Apichat Sinthubua

Gender differences in elements of human anterior commissure and olfactory bulb and tract.

To examine whether there were gender differences in the various brain regions, the authors investigated the gender differences in seven element contents of the anterior commissure, mammillary body, and olfactory bulb and tract by direct chemical analysis. After ordinary dissection at Nara Medical University was finished, the anterior commissures, mammillary bodies, and olfactory bulbs and tracts were resected from the cerebra cut at median line. The brain samples were treated with 99.5% ethanol three times to remove lipids. After ashing with nitric acid and perchloric acid, the seven element contents Ca, P, S, Mg, Zn, Fe, and Na were determined by inductively coupled plasma–atomic emission spectrometry. It was found that the Zn content was significantly higher in the anterior commissures of men than in those of women. In the olfactory bulbs and tracts, it was found that the Ca, P, and Zn contents were significantly higher in men than in women. In contrast, no significant difference was found between the mammillary bodies of men and women regarding the seven element contents.

The effect of physical activity, body mass index and waist circumference on incident diabetes

We read with interest the article by Edwards et al. [1] which evaluated the effect of physical activity, body mass index (BMI) and the normal range glycated hemoglobin on the incident diabetes. The questionnaire used in the study should have been highlighted with regard to its validation. It was also not mentioned if the questions were asked in English or any other language. A proper reference has to be cited in order to label the case as incident diabetes while considering the value of A1C or plasma glucose which was found to be missing. The authors mention that ‘there was no three-way interaction effects of physical activity, BMI and waist circumference (WC) on incident diabetes’ which is not well understood and debatable fact. In the present study, the duration or intensity of physical activity could have been measured in detail. Diabetes is an oxidative stress disorder and physical activity certainly relieves any such oxidative stress. Many factors such as diet, smoking or any other form of addiction, level of cholesterol and lipid profile, presence of hypertension should be ascertained in all the studied subjects. These may be confounding factors influencing the results. Interestingly, it is also important to have the lifestyle and history of the mental state of the individual which may predispose to incident diabetes. Genetic analysis of the subjects may prove to be more beneficial in order to estimate the incident diabetes. Overall, an interesting article. We congratulate the authors and thank the editor for publishing such an important study.

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.

Age estimation approaches using cranial suture closure: A validation study on a Thai population

Cranial suture closure, one of the most commonly used age estimation methods, for decades, however, is often viewed with caution and its reliability is still debated. Few methods of estimating age using the skeleton, especially cranial suture, have been tested on Thais. This study aims to test the traditional aging techniques using cranial suture closure on Thai individuals in order to identify the error rate of each method when applied to a Thai sample. Meindl and Lovejoy (1985), Acsádi and Nemeskéri (1970), and Mann (1991) methods were applied to 175 Thai dry crania. Bias and inaccuracy in the Meindl and Lovejoy, Acsádi and Nemeskéri, and Mann methods resulted in overestimation in young adults and underestimation in older individuals with an inaccuracy range of approximately 13-22 years. The Mann method approached 100% in predicting age in older males, but the method did not fare as well on Thai females. The results confirm inter-population variation does exist. Additionally, differences in age composition between populations used to develop the methods and Thais may lead to an increase in error. This study indicates that these three aging methods should be used in conjunction with other techniques. Further research which develops specific methods for Thais might give better results for age estimation.

Re: Cambareri et al.: Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared With Normal-weight Stone Formers? (Urology 2017;101:26-30)

We read with much interest the article entitled “Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared With Normalweight Stone Formers?” by Cambareri et al. At this juncture, we take this opportunity to express our scientific views on the published article. The authors aimed to determine if 24-hour urinary parameters in a pediatric age group with nephrolithiasis were influenced by body mass index (BMI). The authors stated the fact that prior studies did not find a relationship between pH and obesity in children unlike in adults. Interestingly, another recent study conducted on overweight and obese children also found that there was no association between urine pH and BMI. In contrast, in an earlier study, authors found a relation between increase in BMI and decreasing pH. There may be many reasons for such discrepancies in findings. An important cause may be a decrease in the urinary volume in different age groups. Proper history with regard to dietary intake of citrus fruits and vegetable products should be taken as these can alter the level of citrate in the urine. Level of sodium in any individual should also be investigated. In adults, osteopenia and osteoporosis are 2 important clinical conditions that are present with changes in calcium level, and these conditions may be absent in the pediatric age group. The duration of the study may be another important factor that may influence the results. The BMIs of children change over months and can also influence the results. Proper prenatal history on the intake of chemicals should be taken. The enzyme activity in the body of children may also be important. It would be noteworthy to observe the level of leptin, total cholesterol, and triglyceride as obesityrelated markers. Overall, this is an interesting article that may be important for clinicians. The authors and the editor need to be complimented for their genuine efforts in publishing an important article. Pasuk Mahakkanukrauh, M.D., Ph.D. Department of Anatomy Faculty of Medicine Chiang Mai University Chiang Mai, Thailand; Excellence Center in Osteology Research and Training Center (ORTC) & Forensic Osteology Research Centre Faculty of Medicine Chiang Mai University Chiang Mai, Thailand

Age estimation using aspartic amino acid racemization from a femur

Abstract Age estimation is an important step in post-mortem investigation, and the aspartic acid racemization (AAR) of dentin is the best tool for age estimation from human remains. However, teeth may not be found or sufficiently preserved to analyse the Dextro/Levo (D/L) ratio, and so age estimation using AAR from other organs, such as bones, is required. The current study evaluated age estimation methods using aspartic amino acid racemization from a femur in a Thai population. D/L ratio analysis using high-performance liquid chromatography (HPLC) was performed on 40 femoral bones from 24 males and 16 females, and the correlation between D/L ratio and age was 0.8316. The correlation coefficient in the male sample was greater than the female samples – 0.912 and 0.716, respectively. The standard error of estimation of all samples was 11.01 years. The correlation between the D/L ratio and the age of the total amino acid fraction from a femur was not as strong as from dentin and single protein purification, such as elastin and osteocalcin, but this method was necessary because teeth may not be found with body remains, and this method is not too complicated for routine forensic work.

A new method for sex estimation from maxillary suture length in a Thai population

Sex estimation is one of the crucial procedures in the biological profile identification of human skeletal remains. Knowing sex of unknown case can lead to accurate and appropriate methods for predicting age, stature, ancestry, or even personal identification. Skull is one of the most reliable one among other skeletons and it is usually retained for both archaeological and forensic contexts. Although many morphological features and metric measurements of skull have been studied for sexing, but to the best of our knowledge is no study on maxillary suture length for sex estimation. Therefore, this study aims to develop a new sex estimation method for a Thai population by determining three maxillary suture lengths: anterior, transverse, and posterior maxillary suture, by computerizing amount of pixel obtained from photographs of these sutures. The present study was conducted on 190 Thai bone samples of which 96 were males and 94 were females. Independent t test revealed statistically significant difference (P<0.01) between males and females in all maxillary suture measurements. Equations derived from prediction model, which required three maxillary suture lengths gave 76.8421% accuracy from the leave-one-out cross validation in estimating sex percentage accuracies in predicting sex from these equations, which were relatively moderate. This study provides a novel and objective sex estimation method for Thais. It suggests that maxillary suture length can be applied for sex estimation. The new computerized technique will contribute basis knowledge and method for sex estimation, especially when only base of skull is available in forensic circumstance.