Influence of nuclear interactions in polyethylene range compensators for carbon-ion radiotherapy

Purpose: A recent study revealed that polyethylene (PE) would cause extra carbon-ion attenua- tion per range shift by 0.45%/cm due to compositional differences in nuclear interactions. The present study aims to assess the influence of PE range compensators on tumor dose in carbon-ion radiotherapy.Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles, for each of which the dose and the relative biological effectiveness (RBE) were estimated at a tumor depth in the middle of spread-out Bragg peak. Assuming exponential behavior for attenuation and yield of these components with depth, the PE effect on dose was calculated for clinical carbon- ion beams and was partly tested by experiment. The two-component model was integrated into a treatment-planning system and the PE effect was estimated in two clinical cases.Results: The attenuation per range shift by PE was 0.1%–0.3%/cm in dose and 0.2%–0.4%/cm in RBE-weighted dose, depending on energy and range-modulation width. This translates into reduction of RBE-weighted dose by up to 3% in extreme cases. In the treatment-planning study, however, the effect on RBE-weighted dose to tumor was typically within 1% reduction.Conclusions: The extra attenuation of primary carbon ions in PE was partly compensated by in- creased secondary particles for tumor dose. In practical situations, the PE range compensators would normally cause only marginal errors as compared to intrinsic uncertainties in treatment planning,patient setup, beam delivery, and clinical response

Hyperhomocysteinemia induced by excessive methionine intake promotes rupture of cerebral aneurysms in ovariectomized rats.

BackgroundHyperhomocysteinemia (HHcy) is associated with inflammation and a rise in the expression of matrix metalloproteinase-9 (MMP-9) in the vascular wall. However, the role of HHcy in the growth and rupture of cerebral aneurysms remains unclear.MethodsThirteen-week-old female Sprague-Dawley rats were subject to bilateral ovariectomy and ligation of the right common carotid artery and fed an 8 % high-salt diet to induce cerebral aneurysms. Two weeks later, they underwent ligation of the bilateral posterior renal arteries. They were divided into two groups and methionine (MET) was or was not added to their drinking water. In another set of experiments, the role of folic acid (FA) against cerebral aneurysms was assessed.ResultsDuring a 12-week observation period, subarachnoid hemorrhage due to aneurysm rupture was observed at the anterior communicating artery (AcomA) or the posterior half of the circle of Willis. HHcy induced by excessive MET intake significantly increased the incidence of ruptured aneurysms at 6-8 weeks. At the AcomA of rats treated with MET, we observed the promotion of aneurysmal growth and infiltration by M1 macrophages. Furthermore, the mRNA level of MMP-9, the ratio of MMP-9 to the tissue inhibitor of metalloproteinase-2, and the level of interleukin-6 were higher in these rats. Treatment with FA abolished the effect of MET, suggesting that the inflammatory response and vascular degradation at the AcomA is attributable to HHcy due to excessive MET intake.ConclusionsWe first demonstrate that in hypertensive ovariectomized rats, HHcy induced by excessive MET intake may be associated with the propensity of the aneurysm wall to rupture

Large Magnetic-Field-Induced Strains in Sintered Chromium Tellurides

Sintered samples of Cr3Te4 and Cr2Te3 are found to show large strains accompanied by large volume changes under a magnetic field. In Cr3Te4, volume increases of deltaV/V = 500-1170 ppm by applying a magnetic field of 9 T are observed over the entire temperature range below 350 K. At room temperature, the deltaV/V value exceeds 1000 ppm, which is considerably larger than the maximum values reported for Cr-based magnets thus far and is comparable to the room-temperature value of forced-volume magnetostriction in invar alloys. Cr2Te3 show a large deltaV/V of 680 ppm when applying a magnetic field of 9 T at 200 K. Both samples display particularly large volume increases around the Curie temperature, where they also show negative thermal expansion due to microstructural effects, suggesting that the cooperation between anisotropic lattice deformation associated with the magnetic ordering and microstructural effects is essential for the manifestation of the large magnetic-field-induced volume changes.Comment: 6 pages, 6 figure

Obstructive azoospermia as an unusual complication associated with herniorrhaphy of an omphalocele: a case report

<p>Abstract</p> <p>Introduction</p> <p>Iatrogenic damage to the seminal tract is one of the causes of obstructive azoospermia, which can be an indication for reconstruction surgery. We present a case of obstructive azoospermia as an unusual complication after neonatal herniorrhaphy of an omphalocele.</p> <p>Case presentation</p> <p>A 30-year-old Japanese man was diagnosed with obstructive azoospermia. He had undergone herniorrhaphy of an omphalocele immediately after birth. Reconstruction surgery of both seminal tracts was performed to pursue the possibility of naturally achieved pregnancy. Intra-operative findings demonstrated that both vasa deferentia were interrupted at the internal inguinal rings, although the abdominal end of the right vas leading to the seminal vesicle was found in the abdominal cavity. The discharge from the stump of the testicular end had no sperm, although the right epididymal tubules were dilated with motile sperm. Therefore, we performed right-sided vasovasostomy in the internal inguinal ring and ipsilateral epididymovasostomy simultaneously.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first report describing obstructive azoospermia as an unusual complication of herniorrhaphy of an omphalocele. It is important to pay attention to the existence of seminal tracts in such surgery as well as in inguinal herniorrhaphy.</p

Claw sign predicts first-pass effect in MT

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE. Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE. Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047). Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke

The predictor of LVO with low NIHSS

Background : Intravenous recombinant tissue plasminogen activator (IV rt-PA) and endovascular treatment have been performed for severe large vessel occlusion (LVO) and the results have been reported at high levels of evidence. However, acute treatment for LVO with mild symptom remains controversial. We retrospectively examined prognostic factors for LVO with mild symptoms. Method : We studied retrospectively the patients within 24 h of onset with large vessel occlusion with NIHSS score ≤ 5. Outcomes were evaluated by modified Rankin Scale (mRS) at 90 days, with 0–2 defined as a good outcome and 3–6 as a poor outcome. Clinical characteristics of each case were examined. Result : Participants comprised 76 patients. Of the 76 patients. ICA occlusion showed good outcome in 17 / 19 cases (90%), whereas MCA occlusion showed good outcome in 36 / 54 cases (67%). Among the 14 cases showing positive results for distal intraarterial signal (d-IAS), outcomes were good in 6 cases (43%). On the other hand, the 32 d-IAS-negative cases showed good outcome in 28 cases (88%). Outcomes were thus significantly poorer for d-IAS-positive cases. Conclusion : MCA occlusion is associated with poor prognosis, even with NIHSS score ≤ 5, and d-IAS may provide a predictor

INVOLVEMENT OF NETS IN CEREBRAL AVM

BACKGROUND: Cerebral arteriovenous malformations (cAVMs) represent tangles of abnormal vasculature without intervening capillaries. High-pressure vascular channels due to abnormal arterial and venous shunts can lead to rupture. Multiple pathways are involved in the pathobiology of cAVMs including inflammation and genetic factors such as KRAS mutations. Neutrophil release of nuclear chromatin, known as neutrophil extracellular traps (NETs), plays a multifunctional role in infection, inflammation, thrombosis, intracranial aneurysms, and tumor progression. However, the relationship between NETs and the pathobiology of cAVMs remains unknown. We tested whether NETs play a role in the pathobiology of cAVMs. METHODS: We analyzed samples from patients who had undergone surgery for cAVM and immunohistochemically investigated expression of citrullinated histone H3 (CitH3) as a marker of NETs. CitH3 expression was compared among samples from cAVM patients, epilepsy patients, and normal human brain tissue. Expressions of thrombotic and inflammatory markers were also examined immunohistochemically in samples from cAVM patients. RESULTS: Expression of CitH3 derived from neutrophils was observed intravascularly in all cAVM samples but not other samples. Nidi of AVMs showed migration of many Iba-I-positive cells adjacent to the endothelium and endothelial COX2 expression, accompanied by expression of IL-6 and IL-8 in the endothelium and intravascular neutrophils. Unexpectedly, expression of CitH3 was not necessarily localized to the vascular wall and thrombus. CONCLUSIONS: Our results offer the first evidence of intravascular expression of NETs, which might be associated with vascular inflammation in cAVMs

Large Benign Polyp of the Extrahepatic Bile Duct (Mimicking Bile Duct Cancer)

An 85-year-old woman was admitted because of epigastric pain. The endoscopic examination showed the presence of duodenal ulcer. Abdominal ultrasonography and computed tomography revealed a dilatation of the common bile duct, but no apparent stones were seen in the biliary tract including the gall bladder. In addition, endoscopic retrograde cholangiography showed a filling defect, 20x30 mm in size, in the extrahepatic bile duct. The laboratory data and serum tumor makers were within normal limits. Carcinoma of the extrahepatic bile duct was tentatively made. At operation, an exploration using cholangioscopy and ultrasonography failed to reveal any malignancy. She underwent a local excision of the biliary tumor. Histological examination of the resected specimen showed a benign papillary adenoma. This case is herein reported because of rarity of the disease, which was incidentally found