Piezo1 regulates meningeal lymphatic vessel drainage and alleviates excessive CSF accumulation.

Piezo1 regulates multiple aspects of the vascular system by converting mechanical signals generated by fluid flow into biological processes. Here, we find that Piezo1 is necessary for the proper development and function of meningeal lymphatic vessels and that activating Piezo1 through transgenic overexpression or treatment with the chemical agonist Yoda1 is sufficient to increase cerebrospinal fluid (CSF) outflow by improving lymphatic absorption and transport. The abnormal accumulation of CSF, which often leads to hydrocephalus and ventriculomegaly, currently lacks effective treatments. We discovered that meningeal lymphatics in mouse models of Down syndrome were incompletely developed and abnormally formed. Selective overexpression of Piezo1 in lymphatics or systemic administration of Yoda1 in mice with hydrocephalus or Down syndrome resulted in a notable decrease in pathological CSF accumulation, ventricular enlargement and other associated disease symptoms. Together, our study highlights the importance of Piezo1-mediated lymphatic mechanotransduction in maintaining brain fluid drainage and identifies Piezo1 as a promising therapeutic target for treating excessive CSF accumulation and ventricular enlargement.

Piezo1-Regulated Mechanotransduction Controls Flow-Activated Lymphatic Expansion.

BACKGROUND: Mutations in PIEZO1 (Piezo type mechanosensitive ion channel component 1) cause human lymphatic malformations. We have previously uncovered an ORAI1 (ORAI calcium release-activated calcium modulator 1)-mediated mechanotransduction pathway that triggers lymphatic sprouting through Notch downregulation in response to fluid flow. However, the identity of its upstream mechanosensor remains unknown. This study aimed to identify and characterize the molecular sensor that translates the flow-mediated external signal to the Orai1-regulated lymphatic expansion. METHODS: Various mutant mouse models, cellular, biochemical, and molecular biology tools, and a mouse tail lymphedema model were employed to elucidate the role of Piezo1 in flow-induced lymphatic growth and regeneration. RESULTS: Piezo1 was found to be abundantly expressed in lymphatic endothelial cells. Piezo1 knockdown in cultured lymphatic endothelial cells inhibited the laminar flow-induced calcium influx and abrogated the flow-mediated regulation of the Orai1 downstream genes, such as KLF2 (Krüppel-like factor 2), DTX1 (Deltex E3 ubiquitin ligase 1), DTX3L (Deltex E3 ubiquitin ligase 3L,) and NOTCH1 (Notch receptor 1), which are involved in lymphatic sprouting. Conversely, stimulation of Piezo1 activated the Orai1-regulated mechanotransduction in the absence of fluid flow. Piezo1-mediated mechanotransduction was significantly blocked by Orai1 inhibition, establishing the epistatic relationship between Piezo1 and Orai1. Lymphatic-specific conditional Piezo1 knockout largely phenocopied sprouting defects shown in Orai1- or Klf2- knockout lymphatics during embryo development. Postnatal deletion of Piezo1 induced lymphatic regression in adults. Ectopic Dtx3L expression rescued the lymphatic defects caused by Piezo1 knockout, affirming that the Piezo1 promotes lymphatic sprouting through Notch downregulation. Consistently, transgenic Piezo1 expression or pharmacological Piezo1 activation enhanced lymphatic sprouting. Finally, we assessed a potential therapeutic value of Piezo1 activation in lymphatic regeneration and found that a Piezo1 agonist, Yoda1, effectively suppressed postsurgical lymphedema development. CONCLUSIONS: Piezo1 is an upstream mechanosensor for the lymphatic mechanotransduction pathway and regulates lymphatic growth in response to external physical stimuli. Piezo1 activation presents a novel therapeutic opportunity for preventing postsurgical lymphedema. The Piezo1-regulated lymphangiogenesis mechanism offers a molecular basis for Piezo1-associated lymphatic malformation in humans.

Experience of Insomnia Symptoms in the Elderly Living Alone in the Community / 정신간호학회지

Purpose@#The purpose of this study was to identify the experiences of insomnia symptoms in the elderly living alone in the community. @*Methods@#Eleven of the elderly with insomnia symptoms living alone in the community were interviewed. Data were collected through individual interviews July-September 2018. Colaizzi’s phenomenological methodology was used. @*Results@#Results showed that the experiences of insomnia symptoms of the elderly living alone comprised 11 themes clusters and five categories: 1) Insomnia symptoms triggered by various causes, 2) Physical symptoms exacerbated by insomnia, 3) Insomnia worsened by psychological symptoms, 4) Useless efforts to fix insomnia, 5) Living with adapted insomnia symptoms. @*Conclusion@#It is necessary to develop a sleep intervention program that includes insomnia symptoms awareness, sleep health education, and social support factors. Community nurses should focus on insomnia symptoms as well as listen and empathize with various psychological phenomena in caring for the elderly with insomnia living alone.

Recurrent Primary Signet Ring Cell Cancer of the Colon at Anastomosis Site after Curative Resection

A primary signet ring cell cancer (SRCC) is a rare form of an adenocarcinoma of the large intestine. The prognosis of SRCC of the colon has been reported to be worse than classic adenocarcinoma of the colon; however, there is no difference in the post-operative surveillance for SRCC. We report a case of SRCC of the colon with negative resection margins that recurred at the anastomosis site 26 months after curative resection. A 55-year-old male presented to the hospital with abdominal pain. The initial colonoscopy and abdominal computed tomography revealed SRCC of the proximal ascending colon. He underwent extensive curative surgical resection and adjuvant chemotherapy for 8 months. However, 26 months post-operatively, the cancer recurred at the anastomosis site without peritoneal dissemination. Physicians should be aware that SRCC may have different recurrence patterns compared with classic adenocarcinoma, and may need more vigorous surveillance, even after curative surgery.

Recurrent Primary Signet Ring Cell Cancer of the Colon at Anastomosis Site after Curative Resection

A primary signet ring cell cancer (SRCC) is a rare form of an adenocarcinoma of the large intestine. The prognosis of SRCC of the colon has been reported to be worse than classic adenocarcinoma of the colon; however, there is no difference in the post-operative surveillance for SRCC. We report a case of SRCC of the colon with negative resection margins that recurred at the anastomosis site 26 months after curative resection. A 55-year-old male presented to the hospital with abdominal pain. The initial colonoscopy and abdominal computed tomography revealed SRCC of the proximal ascending colon. He underwent extensive curative surgical resection and adjuvant chemotherapy for 8 months. However, 26 months post-operatively, the cancer recurred at the anastomosis site without peritoneal dissemination. Physicians should be aware that SRCC may have different recurrence patterns compared with classic adenocarcinoma, and may need more vigorous surveillance, even after curative surgery.

A Case of Early-stage Squamous Cell Carcinoma of the Anal Canal Diagnosed by Endoscopic Mucosal Resection / 대한소화기내시경학회지

In the past, abdominoperineal resection was routinely performed for anal canal cancer, yet it is now known that squamous cell carcinoma of the anal canal has a favorable prognosis and it rarely requires radical surgery. Furthermore, T1 anal cancer, which represents about 10% of all anal canal cancers, has an excellent prognosis. Endoscopic mucosal resection (EMR), which has been used for removal of early-stage adenocarcinoma of the rectum, has not been reported as a treatment option for squamous cell carcinoma of the anal canal because making the endoscopic diagnosis of early-stage anal canal cancer is very difficult. We have experienced a case of early-stage squamous cell carcinoma of the anal canal that was identified without symptoms during routine screening colonoscopy and it was removed by EMR. As far as we know, it is the first case of early-stage anal canal cancer that was diagnosed and treated by endoscopic mucosal resection.

Case Review of Impacted Bile Duct Stone at Duodenal Papilla: Detection and Endoscopic Treatment

PURPOSE: A bile duct stone impacted at the duodenal papilla is an urgent condition that can rapidly lead to either suppurative cholangitis or acute pancreatitis due to almost complete obstruction of the bilio-pancreatic outflow. This study evaluated the clinical characteristics and results of endoscopic treatment for a bile duct stone impacted at the duodenal papilla. MATERIALS AND METHODS: Forty-six patients who had been diagnosed with an impacted papillary stone were retrospectively reviewed. RESULTS: The typical features of acute cholangitis (Charcot's triad) and pancreatitis were only observed only in 10 patients (21.7%) and 17 patients (37.0%), respectively. After the endoscopic retrograde cholangiopancreatography, 30 patients (65.2%) were found to have a solitary stone impacting the duodenal papilla and 16 patients had one or more stones in the bile duct. On the radiological studies, the former patients were associated more commonly with no visible stone or no bile duct dilatation (p < 0.05). All impacted papillary stones were successfully removed by endoscopic sphincterotomy: 23 by a needle knife and 23 by a pull type papillotome. The procedure-related complications (n = 7, 4 bleeding, 3 pancreatitis) were not serious and did not differ, based on endoscopic findings and the procedure used. CONCLUSION: A bile duct stone impacted at the duodenal papilla requires both clinical and radiographic evidence to support the diagnosis. Endoscopic sphincterotomy, either with a needle knife or a pull type papillotome, was safe and effective for removing the impacted papillary stone.

A Case of Bleeding from a Jejunal Gastrointestinal Stromal Tumor Diagnosed by Double Balloon Enteroscopy / 대한소화기내시경학회지

Gastrointestinal bleeding from a small bowel lesion is uncommon, but it is the most common cause of obscure gastrointestinal bleeding and it can go undiagnosed using traditional upper endoscopy and colonoscopy. Recently, capsule endoscopy and double-balloon enteroscopy (DBE) were developed as new techniques for visualization of the entire small intestine and have improved access to the lesion site in patients with obscure gastrointestinal bleeding. In this report, we describe a 49-year male presenting with melena from a gastrointestinal stromal tumor (GIST) of the proximal jejunum that was diagnosed by DBE and resected by laparoscopic surgery.

Elevated level of serum tryptase in a patient with exercise-inuced anaphylaxis / 천식및알레르기

Exercise-induced anaphylaxis (EIA) is a medical emergency in that it derives from a physical allergy. We reported a case of food-independent EIA based on history and laboratory data. A 40-year-old male patient was presented with generalized urticaria, angioedema, and syncope after jogging. He had suffered from allergic rhinitis for 25 years. Increased level of serum tryptase was noted. Mast cell activation might be suggested in the pathophysiologic mechanism of EIA.

Acute and Chronic Changes of Vascular Endothelial Growth Factor (VEGF)in Induced Sputum of Toluene Diisocyanate (TDI)-induced Asthma Patients

Vascular endothelial growth factor (VEGF) is a multi-functional cytokine involved in inflammation, repair and angiogenesis in asthmatic airway. This study aimed to evaluate the role of VEGF in immediate bronchoconstriction induced by TDI inhalation, and in chronic TDI-asthma patients. 11 newly diagnosed TDI-asthma patients (group I), 12 chronic TDI-asthma patients with persistent asthma symptoms followed for >4 yr and 15 unexposed healthy controls were enrolled. In group I, induced sputum and serum were collected before and 7 hr after placebo- and TDI-bronchoprovocation test (BPT). In group II, induced sputum and serum were collected every 2 yr. VEGF levels were measured by ELISA. There were no significant differences in sputum and serum VEGF levels between patients and controls. Before and after placebo and TDI-BPT, no significant changes were noted in sputum and serum VEGF levels of group I. In group II patients, sputum VEGF showed variable changes at 1-yr, then decreased significantly at 2-yr (p<0.05), while serum VEGF showed variable changes at 2-yr, which decreased significantly at 4-yr (p<0.05). These results suggest that VEGF may play a minor role in immediate bronchoconstriction after TDI-BPT. In chronic TDI-asthma, VEGF may be involved to 2 yr after the diagnosis and the contribution may decrease after then.