424 research outputs found
High-speed infrared phase modulators using short helical pitch ferroelectric liquid crystals
A fast phase modulator based on ferroelectric liquid crystal (FLC) is demonstrated and its performances characterized. For uniform alignment and pure phase modulation, we propose a new FLC device configuration using short helical pitch material and homeotropic alignment structure. This device is driven by periodic in-plane electrode stripes implemented on the surface of both cell substrates. As a result, we have obtained large phase modulation ( \u3e 2 pi at lambda=1.55 mu m) and fast response ( \u3c 200 mu sec)
Neuroprotective effects of mild hypoxia in organotypic hippocampal slice cultures
PurposeThe aim of this study was to investigate the potential effects of mild hypoxia in the mature and immature brain.MethodsWe prepared organotypic slice cultures of the hippocampus and used hippocampal tissue cultures at 7 and 14 days in vitro (DIV) to represent the immature and mature brain, respectively. Tissue cultures were exposed to 10% oxygen for 60 minutes. Twenty-four hours after this hypoxic insult, propidium iodide fluorescence images were obtained, and the damaged areas in the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis.ResultsIn the 7-DIV group compared to control tissue, hypoxia-exposed tissue showed decreased damage in two regions (CA1: 5.59%±2.99% vs. 4.80%±1.37%, P=0.900; DG: 33.88%±12.53% vs. 15.98%±2.37%, P=0.166), but this decrease was not statistically significant. In the 14-DIV group, hypoxia-exposed tissue showed decreased damage compared to control tissues; this decrease was not significant in the CA3 (24.51%±6.05% vs. 18.31%±3.28%, P=0.373) or DG (15.72%±3.47% vs. 9.91%±2.11%, P=0.134), but was significant in the CA1 (50.91%±5.90% vs. 32.30%±3.34%, P=0.004).ConclusionAlthough only CA1 tissues cultured for 14 DIV showed significantly less damage after exposure to hypoxia, the other tissues examined in this study showed a tendency towards less damage after hypoxic exposure. Therefore, mild hypoxia might play a protective role in the brain
Refractory Hypertension and Isosexual Pseudoprecocious Puberty Associated with Renin-Secreting Ovarian Steroid Cell Tumor in a Girl
Steroid cell tumor, not otherwise specified (NOS), are rare ovarian tumor, in addition, it is more rare in children. The majority of these tumors produce several steroid hormones, particularly testosterone. Estrogen also secreted by steroid cell tumor, NOS, but it is uncommon. Furthermore, hypertension is an infrequent sign in steroid cell tumor, NOS. An 8.5-yr-old girl with hypertension and frequent vaginal spotting visited at our clinic. On laboratory evaluation, secondary hypertension due to an elevated plasma renin level and isosexual pseudoprecocious puberty was diagnosed. Right solid ovarian mass was detected in radiologic tests. She underwent a right ooporectomy and it revealed renin and progesterone receptor positive steroid cell tumor, NOS. After operation, her blood pressure returned to normal level and vaginal bleeding disappeared. Even though this case is very rare, when hypertension coincides with virilization or feminization, a renin-secreting ovarian steroid cell tumor, NOS, should be considered
The Mechanism Underlying the Antibacterial Activity of Shikonin against Methicillin-Resistant Staphylococcus aureus
Shikonin (SKN), a highly liposoluble naphthoquinone pigment isolated from the roots of Lithospermum erythrorhizon, is known to exert antibacterial, wound-healing, anti-inflammatory, antithrombotic, and antitumor effects. The aim of this study was to examine SKN antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The SKN was analyzed in combination with membrane-permeabilizing agents Tris and Triton X-100, ATPase inhibitors sodium azide and N,N′-dicyclohexylcarbodiimide, and S. aureus-derived peptidoglycan; the effects on MRSA viability were evaluated by the broth microdilution method, time-kill test, and transmission electron microscopy. Addition of membrane-permeabilizing agents or ATPase inhibitors together with a low dose of SKN potentiated SKN anti-MRSA activity, as evidenced by the reduction of MRSA cell density by 75% compared to that observed when SKN was used alone; in contrast, addition of peptidoglycan blocked the antibacterial activity of SKN. The results indicate that the anti-MRSA effect of SKN is associated with its affinity to peptidoglycan, the permeability of the cytoplasmic membrane, and the activity of ATP-binding cassette (ABC) transporters. This study revealed the potential of SKN as an effective natural antibiotic and of its possible use to substantially reduce the use of existing antibiotic may also be important for understanding the mechanism underlying the antibacterial activity of natural compounds
Characteristics of Early Pancreatic Cancer: Comparison between Stage 1A and Stage 1B Pancreatic Cancer in Multicenter Clinical Data Warehouse Study
BACKGROUND: Little is known about the characteristics of early pancreatic cancer. We aimed to identify the characteristics, clues for early detection, and prognostic factors for early pancreatic cancer by analyzing a large number of patients with stage 1 pancreatic cancer.
METHODS: A clinical data warehouse that includes databases of all the medical records of eight academic institutions was used to select and analyze patients with pancreatic cancer that had been diagnosed from January 2010 to May 2023.
RESULTS: In total, 257 stage 1 pancreatic cancer patients were included. There were 134 men (52%), and the average age was 67.2 ± 9.9 years. Compared to patients with stage 1B pancreatic cancer (2-4 cm), patients with stage 1A pancreatic cancer (≤2 cm) had more tumors in the body and tail than in the head (
CONCLUSIONS: IPMN is closely associated with early pancreatic cancer and may provide an opportunity for early detection. The presence of perineural invasion was a crucial prognostic factor for both overall and disease-free survival in patients with stage 1 pancreatic cancer
The Kinase PDK1 Is Essential for B-Cell Receptor Mediated Survival Signaling
Phosphoinositide-dependent kinase 1 (PDK1) plays an important role in integrating the T cell antigen receptor (TCR) and CD28 signals to achieve efficient NF-κB activation. PDK1 is also an important regulator of T cell development, mediating pre-TCR induced proliferation signals. However, the role of PDK1 in B cell antigen receptor (BCR) signaling and B cell development remains largely unknown. In this study we provide genetic evidence supporting the role of PDK1 in B cell survival. We found PDK1 is required for BCR mediated survival in resting B cells, likely through regulation of Foxo activation. PDK1-dependent signaling to NF-κB is not crucial to resting B cell viability. However, PDK1 is necessary for triggering NF-κB during B cell activation and is required for activated B cell survival. Together these studies demonstrate that PDK1 is essential for BCR-induced signal transduction to Foxo and NF-κB and is indispensable for both resting and activated B cell survival
Adenosquamous Carcinoma of Extrahepatic Bile Duct: A Case Report
Most malignant tumors originating from the biliary tract are adenocarcinomas, and adenosqamous carcinoma of Klatskin's tumor is a very rare finding. An 83-yr-old man was admitted to our hospital because of jaundice. The abdominal computed tomography and magnetic resonance cholangiopancreatography revealed wall thickening and luminal stenosis of both the intrahepatic duct confluent portion and the common hepatic duct. These findings were compatible with Klatskin's tumor, Bismuth type III. Considering the patient's old age, palliative combined modality therapy was performed. After percutaneous transhepatic biliary drainage, biopsy was performed via percutaneous transhepatic cholangioscopy. The histopathologic findings showed adenosquamous carcinoma. External radiotherapy and intraluminal brachytherapy through the endobiliary Y-type stent were then done. Nine months after the radiotherapy, the laboratory findings and the abdominal computed tomography revealed biliary obstruction and progressive hepatic metastasis. The combined modality therapy of external radiotherapy, intraluminal brachytherapy and stenting assisted him to live a normal life until he finally experienced biliary obstruction
Severe fever with thrombocytopenia syndrome phlebovirus non-structural protein activates TPL2 signalling pathway for viral immunopathogenesis
Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV), listed in the World Health Organization Prioritized Pathogens, is an emerging phlebovirus with a high fatality . Owing to the lack of therapies and vaccines , there is a pressing need to understand SFTSV pathogenesis. SFSTV non-structural protein (NSs) has been shown to block type I interferon induction and facilitate disease progression . Here, we report that SFTSV-NSs targets the tumour progression locus 2 (TPL2)-A20-binding inhibitor of NF-κB activation 2 (ABIN2)-p105 complex to induce the expression of interleukin-10 (IL-10) for viral pathogenesis. Using a combination of reverse genetics, a TPL2 kinase inhibitor and Tpl2 mice showed that NSs interacted with ABIN2 and promoted TPL2 complex formation and signalling activity, resulting in the marked upregulation of Il10 expression. Whereas SFTSV infection of wild-type mice led to rapid weight loss and death, Tpl2 mice or Il10 mice survived an infection. Furthermore, SFTSV-NSs P A and SFTSV-NSs K R that lost the ability to induce TPL2 signalling and IL-10 production showed drastically reduced pathogenesis. Remarkably, the exogenous administration of recombinant IL-10 effectively rescued the attenuated pathogenic activity of SFTSV-NSs P A, resulting in a lethal infection. Our study demonstrates that SFTSV-NSs targets the TPL2 signalling pathway to induce immune-suppressive IL-10 cytokine production as a means to dampen the host defence and promote viral pathogenesis
Granular cell tumor of the esophagus in an adolescent
Esophageal granular cell tumor (GCT) is a rare neoplasm originating from the Schwann cells of the submucosal neuronal plexus. Histology is the gold standard for its diagnosis. Endoscopic resection or surgical excision should be considered, depending on the potential for malignancy. Here, we report a case of an esophageal GCT in an adolescent. A 12-year-old boy presented with a 1-year history of dysphagia and vomiting. Upper gastrointestinal endoscopic examination and esophagography showed narrowing of the midesophagus, and computed tomography angiography of the thoracic aorta revealed an esophageal or periesophageal mass posterior to the paratracheal segment of the esophagus. The tumor was surgically excised, and based on the pathological findings, esophageal GCT was diagnosed
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