Chronic Subdural Hematoma in a Middle-Aged Amateur Scuba Diver: A Case Report.

Scuba diving has become a common and popular activity, and adverse events can occur following this activity. Among those events, intracranial hemorrhage is very rare, and only intracerebral hemorrhage and subarachnoid hemorrhage are reported. However, the occurrence of chronic subdural hematoma (CSDH), possibly as an adverse event following scuba diving, has not been described. A 49-year-old man with no significant medical history visited our hospital complaining of memory disturbance and aphasia. He had experienced a minor head trauma five months before and had gone scuba diving six times between the traumatic episode and the visit to our hospital. A brain computed tomography scan revealed a left CSDH. The patient underwent burr-hole surgery to remove the CSDH, and his symptoms resolved. We report the first case of CSDH possibly related to scuba diving. No recurrence of CSDH was observed at 28 months postoperatively.

MHC-DRB alleles with amino acids Val11, Phe13, and the shared epitopes promote collagen-induced arthritis and a rapid IgG1 response in Filipino cynomolgus macaques.

Macaques are useful animal models for studying the pathogenesis of rheumatoid arthritis (RA) and the development of anti-rheumatic drugs. The purpose of this study was to identify the major histocompatibility complex (MHC) polymorphisms associated with the pathology of collagen-induced arthritis (CIA) and anti-collagen IgG induction in a cynomolgus macaque model, as MHC polymorphisms affect the onset of CIA in other animal models. Nine female Filipino cynomolgus macaques were immunized with bovine type II collagen (b-CII) to induce CIA, which was diagnosed clinically by scoring the symptoms of joint swelling over 9 weeks. MHC polymorphisms and anti-b-CII antibody titers were compared between symptomatic and asymptomatic macaques. Four of 9 (44%) macaques were defined as the CIA-affected group. Anti-b-CII IgG in the affected group increased in titer approximately 3 weeks earlier compared with the asymptomatic group. The mean plasma IgG1 titer in the CIA-affected group was significantly higher (p < 0.05) than that of the asymptomatic group. Furthermore, the cynomolgus macaque MHC (Mafa)-DRB1*10:05 or Mafa-DRB1*10:07 alleles, which contain the well-documented RA-susceptibility five amino acid sequence known as the shared epitope (SE) in positions 70 to 74, with valine at position 11 (Val11, V11) and phenylalanine at position 13 (Phe13, F13), were detected in the affected group. In contrast, no MHC polymorphisms specific to the asymptomatic group were identified. In conclusion, the presence of V11 and F13 along with SE in the MHC-DRB1 alleles seems essential for the production of IgG1 and the rapid induction of severe CIA in female Filipino cynomolgus macaques.

Differences in daily milk production during early pregnancy alter placental characteristics and neonatal metabolic amino acid levels in dairy cows.

We investigated the effects of differences in milk production during early pregnancy on placental characteristics at full term, calf birth weights, and their metabolic status. Thirty-four Holstein cows were categorized into three groups (Low, n = 9; Middle, n = 16; High, n = 9) based on the quartile of average daily 4% fat-corrected milk production during early pregnancy. The High group showed higher milk component production than the other groups (P < 0.05) during early and mid-pregnancy. Although most placental characteristics did not differ significantly among the groups, cows in the High group had larger individual cotyledons and fewer medium-sized cotyledons than those in the Low group (P < 0.05). Plasma amino acid concentrations of calves in the Low and High groups were significantly higher than those of calves in the Middle group, although calf birth weights were similar among the groups. Furthermore, cows in the Low group had longer dry periods than those in the High (P = 0.004) and Middle (P = 0.058) groups. This suggests that cows in the Low group may have provided more amino acids to the fetus because of low lactation and long dry periods. Conversely, cows in the High group required more energy for lactation during early pregnancy, which can reduce nutrient availability to the placenta and fetus; however, increasing individual cotyledonary sizes during late pregnancy may ensure that the same amounts of amino acids as those in cows in the Low group are supplied to the fetus, recovering the birth weights.

MED26-containing Mediator may orchestrate multiple transcription processes through organization of nuclear bodies.

Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non-polyadenylated genes, including small nuclear RNAs (snRNAs) and replication-dependent histone (RDH) genes. MED26-containing Mediator plays a role in 3' Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing by supplying 3'-end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription.

Exercise intolerance and malnutrition associated with all-cause mortality in elderly patients undergoing peritoneal dialysis: a single-center prospective cohort study.

BACKGROUND: Low physical function and malnutrition in elderly patients undergoing peritoneal dialysis (PD) are important issues that may be associated with prognosis. We aimed to determine the association between physical function and nutritional status and survival in elderly patients undergoing PD. METHODS: This single-center, prospective cohort study included 45 stable, ambulatory patients undergoing PD. Physical function was measured using the 6-min walk distance (6MWD) test, 10-m walk speed, handgrip strength, lower extremity muscle strength, and short physical performance battery. Nutritional status was assessed using albumin levels and the Geriatric Nutritional Risk Index (GNRI). Patients were divided into two groups according to adverse events. Receiver operating characteristic curve analysis was used to predict mortality. The relationships between all-cause mortality and physical function and nutritional status were studied using Kaplan-Meier analysis and the log-rank test. RESULTS: The mean patient age was 75.3 ± 6.5 years. The median follow-up time was 32 (interquartile range 18-51) months, during which 11 deaths occurred. Death during follow-up was significantly associated with lower 6MWD (237.4 ± 120.2 vs. 355.2 ± 105.9 m), lower GNRI (77.3 ± 16.3 vs. 89.3 ± 8.1), and lower albumin levels (2.8 ± 0.6 vs. 3.3 ± 0.4 mg/dL) at baseline (p < 0.05). The cut-off values were 338 m, 83.3, and 2.95 g/dL for the 6MWD, GNRI, and albumin levels, respectively. The 6MWD test, GNRI, and albumin levels were significantly associated with all-cause mortality (p < 0.05). Additionally, the group with combined exercise intolerance and malnutrition had a lower survival rate (p < 0.05). CONCLUSION: Lower 6MWD and malnutrition are predictors of mortality in elderly patients undergoing PD.

Immunohistochemical identification of epithelial cell types in the isthmus of bovine oviduct: Comparison with the ampulla.

The oviductal epithelium consists of ciliated and non-ciliated cells, and their numbers vary depending on the segment of the oviduct and stage of the estrous cycle. Compared with the ampulla, fewer cyclic changes in the number of the two types of cells occur in the isthmus. Recently, we have reported that the epithelium in the ampullary oviduct is composed of many types of cells during different translational/transcriptional states, and their numbers change during the estrous cycle. However, detailed information regarding the epithelial cell subtypes lining the isthmic oviductal epithelium has not yet been reported. In this study, we aimed to identify the epithelial subtypes in the isthmus of the oviduct using immunohistochemistry. Some similarities and differences were observed between the ampulla and isthmus. As observed in the ampulla, epithelial cells of the isthmus expressed either FOXJ1 (ciliogenesis marker) or PAX8 (non-ciliated cell marker). The estrous cycle affected the number of Ki67+ cells but not that of ciliated cells. A relatively high rate of Ki67+ cells (60%) was observed at 1-4 days after the ovulation. Interestingly, unlike the ampulla, Ki67+/FOXJ1+ cells (12.6 ± 1.1%) were discovered in the isthmus. Double staining for Ki67 with FOXJ1, PAX8, or Centrin-1 (a centriole marker) revealed that Centrin-1 was localized on the apical surface of some Ki67+/FOXJ1+ cells. In conclusion, some epithelial cell subtypes exist in the isthmus of the oviduct and isthmus-specific cell subtypes have been identified. These region-specific cells may provide functional and morphological differences between the ampulla and isthmus of the oviduct.

Multiple etiologies of secondary headaches associated with arachnoid cyst, cerebrospinal fluid hypovolemia, and nontraumatic chronic subdural hematoma in an adolescent: A case report.

Background: Diagnosing the cause of headaches can be challenging. Even if intracranial lesions are found in a patient, careful assessment is essential for diagnosis, and treatment strategies will differ for each etiology. Case Description: A 16-year-old boy presented with sudden-onset headache which had lasted for 2 days. His headache was aggravated in the orthostatic position. The patient denied recent head trauma. He had been diagnosed with an arachnoid cyst (AC) in his right middle cranial fossa. Computed tomography (CT) revealed bilateral subdural effusions and slit-like lateral ventricles with no significant changes to the AC. After intravenous hydration followed by 2 days bed rest, his symptoms abated. He was diagnosed as having suffered spontaneous cerebrospinal fluid (CSF) hypovolemia. One month later, the patient experienced recurrent gradual onset headache and vomiting. CT revealed chronic right side subdural hematoma (SDH) with intracystic hemorrhage, which resulted in the elevation of intracranial pressure. An urgent hematoma evacuation was performed. He became symptom-free immediately after surgery. Postoperative follow-up CT showed no change in the AC and no recurrence of SDH. The lateral ventricles and subdural space were normal in size. Conclusion: We report a case presenting multiple types of secondary headaches, which were caused by intracranial hypotension or hypertension, with different etiologies. These were spontaneous CSF hypovolemia, nontraumatic intracystic hemorrhage form of AC, and nontraumatic chronic SDH. Although lesions seen at the time of initial diagnosis did not need surgical treatment, careful observation and repetitive imaging assessments might be useful for discovering unsuspected additional etiologies requiring surgical intervention.

Sequence Variations Within HLA-G and HLA-F Genomic Segments at the Human Leukocyte Antigen Telomeric End Associated With Acute Graft-Versus-Host Disease in Unrelated Bone Marrow Transplantation.

Acute graft-versus-host disease (aGVHD) is defined as a syndrome of an immunological response of graft to the host that occurs early after allogeneic hematopoietic stem cell transplantation (HCT). This disease is frequently observed even in HCT matched for human leukocyte antigen (HLA) alleles at multiple gene loci. Although the HLA region represents complex and diverse genomic characteristics, detailed association analysis is required for the identification of uncharacterized variants that are strongly associated with aGVHD. We genotyped three loci, OR2H2, HLA-F-AS1, and HLA-G, that are located in the 460 kb of HLA telomeric region and statistically analyzed the genotypes including HLA-DPB1 with clinical and transplantation outcomes using 338 unrelated bone marrow transplantation (UR-BMT) patient-donor pairs who were matched for HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 (HLA-10/10). Multivariate analyses demonstrated that HLA-F-AS1 and HLA-DPB1 mismatches were associated with grade II-IV aGVHD (hazard ratio (HR), 1.76; 95% CI, 1.07-2.88; p = 0.026; and HR, 1.59; CI, 1.02-2.49; p = 0.042, respectively). There was no confounding between HLA-F-AS1 and HLA-DPB1 (p = 0.512), suggesting that the HLA-F-AS1 mismatch has a strong effect on aGVHD independently of HLA-DPB1. Moreover, a stratified analysis suggested possible associations of HLA-F-AS1, HLA-DPB1, and/or HLA-G mismatches with grade II-IV aGVHD and the more severe grade III-IV aGVHD. These findings provide new insights into understanding the molecular mechanism of aGVHD caused by HLA-matched UR-BMT.

Fatal ruptured occult arteriovenous malformation in a young adult: An autopsy case report.

Background: Brain arteriovenous malformations (AVMs) are congenital developmental disorders with unclear causative factors and pathogenic mechanisms. Various epigenetic factors may influence the development and rupture of AVMs. Ruptured AVMs may lead to poor outcomes. Therefore, the risk factors of AVM rupture and treatment strategies for unruptured AVMs should be explored. Herein, we report a case of a fatal ruptured AVM diagnosed by radiological and autopsy findings and review the literature regarding AVM treatment. Case Description: A 46-year-old man was brought to the hospital with sudden loss of consciousness while sitting on the edge of the bathtub. On examination, he was unconscious with poor breathing efforts. He was intubated and a brain CT scan was performed, which showed an intracerebral hemorrhage (ICH) adjacent to the right trigone with massive intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Contrast-enhanced CT scan showed abnormal vessels adjacent to the hematoma. He was diagnosed with ICH associated with IVH and SAH caused by a ruptured abnormal vascular lesion. He underwent external ventricular drainage to control the intracranial pressure. He remained unconscious and died 16 h after hospital admission. Autopsy was performed to identify the cause of ICH. Pathological sections showed a mass of blood vessels, measuring 20 × 10 × 10 mm in size, within the hematoma with a single drainer connecting to the transverse sinus. These blood vessels had variable size, shape, and wall thickness on microscopy. Some vessels had abnormal thickened walls with discontinuous elastic fibers. Based on the radiological and autopsy findings, an ICH secondary to SpetzlerMartin Grade I AVM was confirmed. Conclusion: If the cause of ICH cannot be determined during a patient's life, autopsy may be performed to determine the pathophysiology of occult vascular lesions, including AVMs. Patients with AVMs may have moderate or no symptoms before and after rupture. Because deep AVMs fed by posterior circulation have high risk of bleeding, surgical intervention should be considered for these patients to prevent a poor outcome. Low-grade and paraventricular AVMs in a young adult may be successfully treated with multimodal surgery.

Intracranial venous reflux without the central venous occlusive disease in a patient receiving hemodialysis through brachio-brachial arteriovenous fistula: A case report.

Background: Upper-limb arteriovenous fistula as a hemodialysis access among patients with end-stage renal disease (ESRD) has become a preferred type of vascular access. However, complications involving the central nervous system may occur. There have been no reported cases of internal jugular vein (IJV) regurgitation without central venous occlusive diseases (CVODs).We describe the case of a patient on HD who presented with symptomatic IJV regurgitation without CVODs. Case Description: An 83-year-old man with ESRD receiving HD through a left upper-limb AVF presented with impaired consciousness and seizures. After recovery from unconsciousness, he became alert with cognitive impairment. The left subclavian arteriography revealed early filling of the left subclavian vein due to the AVF on the left brachium, with retrograde high-flow venous reflux to the left IJV, sigmoid and transverse sinuses, with the left central veins patent. All cerebral venous drainage procedures were dependent on the right IJV. The left internal carotid arteriography showed venous congestion of the left hemisphere. The flow of the left brachial artery was measured extremely high. Under compression of the left brachial artery to reduce the flow, the regurgitation persisted. With the findings that all cerebral venous return were in the right IJV, sacrificing the left IJV was thought to be acceptable. Left IJV ligation was performed, and the patient's cognitive function improved. Conclusion: The short-term outcome after IJV ligation may be positive in the patient who was confirmed to have a normal cerebral venous return route independent of the refluxed IJV.

Ruptured peripheral superior cerebellar artery dissecting aneurysms associated with primitive trigeminal artery: a case report.

BACKGROUND: Persistent primitive trigeminal artery (PPTA) is a remnant of the carotid-vertebrobasilar anastomoses in the embryo. Although PPTAs are discovered incidentally in most cases, altered hemodynamics may lead to increased risk of stroke. To the best of our knowledge, no reports of PPTA associated with superior cerebellar artery (SCA) dissecting aneurysms have been published in the English language. We describe the case of a patient who presented with subarachnoid hemorrhage (SAH) due to ruptured peripheral SCA dissecting aneurysms in association with PPTA. Additionally, we discuss the relationship between PPTA and peripheral SCA aneurysms and the treatment of peripheral SCA aneurysms. CASE PRESENTATION: A 43-year-old woman presented with acute onset of headache and nausea and admitted to our hospital. She was diagnosed with SAH due to ruptured left SCA dissecting aneurysm(s) and had undergone digital subtraction angiography. The left vertebral angiography showed aneurysmal dilatations of the left S2 segment (lateral pontomesencephalic segment) along with dissection through the segments of S2 and S3 (cerebellomesencephalic segment). It also showed ipsilateral PPTA. The left vertebral artery (VA) had normal caliber and the basilar artery segment proximal to the orifice of the left PPTA was not hypoplastic. The patient underwent proximal parent artery occlusion at the S2 segment via the left VA and was successfully treated with no neurological deficits having lasted 5 months. CONCLUSIONS: The flow alteration with PPTA may have influenced the formation of SCA dissection in this patient. Further studies are needed to understand the etiology and treatment outcomes of peripheral SCA aneurysms better.

A novel swab storage gel is superior to dry swab DNA collection, and enables long-range high resolution next generation sequencing HLA typing from buccal cell samples.

HLA sequence-based DNA typing (SBT) by long-range PCR amplification (LR PCR) and next-generation sequencing (NGS) is a high-throughput DNA sequencing method (LR-NGS-SBT) for the efficient and sensitive detection of novel and null HLA alleles to the field-4 level of allelic resolution without phase ambiguity. However, the accuracy and reliability of the HLA typing results using buccal cells (BCs) and saliva as genetic source materials for the LR-NGS-SBT method are dependent largely on the quality of the extracted genomic DNA (gDNA) because a large degree of gDNA fragmentation can result in insufficient PCR amplification with the incorrect assignment of HLA alleles because of allele dropouts. In this study, we developed a new cost-efficient swab storage gel (SSG) for wet swab collection of BCs (BC-SSG) and evaluated its usefulness by performing different DNA analytical parameters including LR-NGS-SBT to compare the quality and quantity of gDNA extracted from BCs (in SSG or air dried), blood and saliva of 30 subjects. The BC-SSG samples after 5 days of storage revealed qualitative and quantitative DNA values equivalent to that of blood and/or saliva and better than swabs that were only air-dried (BC-nSSG). Moreover, all the gDNA extracted from blood, saliva and BC-SSG samples were HLA-typed successfully to an equivalent total of 408 alleles for each sample type. Therefore, the application of BC-SSG collection media for LR-NGS-SBT has benefits over BC dried samples (dry swabs) such as reducing retesting and the number of untestable BC samples because of insufficient DNA amplification.

Effects of cognitive impairment and assisted peritoneal dialysis on exit-site infection in older patients.

BACKGROUND: Elderly peritoneal dialysis (PD) patients required assistance for a variety of PD-related tasks. The usefulness of assisted PD in reducing the peritonitis risk has been reported; however, there is little evidence on the effectiveness of assisted PD in preventing exit-site infections in older patients. METHODS: This was a single-center, prospective cohort study. Thirty-three patients (mean age: 74.8 ± 5.9 years) on PD were evaluated for cognitive impairment (CI) using the Japanese version of the Montreal Cognitive Assessment. They were also evaluated to determine whether they performed the exit-site care procedure alone or with assistance. Patients were categorized into four groups based on the presence or absence of CI and the presence or absence of exit-site care assistance. They were followed up until the occurrence of peritonitis and exit-site infection at the end of the follow-up. RESULTS: Altogether, 8, 8, and 17 patients were assigned to the "without CI and without assistance", "without CI and with assistance", and "with CI and with assistance groups", respectively; no patients were assigned to the "with CI and without assistance group". Six and 16 patients experienced peritonitis and exit-site infection during follow-up, respectively. Kaplan-Meier analysis and log-rank tests revealed that the "without CI and without assistance group" was significantly associated with exit-site infection (log-rank < 0.05). CONCLUSION: Patients who did not receive assistance for exit-site care were at a higher risk of exit-site infections, even in the absence of CI. Caregiver assistance is important for preventing exit-site infections in older patients on PD.

Saliva as a useful tool for evaluating upper mucosal antibody response to influenza.

Mucosal immunity plays a crucial role in controlling upper respiratory infections, including influenza. We established a quantitative ELISA to measure the amount of influenza virus-specific salivery IgA (sIgA) and salivary IgG (sIgG) antibodies using a standard antibody broadly reactive to the influenza A virus. We then analyzed saliva and serum samples from seven individuals infected with the A(H1N1)pdm09 influenza virus during the 2019-2020 flu seasons. We detected an early (6-10 days post-infection) increase of sIgA in five of the seven samples and a later (3-5 weeks) increase of sIgG in six of the seven saliva samples. Although the conventional parenteral influenza vaccine did not induce IgA production in saliva, vaccinated individuals with a history of influenza infection had higher basal levels of sIgA than those without a history. Interestingly, we observed sIgA and sIgG in an asymptomatic individual who had close contact with two influenza cases. Both early mucosal sIgA secretion and late systemically induced sIgG in the mucosal surface may protect against virus infection. Despite the small sample size, our results indicate that the saliva test system can be useful for analyzing upper mucosal immunity in influenza.

Subdural Air Increases Postoperative Recurrence of Chronic Subdural Hematoma After Initial Burr-hole Surgery Only in the Very Elderly: A Pilot Study.

OBJECTIVE: Numerous randomized controlled trials have identified risk factors increasing the postoperative recurrence of chronic subdural hematoma (CSDH). Postoperative subdural air is frequently seen on computed tomography imaging. The aim of this study was to test the hypothesis that the presence of significant subdural air postoperatively is related to recurrence of CSDH after burr-hole surgery. METHODS: A single-center, retrospective pilot study analyzed patients 20 years and older who underwent initial burr-hole surgery for CSDH. Data from 452 consecutive patients were included. Significant subdural air was considered to be present when the subdural air area was >4 cm2 in 1 axial CT slice. Correlation of the recurrence and the number of slices that included significant subdural air at postoperative day (POD) 1 was evaluated. Other classic predictive factors were also investigated. RESULTS: The recurrence rate was 13.0% in these 452 cases. After univariate analyses of all the variables, multivariate analysis for age, sex, cerebral infarction, number of slices containing significant subdural air, and maximum depth of the subdural space confirmed that older age and male sex were independent risk factors for recurrence (P = 0.032 and 0.047, respectively). After subdividing cases into older (≥75 years of age)/younger and male/female subgroups, the presence of significant subdural air at POD 1 was identified as an independent risk factor for recurrence in older adults (P = 0.025, OR = 1.12). CONCLUSIONS: Although this is a pilot study, it is suggested that significant postoperative subdural air increases recurrence after initial burr-hole surgery for CSDH in adults ≥75 years of age.

Identification of three novel HLA-DRA alleles by next-generation sequencing.

Three novel HLA-DRA alleles, DRA*01:03, DRA*01:04, and DRA*01:05 alleles with unique amino acid sequences.

Capturing Differential Allele-Level Expression and Genotypes of All Classical HLA Loci and Haplotypes by a New Capture RNA-Seq Method.

The highly polymorphic human major histocompatibility complex (MHC) also known as the human leukocyte antigen (HLA) encodes class I and II genes that are the cornerstone of the adaptive immune system. Their unique diversity (>25,000 alleles) might affect the outcome of any transplant, infection, and susceptibility to autoimmune diseases. The recent rapid development of new next-generation sequencing (NGS) methods provides the opportunity to study the influence/correlation of this high level of HLA diversity on allele expression levels in health and disease. Here, we describe the NGS capture RNA-Seq method that we developed for genotyping all 12 classical HLA loci (HLA-A, HLA-B, HLA-C, HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, HLA-DRA, HLA-DRB1, HLA-DRB3, HLA-DRB4, and HLA-DRB5) and assessing their allelic imbalance by quantifying their allele RNA levels. This is a target enrichment method where total RNA is converted to a sequencing-ready complementary DNA (cDNA) library and hybridized to a complex pool of RNA-specific HLA biotinylated oligonucleotide capture probes, prior to NGS. This method was applied to 161 peripheral blood mononuclear cells and 48 umbilical cord blood cells of healthy donors. The differential allelic expression of 10 HLA loci (except for HLA-DRA and HLA-DPA1) showed strong significant differences (P < 2.1 × 10-15). The results were corroborated by independent methods. This newly developed NGS method could be applied to a wide range of biological and medical questions including graft rejections and HLA-related diseases.

Involvement of activin signal pathway in cyclic apoptosis of the oviductal isthmic epithelium in cows.

Activin (ACV) A induces various cellular functions via activin receptor type 2 (ACVR2A/2B)-activin receptor-like kinase (ALK) 4 -Smad 2/3 pathway. Although the production of ACVA is indicated in bovine oviducts, its role on the oviduct is unclear. Oviductal isthmus needs to change its function rapidly at peri-fertilization, however, the mechanism is unknown. This study was aimed to clarify the role of ACVA in the morphological changes of oviductal isthmus in cows. First, mRNA expressions of INHBA (ACVA component) and its receptors (ALK4, ACVR2A and ACVR2B) in the isthmic tissues were examined throughout the estrous cycle. INHBA was the highest, however, ACVR2A was the lowest on the day of ovulation, suggesting reduced ACV signal transduction in the isthmus just after ovulation. Proteins of ACVRs and Smad2/3 were clearly detected in the cultured epithelial cells. It is known that ACVA regulates cellular apoptosis. Our data showed that the number of cleaved caspase-3-positive epithelial cells was largest at 2-3 days after ovulation in the isthmus. Interestingly, our study demonstrated that follistatin (ACV/TGFB/BMP inhibitor) significantly decreased the BCL2/BAX ratio in the cultured isthmic epithelial cells. To clarify which ALK pathway is involved in the regulation of BCL2/BAX ratio, the effects of SB431542 (ACV signaling (ALK4) and TGFB signaling (ALK5) inhibitor), SB525334 (ALK5 inhibitor) and LDN193189 (BMP signaling (ALK2/3) inhibitor) were investigated in the next study. The results showed that only SB431542 significantly decreased BCL2/BAX and the others had no effects. These results suggest that decreased ACVA-ACVR2A-ALK4 signal at the post-ovulation induces cyclic apoptosis of isthmic epithelial cells in bovine oviducts.

Analysis of ciliogenesis process in the bovine oviduct based on immunohistochemical classification.

The oviductal epithelium is composed of ciliated and non-ciliated cells. The proportions of these cells change during the estrous cycle. However, the mechanism underlying this cyclic change in the cell proportions remains unclear. Our previous study indicated that ciliated cells are derived from non-ciliated cells. Here, we aimed to investigate the mechanism regulating the changes in the populations of ciliated and non-ciliated cells during the estrous cycle. To this end, we examined the numbers of cells that were positive for acetylated-α-tubulin (cilia marker), Ki67 (proliferation marker), PAX8 (non-ciliated cell marker), and FOXJ1 and MYB (ciliogenesis markers) in the epithelial cells at four different estrous stages (Stage I: days 1-4 after ovulation, Stage II: days 5-10, Stage III: days 11-17, and Stage IV: days 18-20) by immunohistochemistry. The oviductal epithelial cells expressed either FOXJ1 or PAX8. All the acetylated-α-tubulin+ cells were positive for FOXJ1, although there were a few acetylated-α-tubulin-/FOXJ1+ cells. MYB was expressed in both the FOXJ1+ and PAX8+ cells, but it was not expressed in the Ki67+ cells. The numbers of Ki67+ and MYB+ cells were the highest in Stage IV, while the numbers of FOXJ1+ and acetylated-α-tubulin+ cells were the highest in the following Stage I, suggesting that ciliogenesis is associated with the estrous cycle. Thus, based on immunological classification, the oviductal epithelium contains at least seven types of cells at different translational/transcriptional states, and their number is regulated by the estrous cycle. This cyclic event might provide an optimal environment for gamete transport, fertilization, and embryonic development.