Analysis of epigenetic clocks links yoga, sleep, education, reduced meat intake, coffee, and a SOCS2 gene variant to slower epigenetic aging

DNA methylation (DNAm) clocks hold promise for measuring biological age, useful for guiding clinical interventions and forensic identification. This study compared the commonly used DNAm clocks, using DNA methylation and SNP data generated from nearly 1000 human blood or buccal swab samples. We evaluated different preprocessing methods for age estimation, investigated the association of epigenetic age acceleration (EAA) with various lifestyle and sociodemographic factors, and undertook a series of novel genome-wide association analyses for different EAA measures to find associated genetic variants. Our results highlighted the Skin&Blood clock with ssNoob normalization as the most accurate predictor of chronological age. We provided novel evidence for an association between the practice of yoga and a reduction in the pace of aging (DunedinPACE). Increased sleep and physical activity were associated with lower mortality risk score (MRS) in our dataset. University degree, vegetable consumption, and coffee intake were associated with reduced levels of epigenetic aging, whereas smoking, higher BMI, meat consumption, and manual occupation correlated well with faster epigenetic aging, with FitAge, GrimAge, and DunedinPACE clocks showing the most robust associations. In addition, we found a novel association signal for SOCS2 rs73218878 (p = 2.87 × 10-8) and accelerated GrimAge. Our study emphasizes the importance of an optimized DNAm analysis workflow for accurate estimation of epigenetic age, which may influence downstream analyses. The results support the influence of genetic background on EAA. The associated SOCS2 is a member of the suppressor of cytokine signaling family known for its role in human longevity. The reported association between various risk factors and EAA has practical implications for the development of health programs to improve quality of life and reduce premature mortality associated with age-related diseases.

Do Intraoperative Platelet-Rich Plasma Injections Influence the Final Appearance of Vertical Scars after Breast Reduction? Spectrophotometric Analysis

Background: Platelet-rich plasma (PRP) has been shown to support wound healing and tissue regeneration due to its high concentration of growth factors and cytokines. This study aims to investigate the effect of intraoperative PRP injections on the final appearance of vertical scars after breast reduction, as well as to identify potential predictors of a scar's aesthetic assessment using spectrophotometric parameters. Methods: In this prospective, randomized trial, 82 scars from 41 women who underwent bilateral breast reduction with an inverted T pattern were analyzed. PRP or a placebo substance (0.9% sodium chloride solution) was injected intraoperatively into the edges of vertical wounds. Spectrophotometric measurements of scar pigmentation were performed 3 and 6 months after surgery; additionally, two independent observers evaluated the aesthetic appearance of scars based on photographs. Results: The results showed that the use of intraoperative PRP injections did not significantly influence the final appearance of vertical scars after breast reduction. Conclusions: We indicated spectrophotometric variables (b) in the early stages of wound healing (after 3 months) that can be predictors of the final scar's aesthetic outcome. This can be helpful in detecting scars that may need additional interventions to optimize the healing process.

Digit ratio and the femoral circumflex artery perforator: A sex-dependent association between the vascular system of the thigh and prenatal sex hormones?

BACKGROUND

The anterolateral thigh flap (ALTF) is a type of free flap which is commonly used in reconstructive surgery procedures and is based on the perforator from femoral circumflex artery. Some authors found that the location of the perforator differs between sexes.

OBJECTIVE

To verify the influence of prenatal sex hormones (as measured by 2D:4D) on the morphology of the perforator of the descending branch of the femoral circumflex artery.

METHODS

88 participants (43 women) of a mean age of 28.5 years (SD 8.1 years) had the following measurements performed: height and weight; right and left-hand 2nd and 4th fingers' lengths; and distance from anterior superior iliac spine to the perforator from descending branch of lateral femoral circumflex artery related to the thigh length (right and left) (AP ratio).

RESULTS

Right 2D:4D and Dr-l (right minus left 2D:4D) were dimorphic, similarly to AP ratio (right and left), which in women was significantly higher than in men. A significant correlation was found between right and left 2D:4D and location of the perforator of the left thigh in men. The higher right and left 2D:4D (more feminine) the higher the left AP ratio (more feminine).

CONCLUSION

Our findings suggest that the location of perforator of femoral circumflex artery may be influenced by prenatal sex steroids such that low prenatal testosterone and high prenatal oestrogen are correlated to high AP (lower branching of the artery).

Variability of anterolateral thigh flap perforator locations - clinical implications

<b><br>Introduction:</b> The anterolateral thigh flap is an example of a free flap widely applied for reconstruction of tissues within various areas of the body.</br> <b><br>Aim:</b> The aim of the study was to determine the most common locations of the ALT flap perforators in men and women as well as to clarify any potential differences in the location of the vessel in male vs. female subjects.</br> <b><br>Material and method:</b> In years 2021-2022, a study was conducted at the Plastic, Reconstructive, and Aesthetic Surgery Clinic in a group of 90 volunteers (45 women and 45 men, a total of 180 lower extremities) to determine the location of the anterolateral thigh flap perforator against the flap surface using a portable Doppler probe.</br> <b><br>Results:</b> Variable locations were revealed for the anterolateral thigh flap perforator within the study. In women, the perforator is located more distally from the anterior superior iliac spine, most frequently within the inferolateral quadrant, while being located closer to the anterior superior iliac spine, and most frequently within the superolateral quadrant, in men. No perforator was found in 3.3% of the examined limbs. No statistically significant differences were observed between the course of the perforators within the left and right lower limbs in individual patients.</br> <b><br>Conclusions:</b> The location of the ALT flap perforator is subject to sexual dimorphism, which facilitates the investigation area being narrowed down to the well-defined locations of its most frequent occurrence when planning anterolateral thigh flap reconstructive procedures.</br>.

Selected factors affecting the rate of reduction of body weight components during the first six months after bariatric surgery: A cohort study

<b><br>Aim:</b> To determine whether the rate of slimming following bariatric surgery depends on the sex, type of bariatric surgery, time elapsed since surgery or body weight components.</br> <b><br>Materials and methods:</b> The material is comprised of the results of three series of anthropometric measurements in 91 obese patients (before bariatric surgery, about 3 months after bariatric surgery and about 6 months afterwards). The inclusion criteria were patients of Polish origin admitted to the hospital from July 1, 2017 to January 31, 2019 for surgical treatment of obesity and written consent for the surgery and participation in the study. The measurements included body weight components assessed by bioelectrical impedance analysis.</br> <b><br>Results:</b> The reduction of all features was greater after SG than GB (p<0.0001), greater in the first quartile than in the second quartile after surgery (p<0.0001), and higher for fat mass than for other body weight components (p<0.0001). The sex of the patients, type of bariatric surgery, time elapsed since the operation, and type of body weight component constituted interactive modifiers of the rate of reduction.</br> <b><br>Conclusion:</b> After bariatric surgery, the reduction of fat mass was quicker in men than in women. SG and RYGB lead to a greater reduction of fat mass than GB. Among all three analyzed procedures, only for SG did the rate of body weight component reduction not decrease in the second quartile after surgery. This finding should be taken into account when creating an algorithm for treating a patient after bariatric surgery</br>.

Introduction of a multiplex amplicon sequencing assay to quantify DNA methylation in target cytosine markers underlying four selected epigenetic clocks

BACKGROUND

DNA methylation analysis has proven to be a powerful tool for age assessment. However, the implementation of epigenetic age prediction in diagnostics or routine forensic casework requires appropriate laboratory methods. In this study, we aimed to compare the performance of large-scale DNA methylation analysis protocols that show promise in terms of accuracy, throughput, multiplexing capacity, and high sensitivity.

RESULTS

The protocols were designed to target a predefined panel of 161 genomic CG/CA sites from four known estimators of epigenetic age-related parameters, optimized and validated using artificially methylated controls or blood samples. We successfully targeted 96% of these loci using two enrichment protocols: Ion AmpliSeq™, an amplicon-based method integrated with Ion Torrent S5, and SureSelectXT Methyl-Seq, a hybridization-based method followed by MiSeq FGx sequencing. Both protocols demonstrated high accuracy and robustness. Although hybridization assays have greater multiplexing capabilities, the best overall performance was observed for the amplicon-based protocol with the lowest variability in DNA methylation at 25 ng of starting DNA, mean observed marker coverage of ~ 6.7 k reads, and accuracy of methylation quantification with a mean absolute difference between observed and expected methylation beta value of 0.054. The Ion AmpliSeq method correlated strongly with genome-scale EPIC microarray data (R = 0.91) and showed superiority in terms of methylation measurement accuracy. Method-to-method bias was accounted for by the use of linear transformation, which provided a highly accurate prediction of calendar age with a mean absolute error of less than 5 years for the VISAGE and Hannum age clocks used. The pace of aging (PoAm) and the mortality risk score (MRS) estimators included in our panel represent next-generation clocks, were found to have low to moderate correlations with the VISAGE and Hannum models (R < 0.75), and thus may capture different aspects of epigenetic aging.

CONCLUSIONS

We propose a laboratory tool that allows the quantification of DNA methylation in cytosines underlying four different clocks, thus providing broad information on epigenetic aging while maintaining a reasonable number of CpG markers, opening the way to a wide range of applications in forensics, medicine, and healthcare.

Correlations between antimicrobial peptides and spectrophotometric skin color parameters in patients with basal cell carcinoma

BACKGROUND

Antimicrobial peptides (AMPs) are active molecules in the human innate immune system, that participate in host defense and regulate the inflammation process. Previous reports have confirmed that antimicrobial peptides play a critical role in carcinogenesis.

OBJECTIVE

The present study aimed to evaluate the correlations between plasma concentrations of AMPs and spectrophotometric parameters of skin color in patients with basal cell carcinoma and compare the results with those of healthy controls.

METHODS

The plasma concentrations of cathelicidin and beta-defensin-2 in 100 patients (50 with skin cancer and 50 healthy control subjects) were measured, and skin color parameters were tested using a DermaSpectrophotometer.

RESULTS

In patients with basal cell carcinoma, the concentrations of cathelicidin and beta-defensin-2 were significantly higher than those in healthy controls. In healthy control patients, when erythema increases, the levels of cathelicidin and beta-defensin-2 also increase. The direction of the relationship is opposite in people with basal cell carcinoma-the concentration of antimicrobial peptides decreases and the level of erythema increases.

CONCLUSION

A significantly higher level of plasma concentrations of cathelicidin and HBD-2 are correspondent to the presence of basal cell carcinoma. Skin cancer modifies the relationship between intensity of skin erythema and the levels of cathelicidin and HBD-2. This can be related to inadequate immunological response in patients with skin cancers. New direction of research may be pioneered in searching for cytokine or mast cells disorders.

The impact of exposure to tobacco smoking and maternal trauma in fetal life on risk of migraine

Introduction

Prenatal period is the key time in human development. Many prenatal factors are well-known and increase the risk of developing diseases' after birth. Few studies indicated the link between the prenatal period and the prevalence of migraine in childhood and adolescence so far. We decided to broaden current knowledge and investigate whether the prenatal factors influence the prevalence of migraine in adulthood. The objective of this study is to provide evidence of relationship between in utero environment and risk of migraine.

Methods

In total 266 females (136 in the migraine group, 130 in the control group) and 80 males (35 in the migraine group, 45 in the control group), aged 18-65 participated in the study. The quality of prenatal environment was characterized on the basis of mother's and father's education, tobacco smoke exposure, alcohol consumption, and traumatic event during pregnancy, which are considered as prenatal factors and affect on fetal development.

Results

Migraine occurrence in adulthood was significantly associated with maternal tobacco smoking during pregnancy (OR 3.42, 95% CI 1.54-7.61, p = 0.036) and traumatic event during pregnancy (OR 2.27, 95% CI 1.24-4.13, p = 0.020).

Discussion

Our study suggests that the fetal programming effect of tobacco smoking exposure and maternal trauma is not limited to prenatal life and is suggested as having a role in adulthood. Our findings support evidence that migraine adulthood can be partly influenced by early life conditions.

Digit ratio (2D:4D), laryngeal cancer and vocal fold leukoplakia

BACKGROUND

To date, there are no studies that have analyzed the possible influence of exposure to prenatal sex hormones on the risk of laryngeal cancer (LC) and premalignant laryngeal lesion-vocal fold leukoplakia (VFL). Digit ratio (2D:4D) is suggested to be a proxy of prenatal sex hormone exposure.

OBJECTIVE

To examine 2D:4D in patients with LC and clarify if it could add to the verified risk factors in estimating the overall risk of LC.

METHODS

511 subjects participated in the study. The study group included 269 patients: with LC (N = 114, 64 men) and VFL (N = 155, 116 men). Controls included 242 healthy individuals (66.40 ± 4.50 years (106 men)).

RESULTS

Predictive models estimating the risk of VFL and LC in women, based solely on predictors like smoking and alcohol consumption had a lower area under the ROC curve (AUC) than the model with left 2D:4D. AUC for the model estimating the likelihood of VFL increased from 0.83 to 0.85, and for LC from 0.76 to 0.79.

CONCLUSIONS

Low left 2D:4D may be associated with an increased risk of developing leukoplakia and laryngeal cancer in women. In the case of laryngeal cancer, left 2D:4D may serve as additional variable (to other known risk factors, such as smoking and/or alcohol consumption), which can improve cancer risk prediction.

DNAmFitAge: biological age indicator incorporating physical fitness

Physical fitness is a well-known correlate of health and the aging process and DNA methylation (DNAm) data can capture aging via epigenetic clocks. However, current epigenetic clocks did not yet use measures of mobility, strength, lung, or endurance fitness in their construction. We develop blood-based DNAm biomarkers for fitness parameters gait speed (walking speed), maximum handgrip strength, forced expiratory volume in one second (FEV1), and maximal oxygen uptake (VO2max) which have modest correlation with fitness parameters in five large-scale validation datasets (average r between 0.16-0.48). We then use these DNAm fitness parameter biomarkers with DNAmGrimAge, a DNAm mortality risk estimate, to construct DNAmFitAge, a new biological age indicator that incorporates physical fitness. DNAmFitAge is associated with low-intermediate physical activity levels across validation datasets (p = 6.4E-13), and younger/fitter DNAmFitAge corresponds to stronger DNAm fitness parameters in both males and females. DNAmFitAge is lower (p = 0.046) and DNAmVO2max is higher (p = 0.023) in male body builders compared to controls. Physically fit people have a younger DNAmFitAge and experience better age-related outcomes: lower mortality risk (p = 7.2E-51), coronary heart disease risk (p = 2.6E-8), and increased disease-free status (p = 1.1E-7). These new DNAm biomarkers provide researchers a new method to incorporate physical fitness into epigenetic clocks.

The 2D:4D index is associated with the development of excess body weight in adults, but not with the rate of weight loss following bariatric surgery

2D:4D finger length ratio is a proxy of prenatal sex hormone exposure. Prenatal testosterone decreases and prenatal estrogens increase this index. In the current study we investigated whether the 2D:4D index, as a marker of the prenatal hormonal environment, is associated with the development of overweight and obesity in adults, and whether is it correlated with the rate of weight loss in patients after bariatric surgery. We tested 125 adults with obesity (BMI ≥ 30.0 kg/m²), 125 adults with overweight (BMI 25.0–29.9 kg/m²) and 153 persons with normal body weight (BMI < 25 kg/m²) of both sexes. We have found that the development of excessive body weight in men and women, and fat accumulation in the upper arms, thighs and lower legs in women with obesity (but not men) are associated with increased prenatal estrogen exposure. This relationship indicates a new area of activity in the field of obesity prevention. Moreover, it seems that the 2D:4D index (especially of the right hand) may be a useful factor in early prediction of the risk of developing excessive body weight in humans. The rate of weight loss after bariatric surgery is independent of prenatal exposure to sex hormones.

Risk of Migraine in Europeans with Low Melanin Levels—A Population Based Case-Control Study

Populations with a relatively low concentration of melanin, e.g., inhabitants of Europe, North America, and Australia, are the most vulnerable to the harmful effects of UV radiation. Individuals with fair phototype are at greatest risk of developing skin cancer. Several neurological studies present that light skin may modify the risk of Alzheimer’s and Parkinson’s diseases. However, the relationship between migraine and skin pigmentation has not been investigated yet. The objective of this study is to provide evidence of the relationship between skin pigmentation and migraine prevalence in adults. We examined a group of 148 adults (33 men, 115 women) with migraine and a control group of 107 adults (43 men, 64 women). Parameters of skin pigmentation (melanin index, erythema index, CIElab, and RGB scales) were measured using a DSM II Cortex Technology dermospectrophotometer. Risk of migraine in lightly pigmented adults was elevated. Individuals with a low melanin index had over 3-fold increased risk of migraine (women: OR 3.53, men: OR 3.73). Fair phototype, which results from lightly pigmented skin, was associated with migraine prevalence. Migraineurs should take extra care to protect their skin from the negative effects of solar radiation.

Prenatal oestrogen-testosterone balance as a risk factor of migraine in adults

BACKGROUND

Migraine is a common neurological disease with extremely debilitating, but fully reversible symptoms. Women suffer from migraine more often than men. It was assumed that fluctuation of oestrogen level during menstrual cycle is one of many factors responsible for more frequent migraine attacks. The second-to-fourth digit ratio (2D:4D) is considered as an indicator of prenatal sex steroids. Balance of prenatal androgens (testosterone) and oestrogen has been studied in numerous diseases that are affected by hormones. However, the relationship between migraine and the sex steroids balance in prenatal development is still unexplained. The aim of this paper is to provide an evidence of relationship between prenatal oestrogen and testosterone exposure following 2D:4D digit ratio, and migraine prevalence in adults.

METHODS

We examined a group of 151 adults (33 males, 118 females) with migraine and a control group of 111 adults (45 males, 66 females). 2D:4D digit ratio of both hands was measured using sliding Vernier calliper.

RESULTS

Significant differences were found in the right hand. Female migraineurs had lower value of 2D:4D ratio than the control group and the right 2D:4D was lower than left 2D:4D (Δ2D:4D), suggesting prenatal testosterone dominance. The opposite relationship was observed in males. Male migraineurs had higher value of 2D:4D ratio and Δ2D:4D was greater than the control group, suggesting prenatal oestrogen dominance.

CONCLUSIONS

Our results suggest that depending on sex, different proportion of prenatal sex steroids might be a risk factor of migraine in adults. Women with migraine were presumably exposed in prenatal life to higher testosterone levels relative to oestrogen, while men with migraine were probably exposed in prenatal life to higher levels of oestrogen relative to testosterone.

Cortisol concentration affects fat and muscle mass among Polish children aged 6-13 years

Background

Cortisol is a steroid hormone acting as a stress hormone, which is crucial in regulating homeostasis. Previous studies have linked cortisol concentration to body mass and body composition.

Methods

The investigations were carried out in 2016–2017. A total of 176 children aged 6–13 years in primary schools in central Poland were investigated. Three types of measurements were performed: anthropometric (body weight and height, waist and hip circumferences), body composition (fat mass FM (%), muscle mass – MM (%), body cellular mass - BCM (%), total body water - TBW (%)), and cortisol concentration using saliva of the investigated individuals. Information about standard of living, type of feeding after birth, parental education and maternal trauma during pregnancy was obtained with questionnaires.

Results

The results of regression models after removing the environmental factors (parental education, standard of living, type of feeding after birth, and maternal trauma during pregnancy) indicate a statistically significant association between the cortisol concentration and fat mass and muscle mass. The cortisol concentration was negatively associated with FM (%) (Beta=-0.171; p = 0.026), explaining 2.32 % of the fat mass variability and positively associated with MM (%) (Beta = 0.192; p = 0.012) explaining 3.09 % of the muscle mass variability.

Conclusions

Cortisol concentration affects fat and muscle mass among Polish children.

Trial registration

The Ethical Commission at the University of Lodz (nr 19/KBBN-UŁ/II/2016).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02837-3.

Associations between second to fourth digit ratio, cortisol, vitamin D, and body composition among Polish children

Associations between body characteristics (body composition: fat mass, muscle mass, cell, and water mass as well as body proportion—BMI), the 2D:4D digit ratio, and the concentrations of cortisol and vitamin (25-OH)D among Polish children have not been studied before. A total of 133 (73 girls and 60 boys) healthy Polish children aged 7–11 years were examined. The investigation was divided into three parts: measuring (the length of the second and fourth fingers in both hands, body composition, and body height and mass), questionnaires (socioeconomic status), and laboratory investigations (25-OH vitamin D and cortisol concentrations in saliva measured with ELISA methods). Boys with digit ratios below 1 had lower vitamin D concentration than those with digit ratios equal to or higher than 1 (Z = − 2.33; p = 0.019). Only boys with the male-typical pattern of 2D:4D digit ratio tended to have a lower 25-OH vitamin D concentration in saliva. Thus, it might indicate an effect of prenatal programming on the concentrations of steroid hormones in later life. Neither vitamin D, 2D:4D digit ratio nor the cortisol level was associated with the body components or proportions. More studies are needed to evaluate the molecular and genetic background of this phenomenon.

Association Between rs12037447, rs146732504, rs151078858, rs55723436, and rs6094136 Polymorphisms and Kawasaki Disease in the Population of Polish Children

Background: Kawasaki disease (KD) is an acute self-limited febrile vasculitis that mainly affects young children. Coronary artery involvement is the most serious complication in children with KD. It is currently the leading cause of acquired cardiac disease in children from developed countries. Literature data indicate a significant role of genetic susceptibility to KD. Objective: The aim of this study was to perform the first Genome-Wide Association Study (GWAS) in a population of Polish children with KD and identify susceptible genes involved in the pathogenesis of KD. Materials and Methods: The blood samples of Kawasaki disease patients (n = 119) were collected between 2016 and 2020, isolated and stored at the Department of Pediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute in Warsaw. The control group was based on Polish donors (n = 6,071) registered as the POPULOUS collection at the Biobank Lab of The Department of Molecular Biophysics in University of Lodz. DNA samples were genotyped for 558,231 Single Nucleotide Polymorphisms (SNPs) using the 24 × 1 Infinium HTS Human Core Exome microarrays according to the protocol provided by the manufacturer. In order to discover and verify genetic risk-factors for KD, association analysis was carried out using PLINK 1.9. Results: Of all 164,395 variants, 5 were shown to occur statistically (p_adjusted < 0.05) more frequent in Kawasaki disease patients than in controls. Those are: rs12037447 in non-coding sequence (p_adjusted = 8.329 × 10^-4, OR = 8.697, 95% CI; 3.629-20.84) and rs146732504 in KIF25 (p_adjusted = 0.007354, OR = 11.42, 95% CI; 3.79-34.43), rs151078858 in PTPRJ (p_adjusted = 0.04513, OR = 8.116, 95% CI; 3.134-21.01), rs55723436 in SPECC1L (p_adjusted = 0.04596, OR = 5.596, 95% CI; 2.669-11.74), rs6094136 in RPN2 (p_adjusted = 0.04755, OR = 10.08, 95% CI; 3.385-30.01) genes. Conclusion: Polymorphisms of genes KIF25, PTRPJ, SPECC1L, RNP2 may be linked with the incidence of Kawasaki disease in Polish children.

Digit ratio (2D:4D) in women and men with lung cancer

A prenatal sex steroid environment of high prenatal testosterone and low prenatal oestrogen inhibits lung development and may predispose individuals to be vulnerable to lung disease in later life. Therefore, the aim of this report was to investigate whether there is an association between right and left 2D:4D (biomarker of prenatal sex steroids exposure) and primary lung cancer in women and men. Also, we considered the relationship between right–left 2D:4D (Δ2D:4D, a negative correlate of high prenatal testosterone and low prenatal oestrogen) and the age of lung cancer diagnosis. The study included 109 patients (61 men) with lung cancer and 197 controls (78 men). In the study we found that: (i) women with lung cancer have lower 2D:4D compared to controls (the effect was independent of smoking), (ii) among women with cancer, age at diagnosis was positively related to 2D:4D, i.e. women with masculinized 2D:4D present earlier with the cancer than women with feminized 2D:4D, (iii) among men with lung cancer, those with the most aggressive form (small-cell lung cancer) had masculinized (low) Δ2D:4D compared to those with the less aggressive form (non-small cell lung cancer). The data suggests that masculinized right 2D:4D and Δ2D:4D are associated with a predisposition to lung cancer and/or the more aggressive forms of lung cancer.

Body size measurements, digit ratio (2D:4D) and oestrogen and progesterone receptors' expressions in juvenile gigantomastia

Background Juvenile breast hypertrophy is characterised by massive enlargement of the breast in the peri-pubertal period. We aimed to analyse body size measurements (body mass index [BMI], waist-to-hip circumference ratio [WHR]), digit ratio (ratio of II and IV digits' length [2D:4D]) and oestrogen receptor (ER) alpha (ERα) and progesterone receptors (PRs) in the breast gland in women with juvenile gigantomastia. Methods The study involved 30 women (mean age 25.7 years) (mean age of onset - 14.8 years). ERα and PR expressions were detected immunohistochemically in breast gland samples. For comparison, 100 controls (50 women and 50 men) were included. Results BMI and WHR in women with gigantomastia were higher than in control women and the former had a higher WHR than expected for their BMI. 2D:4D in the examined women did not differ from that in control women. However, left 2D:4D was negatively related to the age of gigantomastia onset. There were no correlations between ER and PR expressions and the analysed body and digit ratios. Conclusions The lack of a relationship between 2D:4D and juvenile breast hypertrophy may suggest that foetal exposure to sex hormones may not be crucial in its aetiology. However, the link between high left 2D:4D and early development of gigantomastia suggests that prenatal sex hormones have a role in its development timing. High WHR, and particularly high WHR relative to BMI, may indicate that these women had at some stage of development higher circulating androgens, which may have been converted to oestrogens in breasts due to local aromatase activity. Verification of this hypothesis could allow consideration of the role of aromatase inhibitors in juvenile breast hypertrophy.

Association of saliva 25(OH)D concentration with body composition and proportion among pre-pubertal and pubertal Polish children

OBJECTIVES

Due to increasing problems with obesity and vitamin D deficiency among children, studies that tackle both problems together are needed.

METHODS

Data were collected from 182 randomly selected children aged 6-13 years in primary schools in central Poland. Measures included anthropometric dimensions, body composition, questionnaires completed by participants' parents, and saliva samples. The level of 25(OH)D was assessed from the saliva samples using an enzyme-linked immunosorbent assay kit. The children were divided into two groups: pre-pubertal (girls below 10 years and boys below 11 years) and pubertal individuals (girls above 10 years and boys above 11 years).

RESULTS

The 25(OH)D concentrations were higher in late spring (June) among pre-pubertal children than in the autumn (November-December) among pubertal children. The level of 25(OH)D was positively correlated with body cell mass (BCM,%) among all children (pubertal: R = 0.20, P = .044; pre-pubertal: R = 0.23, P = .041) and inversely associated with waist-to-hip ratio (WHR) among pubertal children of both sexes (R = -0.25; P = .031). The stepwise regression analysis revealed that investigation in spring (June) and breastfeeding was associated with increased muscle mass (MM, %) (beta = 0.253, P = .003 and beta = 0.225, P = .005, respectively) and total body water (TBW, %) (beta = 0.276, P = .004 and beta = 0.246, P = .011, respectively) and was associated with decreased body mass index (BMI; beta = -0.222, P = .024 and beta = -0.269, P = .009, respectively) and fat mass (%) (beta = -0.288, P = .003 and beta = -0.266, P = .005, respectively).

CONCLUSIONS

Season of salivary sampling and breastfeeding status were more strongly associated with body components, BMI and WHR, than 25(OH)D concentrations.

Familial factors more importantly modify the age of achieving motor developmental milestones than duration of breastfeeding amongst Polish children

Breastfeeding in the first year of life is an important factor that may modify the child's later development.The aim of this study was to examine the association between the duration of breastfeeding and the time of achieving motor development of Polish children taking into account their familial background. The study material comprised 460 individuals including 252 boys and 208 girls aged 9 to 56 months who were born at term (37-42 weeks) selected in years 1993-1997. The investigated dependent variables were: first attempts of sitting, standing and walking (months). The independent variables were divided into: explanatory variable - the duration of breastfeeding, and other covariates - birth weight, the paternal and maternal age at the time of childbirth, maternal tobacco smoking during and after pregnancy as well as the parental level of education. The results of regression models after removing the prenatal and familial factors did not indicate a significant relationship between the duration of breastfeeding and sitting up (F = 0.03, p = 0.8569), standing up (F = 0.79, p = 0.3741) and walking variability (F = 0.20, p = 0.6568) in studied group of children. The results showed that parental age and education may affect the offspring's gross motor development, though effect sizes are small and directions of influence vary between fathers and mothers. The study underlines the importance of familial factors over the breastfeeding duration impact on time of developmental milestones.

The association between socioeconomic status, duration of breastfeeding, parental age and birth parameters with BMI, body fat and muscle mass among prepubertal children in Poland

Objectives: We aimed to indicate simple determinants of abnormal body composition in children, such as socio-economic status (SES), duration of breastfeeding, parental age and birth parameters. Methods: The final data set consisted of 469 healthy prepubertal individuals (247 girls and 222 boys). We studied body mass, body height, and parameters of body composition such as muscle mass and fat mass. The birth parameters and gestational age were obtained from the children's medical record books held by the parents which were completed by medical personnel immediately following birth. Information about socio-economic status (SES), duration of breastfeeding and parental age was obtained by questionnaire. The statistical methods included forward multiple regression and generalized linear models (GLZ) or general linear model (GLM). Results: Higher fat mass (FM) (%) was connected with shorter duration of breastfeeding (< 2 months and lower SES (p < 0.05). Lower muscle mass (MM) (%) was linked with lower SES (p < 0.05) and lower birth weight (p < 0.05). Higher body mass index (BMI) was connected with higher birth weight (p < 0.05), shorter duration of breastfeeding (< 2 months) and lower SES (p < 0.05). Moreover interaction effects were observed in the case of the FM (%) (breastfeeding x SES; breastfeeding x parental age) and the BMI (breastfeeding x paternal age). Conclusions: Body composition can be linked with the duration of breastfeeding, SES, parental age, birth weight and birth length.

Second to fourth digit ratio (2D:4D) in women with carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS), a median nerve compressive neuropathy at the wrist, is the most common entrapment nerve disorder. Sex is an important risk factor of CTS as this condition is to five times more common in women than in men (sex-hormone dependent). There are no studies concerning 2D:4D (biomarker of prenatal sex steroids exposure) in patients with CTS.

AIM

Here we consider the relationship between 2D:4D and CTS in women.

STUDY DESIGN AND METHODS

The study involved 90 female participants (40 with a severe CTS (the mean age - 52.78 yrs., SD 11.44) and 50 control women (the mean age - 47.2 yrs., SD 8.23)). Anthropometric measurements were performed and the following indices were calculated: BMI, WHR and right and left 2D:4D.

RESULTS

A stepwise logistic regression model showed that higher WHR and lower right 2D:4D increase the risk of CTS in women (AUC = 0.8865).

CONCLUSIONS

These associations may suggest a role for prenatal and post-natal sex-hormones in CTS development, i.e. in the context of oestrogen receptor activation (number and/or sensitivity) and the pattern of fat distribution. Further studies examining the role of hormonal influence in this disorder may help to plan prophylaxis of CTS (e.g. early HRT).

Do skin and hair pigmentation in prepubertal and early pubertal stages correlate with 2D:4D?

OBJECTIVES

In most human populations women are less pigmented than men. However, before puberty, boys tend to have lighter skin than girls. Previous research has shown that skin pigmentation in European women is negatively correlated with digit ratio (2D:4D). Therefore, it has been hypothesized that skin pigmentation in females is partially controlled by prenatal hormones. The aim of this study was to examine the correlation between 2D:4D and pigmentation in girls and boys in the prepubertal or early pubertal stages of ontogenesis.

METHODS

The study group consisted of 598 Polish children (275 boys), aged 6.5-10.5 years. All underwent spectrophotometric measurements of skin and hair melanin index (SMI and HMI) and had the second and the fourth finger on both hands measured directly.

RESULTS

SMI (in girls) and HMI (in girls and boys) were positively correlated with age but 2D:4D was not. We regressed SMI and HMI on age and used the residuals as a measure of age-independent pigmentation. In girls, positive correlations were found between resSMI and 2D:4D for the right hand, but there was no correlation with left 2D:4D. In boys, resSMI did not correlate with 2D:4D. The resHMI was not related to 2D:4D in girls or boys.

CONCLUSION

Skin pigmentation in prepubertal or early pubertal girls is related to 2D:4D such that high 2D:4D is associated with higher pigmentation. This relationship may be mediated by the individual rate of sexual maturation.

Association of the 2D:4D digit ratio with body composition among the Polish children aged 6-13 years

The 2D:4D digit ratio is formed as a result of genetic factors but also prenatal exposure to sex hormones. The higher index value the higher concentration of the prenatal oestrogen. It is commonly known that testosterone is a hormone connected with muscle mass growth and that oestrogen affects adipogenesis. The aim of this study was to find if the digit ratio can be an informative indicator of the fat mass and muscle mass and body proportions in prepubertal children. Material and methods The analysed cohort included 420 children (221 girls and 199 boys) aged 6-13 years. Pearson's and Spearman's tests were conducted to assess whether 2D:4D was significantly correlated with the body composition measurements. Multiple regression models and stepwise forward regression were applied to select the most important independent variables affecting fat mass (%) and muscle mass (%) as well as the BMI and the WHR. Results The study shows that the digit ratio is negatively correlated with muscle mass (MM%) among girls (p < 0.05).There was no similar relationship in the group of boys. The regression models showed a significant role in determining the body composition and body proportions played by maternal factors such as: maternal level of education and weight gain during pregnancy. Conclusions The 2D:4D digit ratio seems to be an informative indicator of the muscle mass development since girls' early childhood. Moreover, maternal environment is also important in forming the offspring's body composition and proportions.

Resolution recovery for Compton camera using origin ensemble algorithm

PURPOSE

Compton cameras (CCs) use electronic collimation to reconstruct the images of activity distribution. Although this approach can greatly improve imaging efficiency, due to complex geometry of the CC principle, image reconstruction with the standard iterative algorithms, such as ordered subset expectation maximization (OSEM), can be very time-consuming, even more so if resolution recovery (RR) is implemented. We have previously shown that the origin ensemble (OE) algorithm can be used for the reconstruction of the CC data. Here we propose a method of extending our OE algorithm to include RR.

METHODS

To validate the proposed algorithm we used Monte Carlo simulations of a CC composed of multiple layers of pixelated CZT detectors and designed for imaging small animals. A series of CC acquisitions of small hot spheres and the Derenzo phantom placed in air were simulated. Images obtained from (a) the exact data, (b) blurred data but reconstructed without resolution recovery, and (c) blurred and reconstructed with resolution recovery were compared. Furthermore, the reconstructed contrast-to-background ratios were investigated using the phantom with nine spheres placed in a hot background.

RESULTS

Our simulations demonstrate that the proposed method allows for the recovery of the resolution loss that is due to imperfect accuracy of event detection. Additionally, tests of camera sensitivity corresponding to different detector configurations demonstrate that the proposed CC design has sensitivity comparable to PET. When the same number of events were considered, the computation time per iteration increased only by a factor of 2 when OE reconstruction with the resolution recovery correction was performed relative to the original OE algorithm. We estimate that the addition of resolution recovery to the OSEM would increase reconstruction times by 2-3 orders of magnitude per iteration.

CONCLUSIONS

The results of our tests demonstrate the improvement of image resolution provided by the OE reconstructions with resolution recovery. The quality of images and their contrast are similar to those obtained from the OE reconstructions from scans simulated with perfect energy and spatial resolutions.

Selected gene polymorphisms effect on skin and hair pigmentation in Polish children at the prepubertal age

SUMMARY

Background: Human pigmentation, similarly as many other biological features, changes in the course of post-natal ontogenesis, while in case of hair, pigmentation changes are more distinctive than in the skin or the iris. It is therefore extremely important to identify the genes, involved in the constitution of human pigmentation features at various stages of ontogenesis. Results of this type of analyses are of high practical significance in forensic study because they enable to create mathematical tools, allowing for prediction of the pigmentation phenotype, based on DNA studies. Aim: The objective of the investigation was finding out whether the genes, associated with pigmentation of adult subjects, differentiated in any way the newly forming pigmentation phenotype in Polish prepubertal children. Material and methods: The study encompassed Polish children, aged 7 to 10 years, without any abnormalities in skin or hair pigmentation. A total of 245 children were examined. Constitutive skin pigmentation according to skin melanin index (SMI) was evaluated, using a dermaspectrometer, and classified into three groups based on the reference values of 25 and 75 percentile for Polish children. Hair colors were evaluated by means of the descriptive Fischer-Saller scale and classified by a division of color variants (as accepted in that scale) (light blonde, blonde, dark blonde, brown and dark brown). In saliva samples, collected from the children, five (5) single nucleotide polymorphisms were identified: SNPs: rs1800401 (OCA2-15q11.2-q12), rs35264875 (TPCN2-11q13.3), rs16891982 (SLC45A2-5p13.2), rs12913832 (HERC2-15q13) and rs1805007 (MC1R-16q24.3). An association between each allele of verified genotype and skin and hair color phenotypes was assessed, using the z-statistic and associated p-value. The quality of classifiers was evaluated by 10-fold stratified cross-validation and was characterized by the area under the receiver operating characteristic curve (AUC). Results: Light skin pigmentation phenotype (SMI<25 percentile) was associated with rs1805007 (MC1R) (allelic OR=3.95; 95% Cl:1.20-12.99; p=0.0235), while the dark shade of the skin (SMI>75 percentile) with rs16891982 (SLC45A2) (allelic OR =14.37; 95% Cl: 1.78-115.88; p=0.0123). The probability of dark hair (brown and dark brown) in childhood was increased by T rs12913832 allele (HERC2) (OR=3.63); 95% Cl: 2.25-5.85; p < 0.0001) and dependent on it - rs1800401 (OCA2) (OR=6.31; 95% Cl: 1.74-22.91; p=0.0051). Other SNPs were not significantly associated with skin and hair color but improved prediction of these features. Conclusions: From the five gene polymorphisms analysed in Polish children the strongest correlation with hair color has the rs12913832 (HERC2) and with skin color - rs16891982 (SLC45A2). Therefore, the above-mentioned polymorphisms may be used as components of potential models, used to predict pigmentation features in European origin children in prepubertal age. To improve predictive value of the potential scoring model for hair color, the following should be additionally included: rs1800401 (OCA2), rs35264875 (TPCN2) and rs1805007 (MC1R), while for skin color: rs12913832 (HERC2) and rs1805007 (MC1R).

Parental smoking during pregnancy shortens offspring's legs

One of the most severe detrimental environmental factors acting during pregnancy is foetal smoke exposure. The aim of this study was to assess the effect of maternal, paternal and parental smoking during pregnancy on relative leg length in 7- to 10-year-old children. The research conducted in the years 2001-2002 included 978 term-born children, 348 boys and 630 girls, at the age of 7-10 years. Information concerning the birth weight of a child was obtained from the health records of the women. Information about the mother's and the father's smoking habits during pregnancy and about the mothers' education level was obtained from a questionnaire. The influence of parental smoking on relative leg length, controlled for age, sex, birth weight and the mother's education, as a proxy measure of socioeconomic status, and controlled for an interaction between sex and birth weight, was assessed by an analysis of covariance, where relative leg length was the dependent variable, smoking and sex were the independent variables, and birth weight as well as the mother's education were the covariates. Three separate analyses were run for the three models of smoking habits during pregnancy: the mother's smoking, the father's smoking and both parents' smoking. Only both parents' smoking showed a significant effect on relative leg length of offspring. It is probable that foetal hypoxia caused by carbon monoxide contained in smoke decelerated the growth of the long bones of foetuses.

Association of FTO and TMEM18 polymorphisms with overweight and obesity in the population of Polish children

The objective of the study was to verify whether or not FTO rs9939609, rs9926289 and TMEM18 rs4854344, rs6548238, rs2867125 variants are important risk factors for overweight and/or obesity in Polish children aged 6-16 (n=283). FTO rs 9939609 and rs9926289 exhibited a strong codominant obesity-predisposing effect of genotypes homozygous for minor alleles (OR=5.42, 95% CI: 2.04-14.39, p=0.0006). The important finding of the study is increased risk of overweight (OR=5.03, 95% CI: 1.15-21.93, p=0.0306) in individuals homozygous for the minor alleles rs4854344, rs6548238 and rs2867125 in the recessive inheritance model, while no other significant associations between TMEM18 variants and risk of obesity were found. Given the identified interaction TMEM18 genotype × BMI category (p=0.0077), it seems that the effect of homozygous for the minor alleles may be compared to a “weight guard”, which significantly increases the risk of overweight, but not of obesity, because it promotes weight gain only up to the threshold of obesity. Conclusion: The proposed hypothetical effect (“weight guard”) of homozygous for the minor alleles in the TMEM18 based on a rather small sample is a possible explanation of the effects of minor alleles, which minimize the risk of obesity.

Skin color parameters and Fitzpatrick phototypes in estimating the risk of skin cancer: A case-control study in the Polish population

BACKGROUND

Light skin pigmentation is a known risk factor for skin cancer.

OBJECTIVE

Skin color parameters and Fitzpatrick phototypes were evaluated in terms of their usefulness in predicting the risk of skin cancer.

METHODS

A case-control study involved 133 individuals with skin cancer (100 with basal cell carcinoma, 21 with squamous cell carcinoma, 12 with melanoma) and 156 healthy individuals. All of them had skin phototype determined and spectrophotometric skin color measurements were done on the inner surfaces of their arms and on the buttock. Using those data, prediction models were built and subjected to 17-fold stratified cross-validation.

RESULTS

A model, based on skin phototypes, was characterized by area under the receiver operating characteristic curve = 0.576 and exhibited a lower predictive power than the models, which were mostly based on spectrophotometric variables describing pigmentation levels. The best predictors of skin cancer were R coordinate of RGB color space (area under the receiver operating characteristic curve 0.687) and melanin index (area under the receiver operating characteristic curve 0.683) for skin on the buttock.

LIMITATIONS

A small number of patients were studied. Models were not externally validated.

CONCLUSIONS

Skin color parameters are more accurate predictors of skin cancer occurrence than skin phototypes. Spectrophotometry is a quick, easy, and affordable method offering relatively good predictive power.

Sensitivity estimation in time-of-flight list-mode positron emission tomography

PURPOSE

An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only.

METHODS

The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated.

RESULTS

The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data.

CONCLUSIONS

A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

Prenatal factors associated with the neonatal line thickness in human deciduous incisors

The neonatal line (NNL) is used to distinguish developmental events observed in enamel which occurred before and after birth. However, there are few studies reporting relationship between the characteristics of the NNL and factors affecting prenatal conditions. The aim of the study was to determine prenatal factors that may influence the NNL thickness in human deciduous teeth. The material consisted of longitudinal ground sections of 60 modern human deciduous incisors obtained from full-term healthy children with reported birth histories and prenatal factors. All teeth were sectioned in the labio-lingual plane using diamond blade (Buechler IsoMet 1000). Final specimens were observed using scanning electron microscopy at magnifications 320×. For each tooth, linear measurements of the NNL thickness were taken on its labial surface at the three levels from the cemento-enamel junction. The difference in the neonatal line thickness between tooth types and between males and females was statistically significant. A multiple regression analyses confirmed influence of two variables on the NNL thickness standardised on tooth type and the children's sex (z-score values). These variables are the taking of an antispasmodic medicine by the mother during pregnancy and the season of the child's birth. These two variables together explain nearly 17% of the variability of the NNL. Children of mothers taking a spasmolytic medicine during pregnancy were characterised by a thinner NNL compared with children whose mothers did not take such medication. Children born in summer and spring had a thinner NNL than children born in winter. These results indicate that the prenatal environment significantly contributes to the thickness of the NNL influencing the pace of reaching the post-delivery homeostasis by the newborn's organism.

Practical implementation of tetrahedral mesh reconstruction in emission tomography

This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio projection datasets. The results demonstrate that the reconstructed images represented as tetrahedral meshes based on point clouds offer image quality comparable to that achievable using a standard voxel grid while allowing substantial reduction in the number of unknown intensities to be reconstructed and reducing the noise.

Biometric characteristics of the pelvis in female-to-male transsexuals

The objective of the study was to evaluate the metric features of pelvises of 24 female-to-male (FtM) transsexuals as compared to control groups of 24 healthy males and 24 healthy females. The participants had their pelvises X-rayed with the same X-ray apparatus and in the same position. Seventeen measurements were taken on the basis of X-ray pictures of FtM transsexuals' pelvises and both comparison groups. Additionally, their body height was compared. The results showed that FtM transsexuals having female body height represent an intermediate size of three pelvic features and male values of five variables. In order to develop a model based on metric variables of the pelvis that would best discriminate the FtM transsexuals, the control females, and the control males, a discriminant analysis was applied. The model included four variables out of 17 metric features: the height of the pubic symphysis, the greatest pelvic breadth, the interischial distance, and the acetabular diameter. The model was found to be the best in discriminating males from females and FtM transsexuals, but considerably less effective in discriminating transsexuals from the two control groups. The results demonstrate that a number of FtM transsexuals' pelvic measurements reveal "masculinization," which confirms current results demonstrating a shift in the somatometric traits of transsexual females towards male traits. A discriminant analysis based only on pelvic metric features shows some differences between the size of the pelvis and chromosomal sex in FtM transsexuals, which might indicate a biological basis for gender identity disorder.

Tattooing and body piercing--what motivates you to do it?

BACKGROUND

Body ornamentation is becoming more and more popular, especially among young people.

AIMS

To establish the sociodemographic characteristics of people with tattoos or body piercing and to analyze the motivations for body ornamentation.

METHODS

The questionnaire studies were undertaken in Lodz--one of the largest cities in Poland. The data was collected from a group of 968 people, 476 of whom had a piercing and 492 a permanent tattoo.

RESULTS

Statistical analysis revealed that in the group of people with a tattoo, 36.8% were female and 63.2% were male. Contrary proportions were noted among people with a piercing: 78.8% female and 21.2% male.

CONCLUSIONS

Body piercing is significantly more popular among women while tattooing is more popular in men. Among adolescents, body piercing is performed considerably earlier than tattooing. The main reasons for body ornamenting in the Polish population are the desire to enhance one's individuality and the need to increase sexual attractiveness.

Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

Representation of photon limited data in emission tomography using origin ensembles

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detected events in a three-dimensional space and N is the number of detected events. The 3N-dimensional probability density function (PDF) for that ensemble is derived, and we present an algorithm for OE image estimation from tomographic measurements. A displayable image (e.g. grid based image) is derived from the OE formulation by calculating ensemble expectations based on the PDF using the Markov chain Monte Carlo method. The approach was applied to computer-simulated 3D list-mode positron emission tomography data. The reconstruction errors for a 10 000 000 event acquisition for simulated ranged from 0.1 to 34.8%, depending on object size and sampling density. The method was also applied to experimental data and the results of the OE method were consistent with those obtained by a standard maximum-likelihood approach. The method is a new approach to representation and reconstruction of data obtained by photon-limited emission tomography measurements.

Secular changes in the physical development of students of the Medical University of Łódź

This study analyses, using selected somatometric features, secular trend changes which have occurred over a quarter of a century in female and male students of the Medical University of Łódź. The study is based on the results of an anthropometric survey carried out among first-year students who commenced their studies in the academic years 1978/79 (240 females and 193 males), 1982/83 (347 females and 188 males), 1988/89 (178 females and 165 males) and 2003/04 (188 females and 77 males). The following features were examined in all participants in the survey: body height (B-v), the height of the lower body segment measured from a floor base to the crista iliaca at the point on the mid-axillary line (B-ic), shoulder width (a-a), intertrochanteric distance (tro-tro) and resting chest circumference. To compare average values Student's t-test was used with assumptions of equal and unequal variances. To gauge the magnitude of changes in specific features in the course of a quarter of a century a percentage difference in results was calculated for the years 2003/2004 and 1978/1979. The basis for the calculations was the initial value of a feature at the beginning of the period analysed. It was determined that in the 25-year period analysed (1978-2003) the young people commencing studies at the Medical University of Łódź exhibited an acceleration in the height of the lower body segment (B-ic) and of the intertrochanteric distance (tro-tro) and a deceleration in resting chest circumference. Additionally, an increase in shoulder width has been noted in female students; no significant intergenerational changes were noted in body height, although the last 15 years display certain symptoms of deceleration; there is an emerging tendency towards a blurring of the differences in body proportions between the sexes in the environment of the young people studying at the Medical University of Łódź.

Are body piercing and tattooing safe fashions?

The trend to ornamenting the human body by piercings and tattoos which is observed all over the world is becoming more and more popular. The aim of this research was to compare the frequency of complications occurring after piercing and tattooing and to analyze the conditions under which the procedures were performed. The research was based on the results of questionnaire studies performed in a group of 824 people (57.8% women and 42.2% men) aged 14-52. The data were compared by the fraction difference statistic test. The procedure was performed in professional establishments for 93.1% of people with piercings and 78.8% with tattoos. The difference between these fractions is statistically significant (p < 0.05). Complications were noted in 45.6% of people with piercings and 31.25% with tattoos. This difference is also statistically significant (p < 0.05). The people questioned with piercings noted mainly local infections, bleeding and tissue tearing, while subjects with tattoos mentioned pruritus and/or bleeding. We conclude that body piercing is connected with a higher risk of more serious complications than tattooing. There is a social awareness of this so piercing procedures are more often done in professional establishments.

[Developmental disturbances of medial part of face of patients with bilateral cleft lip and palate with special consideration of a nose]

Cleft is a developmental malformation, which is defined as a partial or complete lack of anatomic tissues continuity in typical areas of disorders in embryological face development. The reasons for cleft formation are not completely recognised but many hypotheses indicate both environmental and genetic factors as possible sources. The list of the cleft types is the following: cleft lip, cleft lip and alveolus, isolated cleft palate, cleft lip, alveolus and palate, and combined clefts. The malformation may occur unilateral or bilateral. According to World Health Organization cleft lip and palate is classified in the first ten of the most common developmental disorders, however the bilateral form of pathology is the least popular one.

MATERIAL AND METHODS

The aim of the study is the anthropometric measurement of a nose of children and adolescents with bilateral cleft lip, alveolus and palate in comparison with data gathered as a result of healthy people measurements. The research was conducted on 26 patients with the malformation: 12 girls and 14 boys at the age range between 7 and 18. The measurements were taken with the use of small bow and slide compasses. For the purpose of the statistical analysis we used formula for standardisation. Both, the arithmetic average and the standard deviation were estimated on the basis of research done on 30 healthy people of same sex and at proper age. Intersexual comparison of these values with the use of t-Student test was done. In order to distinguish homologues features in respect to the comparative group, one-way ANOVA and test post hoc (Duncan) were used.

RESULTS

Malformation was mainly reflected in increased width the base of the nose (sbal-sbal), width of nose (al-al) and its small prominence (sn-prn). Increase in head height values together with underdevelopment in sagittal plane was also observable. The increase of upper face height (n-sto) was recognized as stronger in case of females than males with the same malformation. The middle part of face was characterized by increase of height measurements together with sagittal plane underdevelopment.

CONCLUSIONS

It was stated that the patients with bilateral cleft lip, alveolus and palate tended to have flat and wide nose.

[Analysis of nose growth]

INTRODUCTION

During the last few decades the meaning of anthropometric methods has increased. Many medical disciplines use measurements of human body in clinical diagnosis, treatment planning and determining the best time for operation. In Polish literature current norms for nose development do not exist, however nose is particulary often the subject of corective, reconstructive and even creative operations. The aim of this review is metric description of the characteristic features and proportions of the nose in both gender among persons, who were 4, 14, 18 and 25 years old. Also we wanted to describe how advanced was development of the nose in each age group and when it finished its evolution.

MATERIAL AND METHOD

We have invastigated 240 persons (60 persons in each age group - 4, 14, 18, 25 years old). To this review we have clasiffied children and adults without any malformations or post-traumatic disfigurments of the face, including nose. We have analysed 10 anthropometric features and than we have calculated 10 proportion indexes. We have taken those measurements according to Martin's technics.

RESULTS

We have confirmed that most of features (without width of the nose basis) indicate statistically characteristic growth between 4 and 14 years old in both gender. Until 18 years old length of the nose foramens and width of the nasal septum in girls and length of the nose foramens and nasal tip protrusion in boys are growing. After 18 years old we have not seen any others essential changes. Also we have noticed that growth potential of nose parts is inverse proportional to the degree of nose development in the beginning of ontogenesis.

CONCLUSIONS

We suggest that any cosmetic operations of nose should be done after 18 years old.