Circuit analogy unveiled the haemodynamic effects of the posterior cross vein in the wing vein networks.

We investigated the wing vein network topology in fruit flies and observed that the posterior cross vein (PCV) disrupts the symmetry of the entire network. The fluidic engineering function of this vein's disposition remains unexplored although the wing vein network is known to transport blood. We examined the fluid mechanical effects of the PCV's disposition on this blood-transporting network through numerical simulations involving the removal and rearrangement of the vein, avoiding impractical physical manipulation. We characterised the geometry of each wing membrane cell, a portion of the wing membrane surrounded by a group of veins, by determining the ratio of its surface area to the contact area with the veins. We considered this ratio in association with the flow velocities of seeping water from the blood within the veins to the membrane and evaporating water from the membrane, based on the mass conservation law. We observed that the division of a membrane cell by the PCV maximises the ratio of the areas in the divided cell on the wing-tip side by virtually shifting this vein's connections in our geometric membrane model. We derived blood flow rate and pressure loss within the venous network from their geometry, using an analogy of the venous network with a circuit consisting of hydraulic resistors based on Kirchhoff and Ohm's laws. The overall pressure loss in the network decreased by 20% with the presence of the PCV functioning as a paralleled hydraulic resistor. By contrast, any other cross-vein computationally arranged on another membrane cell as the PCV's substitution did not exhibit a larger reduction in the pressure loss. Overall, our numerical analyses, leveraging geometry and a circuit analogy, highlighted the effects of the PCV's presence and position on the blood-transporting vein network.

Challenges in the diagnosis of the enigmatic primary adrenal leiomyosarcoma: two case reports and review of the literature.

BACKGROUND: Primary adrenal leiomyosarcoma is a rare and aggressive mesenchymal tumor derived from the smooth muscle wall of a central adrenal vein or its tributaries; therefore, tumors tend to invade the inferior vena cava and cause thrombosis. The great majority of tumors grow rapidly, which makes the disease difficult to diagnose in its early clinical stages and needs differentiation from adrenocortical carcinomas for the selection of chemotherapy including mitotane which causes adrenal insufficiency. CASE PRESENTATION: We presented two patients with adrenal leiomyosarcoma who were referred to our hospital with abdominal pain and harboring large adrenal tumors and inferior vena cava thrombosis. The endocrine findings, including serum catecholamine levels, were unremarkable. These two patients were considered clinically inoperable, and CT-guided core needle biopsy was performed to obtain the definitive histopathological diagnosis and determine the modes of therapy. The masses were subsequently diagnosed as primary adrenal leiomyosarcoma based on the histological features and positive immunoreactivity for SMA (smooth muscle actin), desmin, and vimentin. CONCLUSIONS: Adrenal leiomyosarcoma derived from the smooth muscle wall of a central adrenal vein or its tributaries is rare but should be considered a differential diagnosis in the case of nonfunctioning adrenal tumors extending directly to the inferior vena cava. CT-guided biopsy is considered useful for histopathological diagnosis and clinical management of patients with inoperable advanced adrenal tumors without any hormone excess.

Preoperative PI-RADS v2.1 Scoring System Improves Risk Classification in Patients Undergoing Radical Prostatectomy.

BACKGROUND/AIM: The purpose of this study was to examine the prognostic value of Prostate imaging-reporting and data system (PI-RADS) v2.1 scoring system in patients who underwent radical prostatectomy (RP). PATIENTS AND METHODS: Clinical data of 294 patients who received RP between 2006 and 2018 were reviewed and multiple parameters including PI-RADS v2.1 score were employed to identify predictive factors for biochemical recurrence (BCR). Tumor volume was calculated from prostatectomy specimens. RESULTS: Median age at operation and initial PSA level were 67 years old and 7.68 ng/ml, respectively. 44.9 and 24.8% of patients were diagnosed with PI-RADS score 4 and 5 prior to biopsies, respectively. BCR was observed in 17% of patients and median observation period was 63.43 months. After multivariate analysis, PI-RADS v2.1 score 5 [hazard ratio (HR)=2.24, p=0.0124] was an independent predictive factor of BCR in addition to clinical T stage (≥2c) (HR=2.32, p=0.0093) and biopsy Gleason score (≥8) (HR=2.81, p=0.0007). Furthermore, PI-RADS score 5 significantly stratified the prognosis in D'Amico intermediate- and high-risk groups (p=0.0174 and p=0.0013, respectively). We established novel risk classifications including PI-RADS v2.1 score and found that prognostic capabilities were improved as compared to the D'Amico classification. CONCLUSION: The PI-RADS v2.1 score exhibited significant prognostic value in patients with localized prostate cancer following RP. Risk classifications based on PI-RADS v2.1 score might provide better ability for predicting oncological outcomes as compared to the D'Amico classification system.

Endovascular aneurysm repair with mesenteric artery bypass for abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries.

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. Contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm and occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. Aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to a meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and his postoperative course was uneventful. This procedure could be useful and less invasive.

[A Successfully Treated Case of Emergent Hemorrhage from Unresectable Gastric Cancer with Transcatheter Arterial Embolization].

We present the case of a 78-year-old woman who had unresectable advanced gastric cancer that had invaded the pancreas. Her hemoglobin level dropped to 7.0 g/dL during third-line chemotherapy. An upper gastrointestinal endoscopy showed a clot in the stomach, but the bleeding point could not be identified. She received a blood transfusion, but on the third day, she experienced a hemorrhagic shock. We conducted transcatheter arterial embolization(TAE)and subsequently performed embolization of the right gastroepiploic artery and the descending branch of the left gastric artery with an absorbable gelatin sponge. Following TAE, her hemoglobin level stabilized, and she was discharged from the hospital on the ninth day. We resumed chemotherapy, but she died 6.5 months after TAE due to the progression of gastric cancer. Based on this case, we suggest that TAE may be an effective treatment method for bleeding from unresectable advanced gastric cancer.

Prediction of common hepatic artery catheter insertion based on celiac trunk morphology

PURPOSE: This study aimed to predict the ability to insert a 4-5 French (Fr) catheter insertion with a guidewire into the common hepatic artery (CHA) based on celiac trunk morphology. METHODS: This retrospective study included 64 patients who underwent balloon-occluded transcatheter arterial chemoembolization (n = 56), transcatheter arterial chemotherapy (n = 2), or were fitted with an implantable port system (n = 6) between June 2019 and December 2019 in our institution. The morphology of the celiac trunk was classified into three types (upward, horizontal, and downward) based on celiac angiography. The aortic-celiac trunk angle was measured on sagittal images of preprocedural contrast-enhanced computed tomography (CT). We reviewed whether a 4-5-Fr shepherd's hook catheter could advance beyond the CHA using a 0.035-inch guidewire (Radifocus® Guidewire M; Terumo). Three patients were diagnosed with median arcuate ligament syndrome (MALS) based on the characteristic hook shape of the celiac artery on sagittal images of contrast-enhanced CT. The predictive ability of celiac angiography and preprocedural CT for CHA insertion success was evaluated. In unsuccessful cases, the balloon anchor technique (BAT) was attempted as follows: (1) a 2.7/2.8-Fr microballoon catheter (Attendant Delta; Terumo) was placed beyond the proper hepatic artery, and (2) the balloon was inflated as an anchor for parent catheter advancement. RESULTS: Upward, horizontal, and downward celiac trunk types were noted in 42, 9, and 13 patients, respectively. The median CT angle was 122.83° (first quartile-third quartile, 102.88°-136.55°). Insertion in the CHA using the guidewire was successful in 56 of 64 patients (87.50%), and the success rate in the downward type was significantly lower than that in the upward type [42/42 (100%) vs. 7/13 (53.85%), P < 0.001]. The CT angle was significantly larger downward in the unsuccessful group than in the successful group (121.03° vs. 140.70°, P = 0.043). Celiac angiography had a significantly higher area under the curve (AUC) than preprocedural CT (AUC = 0.91 vs. AUC = 0.72, P = 0.040). All three cases of MALS showed unsuccessful CHA insertion. In all eight patients with unsuccessful insertion, the catheter could be advanced using the BAT [8/8 (100%)]. CONCLUSION: Celiac angiography and preprocedural CT could predict CHA catheter insertion using a guidewire, and celiac angiography had high predictability. CT could detect MALS, a risk factor for unsuccessful CHA insertion.

Prophylactic Steroids for Preventing Postembolization Syndrome after Transcatheter Arterial Embolization of Renal Angiomyolipoma: A Comparative Study.

Purpose: Postembolization syndrome (PES) after renal arterial embolization (RAE) can reduce the patient's tolerance of the procedure and extend the length of hospital stay. We aimed to assess the efficacy of steroid administration in preventing PES in patients undergoing RAE for angiomyolipoma (AML). Material and Methods: Between May 2004 and March 2020, 29 RAE procedures in 26 patients with AML were performed. Patient information, including age, sex, tumor size, tuberous sclerosis complex-associated/sporadic AML, hemorrhagic/nonhemorrhagic AML, embolic material, steroid use, medication type, some blood laboratory parameters, hospital stay, and PES occurrence were retrospectively obtained. The prophylactic steroid protocol used in the study was as follows: 250 mg of intravenous methylprednisolone (Solu-Medrol) 2 h before the RAE procedure, followed by 2 days of intravenous prednisolone (Predonine; 2 mg/kg/day), which was tapered by halving the dose every 2 days within the course of 2 weeks. After the discharge, intravenous prednisolone was changed to oral prednisolone (Predonine). PES was defined as the presence of fever, pain, nausea, or vomiting. Data were compared between the steroid and non-steroid groups and between PES and non-PES groups. Results: The PES incidence rate was 76%, and a comparison between the steroid and non-steroid groups revealed that steroid use significantly decreased the incidence of PES (P < 0.001), including fever (P < 0.001), pain (P = 0.005), and nausea (P = 0.028). The use of anti-inflammatory drugs during the hospital stay was significantly lower in the steroid group (P = 0.019). Moreover, in the steroid group, C-reactive protein level was significantly lower (P = 0.006), whereas white blood cell count was significantly higher (P = 0.004). Conversely, the median length of hospital stay was not significantly shorter in the steroid group (P = 0.292). Conclusions: The prophylactic use of steroids before and after embolization of renal AML may be effective in preventing PES in this small retrospective study.

Stent-Graft Placement for Radiation-Induced Abdominal Aortic Stenosis after Renal Autotransplantation.

Renovascular hypertension (RVH) is a common cause of secondary hypertension. However, there have been no reports on RVH due to radiation-induced abdominal aorta stenosis after renal autotransplantation. A 27-year-old woman with a history of neuroblastoma treated by radiation therapy and RVH treated with renal autotransplantation presented with hypertension and dyspnea. At age 19, she had experienced hypertensive heart failure due to RVH from radiation-induced left renal artery stenosis and had undergone renal autotransplantation involving the extraction of her left kidney. Her systolic blood pressure (BP) was well-controlled but had increased progressively. She was diagnosed with hypertensive heart failure and admitted to hospital. Although her dyspnea soon subsided after treatment, her BP remained high. Renal artery ultrasound revealed no obvious stenosis. The ankle brachial pressure index (ABI) showed a significant bilateral decrease to 0.71/0.71 (right/left) from 0.94/0.95 eight years before. Magnetic resonance angiography and aortic angiography revealed severe stenosis in the abdominal aorta, and the systolic pressure gradient of intra-aortic blood flow, distal and proximal to a stenotic lesion, was 58 mmHg. These arterial stenoses in the irradiated area were highly suggestive of radiation-induced vasculopathy. She finally underwent an endovascular VIABAHN VBX balloon-expandable stent-graft placement for this radiation-induced abdominal aorta stenosis, which resolved the pressure gradient. After the procedure, her ABI improved to 0.91/0.88 and her BP was well-controlled. This is the first case of successful stent-graft placement for RVH after renal autotransplantation due to radiation-induced abdominal aorta stenosis as a consequence of neuroblastoma.

Magnetic Resonance Imaging Scan of the Brain After Mild COVID-19 Infection.

PURPOSE: There have been several reports of central nervous system impairments associated with severe coronavirus disease 2019 (COVID-19) infection on head magnetic resonance imaging and angiography (MRI/A). However, head MRI/A is rarely performed in mild cases, and there have been few reports on intracranial changes after COVID-19 infection in these cases. Here, we report a comparative examination of the findings seen in common head MRI/A sequences in mild cases of COVID-19. METHODS: Of the 15,376 patients who underwent head MRI/A examination called "Brain Dock" between June 2020 and June 2021, 746 patients who received a COVID-19 antibody test were evaluated. Positive and negative patients were comparatively examined for head MRI/A findings such as cerebral white matter lesions, ischemic changes, cerebral microbleeds, cerebral aneurysms, arterial stenosis, sinusitis, and other abnormal findings. RESULTS: Overall, 31 (4.2%) patients were COVID-19 positive, and all of them had mild infections not requiring hospitalization. There was no significant difference in patient characteristics and head MRI/A findings between positive and negative patients. All positive patients showed no particular abnormalities in the nasal findings such as olfactory bulb atrophy or thickening of the olfactory mucosa. CONCLUSION: Intracranial lesions in mild patients do not show a clear difference from those in negative patients. This indicates that findings seen in common MRI/A sequences of severe patients are not likely in mild patients, supporting that there is relatively no damage to the central nervous system in mild patients.

Direct TEM Observation of Vacancy-Mediated Heteroatom Incorporation into a Zeolite Framework: Towards Microscopic Design of Zeolite Catalysts.

Incorporating hetero-metal-atom, e.g., titanium, into zeolite frameworks can enhance the catalytic activity and selectivity in oxidation reactions. However, the rational design of zeolites containing titanium at specific sites is difficult because the precise atomic structure during synthesis process remained unclear. Here, a titanosilicate with predictable titanium distribution was synthesized by mediating vacancies in a defective MSE-type zeolite precursor, based on a pre-designed synthetic route including modification of vacancies followed by titanium insertion, where electron microscopy (EM) plays a key role at each step resolving the atomic structure. Point defects including vacancies in the precursor and titanium incorporated into the vacancy-related positions have been directly observed. The results provide insights into the role of point defects in zeolites towards the rational synthesis of zeolites with desired microscopic arrangement of catalytically active sites.

[A Case of Perforation of Unresectable Esophageal Cancer during Nivolumab Therapy].

A 46-year-old man visited our hospital complaining of dysphagia. He was diagnosed with unresectable esophageal cancer with multiple lung metastases(cStage Ⅳb)and gastric cancer(L, Gre, T3N+M0, cStage Ⅲ). The esophageal lesion and the lung metastatic lesions showed shrinkage initially with 5-FU, CDDP(FP)therapy but then re-grew; therefore, the therapy was changed to nivolumab therapy. After three courses of nivolumab therapy, the patient visited our hospital with a high fever. He was admitted as an emergency patient with a diagnosis of esophageal perforation and mediastinal abscess. CT- guided drainage was performed, and a self-expanding metal stent(SEMS)was placed. He was discharged on the 31st day of hospitalization and nivolumab therapy was resumed. We report the first case of esophageal perforation during immunotherapy with nivolumab therapy for esophageal cancer.

Endovascular aneurysm repair with mesenteric artery bypass for an abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries.

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. A contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm, with occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. An aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to the meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and the postoperative course was uneventful. This procedure may be useful and less invasive.

A case of acute appendicitis incarcerated in obturator hernia.

An 85 year-old woman was transferred with a chief complaint of right thigh pain persisting for 5 days. Abdominal contrast-enhanced computed tomography clearly depicted a swollen appendix incarcerated in the right obturator cavity. She underwent an emergent laparoscopic appendectomy and the simultaneous repair of the obturator hernia. At laparoscopy, appendix was found to be incarcerated in the right obturator canal. The incarcerated appendix was successfully flushed out from the sac by spurting saline into the obturator hernia sac through the catheter inserted into the hernia sac. After a laparoscopic appendectomy, the hernia orifice was repaired using the uterine flap. The patient was discharged from the hospital without any sequelae. This report demonstrates a very rare case of obturator hernia incarcerated with appendix. Although patients with obturator hernia incarcerated with small intestine present with the symptoms related to bowel obstruction, patients with incarceration of appendix do not. Moreover, they would show no typical abdominal symptoms associated with acute appendicitis. Therefore, it is important to perform a radiological evaluation promptly to make a definitive diagnosis when a patient with persisting pain of the right thigh or right ileac fossa with a possibility of obturator hernia with incarceration of the appendix is encountered.

Nanoscale-tipped wire array injections transfer DNA directly into brain cells ex vivo and in vivo.

Genetic modification to restore cell functions in the brain can be performed through the delivery of biomolecules in a minimally invasive manner into live neuronal cells within brain tissues. However, conventional nanoscale needles are too short (lengths of ~10 µm) to target neuronal cells in ~1-mm-thick brain tissues because the neuronal cells are located deep within the tissue. Here, we report the use of nanoscale-tipped wire (NTW) arrays with diameters < 100 nm and wire lengths of ~200 µm to address biomolecule delivery issues. The NTW arrays were manufactured by growth of silicon microwire arrays and nanotip formation. This technique uses pinpoint, multiple-cell DNA injections in deep areas of brain tissues, enabling target cells to be marked by fluorescent protein (FP) expression vectors. This technique has potential for use for electrophysiological recordings and biological transfection into neuronal cells. Herein, simply pressing an NTW array delivers and expresses plasmid DNA in multiple-cultured cells and multiple-neuronal cells within a brain slice with reduced cell damage. Additionally, DNA transfection is demonstrated using brain cells ex vivo and in vivo. Moreover, knockdown of a critical clock gene after injecting a short hairpin RNA (shRNA) and a genome-editing vector demonstrates the potential to genetically alter the function of living brain cells, for example, pacemaker cells of the mammalian circadian rhythms. Overall, our NTW array injection technique enables genetic and functional modification of living cells in deep brain tissue areas, both ex vivo and in vivo.

Celiac Artery Dissection and Retroperitoneal Hemorrhage in Median Arcuate Ligament Syndrome Treated With a Stent and Transcatheter Arterial Embolization: Preprocedural 4-Dimensional Computed Tomography Angiography Assessment.

A 61-year-old man presented with retroperitoneal hemorrhage caused by an aneurysm rupture of the pancreaticoduodenal arcade (PDA), and acute celiac artery dissection distal to celiac axis stenosis. Owing to the gradual growth of the false lumen, we planned to deploy a stent to the celiac artery dissection and embolize the PDA aneurysm. Prior to stent placement, we assessed the acute celiac artery dissection distal to the stenosis using four-dimensional computed tomography (CT) angiography through expiration/inspiration/expiration cycle. We diagnosed median arcuate ligament syndrome considering that the celiac axis showed a hooked narrowing at end-expiration, and the compression decreased at end-inspiration. Additionally, the true lumen distal to the stretched axis dilated in the inspiration phase. Therefore, we could advance a catheter into the true lumen during inspiration and successfully deploy a stent. Subsequently, laparoscopic median arcuate ligament release was performed after the stent deployment. A postoperative CT scan showed good patency in the stent, with disappearance of the blood filling the false lumen and with reduced celiac axis stenosis.

Defect Formation, T-Atom Substitution and Adsorption of Guest Molecules in MSE-Type Zeolite Framework-DFT Modeling.

We used computational modeling, based on Density Functional Theory, to help understand the preference for the formation of silanol nests and the substitution of Si by Ti or Al in different crystallographic positions of the MSE-type framework. All these processes were found to be energetically favorable by more than 100 kJ/mol. We suggested an approach for experimental identification of the T atom position in Ti-MCM-68 zeolite via simulation of infrared spectra of pyridine and acetonitrile adsorption at Ti. The modeling of adsorption of hydrogen peroxide at Ti center in the framework has shown that the molecular adsorption was preferred over the dissociative adsorption by 20 to 40 kJ/mol in the presence or absence of neighboring T-atom vacancy, respectively.

Renal Hyperperfusion Injury After Percutaneous Angioplasty for Renovascular Hypertension as a Sequela of Neuroblastoma.

Hyperperfusion injury is a rare but critical complication associated with revascularization for long-standing severe artery stenosis. Here we report a rare case of a patient with renal hyperperfusion injury after undergoing percutaneous transluminal renal angioplasty for renovascular hypertension as a sequela of neuroblastoma after radiation therapy. (Level of Difficulty: Advanced.).

[A Case of Spontaneous Spinal Epidural Hematoma during Chemotherapy with Paclitaxel and Ramucirumab for Advanced Gastric Cancer].

Spontaneous spinal epidural hematomas(SSEH)are rare. The causes of SSEH include hematologic disorders, anticoagulation and antiplatelet therapy, vascular malformations, neoplasms, trauma, or medical interventions, such as epidural catheterization or spinal surgery. However, the cause is usually unclear in most cases. We report a case of SSEH during chemotherapy with paclitaxel and ramucirumab for advanced gastric cancer. A 68-year-old woman was referred to our hospital with a diagnosis of advanced gastric cancer. After 4 courses of neoadjuvant chemotherapy containing S-1 plus oxaliplatin, distal gastrectomy with D2 lymphadenectomy was performed. Postoperative chemotherapy with paclitaxel and ramucirumab was initiated, with a diagnosis of ypStage Ⅲc(T4aN3bM0). She was later transported by ambulance to our hospital with symptoms of sudden onset posterior neck pain and weakness of the extremities. Magnetic resonance imaging(MRI)of her cervical spine showed an epidural hematoma from C2 to C5. The symptoms improved gradually after admission, and the epidural hematoma decreased in size on MRI. Hemorrhagic events such as SSEH should be considered during treatment with angiogenesis inhibitors.

High-Quality Few-Layer Graphene on Single-Crystalline SiC thin Film Grown on Affordable Wafer for Device Applications.

Graphene is promising for next-generation devices. However, one of the primary challenges in realizing these devices is the scalable growth of high-quality few-layer graphene (FLG) on device-type wafers; it is difficult to do so while balancing both quality and affordability. High-quality graphene is grown on expensive SiC bulk crystals, while graphene on SiC thin films grown on Si substrates (GOS) exhibits low quality but affordable cost. We propose a new method for the growth of high-quality FLG on a new template named "hybrid SiC". The hybrid SiC is produced by bonding a SiC bulk crystal with an affordable device-type wafer and subsequently peeling off the SiC bulk crystal to obtain a single-crystalline SiC thin film on the wafer. The quality of FLG on this hybrid SiC is comparable to that of FLG on SiC bulk crystals and much higher than of GOS. FLG on the hybrid SiC exhibited high carrier mobilities, comparable to those on SiC bulk crystals, as anticipated from the linear band dispersions. Transistors using FLG on the hybrid SiC showed the potential to operate in terahertz frequencies. The proposed method is suited for growing high-quality FLG on desired substrates with the aim of realizing graphene-based high-speed devices.