Cranial suture closure as an age indicator: A review.

Cranial suture closure has been recognized for over a century as a useful trait for age estimation. Although this indicator has become a standard feature of age assessment protocols in skeletal remains, serious questions have been raised about its reliability. This article attempts to provide a comprehensive review of cranial suture closure as an age indicator from several perspectives, including its anatomy and history, as well as issues relating to validation, statistics, and the potential of technological advancements to improve outcomes. We further suggest a path forward for the use of cranial suture closure as an estimator of age. Although its unreliability has been widely reported, cranial suture closure still appears to have value as an aging method, and it is hoped that the information contained in this article can serve as a stepping stone toward more effective use of this indicator. The cranium is often more durable than other skeletal elements in both archaeological and forensic circumstances, so maximizing the effectiveness of cranial indicators is an important goal. It is hoped that recent advancements in technology and in analytical approaches to the cranial sutures could breathe some new life into this feature as an indicator of age.

Factors associated with rerupture of intracranial aneurysms after endovascular treatment: A retrospective review of 11years experience at a single institution and review of the literature.

Aneurysm rebleeding following initial endovascular management is uncommon, and the factors associated with its occurrence are poorly defined. We retrospectively analyzed a consecutive series of patients presenting with aneurysmal subarachnoid hemorrhage who underwent endovascular management to determine factors associated with rebleeding. Rebleeding occurred in 7/183 (3.8%) patients, 6 of which had an adjacent hematoma on initial neuroimaging. Aneurysms were located on the ACoA (n=5), PCoA (n=1), and MCA (n=1). Sizes ranged from 3.5 to 13.0mm (mean 8.0), with neck sizes ranging from 1.8 to 4.6mm (mean 3.2). Time-to-rerupture ranged from hours to years, with 3/7 cases rebleeding within 30days and 4/7 cases rebleeding later than 30days. Initial incomplete angiographic occlusion occurred in 2/3 cases of early rebleeding. The presence of adjacent intracerebral hematoma (ɸ=0.354, p<0.005), increasing Fisher Grade (t(9.4)=7.72, p<0.005), and aneurysmal outpouching (ɸ=0.265, p<0.005) were found to be the only factors associated with rerupture status. Recurrent hemorrhage following endovascular management of ruptured intracranial aneurysms is an uncommon but important source of morbidity, particularly in the early post-embolization period. The presence of high-risk features, such as an adjacent intracerebral hematoma or aneurysm outpouching, warrant early and frequent angiographic follow up to document stability and mitigate rupture risk.

Osteometric sex estimation from the os coxa in a Thai population.

The coxal bone shows a very high degree of sexual dimorphism both morphologically and metrically. However, despite a number of recent studies on sex estimation from the skeleton in Thailand, no osteometric methods of sexing the Thai os coxa have been proposed. Therefore, the aim of this study was to develop a standard sex estimation method for a Thai population by examining the efficacy of six coxal bone measurements and eight indices obtained from 200 Thai skeletons. Independent samples t-tests revealed statistically significant differences between males and females for all but one of the measurements. The equation with the highest correct allocation accuracy was based on four measurements (pubis length, ischium length, total height and acetabulum diameter) and had a predicted and cross-validated accuracy of 96.9% and a tested accuracy of 97.5% on a holdout sample of 40 individuals. The single variable equation with the highest correct allocation accuracy of 94.4% and a tested accuracy of 97.5% was for the ischiopubic index, which is calculated from ischium length and pubis length. Percentage accuracies in predicting sex from these equations were higher than many previous studies, suggesting high levels of sexual dimorphism in the Thai os coxa.

Small molecule hydration energy and entropy from 3D-RISM.

Implicit solvent models offer an attractive way to estimate the effects of a solvent environment on the properties of small or large solutes without the complications of explicit simulations. One common test of accuracy is to compute the free energy of transfer from gas to liquid for a variety of small molecules, since many of these values have been measured. Studies of the temperature dependence of these values (i.e. solvation enthalpies and entropies) can provide additional insights into the performance of implicit solvent models. Here, we show how to compute temperature derivatives of hydration free energies for the 3D-RISM integral equation approach. We have computed hydration free energies of 1123 small drug-like molecules (both neutral and charged). Temperature derivatives were also used to calculate hydration energies and entropies of 74 of these molecules (both neutral and charged) for which experimental data is available. While direct results have rather poor agreement with experiment, we have found that several previously proposed linear hydration free energy correction schemes give good agreement with experiment. These corrections also provide good agreement for hydration energies and entropies though simple extensions are required in some cases.

The evolutionary origin and population history of the grauer gorilla.

Gorillas living in western central Africa (Gorilla gorilla) are morphologically and genetically distinguishable from those living in eastern central Africa (Gorilla beringei). Genomic analyses show eastern gorillas experienced a significant reduction in population size during the Pleistocene subsequent to geographical isolation from their western counterparts. However, how these results relate more specifically to the recent biogeographical and evolutionary history of eastern gorillas remains poorly understood. Here we show that two rare morphological traits are present in the hands and feet of both eastern gorilla subspecies at strikingly high frequencies (>60% in G. b. graueri; ∼28% in G. b. beringei) in comparison with western gorillas (<1%). The intrageneric distribution of these rare traits suggests that they became common among eastern gorillas after diverging from their western relatives during the early to middle Pleistocene. The extremely high frequencies observed among grauer gorillas-which currently occupy a geographic range more than ten times the size of that of mountain gorillas-imply that grauers originated relatively recently from a small founding population of eastern gorillas. Current paleoenvironmental, geological, and biogeographical evidence supports the hypothesis that a small group of eastern gorillas likely dispersed westward from the Virungas into present-day grauer range in the highlands just north of Lake Kivu, either immediately before or directly after the Younger Dryas interval. We propose that as the lowland forests of central Africa expanded rapidly during the early Holocene, they became connected with the expanding highland forests along the Albertine Rift and enabled the descendants of this small group to widely disperse. The descendant populations significantly expanded their geographic range and population numbers relative to the gorillas of the Virunga Mountains and the Bwindi-Impenetrable Forest, ultimately resulting in the grauer gorilla subspecies recognized today. This founder-effect hypothesis offers some optimism for modern conservation efforts to save critically endangered eastern gorillas from extinction.

Making the most of the imaging we have: using head MRI to estimate body composition.

AIM: To investigate the use of clinical head magnetic resonance imaging (MRI) in determining body composition and to evaluate how well it correlates with established measures based on abdominal computed tomography (CT). MATERIALS AND METHODS: Ninety-nine consecutive patients were identified who had undergone both brain MRI and abdominal CT within a 2-week span. Volumes of fat and muscle in the extracranial head were measured utilising several techniques by both abdominal CT and head MRI. RESULTS: MRI-based total fat volumes in the head correlated with CT-based measurements of fat in the abdomen using both single-section (r=0.64, p<0.01) and multisection (r=0.60, p<0.01) techniques. No significant correlation was found between muscle volumes in the abdomen and head. CONCLUSION: Based on the present results, head MRI-based measures may provide a useful surrogate for CT measurements of abdominal fat, particularly in patients with neurological cancers, as head MRI (and not abdominal CT) is routinely and repeatedly obtained for the purpose of clinical care for these patients.

Measurement standards for human metacarpals.

Standards for measuring the metacarpals are absent from commonly used osteometric guides. Perhaps the closest to a set of standard measurements in common use today are those proposed by Scheuer and Elkington (Scheuer and Elkington: J Forensic Sci 38 (1993) 769-788) for forensic sex assessment. They include caliper measurements of interarticular length, base and head width, base and head height, and maximum midshaft diameter. Over the last decade, a new set of measurements that encompass similar dimensions to those used by Scheuer and Elkington, but which are taken with a mini-osteometric board (MOB) have been developed by the lead author. Use of the MOB avoids the need to manipulate both the bone and calipers in three-dimensional space and causes less strain on the hands. However, the question of intra- and interobserver accuracy has not been adequately addressed for either set of measurements. The purpose of this study was to test both the Scheuer/Elkington and MOB measurements on 20 hands from 10 anatomical skeletons for intra- and inter-observer accuracy. The study found that 92% of the MOB measures had a lower intraobserver error, and 88% had a lower interobserver error than did the caliper measurements. It also found that the maximum midshaft diameter measurement used by Scheuer and Elkington is more repeatable than a mediolateral diameter. Overall, 88% of the 25 MOB measurements had median intraobserver error rates of under 1.5%, compared with 60% of the caliper measurements. Furthermore, the MOB measurements as a set were taken 10 to 12% faster than the caliper measurements.

Sex estimation from the talus in a Thai population.

Previous research on sex estimation from the tarsals has shown that the talus is the most sexually dimorphic tarsal bone in most populations. In order to assess the sexing potential of the talus in a Thai population, 252 skeletons (126 male, 126 female) from the Chiang Mai University Skeletal Collection were measured. The sample represents Thai people who come from the local Chiang Mai area and who died within the past ten years. Ten measurements were taken on the left and right tali from each skeleton. Seven of these measurements are similar, or identical, to measurements used by other researchers. Three experimental measurements were also taken. Logistic regression equations were calculated for each measurement, and for pairs of measurements. The individual measurements were also examined using ROC analysis. Averaging the results from both sides, the individual measurements with the highest correct allocation accuracies based on logistic regression analysis were trochlear length (88.2%), trochlear breadth (87.3%), talar length (85.5%), and inferior articular surface length (84.5%). The ROC results followed a similar pattern, with Area Under the Curve values as follows: trochlear length (0.952), inferior articular surface length (0.937), trochlear breadth (0.935), and talar length (0.914). When pairs of measurements were considered by means of logistic regression, four equations produced predicted allocation accuracies greater than 90% - three from the right talus, and one from the left. The highest accuracy on both sides resulted from a combination of the two most sexually dimorphic individual measurements of trochlear length and trochlear breadth. Together, they produced predicted allocation accuracies of 91.3% on the right side, and 91.4% on the left side. Unlike many past studies that have found talar length to be the most sexually dimorphic measurement of the talus, our study found trochlear length and breadth to be the most accurate measurements for distinguishing the sexes. Researchers developing sexing equations for use with other populations should consider including trochlear length and breadth in their analyses.

Use of 2D:4D digit ratios to determine sex.

Second to fourth digit ratios (2D:4D) are sexually dimorphic in human hands and established by the 13th gestational week. Application of 2D:4D for determining sex in living individuals by Kanchan et al. (Forensic Sci Int, 181, 2008, 53.e1) produced classification rates of 80% for males and 74-78% for females. Few studies have explored the use of 2D:4D for sexing skeletal remains. We test estimated finger lengths, phalanx lengths, and 2D:4D derived from hand bones for determining sex. Maximum phalanx length was collected using a mini-osteometric board from 451 individuals of known age, sex, and ancestry in four skeletal collections. Logistic regression of 2nd and 4th digit finger and phalanx lengths produced classification rates greater than 80%. Digit ratios, however, failed to reach classification rates greater than 59%. Our results support those of Voracek (Forensic Sci Int, 185, 2009, e29) and suggest that 2D:4D may be population-specific and thus inappropriate for universal application as a means of determining sex.

Determination of sex from the proximal hand phalanges in a Thai population.

A sample of 249 skeletons (154 males, 95 females) from the Chiang Mai University Skeletal Collection was studied to investigate the potential of proximal hand phalanges as indicators of sex among individuals from the Chiang Mai province of Thailand. The sample ranged in age from 19 to 93 years. Six measurements were taken on each proximal phalanx: maximum length, medio-lateral base width, antero-posterior base height, medio-lateral head width, antero-posterior head height and maximum mid-shaft diameter. The measurements were then subjected to ROC analysis as well as binary logistic regression to assess the relative correct allocation accuracy for each bone, and for different combinations of measurements from each bone. All proximal phalanges from both sides exhibited greater than 87% correct allocation accuracy for at least one logistic regression equation that included only two or three measurements. When the sample was limited to individuals with no missing measurements (n=209) in any of the phalanges, the most accurate equations for each proximal phalanx ranged from 87.6% to 92.3%, with the most accurate equation based on two measurements from the left 1st proximal phalanx, and the next most accurate from three measurements of the left 2nd proximal phalanx. The results suggest that proximal phalanges produce better allocation accuracies than metacarpals among modern individuals from Thailand.

Revised AMBER parameters for bioorganic phosphates.

We report AMBER force field parameters for biological simulations involving phosphorylation of serine, threonine or tyrosine. The initial parameters used RESP fitting for the atomic partial charges and standard values for all other parameters such as Lennard-Jones coefficients. These were refined with the aid of a thermodynamic cycle consisting of experimentally determined pKa values, solvation energies from molecular dynamics free energy simulations, and gas phase basicities from QM calculations. A polarization energy term was included to account for the charge density change between the gas-phase and solution, and solvation free energies were determined using thermodynamic integration. Parameter adjustment is required to obtain consistent thermodynamic results with better balanced electrostatic interactions between water and the phosphate oxygens. To achieve this we modified the phosphate oxygen radii. A thermodynamically consistent parameter set can be derived for monoanions and requires an increase of the van der Waals phosphate oxygen radii of approximately 0.09 Å. Larger, residue-specific radii appear to be needed for dianions. The revised parameters developed here should be of particular interest for environments where simulations of multiple protonation states may be of interest.

Sexual dimorphism in the tarsal bones: implications for sex determination.

An accurate determination of sex is essential in the identification of human remains in a forensic context. Measurements of some of the tarsals have been shown to be sexually dimorphic by previous researchers. The purpose of the present study is to determine which dimensions of the seven tarsals demonstrate the greatest sexual dimorphism and therefore have the most potential for accurate sex determination. Eighteen measurements of length, width, and height were obtained from the tarsals of 160 European-American males and females from the William M. Bass Donated Skeletal Collection. These measurements were made using a mini-osteometric board. Logistic regression analyses were performed to create equations for sex discrimination. All measurements showed significant sexual dimorphism, with the talus, cuboid, and cuneiform I producing allocation accuracies of between 88 and 92%. Combinations of measurements provided better accuracy (88.1-93.6%) than individual measurements (80.0-88.0%).

Determination of sex from the metacarpals in a Thai population.

Determination of sex using metacarpals was carried out on a sample of 249 skeletons from a Thai population (154 males and 95 females), ranging in age from 19 to 93 years. Six measurements were taken on each metacarpal, namely maximum length, medio-lateral base width, antero-posterior base height, medio-lateral head width, antero-posterior head height and mid-shaft diameter. Binary logistic regression equations were calculated for determining sex from these measurements. All metacarpals from both sides produced at least one equation that correctly allocated the skeletons with 80% or greater accuracy. In a comparative test using only individuals with no missing measurements (n=196), the most accurate equations for each metacarpal on the right side had pooled allocation accuracies ranging from 85.2% to 89.3%, with the best equation based on three measurements from the 5th metacarpal. On the left side, the most accurate equations for each metacarpal ranged from 83.2% to 89.8% correct allocation, with the best equation based on three measurements of the 2nd metacarpal. When the allocation accuracy for each sex is considered in addition to the pooled accuracy, the best equations involve the same three measurements of the 5th metacarpal on the right side, but shift to three measurements of the first metacarpal on the left side, with a pooled accuracy of 88.3%. The results of this study suggest that metacarpals can be used quite reliably for sexing in forensic contexts in Thailand.

Stature estimation from long bone lengths in a Thai population.

The estimation of stature is a very important step in developing a biological profile for forensic identification. However, little previous work has been done on stature estimation among modern Thai people, despite a growing number of forensic cases in Thailand in recent years. The current study was carried out on a sample of 200 skeletons from a northern Thai population (132 males and 68 females), ranging in age from 19 to 94 years. The maximum lengths of six long bones (humerus, radius, ulna, femur, tibia and fibula) were measured and stature reconstruction formulae generated using linear regression. These equations were then tested on a holdout sample of 15 females and 15 males. Results reveal that the three lower limb bones are the most accurate estimators of stature among the males, with the fibula equation producing the lowest standard error of the estimate (SE=4.89cm), followed by the femur (SE=5.06cm). Results for females were mixed. The femur produced the lowest standard error among the females (SE=5.21cm), followed by the radius (SE=5.63cm). However, when tested against the holdout sample (n=30), the femur equations were considerably more accurate, with a mean absolute error of 3.5cm and a median absolute error of 2.4cm. Females exhibited a higher standard error of the estimate than reported in many previous studies. This higher error may be the result of a recent secular trend in stature affecting the females of our sample somewhat more than the males.

Bipartite medial cuneiform: new frequencies from skeletal collections and a meta-analysis of previous cases.

Bipartition of the medial cuneiform is a malsegmentation defect of the foot characterized by separation of the normal cuneiform into dorsal and plantar segments. In many cases, these segments are held together by means of a cartilaginous or fibrocartilaginous bridge, resulting in a deep, lytic-like pit in dry bone reminiscent of those seen in cases of non-osseous tarsal coalition. Partial bipartition, where separation of the two segments is incomplete, may also occur. Though originally documented over 250 years ago, relatively little is known about the bipartite medial cuneiform. The purpose of this paper is to present thirteen new cases (ten complete, three partial) from Egypt, England, South Africa, Denmark, and the United States, and to analyze all known cases to investigate patterns in sex, laterality, frequency, and associated anomalies. Results suggest that bipartite medial cuneiforms are significantly more prevalent in males. Bipartite medial cuneiforms are also frequently bilateral, perhaps indicating a strong genetic component. Identification of this condition in multiple individuals from a cemetery could, therefore, suggest a familial relationship. Frequencies of this variant are consistently less than 1% in most large samples, and significant frequency differences among samples from around the world are rare. Several other minor congenital variations have been noted in individuals with bipartition of the medial cuneiform. However, additional systematic research is needed to elucidate further the prevalence of associated variants.

Dermatoglyphics from all Chinese ethnic groups reveal geographic patterning.

Completion of a survey of dermatoglyphic variables for all ethnic groups in an ethnically diverse country like China is a huge research project, and an achievement that anthropological and dermatoglyphic scholars in the country could once only dream of. However, through the endeavors of scientists in China over the last 30 years, the dream has become reality. This paper reports the results of a comprehensive analysis of dermatoglyphics from all ethnic groups in China. Using cluster analysis and principal component analysis of dermatoglyphics, it has been found that Chinese populations can be generally divided into a southern group and a northern group. Furthermore, there has been considerable debate about the origins of many Chinese populations and about proper assignment of these peoples to larger ethnic groups. In this paper, we suggest that dermatoglyphic data can inform these debates by helping to classify a Chinese population as a northern or southern group, using selected reference populations and quantitative methods. This study is the first to assemble and investigate dermatoglyphics from all 56 Chinese ethnic groups. It is fortunate that data on population dermatoglyphics, a field of physical anthropology, have now been collected for all 56 Chinese ethnic groups, because intermarriage between individuals from different Chinese ethnic groups occurs more frequently in recent times, making population dermatoglyphic research an ever more challenging field of inquiry.

An analysis of the placebo effect in Crohn's disease over time.

BACKGROUND: Randomized, placebo controlled trials are used to assess the efficacy of therapies for Crohn's disease. The placebo response and remission rates vary among studies. AIM: To analyse how the placebo response and remission rates in Crohn's trials have changed over time in the era of parenteral biologic therapies. METHODS: A search for randomized, placebo-controlled trials of parenteral biologic therapies for active Crohn's disease was conducted using online databases. The placebo response and remission rates and study week of evaluation were recorded for each trial. The placebo response and remission rates were analysed as functions of publication date and study week of evaluation. RESULTS: The odds of a placebo-induced remission and response significantly increased as the week of evaluation increased. The placebo remission rate increased significantly with year of publication. Adjusted for week of evaluation, this increase in placebo remission rate over time was no longer significant. The increase in the placebo response over this time period was not statistically significant. CONCLUSION: The observed increase in placebo remission rates over time in trials of parenteral biologic therapies in Crohn's disease is explained by longer times to the primary endpoint in more recent trials.

Sex determination from hand and foot bone lengths.

Numerous studies have addressed sex estimation from the hands and feet with varying results. These studies have utilized multiple measurements to determine sex from the hands and feet, including measures of robusticity (e.g., base width and midshaft diameter). However, robusticity measurements are affected by activity, which can disguise underlying patterns of sexual dimorphism. The purpose of this study is to investigate the utility of length measurements of the hands and feet to estimate sex. The sample consists of white females (n=123) and males (n=136) from the Terry Collection. Discriminant function analysis was used to classify individuals by sex. The left hand outperformed both the right hand and foot producing correct classification rates exceeding 80%. Surprisingly, the phalanges were better sex discriminators than either the metacarpals or metatarsals. This study suggests that length measures are more appropriate than robusticity measures for sex estimation.

Mice deficient in galectin-1 exhibit attenuated physiological responses to chronic hypoxia-induced pulmonary hypertension.

Pulmonary hypertension (PH) is characterized by sustained vasoconstriction, with subsequent extracellular matrix (ECM) production and smooth muscle cell (SMC) proliferation. Changes in the ECM can modulate vasoreactivity and SMC contraction. Galectin-1 (Gal-1) is a hypoxia-inducible beta-galactoside-binding lectin produced by vascular, interstitial, epithelial, and immune cells. Gal-1 regulates SMC differentiation, proliferation, and apoptosis via interactions with the ECM, as well as immune system function, and, therefore, likely plays a role in the pathogenesis of PH. We investigated the effects of Gal-1 during hypoxic PH by quantifying 1) Gal-1 expression in response to hypoxia in vitro and in vivo and 2) the effect of Gal-1 gene deletion on the magnitude of the PH response to chronic hypoxia in vivo. By constructing and screening a subtractive library, we found that acute hypoxia increases expression of Gal-1 mRNA in isolated pulmonary mesenchymal cells. In wild-type (WT) mice, Gal-1 immunoreactivity increased after 6 wk of hypoxia. Increased expression of Gal-1 protein was confirmed by quantitative Western analysis. Gal-1 knockout (Gal-1(-/-)) mice showed a decreased PH response, as measured by right ventricular pressure and the ratio of right ventricular to left ventricular + septum wet weight compared with their WT counterparts. However, the number and degree of muscularized vessels increased similarly in WT and Gal-1(-/-) mice. In response to chronic hypoxia, the decrease in factor 8-positive microvessel density was similar in both groups. Vasoreactivity of WT and Gal-1(-/-) mice was tested in vivo and with use of isolated perfused lungs exposed to acute hypoxia. Acute hypoxia caused a significant increase in RV pressure in wild-type and Gal-1(-/-) mice; however, the response of the Gal-1(-/-) mice was greater. These results suggest that Gal-1 influences the contractile response to hypoxia and subsequent remodeling during hypoxia-induced PH, which influences disease progression.

Os acromiale: population differences and their etiological significance.

The os acromiale is an accessory bone resulting from failure of the acromial apophysis to fuse to the scapula. It is a relatively frequent defect affecting 4-18% of most large skeletal series. The etiology of os acromiale is poorly understood, and two competing hypotheses have been proposed: (1) that the accessory bone represents a genetic defect, and (2) that it results from mechanical stress on the developing acromion. In order to assess the evidence for these two hypotheses, os acromiale frequencies from a South African cadaver sample (n = 494) were compared to frequencies from a medieval Danish archaeological sample (n = 532). The South African frequency (18.2%) was significantly higher than the medieval Danish frequency (7.7%, p < 0.0001). These results mirror those of another study comparing African- and Euro-Americans, and tend to support the genetic hypothesis. However, a left side bias (72%) was also found among the South Africans (p = 0.013), lending some support to the mechanical stress hypothesis. Sex and age biases were also examined but were not found. In order to further test the mechanical hypothesis, the medieval Danes were divided into groups of higher and lower socioeconomic status based upon cemetery type. Lower status individuals were presumed to have engaged in strenuous labor activities more often and at a younger age than higher status individuals. However, comparison of these two groups failed to demonstrate a significant frequency difference (p = 0.105). Based on the results of this study, it is suggested that a third etiology combining a genetic predisposition for os acromiale with mechanical stress as the proximate cause should also be considered.