Recommendations for toxicological investigations of drug-facilitated sexual assaults

The recent increase in reports of drug-facilitated sexual assaults has caused alarm in the general public and prompted forensic toxicologists from across North America to address the toxicological issues surrounding this matter. The authors have developed recommendations and guidelines to inform law enforcement, medical, and scientific personnel of the requirements for performing successful toxicological examinations in cases of drug-facilitated rape.     

Prenatal monitoring of ornithine transcarbamoylase deficiency in two families by DNA analysis

This study examined the variation in weight, height and body mass index of 1048 mothers living in a rural area of Bangladesh in relation to age, education, number of previous pregnancies, number of dead children, religion, family type, family size, and amount of land owned by the household. Multiple regression analysis revealed a positive relationship of education with all three variables. Moslem mothers were on average in better condition than Hindus. The number of dead children showed a negative relationship with height, weight and body mass index.     

The relation of birth order to sexual orientation in men and women

BACKGROUND: Neutral lipases are ubiquitous and diverse enzymes. The molecular architecture of the structurally characterized lipases is similar, often despite a lack of detectable homology at the sequence level. Some of the microbial lipases are evolutionarily related to physiologically important mammalian enzymes. For example, limited sequence similarities were recently noted for the Streptomyces exfoliatus lipase (SeL) and two mammalian platelet-activating factor acetylhydrolases (PAF-AHs). The determination of the crystal structure of SeL allowed us to explore the structure-function relationships in this novel family of homologous hydrolases. RESULTS: The crystal structure of SeL was determined by multiple isomorphous replacement and refined using data to 1.9 A resolution. The molecule exhibits the canonical tertiary fold of an alpha/beta hydrolase. The putative nucleophilic residue, Ser131, is located within a nucleophilic elbow and is hydrogen bonded to His209, which in turn interacts with Asp177. These three residues create a triad that closely resembles the catalytic triads found in the active sites of other neutral lipases. The mainchain amides of Met132 and Phe63 are perfectly positioned to create an oxyanion hole. Unexpectedly, there are no secondary structure elements that could render the active site inaccessible to solvent, like the lids that are commonly found in neutral lipases. CONCLUSIONS: The crystal structure of SeL reinforces the notion that it is a homologue of the mammalian PAF-AHs. We have used the catalytic triad in SeL to model the active site of the PAF-AHs. Our model is consistent with the site-directed mutagenesis studies of plasma PAF-AH, which implicate Ser273, His351 and Asp296 in the active site. Our study therefore provides direct support for the hypothesis that the plasma and isoform II PAF-AHs are triad-containing alpha/beta hydrolases.     

Dissecting the order of bacteriophage T4 DNA polymerase holoenzyme assembly

Most biological organisms rely upon a DNA polymerase holoenzyme for processive DNA replication. The bacteriophage T4 DNA polymerase holoenzyme is composed of the polymerase enzyme and a clamp protein (the 45 protein), which functions as a processivity factor by strengthening the interaction between DNA and the holoenzyme. The 45 protein must be loaded onto DNA by a clamp loader ATPase complex (the 44/62 complex). In this paper, the order of events leading to holoenzyme formation is investigated using a combination of rapid-quench and stopped-flow fluorescence spectroscopy kinetic methods. A rapid-quench strand displacement assay in which the order of holoenzyme component addition is varied provided data indicating that the rate-limiting step in holoenzyme assembly is associated with the clamp loading process. Pre-steady-state analysis of the clamp loader ATPase activity demonstrated that the four bound ATP molecules are hydrolyzed stepwise during the clamp loading process in groups of two. Clamp loading was examined with stopped-flow fluorescence spectroscopy from the perspective of the clamp itself, using a site-specific, fluorescently labeled 45 protein. A mechanism for T4 DNA polymerase holoenzyme assembly is proposed in which the 45 protein interacts with the 44/62 complex leading to the hydrolysis of 2 equiv of ATP, and upon contacting DNA, the remaining two ATP molecules bound to the 44/62 complex are hydrolyzed. Once all four ATP molecules are hydrolyzed, the 45 protein is poised on DNA for association with the polymerase to form the holoenzyme.     

DNA sequence analysis by MALDI mass spectrometry

Conventional DNA sequencing is based on gel electrophoretic separation of the sequencing products. Gel casting and electrophoresis are the time limiting steps, and the gel separation is occasionally imperfect due to aberrant mobility of certain fragments, leading to erroneous sequence determination. Furthermore, illegitimately terminated products frequently cannot be distinguished from correctly terminated ones, a phenomenon that also obscures data interpretation. In the present work the use of MALDI mass spectrometry for sequencing of DNA amplified from clinical samples is implemented. The unambiguous and fast identification of deletions and substitutions in DNA amplified from heterozygous carriers realistically suggest MALDI mass spectrometry as a future alternative to conventional sequencing procedures for high throughput screening for mutations. Unique features of the method are demonstrated by sequencing a DNA fragment that could not be sequenced conventionally because of gel electrophoretic band compression and the presence of multiple non-specific termination products. Taking advantage of the accurate mass information provided by MALDI mass spectrometry, the sequence was deduced, and the nature of the non-specific termination could be determined. The method described here increases the fidelity in DNA sequencing, is fast, compatible with standard DNA sequencing procedures, and amenable to automation.     

Interaction of birth order, handedness, and sexual orientation in the Kinsey interview data.

Recent evidence indicates that 2 of the most consistently observed correlates of men's sexual orientation--handedness and older brothers--may be linked interactively in their prediction of men's sexual orientation. In this article, the authors studied the relationship among handedness, older brothers, and men's sexual orientation in the large and historically significant database originally compiled by Alfred C. Kinsey and his colleagues (A. C. Kinsey, W. B. Pomeroy, & C. E. Martin, 1948). The results demonstrated that handedness moderates the relationship between older brothers and sexual orientation. Specifically, older brothers increased the odds of homosexuality in right-handers only; in non-righthanders, older brothers did not affect the odds of homosexuality. These results refine the possible biological explanations reported to underlie both the handedness and older brother relationships to men's sexual orientation. These results also suggest that biological explanations of men's sexual orientation are likely relevant across time, as the Kinsey data comprise an older cohort relative to modern samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Binding of two novel bisdaunorubicins to DNA studied by NMR spectroscopy

In the search for new generations of anthracycline drugs, lower cytotoxic side effects and higher activity against resistant cancer cells are two major goals. A new class of bis-intercalating anthracycline drugs has been designed, synthesized, and shown to have promising activity against multidrug-resistant cells. Two daunorubicins symmetrically linked together via a p-xylenyl group, either at their N3' (compound WP631) or N4' sites (compound WP652), exhibit extraordinary DNA binding affinities. We have used high-resolution NRM studies to understand the DNA binding mode of these two new bis-daunorubicin anticancer compounds. The structures of the WP631-d(ACGTACGT)2 and the WP652-d(TGTACA)2 complexes have been determined by NOE-restrained refinement. WP631 binds strongly to the 5'-CG(A/T)(A/T)CG hexanucleotide sequence, with the aglycons intercalated between the two CpG sites at both ends of the hexanucleotide sequence. The overall conformation of the WP631-d(CGTACG)2 part is remarkably similar to the crystal structure of the 2:1 complex of daunorubicin and d(CGTACG)2, as predicted previously [Gao, Y.-G., & Wang, A.H.H. (1996), J. Biomol. Struct. Dyn. 13, 103-117]. In contrast, the related bis-intercalator WP652 prefers the 5'-PyGTPu tetranucleotide sequence, with the aglycons intercalated between the PypG and TpPu sites. The binding of WP652 to DNA results in a severely distroted B-DNA duplex with the p-xylenyl tether moiety significantly protruded away from the bottom of the minor groove. While WP652 in some ways behaves similarly to other anticancer bis-intercalating antibiotics (e.g., triostine A and echinomycin), the detailed interactions between those two classes of bis-intercalators are quite different.     

The interaction of fraternal birth order and body size in male sexual orientation.

A late fraternal birth order has been demonstrated numerous times in homosexual men. Body size has been less studied with regard to the development of sexual orientation and has demonstrated contradictory results. In this research, the relations among fraternal birth order, body size, and sexual orientation were examined in a Canadian sample of homosexual and heterosexual men. An interaction between fraternal birth order and height was observed, with a homosexual orientation most likely to occur in men with a high number of older brothers and shorter stature. No significant interactive effects were observed for weight. The results suggest that the mechanism underlying the fraternal birth order phenomenon has an effect on physical development that lasts and is detectable into adulthood (i.e., adult stature). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual DNA bands obtained by RAPD analysis of canine genomic DNA often contain multiple DNA sequences

We present a case of Langerhans' cell histiocytosis (LCH) of the liver and spleen in an adult. The imaging features are different from those in the few previously reported cases of individual organ involvement by LCH.     

Diagnosis of sickle-cell disease by DNA analysis in Nigeria

OBJECTIVE: To compare genotyping of leucocyte DNA by PCR and Dde I with the conventional genotyping of haemoglobin of the same subject. DESIGN: Comparative study. SUBJECTS: 25 adults, 16 males and nine females. MAIN OUTCOME MEASURES: Predictability. RESULTS: In all cases the results were comparable. CONCLUSIONS: The technology can be applied locally to prenatal diagnosis of sickle-cell disease by chorionic sampling and, therefore, improve the management of sickle-cell disease in Nigeria.     

Alpha-thalassemia carrier identification by DNA analysis in the screening for thalassemia

Recent advances in technology have not substantially changed the high mortality rate associated with acute renal failure (ARF). To obtain a simple, valid prognostic index, we retrospectively evaluated the relative importance of demographic data, causes (acute insults) of renal failure, and comorbid clinical conditions for the outcome in 102 ARF patients who received renal replacement therapy with an overall mortality rate of 65% (66 of 102). There were no significant differences between survivors and nonsurvivors in age and gender. Mortality according to acute insults was similar to that of the whole population studied. Of the 10 clinical conditions at the time of the first renal replacement therapy, mechanical ventilation (p = 0.0002), cardiac failure (p = 0.0006), hepatic failure (p = 0.003), central nervous system dysfunction (p = 0.005), and oliguria (p = 0.04) were found to be significantly related to mortality by univariate analysis. Furthermore, multivariate analysis demonstrated that only mechanical ventilation, cardiac failure, and hepatic failure were significant risk factors. Survival was directly related to the number of significant variables in univariate analysis: zero, 89% (8 of 9); one, 62% (21 of 34); two, 19% (5 of 27); three, 10% (2 of 20); four, 0% (0 of 8); five, 0% (0 of 4). This simple and early prognostic index, derived from the assessment of clinical conditions which were easily determined at the patient's bedside, could be useful for outcome prediction in ARF patients requiring renal replacement therapy.     

Metric and comparative analysis of sexual dimorphism in the Thai femur

Identification of sex from the skeleton is an important demographic assessment in medicolegal investigations. Studies have demonstrated that populations differ from each other in size and proportions and that these differences can affect the metric assessment of sex. It is therefore vital to determine if population differences are great enough to necessitate group-specific standards. To date, there have been no attempts to create standards of assessment for modern Thais. Therefore the purpose of this research is to establish standards from which to determine sex from the femur using a new skeletal collection housed at the Chiang Mai University Department of Anatomy. The sample is composed of 104 individuals (70 males, 34 females). Six standard osteometric dimensions including maximum length, maximum head diameter, midshaft circumference, midshaft anterior-posterior and transverse diameters, and bicondylar breadth were measured and analyzed by stepwise discriminant function statistics. To understand population differences, formulas derived from Chinese, South African whites and American whites and blacks using the same method and variables were tested on the Thai sample. Results indicated that maximum head diameter and bicondylar breadth are the optimal combination for sex diagnosis and yielded 94.2% accuracy. Direct analysis using predetermined single or multiple variables also revealed bicondylar breadth as the best single dimension (93.3%). In cross-tests on the Thais, the Chinese formula gave the most favorable outcome with unsatisfactory results for all other groups. The present research confirms that sexual dimorphism is better reflected in breadth dimensions than in bone length. Comparisons showed that Thais are very different metrically from whites and blacks, and although they most resemble the Chinese, these two groups are not identical. These findings underscore the need for population-specific formulas for identification of sex from the skeleton.     

DNA analysis in hepatoblastoma by flow and image cytometry

BACKGROUND: In several types of tumors, including hepatocellular carcinoma, prognosis could be correlated with DNA ploidy. Few studies have been performed on hepatoblastoma with contradictory results. METHODS: Twenty-nine cases of nonpretreated hepatoblastoma were studied with flow cytometry and image cytometry for DNA index and proliferation index using paraffin-embedded tissue. RESULTS: Twenty-three (79.9%) tumors were diploid, and 6 (20.7%) were aneuploid (hyperdiploid). Patients with diploid tumors were younger than those with aneuploid tumors. With regard to stage, diploid tumors were almost equally distributed among stages (tumor, lymph node metastases, distant metastases), whereas aneuploid tumors tended to occur in higher stages (tumor, lymph node metastases, distant metastases). Diploid tumors had clearly a better prognosis than aneuploid tumors, although the difference was not statistically significant (flow cytometry, P = 0.06; image cytometry, P = 0.16). A more favorable prognosis was also noted for hepatoblastomas with low-proliferation index (< or = 7%), but the difference from tumors with high-proliferation index (> 7%) again was not statistically significant (P = 0.16). CONCLUSIONS: Although no statistically significant differences in prognosis between hepatoblastomas with diploid and aneuploid DNA content, respectively, were found, there is a clear tendency that diploid hepatoblastomas behave more favorably. The same is true for hepatoblastomas with low-proliferation index.     

Hierarchical order in a satellite DNA from the European brown frog Rana dalmatina

We have cloned and sequenced a 341 bp EcoRV fragment of a repetitive DNA from the European brown frog Rana dalmatina. This fragment contained 11 copies in tandem of the 31 bp long repeat of a satellite DNA, that was named RdS2. RdS2 is species-specific, is not A+T rich and represents about 0.24% of the frog genome (3.5 x 10(5) copies of repeats per haploid genome). Southern blots of Rana dalmatina. DNA partially digested with EcoRV and RsaI indicated that RdS2 also contains high-order repeats with periodicities varying from 10 to 26 copies of the 31 bp unit repeat. Thus, RdS2 appears to have a hierarchical order like a number of satellite DNAs from other vertebrate and invertebrate genomes.