Effects of hypernatremia on the microglia.

Signs and symptoms of hypernatremia largely indicate central nervous system dysfunction. Acute hypernatremia can cause demyelinating lesions similar to that observed in osmotic demyelination syndrome (ODS). We have previously demonstrated that microglia accumulate in ODS lesions and minocycline protects against ODS by inhibiting microglial activation. However, the direct effect of rapid rise in the sodium concentrations on microglia is largely unknown. In addition, the effect of chronic hypernatremia on microglia also remains elusive. Here, we investigated the effects of acute (6 or 24 h) and chronic (the extracellular sodium concentration was increased gradually for at least 7 days) high sodium concentrations on microglia using the microglial cell line, BV-2. We found that both acute and chronic high sodium concentrations increase NOS2 expression and nitric oxide (NO) production. We also demonstrated that the expression of nuclear factor of activated T-cells-5 (NFAT5) is increased by high sodium concentrations. Furthermore, NFAT5 knockdown suppressed NOS2 expression and NO production. We also demonstrated that high sodium concentrations decreased intracellular Ca2+ concentration and an inhibitor of Na+/Ca2+ exchanger, NCX, suppressed a decrease in intracellular Ca2+ concentrations and NOS2 expression and NO production induced by high sodium concentrations. Furthermore, minocycline inhibited NOS2 expression and NO production induced by high sodium concentrations. These in vitro data suggest that microglial activity in response to high sodium concentrations is regulated by NFAT5 and Ca2+ efflux through NCX and is suppressed by minocycline.

A Pregnant Woman with Excess Vasopressinase-Induced Diabetes Insipidus Complicated by Central Diabetes Insipidus like Lymphocytic Infundibulo-Neurohypophysitis.

Background: Gestational diabetes insipidus (DI) is a very rare complication of pregnancy. We present a case of gestational DI combining two different types of DI. Case Presentation. A 39-year-old pregnant woman suddenly presented with thirst, polydipsia, and polyuria after 31 gestation weeks (GWs). Based on laboratory findings of hypotonic urine (78 mOsm/kgH2O) with higher plasma osmolality (298 mOsm/kgH2O) and higher serum sodium levels (149 mEq/L), gestational DI was suspected, and the clinical course was monitored without therapy until the results of a measurement of plasma arginine vasopressin (AVP) levels were available. However, she subsequently developed acute prerenal failure and underwent an emergency cesarean section at 34 GWs. Her resected placenta weighed 920 g, nearly twice the normal weight. Immediately following delivery, intranasal 1-desamino-8-D-arginine vasopressin was administered, and her symptoms promptly disappeared. Afterward, her predelivery plasma AVP level was found to have been inappropriately low (0.7 pg/mL) given her serum sodium level. The patient's serum vasopressinase level just before delivery was 2,855 ng/mL, more than 1,000 times the upper limit of the normal range, suggesting excess vasopressinase-induced DI. The presence of anti-rabphilin-3A antibodies in the patient's blood, a hypertonic saline infusion test result, and loss of the high-intensity signal of the posterior pituitary on fat-suppressed T1-weighted magnetic resonance images without thickening of the stalk and enlargement of the neurohypophysis suggested concurrent central DI-like lymphocytic infundibulo-neurohypophysitis (LINH). Conclusion: In addition to the degradation of AVP by excess placental vasopressinase due to the enlarged placenta, an insufficient compensatory increase in AVP secretion from the posterior pituitary gland due to LINH-like pathogenesis might have led to DI symptoms.

Development of adolescent childhood cancer survivors' psychosocial issues scale.

BACKGROUND: Follow-up care for adolescent childhood cancer survivors (ACCS) after they return to school requires an understanding of their psychosocial issues. Therefore, this study developed the adolescent childhood cancer survivors' psychosocial issues scale (ACCSPIS) and evaluated its reliability and validity. METHODS: In the development phase, pediatric oncology clinical professionals created the 24 item questionnaire of ACCS's psychosocial issues. In the feasibility phase, a survey was administered to 165 ACCS aged 12-18 years after discharge from hospital in Japan, and 57 completed questionnaires were analyzed. The survey items were psychosocial issues, attributes, K6 scale, and impact of event scale-revised (IES-R) scale. Factor analysis was conducted for psychosocial issues. Regarding reliability, Cronbach's α coefficients and item-total correlation coefficients were calculated. Regarding validity, Spearman's rank correlation coefficients between ACCSPIS and K6 and IES-R were calculated, and confirmatory factor analysis was conducted. RESULTS: Four factors comprising 15 items were extracted: "appearance changes due to treatment effects," "anxiety about marriage and the future," "change in appearance due to treatment", and "psychological distress due to interpersonal relationships and information about the disease." The model fit was good, with a total ACCSPIS α coefficient of 0.901 and α coefficients for the subscales ranging from 0.651 to 0.914. The K6 and IES-R were significantly associated with the total ACCSPIS, and item-total correlations were satisfactory. CONCLUSIONS: The reliability and validity of ACCSPIS were generally confirmed. This scale could be useful to measure psychosocial issues in ACCS aged 12-18 years after their return to school.

Lymphocytic Infundibuloneurohypophysitis Diagnosis Owing to Positive Anti-rabphilin-3A Antibody Test Result in an 8-year-old Boy with Early-onset Central Diabetes Insipidus.

Childhood-onset lymphocytic infundibuloneurohypophysitis (LINH) has rarely been reported. Pathological evaluation via pituitary biopsy is necessary for a definitive diagnosis of LINH. However, pituitary biopsy is a highly invasive procedure. Recently, anti-rabphilin-3A antibody (RPH3A-Ab) has been reported as a promising diagnostic marker for LINH in adults; however, there are few such reports in the pediatric population. We report the case of an 8-year-old boy with central diabetes insipidus (CDI) who was clinically diagnosed with LINH based on RPH3A-Ab positivity. He was diagnosed with CDI using a water deprivation test combined with desmopressin administration. Serum and cerebrospinal fluid tumor markers were negative, and T1-weighted magnetic resonance imaging (MRI) revealed the absence of high signal intensity in the posterior pituitary gland and an enlarged pituitary stalk. Anterior pituitary function tests revealed no abnormalities. No pituitary biopsy was performed because of its invasive nature, and desmopressin treatment was initiated. Three months after CDI onset, the patient tested positive for RPH3A-Ab. MRI performed 9 months after CDI onset revealed amelioration of the pituitary stalk enlargement, and the clinical course corroborated our diagnosis of LINH. RPH3A-Ab may be useful as an early diagnostic tool for LINH in the pediatric population.

Two children with lymphocytic hypophysitis presenting with positive anti-rabphilin-3A antibody.

Lymphocytic hypophysitis (LYH) is a rare chronic inflammatory disease characterized by lymphocytic infiltration of the anterior or posterior pituitary gland and hypothalamus. LYH is subdivided into lymphocytic adenohypophysitis (LAH), lymphocytic infundibulo-neurohypophysitis (LINH), and lymphocytic panhypophysitis (LPH) depending on the primary site. Most cases occur in adults, with few cases reported in children, and it is especially important to distinguish LYH from suprasellar malignancies, such as germ cell tumors and other neoplastic diseases. Although a biopsy is necessary for definitive diagnosis, it is desirable to be able to diagnose the disease without biopsy if possible, especially in children, because of the surgical invasiveness of the procedure. Recently, serum anti-rabphilin-3A antibodies have attracted attention as diagnostic markers for LYH, especially in LINH, but there are only a few reports on pediatric patients. In the present study, we experienced two children with LPH and LAH, respectively, who tested positive for anti-rabphilin-3A antibodies. This is the first report of children with LYH other than LINH positive for anti-rabphilin-3A antibodies, and anti-rabphilin-3A antibodies may be a useful non-invasive diagnostic marker not only for LINH but also for LYH in general. We also discuss the sensitivity and specificity of anti-rabphilin-3A antibody testing in cases where histological diagnosis has been made.

Central diabetes insipidus with anti-rabphilin-3A antibody positivity causing hypovolemic shock after resection of tumorous lesions in the pelvic cavity.

A 36-year-old female was pointed out to have liver enzyme elevation by routine health checkup. Subsequent contrast-enhanced CT scan identified gigantic uterine fibroids and retroperitoneal tumor. She was referred to the gynecologist at JA Toride Medical Center and planned to undergo a uterus enucleation and biopsy of the retroperitoneal tumor. The surgery was conducted without any troubles. After the surgery, the patient presented polyuria with urine volume 10-20 L a day and developed hypovolemic shock. Laboratory test revealed hypotonic urine and hypernatremia. Arginine vasopressin (AVP) loading test suggested shortage of endogenous vasopressin. Since the subcutaneous administration of AVP was not sufficient to control the urine volume, continuous intravenous infusion of AVP was initiated. After achieving hemodynamic stability, the treatment was switched to oral desmopressin. MRI finding indicated attenuation of high signal in posterior pituitary in T1 weighted image while neither enlargement of pituitary nor thickening of pituitary stalk was indicated by enhanced MRI. Hypertonic salt solution test indicated no responsive elevation of AVP, confirming the diagnosis of central diabetes insipidus (CDI). Her anterior pituitary function was preserved. Only anti-rabphilin-3A antibody was found positive in the serum of the patient, while other secondary causes for CDI were denied serologically and radiologically. Hence, lymphocytic infundibuloneurohypophysitis　(LINH) was suspected as the final diagnosis. Hormonal replacement therapy by nasal desmopressin was continued and the patient managed to control her urine volume. In cases of CDI considered idiopathic with conventional examinations, anti-rabphilin-3A antibody may be a clue for determining the cause as LINH.

Effectiveness of a peer group-based online intervention program in empowering families of children with disabilities at home.

Background: The empowerment of families raising children with disabilities (CWD) is crucial in maintaining their health. We developed an evidence-based, family empowerment intervention program focusing on social resource utilization and reducing care burden. Objective: This study aimed to determine the program's effectiveness in promoting family empowerment. Methods: We compared an intervention group that started the online intervention program a week after initial evaluation and a group that received delayed intervention (waitlist-controlled group) at three time points: initial (T1), post-course (T2), and follow-up (T3). The required sample size was 52. Results: There were 60 participants who applied to the program. One participant dropped out due to scheduling issues, and the others were assigned to either the intervention group (n = 29) or the waitlist-controlled group (n = 30). Those who responded to the baseline questionnaire (T1: 26 from the intervention group; 29 from the waitlist-controlled group) comprised the final sample. Among them, 20 members of the intervention group and 20 of the waitlist-controlled group attended all four sessions (completion rates of 77% and 69%, respectively). The attendance rate for sessions 1-4 was 94%, 89%, 81%, and 83%, respectively. The participant numbers in each session ranged from 5 to 18 per month. The baseline outcome score did not differ between the groups. The primary outcome, family empowerment, measured using the family empowerment scale (FES), was significantly higher at T2 for the intervention group than in the waitlist-controlled group and was sustained in the sensitivity analysis. The intervention group's FES, in the family relationships (FA) and relationships with service systems (SS) subdomains, increased significantly, unlike involvement with the community (SP). The intervention group experienced lower care burden and higher self-compassion, especially in the isolation and over-identification items of the self-compassion scale-short form (SCS-SF). The intervention group's FES (total, FA, SS) and SCS-SF (total, common humanity, isolation) changed significantly between T1 and T2, and all, except common humanity, were sustained up to T3; this group's FES (SP) and SCS (negative score, over-identification) changed significantly between T1 and T3. The waitlist-controlled group's FES (total, FA) and SCS (total) changed significantly and were sustained between T2 and T3. Conclusions: The developed intervention program promotes family empowerment in families of CWD. Clinical Trial Registration: This study is registered as a clinical trial in the UMIN Clinical Trials Registry (https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000050422, UMIN000044172).

Peer group-based online intervention program to empower families raising children with disabilities: protocol for a feasibility study using non-randomized waitlist-controlled trial.

BACKGROUND: Families raising children with disabilities assume risks to their health and lives. Therefore, it is necessary to support these families to improve family empowerment, which is the ability of these families to control their own lives and to promote the collaborative raising of children with disabilities. This is the first online intervention program focusing on the empowerment of families raising children with disabilities who live at home in Japan. METHOD: The program consists of four online peer-based group sessions. Moreover, the families engage in several activities in stages wherein they discover their own issues, find measures to resolve them, and take action, while visualizing interfamily relationships, including social resources, and the status of their family life, with facilitators and other peer members. This study is a non-randomized, waitlist-controlled trial. It compares the results of the intervention group (early group) and the waitlist-controlled group (delayed group). The participants are allocated to the early or delayed group in the order of their applications. The main outcome is family empowerment. Other outcomes are the caregiver burden, self-reported capability to use social resources, self-compassion, and the quality of life (QOL) of primary caregivers. The timeline of the online outcome evaluation is as follows: the initial evaluation (Time 1 [T1]) is conducted before the start of the first early group program, and post-intervention evaluation (Time 2 [T2]) is conducted immediately (within 1 week) after the early group completes all four sessions (4 weeks) of the program. Follow-up evaluation (Time 3 [T3]) is conducted 4 weeks after the post-intervention evaluation. This timing is the same in the delayed group, but the delayed group will attend the program after a 4-week waiting period, compared to the early group. DISCUSSION: The intention is to evaluate whether the provision of the program developed in this study and the evaluation test design are feasible and to verify the efficacy of this program. TRIAL REGISTRATION: The UMIN Clinical Trials Registry (UMIN000044172), registration date: May 19, 2021.

Association of a home-based nursing service during chemotherapy with the transfer to home care immediately after the last chemotherapy treatment in patients with advanced cancer.

BACKGROUND: The appropriate timing of introducing the home-based nursing service to patients with advanced cancer has not been clarified. This study conducted a retrospective cohort study to investigate the associations of the early utilization of the home-based nursing service during chemotherapy with the place of care immediately after the last chemotherapy treatment in patients with advanced cancer. METHODS: Among the patients referred to the palliative care team of the University of Tsukuba Hospital between January 2018 and December 2019, patients with advanced cancer undergoing chemotherapy or before the start of chemotherapy at referral were included. The study patients who utilized the home-based nursing service during chemotherapy were classified into the early utilization group. The primary endpoint was the place of care immediately after the last chemotherapy treatment. RESULTS: Of the 1154 patients referred to the palliative care team during the study period, 261 were eligible for this study. Of these patients, 15.3% of patients (n = 40) received the home-based nursing service during chemotherapy. The proportion of patients transferred to home care after the last chemotherapy treatment was 17.5% in the early utilization group and 7.2% in the control group. The multivariate analysis revealed that the early utilization of the home-based nursing service during chemotherapy was significantly associated with the transfer to home care (odds ratio = 3.077; 95% confidence interval, 1.113-8.502). CONCLUSION: The early utilization of the home-based nursing service during chemotherapy might be associated with the transfer to home care immediately after the last chemotherapy treatment.

Dental pulp stem cells as a therapy for congenital entero-neuropathy.

Hirschsprung's disease is a congenital entero-neuropathy that causes chronic constipation and intestinal obstruction. New treatments for entero-neuropathy are needed because current surgical strategies have limitations5. Entero-neuropathy results from enteric nervous system dysfunction due to incomplete colonization of the distal intestine by neural crest-derived cells. Impaired cooperation between the enteric nervous system and intestinal pacemaker cells may also contribute to entero-neuropathy. Stem cell therapy to repair these multiple defects represents a novel treatment approach. Dental pulp stem cells derived from deciduous teeth (dDPSCs) are multipotent cranial neural crest-derived cells, but it remains unknown whether dDPSCs have potential as a new therapy for entero-neuropathy. Here we show that intravenous transplantation of dDPSCs into the Japanese Fancy-1 mouse, an established model of hypoganglionosis and entero-neuropathy, improves large intestinal structure and function and prolongs survival. Intravenously injected dDPSCs migrate to affected regions of the intestine through interactions between stromal cell-derived factor-1α and C-X-C chemokine receptor type-4. Transplanted dDPSCs differentiate into both pacemaker cells and enteric neurons in the proximal colon to improve electrical and peristaltic activity, in addition to their paracrine effects. Our findings indicate that transplanted dDPSCs can differentiate into different cell types to correct entero-neuropathy-associated defects.

Studies on anti-rabphilin-3A antibodies in 15 consecutive patients presenting with central diabetes insipidus at a single referral center.

Central diabetes insipidus (CDI) is a rare condition caused by various underlying diseases including inflammatory and autoimmune diseases, and neoplasms. Obtaining an accurate definitive diagnosis of the underlying cause of CDI is difficult. Recently, anti-rabphilin-3A antibodies were demonstrated to be a highly sensitive and specific marker of lymphocytic infundibuloneurohypophysitis (LINH). Here, we report a detailed case series, and evaluated the significance of anti-rabphilin-3A antibodies in differentiating the etiologies of CDI. A prospective analysis was conducted in 15 consecutive patients with CDI from 2013 to 2020 at a single referral center. Anti-rabphilin-3A antibodies were measured and the relationship between antibody positivity and the clinical/histopathological diagnoses was evaluated. Among 15 CDI patients, the positive anti-rabphilin-3A antibodies were found in 4 of 5 LINH cases, 3 of 4 lymphocytic panhypophysitis (LPH) cases, one of 2 sarcoidosis cases, and one intracranial germinoma case, respectively. Two Rathke cleft cyst cases and one craniopharyngioma case were negative. This is the first report of anti-rabphilin-3A antibodies positivity in CDI patients with biopsy-proven LPH. Measurement of anti-rabphilin-3A antibodies may be valuable for differentiating CDI etiologies.

A 7-year-old boy with central diabetes insipidus presenting with thickened pituitary stalk and anti-rabphilin-3A antibody positivity.

OBJECTIVES: A highly invasive pathological diagnosis is necessary to differentiate central diabetes insipidus (CDI) with a thickened pituitary stalk. Lymphocytic infundibulo-hypophysitis (LIH) due to autoimmune involvement of the pituitary stalk is a differentiating disease, and anti-rabphilin-3A antibody (Rab3A-Ab) positivity was recently reported. CASE PRESENTATION: A 7-year-old boy was diagnosed with CDI after having polyuria for two months. He showed growth hormone deficiency with reduced growth rate. Brain magnetic resonance imaging (MRI) revealed a thickened pituitary stalk. The placental alkaline phosphatase level of the cerebrospinal fluid, tumor marker for germ cell tumors, was below the level of sensitivity. No skin or bone findings suggestive of Langerhans cell histiocytosis were detected. Eight months after CDI onset, Rab3A-Ab was positive, and MRI showed shrinking of the thickened pituitary stalk, leading to the diagnosis with LIH. CONCLUSIONS: Rab3A-Ab is a useful adjunctive diagnostic tool for childhood-onset LIH.

Lymphocytic panhypophysitis and anti-rabphilin-3A antibody with pulmonary sarcoidosis.

PURPOSE: To explore the clinical significance of anti-rabphillin-3A antibody for the differential diagnosis of lymphocytic panhypophysitis. METHODS AND RESULTS: A 58-year-old Japanese man developed uveitis of unknown cause in 2017. In 2019, he became aware of polyuria. In August 2020, he noticed transient diplopia and was diagnosed with right abducens nerve palsy. At the same time, he complained of fatigue and loss of appetite. Head magnetic resonance imaging demonstrated enlargement of the pituitary stalk and pituitary gland, corresponding to hypophysitis. Hormone stimulation tests showed blunted responses with respect to all anterior pituitary hormones. Central diabetes insipidus was diagnosed on the basis of a hypertonic saline loading test. Taking these findings together, a diagnosis of panhypopituitarism was made. Computed tomography showed enlargement of hilar lymph nodes. Biopsies of the hilar lymph nodes revealed non-caseating epithelioid cell granulomas that were consistent with sarcoidosis. Biopsy of the anterior pituitary revealed mild lymphocyte infiltration in the absence of IgG4-positive cells, non-caseating granulomas, or neoplasia. Western blotting revealed the presence of anti-rabphilin-3A antibody, supporting a diagnosis of lymphocytic panhypophysitis. Because the patient had no visual impairment or severe uveitis, we continued physiological hormone replacement therapy and topical steroid therapy for the uveitis. CONCLUSION: To the best of our knowledge, this is the first case of anti-rabphilin 3A antibody positive lymphocytic panhypophysitis comorbid with sarcoidosis, diagnosed by both pituitary and hilar lymph node biopsy. The utility of anti-rabphilin-3A antibody for the differential diagnosis of hypophysitis like this case should be clarified with further case studies.

Ketoacidosis, Hypertriglyceridemia and Acute Pancreatitis Induced by Soft Drink Polydipsia in a Patient with Occult Central Diabetes Insipidus.

A 21-year-old Japanese man without known diabetes mellitus had abdominal pain. The diagnosis was ketoacidosis and hypertriglyceridemia-induced acute pancreatitis. He had polydipsia and polyuria and had habitually drunk several soft drinks every day for two years. After hospitalization, despite adequate liquid intake, dehydration remained with hypotonic polyuria. Further examinations revealed the coexistence of central diabetes insipidus (CDI), possibly caused by lymphocytic infundibulo-neurohypophysitis, based on anti-rabphilin-3A antibody positivity. Although CDI had been undiagnosed for two years, over-consumption of sugar-rich soft drinks to ease thirst caused ketoacidosis, hypertriglyceridemia, and acute pancreatitis. There are no previous reports of this three-part combination of symptoms caused by CDI.

A SARS-CoV-2 antibody broadly neutralizes SARS-related coronaviruses and variants by coordinated recognition of a virus-vulnerable site.

Potent neutralizing SARS-CoV-2 antibodies often target the spike protein receptor-binding site (RBS), but the variability of RBS epitopes hampers broad neutralization of multiple sarbecoviruses and drifted viruses. Here, using humanized mice, we identified an RBS antibody with a germline VH gene that potently neutralized SARS-related coronaviruses, including SARS-CoV and SARS-CoV-2 variants. X-ray crystallography revealed coordinated recognition by the heavy chain of non-RBS conserved sites and the light chain of RBS with a binding angle mimicking the angiotensin-converting enzyme 2 (ACE2) receptor. The minimum footprints in the hypervariable region of RBS contributed to the breadth of neutralization, which was enhanced by immunoglobulin G3 (IgG3) class switching. The coordinated binding resulted in broad neutralization of SARS-CoV and emerging SARS-CoV-2 variants of concern. Low-dose therapeutic antibody treatment in hamsters reduced the virus titers and morbidity during SARS-CoV-2 challenge. The structural basis for broad neutralizing activity may inform the design of a broad spectrum of therapeutics and vaccines.

Multidisciplinary pharmacotherapy collaboration for home-based older adults with dementia: a study focusing on physicians, pharmacists, and nursing professionals.

BACKGROUND: It is imperative that a team consisting of a physician, pharmacist, and nursing professional provides pharmacotherapy support to achieve the optimal effect of pharmacotherapy for older adults with dementia. This study reviewed Japanese publications on the process of pharmacotherapy support practised by various professionals for home-based older adults with dementia and investigated healthcare professionals' perceived importance and practice of pharmacotherapy support. METHODS: This study aimed to shed light on basic pharmacotherapy support for behavioural and psychological symptoms among home-based older adults with dementia using multidisciplinary collaboration, through a literature review of Japanese publications. Based on the literature review, 13 items pertaining to basic pharmacotherapy support for home-based older adults with dementia were extracted. A mail-based, self-administered, anonymous questionnaire survey was conducted with professionals including physicians, pharmacists, and nursing professionals who provide pharmacotherapy support to home-based older adults with dementia. Participants rated 13 items on their perceived importance and practice of basic pharmacotherapy support using a four-point Likert scale. RESULTS: The results indicated that participants recognised the importance of all 13 items. At least 80% of all professionals indicated that they practised seven out of 13 items. Less than 80% of all professionals indicated they practised the other six items that should be provided after the commencement of pharmacotherapy. A relatively high proportion of nursing professionals (70%) indicated they practised the remaining six items. The 13 items were indeed deemed important for characterising pharmacotherapy support. However, in Japan, suboptimal support is provided following the commencement of medication. This may be because appropriate modifications to dementia care are not made as the patient's condition progresses. CONCLUSIONS: It is suggested that multidisciplinary collaboration focusing on the progression of dementia and the process of pharmacotherapy, especially after the commencement of pharmacotherapy, may help provide effective, continuous pharmacotherapy.

Critical role of rabphilin-3A in the pathophysiology of experimental lymphocytic neurohypophysitis.

Autoimmune hypophysitis (AH) is thought to be an autoimmune disease characterized by lymphocytic infiltration of the pituitary gland. Among AH pathologies, lymphocytic infundibulo-neurohypophysitis (LINH) involves infiltration of the neurohypophysis and/or the hypothalamic infundibulum, causing central diabetes insipidus resulting from insufficiency of arginine vasopressin secretion. The pathophysiological and pathogenetic mechanisms underlying LINH are largely unknown. Clinically, differentiating LINH from other pituitary diseases accompanied by mass lesions, including tumours, has often been difficult, because of similar clinical manifestations. We recently reported that rabphilin-3A is an autoantigen and that anti-rabphilin-3A antibodies constitute a possible diagnostic marker for LINH. However, the involvement of rabphilin-3A in the pathogenesis of LINH remains to be elucidated. This study was undertaken to explore the role of rabphilin-3A in lymphocytic neurohypophysitis and to investigate the mechanism. We found that immunization of mice with rabphilin-3A led to neurohypophysitis. Lymphocytic infiltration was observed in the neurohypophysis and supraoptic nucleus 1 month after the first immunization. Mice immunized with rabphilin-3A showed an increase in the volume of urine that was hypotonic as compared with control mice. Administration of a cocktail of monoclonal anti-rabphilin-3A antibodies did not induce neurohypophysitis. However, abatacept, which is a chimeric protein that suppresses T-cell activation, decreased the number of T cells specific for rabphilin-3A in peripheral blood mononuclear cells (PBMCs). It ameliorated lymphocytic infiltration of CD3+ T cells in the neurohypophysis of mice that had been immunized with rabphilin-3A. Additionally, there was a linear association between the number of T cells specific for rabphilin-3A in PBMCs and the number of CD3+ T cells infiltrating the neurohypophysis. In conclusion, we suggest that rabphilin-3A is a pathogenic antigen, and that T cells specific for rabphilin-3A are involved in the pathogenesis of neurohypophysitis in mice. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Cullin-associated NEDD8-dissociated protein 1, a novel interactor of rabphilin-3A, deubiquitylates rabphilin-3A and regulates arginine vasopressin secretion in PC12 cells.

The molecular mechanism involved in the exocytosis of arginine vasopressin (AVP) is not fully known. Rabphilin-3A has been suggested as a novel autoantigen in infundibulo-neurohypophysitis (LINH), which leads to central diabetes insipidus through insufficient secretion of AVP. However, the role of rabphilin-3A in the pathogenesis of LINH remains unclear. Thus, the aim of the present study was to identify proteins binding rabphilin-3A in the posterior pituitary. Using glutathione S-transferase (GST)-pulldown assays and proteomic analyses, cullin-associated NEDD8-dissociated protein 1 (CAND1) was identified as a rabphilin-3A-binding protein in the posterior pituitary. Co-immunoprecipitation assays indicated that CAND1 interacted endogenously with rabphilin-3A. In addition, immunohistochemistry experiments showed that CAND1 immunoreactivity was detected mainly in the posterior pituitary, intermediate lobe, and the supraoptic nucleus in the hypothalamus, and less in the anterior lobe, partially co-localizing with rabphilin-3A. Overexpression of CAND1 resulted in deubiquitylation of rabphilin-3A in PC12 cells. Moreover, overexpression of CAND1 in PC12 cells co-transfected with AVP enhanced both basal and KCl-stimulated AVP secretion. The findings indicate that CAND1 inhibits the ubiquitylation of rabphilin-3A and positively regulates AVP secretion. These data shed light on a novel potential mechanism involving rabphilin-3A in AVP secretion, and suggest a new role of CAND1 as a regulator of hormone or neurotransmitter secretion.

Dialysis membrane-enforced microelectrode array measurement of diverse gut electrical activity.

A variety of electrical activities occur depending on the functional state in each section of the gut, but the application of microelectrode array (MEA) is rather limited. We thus developed a dialysis membranes-enforced technique to investigate diverse and complex spatio-temporal electrical activity in the gut. Muscle sheets isolated from the gastrointestinal (GI) tract of mice along with a piece of dialysis membrane were woven over and under the strings to fix them to the anchor rig, and mounted on an 8×8 MEA (inter-electrode distance=150µm). Small molecules (molecular weight <12,000) were exchanged through the membrane, maintaining a physiological environment. Low impedance MEA was used to measure electrical signals in a wide frequency range. We demonstrated the following examples: 1) pacemaker activity-like potentials accompanied by bursting spike-like potentials in the ileum; 2) electrotonic potentials reflecting local neurotransmission in the ileum; 3) myoelectric complex-like potentials consisting of slow and rapid oscillations accompanied by spike potentials in the colon. Despite their limited spatial resolution, these recordings detected transient electric activities that optical probes followed with difficulty. In Addition, propagation of pacemaker-like potential was visualized in the stomach and ileum. These results indicate that the dialysis membrane-enforced technique largely extends the application of MEA, probably due to stabilisation of the access resistance between each sensing electrode and a reference electrode and improvement of electric separation between sensing electrodes. We anticipate that this technique will be utilized to characterise spatio-temporal electrical activities in the gut in health and disease.