Safety and effectiveness of SARS-CoV-2 vaccines for patients with intractable hepatobiliary diseases: A multicenter, questionnaire-based, cross-sectional study.

AIM: There are few data regarding the safety and effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with intractable hepatobiliary diseases. We conducted a multicenter, questionnaire-based, cross-sectional study to determine the safety and effectiveness of the SARS-CoV-2 vaccines in Japanese patients with intractable hepatobiliary disease. METHODS: Patients aged ≥18 years with autoimmune hepatitis (AIH), primary biliary cholangitis, primary sclerosing cholangitis, Budd-Chiari syndrome, idiopathic portal hypertension, and extrahepatic portal vein obstruction at each center were consecutively invited to join the study. Participants were asked to complete a questionnaire regarding their characteristics, vaccination status, post-vaccination adverse effects, and SARS-CoV-2 infection. Additionally, liver disease status, treatment regimens, and liver function test values pre- and post-vaccination were collected. RESULTS: The survey was conducted from September 2021 to May 2022, and 528 patients (220 AIH, 251 primary biliary cholangitis, 6 AIH- primary biliary cholangitis/primary sclerosing cholangitis overlap, 39 primary sclerosing cholangitis, 4 Budd-Chiari syndrome, 5 idiopathic portal hypertension, and 3 extrahepatic portal vein obstruction) participated in the study. Post-vaccination adverse effects were comparable to those observed in the general population. Post-vaccination liver injuries classified as grade 1 or higher were observed in 83 cases (16%), whereas grades 2 and 3 were observed in only six cases (1.1%); AIH-like liver injury requiring treatment was not observed. Overall, 12 patients (2.3%) were infected with SARS-CoV-2, and only one patient was infected 6 months after the second vaccination. CONCLUSION: SARS-CoV-2 vaccines demonstrated satisfactory safety and effectiveness in Japanese patients with intractable hepatobiliary diseases.

Cauda Equina Atrophy in Amyotrophic Lateral Sclerosis on Routine Lumbar Magnetic Resonance Imaging.

OBJECTIVE: The aim of the study was to evaluate the cross-sectional area of the cauda equina in amyotrophic lateral sclerosis (ALS) on routine lumbar magnetic resonance imaging and investigate the diagnostic accuracy in comparison with age- and sex-matched non-ALS controls. METHODS: This retrospective study included 15 ALS patients and 15 age- and sex-matched non-ALS controls. Two independent neuroradiologists measured and compared the total cross-sectional area of the cauda equina of ALS patients and the non-ALS controls at the level of the L3 and L4 using axial T2-weighted images. The cutoff value, sensitivity, specificity, and area under the curve were measured. The interobserver reproducibility of the 2 independently obtained measurements was evaluated. RESULTS: The total cross-sectional area of the cauda equina in the ALS group was significantly smaller than that in the non-ALS group (L3: median, 66.73 vs 90.19 mm 2 , P < 0.001; L4: median, 52.9 vs 67.63 mm 2 , P < 0.001). The cutoff values at L3 and L4 were 76.95 and 61.04 mm 2 with a sensitivity and specificity of 1 and 0.87 and 0.8 and 0.87, respectively. The area under the curve at L3 and L4 were high at 0.96 and 0.94, respectively. The interobserver reproducibility was 0.88 at L3 and 0.89 at L4. CONCLUSIONS: The ALS patients showed significant atrophy of the cauda equina compared with non-ALS patients.

Management of portal hypertension based on portal hemodynamics.

Portal hypertension is most commonly caused by chronic liver disease. As liver damage progresses, portal pressure gradually elevates and hemodynamics of the portal system gradually change. In normal liver, venous returns from visceral organs join the portal trunk and flow into the liver (hepatopetal blood flow). As portal pressure increases due to liver damage, congestion of some veins of the visceral organ occurs (blood flow to and from). Finally, the direction of some veins (the left gastric vein in particular) of the visceral organ change (hepatofugal blood flow) and develop as collateral veins (portosystemic shunt) to reduce portal pressure. Therefore, esophagogastric varices serve as drainage veins for the portal venous system to reduce the portal pressure. In chronic liver disease, as intrahepatic vascular resistance is increased (backward flow theory) and collateral veins develop, adequate portal hypertension is required to maintain portal flow into the liver through an increase of blood flow into the portal venous system (forward flow theory). Splanchnic and systemic arterial vasodilatations increase the blood flow into the portal venous system (hyperdynamic state) and lead to portal hypertension and collateral formation. Hyperdynamic state, especially around the spleen, is detected in patients with portal hypertension. The spleen is a regulatory organ that maintains portal flow into the liver. In this review, surgical treatment, interventional radiology, endoscopic treatment, and pharmacotherapy for portal hypertension (esophagogastric varices in particular) are described based on the portal hemodynamics using schema.

Native structure of photosystem II at 1.95 Å resolution viewed by femtosecond X-ray pulses.

Photosynthesis converts light energy into biologically useful chemical energy vital to life on Earth. The initial reaction of photosynthesis takes place in photosystem II (PSII), a 700-kilodalton homodimeric membrane protein complex that catalyses photo-oxidation of water into dioxygen through an S-state cycle of the oxygen evolving complex (OEC). The structure of PSII has been solved by X-ray diffraction (XRD) at 1.9 ångström resolution, which revealed that the OEC is a Mn4CaO5-cluster coordinated by a well defined protein environment. However, extended X-ray absorption fine structure (EXAFS) studies showed that the manganese cations in the OEC are easily reduced by X-ray irradiation, and slight differences were found in the Mn-Mn distances determined by XRD, EXAFS and theoretical studies. Here we report a 'radiation-damage-free' structure of PSII from Thermosynechococcus vulcanus in the S1 state at a resolution of 1.95 ångströms using femtosecond X-ray pulses of the SPring-8 ångström compact free-electron laser (SACLA) and hundreds of large, highly isomorphous PSII crystals. Compared with the structure from XRD, the OEC in the X-ray free electron laser structure has Mn-Mn distances that are shorter by 0.1-0.2 ångströms. The valences of each manganese atom were tentatively assigned as Mn1D(III), Mn2C(IV), Mn3B(IV) and Mn4A(III), based on the average Mn-ligand distances and analysis of the Jahn-Teller axis on Mn(III). One of the oxo-bridged oxygens, O5, has significantly longer distances to Mn than do the other oxo-oxygen atoms, suggesting that O5 is a hydroxide ion instead of a normal oxygen dianion and therefore may serve as one of the substrate oxygen atoms. These findings provide a structural basis for the mechanism of oxygen evolution, and we expect that this structure will provide a blueprint for the design of artificial catalysts for water oxidation.

Convexity Subarachnoid Hemorrhage Accompanied by Hyperacute Ischemic Stroke.

INTRODUCTION AND OBJECTIVES: The clinical characteristics of convexity subarachnoid hemorrhage (cSAH) accompanying hyperacute ischemic stroke are unknown. We aimed to investigate the incidence and clinical characteristics of cSAH with hyperacute ischemic stroke. METHODS: Participants comprised symptomatic ischemic stroke patients with ≤4.5 h from onset to door who also underwent initial MRI ≤4.5 h from onset. We reviewed initial and follow-up MRI during admission to identify cSAH. Retrospective reviews of cSAH incidence and clinical characteristics were performed. RESULTS: We screened 1,249 consecutive symptomatic ischemic stroke patients, including 384 patients (279 males [73%]; median age, 67 years). Of the 384 patients, arterial ischemic stroke was seen in 382 patients, and venous ischemic stroke in 2 patients. Of the hyperacute arterial ischemic stroke, cSAH was identified within 4.5 h of ischemic stroke onset in 2 patients (0.5%) and around 6 days from ischemic stroke onset in 2 patients (0.5%). Of the hyperacute venous ischemic stroke, cSAH was observed in 1 patient on initial MRI. Comparing the clinical characteristics of hyperacute arterial ischemic stroke with and without cSAH, patients with cSAH were more likely to have arterial stenosis or occlusion ipsilateral to the cSAH (100 vs. 47%, p = 0.048), and the ischemic lesion only in the right hemisphere (100 vs. 33%, p = 0.013). In all cases, outcomes were favorable (modified Rankin Scale 0-1 at 3 months from onset). CONCLUSIONS: Convexity SAH was observed in 0.5% of hyperacute ischemic patients within 4.5 h of ischemic stroke onset and in 0.5% around 6 days from ischemic stroke onset.

Massage of the Hepatoduodenal Ligament Recovers Portal Vein Flow Immediately After the Pringle Maneuver in Hepatectomy.

BACKGROUND: The Pringle maneuver is often used in liver surgery to minimize bleeding during liver transection. Many authors have demonstrated that intermittent use of the Pringle maneuver is safe and effective when performed appropriately. However, some studies have reported that the Pringle maneuver is a significant risk factor for portal vein thrombosis. In this study, we evaluated the effectiveness of portal vein flow after the Pringle maneuver and the impact that massaging the hepatoduodenal ligament after the Pringle maneuver has on portal vein flow. MATERIALS AND METHODS: Patients treated with the Pringle maneuver for hepatectomies performed to treat hepatic disease at our hospital between August 2014 and March 2019 were included in the study (N = 101). We divided these patients into two groups, a massage group and nonmassage group. We measured portal vein blood flow with ultrasonography before and after clamping of the hepatoduodenal ligament. We also evaluated laboratory data after the hepatectomy. RESULTS: Portal vein flow was significantly lower after the Pringle maneuver than before clamping of the hepatoduodenal ligament. The portal vein flow after the Pringle maneuver was improved following massage of the hepatoduodenal ligament. After hepatectomy, serum prothrombin time was significantly higher and serum C-reactive protein was significantly lower in the massage group than in the nonmassage group. CONCLUSION: Massaging the hepatoduodenal ligament after the Pringle maneuver is recommended in order to quickly recover portal vein flow during hepatectomy and to improve coagulability.

Novel Characteristic Skull Magnetic Resonance Imaging Features Associated With Meningioma.

OBJECTIVE: Meningioma-related skull magnetic resonance imaging findings other than hyperostosis are not widely recognized. We evaluated the novel findings of the skull adjacent to meningiomas. METHODS: Records from patients with meningiomas located adjacent to the skull on magnetic resonance imaging (n = 32) were included. Three skull findings (intramedullary prominent vessel, intramedullary enhancement, intramedullary T2-hyperintensity) and the widely known hyperostosis were retrospectively visually assessed. The frequency of these 3 findings and the relevance to each other, and their relationships with hyperostosis, size, length adjacent to the skull, and relative signal intensity of the meningioma were examined. RESULTS: The incidence of the three findings was 46.88%, 53.13%, and 62.5%, respectively, and that of hyperostosis was 46.88%. Each association involving the findings was strong, and they were significantly related to the size and length. CONCLUSIONS: Intramedullary prominent vessel, intramedullary enhancement, and intramedullary T2-hyperintensity may be novel characteristic skull findings associated with meningioma.

Serum procalcitonin concentration within 2 days postoperatively accurately predicts outcome after liver resection.

BACKGROUND: Relatively high mortality and morbidity rates are reported after liver resection (LR). However, the early predictors of complications after LR are not clear. This study was performed to clarify the usefulness of procalcitonin (PCT) for the early prediction of complications after elective LR. METHODS: This observational study included 72 consecutive patients who underwent elective LR from December 2015 to March 2017. Patients were categorized into two groups: those with and without postoperative complications (Clavien-Dindo grade ≥II). The values of postoperative inflammatory markers (white blood cell [WBC] count, C-reactive protein [CRP] and PCT) were compared between the two groups. RESULTS: CRP and PCT were significantly higher in patients with than without complications; however, the WBC count showed no difference within 5 days postoperatively. The maximum area under the receiver operating characteristic curves within 2 days after LR using the WBC count, CRP and PCT were 0.608, 0.697 and 0.860, respectively, PCT had the best predictive ability in the early postoperative period. The PCT level peaked within 2 days postoperatively in 61 patients (85%). The maximum PCT level within 2 days postoperatively (PCT1-2) was significantly higher in patients with than without complications (0.52 vs. 0.19 ng/mL, p<0.001). A cutoff PCT1-2 level of 0.35 ng/mL achieved 80% sensitivity and 83% specificity. In patients without complications, there was no difference in PCT1-2 even when the surgical procedure differed (p=0.935). CONCLUSIONS: PCT1-2 is an early predictive marker after LR and can be similarly used regardless of the LR procedure.

Physiological Laterality of Superficial Cerebral Veins on Susceptibility-Weighted Imaging.

OBJECTIVE: The purpose of this study is to evaluate whether laterality of the superficial cerebral veins can be seen on susceptibility-weighted imaging (SWI) in patients with no intracranial lesions that affect venous visualization. METHODS: We retrospectively evaluated 386 patients who underwent brain magnetic resonance imaging including SWI in our institute. Patients with a lesion with the potential to affect venous visualization on SWI were excluded. Two neuroradiologists visually evaluated the findings and scored the visualization of the superficial cerebral veins. RESULTS: Of the 386 patients, 315 (81.6%) showed no obvious laterality on venous visualization, 64 (16.6%) showed left-side dominant laterality, and 7 (1.8%) showed right-side dominant laterality. CONCLUSIONS: Left-side dominant physiological laterality exists in the visualization of the superficial cerebral veins on SWI. Therefore, when recognizing left-side dominant laterality of the superficial cerebral veins on SWI, the radiologist must also consider the possibility of physiological laterality.

Crystal structures of ß-primeverosidase in complex with disaccharide amidine inhibitors.

ß-Primeverosidase (PD) is a disaccharide-specific ß-glycosidase in tea leaves. This enzyme is involved in aroma formation during the manufacturing process of oolong tea and black tea. PD hydrolyzes ß-primeveroside (6-O-ß-d-xylopyranosyl-ß-d-glucopyranoside) at the ß-glycosidic bond of primeverose to aglycone, and releases aromatic alcoholic volatiles of aglycones. PD only accepts primeverose as the glycone substrate, but broadly accepts various aglycones, including 2-phenylethanol, benzyl alcohol, linalool, and geraniol. We determined the crystal structure of PD complexes using highly specific disaccharide amidine inhibitors, N-ß-primeverosylamidines, and revealed the architecture of the active site responsible for substrate specificity. We identified three subsites in the active site: subsite -2 specific for 6-O-ß-d-xylopyranosyl, subsite -1 well conserved among ß-glucosidases and specific for ß-d-glucopyranosyl, and wide subsite +1 for hydrophobic aglycone. Glu-470, Ser-473, and Gln-477 act as the specific hydrogen bond donors for 6-O-ß-d-xylopyranosyl in subsite -2. On the other hand, subsite +1 was a large hydrophobic cavity that accommodates various aromatic aglycones. Compared with aglycone-specific ß-glucosidases of the glycoside hydrolase family 1, PD lacks the Trp crucial for aglycone recognition, and the resultant large cavity accepts aglycone and 6-O-ß-d-xylopyranosyl together. PD recognizes the ß-primeverosides in subsites -1 and -2 by hydrogen bonds, whereas the large subsite +1 loosely accommodates various aglycones. The glycone-specific activity of PD for broad aglycone substrates results in selective and multiple release of temporally stored alcoholic volatile aglycones of ß-primeveroside.

Stenting of Inferior Right Hepatic Vein in a Patient with Budd-Chiari Syndrome: A Case Report.

A Japanese man in his 20s was referred to our hospital with a two-month history of abdominal fullness and leg edema. Abdominal computed tomography revealing massive ascites and ostial blockage of the main hepatic veins, and angiographic evaluation demonstrating obstruction of the main hepatic veins yielded a diagnosis of Budd-Chiari syndrome (BCS). Diuretic agents were prescribed for the ascites but failed to provide relief. The patient was referred to our department for further evaluation and treatment. Angiography showed ostial obstruction of the main hepatic veins, with most of the portal hepatic flow draining from an inferior right hepatic vein (IRHV) into the inferior vena cava (IVC) thorough an intrahepatic portal venous and venovenous shunt. Access between the main hepatic veins and IVC was impossible, but cannulation between the IRHV and IVC was achieved. Because of the venovenous connection between the main hepatic vein and the IRHV, metallic stents were placed into two IRHVs to decrease congestion in the hepatic venous outflow. After stent placement followed by balloon expansion, the gradient pressure between the hepatic vein and IVC improved remarkably. The ascites and lower leg edema improved postoperatively, and long-term stent patency (6 years) was achieved.

Safety and Feasibility of Laparoscopic Liver Resection with the Clamp-Crush Method Using the BiSect.

BACKGROUND: Various energy devices are available for resection of the liver parenchyma during laparoscopic liver resection (LLR). We have historically performed liver resections using the Cavitron Ultrasonic Surgical Aspirator (CUSA). More recently, we have used new bipolar forceps (BiSect; Erbe Elektromedizin GmbH, Tübingen, Germany) to perform clamp-crush dissection with good results. The BiSect is a reusable bipolar forceps with a laparoscopic dissecting forceps tip and both an incision mode and coagulation mode. We evaluated the perioperative clinical course of patients who underwent LLR using the clamp-crush method with the BiSect compared with the CUSA. METHODS: This single-center case control study involved patients with liver metastasis from colorectal cancer who underwent LLR using either the BiSect or CUSA at our hospital from January 2019 to December 2022. We performed the LLR using CUSA from January 2019 to early October 2020. After introduction of the BiSect in late October 2020, we used BiSect for the LLR. Before surgery, the three-dimensional liver was constructed based on computed tomography images, and a preoperative simulation was performed. We evaluated the results of LLR using the BiSect versus the CUSA and assessed the short-term results of LLR. RESULTS: During the study period, we performed partial liver resection using the BiSect in 26 patients and the CUSA in 16 patients. In the BiSect group, the median bleeding volume was 55 mL, the median operation time was 227 minutes, and the median postoperative length of hospital stay was 9 days. In the CUSA group, the median bleeding volume was 87 mL, the median operation time was 305 minutes, and the median postoperative length of hospital stay was 10 days. There were no statistically significant differences in the clinical course including bile leakage, bile duct stenosis, and post operative hospital stay between the two groups. CONCLUSIONS: Compared with LLR using the CUSA, the clamp-crush method using the BiSect in LLR is a safe and useful liver transection technique. Further study should be conducted to clarify whether BiSect is safe and useful in LLR for patients with other tumor types and patients who undergo other procedures.

Clinical features of extrahepatic portal vein obstruction: Myeloproliferative neoplasms eliminate hypersplenic hematologic changes in extrahepatic portal vein obstruction.

Extrahepatic portal vein obstruction (EHPVO) is a rare disease. Most EHPVO patients are usually referred to a gastroenterologist for intestinal bleeding and hypersplenic thrombocytopenia; however, hypercoagulative diseases may be occult in these patients and require anticoagulation. The purpose of this study was to elucidate the clinical characteristics of EHPVO. We conducted a retrospective analysis of the hospital database, evaluating the medical records of 15 patients (7 males, 8 females, mean age of onset 42.0 years, range 5-74 years). Thirteen of 15 EHPVO patients (86.7%) had intestinal varices. These included 10 esophageal (66.7%), 12 gastric (80.0%), and 6 ectopic varices (40.0%). Nine (60.0%) of 15 had a history of intestinal bleeding. Regarding comorbidities, 5 of 15 (33.3%) suffered from vascular diseases, including acute myocardial infarction, cerebral infarction, pulmonary embolism, Budd-Chiari syndrome, and mesenteric vein thrombosis. The former 3 vascular commodities manifested at less than 32 years of age. Four patients (26.7%) with JAK2V617F mutation were diagnosed as myeloproliferative neoplasm (MPN). 72.3% of EHPVO patients without MPN experienced thrombocytopenic state. No EHPVO patients with MPN experienced thrombo-leukocytopenia. The elevation of white blood cell and platelet counts, and decrease of protein S were seen in EHPVO with MPN, compared with EHPVO without MPN. EHPVO is frequently associated with underlying hypercoagulative factors, causing a dilemma between thrombotic complications and portal hypertensive bleeding. Most EHPVO patients experience an evident thrombocytopenic state due to severe hypersplenism; however, hypersplenic hematologic changes are eliminated in EHPVO with MPN. MPN should be suspected in EHPVO patients negative for thrombo-leukocytopenia.

Distribution of Splenic Arterial Flow and Segmental Spleen Volume for Partial Splenic Arterial Embolization.

INTRODUCTION: The spleen is a lymphatic organ that manages immune surveillance of the blood, produces blood cells, and helps filter the blood, remove old blood cells, and fight infection. The normal splenic weight is approximately 65-265 g. This study evaluated spleen volume and segmental volume. METHODS: 121 patients who underwent enhanced CT at our center were analyzed. The spleen was divided into upper, middle, and lower segments according to arterial flow area, and the volume of each segment was measured. Patients were classified into two groups as those with and without liver cirrhosis, and differences in the distribution of the segments in these groups was evaluated. RESULTS: The mean upper, middle, and lower spleen segmental volume ratios were 35.4%, 37.0%, and 27.6%, respectively. In the liver cirrhosis group, the segmental splenic volume ratios for the upper, middle, and lower segments were 34.5%, 38.5%, and 28.0%, respectively, indicating that these ratios remain similar regardless of liver cirrhosis status. CONCLUSION: The present findings on segmental spleen volume are useful for estimating infarction volume in cases of partial splenic arterial embolization.

Development of an online UV-visible microspectrophotometer for a macromolecular crystallography beamline.

Measurement of the UV-visible absorption spectrum is a convenient technique for detecting chemical changes of proteins, and it is therefore useful to combine spectroscopy and diffraction studies. An online microspectrophotometer for the UV-visible region was developed and installed on the macromolecular crystallography beamline, BL38B1, at SPring-8. This spectrophotometer is equipped with a difference dispersive double monochromator, a mercury-xenon lamp as the light source, and a photomultiplier as the detector. The optical path is mostly constructed using mirrors, in order to obtain high brightness in the UV region, and the confocal optics are assembled using a cross-slit diaphragm like an iris to eliminate stray light. This system can measure optical densities up to a maximum of 4.0. To study the effect of radiation damage, preliminary measurements of glucose isomerase and thaumatin crystals were conducted in the UV region. Spectral changes dependent on X-ray dose were observed at around 280 nm, suggesting that structural changes involving Trp or Tyr residues occurred in the protein crystal. In the case of the thaumatin crystal, a broad peak around 400 nm was also generated after X-ray irradiation, suggesting the cleavage of a disulfide bond. Dose-dependent spectral changes were also observed in cryo-solutions alone, and these changes differed with the composition of the cryo-solution. These responses in the UV region are informative regarding the state of the sample; consequently, this device might be useful for X-ray crystallography.

Esophagogastric varix caused by extrahepatic portal vein obstruction with essential thrombocythemia: A case report.

Extrahepatic portal vein obstruction (EHPVO) is a very rare disease-causing portal hypertension. Myeloproliferative neoplasm (MPN) including essential thrombocythemia (ET) is reported as a risk factor for EHPVO due to underlying persistent thrombophilia.A Japanese woman in her 40s was referred to our hospital with a one-month history of gastric variceal bleeding due to EHPVO. Laboratory investigation demonstrated thrombocytosis despite portal hypertension. She had a mutation of clonal marker JAK2V617F with EHPVO, which prompted us to consult a hematologist. Bone marrow biopsy revealed megakaryocyte lineage proliferation, leading to a diagnosis of ET.Esophagogastroduodenoscopy indicated esophagogastric varices (LsF2CbRC2, Lg-cF1RC1). Abdominal Computed Tomography and angiography revealed splenomegaly and portal vein thrombosis with cavernous transformation. These radiologic findings suggested EHPVO.The patient had a history of ruptured esophagogastric varices and required prophylaxis against further variceal bleeding prior to anti-thrombotic therapy for EHPVO with ET. We performed laparoscopic Hassab's operation followed by endoscopic variceal ligation (EVL) and hematological cytoreduction therapy.Laparoscopic Hassab's operation and three bi-monthly EVL improved the esophagogastric varix (LmF0RC0, Lg-f F0RC0) at 6 months after surgery. Platelet count decreased to 60.1 x104 /uL by cytoreduction therapy. She was very healthy at 7 months after surgery.Patients with EHPVO are traditionally referred to the gastroenterologist for abdominal pain, intestinal bleeding, or refractory ascites; however, hypercoagulative disease may be occult in such patients and require the attention of a hematologist. When encountering the patients with splanchnic thrombosis caused by EHPVO, the gastroenterologists should screen for hematological disease, including MPN.

The Role of the Spleen in Portal Hypertension.

As liver disease progresses, intrahepatic vascular resistance increases (backward flow theory of portal hypertension) and collateral veins develop. Adequate portal hypertension is required to maintain portal flow into the liver through an increase in blood flow into the portal venous system (forward flow theory of portal hypertension). The splenic artery resistance index is significantly and selectively elevated in cirrhotic patients. In portal hypertension, a local hyperdynamic state occurs around the spleen. Splenomegaly is associated with a poor prognosis in cirrhosis and is caused by spleen congestion and by enlargement and hyperactivation of splenic lymphoid tissue. Hypersplenism can lead to thrombocytopenia caused by increased sequestering and breakdown of platelets in the spleen. The close relationship between the spleen and liver is reflected in the concept of the hepatosplenic axis. The spleen is a regulatory organ that maintains portal flow into the liver and is the key organ in the forward flow theory of portal hypertension. This review summarizes the literature on the role of the spleen in portal hypertension.

Evaluation of splenic infarction ratio and platelet increase ratio after partial splenic artery embolization.

OBJECTIVE: The spleen is part of the lymphatic system and is one of the least understood organs of the human body. It is involved in the production of blood cells and helps filter the blood, remove old blood cells, and fight infection. Partial splenic artery embolization (PSE) is widely used to treat pancytopenia and portal hypertension. The efficacy of PSE for improving thrombocytopenia has been well demonstrated. In this study, we evaluated the splenic infarction ratio and platelet increase ratio after PSE. METHODS: Forty-five consecutive patients underwent PSE from January 2014 to August 2022. We retrospectively evaluated the splenic infarction volume and ratio after PSE and analyzed the relationship between the splenic infarction ratio and platelet increase ratio after PSE. RESULTS: The platelet increase ratio was correlated with the splenic infarction ratio after PSE. The cutoff value for the splenic infarction ratio with a two-fold platelet increase was 63.0%. CONCLUSION: We suggest performance of PSE in patients with a splenic infarction ratio of 63% to double the expected platelet count.

Causes and Management of Endoscopic Retrograde Cholangiopancreatography-Related Perforation: A Retrospective Study.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is essential for diagnosing and treating biliopancreatic disease. Because ERCP-related perforation can result in death, therapeutic decisions are important. The aim of this study was to determine the cause of ERCP-related perforation and suggest appropriate management. METHODS: Between January 1999 and August 2022, 7,896 ERCPs were performed in our hospital. We experienced 15 cases (0.18%) of ERCP-related perforation and conducted a retrospective review. RESULTS: Of the 15 patients, 6 were female and 9 were male, and the mean age was 77.1 years. According to Stapfer's classification, the 15 cases of ERCP-related perforation comprised 3 type I (duodenum), 3 type II (periampullary), 9 type III (distal bile duct or pancreatic duct), and no type IV cases. Fourteen of 15 (92.6%) were diagnosed during ERCP. The main cause of perforation was scope-induced damage, endoscopic sphincterotomy, and instrumentation penetration in type I, II, and III cases, respectively. Four patients with severe abdominal pain and extraluminal fluid collection underwent emergency surgery for repair and drainage. One type III patient with distal bile duct cancer underwent pancreaticoduodenectomy on day 6. Three type III patients with only retroperitoneal gas on computed tomography (CT) performed immediately after ERCP had no symptoms and needed no additional treatment. Seven of the 15 patents were treated by endoscopic nasobiliary drainage (n=5) or CT-guided drainage (n=2). There were no deaths, and all patients were discharged after treatment. CONCLUSIONS: Early diagnosis and appropriate treatment are important in managing ERCP-related perforation.

Structure and mechanism of oxalate transporter OxlT in an oxalate-degrading bacterium in the gut microbiota.

An oxalate-degrading bacterium in the gut microbiota absorbs food-derived oxalate to use this as a carbon and energy source, thereby reducing the risk of kidney stone formation in host animals. The bacterial oxalate transporter OxlT selectively uptakes oxalate from the gut to bacterial cells with a strict discrimination from other nutrient carboxylates. Here, we present crystal structures of oxalate-bound and ligand-free OxlT in two distinct conformations, occluded and outward-facing states. The ligand-binding pocket contains basic residues that form salt bridges with oxalate while preventing the conformational switch to the occluded state without an acidic substrate. The occluded pocket can accommodate oxalate but not larger dicarboxylates, such as metabolic intermediates. The permeation pathways from the pocket are completely blocked by extensive interdomain interactions, which can be opened solely by a flip of a single side chain neighbouring the substrate. This study shows the structural basis underlying metabolic interactions enabling favourable symbiosis.