InDEL instability in two different tumoral tissues and its forensic significance.

There may be cases where malignant tumor samples can be used for forensic DNA profiling studies. STRs are the first systems preferred in forensic science laboratories for identification purposes. However, genetic instability in tumoral tissues causes STR polymorphism to change, leading to erroneous results. On the other hand, insertion/deletion polymorphism (InDels) are used as genetic markers in forensic science, as they have features that make both STR and SNPs preferable. Although previous studies approved that STR instability is observed in many different tumors, there are only a few studies that have displayed the instability of InDels in tumoral tissues before. In this study, it was aimed to determine whether instability is observed in formalin-fixed paraffin-embedded breast and thyroid tumoral tissues at 36plex InDel Panel. A total of 47 cases, 26 of which were diagnosed as breast cancer and 21 as thyroid cancer, were included in the study. In 21 of 26 (80.76%) breast cancers mutational changes were observed, however only 6 of 21 (28.57%) thyroid carcinoma cases displayed instability.Moreover, in these six cases, mutations were detected at only 1 or 2 loci. The most common change in both tissues was loss of heterozygosity. These findings suggest that paraffin embedded tissues of thyroid tumor can be used in cases of forensic genetic identification, however paraffin embedded breast cancer tissues should be examined with care. In conclusion, low InDel mutation rates compared to STR instability, make InDel analysis from paraffin blocks suitable for forensic genetic identification. However, researchers should keep in mind that there may be differences between the profiles of the tumoral tissues taken as reference and the actual case. In addition, by incorporating additional markers such as SNPs and microhaplotypes with low mutation rates into the study alongside Indels, researchers can significantly enhance the discrimination power in identification processes.

Development of a multiplex panel with 36 insertion/deletion markers (InDel) for individual identification.

In recent years, the insertion/deletion (InDel) polymorphism has become a preferred genetic marker in forensic genetics due to its low mutation rates and small amplicon sizes. In this study, a 36-InDelplex identification panel, consisting of autosomal 34 InDel loci, 1 Y InDel locus, and amelogenin, was developed, and gene frequencies in the Turkish population were determined. The loci of the InDel panel with global minimum allele frequencies (MAF) ≥ 0.4 were selected from the 1000 Genomes Project Phase 3 data. The amplicon sizes of the loci were designed in the range of 69-252 bp. In the validation study of the developed panel, analysis threshold, dynamic range, sensitivity, stochastic threshold, inhibitor tolerance, and reproducibility parameters were studied by following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines. The sensitivity studies indicated that complete and reliable InDel profiles could be obtained with 0.25 ng of DNA. A population study was evaluated using 250 samples from Turkey. The mean observed heterozygosity ratio (Ho) of all loci was 0.48. The combined discrimination power (CPD) is 0.999999999990867 and the combined exclusion probability (CPE) was 0.9930. The population comparison was also made using Turkish and the five major populations from the 1000 Genomes Phase 3 populations' data (Africa, Europe, East Asia, South Asia, and America). In conclusion, the results showed that the 36-InDelplex panel is a reliable, sensitive, and accurate system that is suitable for human identification and population genetics purposes.

Technical note: A novel 3D scan-based optical method for analyzing lines drawn at different pen pressure.

Pen pressure is one of the important elements of handwriting and questioned document analysis which is also crucial to recognize forgery. In this paper, we present a new, non-contact, non-destructive, and relatively inexpensive technique to measure the width of the grooves made by the writing. Results demonstrate a clear difference in measured groove widths for varying pen pressure. The effect of passing a written or signed paper in different types of printers has also been studied. A clear decrease of the groove depth was noted when passing the document through a laser printer. An ink jet printer only resulted in a small decrease of the groove depth, while no effect could be detected from a dot matrix printer.

UVC-LED-based face mask design and efficacy against common germs.

During the Covid-19 pandemic, one of the best means of personal protection was using face masks. In this context, the World Health Organization has declared the attempts to produce masks inactivating airborne virus species a welcome initiative. This preliminary study aimed to prove that airborne germs passing through a mask filter cartridge can be destroyed by the rays emitted from UVC LEDs placed in such cartridge. We therefore designed such a face mask and tested the efficiency of UVC LEDs placed in its cartridge against common contaminants, gram-positive Staphylococcus aureus, gram-negative Pseudomonas aeruginosa, and the influenza A/Puerto Rico/8/1934 virus because of its similarity with SARS CoV-2. Eight UVC LEDs with a total power of 75 mW provided sufficient germicidal effect for all three germs. In terms of safety, ozone production released during UVC LED emission was negligible. Our findings are promising, as they show that well-designed UVC-based face masks can be effective against airborne germs, but further research on a greater sample may help us learn more and optimise such face masks.

Monitoring geographical differences in illicit drugs, alcohol, and tobacco consumption via wastewater-based epidemiology: Six major cities in Turkey.

A national wastewater-based epidemiology (WBE) monitoring campaign has been initiated to determine the trends in drug consumption in Turkey since 2019. This study aimed to present the wastewater monitoring results for four periods in 2019 for six major cities with 17 wastewater treatment plants. The study investigated heroin (HER), amphetamine (AMP), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA), cannabis, alcohol, and tobacco to understand the temporal and geographical drug consumption trends. The results indicated a trend of regular cannabis use in all the cities. Considering geographical variations, the drug usage trends were not homogeneous within the country for any of the investigated drugs, except cannabis. HER consumption was predominant in Denizli (1042.48 mg/1000 inh/day), while Izmir and Antalya (154.10 and 79.56 mg/1000 inh/day, respectively) topped for COC consumption. Aydin had the highest consumption levels of AMP (90.03 mg/1000 inh/day) and METH (358.13 mg/1000 inh/day), while MDMA consumption was the highest in Samsun (157.64 mg/1000 inh/day). Tobacco consumption was high in Aydin (8791.69 mg/1000 inh/day) and Antalya (5375.17 mg/1000 inh/day), whereas alcohol consumption was higher in Bursa than in the other cities (53434.61 mL/1000 inh/day). There were no statistically significant differences in the weekend consumption levels of the investigated drugs among these six cities. Although this study included the results of 1 year of consumption monitoring, the data confirms internationally published information on the drug trafficking routes of conventional drugs in this region, especially the Heroin-Balkan route. Results from further sampling will enable accurate evaluation of global drug consumption and trafficking, in addition to alcohol and tobacco use.

Prepared Disappearing Ink and Deciphering of Documents.

Disappearing inks can be used for forgeries in many fields. In this study, thymolphthalein indicator solution was prepared as a disappearing ink. A total of 54 different solutions containing thymolphthalein were prepared at six different concentrations and nine different pH values. Among the prepared solutions, 0.16 g/50 mL and 0.32 g/65 mL thymolphthalein at pH 14 were the optimum solutions that were not distinguishable from regular ink when applied to promissory note. Fountain pens were filled with the abovementioned ink solutions and applied to promissory notes for experimental purposes. After 40 h, ink residues were not visible on promissory notes written with the ink with the optimum pH (pH = 14) value. To decipher the entries that disappeared, an instrumental method (Video Spectral Comparator-8000) and a chemical method (using NH3 vapor) were used, succeeded at 0.32 g/65 mL, but failed at 0.16 g/50 mL thymolphthalein. Therefore, NH3 had to be sprayed for 0.16 g/50 mL with negligible harm.

Wastewater-based monitoring of illicit drug consumption in Istanbul: Preliminary results from two districts.

Wastewater-based epidemiology is a well-established and complementary approach for monitoring illicit drug use in the general population. In this study, amphetamine (AMP), methamphetamine (METH), 3,4-methylenedioxymethamphetamine (MDMA), cocaine (COC) (from benzoylecgonine), and cannabis (from THC-COOH) consumption levels were investigated for the first time in Turkey (Istanbul). A solid-phase extraction method was applied to influent wastewater samples collected from two districts, Beyoglu and Catalca. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was conducted with electrospray ionization in positive mode. Calibration curves were acquired in linear form with >0.999 correlation coefficients. Limit of detection levels were measured as 0.91-151 ng/L, and limit of quantitation levels were in the range of 3 to 500 ng/L. Solid-phase extraction recovery and repeatability experiments were achieved by spiking the mix solution to different concentrations (50, 250, 750 ng/L) in 50 mL tap water and wastewater (500, 1000 ng/L) samples in six replicates. The method was optimized, and recoveries were found to be over 80% for all six substances with up to 11.9% relative standard deviation. According to the real sample results, cannabis was found to be the most abused illicit substance among the analytes. The mean consumptions of the two districts, including seven consecutive days for AMP, METH, MDMA, COC, and cannabis, were found to be 27.2, 322, 331, 385, and 1224 mg/day/1000 inhabitants, respectively. In this presented study, all targeted compounds were analyzed simultaneously with the same analytical conditions. To the best of our knowledge, this report is the first to present illicit drug consumption data from Istanbul.

HLA B-27 subtypes in Turkish patients with spondyloarthropathy and healthy controls.

The frequency and the distribution of HLA-B27 subtypes in spondylarthropathy (SpA) patients and controls were investigated in a sample Turkish population. B27 subtyping was performed by PCR-SSP method in two groups: 49 unrelated HLA-B27 positive Turkish patients with the diagnosis of SpA according to the European Spondyloarthropathy Study Group Criteria, and 55 HLA-B27 positive healthy controls. The frequency of HLA-B*27 was 2.6% in the Turkish population, and B*2705 was the predominant allele among patients with SpA. The difference was mainly between male patients and male controls The proportion of B*2705 among B27-positive patients and controls was significantly different (P=0.02). Our study supports other reports from different populations which showed that B*2705 and B*2702 were more frequent in Caucasian patients with SpA.

Mutation rate at commonly used forensic STR loci: paternity testing experience.

Paternity tests are carried out by the analysis of hypervariable short tandem repeat DNA loci. These microsatellite sequences mutate at a higher rate than that of bulk DNA. The occurrence of germline mutations at STR loci posses problems in interpretation of resulting genetic profiles. We recently analyzed 59-159 parent/child allele transfers at 13 microsatellite loci. We identified 12 mutations in 7 microsatellite loci. No mutations were occurred in other 6 loci. The highest mutation rate was observed with 5 mutations at D8S1179 locus at different alleles. The event was always single repeat related. The mutation rate was between 0 and 1.5 x 10(-2) per locus per gamete per generation. The mutation event is very crucial for forensic DNA testing and accumulation of STR mutation data is extremely important for genetic profile interpretation.

Allele and haplotype frequencies of Y-short tandem repeat loci in Turkey.

AIM: To assess the frequency distribution of six Y-chromosomal specific short tandem repeat (STR) polymorphisms and frequencies of haplotypes in Turkish population. METHODS: Blood samples were taken from 200 unrelated Turkish men from different regions of Turkey, who were involved in legal proceedings concerning paternity. The DNA was amplified and typed by use of Y-Plex 6 kit containing 6 Y-STR markers (DYS393, DYS19, DYS389 II, DYS390, DYS391, and DYS385). Capillary electrophoresis was carried out on an ABI 310 Genetic Analyzer. RESULTS: Allele frequency profiles of the Turkish men showed no significant differences compared with previously published results for Swiss and German populations. The range of gene diversity was determined between 48.3% for DYS391 and 96.0% for DYS385. Of 184 determined haplotypes, 170 occurred once, and the rest more than once. The most common haplotypes had a frequency of 1.5%. CONCLUSION: High degree of haplotype diversity in Turkish population makes analysis of Y-STRs a useful tool in forensic cases.

Handwriting changes under the effect of alcohol.

Document examiners are often faced with difficulties in evaluating handwriting by persons under the influence of alcohol. Although numerous articles are available on the subject of alcohol influence on handwriting quality, most of them were based on empirical data such as "few" or "increased", without any statistical evaluation. The aim of this research is to determine whether previous observations on reported effects of alcohol on handwriting are valid and to establish the predictability of observing specific effects. A total of 73 participants, who completed all steps of the experiment, were surveyed. Handwriting samples were taken before and after the consumption of alcohol. The test form, including criteria of prior studies used by document examiners, was evaluated with the help of a Olympus X-Tr stereo microscope, direct and oblique angle lighting and a video spectral comparator (VSC 2000). Measurements were done by means of digital caliper, statistics using repeated measures ANOVA, Pearson correlation, Pearson Chi square test, McNemar test and Wilcoxon signed rank test. The results revealed that the handwriting parameters such as word lengths, height of upper and lower case letters, height of ascending letter, height of descending letter, spacing between words, number of angularity, number of tremor, and number of tapered ends are all significantly increased under the effect of alcohol. It was also determined that the significant correlation between the alteration of handwriting parameters such as height of upper and lower case letters, number of angularity, number of tapered ends and the amount of alcohol. Furthermore, it does not confirm the conclusions of previous studies stating that alcohol levels are not proper indicators. Our data strongly confirms that handwriting changes can be observed at any level of alcohol. None of the alterations in handwriting can be attributed to the effects of alcohol intake alone. However, the presence of some alterations together is strongly suggestive that the person was under the influence of alcohol. First of all, the duty of handwriting examiner is to identify if the questioned and known sample are coming from the same source. Consequently, as this explanatory analysis suggests that differences between sober and intoxicated persons can be identified in handwriting, but the examiner's judgement must be proportionately cautious, keeping in mind the abnormally wide range of variation.

Turkish population data on nine short tandem repeat loci: HumCSF1PO, HumTHO1, HumTPOX, HumFES/FPS, HumF13B, HumVWA, D3S1358, D7S820, D16S539.

Allele and genotype frequencies for the nine loci, HumCSF1PO, HumTHO1, HumTPOX, HumFES/FPS, HumF13B, HumVWA, D3S1358, D7S820 and D16S539 were determined using Silver STR III System on 223-598 unrelated Turkish individuals from different regions of the country.

Allele distribution data of nine short tandem repeat loci for Turkish population: D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820.

Allele and genotype frequencies for the nine loci D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820 were determined for 310 unrelated Turkish individuals.