Relaparotomy pseudoaneurysm repair after distal pancreatectomy with celiac axis resection (DP-CAR): a case report.

A 76-year-old man underwent distal pancreatectomy with celiac axis resection (DP-CAR) after preoperative chemotherapy for pancreatic cancer with celiac artery invasion. Although postoperative pancreatic leakage and ischemia-induced bile fistula developed, the patient's condition remained stable with good drainage. On postoperative Day 47, a pseudoaneurysm developed at the junction of the gastroduodenal artery and proper hepatic artery. However, cannulation of the guidewire was difficult, and relaparotomy pseudoaneurysm repair was performed. On postoperative Day 56, a pseudoaneurysm reappeared at the same site, and relaparotomy was performed again. On postoperative Day 61, CT confirmed the disappearance of the pseudoaneurysm and preservation of the right and left hepatic arteries. The patient was discharged 107 days postoperatively. Interventional radiology (IVR) remains the best technique to achieve hemostasis for pseudoaneurysms. However, this case demonstrates that even when hemostasis by IVR is difficult, relaparotomy pseudoaneurysm repair after DP-CAR may be useful after some postoperative.

Small bowel volvulus with chylous ascites: a case report.

Here, we report a rare case of small bowel volvulus with chylous ascites. A 93-year-old man with a medical history of angina pectoris presented to the emergency department with abdominal pain. Computed tomography revealed a whirl sign of the mesenteric vessels with the axis of the superior mesenteric artery. A diagnosis of small bowel volvulus was made, and emergency surgery was performed. Laparoscopic examination revealed chylous ascites. Due to severe intestinal edema and difficulty in manipulating the forceps, surgery was transferred to a laparotomy. The entire small bowel was twisted 360° counterclockwise, requiring manual untwisting. Examination of the intestinal tract after untwisting revealed no evidence of ischemia or necrosis. However, because a diverticulum was observed on the mesenteric side of the upper jejunum and considering the influence of secondary small bowel volvulus, partial small bowel resection was performed. The patient had a favorable postoperative course.

Extracellular α-synuclein impairs sphingosine 1-phosphate receptor type 3 (S1PR3)-regulated lysosomal delivery of cathepsin D in HeLa cells.

α-Synuclein (α-Syn)-positive intracellular fibrillar protein deposits, known as Lewy bodies, are thought to be involved in the pathogenesis of Parkinson's disease (PD). Although recent lines of evidence suggested that extracellular α-Syn secreted from pathogenic neurons contributes to the propagation of PD pathology, the precise mechanism of action remains unclear. We have reported that extracellular α-Syn caused sphingosine 1-phosphate (S1P) receptor type 1 (S1PR1) uncoupled from Gi and inhibited downstream G-protein signaling in SH-SY5Y cells, although its patho/physiological role remains to be clarified. Here we show that extracellular α-Syn caused S1P receptor type 3 (S1PR3) uncoupled from G protein in HeLa cells. Further studies indicated that α-Syn treatment reduced cathepsin D activity while enhancing the secretion of immature pro-cathepsin D into cell culture medium, suggesting that lysosomal delivery of cathepsin D was disturbed. Actually, extracellular α-Syn attenuated the retrograde trafficking of insulin-like growth factor-II/mannose 6-phosphate (IGF-II/M6P) receptor, which is under the regulation of S1PR3. These findings shed light on the understanding of dissemination of the PD pathology, that is, the mechanism underlying how extracellular α-Syn secreted from pathogenic cells causes lysosomal dysfunction of the neighboring healthy cells, leading to propagation of the disease.

Poorly differentiated adenocarcinoma with signet ring cells of the gallbladder producing a high level of alpha-fetoprotein: A case report.

INTRODUCTION: Alpha-fetoprotein (AFP) can become elevated in hepatocellular carcinoma (HCC), yolk sac tumors and other malignant tumors of various organs. Herein, we present a case of AFP-producing gallbladder carcinoma with signet ring cells successfully treated with laparoscopic whole-layer cholecystectomy. PRESENTATION OF CASE: A 69-year-old woman was found to have increased levels of the tumor marker AFP (16.1 to 1474 ng/mL), and an irregularly shaped mass 22 mm in size in the gallbladder at 5 months follow-up after transcatheter arterial chemoembolization and radiofrequency ablation for HCC in segment 3 of the liver. As no additional metastases were detected, we diagnosed the patient with either AFP-producing gallbladder carcinoma (cT2aN0M0, cStage IIa, UICC 8th) or gallbladder metastasis from HCC. Laparoscopic whole-layer cholecystectomy was performed, and histological examination revealed AFP positive poorly differentiated adenocarcinoma with signet ring cells (pT2bN0cM0, pStage IIb, UICC 8th). AFP levels were remarkably decreased after operation (15 ng/mL), and no residual tumors or distant metastases were observed on contrast enhanced computed tomography (CE-CT), indicating that the tumor was an AFP-producing gallbladder carcinoma rather than metastasis of HCC. DISCUSSION: Due to the similar developmental origin of the liver and gallbladder, gallbladder carcinoma could produce AFP in some cases. Considering that AFP is predominantly synthesized during embryogenesis, the status of cellular differentiation would be associated with the ability to synthesize AFP. CONCLUSION: When no lesions except for in the gallbladder can account for elevated AFP levels, clinicians should consider AFP-producing gallbladder carcinoma.

Liver metastases 2 years after resection of a very-low-risk duodenal gastrointestinal stromal tumor: a case report.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors, but are the most common mesenchymal tumors of the gastrointestinal tract. The risk classification of GISTs is based on the tumor size, mitotic index, tumor site, and presence of tumor rupture. Recurrence in the very-low-risk group is extremely rare. We herein report a case of liver metastases 2 years after resection of a very-low-risk duodenal GIST. CASE PRESENTATION: A 57-year-old woman presented to the hospital for evaluation of melena. Esophagogastroduodenoscopy showed bleeding from the exposed blood vessels at the top of a submucosal tumor approximately 20 mm in size located in the second (descending) part of the duodenum, and the bleeding was controlled with electrocoagulation. A GIST was suspected, and the patient underwent wedge resection of the duodenum. The resected specimen contained a 16- × 12-mm (< 20-mm) white submucosal tumor composed of spindle cells with a mitotic count of 4 per 50 high-power fields, and a histologically negative margin was achieved. Immunochemical analysis revealed positive tumor staining for c-kit protein and alpha-smooth muscle actin and negative staining for CD34, desmin, and S-100 protein. Therefore, the tumor was diagnosed as a very-low-risk duodenal GIST based on the Fletcher classification and modified Fletcher classification (Joensuu classification). The postoperative course was uneventful, and the patient was discharged on postoperative day 11. At the follow-up visit 2 years postoperatively, contrast-enhanced computed tomography revealed liver tumors in S8 and S6 measuring 26 × 24 and 10 × 10 mm, respectively. Both lesions showed peripheral dominant hyperenhancement with hypoenhancement inside, indicating tissue degeneration within the tumors. These imaging findings closely resembled those of the duodenal GIST. Hence, the patient was diagnosed with liver metastases of GIST 2 years postoperatively. She was subsequently started on treatment with 400 mg of imatinib. At the time of this writing (2 months after diagnosis), the patient was clinically well and asymptomatic and was continuing imatinib therapy. CONCLUSIONS: Recurrence of very-low-risk GISTs is extremely rare. Even a small GIST with low mitotic activity can never be considered completely benign, and long-term follow-up is necessary.

Long-term Outcomes of Cataract Surgery in Patients with Retinitis Pigmentosa.

PURPOSE: To investigate the long-term outcomes of cataract surgery in patients with retinitis pigmentosa (RP). DESIGN: Retrospective, observational study. PARTICIPANTS: Sixty-four patients with typical RP (22 men, 42 women; average age, 62.8 ± 10.1 years) who underwent cataract surgery at Kyushu University Hospital between May 2007 and October 2015 and were followed up for ≥3 years after the surgery. METHODS: Differences between presurgery and postsurgery visual function, including best-corrected visual acuity (BCVA) and parameters in the Humphrey field analyzer (HFA) examination using the central 10-2 program, were investigated. The presurgery conditions of the foveal ellipsoid zone (EZ) were classified into 3 grades (grade 1: invisible; grade 2: abnormal; grade 3: normal) based on OCT findings. MAIN OUTCOME MEASURES: BCVA, the retinal sensitivity in the HFA 10-2 test. RESULTS: Cataract surgery was performed in 96 eyes, with an average follow-up period of 5.8 ± 2.4 years. The mean presurgery BCVA was 0.64 ± 0.52 logarithm of the minimum angle of resolution (logMAR), and the final postsurgery BCVA was 0.61 ± 0.67 logMAR (P = 0.57). Significant improvement in the postsurgery BCVA was observed only in eyes with preserved foveal EZ (grade 3) (P < 0.01). In 62 eyes of 45 patients who underwent the HFA 10-2 test, the mean values of deviation, macular sensitivity, and foveal sensitivity at the final visit were significantly decreased compared with preoperative values (P < 0.01), whereas those in grade 3 eyes did not change significantly after the surgery (P = 0.13). CONCLUSIONS: In the long-term course after cataract surgery in patients with RP, many patients experienced vision loss with progression of the disease. The preoperative finding of preserved foveal EZ was associated with a better visual prognosis, suggesting that EZ evaluation is useful for predicting the long-term visual outcome of cataract surgery in patients with RP.

Activation of atypical protein kinase C by sphingosine 1-phosphate revealed by an aPKC-specific activity reporter.

Atypical protein kinase C (aPKC) isozymes are unique in the PKC superfamily in that they are not regulated by the lipid second messenger diacylglycerol, which has led to speculation about whether a different second messenger acutely controls their function. Here, using a genetically encoded reporter that we designed, aPKC-specific C kinase activity reporter (aCKAR), we found that the lipid mediator sphingosine 1-phosphate (S1P) promoted the cellular activity of aPKC. Intracellular S1P directly bound to the purified kinase domain of aPKC and relieved autoinhibitory constraints, thereby activating the kinase. In silico studies identified potential binding sites on the kinase domain, one of which was validated biochemically. In HeLa cells, S1P-dependent activation of aPKC suppressed apoptosis. Together, our findings identify a previously undescribed molecular mechanism of aPKC regulation, a molecular target for S1P in cell survival regulation, and a tool to further explore the biochemical and biological functions of aPKC.

Intravascular Ultrasound and Angioscopy Assessment of Coronary Plaque Components in Chronic Totally Occluded Lesions.

BACKGROUND: The in vivo lesion morphologies and plaque components of coronary chronic total occlusion (CTO) lesions remain unclear.Methods and Results:We investigated 57 consecutive CTO lesions in 57 patients with stable angina pectoris undergoing elective percutaneous coronary intervention with intravascular ultrasound (IVUS) and coronary angioscopy (CAS) examination. All CTO lesions were classified according to the proximal angiographic lumen pattern; tapered-type (T-CTO) and abrupt-type (A-CTO). The differences in the intracoronary images of these lesion types were evaluated according to the location within the CTO segment. A total of 35 lesions (61.4%) were T-CTO. T-CTO lesions had higher frequencies of red thrombi (proximal 71.4%; middle 74.3%; distal 31.4%; P<0.001) and bright-yellow plaques (yellow-grade 2-3) (48.6%; 74.3%; 2.9%; P<0.001) at the proximal or middle than at the distal subsegment; A-CTO lesions showed no significant differences among the 3 sub-segments. At the middle subsegment, T-CTO lesions showed higher frequencies of positive remodeling (51.4% vs. 18.2%, P=0.01) and bright-yellow plaques (74.3% vs. 13.6%, P<0.001) compared with A-CTO lesions. Multivariate analysis identified bright-yellow plaque as an independent predictor (odds ratio, 7.25; 95% confidence interval, 1.25-42.04; P=0.03) of the occurrence of periprocedural myocardial necrosis. CONCLUSIONS: The combination of IVUS and CAS analysis may be useful for identifying lesion morphology and plaque components, which may help clarify the pathogenetic mechanism of CTO lesions.

Essential Role of Sphingosine Kinase 2 in the Regulation of Cargo Contents in the Exosomes from K562 Cells.

Sphingosine 1-phosphate (S1P) is a bioactive phosphorylated product of sphingosine catalyzed by sphingosine kinase (SphK) and implicated in diverse cellular functions including vesicular trafficking. In the present study we have shown the importance of one of the subtypes of SphK, SphK2, in the regulation of cargo content in exosomes released from human myeloid leukemia K562 cells. First, SphK2 has been shown to localize with N-Rh-PE-positive late endosomes in the cells. Next, siRNA-mediated knockdown of Sphk2 but not SphK1 resulted in a reduction of cargo content in purified exosomes. The involvement of SphK2 in this phenomenon was further investigated by pharmacological approaches. When cells were treated with N,N-dimethylsphingosine (DMS), one of the most frequently used inhibitors for SphK, cargo contents in purified exosomes were enhanced unexpectedly. Finally, it has been shown that DMS has a potency to stimulate SphK2 activity depending on the substrate sphingosine- and the inhibitor-doses as estimated by in vitro assay systems using a purified SphK2. These findings suggest that SphK2/S1P signaling plays an important role in the regulation of cargo content in exosomes in K562 cells.

Extracellular α-synuclein drives sphingosine 1-phosphate receptor subtype 1 out of lipid rafts, leading to impaired inhibitory G-protein signaling.

α-Synuclein (α-Syn)-positive intracytoplasmic inclusions, known as Lewy bodies, are thought to be involved in the pathogenesis of Lewy body diseases, such as Parkinson's disease (PD). Although growing evidence suggests that cell-to-cell transmission of α-Syn is associated with the progression of PD and that extracellular α-Syn promotes formation of inclusion bodies, its precise mechanism of action in the extracellular space remains unclear. Here, as indicated by both conventional fractionation techniques and FRET-based protein-protein interaction analysis, we demonstrate that extracellular α-Syn causes expulsion of sphingosine 1-phosphate receptor subtype 1 (S1P1R) from the lipid raft fractions. S1P1R regulates vesicular trafficking, and its expulsion involved α-Syn binding to membrane-surface gangliosides. Consequently, the S1P1R became refractory to S1P stimulation required for activating inhibitory G-protein (Gi) in the plasma membranes. Moreover, the extracellular α-Syn also induced uncoupling of the S1P1R on internal vesicles, resulting in the reduced amount of CD63 molecule (CD63) in the lumen of multivesicular endosomes, together with a decrease in CD63 in the released exosomes from α-Syn-treated cells. Furthermore, cholesterol-depleting agent-induced S1P1R expulsion from the rafts also resulted in S1P1R uncoupling. Taken together, these results suggest that extracellular α-Syn-induced expulsion of S1P1R from lipid rafts promotes the uncoupling of S1P1R from Gi, thereby blocking subsequent Gi signals, such as inhibition of cargo sorting into exosomal vesicles in multivesicular endosomes. These findings help shed additional light on PD pathogenesis.

Paradoxical embolism caused by ovarian vein thrombosis extending to inferior vena cava in a female with uterine myoma.

Deep vein thrombosis occasionally causes paradoxical embolism in patients with a patent foramen ovale (PFO). We report the case of a 42-year-old female who was hospitalized for stroke. Detailed investigations revealed the existence of a PFO, pulmonary embolism, and ovarian vein thrombosis extending to inferior vena cava. She had a uterine myoma to be operated on but no other thrombophilic disorders. Anticoagulation therapy with direct oral anticoagulant successfully reduced the thrombus and prevented the recurrence of paradoxical embolism. .

Extracellular α-synuclein induces sphingosine 1-phosphate receptor subtype 1 uncoupled from inhibitory G-protein leaving ß-arrestin signal intact.

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The presence of α-synuclein (α-Syn)-positive intracytoplasmic inclusions, known as Lewy bodies, is the cytopathological hallmark of PD. Increasing bodies of evidence suggest that cell-to-cell transmission of α-Syn plays a role in the progression of PD. Although extracellular α-Syn is known to cause abnormal cell motility, the precise mechanism remains elusive. Here we show that impairment of platelet-derived growth factor-induced cell motility caused by extracellular α-Syn is mainly attributed to selective inhibition of sphingosine 1-phosphate (S1P) signalling. Treatment of human neuroblastoma cells with recombinant α-Syn caused S1P type 1 (S1P1) receptor-selective uncoupling from inhibitory G-protein (Gi) as determined by both functional and fluorescence resonance energy transfer (FRET)-based structural analyses. By contrast, α-Syn caused little or no effect on S1P2 receptor-mediated signalling. Both wild-type and α-Syn(A53T), a mutant found in familiar PD, caused uncoupling of S1P1 receptor, although α-Syn(A53T) showed stronger potency in uncoupling. Moreover, S1P1 receptor-mediated ß-arrestin signal was unaltered by α-Syn(A53T). These results suggest that exogenous α-Syn modulates S1P1 receptor-mediated signalling from both Gi and ß-arrestin signals into ß-arrestin-biased signal. These findings uncovered a novel function of exogenous α-Syn in the cells.

Impairment of PDGF-induced chemotaxis by extracellular α-synuclein through selective inhibition of Rac1 activation.

Parkinson's disease (PD) is characterized by α-synuclein (α-Syn)-positive intracytoplasmic inclusions, known as Lewy bodies. Although it is known that extracellular α-Syn is detected in the plasma and cerebrospinal fluid, its physiological significance remains unclear. Here, we show that extracellular α-Syn suppresses platelet-derived growth factor (PDGF)-induced chemotaxis in human neuroblastoma SH-SY5Y cells. The inhibitory effect was stronger in the mutant α-Syn(A53T), found in hereditary PD, and the degree of inhibition was time-dependent, presumably because of the oligomerization of α-Syn. PDGF-induced activation of Akt or Erk was not influenced by α-Syn(A53T). Further studies revealed that α-Syn(A53T) inhibited PDGF-induced Rac1 activation, whereas Cdc42 activation remained unaffected, resulting in unbalanced actin filament remodeling. These results shed light on the understanding of pathological as well as physiological functions of extracellular α-Syn in neuronal cells.

Impact of optical coherence tomography- and coronary angioscopy-assessed neointimal tissue characteristics on occurrence of periprocedural myonecrosis in patients with in-stent restenosis.

Several characteristics of neointimal tissues, including neoatherosclerotic progression, have been reported in lesions with in-stent restenosis (ISR). However, the effects of these characteristics on outcomes after percutaneous coronary intervention (PCI) for ISR lesions remain unclear. We assessed the relationships between neointimal tissue characteristics and the occurrence of periprocedural myonecrosis (PMN) after PCI in ISR lesions. We investigated 72 ISR lesions in 72 patients with stable angina pectoris (SAP) who underwent pre- and post-revascularization optical coherence tomography (OCT) and coronary angioscopy (CAS). All lesions were classified as with PMN, defined by an elevated peak high-sensitivity cardiac troponin-T level during the 24-h post-PCI period, and without PMN. PMN was observed in 23 (31.9 %) lesions. PMN lesions had higher frequencies of OCT-derived thin-cap fibroatheroma (26.1 vs. 6.1 %, P = 0.03), CAS-derived intensive yellow neointima (30.4 vs. 10.2 %, P = 0.04), neointima with complex surface (60.9 vs. 28.6 %, P = 0.01), and CAS-derived atheromatous appearance (CAS-AAP), defined as yellow plaque including complex thrombi underneath disrupted neointimal coverage after ballooning (47.8 vs. 16.3 %, P = 0.008) at the most stenotic sites inside stents, compared to lesions without PMN. Multivariate logistic regression analysis identified CAS-AAP (odds ratio: 3.568, 95 % confidence interval: 1.109-11.475, P = 0.033) as an independent predictor of PMN. For ISR lesions in SAP patients, an OCT- and CAS-based assessment of neointimal tissue characteristics might help to predict the occurrence of PMN.

MicroRNA Regulation of Human Breast Cancer Stem Cells.

MicroRNAs (miRNAs) are involved in virtually all biological processes, including stem cell maintenance, differentiation, and development. The dysregulation of miRNAs is associated with many human diseases including cancer. We have identified a set of miRNAs differentially expressed between human breast cancer stem cells (CSCs) and non-tumorigenic cancer cells. In addition, these miRNAs are similarly upregulated or downregulated in normal mammary stem/progenitor cells. In this review, we mainly describe the miRNAs that are dysregulated in human breast CSCs directly isolated from clinical specimens. The miRNAs and their clusters, such as the miR-200 clusters, miR-183 cluster, miR-221-222 cluster, let-7, miR-142 and miR-214, target the genes and pathways important for stem cell maintenance, such as the self-renewal gene BMI1, apoptosis, Wnt signaling, Notch signaling, and epithelial-to-mesenchymal transition. In addition, the current evidence shows that metastatic breast CSCs acquire a phenotype that is different from the CSCs in a primary site. Thus, clarifying the miRNA regulation of the metastatic breast CSCs will further advance our understanding of the roles of human breast CSCs in tumor progression.

In situ modification of cell-culture scaffolds by photocatalytic decomposition of organosilane monolayers.

We demonstrate a novel application of TiO2 photocatalysis for modifying the cell affinity of a scaffold surface in a cell-culture environment. An as-deposited octadecyltrichlorosilane self-assembled monolayer (OTS SAM) on TiO2 was found to be hydrophobic and stably adsorbed serum albumins that blocked subsequent adsorption of other proteins and cells. Upon irradiation of ultraviolet (UV) light, OTS molecules were decomposed and became permissive to the adhesion of PC12 cells via adsorption of an extracellular matrix protein, collagen. Optimal UV dose was 200 J cm(-2) for OTS SAM on TiO2. The amount of collagen adsorption decreased when excessive UV light was irradiated, most likely due to the surface being too hydrophilic to support its adsorption. This UV-induced modification required TiO2 to be present under the SAM and hence is a result of TiO2 photocatalysis. The UV irradiation for surface modification can be performed before cell plating or during cell culture. We also demonstrate that poly(ethylene glycol) SAM can also be patterned with this method, indicating that it is applicable to both hydrophobic and hydrophilic SAMs. This method provides a unique tool for fabricating cell microarrays and studying dynamical properties of living cells.

Sphingosine kinases modulate the secretion of amyloid ß precursor protein from SH-SY5Y neuroblastoma cells: the role of α-synuclein.

Sphingosine kinases (SphK 1&2) are involved in the regulation of cell survival, differentiation and neurotransmitter secretion. Current data suggest potential links between sphingolipid signalling, α-synuclein (ASN) and Alzheimer's disease (AD). Our aim was to investigate the possible role of SphKs and ASN in the regulation of the production and secretion of the amyloid ß precursor protein (APP). We have previously shown that ASN intensified the secretion and toxicity of amyloid ß (Aß) to the point where it caused cell death. Our current results show that APP, the precursor protein for Aß, is also influenced by ASN. The stable overexpression of wtASN in SH-SY5Y cells caused a three-fold, significant increase of the cellular APP level. This suggests that the influence of ASN on Aß metabolism may actually occur at the level of APP protein rather than only through the changes of its cleavage into Aß. To elucidate the mechanisms of APP modulation the cells were exposed to S1P and an SphK inhibitor (SKI). 72 h S1P treatment at 5 µM caused a nearly 50% reduction of the cellular APP signal. S1P also caused a tendency towards higher APP secretion, though the results were insignificant. The inhibition of SphKs decreased medium APP levels in a dose-dependent manner, reaching significance at 5 µM SKI with a correspondingly elevated intracellular level. Thus, it is reasonable to expect that in fact the influence of SphK activity on APP might be pro-secretory. This would also be in agreement with numerous articles on SphK-dependent secretion in the literature. The chronic nature of AD further suggests that subtle alterations in APP metabolism could have the potential to drive important changes in brain condition.

Ongoing activation of sphingosine 1-phosphate receptors mediates maturation of exosomal multivesicular endosomes.

During late endosome maturation, cargo molecules are sorted into intralumenal vesicles (ILVs) of multivesicular endosomes (MVEs), and are either delivered to lysosomes for degradation or fused with the plasma membranes for exosome release. The mechanism underlying formation of exosomal ILVs and cargo sorting into ILVs destined for exosome release is still unclear. Here we show that inhibitory G protein (Gi)-coupled sphingosine 1-phosphate (S1P) receptors regulate exosomal MVE maturation. Gi-coupled S1P receptors on MVEs are constitutively activated through a constant supply of S1P via autocrine activation within organelles. We also found that the continuous activation of Gi-coupled S1P receptors on MVEs is essential for cargo sorting into ILVs destined for exosome release. Our results reveal a mechanism underlying ESCRT-independent maturation of exosomal MVEs.