Helicobacter pylori infection in relation to E-cadherin gene promoter polymorphism and hypermethylation in sporadic gastric carcinomas

AIM: To study Helicobacterpylori (H pylori) infection in relation to E-cadherin (E-cad) promoter polymorphism and hypermethylation in GCs. METHODS: Specimens were taken from representative cancerous lesions and adjacent non-cancerous epithelia of 67 resected GCs. H pylori was detected by real-time PCR of the cagA gene from non-neoplastic epithelium. E-cad promoter polymorphism and hypermethylation were determined by restriction fragment length polymorphism analysis and methylation-specific PCR, respectively. Expression of E-cad protein was determined by immunohistochemistry. RESULTS: H pylori was found in 57% of patients with GC. H pylori infection was more frequently found in tumors with the -160C/C genotype than those with the -160C/A and -160A/A genotypes (74% vs 47%, P= 0.02). H pylori infection was associated with E-cad methylation in non neoplastic epithelium; however, no significant difference in H pylori was observed between methylated and unmethylated cancerous lesions. CONCLUSION: Patients with the -160C/C genotype might require H pylori infection to promote the inactivation of CDH1, suggesting that H pylori infection might affect GC in an initial stage because polymorphism is germ line. Mechanism of hypermethylation of CDH1 promoter in GC is complex, and H pylori infection might affect it in an initial stage.     

HIF‐1α triggers long‐lasting glutamate excitotoxicity via system xc− in cerebral ischaemia–reperfusion

Hypoxia‐inducible factor 1α (HIF ‐1α) controls many genes involved in physiological and pathological processes. However, its roles in glutamatergic transmission and excitotoxicity are unclear. Here, we proposed that HIF ‐1α might contribute to glutamate‐mediated excitotoxicity during cerebral ischaemia–reperfusion (CIR ) and investigated its molecular mechanism. We showed that an HIF ‐1α conditional knockout mouse displayed an inhibition in CIR ‐induced elevation of extracellular glutamate and N ‐methyl‐d ‐aspartate receptor (NMDAR ) activation. By gene screening for glutamate transporters in cortical cells, we found that HIF ‐1α mainly regulates the cystine–glutamate transporter (system x_c^?) subunit xCT by directly binding to its promoter; xCT and its function are up‐regulated in the ischaemic brains of rodents and humans, and the effects lasted for several days. Genetic deletion of xCT in cortical cells of mice inhibits either oxygen glucose deprivation/reoxygenation (OGDR ) or CIR ‐mediated glutamate excitotoxicity in vitro and in vivo . Pharmaceutical inhibition of system x_c^? by a clinically approved anti‐cancer drug, sorafenib, improves infarct volume and functional outcome in rodents with CIR and its therapeutic window is at least 3 days. Taken together, these findings reveal that HIF ‐1α plays a role in CIR ‐induced glutamate excitotoxicity via the long‐lasting activation of system x_c^?‐dependent glutamate outflow and suggest that system x_c^? is a promising therapeutic target with an extended therapeutic window in stroke. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Intravascular lymphomatosis mimicking acute disseminated encephalomyelitis: a case report

We describe the clinical, radiologic, and postmortem findings in a 49-year-old woman with intravascular lymphomatosis. The patient presented with progressive limb weakness followed by progressive disseminated cerebral neurologic symptoms. Disseminated encephalomyelitis was suspected due to the clinical and radiologic findings. Steroid pulse therapy and intravenous immunoglobulin were given but did not help. The patient died of multiple organ failure 3 months after the onset of symptoms. A diagnosis of disseminated intravascular large B-cell lymphomatosis was established based on findings from histopathology and immunohistochemistry studies on autopsy specimens of the brain and other visceral organs collected postmortem.     

Angiographic and clinical manifestations of coronary fistulas in Chinese people: 15-year experience

BACKGROUND: Coronary artery fistula (CAF) is an anomaly resulting in the steal phenomenon of coronary blood flow, which may cause morbidity or mortality. CAFs in Chinese patients after long-term follow-up of 15 years were retrospectively analyzed. METHODS AND RESULTS: From September, 1992 to August, 2007, 152 CAFs were detected in 28,210 coronary angiograms from 125 patients. Clinical and angiographic data of all patients were analyzed retrospectively. Two types of CAFs were characterized: type I in 99 patients with 124 solitary coronary to cardiac chamber or great vessel fistula; type II: 26 patients with 28 coronary artery--left ventricular multiple microfistulas. Single-, double-, and triple-CAFs were detected in 79%, 20%, and 1% of patients, respectively. Coexistent coronary lesions were noted in 41% of patients. Fistula-related symptoms included stable angina in 55, myocardial infarction in 2, heart failure in 2, sudden death with ventricular fibrillation in 1, and syncope in 1. Twenty-four patients had coexistent congenital anomalies. Only 9 patients underwent coronary intervention or/and surgery for CAFs. CONCLUSIONS: CAFs may cause trivial or lethal cardiac events, and may coexist with coronary lesion or congenital anomaly. Coronary to cardiac chamber or great vessel fistula and coronary-left ventricular multiple microfistulas have different morphologic and pathological phenomena.     

Value of CT in the diagnosis and management of gallstone ileus

AIM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purpose was to ascertain whether the size of ectopic gallstones would affect treatment strategy. METHODS: Fourteen CT scans in cases of proved gallstone ileus were evaluated retrospectively by two radiologists for the presence or absence of previously reported CT findings to establish the diagnostic criteria. These criteria were applied in a prospective contrast enhanced CT study of 165 patients with acute SBO, which included those 14 cases of gallstone ileus. The hard copy images of 165 CT studies were reviewed by a different group of two radiologists but without previous knowledge of the patient's final diagnosis. All CT data were further analyzed to determine the diagnostic accuracy of gallstone ileus when using CT in prospective evaluation of acute SBO. The size of ectopic gallstone on CT was correlated with the clinical course. RESULTS: The diagnostic criteria of gallstone ileus on CT were established retrospectively, which included: (1) SBO; (2) ectopic gallstone; either rim-calcified or total-calcified; (3) abnormal gall bladder with complete air collection, presence of air-fluid level, or fluid accumulation with irregular wall. Prospectively, CT confirmed the diagnosis in 13 cases of gallstone ileus with these three criteria. Only one false negative case could be identified. The remaining 151 patients are true negative cases and no false positive case could be disclosed. The overall sensitivity, specificity and accuracy of CT in diagnosing gallstone ileus were 93%, 100%; and 99%, respectively. Surgical exploration was performed in 13 patients of gallstone ileus with ectopic stones sized larger than 3 cm. One patient recovered uneventfully following conservative treatment with an ectopic stone sized 2 cm in the long axis. CONCLUSION: Contrast enhanced CT imaging offered crucial evidence not only for the diagnosis of gallstone ileus but also for decision making in management strategy.     

Cardiac Fas-Dependent and Mitochondria-Dependent Apoptotic Pathways in a Transgenic Mouse Model of Huntington’s Disease

Huntington’s disease is an autosomal dominant neurodegenerative disease caused by a CAG repeat expansion in the huntingtin gene. Heart disease is the second leading cause of death in patients with Huntington’s disease. This study was to evaluate whether cardiac Fas-dependent and mitochondria-dependent apoptotic pathways are activated in transgenic mice with Huntington’s disease. Sixteen Huntington’s disease transgenic mice (HD) and sixteen wild-type (WT) littermates were studied at 10.5 weeks of age. The cardiac characteristics, myocardial architecture, and two major apoptotic pathways in the excised left ventricle from mice were measured by histopathological analysis, Western blotting, and TUNEL assays. The whole heart weight and the left ventricular weight decreased significantly in the HD group, as compared to the WT group. Abnormal myocardial architecture, enlarged interstitial spaces, and more cardiac TUNEL-positive cells were observed in the HD group. The key components of Fas-dependent apoptosis (TNF-alpha, TNFR1, Fas ligand, Fas death receptors, FADD, activated caspase-8, and activated caspase-3) and the key components of mitochondria-dependent apoptosis (Bax, Bax-to-Bcl-2 ratio, cytosolic cytochrome c, activated caspase-9, and activated caspase-3) increased significantly in the hearts of the HD group. Cardiac Fas-dependent and mitochondria-dependent apoptotic pathways were activated in transgenic mice with Huntington’s disease, which might provide one of possible mechanisms to explain why patients with Huntington’s disease will develop heart failure.     

Expanding refractory rectus sheath hematoma: a therapeutic dilemma

Rectus sheath hematoma is an uncommon but well-described complication of a tussive paroxysm. It is an accumulation of blood within the sheath of the rectus abdominis secondary to disruption of the epigastric vessels or the rectus muscle and is often misdiagnosed as acute abdomen. Increases in the number of elderly patients and the use of therapeutic anticoagulation may increase the prevalence and severity of rectus sheath hematomas encountered in clinical practice. Expanding rectus sheath hematomas are occasionally refractory to conservative treatment and may require hemostatic intervention. Here, we describe the case of an 87-year-old woman who presented with two separate rectus sheath hematomas that were precipitated by a paroxysm of coughing. Repeated computed tomography showed two separate expanding rectus sheath hematomas, which were not accompanied by obvious contrast extravasation on angiography. Empiric left inferior epigastric artery embolization resulted in rapid hemodynamic stabilization, and the hematomas shrank gradually. Early empiric transcatheter arterial embolization may be appropriate for patients who are poor surgical candidates and have enlarging hematomas that are refractory to conservative treatment.     

Liver X receptors orchestrate osteoblast/osteoclast crosstalk and counteract pathologic bone loss

Osteoporosis is characterized by enhanced differentiation of bone‐resorbing osteoclasts, resulting in a rapid loss of functional trabecular bone. Bone‐forming osteoblasts and osteoblast‐derived osteocytes perform a key role in the regulation of osteoclast development by providing both the pro‐osteoclastogenic cytokine receptor activator of NF‐κB ligand (RANKL) and its natural decoy receptor osteoprotegerin (OPG). By regulating the RANKL/OPG ratio, osteoblasts hence determine the rate of both osteoclast differentiation and bone turnover. Here, we describe a novel role for liver X receptors (LXRs) during the crosstalk of bone‐forming osteoblasts and bone‐resorbing osteoclasts. By using a system of osteoblast/osteoclast cocultures, we identify LXRs as regulator of RANKL expression and the RANKL/OPG ratio in osteoblasts. Activation of LXRs drastically reduced the RANKL/OPG ratio and interfered with osteoblast‐mediated osteoclast differentiation in vitro. During an ovariectomy (OVX)‐induced model of postmenopausal osteoporosis, the application of an LXR agonist shifted the RANKL/OPG ratio in vivo, ameliorated the enhanced osteoclast differentiation, and provided complete protection from OVX‐induced bone loss. These results reveal an unexpected involvement of LXRs in the regulation of bone turnover and highlight a potential role for LXRs as novel targets in the treatment of osteoporosis and related diseases. © 2012 American Society for Bone and Mineral Research.