The tumor suppressor WARTS activates the Omi / HtrA2-dependent pathway of cell death

Drosophila tumor suppressor WARTS (Wts) is an evolutionally conserved serine / threonine kinase and participates in a signaling complex that regulates both proliferation and apoptosis to ensure the proper size and shape of the fly. Human counterparts of this complex have been found to be frequently downregulated or mutated in cancers. WARTS, a human homolog of Wts, is also known as tumor suppressor and mitotic regulator, but its molecular implications in tumorigenesis are still obscure. Here, we show that WARTS binds via its C-terminus to the PDZ domain of a proapoptotic serine protease Omi / HtrA2. Depletion of WARTS inhibited Omi / HtrA2-mediated cell death, whereas overexpression of WARTS promoted this process. Furthermore, WARTS can enhance the protease activity of Omi / HtrA2 both in vivo and in vitro. Activation of Omi / HtrA2-mediated cell death is thus a potential mechanism for the tumor suppressive activity of WARTS.     

Dopamine D<Subscript>2</Subscript> receptor plays a role in memory function: implications of dopamine–acetylcholine interaction in the ventral hippocampus

Rationale The role of the hippocampal dopaminergic system in mnemonic function has not been clarified yet. Objective We previously reported that the dopamine D₂ receptor (D₂R) is involved in the regulation of acethylcholin (ACh) release in the hippocampus. In this study, we further investigated ACh–dopamine (DA) interaction in the hippocampus and its involvement in mnemonic function. Methods For experiment 1, rats fed with Cholin (Ch)-deficient chow were used. We examined the effects of D₂R antagonist, raclopride, on cognitive performance using a passive avoidance task. We further carried out in vivo microdialysis to assess the effect of infusion of D₂R agonist, quinpirole, into the ventral hippocampus on its capacity to release ACh. For experiment 2, rats fed with normal chow were used. The performance of a radial arm maze task was assessed to examine the effects of hippocampal injection of D₂R agonist, quinpirole, on memory impairment induced by scopolamine, a muscarinic ACh antagonist. Results In experiment 1, rats fed with Ch-deficient chow showed impaired performances indicated by prolonged latency on retention trials of a passive avoidance task following the hippocampal injection of D₂R antagonist, and showed reduced capacity to release ACh following the injection of D₂R agonist compared with rats fed with normal chow. In experiment 2, memory impairment induced by the intraperitoneal injection of scopolamine was ameliorated by the injection of D₂R agonist into the ventral hippocampus. Conclusion These results indicate the possible involvement of hippocampal ACh–DA interaction in mnemonic processing.     

A case of giant epidermoid cyst occupying the testis

A case of a giant epidermoid cyst of the testis is presented. A 65-year-old man was incidentally pointed out to have left scrotal painless swelling. Physical examination revealed an over hen-egg sized enlargement of the left scrotal contents. Ultrasonography revealed a 7.5 X 5.5 X 4.0 cm solid tumor with heterogeneous echogenicity. No other abnormal findings were observed including tumor markers. Since preoperative examination did not rule out malignancy, we performed left high orchiectomy. Pathological diagnosis was a epidermoid cyst of the testis with a small portion of atrophic testis. Although the preoperative diagnosis of testicular epidermoid cyst is possible, it may be considerably difficult when a giant epidermoid cyst is occupying the testis.     

Computed tomographic scanning and selective laparoscopy in the diagnosis of blunt bowel injury: a prospective study

BACKGROUND: We prospectively evaluated whether computed tomographic (CT) scanning and selective laparoscopy (LP) for the diagnosis of blunt bowel injury (BBI) could prevent nontherapeutic laparotomy and delayed diagnosis. METHODS: Between April 1994 and May 2002, hemodynamically stable patients suspected of having BBI were enrolled in this study. Patients with hemodynamic instability or solid organ injuries with hemoperitoneum were excluded. All patients underwent a physical examination and contrast CT scanning at admission and once again approximately 12 hours (range, 6-24 hours) after admission. LP was performed under general anesthesia in patients who had local peritoneal signs and indirect CT signs (bowel thickening or isolated intraperitoneal fluid) or in whom abdominal pain or tenderness increased or intraperitoneal fluid increased on the repeat CT scan. The indications for a celiotomy were diffuse peritonitis, pneumoperitoneum on the abdominal CT scan, or bowel perforation visible on LP. RESULTS: During the study period, 399 of 1,074 patients admitted for blunt torso injuries were enrolled in this study. Eleven patients underwent emergency celiotomy and 11 underwent LP immediately after admission to the emergency department. One nontherapeutic laparotomy was performed among the patients who underwent celiotomy. The LPs revealed seven bowel perforations and one mesenteric laceration. After a repeat CT scan, three and seven of the patients underwent laparotomy and LP, respectively. Four bowel perforations were found by LP. The remaining 198 patients were treated conservatively, and no complications related to a delayed BBI diagnosis occurred. CONCLUSION: CT scanning and selective LP can prevent nontherapeutic laparotomy and delayed diagnosis in patients with suspected BBI.     

Septic intramuscular embolism in a neutropenic patient with myelodysplastic syndrome accompanied by asymptomatic septic pulmonary emboli

Septic embolisms are rare disorders which are associated with increased mortality and morbidity. We describe a rare case of septic intramuscular embolism accompanied by asymptomatic pulmonary embolism in a neutropenic patient. Methicillin-sensitive Staphylococcus aureus (S. aureus) was detected and multiple nodules were revealed in both thighs and lung. Although he was treated with sensitive antibiotics to .S. aureus, the symptoms remained unchanged during the neutropenic period. Fever subsided rapidly and his thigh pain disappeared after neutropenia resolved. A prompt diagnosis and optimal therapeutic decisions are critical for the reduction of mortality.     

Subcellular localization of glucose transporter 4 in the hypothalamic arcuate nucleus of ob/ob mice under basal conditions

Glucose transporter (GLUT) 4 plays an important role in insulin-induced glucose uptake in skeletal muscle and white adipose tissue. Although GLUT4 is abundant in the hypothalamus as well as in these peripheral tissues, little is known about the role of GLUT4 in the hypothalamus. In this study, we examined the subcellular localization of GLUT4 and the activation of insulin signaling pathways in the hypothalamic arcuate nucleus of ob/ob mice under basal conditions. The expression of GLUT4 in the arcuate nucleus of ob/ob mice was higher than that in lean mice. Interestingly, GLUT4 on the plasma membrane increased significantly in neurons of the arcuate nucleus of ob/ob mice when compared to that in lean mice. Because serum insulin levels of ob/ob mice were very high, we hypothesized that insulin strongly stimulates GLUT4 translocation in the arcuate nucleus of ob/ob mice. Unexpectedly, tyrosine phosphorylation of IR and insulin receptor substrate-1 (IRS-1) was faint in the hypothalamus of lean and ob/ob mice. In addition, phosphorylation of IRS-1 at Ser307 in the hypothalamus of ob/ob mice was higher when compared to that in lean mice, suggesting that insulin signaling is impaired by phosphorylation of IRS-1 at Ser307 in the hypothalamus of ob/ob mice. However, serine phosphorylation of Akt in the arcuate nucleus of ob/ob mice increased significantly when compared to that in lean mice. Furthermore, the expression of brain-derived neurotrophic factor, an activator of PI3K-Akt pathway in neurons, increased significantly in the ventromedial hypothalamus of ob/ob mice. We discuss the possibility of novel pathways which induce the translocation of GLUT4 in the arcuate nucleus of ob/ob mice.     

Effect of baclofen on emesis and 24-hour esophageal pH in neurologically impaired children with gastroesophageal reflux disease

OBJECTIVES: Gastroesophageal reflux disease (GERD) is difficult to control with medical therapy in neurologically impaired children. The gamma-aminobutyric acid type B receptor agonist baclofen was recently reported to reduce reflux in adult patients with GERD by reducing the incidence of transient lower esophageal sphincter relaxations. The current study was undertaken to investigate the effects of baclofen on GERD in neurologically impaired children. METHODS: Eight neurologically impaired children with GERD between 2 months and 16 years were studied. Baclofen (0.7 mg/kg/day) was administered orally or via nasogastric tube in three divided doses 30 minutes before meals for 7 days. The frequency of emesis on and off baclofen were recorded as a measure of clinical impact. Twenty-four-hour esophageal pH monitoring was conducted before and on the seventh day of the administration of baclofen. RESULTS: The frequency of emesis was significantly decreased (P = 0.03). The total number of acid refluxes was significantly decreased both during the entire 24-hour period (P = 0.01) and during the postprandial period (P = 0.049). The number of acid refluxes longer than 5 minutes was significantly decreased during the 24-hour period (P = 0.02). The percentage total time of esophageal pH <4.0 and esophageal acid clearance time were not significantly different during the 24-hour period or during the postprandial period. No adverse effects were observed, except for a slight reduction in muscle tone in one subject. CONCLUSIONS: In this 1-week trial, repetitive administration of baclofen reduced the frequency of emesis and the total number of acid refluxes in neurologically impaired children with GERD.     

Angioplasty for the intimal dissection of graft artery immediately after blood reflow: a successful case of renal transplantation

A 58-year-old woman, who had been suffering from chronic renal failure on hemodialysis since 1999, underwent living renal transplantation on January 14, 2003. The donor was her husband, and his left kidney was resected by a hand-assisted retroperitoneoscopic technique. Vascular clamps were removed after vascular anastomoses, but the color of two-thirds of the graft back side was dark, and urine excretion was not observed for 1 hour. The intimal dissection of the graft artery developed false lumen that occluded the blood flow to the transplanted kidney. The graft was resected from the recipient, and an angioplasty was performed for the false lumen of the graft artery after the second cold preservation. The graft with repaired artery was re-transplanted, and urine excretion was observed immediately after operation. Total ischemia time was 5 hours. Clinicopathological acute rejection episode and stenosis of graft artery did not occur for 6 months after operation. The intimal dissection of graft artery might occur at the time of catheterization on the perfusion for cold preservation and/or vascular anastomosis.