Exploring heart dissection techniques for enhancing anatomical education: a pilot study to replicate transthoracic echocardiography.

PURPOSE: For novice learners, converting two-dimensional (2D) images of echocardiography to three-dimensional (3D) cardiac structures is deemed challenging. This study aimed to develop an accurate dissection method of the heart to reproduce the transthoracic echocardiographic views on cadavers and elucidate new educational methods in human anatomy dissection courses. METHODS: A total of 18 hearts were used in this study. After reflecting the anterior thoracic wall inferiorly, the hearts were excised from embalmed cadavers. Thereafter, three landmarks were set on the heart for each plane of the incision, and the hearts were incised to observe the three different echocardiographic views, which include the apical four-chamber view (A4C), parasternal long axis (PLAX) view, and parasternal short axis (PSAX) view at the papillary muscle level. If all structures for observation during routine echocardiography are clearly observed in each view, a successful incision is considered. All procedures and incisions were performed by the medical students. After a successful incision, hearts were returned to the original position in the pericardial sac for further observation. RESULTS: The success rates of incision for each view were 83.3% (5/6 success cases), 83.3% (5/6 success cases), and 66.7% (4/6 success cases) in the A4C view, PLAX view, and PSAX view at the papillary muscle level, respectively. CONCLUSION: This dissection method could probably be employed to reproduce transthoracic echocardiographic views on cadaveric hearts, which is beneficial for novice learners for a deeper understanding of the anatomy.

The interrelationship between three-dimensional foot mobility and bodyweight bearing.

[Purpose] To clarify the three-dimensional nature of foot mobility and its interrelationships within the foot due to bodyweight bearing. [Participants and Methods] Data regarding left foot mobility due to body weight bearing were collected from 31 healthy adults. Foot shape differences while sitting and standing, and their interrelationship were examined. The same examiner reapplied the landmark stickers when misaligned during measurement position changes. [Results] The foot length, heel width, forefoot width, hallux valgus angle, and calcaneus eversion angle were significantly larger in the standing than in sitting position. The digitus minimus varus angle was significantly smaller in the standing than in sitting position. The medial and lateral malleoli, navicular, and dorsum of the foot were displaced medially and inferiorly; the other indices, except for the midfoot, were displaced anteriorly. The interrelationships within the foot showed a positive correlation between the calcaneus eversion angle and the medial displacement of the medial and lateral malleoli, navicular, and dorsum of the foot points. There was a negative correlation between the calcaneus eversion angle and inferior displacement of the medial malleolus, navicular, and dorsum of the foot. [Conclusion] The intra-foot coordination relationship in response to bodyweight bearing was clarified.

Microenvironment for spermatogenesis and sperm maturation.

The male reproductive system consists of testes, a series of ducts connecting the testes to the external urethral orifice, accessory sex glands, and the penis. Spermatogonial stem cells differentiate and mature in testes and epididymides, and spermatozoa are ejaculated with exocrine fluids secreted by accessory sex glands. Many studies have clarified the detailed structure and function of the male reproductive system, and have shown that various biologic controls, including genomics, epigenetics, and the neuroendocrine-immune system regulate proliferation, differentiation, and maturation of germ cells. In other words (1) genetic deletion or abnormalities, (2) aberration of DNA methylation and histone modifications, as well as small RNA dysfunction, and (3) neuroendocrine-immune disorders are involved in functional failure of the male reproductive system. In this article, we review these three factors for germ cell microcircumstance, especially focused on the immunoendocrine environment. In particular, the relation between factors protecting germ cells with strong auto-immunogenicity and opposite factors compromising this protection are discussed. Reductions in sperm count, concentration, and semen quality are serious problems in developed countries, although the causes are complex and remain unclear. The accumulation of basic knowledge regarding the structure, function, and regulation of the male reproductive system under various experimental conditions will be important to resolve these problems.

Neonatal maternal separation causes decreased numbers of sertoli cell, spermatogenic cells, and sperm in mice.

Neonatal maternal separation is an experimental model used to evaluate the effects of toxic stress in neonates, or early life stress. Although various physiological and psychological stresses during childhood have been reported, the effects of neonatal maternal separation on the male reproductive system remain unclear. Therefore, the present study evaluated the effects of neonatal maternal separation on the male reproductive system. In neonatal male ICR mice, maternal separation was performed for 0.5, 1, 2, and 4 hours/day, from postnatal day 1 to 10. At 10 weeks of age, the neonatal maternal separation mice exhibited decreases in both testicular weight and epididymal sperm number, along with various testicular morphological changes involving germ cells, Sertoli cells, and interstitial cells. Notably, neonatal maternal separation mice showed decreased numbers of Sertoli cells. Animals subjected to 0.5-, 1-, and 2-h/day neonatal maternal separation exhibited decreases in serum levels of testosterone but not in those of gonadotropin (luteinizing hormone and follicle-stimulating hormone). Together, these data showed that neonatal maternal separation in male mice causes decreased Sertoli cell numbers following puberty, resulting in subsequent decreased spermatogenic activity.

Evaluation of Yanagihara facial nerve grading system based on a muscle fiber analysis of human facial muscles.

PURPOSE: We morphometrically analyzed human facial muscles, and evaluated the Yanagihara facial nerve grading system using our data. METHODS: We used 15 types of human facial muscle, 2 types of masticatory muscle and 2 types of skeletal muscle. The materials were obtained from 11 Japanese male cadavers aged 43-86 years. We counted the muscle fibers and measured the transverse area of the muscle fibers (TAMF), and then calculated the number of muscle fibers (NMF) per mm2 and the average TAMF. RESULTS: We found a significant correlation between average TAMF and NMF (r = - 0.70; p < 0.01). We classified facial muscles into three types based on the correlational results. Type A had a low average TAMF and high NMF. Type C had a high average TAMF and low NMF. Masticatory and skeletal muscles were characterized as Type C. Type B was intermediate between Types A and C. CONCLUSIONS: Pathological changes in the facial muscles in facial nerve palsy seem to vary according to the type of facial muscle, because each facial muscle has a unique fiber-type composition. As the nine discrete facial expressive states evaluated in the Yanagihara system involve all three facial muscle types of our classification, the Yanagihara system is an outstanding system for grading facial nerve palsy in terms of the facial muscle morphology.

The methylation levels of the H19 differentially methylated region in human umbilical cords reflect newborn parameters and changes by maternal environmental factors during early pregnancy.

H19 is a tumor-suppressor gene, and changes in the methylation of the H19-differential methylation region (H19-DMR) are related to human health. However, little is known about the factors that regulate the methylation levels of H19-DMR. Several recent studies have shown that maternal environmental factors during pregnancy, such as smoking, drinking, chemical exposure, and nutrient intake, can alter the methylation levels of several genes in fetal tissues. In this study, we examined the effects of maternal factors on changes in the methylation levels of H19-DMR in the human umbilical cord (UC), an extra-embryonic tissue. Participants from the Chiba study of Mother and Children's Health (C-MACH) were enrolled in this study. Genomic DNA was extracted from UC samples, and the methylation level of H19-DMR was evaluated by methylation-sensitive high resolution melting analysis. Individual maternal and paternal factors and clinical information for newborns at birth were examined using questionnaires prepared in the C-MACH study, a brief-type self-administered diet history questionnaire (BDHQ) during early pregnancy (gestational age of 12 weeks), and medical records. Univariate and multivariate logistic regression analyses indicated that reduced H19-DMR methylation (<50% methylation) in UC tissues was positively related to decreased head circumference in newborns [odds ratio (OR) =2.82; 95% confidence intervals (CI): 1.21-6.87; p=0.0183 and OR =2.51; 95% CI: 1.02-6.46; p=0.0499, respectively]. Moreover, multiple comparison test showed that H19-DMR methylation in UC tissues was significantly reduced in the low calorie group (intake of less than 1,000kcal/day; methylation level: 40.98%; 95% CI: 33.86-48.11) compared with that in the middle (1,000-1,999kcal/day; methylation level: 51.28%; 95% CI: 48.28-54.27) and high (≥2,000kcal/day; methylation level: 52.16%; 95% CI: 44.81-59.51) calorie groups (p=0.0054 and 0.047, respectively). In the subpopulations with low to moderate calorie intake (<2,000kcal/day), reduced H19-DMR methylation in UC tissues was significantly related to serum homocysteine concentration (OR =0.520; 95% CI: 0.285-0.875; p=0.019), maternal age (OR =1.22; 95% CI: 1.01-1.52; p=0.049), and serum folate levels (OR =0.917; 95% CI: 0.838-0.990; p=0.040). These data indicated that H19-DMR methylation levels in human UC tissues could be modulated by maternal factors during early pregnancy and may affect fetal and newborn growth.

Changes in expression levels of oxidative stress-related genes in mouse epididymides by neonatal exposure to low-dose decabromodiphenyl ether.

Decabromodiphenyl ether (decaBDE), one of the polybrominated diphenyl ethers (PBDEs), is the most well-known flame retardant and is used worldwide. In a previous study, we identified adverse effects of neonatal decaBDE exposure on mouse epididymides, such as decreased epididymal weight. On the other hand, neonatal exposure to diethylstilbestrol (DES), an artificial estrogenic compound, also causes several adverse effects on epididymides. DES exposure results in decreased epididymal weight, morphological abnormalities, and permanent alterations in the expression levels of several genes. The molecular mechanisms underlying the harmful effects of decaBDE exposure remain unclear. Many studies have reported that PBDEs have estrogenic activity, which may contribute to the induction of the adverse effects of decaBDE exposure. We aimed to examine the effects of neonatal decaBDE exposure on epididymides. Our data showed that (1) no histological change was observed on epididymal tissues from neonatal decaBDE exposure, unlike the effect of DES, (2) decaBDE exposure did not induce the alterations in gene expression observed with DES exposure; instead alterations in gene expression of certain oxidative stress-related genes were observed, and (3) the expression of ubiquitin C increased in decaBDE-exposed mouse epididymides. Our present data suggest the possibility that increased oxidative stress plays a role in the harmful effects observed in mouse epididymides after decaBDE-exposure.

Histological differences between the central and peripheral areas of the testes of busulfan-administered mice.

Busulfan is an anticancer drug known to cause serious damage to seminiferous tubules in the testes and deplete germ cells in human and animal models. The testicular artery is anastomosed with deferential and cremasteric arteries and is divided into capsular arteries, which give rise to the centripetal arteries and then recurrent arteries. The arterial blood in the testicular tissue is supplied by such a consequent system of arterial vessels, in order from the peripheral to the central area. As anticancer drugs are generally distributed throughout the whole body via the bloodstream and the running and distribution of arteries differ among the testicular areas, we hypothesized that the efficacy of busulfan differs in different testicular areas, particularly between the central and peripheral areas. In this study, busulfan was intraperitoneally injected at 40 mg/kg body weight into C57BL/6J male mice. After 28 days, in busulfan-treated mice, the diameters of seminiferous tubules were significantly higher in the central than in the peripheral area of the testes. The seminiferous tubular areas also significantly decreased in the peripheral areas compared with the central areas. The number of germ cells per seminiferous tubule was significantly higher in the central than in the peripheral area. Sertoli cell nuclei were detached into the lumen in the peripheral area. The number of Leydig cells was significantly lower in the peripheral areas. These data suggest that the effects of busulfan differ between the central and peripheral areas of the testis at 4 weeks after busulfan administration.

Effects of female bone marrow transplantation on male reproductive organs.

Graft-versus-host disease (GVHD), an adverse effect after bone marrow transplantation (BMT), may affect male reproductive function. It is hypothesized that a sex-mismatched BMT induces GVHD in male reproductive organs because female immune cells are not immunologically tolerant to specific antigens of the male organs. However, this hypothesis has not been experimentally verified using male (M) recipient animals following BMT from the female (F) donors. Therefore, the aim of the present study is to examine whether the female BMT to males (F→M group) induces some GVHD reactions in the testis and the other male reproductive organs. The results showed that no inflammation was found in recipients of the male BMT to males (M→M group), whereas significant inflammatory cell responses lasting for at least 4 months were induced in testis, epididymis, prostate and preputial gland in some mice of F→M group. The most severe lesion was found in the preputial gland, in which lymphocytic inflammation was accompanied by loss of glandular acini, thickening of the interstitum and increased cytokines such as TNF-α and IFN-γ. Western blot analyses revealed that sera from the F→M group reacted with various antigens of the male reproductive organs. These results indicate that transplanted female immune cells may recognize the male reproductive organs as immunologically foreign ones and induce chronic GVHD, which may affect male reproductive function.

Effects on the local immunity in the testis by exposure to di-(2-ethylhexyl) phthalate (DEHP) in mice.

Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been reported to induce spermatogenic disturbance through oxidant stress and affect the immune system as an adjuvant. However, the effect of DEHP on the testicular immune microenvironment has not yet been investigated. In the present study, we examined the testicular immune microenvironment after exposure to doses of DEHP, previously identified as no-observed-adverse-effect levels. Adult male mice were administered food containing 0%, 0.01% or 0.1% DEHP and then testes were analyzed. The results showed that a slight but significant spermatogenic disturbance appeared in the 0.1% DEHP group but not in the 0.01% DEHP group at 8 weeks. It was also demonstrated that lymphocytes and F4/80- and MHC class II- positive cells were significantly increased with the elevation of IL-10 and IFN-γ mRNA expressions in the testes of not only the 0.1% DEHP group but also the 0.01% DEHP group at 8 weeks. Histochemical analyses involving horseradish peroxidase (HRP) as a tracer showed that a little blood-borne HRP had infiltrated into the lumen of a few seminiferous tubules beyond the blood-testis-barrier in both the 0.1% and 0.01% DEHP groups at 8 weeks. This indicates that a dose of DEHP that has little effects on spermatogenesis can change the testicular immune microenvironment with functional damage of the blood-testis barrier.

Cadmium exposure increases susceptibility to testicular autoimmunity in mice.

Cadmium, one of various environmental toxicants, is known to suppress systemic immunity and to injure the testicular capillary endothelia with resultant necrosis of testicular tissues in mice and rats treated with high doses. Recently, it also became evident that cadmium can affect the integrity of the blood-testis barrier (BTB), the endocrine function of Leydig cells, apoptosis of germ cells and systemic immunity, even on treatment with a low dose that does not induce spermatogenic disturbance. Experimental autoimmune orchitis (EAO), i.e., an organ-specific autoimmunity of the testis, can be induced by repeated immunization with testicular antigens, and its pathology is characterized by lymphocytic inflammation and spermatogenic disturbance. In the present study, we investigated the morphological and functional changes of testes in mice treated with a low dose of cadmium chloride (CdCl2 ) and also examined its toxicity as to susceptibility to EAO. The results showed that exposure to 3 mg CdCl2 kg(-1) body weight did not affect the spermatogenic state. However, the BTB at the tubuli recti and the rete testis, but not the seminiferous tubules, was slightly weakened, and intra-testicular mRNA expression of interleukin (IL)-6, tumor necrosis factor-α and IL-1ß was significantly increased by the CdCl2 treatment. Furthermore, immunization with testicular antigens after the CdCl2 exposure significantly augmented the EAO severity. Therefore, exposure to a low dose of CdCl2 induces no significant disturbance of spermatogenesis, however, it does change the immunological microcircumstances in the testis, resulting in increased susceptibility to testicular autoimmunity.

Development of a non-invasive method for testicular toxicity evaluation using a novel compact magnetic resonance imaging system.

In non-clinical animal studies for drug discovery, histopathological evaluation is the most powerful tool to assess testicular toxicity. However, histological analysis is extremely invasive; many experimental animals are needed to evaluate changes in the pathology and anatomy of the testes over time. As an alternative, small animal magnetic resonance imaging (MRI) offers a non-invasive methodology to examine testicular toxicity without radiation. The present study demonstrated the suitability of a new, ready-to-use compact MRI platform using a high-field permanent magnet to assist with the evaluation of testicular toxicity. To validate the utility of the MRI platform, male mice were treated with busulfan (40 mg/kg, intraperitoneal injection). Twenty-eight days after treatment, both testes in busulfan-treated and control mice (n = 6/group) were non-invasively scanned in situ by MRI at 1 tesla. On a T1-weighted 3D gradient-echo MRI sequences (voxel size: 0.23 × 0.23 × 0.50 mm), the total testicular volume in busulfan-treated mice was significantly smaller than in controls. On T1-weighted images, the signal intensity of the testes was significantly higher in busulfan-treated mice than in controls. The mice were sacrificed, and the testes were isolated for histopathological analysis. The weight of the testes in busulfan-treated mice significantly decreased, similar to the results of the non-invasive analysis. Additionally, periodic acid-Schiff stain-positive effusions were observed in the interstitium of the busulfan-treated mouse testes, potentially explaining T1 shortening due to a high concentration of glycoproteinaceous content. The present data demonstrated a rapid evaluation of testicular toxicity in vivo by compact MRI.

Neonatal corticosterone administration increases p27-positive Sertoli cell number and decreases Sertoli cell number in the testes of mice at prepuberty.

Cortisol and corticosterone (CORT) are steroid, antistress hormones and one of the glucocorticoids in humans and animals, respectively. This study evaluated the effects of CORT administration on the male reproductive system in early life stages. CORT was subcutaneously injected at 0.36 (low-), 3.6 (middle-), and 36 (high-dosed) mg/kg body weight from postnatal day (PND) 1 to 10 in ICR mice. We observed a dose-dependent increase in serum CORT levels on PND 10, and serum testosterone levels were significantly increased only in high-dosed-CORT mice. Triiodothyronine levels were significantly higher in the low-dosed mice but lower in the middle- and high-dosed mice. However, testicular weights did not change significantly among the mice. Sertoli cell numbers were significantly reduced in low- and middle-dosed mice, whereas p27-positive Sertoli cell numbers increased in low- and middle-dosed mice. On PND 16, significant increases in testicular and relative testicular weights were observed in all-dosed-CORT mice. On PND 70, a significant decrease in testicular weight, Sertoli cell number, and spermatozoa count was observed. These results revealed that increased serum CORT levels in early life stages could induce p27 expression in Sertoli cells and terminate Sertoli cell proliferation, leading to decreased Sertoli cell number in mouse testes.

Analysis of the mylohyoid nerve in elderly Japanese cadavers for dental implant surgery.

OBJECTIVES: Injury to the mandibular nerve (MN) branches may cause pain and irregular occlusal movement during mastication after mandibular dental treatments. Growing evidence indicates that the calcitonin gene-related peptide (CGRP) plays a key role in the development of peripheral sensitization and the associated enhanced pain, suggesting it may be a sign to ensure a safe and reliable dental implant treatment. Our focus was on the distribution of the MN branches and their communication with the lingual nerve (LN), the localized expression of CGRP, and the identification of a pain area related to the mylohyoid muscle (MM) fascia in the mandibular floor. MATERIAL AND METHODS: In this study, MM samples from 440 sides of 303 human cadavers aged 61-103 years were examined microscopically and immunohistochemically. These data were further evaluated by the use of principal component analysis. RESULTS: A complex but weak attachment site was identified for the fascia of the MM. CGRP expression was mainly located in small vessels and was scattered throughout the whole fascia of the MM. Communication between the MN and LN was found in 62.5% (275/440) of the samples. The results from the principal component analysis showed that the positive contributions were from the descending branch in the premolar region (correlation coefficient value R = 0.665), the ascending branch in the molar region (R = 0.709) and the intermediate branch of the digastric branch (R = 0.720) in component 1. In the fascia off the MM, strongly labeled CGRP-positive cells were also found around the blood vessels and the nerve. CONCLUSIONS: The findings reported in this study indicate that there is a risk of damage when pulling the fascia off the MM at the border of the molar and premolar regions during dental implant surgery.

Neonatal maternal separation increases the number of p27-positive Sertoli cells in prepuberty.

Neonatal maternal separation (NMS) is an experimental model for early life stress, which affects the growth and development of various organs, resulting in adverse health effects in humans and animals. In our previous study, we demonstrated that NMS [(0.5-, 1-, 2-h/day NMS, from postnatal day (PND) 1-10] induced morphological changes to the male reproductive system, including decreased Sertoli cell numbers in mouse testes at PND 70. To clarify the mechanism by which NMS decreases Sertoli cell numbers, we evaluated the effects of NMS on mouse testes at PNDs 10 and 16. At PND 10, the Sertoli cell number was not significantly different among experimental groups; however, it decreased in 0.5- and 2-h/day NMS mice at PND 16. The termination of Sertoli cell proliferation in prepuberty can be induced by p27, a cyclin-dependent kinase inhibitor. At PND 10, we observed an increase in the number of p27-positive Sertoli cells in 2-h/day NMS mice. The seminiferous tubule diameters decreased significantly in 1- and 2-h/day NMS mice, and the relative interstitial area increased in 2-h/day NMS mice. Serum corticosterone level significantly increased, and serum testosterone level significantly decreased in the 2-h/day NMS mice. At PND 16, the tubule diameters and height of seminiferous epithelium were significantly higher in 0.5- and 2-h/day NMS mice. Our results suggest that NMS disturbs serum corticosterone and testosterone levels and increases the number of p27-positive Sertoli cells at PND 10, resulting in a decrease in the number of Sertoli cells at PND 16.

Heat shock protein A4L is a potent autoantigen for testicular autoimmunity in mice.

Experimental autoimmune orchitis (EAO) may be used as a model to investigate immunological infertility in men. Murine EAO is induced via immunization with auto-immunogenic antigens (AIAgs) from testicular germ cells (TGCs). CD4 + T cells play a crucial role in EAO induction. However, whether AIAgs induce an immune response remains unclear. We aimed to identify self-antigens that induce EAO by screening a phage display library of random TGC peptides using IgG from EAO-induced A/J mice. Twenty TGC-specific AIAgs were detected, and G protein-coupled receptor kinase 2 interacting protein-1 (GIT1) and heat shock protein A4L (HSPA4L) were identified as candidate AIAgs that induce EAO. Immunization with GIT1 or HSPA4L, emulsified in complete Freund's adjuvant, resulted in 66 % or 100 % incidence of EAO, respectively, indicating that HSPA4L is a most potent AIAg that induces EAO in mice. These findings may expectedly help improve the diagnostic procedures and treatment of immunological infertility in men.

Cytonuclear Estrogen Receptor Alpha Regulates Proliferation and Migration of Endometrial Carcinoma Cells.

OBJECTIVE: The effects of estrogen on cells are mediated by the estrogen receptor α (ERα) which localizes at the peri-membrane, cytoplasm, and the nucleus of cells. Therefore, we intended to investigate how cytonuclear ERα plays its roles in different cellular activities. METHODS: We used amino acid substituted ERα that localized at the cytoplasm and nucleus but has no direct DNA-binding activities. ERα-negative endometrial carcinoma cells (ERα-) were stably transfected with plasmid of human ERα carrying a substituted phenylalanine at position 445 with alanine (ERα-F445A). Treated with 17ß-estrogen (E2) or bazedoxifene (BDF), cell proliferation, migration, and expression of kinases related to ERα signal transduction pathways were observed. RESULTS: E2 (40 nM) significantly activated proliferation in ERα-F445A cells, but not in ERα- cells. Similarly, E2 significantly activated cell migration in ERα-F445A cells, rather than that in ERα- cells. While no obvious change in the amount of the non-phosphorylated mammalian target of Rapamycin (mTOR), the expression of mTOR phosphorylated at serine 2448 decreased, which was recovered in presence of 17ß-estrogen (E2) in the ERα-F445A cells. On the other hand, the expression of focal adhesion kinase (FAK) phosphorylated at tyrosine at 297 was attenuated in the ERα-F445A cells treated with E2. CONCLUSION: It is suggested that the cytonuclear ERα-F445A induces phosphorylation of kinases in downstream pathways, which regulate cell proliferation and migration.

Effects of phosphorylated estrogen receptor alpha on apoptosis in human endometrial epithelial cells.

It is known that the activities of estrogen receptor α (ERα) can be modulated by epidermal growth factor (EGF) through the phosphatidylinostitol 3-kinase-alpha serine/threonine protein kinase (PI3K-AKT) pathway by phosphorylation. To clarify how ERα functions are regulated in endometrial cells during menstrual cycle, molecules related to phosphorylation of ERα (pERα) were examined. It was found that the expression of phosphorylated AKT on serine 473 (pAKT-Ser473) was increased during the proliferative phase, but decreased in the secretory phase. Although the expression of pAKT on threonine 308 in the proliferative phase was only identified in the wall of arterioles, it was strongly expressed in the cytoplasm of endometrial glandular cells after entering the secretory phase. Further observations revealed that while the expression of pERα-Ser104 was constant, pERα-Ser118 was expressed following a cyclic pattern similar to that of the pAKT-Ser473. Following treatment with specific inhibitors for EGFR-PI3K-AKT pathway, it was found that while the expression of pERα-Ser118 and pERα-Ser167 was inhibited, the induced apoptosis could be antagonized by the addition of estrogen, indicating that a mitochondrial pathway is involved. Therefore, pAKT and pERα or ERα could act cooperatively on coiled arterioles and endometrial cells in order to control menstrual cycle.

An Altered DNA Methylation Status in the Human Umbilical Cord Is Correlated with Maternal Exposure to Polychlorinated Biphenyls.

Maternal exposure to polychlorinated biphenyls (PCBs) results in abnormal fetal development, possibly because of epigenetic alterations. However, the association between PCB levels in cord serum with fetal DNA methylation status in cord tissue is unclear. This study aims to identify alterations in DNA methylation in cord tissue potentially associated with PCB levels in cord serum from a birth cohort in Chiba, Japan (male neonates = 32, female neonates = 43). Methylation array analysis identified five sites for female neonates (cg09878117, cg06154002, cg06289566, cg12838902, cg01083397) and one site for male neonates (cg13368805) that demonstrated a change in the methylation degree. This result was validated by pyrosequencing analysis, showing that cg06154002 (tudor domain containing 9: TDRD9) in cord tissue from female neonates is significantly correlated with total PCB levels in cord serum. These results indicate that exposure to PCBs may alter TDRD9 methylation levels, although this hypothesis requires further validation using data obtained from female neonates. However, since the present cohort is small, further studies with larger cohorts are required to obtain more data on the effects of PCB exposure and to identify corresponding biomarkers.

Spraying urea solution reduces formaldehyde levels during gross anatomy courses.

Formaldehyde (FA) is frequently used to embalm human cadavers that are employed to teach gross anatomy to medical and dental students. However, exposure to FA is harmful to both students and educators. The aim of this study was to reduce the FA levels in the anatomy dissection hall by spraying an FA scavenger solution. We measured the changes in FA levels after administering FA scavenger solutions to liquid, wet paper towels, organs, and cadavers containing FA. Among L-cysteine, N-ethyl urea, and urea, the latter was found to have the strongest scavenging power towards the FA in the liquid. The molar concentration of urea that most efficiently reduced the levels of volatilized FA from the wet paper towels was the same as that of the FA. After spraying the urea solution, the volatilized FA levels immediately decreased, reaching their minimum at 60 min, and remained low even after 240 min. Spraying the urea solution onto the organs reduced the levels of FA volatilized from the surfaces of organs but not those from the insides of the organs. In the dissection hall used for the gross anatomy course at Tokyo Medical University, the FA levels were significantly decreased after spraying the urea solution onto the cadavers. Moreover, dissection could be performed without the cadavers putrefying during the 4-month course. These results indicate that various institutes could use urea solution spray to effectively reduce the FA levels in the dissection hall and thus ensure the safety of students and educators.