Associations among plasma markers for N-methyl-d-aspartate receptor hypofunction, redox dysregulation, and insufficient myelination in patients with schizophrenia.

Background: Several hypotheses regarding the pathomechanisms of schizophrenia have been proposed. If schizophrenia is a unitary disease, then these pathological processes must be linked; however, if such links do not exist, schizophrenia may best be considered a group of disorders. Only a few studies have examined the relationships among these pathomechanisms. Herein, we examined the relationships among deficient myelination, NMDA receptor hypofunction, and metabolic dysregulation by measuring various plasma markers and examining their correlations. Methods: Plasma samples were collected from 90 patients with schizophrenia and 68 healthy controls. Concentrations of nardilysin (N-arginine dibasic convertase, NRDC), a positive regulator of myelination, the NMDA receptor co-agonist d-serine and glycine, various additional amino acids related to NMDA receptor transmission (glutamate, glutamine, and l-serine), and homocysteine (Hcy), were measured. Concentrations were compared using independent samples t-test or logistic regression, and associations were evaluated using Pearson's correlation coefficients. Results: Plasma glycine (t = 2.05, p = 0.042), l-serine (t = 2.25, p = 0.027), and homocysteine (t = 3.71, p < 0.001) concentrations were significantly higher in patients with schizophrenia compared to those in healthy controls. Logistic regression models using age, sex, smoking status, glutamine, glutamate, glycine, l-serine, d-serine, homocysteine, and NRDC as independent variables revealed significantly lower plasma d-serine (p = 0.024) and NRDC (p = 0.028), but significantly higher l-serine (p = 0.024) and homocysteine (p = 0.001) in patients with schizophrenia. Several unique correlations were found between NMDA receptor-related amino acids and NRDC in patients with schizophrenia compared to those in healthy controls, while no correlations were found between plasma homocysteine and other markers. No associations were found between plasma marker concentrations and disease status or cognitive function in patients with schizophrenia, except for a significant correlation between plasma glycine and full intelligence quotient. Conclusion: Reduced myelination and NMDA receptor hypofunction may be related to pathological mechanisms in schizophrenia, while homocysteine dysregulation appears to be an independent pathological process. These results suggest that schizophrenia may be a group of disorders with unique or partially overlapping etiologies.

Laparoscopic cholecystectomy and common bile duct exploration for gallstone and common bile duct stone in a patient with a left-sided gallbladder: a case report.

Left-sided gallbladder is a rare finding that is mostly discovered incidentally during surgery and is often associated with anatomic anomalies. We herein report a case in which laparoscopic cholecystectomy and common bile duct exploration were achieved for an 89-year-old female patient with left-sided gallbladder. Surgery was carried out using our usual trocar position. Calot triangle was covered by the body of the gallbladder and could not be detected. We dissected the gallbladder from the fundus towards the neck. The cystic duct joined the common bile duct from the right side, and common bile duct exploration was performed routinely without perioperative comorbidities. Although the preoperative diagnosis rate is low and the risk of intraoperative bile duct injuries in patients with left-sided gallbladder is high, laparoscopic cholecystectomy and common bile duct exploration can be safely performed by understanding the location and bifurcation of the cystic duct.

Acute cholecystitis with sepsis due to Edwardsiella tarda: a case report.

BACKGROUND: Edwardsiella tarda (E. tarda) is a Gram-negative facultative anaerobe belonging to Enterobacteriales and is commonly isolated from fishes and reptiles. Infection due to E. tarda is uncommon among humans, with a reported human retention rate of 0.001%. It can cause sepsis in the elderly or those with pre-existing conditions such as liver failure, autoimmune disease, or malignancy. E. tarda is susceptible to many antibiotics; however, a high mortality rate (approximately 40%) has been reported with sepsis. CASE PRESENTATION: A 65-year-old woman presented to our hospital with a chief complaint of fever and abdominal pain for 2 days. Her blood tests showed elevated inflammatory markers, and contrast-enhanced computed tomography showed distention and wall thickening of the gallbladder and inflammation of peri-gallbladder fat. Subsequently, a diagnosis of cholecystitis with systemic inflammatory response syndrome was made. Laparoscopic cholecystectomy was performed after starting antimicrobial therapy. Blood culture of samples obtained on admission were positive for E. tarda, which was also detected in bile juice culture. Therefore, she was diagnosed with bacteremia caused by E. tarda, and postoperative antimicrobial therapy was continued. The patient improved, and there were no complications. CONCLUSIONS: We experienced an extremely rare case of acute cholecystitis caused by E. tarda. Only a few cases of acute cholecystitis due to E. tarda have been reported. Furthermore, similar to this case, no previous study has reported the detection of E. tarda in both blood and bile cultures in acute cholecystitis cases. In addition to appropriate surgical intervention, continuous administration of antibiotics based on culture results resulted in a favorable outcome.

Nonsmoking after simultaneous alcohol abstinence and smoking cessation program was associated with better drinking status outcome in Japanese alcohol-dependent men: A prospective follow-up study.

BACKGROUND: Growing evidence suggests that intervention for smoking cessation enhances alcohol abstinence in treatment settings for alcohol dependence. However, research in this field is rare in Asians. METHOD: We prospectively investigated the association of smoking status with drinking status using 9 surveys mailed during a 12-month period in 198 Japanese alcohol-dependent men (70 never/ex-smokers and 128 smokers) who admitted for the first time and completed a 3-month inpatient program for simultaneous alcohol abstinence and smoking cessation. RESULTS: Nonsmoking during the first month after discharge and at the end of follow-up was reported in 28.9% and 25.0% of the baseline smokers, respectively. Kaplan-Meier estimates showed that a 12-month alcohol abstinence and heavy-drinking-free status were more frequent among never/ex-smokers (45.1% and 59.8%, respectively) and baseline smokers who quit smoking during the first month after discharge (59.0% and 60.8%, respectively), compared with sustained smokers (30.0% and 41.2%, respectively). Among the baseline smokers, the multivariate odds ratio (95% confidence interval) for smoking cessation during the first month were 2.77 (1.01-7.61) for alcohol abstinence during the period and 2.50 (1.00-6.25) for use of varenicline, a smoking cessation agent, during the inpatient program. After adjusting for age, drinking profile, lifestyle, family history of heavy or problem drinking, lifetime episodes of other major psychiatric disorders, and medications at discharge, the multivariate hazard ratios (HRs) for drinking lapse were 0.57 (0.37-0.89) for the never/ex-smoking and 0.41 (0.23-0.75) for new smoking cessation groups, respectively, compared with sustained smoking, while the corresponding HRs for heavy-drinking lapse were 0.55 (0.33-0.90) and 0.47 (0.25-0.88), respectively. The HR for drinking lapse was 0.63 (0.42-0.95) for the nonsmoking group (vs. smoking) during the observation period, while the HR for heavy-drinking lapse was 0.58 (0.37-0.91) for the nonsmoking group (vs. smoking) during the observation period. Other significant variables that worsened drinking outcomes were higher daily alcohol intake prior to hospitalization, family history of heavy or problem drinking and psychiatric medications at discharge. CONCLUSION: Nonsmoking was associated with better outcomes on the drinking status of Japanese alcohol-dependent men, and a smoking cessation program may be recommended to be integrated into alcohol abstinence programs.

[A Case of Resection of Locally Advanced Ascending Colon Cancer in an Elderly Patient with Parkinson's Disease].

The case presented here is of a man in his 80s who was attending the Department of Neurology for Parkinson's disease. He had a fever and visited the emergency department. A CT scan revealed a 10 cm mass in the hepatic flexure that was suspected of invading the duodenum, as well as numerous enlarged lymph nodes around the mass. A colonoscopy revealed a semi-peripheral type 3 tumor, and a biopsy showed adenocarcinoma(tub1-tub2). A right hemicolectomy was performed, and the tumor was located in the hepatic flexure of the ascending colon and was found to be in a mass with lymph nodes and adhesions to the duodenum. Due to the invasiveness of the surgery and the decrease in ADL, the patient's postoperative course required prolonged hospitalization. He was transferred to the hospital at POD33 and discharged at POD64. Due to his old age, adjuvant chemotherapy was not administered, and he is still alive 1 year after surgery with no recurrence. Even though his hospital stay was prolonged due to his decreased ADL, he is now able to return home. Aggressive resection may provide good results even in elderly patients.

A case of perforated immune-related colitis complicated by cytomegalovirus infection during treatment of immune-related adverse effect in lung cancer immunotherapy.

Although immune checkpoint inhibitors (ICIs) can be used for lung cancer treatment, the activated immune response may cause immune-related adverse effects (irAEs). We present here a case of cytomegalovirus (CMV) enterocolitis during steroid therapy for an irAE. A 70-year-old man diagnosed with small-cell lung carcinoma (limited disease) received radiotherapy plus two chemotherapy cycles of cisplatin and etoposide. The tumor exhibited complete response but recurred after 3 years. After treatment with two cycles of carboplatin, etoposide, and atezolizumab, an inhibitors of programmed cell death receptor-1, he was switched to atezolizumab every 3 weeks for maintenance therapy. Diarrhea occurred after nine atezolizumab doses. With a strong suspicion of ICI-induced colitis, we administered methylprednisolone 500 mg for 3 days, followed by oral prednisolone 40 mg/day. Total colonoscopy during the treatment revealed mucosal inflammation of the total colon, suggesting immune-related colitis. Biopsies from the ulceration revealed crypt abscess with highly infiltrative plasma cells and lymphocytes. Furthermore, immunohistochemical staining showed positivity for CMV. With no improvement in watery diarrhea, the prednisolone dose was increased to 80 mg/day on the 11th day, and ganciclovir was additionally administered twice daily on the 26th day. On the 28th day, the patient had abdominal pain, and abdominal computed tomography revealed free air, resulting in the diagnosis of colon perforation. He underwent subtotal colectomy followed by ileostomy as emergency surgery. A colon specimen revealed colitis with CMV infection. We describe colon perforation in a patient with CMV enterocolitis complicated by refractory immune-related colitis.

[Two Cases of Aortitis Caused by Pegfilgrastim Administered during Chemotherapy for Breast Cancer].

Granulocyte colony-stimulating factor(G-CSF)is known to cause bone pain, headache, and fatigue as side effects. We experienced 2 cases of aortitis caused by pegfilgrastim(PEG-G)administration. Case 1: A 50s woman with breast cancer started FEC therapy with PEG-G as neoadjuvant chemotherapy. She developed a fever in the 38℃ range, and chest CT showed wall thickening in the aortic arch. She was diagnosed with aortitis and administration of prednisolone was started, and the fever resolved and the general condition improved dramatically. Case 2: A 70s woman was started TC therapy with PEG-G as adjuvant chemotherapy after surgery. Fever, anorexia, and epigastralgia appeared. A CT scan of the abdomen revealed thickening of the abdominal aortic wall from the thoracoabdominal transition area to the renal artery bifurcation. She was diagnosed with PEG-G-induced aortitis, and administration of prednisolone was started. The fever resolved and the pain disappeared. Although the symptoms of G-CSF-induced aortitis are nonspecific, it is relatively easy to diagnose by CT and should be considered when a fever develops after G-CSF administration.

Accidental duodenal foreign body of toothbrush removed laparoscopically: a case report.

BACKGROUND: Foreign body ingestion is a common case in daily medical care, and it usually passes through the entire gastrointestinal tract naturally and is excreted in the feces. However, long and sharp foreign bodies may be difficult to pass naturally due to their shape. Here, we present a rare case of a duodenal foreign body, a toothbrush, that required laparoscopic surgical removal after a failed endoscopic attempt. CASE PRESENTATION: A 51-year-old male with intellectual disability presented to our hospital due to fever. Initially, he was diagnosed with aspiration pneumonia by chest X-ray and blood examination. However, abdominal X-ray examination suggested a foreign body, and a computed tomography scan revealed a toothbrush in the duodenum. Therefore, upper gastrointestinal endoscopy was immediately attempted to remove it, but it could not be safely removed because the handle part of the toothbrush seemed deeply embedded in the duodenal mucosa. Therefore, this case was diagnosed as duodenal incarceration of the toothbrush, and it was removed by laparoscopic surgery. The operation was performed safely, and the patient's postoperative course was good without any complications. The extracted toothbrush was 15 cm in length. CONCLUSION: We experienced a rare case of a duodenal foreign body, which was a toothbrush. The duodenal foreign body was safely removed by laparoscopic surgery for the first time.

[A Case in Which Inferior Vena Cava Stent Placement Was Effective for Inferior Vena Cava Stenosis Due to Metastatic Liver Tumor].

A 60s woman was diagnosed with cecal cancer with multiple liver metastases(final pathology was T4aN1M1[H1])and underwent ileocecal resection and D3 dissection. She did not wish for postoperative chemotherapy and surgical treatment of liver metastases. One and a half years after surgery, she developed extremity edema of lower legs and hypoalbuminemia, and she gained 20 kg. Contrast-enhanced CT showed stenosis of the inferior vena cava due to liver metastases, which was markedly improved the symptoms by placement of an inferior vena cava stent. Inferior vena cava stent placement is a minimally invasive treatment and can be an option as it can be expected to improve quality of life in some cases.

[Eight Cases of Breast Cancer That Relapsed More Than Ten Years after Initial Treatment].

Recurrence is more common for breast cancer than other solid tumors. In the last 5 years, we experienced 8 cases that relapsed more than 10 years after initial treatment. All cases were hormone-sensitive and HER2-negative. The Ki-67 percentage score was less than 15% in 7 cases. The age range at recurrence was 56-93 years(mean, 74.6 years), and the time to recurrence was 10-14 years and 20 or more years in 6 and 2 cases(mean, 14.6 years), respectively. The triggers for diagnosis were subjective symptoms, follow-up, and examination for other diseases in 3, 3, and 2 cases, respectively. The recurrence sites included the axilla, pleura/lung, liver/lung, skin, and chest wall in 3, 2, 1, 1, and 1 case, respectively. Treatment included an aromatase inhibitor(AI)and AI plus CDK4/6 inhibitor in 5 and 3 cases, respectively. The post-recurrence treatment period was 6-31 months(mean, 21.6 months), with 4 cases of PR, 3 cases of SD, and 1 case of death from other disease. There were 3 cases of axillary recurrence and 1 case each of neuropathic pain, upper limb edema, and local pain; all were alleviated by the treatment. In 2 cases, the pleural effusion decreased without chest tube drainage. Hormone receptor- positive late-relapse cases are generally highly therapeutically sensitive with favorable prognosis. In many cases, AI alone was selected considering patient age, side effects, treatment costs, and other factors.

[Rapid Recurrence of Dedifferentiated Liposarcoma of Occult Primary in the Abdomen-A Case Report].

A man in his 70s was referred to our hospital for the examination of an abdominal tumor detected incidentally. The tumor was resected with a preoperative diagnosis of gastric submucosal tumor. As a result of the histopathological examination, dedifferentiated liposarcoma was diagnosed. The tumor recurred 2 months after the operation, and resection was attempted again. However, the intraoperative findings showed multiple metastatic lesions, and radical resection was considered impossible. Chemotherapy was therefore administered with doxorubicin monotherapy and eribulin, but the tumor rapidly increased, and the patient ultimately died 8 months after the initial operation. Dedifferentiated liposarcoma is a histologic type with a poor prognosis among liposarcoma. Resection is the standard treatment, but it frequently develops in the retroperitoneum, and it is often found in an advanced state due to the lack of subjective symptoms compared to lesions of the extremities. In addition, its tendency to infiltrate into the surrounding area and to metastasize are also factors that make radical resection difficult. We herein report a case of dedifferentiated liposarcoma that was detected asymptomatically but had a rapid outcome.

Identification and functional characterization of a Siglec-7 counter-receptor on K562 cells.

Sialic acid (Sia)-binding immunoglobulin-like lectin 7 (Siglec-7) is an inhibitory receptor primarily expressed on natural killer (NK) cells and monocytes. Siglec-7 is known to negatively regulate the innate immune system through Sia binding to distinguish self and nonself; however, a counter-receptor bearing its natural ligand remains largely unclear. Here, we identified a counter-receptor of Siglec-7 using K562 hematopoietic carcinoma cells presenting cell surface ligands for Siglec-7. We affinity-purified the ligands using Fc-ligated recombinant Siglec-7 and diSia-dextran polymer, a strong inhibitor for Siglec-7. We then confirmed the counter-receptor for Siglec-7 as leukosialin (CD43) through mass spectrometry, immunoprecipitation, and proximity labeling. Additionally, we demonstrated that the cytotoxicity of NK cells toward K562 cells was suppressed by overexpression of leukosialin in a Siglec-7-dependent manner. Taken together, our data suggest that leukosialin on K562 is a counter-receptor for Siglec-7 on NK cells and that a cluster of the Sia-containing glycan epitope on leukosialin is key as trans-ligand for unmasking the cis-ligand.

A case of gastric and duodenal mucosa-associated lymphoid tissue lymphoma with multiple gastric cancers: a case report.

BACKGROUND: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is often caused by Helicobacter pylori and has a good prognosis. Rarely, patients with MALT lymphoma may have gastric cancer and have a poor prognosis. CASE PRESENTATION: We herein report a case in which surgical treatment was achieved for a 72-year-old male patient with gastric and duodenal MALT lymphoma coexisting multiple gastric cancers. He underwent upper endoscopy for epigastric discomfort, which revealed mucosal erosion on the posterior wall of the middle body of the stomach, an elevated lesion on the duodenal bulb, and a raised tumor on the antrum of the stomach. He was diagnosed with gastric and duodenal MALT lymphoma with early gastric cancer. One month after H. pylori eradication, a second upper endoscopy revealed no improvement in the gastric or duodenal mucosa, and areas of strong redness with a shallow recess just below the cardia of the stomach. As a result, a diagnosis of gastric and duodenal MALT lymphoma with two gastric cancers was made. Total gastrectomy with proximal duodenum resection using intraoperative upper endoscopy and regional lymph node dissection was performed. Pathologically, gastric and duodenal MALT lymphoma and three gastric cancers were detected. Since one of them was an advanced cancer, he started taking S-1 after his general condition improved. CONCLUSION: For early detection of gastric and duodenal MALT lymphoma or gastric cancer, appropriate upper endoscopy and a biopsy are important. It is necessary to select a suitable treatment, such as H. pylori eradication, endoscopic treatment, surgery, chemotherapy, and irradiation, according to the disease state.

Long-Term Survival After Pelvic Exenteration for Locally Recurrent Rectal Cancer Associated With Crohn's Disease With, Adjuvant Chemotherapy, and Immunosuppressive Therapy.

Crohn's disease (CD) is associated with an increased risk of developing colorectal cancer. In particular, cases in which long-term survival is achieved by patients with local recurrence of CD-associated rectal cancer are rare. We report a case in which curative resection was achieved for a 47-year-old man with long-standing CD and locally recurrent rectal cancer. In this case, the patient obtained a long-term survival without recurrence after surgical resection with adjuvant chemotherapy and immunosuppressive therapy. In the management of inflammatory bowel disease patients with cancer, the management of both cancer and inflammatory bowel disease treatment is important for the long-term prognosis.

Pseudosarcomatous myofibroblastic proliferation of the appendix with an abdominal abscess due to diverticulum perforation: a case report.

BACKGROUND: Pseudosarcomatous myofibroblastic proliferation is a rare proliferative lesion of the submucosal stroma characterized by myofibroblast proliferation and inflammatory cell infiltration, and is mainly reported in the urinary system. CASE PRESENTATION: We report a 65-year-old male who was referred to our emergency room with right-side iliac fossa pain. The pain gradually worsened for approximately 2 months, and rebound tenderness was positive. Blood examination showed severe inflammatory findings, and enhanced computed tomography revealed a heterogeneous contrast-enhancing mass lesion measured to be 55 × 50 mm in size at the lower right abdomen. Based on these results, the patient was diagnosed with appendicitis with an abdominal abscess. As the inflammation was severe, we drained the abscess before performing surgery. Approximately 1 month after the abscess diminished, interval appendectomy was performed. Macroscopic findings of the resected specimen showed a perforated diverticulum of the appendix and a small adjacent nodule measured to be 14 mm in size. Histopathological examination with hematoxylin and eosin staining revealed that the nodule consisted of fibroblast proliferation and inflammatory cell infiltration. Furthermore, immunohistochemical examination showed positive for smooth muscle actin and desmin and negative for S-100, c-kit, and anaplastic lymphoma kinase. Based on these histopathological results, we diagnosed the nodule as an unusual case of a pseudosarcomatous myofibroblastic proliferation associated with perforation of the diverticulum of the appendix. CONCLUSION: Herein, we report a rare case of a pseudosarcomatous myofibroblastic proliferation that occurred in the appendix with diverticulitis.

[Mastectomy Followed by Skin-Transplantation Restored QOL and Enabled Chemotherapy in Two Cases of Locally Advanced Breast Cancer with Uncontrollable Bleeding].

Here, we report 2 cases of locally advanced breast cancer with uncontrollable bleeding treated with mastectomy followed by skin transplantation. The operation restored the QOL and enabled chemotherapy in postoperative periods. Case 1: A woman in her 70s was brought by an ambulance because of heart failure symptoms. She had a huge breast tumor on her left chest wall that bled repeatedly, necessitating frequent blood transfusions. An operation was performed, and chemotherapy was provided until she died of brain metastasis 1 year and 8 months after surgery. Case 2: A woman in her 70s was urgently hospitalized with a lumbar vertebrae bone fracture. She had a huge breast tumor on her right chest wall that bled repeatedly. Blood examination revealed severe anemia. An operation was performed, and chemotherapy was introduced sequentially. She is alive with a good status 2 years and 1 month after surgery.

Laparoscopic Percutaneous Endoscopic Gastrostomy Is Useful for Elderly.

BACKGROUND: In recent years, enteral nutrition has become relatively easy to perform through the penetration of percutaneous endoscopic gastrostomy (PEG). However, there have been reports of complications, such as mispuncture of other organs at the time of performing PEG. Previously, we had constructed a gastrostomy under the laparotomy for difficult PEG cases, and 2 years ago, we introduced laparoscopically assisted PEG. This study aimed to clarify the feasibility and safety of LAPEG for elderly people over 65 years old. METHODS: We evaluated the perioperative outcomes in 7 elderly patients who underwent LAPEG during these 2 years. In these subjects, the safety of LAPEG was evaluated retrospectively based on the surgical outcomes, perioperative complications, and postoperative course using the clinical archives. RESULTS: The subjects' mean age was 81.1 ± 8.03 years. LAPEG was successful in all 7 patients. The median operation time was 38 minutes (range, 31-71 minutes). Intraoperative and postoperative early or late complications from LAPEG were not observed in our cases. Enteral nutrition was commenced 2 days after PEG placement in all cases without complications. CONCLUSION: We summarized the LAPEG cases performed at our institution for the elderly, and have reported its feasibility and safety. The strongest advantage of LAPEG was that it allowed placement of the PEG without any complication under direct observation of the intraperitoneal cavity to confirm the safety of each organ.

[Curative Resection of Locally Advanced Rectal Cancer with Synchronous Liver Metastasis after Long-Term Chemotherapy].

A 60s man was diagnosed with unresectable advanced rectal cancer with synchronous solitary liver metastasis. Chemotherapy was administered and the primary tumor shrank immediately. However, he still demonstrated dorsal extension; therefore, chemotherapy was continued for approximately 1 year. After long-term chemotherapy, the primary tumor was deemed to be resectable because the dorsal extension had decreased. We achieved curative resection by performing a primary tumor and liver resection and he has shown no recurrence without adjuvant chemotherapy. Although the primary tumor was initially diagnosed as unresectable, it is important to consider the potential for curative resection after long-term chemotherapy.

[A Case of Gastrointestinal Perforation in Gastric Cancer during Chemotherapy with Paclitaxel plus Ramucirumab].

A 54-year-old man underwent distal gastrectomy with D2 lymph node dissection in our institution in March 2017 due to the presence of advanced gastric cancer. The pathological diagnosis was signet ring, poorly differentiated, and moderate differentiated adenocarcinoma, which was pT4aN3aM0, pStage Ⅲc and HER2-negative. After surgery, he received adjuvant chemotherapy with S-1, however, he was diagnosed with dissemination and lymph node recurrence in June. Tumor marker, CEA level decreased after the introduction of the next treatment(capecitabine plus cisplatin), however the tumor marker level rose again in September, and the chemotherapy regimen was changed to weekly paclitaxel(PTX). Furthermore, ramucirumab was added to the weekly PTX regime in January 2018, as the tumor marker level rose again. One week after the last ramucirumab administration he visited our hospital with abdominal pain, and emergency surgery was performed after the diagnosis of a gastrointestinal perforation using CT. The surgery revealed dirty fluid and countless dissemination nodes throughout the abdominal cavity, and a small intestinal perforation on a white dissemination node was identified 70 cm proximal to the end of the ileum. We performed small bowel segmental resection and functional end-to-end anastomosis. No complications were observed, and an oral diet was able to be started after surgery; however, he was introduced to the best supportive care(BSC)as his general condition gradually deteriorated.

Rice leaf hydrophobicity and gas films are conferred by a wax synthesis gene (LGF1) and contribute to flood tolerance.

Floods impede gas (O2 and CO2 ) exchange between plants and the environment. A mechanism to enhance plant gas exchange under water comprises gas films on hydrophobic leaves, but the genetic regulation of this mechanism is unknown. We used a rice mutant (dripping wet leaf 7, drp7) which does not retain gas films on leaves, and its wild-type (Kinmaze), in gene discovery for this trait. Gene complementation was tested in transgenic lines. Functional properties of leaves as related to gas film retention and underwater photosynthesis were evaluated. Leaf Gas Film 1 (LGF1) was identified as the gene determining leaf gas films. LGF1 regulates C30 primary alcohol synthesis, which is necessary for abundant epicuticular wax platelets, leaf hydrophobicity and gas films on submerged leaves. This trait enhanced underwater photosynthesis 8.2-fold and contributes to submergence tolerance. Gene function was verified by a complementation test of LGF1 expressed in the drp7 mutant background, which restored C30 primary alcohol synthesis, wax platelet abundance, leaf hydrophobicity, gas film retention, and underwater photosynthesis. The discovery of LGF1 provides an opportunity to better understand variation amongst rice genotypes for gas film retention ability and to target various alleles in breeding for improved submergence tolerance for yield stability in flood-prone areas.