Drug-induced sarcoidosis-like reaction three months after BNT162b2 mRNA COVID-19 vaccination: A case report and review of literature.

BACKGROUND: A 70-year-old man with hepatitis C virus-related recurrent hepatocellular carcinoma was admitted for further diagnosis of a 1 cm iso-hyperechoic nodule in segment (S) 5. CASE SUMMARY: Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) revealed the nodule in S5 with a defect at the hepatobiliary phase, hyperintensity on diffusion weighted imaging (DWI) and hypointensity on apparent diffusion coefficient (ADC) map. Contrast-enhanced computed tomography revealed hypervascularity at the early phase, and delayed contrast-enhancement was observed at the late phase. Contrast-enhanced ultrasound (US) revealed incomplete defect at the late vascular phase. Inflammatory liver tumor, lymphoproliferative disease, intrahepatic cholangiocarcinoma (small duct type) and bile duct adenoma were suspected through the imaging studies. US guided biopsy, however, showed a noncaseating hepatic sarcoid-like epithelioid granuloma (HSEG), and histopathological analysis disclosed spindle shaped epithelioid cells harboring Langhans-type multinucleated giant cells. One month after admission, EOB-MRI signaled the disappearance of the defect at the hepatobiliary phase, of hyperintensity on DWI, of hypointensity on ADC map, and no stain at the early phase. CONCLUSION: That the patient had received BNT162b2 messenger RNA (mRNA) coronavirus disease 2019 vaccination 3 mo before the occurrence of HSEG, and that its disappearance was confirmed 4 mo after mRNA vaccination suggested that the drug-induced sarcoidosis-like reaction (DISR) might be induced by the mRNA vaccination. Fortunately, rechallenge of drug-induced DISR with the third mRNA vaccination was not confirmed.

ADAD2 functions in spermiogenesis and piRNA biogenesis in mice.

BACKGROUND: Adenosine deaminase domain containing 2 (ADAD2) is a testis-specific protein composed of a double-stranded RNA binding domain and a non-catalytic adenosine deaminase domain. A recent study showed that ADAD2 is indispensable for the male reproduction in mice. However, the detailed functions of ADAD2 remain elusive. OBJECTIVES: This study aimed to investigate the cause of male sterility in Adad2 mutant mice and to understand the molecular functions of ADAD2. MATERIALS AND METHODS: Adad2 homozygous mutant mouse lines, Adad2-/- and Adad2Δ/Δ , were generated by CRISPR/Cas9. Western blotting and immunohistochemistry were used to reveal the expression and subcellular localization of ADAD2. Co-immunoprecipitation tandem mass spectrometry was employed to determine the ADAD2-interacting proteins in mouse testes. RNA-sequencing analyses were carried out to analyze the transcriptome and PIWI-interacting RNA (piRNA) populations in wildtype and Adad2 mutant testes. RESULTS: Adad2-/- and Adad2Δ/Δ mice exhibit male-specific sterility because of abnormal spermiogenesis. ADAD2 interacts with multiple RNA-binding proteins involved in piRNA biogenesis, including MILI, MIWI, RNF17, and YTHDC2. ADAD2 co-localizes and forms novel granules with RNF17 in spermatocytes. Ablation of ADAD2 impairs the formation of RNF17 granules, decreases the number of cluster-derived pachytene piRNAs, and increases expression of ping-pong-derived piRNAs. DISCUSSION AND CONCLUSION: In collaboration with RNF17 and other RNA-binding proteins in spermatocytes, ADAD2 directly or indirectly functions in piRNA biogenesis.

Upregulated Ribosomal Pathway Impairs Follicle Development in a Polycystic Ovary Syndrome Mouse Model: Differential Gene Expression Analysis of Oocytes.

Polycystic ovary syndrome (PCOS), a common endocrine disorder, is associated with impaired oocyte development, leading to infertility. However, the pathogenesis of PCOS has not been completely elucidated. This study aimed to determine the differentially expressed genes (DEGs) and epigenetic changes in the oocytes from a PCOS mouse model to identify the etiological factors. RNA-sequencing analysis revealed that 90 DEGs were upregulated and 27 DEGs were downregulated in mice with PCOS compared with control mice. DNA methylation analysis revealed 30 hypomethylated and 10 hypermethylated regions in the PCOS group. However, the DNA methylation status did not correlate with differential gene expression. The pathway enrichment analysis revealed that five DEGs (Rps21, Rpl36, Rpl36a, Rpl37a, and Rpl22l1) were enriched in ribosome-related pathways in the oocytes of mice with PCOS, and the immunohistochemical analysis revealed significantly upregulated expression levels of Rps21 and Rpl36. These results suggest that differential gene expression in the oocytes of mice in PCOS is related to impaired folliculogenesis. These findings improve our understanding of PCOS pathogenesis.

Cervical Edema Extending to the Larynx as Local Cytokine Release Syndrome Following Chimeric Antigen Receptor T-Cell Therapy in a Boy with Refractory Acute Lymphoblastic Leukemia.

Cytokine release syndrome (CRS) is one of the major acute complications caused by massive cytokine release after chimeric antigen receptor (CAR) T-cell therapy. Patients with tumor masses were considered at high risk of local CRS induced by the expansion of CAR T cells in the tumor masses. However, even patients without any tumor burden around the neck are at risk of developing cervical edema as local CRS, which can lead to life-threatening airway obstruction. Here, we present the case of a 15-year-old boy who developed cervical edema as a local CRS after CAR T-cell therapy for refractory acute lymphoblastic leukemia. Despite administration of tocilizumab and methylprednisolone for persistent fever as a symptom of systemic CRS after CAR T-cell therapy, cervical edema occurred and extended to the larynx, resulting in dysphagia and hoarseness. Dexamethasone was remarkably effective, and the laryngeal symptoms resolved within a few hours. Local cytokine syndrome showed exacerbation with tocilizumab but exhibited considerable improvement with dexamethasone administration.

Phosphodiesterase 5 inhibitor suppresses prostate weight increase in type 2 diabetic rats.

AIMS: Hyperinsulinemia is an important causative factor of prostate enlargement in type 2 diabetes (T2D), however, clinically prostate weight increases during hypoinsulinemic condition. To investigate the pathogenesis of prostate enlargement and effects of phosphodiesterase 5 inhibitor (PDE5i), male Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats were used as T2D and control, respectively. MATERIALS AND METHODS: OLETF and LETO rats were treated with oral tadalafil (100 µg/kg/day) or vehicle for 12 wks from at the age of 36 wks. KEY FINDINGS: Prostate weight of OLETF rats was significantly higher than that of LETO at 36 wks, and increased at 48 wks. In OLETF rats, prostate blood flow was significantly lower at 48 wks versus 36 wks. Twelve-week-tadalafil treatment increased prostate blood flow and suppressed prostate weight increase in both strains. This change was inversely correlated with changes in prostate expressions of hypoxia-inducible factor-1 alpha (HIF-1α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Increases with age were observed in mRNA and/or protein levels of cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-α) and cell growth factors insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor (bFGF), and transforming growth factor-beta (TGF-ß); especially IL-6, TNF-α, IGF-1, bFGF and TGF-ß increased with T2D. Tadalafil suppressed these cytokines and growth factors. SIGNIFICANCE: These data suggest chronic ischemia caused by T2D leads to oxidative stress, resulting in prostate enlargement through upregulation of several cytokines and growth factors. Treatment with PDE5i improves prostate ischemia and might prevent enlargement via suppression of cytokines and growth factors in T2D.

Ultrasound-guided lung biopsy with coaxial technique: pleural contact length affects the occurrence of pneumothorax after first puncture.

PURPOSE: To assess prebiopsy characteristics influencing the occurrence of pneumothorax after first puncture of ultrasound (US)-guided lung biopsy with coaxial technique. MATERIALS AND METHODS: From January 2007 to September 2018, 180 peripheral lung lesions in 174 patients who underwent B-mode US-guided lung biopsy with coaxial technique at single institution were included in this study. Technical success was defined as the ability to make a diagnosis using the acquired sample with/without an adverse event of pneumothorax. Statistical analyses of prebiopsy characteristics were performed to identify the most important cutpoint and to evaluate the effect on diagnostic accuracy. RESULTS: Of the 180 lesions (mean size, 37 mm ± 26.2; mean pleural contact length, 38.2 mm ± 34.4), technical success rate was 97.2% (175/180 lesions) and diagnostic accuracy rate was 91.6% (165/180 lesions). Pneumothorax occurred immediately after first puncture for seven of 180 lesions. Classification and regression tree analysis and Fisher's exact test showed the proportion of the pneumothorax immediately after first puncture was higher in lesions with pleural contact length less than 9.78 mm (p = 0.002). No significant difference was shown between the pneumothorax and non-pneumothorax after first puncture in technical success and final diagnosis success rate. CONCLUSION: Pleural contact length affects the occurrence of pneumothorax after first puncture of US-guided lung biopsy with coaxial technique.

Deciphering two rounds of cell lineage segregations during bovine preimplantation development.

Blastocyst formation gives rise to the inner cell mass (ICM) and trophectoderm (TE) and is followed by the differentiation of the epiblast (Epi) and primitive endoderm (PrE) within the ICM. Although these two-round cell lineage differentiations underpin proper embryogenesis in every mammal, their spatiotemporal dynamics are quite diverse among species. Here, molecular details of the blastocyst stage in cattle were dissected using an optimized in vitro culture method. Blastocyst embryos were placed on agarose gel filled with nutrient-rich media to expose embryos to both gaseous and liquid phases. Embryos derived from this "on-gel" culture were transferred to surrogate mothers on day (D) 10 after fertilization and successfully implanted. Immunofluorescent studies using on-gel-cultured embryos revealed that the proportion of TE cells expressing the pluripotent ICM marker, OCT4, which was beyond 80% on D8, was rapidly reduced after D9 and reached 0% on D9.5. This first lineage segregation process was temporally parallel with the second one, identified by the spatial separation of Epi cells expressing SOX2 and PrE cells expressing SOX17. RNA-seq comparison of TE cells from D8 in vitro fertilized embryos and D14 in vivo embryos revealed that besides drastic reduction of pluripotency-related genes, TE cells highly expressed Wnt, FGF, and VEGF signaling pathways-related genes to facilitate the functional maturation required for feto-maternal interaction. Quantitative PCR analysis of TE cells derived from on-gel culture further confirmed time-dependent increments in the expression of key TE markers. Altogether, the present study provides platforms to understand species-specific strategies for mammalian preimplantation development.

Dorso-ventral heterogeneity in tracheal basal stem cells.

The tracheal basal cells (BCs) function as stem cells to maintain the epithelium in steady state and repair it after injury. The airway is surrounded by cartilage ventrolaterally and smooth muscle dorsally. Lineage tracing using Krt5-CreER shows dorsal BCs produce more, larger, clones than ventral BCs. Large clones were found between cartilage and smooth muscle where subpopulation of dorsal BCs exists. Three-dimensional organoid culture of BCs demonstrated that dorsal BCs show higher colony forming efficacy to ventral BCs. Gene ontology analysis revealed that genes expressed in dorsal BCs are enriched in wound healing while ventral BCs are enriched in response to external stimulus and immune response. Significantly, ventral BCs express Myostatin, which inhibits the growth of smooth muscle cells, and HGF, which facilitates cartilage repair. The results support the hypothesis that BCs from the dorso-ventral airways have intrinsic molecular and behavioural differences relevant to their in vivo function.

Distant metastasis of hepatocellular carcinoma to Meckel's cave and cranial nerves: A case report and review of literature.

BACKGROUND: Metastasis occurs as a late event in the natural history of hepatocellular carcinoma (HCC), and most patients die of liver failure attributed to the tumor supplanting the liver. Conversely, the brain is a less common metastatic site. CASE SUMMARY: We describe a rare case of hepatitis C virus-related multiple HCC metastasizing to the cavernous sinus, Meckel's cave, and the petrous bone involving multiple cranial nerves in an 82-year-old woman. At admission imaging studies including Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (MRI) revealed multiple HCC nodules in both right and left lobes. Ultrasound guided biopsy of the left lobe revealed moderately differentiated HCC. Molecular targeted therapy with Lenvatinib (8 mg/d for 94 d, per os) and Ramucirumab (340 mg/d and 320 mg/d, two times by intravenous injection) were administered for 4 mo, resulting in progression of the disease. Three months after the start of molecular target therapy, the patient presented with symptoms of hyperalgesia of the right face and limited abduction of the right eye, indicating disturbances in the right trigeminal and abducens nerves. Brain MRI disclosed a mass involving the cavernous sinus, Meckel's cave and the petrous bone. Contrast-enhanced MRI with gadolinium-chelated contrast medium revealed a well-defined mass with abnormal enhancement around the right cavernous sinus and the right Meckel's cave. CONCLUSION: The diagnosis of metastatic HCC to the cavernous sinus, Meckel's cave, and the petrous bone was made based on neurological findings and imaging studies including MRI, but not on histological examinations. Further studies may provide insights into various methods for diagnosing HCC metastasizing to the craniospinal area.

Impact of self-decision to stop cancer treatment on advanced genitourinary cancer patients.

ABSTRACT: Decision-making to stop cancer treatment in patients with advanced cancer is stressful, and it significantly influences subsequent end-of-life palliative treatment. However, little is known about the extent to which the patient's self-decisions influenced the prognostic period. This study focused on the patient's self-decision and investigated the impact of the self-decision to stop cancer treatment on their post-cancer treatment survival period and place of death.We retrospectively analyzed 167 cases of advanced genitourinary cancer patients (kidney cancer: 42; bladder cancer: 68; prostate cancer: 57) treated at the University of Fukui Hospital (UFH), who later died because of cancer. Of these, 100 patients decided to stop cancer treatment by themselves (self-decision group), while the families of the remaining 67 patients (family's decision group) decided to stop treatment on their behalf because the patient's decision-making ability was already impaired. Differences in the post-cancer-treatment survival period and place of death between the 2 groups were examined. The association between place of death and survival period was also analyzed.The median survival period after terminating cancer treatment was approximately 6 times longer in the self-decision group (145.5 days in self-decision group vs 23.0 days in family's decision group, P < .001). Proportions for places of death were as follows: among the self-decision group, 42.0% of patients died at UFH, 45.0% at other medical institutions, and 13.0% at home; among the family's decision group, 62.7% died at UFH, 32.8% at other medical institutions, and 4.5% at home. The proportion of patients who died at UFH was significantly higher among the family's decision group (P = .011). The median survival period was significantly shorter for patients who died at UFH (UFH: 30.0 days; other institutions/home: 161.0 days; P < .001).Significantly longer post-cancer-treatment survival period and higher home death rate were observed among patients whose cancer treatment was terminated based on their self-decision. Our results provide clinical evidence, especially in terms of prognostic period and place of death that support the importance of discussing bad news, such as stopping cancer treatment with patients.

Urinary reabsorption in the rat kidney by anticholinergics.

Anticholinergics, therapeutic agents for overactive bladder, are clinically suggested to reduce urine output. We investigated whether this effect is due to bladder or kidney urine reabsorption. Various solutions were injected into the bladder of urethane-anesthetized SD rats. The absorption rate for 2 h was examined following the intravenous administration of the anticholinergics imidafenacin (IM), atropine (AT), and tolterodine (TO). The bilateral ureter was then canulated and saline was administered to obtain a diuretic state. Anticholinergics or 1-deamino-[8-D-arginine]-vasopressin (dDAVP) were intravenously administered. After the IM and dDAVP administrations, the rat kidneys were immunostained with AQP2 antibody, and intracellular cAMP was measured. The absorption rate was ~ 10% of the saline injected into the bladder and constant even when anticholinergics were administered. The renal urine among peaked 2 h after the saline administration. Each of the anticholinergics significantly suppressed the urine production in a dose-dependent manner, as did dDAVP. IM and dDAVP increased the intracellular cAMP levels and caused the AQP2 molecule to localize to the collecting duct cells' luminal side. The urinary reabsorption mechanism through the bladder epithelium was not activated by anticholinergic administration. Thus, anticholinergics suppress urine production via an increase in urine reabsorption in the kidneys' collecting duct cells via AQP2.

Proposal of selective wedge instillation of pulmonary surfactant for COVID-19 pneumonia based on computational fluid dynamics simulation.

BACKGROUND: The most important target cell of SARS-CoV-2 is Type II pneumocyte which produces and secretes pulmonary surfactant (PS) that prevents alveolar collapse. PS instillation therapy is dramatically effective for infant respiratory distress syndrome but has been clinically ineffective for ARDS. Nowadays, ARDS is regarded as non-cardiogenic pulmonary edema with vascular hyper-permeability regardless of direct relation to PS dysfunction. However, there is a possibility that this ineffectiveness of PS instillation for ARDS is caused by insufficient delivery. Then, we performed PS instillation simulation with realistic human airway models by the use of computational fluid dynamics, and investigated how instilled PS would move in the liquid layer covering the airway wall and reach to alveolar regions. METHODS: Two types of 3D human airway models were prepared: one was from the trachea to the lobular bronchi and the other was from a subsegmental bronchus to respiratory bronchioles. The thickness of the liquid layer covering the airway was assigned as 14 % of the inner radius of the airway segment. The liquid layer was assumed to be replaced by an instilled PS. The flow rate of the instilled PS was assigned a constant value, which was determined by the total amount and instillation time in clinical use. The PS concentration of the liquid layer during instillation was computed by solving the advective-diffusion equation. RESULTS: The driving pressure from the trachea to respiratory bronchioles was calculated at 317 cmH2O, which is about 20 times of a standard value in conventional PS instillation method where the driving pressure was given by difference between inspiratory and end-expiratory pressures of a ventilator. It means that almost all PS does not reach the alveolar regions but moves to and fro within the airway according to the change in ventilator pressure. The driving pressure from subsegmental bronchus was calculated at 273 cm H2O, that is clinically possible by wedge instillation under bronchoscopic observation. CONCLUSIONS: The simulation study has revealed that selective wedge instillation under bronchoscopic observation should be tried for COVID-19 pneumonia before the onset of ARDS. It will be also useful for preventing secondary lung fibrosis.

Severe Liver Disorder Following Liver Transplantation in STING-Associated Vasculopathy with Onset in Infancy.

PURPOSE: STING-associated vasculopathy with onset in infancy (SAVI) is a type-I interferonopathy, characterized by systemic inflammation, peripheral vascular inflammation, and pulmonary manifestations. There are three reports of SAVI patients developing liver disease, but no report of a SAVI patient requiring liver transplantation. Therefore, the relevance of liver inflammation is unclear in SAVI. We report a SAVI patient who developed severe liver disorder following liver transplantation. METHODS: SAVI was diagnosed in a 4-year-old girl based on genetic analysis by whole-exome sequencing. We demonstrated clinical features, laboratory findings, and pathological examination of her original and transplanted livers. RESULTS: At 2 months of age, she developed bronchitis showing resistance to bronchodilators and antibiotics. At 10 months of age, she developed liver dysfunction with atypical cholangitis, which required liver transplantation at 1 year of age. At 2 years of age, multiple biliary cysts developed in the transplanted liver. At 3.9 years of age, SAVI was diagnosed by whole-exome sequencing. Inflammatory cells from the liver invaded the stomach wall directly, leading to fatal gastrointestinal bleeding unexpectedly at 4.6 years of age. In pathological findings, there were no typical findings of liver abscess, vasculitis, or graft rejection, but biliary cysts and infiltration of inflammatory cells, including plasmacytes around the bile duct area, in the transplanted liver were noted, which were findings similar to those of her original liver. CONCLUSION: Although further studies to clarify the mechanisms of the various liver disorders described in SAVI patients are needed, inflammatory liver manifestations may be amplified in the context of SAVI.

Food-Derived Compounds Apigenin and Luteolin Modulate mRNA Splicing of Introns with Weak Splice Sites.

Cancer cells often exhibit extreme sensitivity to splicing inhibitors. We identified food-derived flavonoids, apigenin and luteolin, as compounds that modulate mRNA splicing at the genome-wide level, followed by proliferation inhibition. They bind to mRNA splicing-related proteins to induce a widespread change of splicing patterns in treated cells. Their inhibitory activity on splicing is relatively moderate, and introns with weak splice sites tend to be sensitive to them. Such introns remain unspliced, and the resulting intron-containing mRNAs are retained in the nucleus, resulting in the nuclear accumulation of poly(A)+ RNAs in these flavonoid-treated cells. Tumorigenic cells are more susceptible to these flavonoids than nontumorigenic cells, both for the nuclear poly(A)+ RNA-accumulating phenotype and cell viability. This study illustrates the possible mechanism of these flavonoids to suppress tumor progression in vivo that were demonstrated by previous studies and provides the potential of daily intake of moderate splicing inhibitors to prevent cancer development.

Evolution of imprinting via lineage-specific insertion of retroviral promoters.

Imprinted genes are expressed from a single parental allele, with the other allele often silenced by DNA methylation (DNAme) established in the germline. While species-specific imprinted orthologues have been documented, the molecular mechanisms underlying the evolutionary switch from biallelic to imprinted expression are unknown. During mouse oogenesis, gametic differentially methylated regions (gDMRs) acquire DNAme in a transcription-guided manner. Here we show that oocyte transcription initiating in lineage-specific endogenous retroviruses (ERVs) is likely responsible for DNAme establishment at 4/6 mouse-specific and 17/110 human-specific imprinted gDMRs. The latter are divided into Catarrhini- or Hominoidea-specific gDMRs embedded within transcripts initiating in ERVs specific to these primate lineages. Strikingly, imprinting of the maternally methylated genes Impact and Slc38a4 was lost in the offspring of female mice harboring deletions of the relevant murine-specific ERVs upstream of these genes. Our work reveals an evolutionary mechanism whereby maternally silenced genes arise from biallelically expressed progenitors.

Primary jejunal Burkitt lymphoma in a child: ultrasonic detection.

Gastrointestinal Burkitt lymphoma (BL) is a highly aggressive malignancy in childhood, and early treatment is critical for its favorable prognosis. Ultrasonography is a widely accepted initial imaging workup; therefore, recognition of the sonographic features of BL should contribute to its early diagnosis and initiation of treatment. We present a 4-year-old boy with primary jejunal BL with intussusception mimicking presentation, in which initial abdominal US allowed sustainable detection and characterization of the intestinal lesion. Jejunotomy was performed and histopathological analysis revealed a 'starry sky' pattern and c-myc split signals characteristic of BL. The patient remains disease-free following chemotherapy.

Genome-wide methylation profiles in primary intracranial germ cell tumors indicate a primordial germ cell origin for germinomas.

Intracranial germ cell tumors (iGCTs) are the second most common brain tumors among children under 14 in Japan. The World Health Organization classification recognizes several subtypes of iGCTs, which are conventionally subclassified into pure germinoma or non-germinomatous GCTs. Recent exhaustive genomic studies showed that mutations of the genes involved in the MAPK and/or PI3K pathways are common in iGCTs; however, the mechanisms of how different subtypes develop, often as a mixed-GCT, are unknown. To elucidate the pathogenesis of iGCTs, we investigated 61 GCTs of various subtypes by genome-wide DNA methylation profiling. We showed that pure germinomas are characterized by global low DNA methylation, a unique epigenetic feature making them distinct from all other iGCTs subtypes. The patterns of methylation strongly resemble that of primordial germ cells (PGC) at the migration phase, possibly indicating the cell of origin for these tumors. Unlike PGC, however, hypomethylation extends to long interspersed nuclear element retrotransposons. Histologically and epigenetically distinct microdissected components of mixed-GCTs shared identical somatic mutations in the MAPK or PI3K pathways, indicating that they developed from a common ancestral cell.

Imaging of metastases from breast cancer to uncommon sites: a pictorial review.

There are three types of breast cancer recurrence which can occur after initial treatment: local, regional, and distant. Distant metastases are more frequent than local and regional recurrences. It usually occurs several years after the primary breast cancer, although it is sometimes diagnosed at the same time as the primary breast cancer. Although the common distant metastases are bone, lung and liver, breast cancer has the potential to metastasize to almost any region of the body. Early detection and treatment of distant metastases improves the prognosis, therefore radiologists and clinicians should recognize the possibility of metastasis from breast cancer and grasp the imaging characteristics. In this report, we demonstrate the imaging characteristics of metastases from breast cancer to uncommon sites.

DNA methylation and gene expression dynamics during spermatogonial stem cell differentiation in the early postnatal mouse testis.

BACKGROUND: In the male germline, neonatal prospermatogonia give rise to spermatogonia, which include stem cell population (undifferentiated spermatogonia) that supports continuous spermatogenesis in adults. Although the levels of DNA methyltransferases change dynamically in the neonatal and early postnatal male germ cells, detailed genome-wide DNA methylation profiles of these cells during the stem cell formation and differentiation have not been reported. RESULTS: To understand the regulation of spermatogonial stem cell formation and differentiation, we examined the DNA methylation and gene expression dynamics of male mouse germ cells at the critical stages: neonatal prospermatogonia, and early postntal (day 7) undifferentiated and differentiating spermatogonia. We found large partially methylated domains similar to those found in cancer cells and placenta in all these germ cells, and high levels of non-CG methylation and 5-hydroxymethylcytosines in neonatal prospermatogonia. Although the global CG methylation levels were stable in early postnatal male germ cells, and despite the reported scarcity of differential methylation in the adult spermatogonial stem cells, we identified many regions showing stage-specific differential methylation in and around genes important for stem cell function and spermatogenesis. These regions contained binding sites for specific transcription factors including the SOX family members. CONCLUSIONS: Our findings show a distinctive and dynamic regulation of DNA methylation during spermatogonial stem cell formation and differentiation in the neonatal and early postnatal testes. Furthermore, we revealed a unique accumulation and distribution of non-CG methylation and 5hmC marks in neonatal prospermatogonia. These findings contrast with the reported scarcity of differential methylation in adult spermatogonial stem cell differentiation and represent a unique phase of male germ cell development.

[A case of metachronal testicular tumor eight years after medical treatment of extragonadal germ cell tumor].

A 22-year-old man was admitted to our hospital complaining of a left cervical mass. Computed tomography (CT) showed multiple enlarged lymph nodes at the left cervical vein and para-aortic areas. Histological examination of a biopsy indicated an embryonal carcinoma. The levels of human ß-chorionic gonadotropin (ß-HCG) and lactic dehydrogenase (LDH) were both elevated. Ultrasonography revealed testicular calcification, but there were no findings on magnetic resonance imaging (MRI). The patient was diagnosed as having an extragonadal germ cell tumor. After four courses of chemotherapy with BEP protocol (bleomycin, etoposide and cisplatin), retroperineal lymph node dissection (RPLND) was performed and there was no involvement of the viable cells in the resected lymph nodes. Eight years after chemotherapy, he noticed an enlargement of his left scrotum without pain. ß-HCG was again elevated. A unilateral high orchiectomy was performed, and histology revealed a seminoma. He was staged as pT1N0M0S0. Six months later he remains disease-free.