Measurement of chemical analytes in vitreous humor: stability and precision studies

The analytic accuracy and precision for measurement of chemical analytes in vitreous humor (VH) are critical if results are to be used in forensic pathology. The purpose of our study was to demonstrate the stability and the reproducibility of VH sodium, potassium, chloride, glucose, urea nitrogen, acetone, and beta-hydroxybutyrate in specimens obtained from both eyes in medical examiner cases. We also compared with calculated VH osmolalities. Small but significant increases were observed in VH electrolyte concentrations in specimens refrigerated 6-12 months: sodium pre 144 mmol/L, post 151 mmol/L; potassium pre 12.0 mmol/L, post 12.8 mmol/L; chloride pre 121 mmol/L, post 123 mmol/L. No differences were observed between eyes, and within-day precision for all electrolyte measurements were excellent, (<1%). Frozen specimens showed significantly higher measured (439 mOsmol/kg) as compared with calculated osmolality (305 mOsmol/kg), with 1% within-day precision and no significance between eye variation for glucose and urea nitrogen. In 20 of 24 medical cases selected for possible ketoacidosis, measurement of beta-hydroxybutyrate concentrations appears to be a promising diagnostic biomarker for confirming suspected ketosis in medical examiner cases by means of VH analysis.     

Changes in Intimate Partner Violence During Pregnancy

Women's experiences of partner violence, both before and during pregnancy, are described using a convenience sample of women recruited from prenatal clinics. Included were an index group of women who told their clinicians that they had been physically abused during pregnancy, and a comparison group of women who told their clinicians that they had not been physically abused during pregnancy (even though later more detailed assessment found that some of these comparison women had experienced such violence). The women averaged 27 years of age, with 83% being high school graduates, 26% being married, and 66% having had previous children. The Conflict Tactics Scales 2 assessed rates of partner violence victimization of the women and their male partners, including psychological aggression, physical assault, and sexual coercion. Injuries also were assessed. Results showed that comparison men were physically assaulted at significantly higher rates than were their female partners, both before and during pregnancy (even though these victimization rates were much lower than those seen among the index couples). Index women experienced higher rates of psychological aggression, physical assault, and sexual coercion than did their male partners, and these women were significantly more likely than their male partners to be injured. Pregnancy onset was associated with significant increases in the rates of psychological aggression among both the index and comparison couples. In addition, the index women experienced a significantly increased rate of sexual violence victimization during pregnancy. However, pregnancy was not associated with significant increases in the rates of physical assault or violence-related injuries among the index or comparison couples.     

Laser microdissection separation of pure spermatozoa from epithelial cells for short tandem repeat analysis

Short tandem repeat (STR) analysis is a valuable tool in identifying the source of biological stains, particularly from the investigation of sexual assault crimes. Difficulties in analysis arise primarily in the interpretation of mixed genotypes when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. The feasibility of applying laser microdissection (LMD) technology to precisely separate sexual assault cell mixtures by visual inspection coupled with laser dissection was assessed through three experiments. First, various histological stains were evaluated for use with LMD and DNA analysis. Second, different DNA isolation methods were evaluated on LMD-collected cells. Finally, STR analysis was performed on LMD-separated sperm cells from mixtures of semen and female buccal epithelial cells. The results indicated (a) hematoxylin/eosin staining performed best in its ability to differentiate sperm and epithelial cells while exhibiting the least negative effect on further downstream analysis; (b) both QIAamp and Lyse-N-Go methods were useful for recovery of DNA from LMD-collected sperm cells; and (c) LMD separation provided clear STR profiles of the male donor with the absence of any additional alleles from the female donor. This report describes an efficient, low-manipulation LMD method for the efficient separation of spermatozoa from two-donor sperm/epithelial cell mixtures.     

Violence in relationships: A seventh grade inventory of knowledge and attitudes

The purpose of this research was to contribute to existing efforts of battered women's advocates, schools, and researchers by developing a valid and reliable inventory to evaluate educational interventions regarding violence in relationships. Content validity was established by national experts (N=32)solicited to complete an inventory rating scale and comment on the statements' ability to elicit early adolescents' knowledge and attitudes about violence in relation-ships. The revised inventory was tested with seventh grade health education students (N=99).The test-retest reliability criterion was .50. Spearman's rho correlations were .566 for the knowledge section and .669 for the attitude section. Knowledge and attitude sections were measured for internal con- sistency with Cronbach's alpha, with respective values of .3178 and .7207. Item analyses with Wilcoxon Rank Sum tests identified 11 knowledge statements and one attitude statement as significantly discriminating at both test and retest. Gender differences were noted and additional findings were reported. Recommendations for the further establishment of a valid and reliable inventory were made.