. Deficits in language processing are frequently reported in increased risk populations. Interestingly, white matter pathology involving fronto-temporal language pathways, including arcuate fasciculus (AF), uncinate fasciculus (UF), and inferior occipitofrontal fasciculus (IOFF), are frequently reported in schizophrenia. In this study, high spatial and directional resolution diffusion MRI data was obtained on a 3T magnet from 33 subjects with increased familial risk for developing schizophrenia, and 28 control subjects. Diffusion tractography was performed to measure white matter integrity within AF, UF, and IOFF. To understand these abnormalities, Fractional Anisotropy (FA, a measure of tract integrity) and Trace (a measure of overall diffusion), were combined with more specific measures of axial diffusivity (AX, a putative measure of axonal integrity) and radial diffusivity (RD, a putative measure of myelin integrity). Results revealed a significant decrease in Trace within IOFF, and a significant decrease in AX in all tracts. FA and RD anomalies, frequently reported in schizophrenia, were not observed. Moreover, AX group effect was modulated by age, with increased risk subjects demonstrating a deviation from normal maturation trajectory. Findings suggest that familial risk for schizophrenia may be associated with abnormalities in axonal rather than myelin integrity, and possibly associated with disruptions in normal brain maturation. AX should be considered a possible biomarker of risk for developing schizophrenia.

Reduced fractional anisotropy and axial diffusivity in white matter in 22q11.2 deletion syndrome: a pilot study

Individuals with 22q11.2 deletion syndrome (22q11.2DS) evince a 30% incidence of schizophrenia. We compared the white matter (WM) of 22q11.2DS patients without schizophrenia to a group of matched healthy controls using Tract-Based-Spatial-Statistics (TBSS). We found localized reduction of Fractional Anisotropy (FA) and Axial Diffusivity (AD; measure of axonal integrity) in WM underlying the left parietal lobe. No changes in Radial Diffusivity (RD; measure of myelin integrity) were observed. Of note, studies in chronic schizophrenia patients report reduced FA, no changes in AD, and increases in RD in WM. Our findings suggest different WM microstructural pathology in 22q11.2DS than in patients with schizophrenia.

Predoctoral directors: who are they and what do they do in these trying times?

BACKGROUND AND OBJECTIVES

Family medicine faces declining student interest and funding. Predoctoral directors will help lead efforts to overcome these challenges. Academic success will be important for predoctoral directors to be effective leaders in academic health centers. We therefore sought to describe predoctoral directors and factors associated with their academic success.

METHODS

We carried out a cross-sectional survey of all family medicine predoctoral directors at US allopathic medical schools using a Web-based questionnaire. The response rate was 82%. We measured academic success using a variable combining rank and tenure status. We used bivariate analysis and multiple linear regression analysis to identify factors associated with academic success.

RESULTS

The mean age of predoctoral directors is 47, and 45% are women. Forty-two percent are assistant professors, 36% associate professors, 20% full professors, and 33% are on a tenure track. Sixty-four percent of predoctoral programs receive Title VII funding, and 63% of predoctoral directors believe that loss of Title VII funding will adversely affect student education. Factors associated with academic success include years since residency, total publications, years as predoctoral director, male gender, state funding for predoctoral family medicine programs, and participation in an academic fellowship. Involvement in educational research was associated with number of publications.

CONCLUSIONS

Providing predoctoral directors with the skills and support needed to study their educational undertakings and publish their findings may help them achieve academic success. Medical educators must assess the effects of loss of Title VII funding on predoctoral education while seeking new sources of funding.

Cancer mortality in the 30s foretells cancer of the 80s in Louisiana

Examination of secular trends suggests that the high cancer mortality rates of the 1980s could have been foretold by the excessive rates in the 1930s in Louisiana. Those same sites which were excessive in the 1930s, reflecting exposure to risk factors in the early 1900s, still predominate in the 1980s. Because of the poor survival associated with lung cancer and the increase in smoking, the increase in lung cancer had the greatest impact on the mortality trend in the all sites combined category. The stability of the cancer problem and the lack of progress in reducing cancer over the last 50 years is seen as a harbinger of the cancer problem over the next 50 years.