Fábio Delwing

Analysis of the fluorescence of body fluids on different surfaces and times.

The use of screening techniques, such as an alternative light source (ALS), is important for finding biological evidence at a crime scene. The objective of this study was to evaluate whether biological fluid (blood, semen, saliva, and urine) deposited on different surfaces changes as a function of the age of the sample. Stains were illuminated with a Megamaxx™ ALS System and photographed with a Canon EOS Utility™ camera. Adobe Photoshop™ was utilized to prepare photographs for analysis, and then ImageJ™ was used to record the brightness values of pixels in the images. Data were submitted to analysis of variance using a generalized linear mixed model with two fixed effects (surface and fluid). Time was treated as a random effect (through repeated measures) with a first-order autoregressive covariance structure. Means of significant effects were compared by the Tukey test. The fluorescence of the analyzed biological material varied depending on the age of the sample. Fluorescence was lower when the samples were moist. Fluorescence remained constant when the sample was dry, up to the maximum period analyzed (60 days), independent of the substrate on which the fluid was deposited, showing the novelty of this study. Therefore, the forensic expert can detect biological fluids at the crime scene using an ALS even several days after a crime has occurred.

Protective effect of antioxidants on blood oxidative stress caused by arginine.

In this study, we investigated in vivo and in vitro effect of arginine on parameters of oxidative stress namely thiobarbituric acid‐reactive substances (TBA‐RS) and total radical‐trapping antioxidant parameter (TRAP) in plasma and on the antioxidant enzymes activities catalase (CAT), glutathione peroxidase (GSH‐Px), and superoxide dismutase (SOD) in erythrocytes of rats. Results showed that acute administration reduced TRAP and CAT activity and increased TBA‐RS. Furthermore, in vitro studies did not alter oxidative parameters studied. The influence of Nω‐nitro‐l‐arginine methyl ester (l‐NAME) and antioxidants (α‐tocopherol plus ascorbic acid) on the effects elicited by arginine was also studied. In addition, simultaneous injection of l‐NAME or treatment with antioxidants prevented the alteration on TRAP, TBA‐RS, and CAT activity caused by arginine. Data indicate that oxidative stress induction is probably mediated by the generation of NO and/or ONOO− and other free radicals, because l‐NAME and these antioxidants prevented these effects caused by arginine.

Dental anthropology of a Brazilian sample: Frequency of nonmetric traits

Dental elements are valuable tools in a study of ancient populations and species, and key-features for human identification; among the dental anthropology field, nonmetric traits, standardized by ASUDAS, are closely related to ancestry. This study aimed to analyze the frequency of six nonmetric traits in a sample from Southeast Brazil, composed by 130 dental casts from individuals aged between 18 and 30, without foreign parents or grandparents. A single examiner observed the presence or absence of shoveling, Carabellis cusp, fifth cusp, 3-cusped UM2, sixth cusp, and 4-cusped LM2. The frequencies obtained were different from the ones shown by other researches to Amerindian and South American samples, and related to European and sub-Saharan frequencies, showing the influence of this groups in the current Brazilian population. Sexual dimorphism was found in the frequencies of Carabellis cusp, 3-cusped UM2, and sixth cusp.

Effectiveness of dental records in human identification

Forensic dentistry, a branch of the forensic sciences, plays an important role within postmortem human identification, especially in cases of corpses that are charred, skeletonized or in an advanced state of decomposition. Identification of human remains via dental knowledge is done using a comparative technique, which is simple, inexpensive and reliable, the aim of which is to compare dental records and information recorded by dentists in clinical appointments made before an individuals death, with postmortem dental records obtained via forensic examination. In this context, the present study aims to demonstrate the importance of dental records and the effectiveness of forensic dentistry in human identification, illustrated by the report of a case that was conducted at the Sao Luis Coroners Office in the Brazilian state of Maranhao. It may be concluded that dental records maintained by a dentist, when complete, properly structured and correctly archived, retain important personal information and are fundamental tools in the process of human identification.