Upregulation of mucosal soluble fas ligand and interferon-gamma may be involved in ulcerogenesis in patients with Helicobacter pylori-positive gastric ulcer

BACKGROUND

Excessive upregulation of gastric epithelial cell apoptosis is speculated to be associated with ulcerogenesis in Helicobacter pylori-positive peptic ulcer disease. H. pylori may have an ulcerogenic effect through induction of gastric epithelial cell apoptosis mediated by infiltrating T cells and their soluble products.

METHODS

The contents of soluble Fas ligand (sFasL) and interferon-gamma (IFN-gamma) in organ cultures and the degree of apoptosis and the expression of apoptosis-related proteins in the gastric epithelium were examined using the mucosal tissues obtained from the antrum and the ulcer site in patients with H. pylori-positive gastric ulcer (GU). The molecular mechanisms of gastric epithelial cell apoptosis induced by sFasL and IFN-gamma were analyzed using epithelial cell lines, MKN 45 and KATO III.

RESULTS

The mucosal tissues of the ulcer site had substantially higher contents of sFasL and IFN-gamma in organ cultures regardless of its healing stage in association with increased numbers of apoptotic cells and enhanced expression of proapoptotic proteins Bak and Bax in the surface foveolar epithelium as compared with the antral tissues in patients with H. pylori-positive GU. The addition of sFasL caused increases in cytotoxic cell death and caspase-3 activation in MKN 45 and KATO III cells in which IFN-gamma treated cells had more prominent effects than untreated cells. The expression of Bak in MKN 45 cells increased when they were treated with IFN-gamma.

CONCLUSIONS

Upregulation of mucosal sFasL and IFN-gamma may be involved in ulcerogenesis in patients with H. pylori-positive GU through induction of gastric epithelial cell apoptosis.

Mutation and association analysis of the interferon regulatory factor 2 gene (IRF2) with atopic dermatitis

Interferon regulatory factor 2 (IRF-2) is a member of a family of transcriptional factors involved in the modulation of cellular responses to interferons (IFNs) and viral infection as well as in the regulation of cell growth and transformation. Irf2 knockout mice show T helper 1 (Th1) cell development defect and spontaneous development of an inflammatory skin disease. To determine if there are any mutations in IRF2 associated with development of atopic dermatitis (AD), we screened for mutations in the 5' flanking and coding regions of IRF2 in AD patients and control subjects by single-strand conformational polymorphism (SSCP) analysis. We found three mutations in the promoter region ([-829C>T, -830C>T], -684C>T, and -467G>A), one silent mutation in exon 9 (921G>A), and a 10-bp deletion in the 3' untranslated region (1739[ATCCC]8>6). Among them, the -467G allele and the haplotype of the -467G, 921A, and 1739(ATCCC)8 alleles were transmitted preferentially to AD-affected children (P = 0.02 and P = 0.007, respectively). Our data suggest that IRF-2 plays some role in the development of AD in the Japanese population.

Clinical features affecting the results of estrogen replacement therapy on bone density in Japanese postmenopausal women

Although estrogen replacement therapy (ERT) has been established as an effective treatment for postmenopausal bone loss, the clinical features which predict the effects of ERT have not been well investigated in Japanese postmenopausal women. We analyzed the role of physical factors influencing the effect of ERT on vertebral bone mineral density (BMD) in 94 Japanese postmenopausal women treated for 2 years or longer. The increase in BMD with ERT is 17.6 +/- 27.6 mg/cm(2)/year (mean +/- SD) during the first 2 years. Rates of BMD change were negatively correlated with the estimated initial BMD, and positively correlated with age and years since menopause, while no correlation was noted with the body mass index by a simple correlation analysis. The relationships between BMD change and estimated initial BMD or age also held in a multiple regression analysis. The estimated initial BMD and age together accounted for 34.4% of the BMD change during ERT. Furthermore, there were very few (2.4%) nonresponders with a negative linear regression slope of BMD in the osteoporosis and osteopenia group, although 32.7% of the normal initial BMD group were nonresponders. These results suggest that the initial BMD and age are potent predictive factors of the ERT effect on BMD change in Japanese postmenopausal women.

Suppressive effects of cyclosporine A on neutrophils and T cells may be related to therapeutic benefits in patients with steroid-resistant ulcerative colitis

An intravenous infusion of cyclosporine A (CsA) shows clinical benefits in patients with steroid-resistant ulcerative colitis (UC). To clarify its mechanisms, we investigated the ability of CsA to inhibit the functions of neutrophils and T cells. The cytotoxic activity by mucosal T cells was analyzed by anti-CD3-triggered cytotoxicity after lamina propria mononuclear cells were cultured with recombinant interleukin (IL)-2. The chemotactic response, the generation of superoxide, and the production of chemokines, IL-8, and macrophage inflammatory protein-1alpha by neutrophils were examined using a multiple-well chamber assay, a chemiluminescence method, and an enzyme-linked immunosorbent assay (ELISA), respectively. Mucosal chemokine activity was determined by an ELISA using the organ culture supernatant of mucosal biopsy tissues. Pretreatment with CsA caused consistent inhibitions of cytotoxic activity by mucosal T cells and chemotactic migration, superoxide generation, and chemokine production by neutrophils mostly in a dose-dependent manner. In patients who received an intravenous infusion of CsA, mucosal chemokine activity decreased after therapy in parallel with decreases in the numbers of neutrophils and mononuclear cells in the biopsy tissues. These results suggest that suppressive effects of CsA on neutrophils and T cells may be related to therapeutic benefits in patients with steroid-resistant UC.

Induction of endothelial nitric-oxide synthase phosphorylation by the raloxifene analog LY117018 is differentially mediated by Akt and extracellular signal-regulated protein kinase in vascular endothelial cells

Raloxifene is a tissue-selective estrogen receptor modulator. The effect of estrogen on cardiovascular disease is mainly dependent on direct actions on the vascular wall involving activation of endothelial nitric oxide synthase (eNOS) via Akt and extracellular signal-regulated protein kinase (ERK) cascades. Although raloxifene is also known to activate eNOS in the vascular endothelium, the molecular mechanism responsible for this effect remains to be elucidated. In studies of both human umbilical vein endothelial cells and simian virus 40-transformed rat lung vascular endothelial cells (TRLECs), the raloxifene analog LY117018 caused acute phosphorylation of eNOS that was unaffected by actinomycin D and was blocked by the pure estrogen receptor antagonist ICI182,780. Activation of Akt by raloxifene reached a plateau at 15-30 min and declined thereafter, a similar time frame to that of Akt activation by 17beta-estradiol. On the other hand, both activation and phosphorylation of ERK by raloxifene showed a biphasic pattern (peaks at 5 min and 1 h), whereas ERK activation and phosphorylation by 17beta-estradiol reached a plateau at 5 min and declined thereafter. A MEK inhibitor, PD98059, had no effect on the raloxifene-induced Akt activity, suggesting an absence of cross-talk between the ERK and Akt cascades. Either exogenous expression of a dominant-negative Akt or pretreatment of TRLECs with PD98059 decreased the raloxifene-induced eNOS phosphorylation. Moreover, raloxifene stimulated the activation of Akt, ERK, and eNOS in Chinese hamster ovary cells expressing estrogen receptor alpha but not Chinese hamster ovary cells expressing estrogen receptor beta. Our findings suggest that raloxifene-induced eNOS phosphorylation is mediated by estrogen receptor alpha via a nongenomic mechanism and is differentially mediated by Akt- and ERK-dependent cascades.

Effect of endotoxin on P-glycoprotein-mediated biliary and renal excretion of rhodamine-123 in rats

The effects of Klebsiella pneumoniae endotoxin on the biliary excretion and renal handling of rhodamine-123 were investigated in rats at different times after intraperitoneal injection (1 mg/kg of body weight). The typical substrates for P glycoprotein, i.e., cyclosporine, colchicine, and erythromycin, inhibited the biliary clearance of rhodamine-123, whereas a substrate for organic cation transporter, cimetidine, did not inhibit clearance, suggesting that rhodamine-123 is transported mainly by P glycoprotein. The biliary, renal, and tubular secretory clearances of rhodamine-123 and the glomerular filtration rate significantly decreased 6 h after injection of endotoxin but returned to control levels by 24 h. These results suggest that endotoxin-induced decreases in P-glycoprotein-mediated biliary excretion and renal handling of rhodamine-123 were probably due to impairment of P-glycoprotein-mediated transport ability. Pretreatment with pentoxifylline (50 mg/kg) significantly inhibited endotoxin-induced increases in tumor necrosis factor alpha (TNF-alpha) levels in plasma, which ameliorated the endotoxin-induced reduction of the biliary excretion of rhodamine-123. It is likely that endotoxin-induced impairment of the transport of rhodamine-123 is caused, in part, by overproduction of TNF-alpha. The effect of endotoxin on the expression of P-glycoprotein mRNA in liver and kidneys of rats was investigated by using a reverse transcriptase PCR. The expression of Mdr1a mRNA in both liver and kidney decreased 6 h after endotoxin injection and returned to control levels after 24 h, whereas the expression of Mdr1b mRNA in liver increased at both times and that in kidney decreased at 24 h. These findings suggest that K. pneumoniae endotoxin dramatically decreases P-glycoprotein-mediated biliary and renal excretion of rhodamine-123 probably by decreasing the expression of Mdr1a, which is likely due to increased plasma TNF-alpha levels.

[Molecular mechanisms of endothelial dysfunction in diabetes mellitus]

Diabetes is a strong risk factor for vascular diseases. Recent studies have shown that disruption of endothelial cell function results in vascular injury. One of causes underlying the endothelial dysfunction in diabetics is hyperglycemia. Many epidemiological studies demonstrated that hyperglycemia increased the incidence of macrovascular diseases. In contrast to the microvascular complications in diabetes, however, the macrovascular complication often develops even in patients with good glycemic control, suggesting that some factors other than hyperglycemia may contribute to it. Insulin resistance is one of possible candidates for that. In fact, it is shown that insulin resistance is an independent risk factor for atherosclerosis. In this article, we reviewed recent hypothesis explaining how hyperglycemia or insulin resistant state caused endothelial dysfunction.

Coronary endothelial dysfunction in the insulin-resistant state is linked to abnormal pteridine metabolism and vascular oxidative stress

OBJECTIVES

We investigated whether abnormal pteridine metabolism is related to coronary endothelial dysfunction in insulin-resistant subjects.

BACKGROUND

Depletion of tetrahydrobiopterin (BH(4)) and elevation of the 7,8-dihydrobiopterin (BH(2)) (activating and inactivating cofactors of nitric oxide synthase [NOS], respectively) contribute to impairment of NO-dependent vasodilation through reduction of NOS activity as well as increased superoxide anion generation in insulin-resistant rats.

METHODS

Thirty-six consecutive nondiabetic, normotensive and nonobese subjects with angiographically normal coronary vessels were studied. Traditional coronary risk factors, plasma pteridine levels, activities of erythrocyte dihydropteridine reductase (DHPR), the recycling enzyme that converts BH(2) to BH(4) and lipid peroxide (LPO) levels were measured and coronary endothelial function was assessed with graded infusions of acetylcholine (ACh).

RESULTS

When we divided patients into tertiles based on insulin sensitivity, we observed stepwise decreases in the maximal ACh-induced vasodilation and plasma BH(4)/7,8-BH(2) ratio, and increases in coronary LPO production as insulin sensitivity decreased. The ACh-induced vasodilation was positively correlated with insulin sensitivity, BH(4)/7,8-BH(2) ratio and DHPR activity. Furthermore, BH(4)/7,8-BH(2) was inversely correlated with DHPR activity and insulin sensitivity. In multiple stepwise regression analysis, BH(4)/BH(2) was independently related to ACh-induced vasodilation and accounted for 39% of the variance. However, no significant correlation existed between other traditional risk factors and BH(4)/7,8-BH(2).

CONCLUSIONS

These results indicate that both abnormal pteridine metabolism and vascular oxidative stress are linked to coronary endothelial dysfunction in the insulin-resistant subjects.

Increased arterial wall stiffness limits flow volume in the lower extremities in type 2 diabetic patients

OBJECTIVE

To document an association between arterial wall stiffness and reduced flow volume in the lower-extremity arteries of diabetic patients.

RESEARCH DESIGN AND METHODS

We recruited 60 consecutive type 2 diabetic patients who had no history or symptoms of peripheral arterial disease (PAD) in the lower extremities and normal ankle/brachial systolic blood pressure index at the time of the study (non-PAD group) and 20 age-matched nondiabetic subjects (control group). We used an automatic device to measure pulse wave velocity (PWV) in the lower extremities as an index of arterial wall stiffness. At the popliteal artery, we evaluated flow volume and the resistive index as an index of arterial resistance to blood flow using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging.

RESULTS

Consistent with previous reports, we confirmed that the non-PAD group had an abnormally higher PWV compared with that of the control group (P < 0.001). To further demonstrate decreased flow volume and abnormal flow pattern at the popliteal artery in patients with a higher degree of arterial wall stiffness, we assigned the 60 non-PAD patients to tertiles based on their levels of PWV. In the highest group, magnetic resonance angiograms of the calf and foot arteries showed decreased intravascular signal intensity, indicating the decreased arterial inflow in those arteries. The highest group was also characterized by the lowest late diastolic and total flow volumes as well as the highest resistive index among the groups. From stepwise multiple regression analysis, PWV and autonomic function were identified as independent determinants for late diastolic flow volume (r(2) = 0.300; P < 0.001).

CONCLUSIONS

Arterial wall stiffness was associated with reduced arterial flow volume in the lower extremities of diabetic patients.

Endotoxin impairs biliary transport of sparfloxacin and its glucuronide in rats

The effect of endotoxin on glucuronidation and hepatobiliary transport of quinolone antimicrobial agents was investigated in rats using sparfloxacin and p-nitrophenyl glucuronide as model drugs. The biliary clearance experiments were performed 24 h after a single intraperitoneal injection of endotoxin (1 mg/kg). Endotoxin significantly delayed the disappearance of sparfloxacin from plasma and increased plasma concentration of its glucuronide after intravenous injection of sparfloxacin (10 mg/kg). Significant decreases in the systemic clearance of sparfloxacin and the biliary clearance of sparfloxacin and the glucuronide were observed. Endotoxin had no effect on in vitro glucuronidation activity using p-nitrophenol as a substrate. When p-nitrophenyl glucuronide (8 mg/kg) was administered in endotoxin-pretreated rats, significant decreases in the systemic clearance, biliary clearance and renal clearance of p-nitrophenyl glucuronide were observed. These findings suggest that endotoxin decreases the biliary excretion of sparfloxacin and its glucuronide probably due to impairment of their hepatobiliary transport systems and renal handling.

Involvement of nuclear transcription factor Sp1 in regulating glucose transporter-1 gene expression during rat trophoblast differentiation

Glucose transporter-1 (GLUT1) is important in placental glucose transport. However, the mechanism of regulation of placental GLUT1 expression remains to be elucidated. We show here that the level of GLUT1 protein in rat choriocarcinoma cells (Rcho-1) decreased during differentiation. To analyze the regulatory mechanism of rat GLUT1 (rGLUT1) gene expression, we transfected rGLUT1 promoter-chloramphenicol acetyltransferase constructs into Rcho-1 cells. Deletion analysis of the rGLUT1 promoter suggested that the region -76/-53 bp was essential for basal transcriptional activity. Electrophoretic mobility shift assays showed that transcription factors Sp1 and Sp3 bound two GC boxes in the region -99/-33 bp of the rGLUT1 promoter. Mutation analysis of the Sp1 binding sites revealed that the promoter-proximal site located between -76 and -53 bp was essential for basal rGLUT1 promoter activity. Furthermore, the decreased level of GLUT1 may result from a decreased level of Sp1 during differentiation. These findings suggest that Sp1 is involved in the regulation of rGLUT1 gene expression during rat trophoblast differentiation.

[A case of craniopharyngioma with chemical meningitis as an initial symptom]

We reported a rare case of craniopharyngioma with chemical meningitis due to spontaneous rupture of the tumor. A 50-year-old woman was admitted with high fever, headache, and nausea. On physical examination, she had nuchal rigidity. The examination of her cerebral spinal fluid(CSF) revealed pleocytosis(mononuclear cell dominant), low value of glucose level and high content of protein. The feature of her CSF findings suggested tuberculosis or fungal meningitis, but bacteriologic culture of the CSF was negative. The CT scan showed an isodensity mass in the suprasellar region and a spotty calcification in the third ventricle. The MRI with gadolinium enhancement suggested that the tumor must be craniopharyngioma and that meningitis was a type of chemical meningitis due to spontaneous rupture of craniopharyngioma. The corticosteroid therapy was rather effective to the symptoms of fever and headache. Then the operation was performed by neurosurgeons, and the diagnosis of craniopharyngioma was pathologically confirmed. Spontaneous rupture of craniopharyngioma rarely occurred and was followed by chemical meningitis. This case was an extremely rare condition that presented with chemical meningitis as an initial symptom.

Pneumatosis cystoides intestinalis treated with hyperbaric oxygen therapy: usefulness of an endoscopic ultrasonic catheter probe for diagnosis

A 67-year-old woman was admitted to our hospital with a complaint of abdominal pain. Barium enema examination and colonoscopy showed numerous round polypoid lesions covered with normal mucosa in the area from the ascending colon to the splenic flexure. Endoscopic ultrasound examination with an ultrasonic catheter probe revealed a strong echo with distal acoustic shadowing in the third layer of the diseased colonic wall, which suggested the presence of gas in the submucosa. The gaseous cysts disappeared completely after hyberbaric oxygen therapy at 2 to 3 atmospheres absolute (60 minutes, twice a day) for 30 consecutive days.

Progesterone inhibits transcriptional activation of human chorionic gonadotropin-alpha gene through protein kinase A pathway in trophoblast cells

The purpose of this study was to analyze the mechanism of transcriptional inhibition of human chorionic gonadotropin-alpha (hCGalpha) gene by progesterone in trophoblast cells. We stably transfected -290 bp hCGalpha promoter-CAT constructs (-290halphaCAT) into Rcho-1 cells and monitored the promoter activities. Differentiation-dependent activation of -290 bp hCGalpha promoter containing a tandem repeat of cAMP response element (CRE) was inhibited by progesterone in a dose-dependent manner. To further analyze the mechanism of the progesterone action, Rcho-1 cells stably transfected with -290halphaCAT were treated with forskolin in the presence of progesterone. Progesterone inhibited forskolin-induced transcriptional activation of hCGalpha gene. Moreover, progesterone inhibited forskolin-induced transcriptional activation of CRE-CRE-tk-CAT. These results suggest that progesterone may inhibit cAMP-induced transcriptional activation of hCGalpha gene through CRE. Although progesterone did not alter the amount of CRE-binding protein (CREB), which is a main transcriptional factor bound to CRE(s) on hCGalpha promoter, progesterone abolished forskolin-induced CREB phosphorylation. In addition, pretreatment with progesterone abolished forskolin-induced activation of nuclear protein kinase A (PKA). In conclusion, progesterone inhibits hCGalpha gene transcription, at least in part, via the CRE region by inhibiting CREB phosphorylation through PKA pathway in trophoblast cells.

Coordinate upregulation of interleukin-8 and growth-related gene product-alpha is present in the colonic mucosa of inflammatory bowel

BACKGROUND

Although ãlpha-chemokines, such as interleukin (IL)-8 and epithelial neutrophil-activating peptide 78, are implicated in the pathogenesis of inflammatory bowel disease (IBD), little information is currently available on the expression and cellular source of growth-related gene product-alpha (GROalpha) and its functional relationship to other ãlpha-chemokines in the intestinal mucosa of patients with IBD.

METHODS

The contents of IL-8 and GROalpha in organ cultures, the expression of IL-8 and GROalpha mRNA, and the modulatory effects of inflammatory mediators on IL-8 and GROalpha-producing cells were examined using colonic mucosal tissues. In vitro stimulatory effects of IL-8 and GROalpha on neutrophils were investigated in terms of chemotactic migration and superoxide anion generation.

RESULTS

The contents of IL-8 and GROalpha in organ cultures were elevated in patients with IBD, especially in those with active ulcerative colitis (UC). Both IL-8 and GROalpha contents increased according to an increase in histological disease activity in patients with UC, but not in those with Crohn disease. In contrast, no significant correlation was found between the contents of these alpha-chemokines and clinical disease activity. In situ hybridization detected increased expression of IL-8 and GROalpha mRNA in macrophages, pericrypt myofibroblasts, and the epithelium of tissue specimens with active lesions of IBD. The secretion of IL-8 and GROalpha from macrophages and myofibroblasts obtained from control patients was upregulated by inflammatory cytokines and bacterial products. The concentrations of recombinant (r)-IL-8, which covered the levels of activity detected in individual organ cultures or cell cultures of fractionated mucosal cells, could induce chemotactic migration and superoxide anion generation in neutrophils in vitro, and r-GROalpha had synergistic effects on r-IL-8-induced neutrophil activation.

CONCLUSIONS

A coordinate upregulation of IL-8 and GROalpha may be involved in the tissue injury in patients with IBD through their stimulatory effects on neutrophils.

Crush and imprint cytology of subependymoma: a case report

BACKGROUND

There are few descriptions of the cytologic features of subependymoma because this neoplasm is rare and most commonly encountered incidentally at autopsy. Here we report a surgical case of subependymoma occurring in the lateral ventricle and provide the first documentation of the crush cytologic features of this tumor.

CASE

A 34-year-old woman was found to have a tumorous lesion in the right lateral ventricle. At surgery, a 2-cm-diameter tumor was detected in the anterior horn. Histologic examination during surgery revealed that the mass was composed of loose,fibrillary networks and clusters of nuclei showing mild pleomorphism. A number of microcystic formations were evident. Histologically, the neoplasm was considered benign--specifically, a subependymoma. Papanicolaou- or Giemsa-stained crush specimens and imprint smears were also prepared. The cytologic morphology was fundamentally the same as the histologic. In the crush specimens, microcystic formations were readily visible. Moreover, details of the cellular morphology were more easily recognized in the cytologic slides than in the frozen sections.

CONCLUSION

Cytologic examination, particularly crush cytology, appears to be useful for the rapid diagnosis of subependymoma during surgery in combination with the examination of frozen histologic sections.

Effects of bezafibrate and simvastatin on plasma lipoproteins in hypercholesterolemia resistant to hormone replacement therapy

OBJECTIVES

Estrogen replacement therapy has favorable effects on serum lipoprotein levels in postmenopausal women with hypercholesterolemia. However, there are some patients who fail to respond to hormone replacement therapy (HRT) to lower the serum cholesterol level. In these cases, a conventional lipid-lowering therapy will be applied in addition to HRT, while the effects of these drugs are not well understood. In this study, we studied the effects of simvastatin and bezafibrate administered in addition to HRT.

METHODS

Patients who were hypercholesterolemic even after HRT were randomly assigned to three treatment groups: HRT only (control group, n=10), HRT+simvastatin (10 mg/day, n=10), or HRT+bezafibrate (400 mg/day, n=10). Serum lipids and lipoprotein levels were measured throughout 12 weeks.

RESULTS

The serum triglyceride levels were decreased by 24+/-28 and 38+/-13% in the HRT+simvastatin and HRT+bezafibrate groups, respectively. HRT+simvastatin decreased the total cholesterol (21+/-10%) and low-density lipoprotein cholesterol (28+/-12%) levels without affecting the high-density lipoprotein cholesterol (HDL-C) level, while HRT+bezafibrate increased the HDL-C level (12+/-11%).

CONCLUSIONS

Treatment with simvastatin or bezafibrate in addition to HRT should be considered in cases of postmenopausal hypercholesterolemia in which HRT alone fails to lower the serum lipoprotein levels.

Endoscopic ablation with cyanoacrylate glue for isolated gastric variceal bleeding

BACKGROUND

Endoscopic ablation with cyanoacrylate glue may achieve gastric variceal obliteration. A prospective evaluation of its therapeutic effects on bleeding gastric varices was conducted, focusing on endoscopic features.

METHODS

Thirty-seven patients with bleeding gastric varices underwent endoscopic ablation with cyanoacrylate.

RESULTS

Patients with localized-type gastric varices (n = 14) had a better clinical course in terms of recurrent bleeding, variceal eradication, and survival than those with diffuse-type gastric varices (n = 23) after endoscopic ablation with cyanoacrylate. These clinical effects were related to the vascular anatomy of the gastric varices as determined by varicography and 3-dimensional CT. Type 1 vascular anatomy (one varicose vessel without noticeable ramifications) was much more common (86%) in localized-type gastric varices, whereas type 2 vascular anatomy (multiple varicose vessels with complex connecting ramifications) was found almost exclusively (91%) in diffuse-type gastric varices.

CONCLUSIONS

Endoscopic ablation with cyanoacrylate is an effective and safe procedure for patients with bleeding gastric varices. Determination of variceal anatomy may be useful for improving treatment strategies for such patients.

Insulin production in a neuroectodermal tumor that expresses islet factor-1, but not pancreatic-duodenal homeobox 1

We studied a 60-yr-old female with a brain tumor who showed severe symptoms of hypoglycemia (plasma glucose, 2.2 mmol/L) and hyperinsulinemia (1.28 nmol/L) after radiotherapy. The cystic brain tumor contained proinsulin and insulin at concentrations of 13.6 and 1.22 nmol/L, respectively. Immunohistochemical studies showed the tumor cells were ectodermal in origin but not endodermal, based on three diagnostic features of neuroectodermal tumors 1) pseudorosette formation noted under light microscopy, 2) finding of a small number of dense core neurosecretory granules on electron microscopy, and 3) positive immunostaining for both neuronal specific enolase and protein gene product 9.5. These cells also expressed the transcription factor, neurogenin-3, NeuroD/beta 2, and islet factor I, which are believed to be transcription factors in neuroectoderm as well as in pancreatic islet cells, but not pancreatic-duodenal homeobox 1, Pax4, or Nkx2.2. In addition, they did not express glucagon, somatostatin, or glucagon-like peptide-1. Our results show the presence of proinsulin in an ectoderm cell brain tumor that does not express the homeobox gene, pancreatic-duodenal homeobox 1, but expresses other transcription factors, i.e. neurogenin3, NeuroD/beta 2, and islet factor-1, which are related to insulin gene expression in the brain tumor.

Protein-tyrosine phosphatase-1B negatively regulates insulin signaling in l6 myocytes and Fao hepatoma cells

Insulin signaling is regulated by tyrosine phosphorylation of the signaling molecules, such as the insulin receptor and insulin receptor substrates (IRSs). Therefore, the balance between protein-tyrosine kinases and protein-tyrosine phosphatase activities is thought to be important in the modulation of insulin signaling in insulin-resistant states. We thus employed the adenovirus-mediated gene transfer technique, and we analyzed the effect of overexpression of a wild-type protein-tyrosine phosphatase-1B (PTP1B) on insulin signaling in both L6 myocytes and Fao cells. In both cells, PTP1B overexpression blocked insulin-stimulated tyrosine phosphorylation of the insulin receptor and IRS-1 by more than 70% and resulted in a significant inhibition of the association between IRS-1 and the p85 subunit of phosphatidylinositol 3-kinase and Akt phosphorylation as well as mitogen-activated protein kinase phosphorylation. Moreover, insulin-stimulated glycogen synthesis was also inhibited by PTP1B overexpression in both cells. These effects were specific for insulin signaling, because platelet-derived growth factor (PDGF)-stimulated PDGF receptor tyrosine phosphorylation and Akt phosphorylation were not inhibited by PTP1B overexpression. The present findings demonstrate that PTP1B negatively regulates insulin signaling in L6 and Fao cells, suggesting that PTP1B plays an important role in insulin resistance in muscle and liver.

Helicobacter pylori-associated gastric ulcer exhibits enhanced mucosal chemokine activity at the ulcer site

BACKGROUND AND AIM

Although mucosal alpha- and beta-chemokines are considered to be involved in the pathogenesis of Helicobacter pylori-associated gastritis, little is known how these chemokines are related to the ulcerogenesis in peptic ulcer patients. We examined the levels of interleukin (IL)-8 and macrophage inflammatory protein-1alpha (MIP-1alpha) in organ cultures and the numbers of inflammatory cells infiltrating the lamina propria by using the mucosal tissues obtained from gastric ulcer (GU) patients with and without H. pylori infection.

METHODS

Levels of IL-8 and MIP-1alpha secreted in organ cultures were measured by an enzyme-linked immunosorbent assay. Numbers of myeloperoxidase-positive neutrophils, CD68-positive macrophages, and mononuclear cells were determined in tissue sections.

RESULTS

The mucosal tissues of both the gastric antrum and the ulcer site obtained from patients with H. pylori-positive GU showed significantly higher levels of IL-8 and MIP-1alpha and increased numbers of inflammatory cells compared with the corresponding mucosal tissues from those with H. pylori-negative GU or the antral mucosal tissues from H. pylori-negative controls. When the values were compared between the mucosal tissues from the gastric antrum and those from the ulcer site, the latter group of tissues showed significantly higher levels of IL-8 and MIP-1alpha and increased numbers of neutrophils and macrophages than the former group regardless of its healing process in patients with H. pylori-positive GU.

CONCLUSION

Mucosal alpha- and beta-chemokines may be important to the ulcerogenesis in H. pylori-associated GU disease.

Estrogen induces the Akt-dependent activation of endothelial nitric-oxide synthase in vascular endothelial cells

Although estrogen is known to activate endothelial nitric oxide synthase (eNOS) in the vascular endothelium, the molecular mechanism responsible for this effect remains to be elucidated. In studies of both human umbilical vein endothelial cells (HUVECs) and simian virus 40-transformed rat lung vascular endothelial cells (TRLECs), 17beta-estradiol (E2), but not 17alpha-E2, caused acute activation of eNOS that was unaffected by actinomycin D and was specifically blocked by the pure estrogen receptor antagonist ICI-182,780. Treatment of both TRLECs and HUVECs with 17beta-E2 stimulated the activation of Akt, and the PI3K inhibitor wortmannin blocked the 17beta-E2-induced activation of Akt. 17beta-E2-induced Akt activation was also inhibited by ICI-182,780, but not by actinomycin D. Either treatment with wortmannin or exogenous expression of a dominant negative Akt in TRLECs decreased the 17beta-E2-induced eNOS activation. Moreover, 17beta-E2-induced Akt activation actually enhances the phosphorylation of eNOS. 17beta-E2-induced Akt activation was dependent on both extracellular and intracellular Ca(2+). We further examined the 17beta-E2-induced Akt activity in Chinese hamster ovary (CHO) cells transiently transfected with cDNAs for estrogen receptor alpha (ERalpha) or estrogen receptor beta (ERbeta). 17beta-E2 stimulated the activation of Akt in CHO cells expressing ERalpha but not in CHO cells expressing ERbeta. Our findings suggest that 17beta-E2 induced eNOS activation through an Akt-dependent mechanism, which is mediated by ERalpha via a nongenomic mechanism.

[A case of human chorionic gonadotropin-producing bladder cancer]

An 86-year-old man consulted our hospital complaining of gross hematuria. Cystoscopy revealed a nodular broad-based cancer at the dome of the bladder. The patient was initially treated by transurethral resection of bladder tumor. Since histological examination showed grade 3 transitional cell carcinoma containing giant cells that were positive for beta-human chorionic gonadotropin (beta-HCG), we made a diagnosis of beta-HCG-producing bladder cancer. Because of his advanced age and poor general condition, the patient underwent partial cystectomy alone without adjuvant chemotherapy. One month later, a chest X-ray film revealed multiple lung metastases, and he developed paraplegia of the lower extremities suggesting spinal metastases. One month later, he was brought to our hospital with cardiopulmonary arrest. This is, to our best knowledge, the 22nd case report of beta-HCG-producing bladder cancer in Japan.

Inhibition of BAD phosphorylation either at serine 112 via extracellular signal-regulated protein kinase cascade or at serine 136 via Akt cascade sensitizes human ovarian cancer cells to cisplatin

We studied the roles of the phosphatidylinositol 3-kinase (PI-3K)-protein kinase B/Akt-BAD cascade in both cisplatin-resistant Caov-3 and -sensitive A2780 human ovarian cancer cell lines. Treatment of both Caov-3 and A2780 cells with cisplatin but not with the trans-diaminodichloroplatinum (transplatin) isomer stimulated the activation of Akt, and the PI-3K inhibitor wortmannin blocked the cisplatin-induced activation of Akt. Treatment of both Caov-3 and A2780 cells with cisplatin but not with the trans-diaminodichloroplatinum isomer also stimulated the phosphorylation of BAD at both the Ser-112 and Ser-136 sites. Whereas the phosphorylation of BAD at Ser-136 was blocked by treatment with wortmannin, its phosphorylation at Ser-112 was blocked by a MAP/ERK kinase inhibitor, PD98059. Exogenous expression of a dominant-negative Akt in both Caov-3 and A2780 cells decreased the cell viability after treatment with cisplatin. In contrast, no sensitization to cisplatin was observed in cells expressing wild-type Akt. We further examined the role of BAD in the viability after cisplatin treatment using BAD mutants. Exogenous expression of each of the singly substituted BADS112A or BADS136A in both Caov-3 and A2780 cells decreased the viability after treatment with cisplatin to a degree intermediate between that caused by exogenous expression of wild-type BAD and doubly substituted BAD2SA. Cisplatin did not stimulate the phosphorylation of BAD Ser-136, but did stimulate the phosphorylation of BAD Ser-112 in cells expressing a dominant-negative Akt, suggesting that BAD Ser-136 but not Ser-112 was phosphorylated by Akt. Our findings suggest that cisplatin-induced DNA damage causes the phosphorylation of both BAD Ser-112 via an extracellular signal-regulated protein kinase (ERK) cascade and BAD Ser-136 via a PI-3K-protein kinase B/Akt cascade and that inhibition of either of these cascades sensitizes ovarian cancer cells to cisplatin.

Evaluation of a new care system provided to diabetic patients in the outpatient clinic

OBJECTIVE

Evaluation of metabolic states and chronic complications is essential for maintaining a high quality of care for diabetic patients. We have assessed the quality of care in routine outpatient clinics for diabetic subjects in our university hospital, and compared with those in a newly introduced standardized clinic to evaluate the new care system.

METHODS

The quality of care was assessed by the chart review in 1995, and compared with those from 1996-1997 in the "Diabetes Follow-up Clinic" which is systematically designed for the standardized care.

PATIENTS

The subjects were recruited among 860 patients who visited the outpatient clinic in July and August of 1995 with a diagnosis of diabetes or glucose intolerance. Six hundred seventy-two patients whose follow-up period had been more than 6 months with clinically diagnosed diabetes were used for the analysis.

RESULTS

Laboratory tests such as determination of HbA1c, and serum levels of lipids and creatinine were performed in more than 90% of the patients in the routine outpatient clinics. However, ophthalmology referral, 24-hour urine collection for the determination of creatinine clearance and albumin excretion, and electrocardiograms were not well performed and were incompletely documented (40-60% of the patients within a previous year and 70-80% in the last 2 years). In the standardized "Diabetes Follow-up Clinic", only four out of 555 diabetic patients failed to collect their 24-hour urine, and all participants had ankle blood pressure measurements, nerve conduction study, and nylon monofilament tests, etc. Furthermore, more than 95% of the patients had funduscopic examinations by ophthalmologists as well as records of electrocardiogram.

CONCLUSION

Introduction of the standardized "Diabetes Follow-up Clinic" may be one of the choices for increasing the quality of outpatient care and for the prevention of chronic diabetic complications.

Oral administration of tetrahydrobiopterin prevents endothelial dysfunction and vascular oxidative stress in the aortas of insulin-resistant rats

We have reported that a deficiency of tetrahydrobiopterin (BH(4)), an active cofactor of endothelial NO synthase (eNOS), contributes to the endothelial dysfunction through reduced eNOS activity and increased superoxide anion (O(2)(-)) generation in the insulin-resistant state. To further confirm this hypothesis, we investigated the effects of dietary treatment with BH(4) on endothelium-dependent arterial relaxation and vascular oxidative stress in the aortas of insulin-resistant rats. Oral supplementation of BH(4) (10 mg. kg(-1). d(-1)) for 8 weeks significantly increased the BH(4) content in cardiovascular tissues of rats fed high levels of fructose (fructose-fed rats). Impairment of endothelium-dependent arterial relaxation in the aortic strips of the fructose-fed rats was reversed with BH(4) treatment. The BH(4) treatment was associated with a 2-fold increase in eNOS activity as well as a 70% reduction in endothelial O(2)(-) production compared with those in fructose-fed rats. The BH(4) treatment also partially improved the insulin sensitivity and blood pressure, as well as the serum triglyceride concentration, in the fructose-fed rats. Moreover, BH(4) treatment of the fructose-fed rats markedly reduced the lipid peroxide content of both aortic and cardiac tissues and inhibited the activation of 2 redox-sensitive transcription factors, nuclear factor-kappaB and activating protein-1, which were increased in fructose-fed rats. The BH(4) treatment of control rats did not have any significant effects on these parameters. These results indicate that BH(4) augmentation is essential for the restoration of eNOS function and the reduction of vascular oxidative stress in insulin-resistant rats.

The Rayleigh Color Matches in Idiopathic Macular Holes Treated by Vitrectomy

Purpose: The Rayleigh color matches were measured to investigate the optical density in the cone photopigment of the central retina in patients with macular holes that had closed after vitrectomy.Methods: The Rayleigh equation was measured with the IF-2 anomaloscope in 7 patients with macular holes in one eye, that had closed after vitrectomy and gained an improvement in visual acuity of 0.5 or better. Reductions in the pigment optical density of cone photoreceptors of the opposite eyes were estimated with Rayleigh equations obtained in this experiment.Result: The Rayleigh equations of the affected eyes were shifted toward protanomalous setting compared with that of the opposite eyes. The optical densities of cone photoreceptors of the affected eyes were lower than those in the opposite eyes, even in patients with visual acuity of 1.0 or better.Conclusion: These findings suggest that the recovery of the visual acuity may precede that of the optical density in cone photopigment of central retina. The Rayleigh equation is more sensitive than visual acuity for evaluating visual function after vitrectomy for macular holes.

Usefulness of waveform analysis of popliteal artery in type II diabetic patients using gated magnetic resonance 2D-cine-PC imaging and 31P spectroscopy

AIMS/HYPOTHESIS

We studied 76 patients with Type II (non-insulin-dependent) diabetes mellitus and 16 age-matched non-diabetic subjects (control group) to clarify qualitative and quantitative abnormalities of waveform and flow volume of the popliteal artery.

METHODS

The 76 diabetic patients comprised 16 patients with occlusive arterial disease in the lower extremities [arteriosclerosis obliterans (ASO) group] and 60 patients free from this disease (non-ASO group). We flow analysed the popliteal artery and measured the phosphocreatine to inorganic phosphate ratio of resting plantar muscles to identify risk factors for foot lesions using gated magnetic resonance two-dimensional cine-mode phase-contrast imaging and 31P spectroscopy.

RESULTS

The control and non-ASO groups had a triphasic waveform with systolic, early and late diastolic components. All ASO patients had an abnormal monophasic waveform and a lower ankle brachial index than that of the control and non-ASO groups. To clarify the mechanism of reduced flow volume of lower extremities, we assigned the 60 patients of the non-ASO group to the three subgroups based on their levels of total flow volume of the popliteal artery. The lowest group showed an abnormal triphasic waveform with lower amplitudes of systolic and late diastolic components and flow velocities in foot arteries than those of the highest group although ABI was similar. From stepwise multiple regression analysis, late diastolic flow volume was identified as an independent determinant for the phosphocreatine to inorganic phosphate ratio (r2 = 0.484, p < 0.001).

CONCLUSION/INTERPRETATION

Waveform analysis of popliteal artery provides a powerful tool for identifying impaired peripheral circulation caused by either occlusive arterial disease or increased arterial resistance in diabetic patients.

Evidence that 3'-phosphorylated polyphosphoinositides are generated at the nuclear surface: use of immunostaining technique with monoclonal antibodies specific for PI 3,4-P(2)

Phosphatidylinositol (PI) 3,4-P(2) is a phosphoinositide that has been shown to be important for signal transduction in growth factor stimulation. We have produced monoclonal antibodies specific for PI 3,4-P(2), which were able to detect PI 3,4-P(2) generated in 293T cells treated with H(2)O(2), or in MKN45/BD110 cells expressing activated PI 3-kinase in immunostaining. Prolonged treatment with 0.05% Tween 20 resulted in detection of staining not only at the plasma membrane, but also at the nuclear surface, indicating that 3'-phosphorylated phosphoinositides can be generated and function in the nucleus.

Gastric metaplasia in the duodenal bulb shows increased mucosal interleukin-8 activity in Helicobacter pylori-positive duodenal ulcer patients

BACKGROUND

Although increased levels of interleukin (IL)-8 are known to be associated with infiltration of neutrophils in the gastric mucosa with Helicobacter pylori infection, no study has investigated the relationship between local IL-8 levels and neutrophil infiltration in the duodenal mucosa of patients with duodenal ulcer (DU).

METHODS

Duodenal mucosal biopsy specimens with and without gastric metaplasia (GM) were obtained from patients with DU and controls with an endoscopic methylene blue (MB) staining method. Levels of IL-8 secreted in the organ cultures of biopsy specimens were measured with an enzyme-linked immunosorbent assay. The number of myeloperoxidase-positive neutrophils infiltrating the lamina propria was determined in immunohistochemically stained tissue sections.

RESULTS

Histologic assessment showed that there was a strong correlation between the absence of endoscopic MB staining and the extent of GM. The levels of IL-8 in both duodenal and antral mucosal tissues were significantly higher in patients with H. pylori infection than in those without infection. In patients with DU the duodenal mucosal tissues with GM (MB-unstained mucosa) showed significantly higher levels of IL-8 than those without GM (MB-stained mucosa) or the antral mucosa. The number of neutrophils showed similar variations among DU and control patients with a positive correlation with IL-8 activity. The levels of IL-8 and the number of neutrophils decreased after H. pylori eradication in both duodenal and antral mucosal tissues, and these changes were more remarkable in the duodenal mucosal tissues with GM.

CONCLUSIONS

Increased IL-8 activity in the duodenal mucosa with GM may be important for ulcerogenesis in H. pylori-positive DU patients.

IDL can stimulate atherogenic gene expression in cultured human vascular endothelial cells

Previously, we have reported that the lipoprotein fraction containing intermediate density lipoprotein (IDL) and low density lipoprotein (LDL) isolated from diabetics stimulates an atherogenic cytokine in cultured endothelial cells. To study which lipoprotein fraction isolated from diabetics can modulate the gene expression in endothelial cells, we isolated IDL and LDL fractions from 14 type 2 diabetics and seven age- and BMI- adjusted non-diabetics. We measured the effects of the lipoproteins on mRNA expression of atherogenic molecules in cultured endothelial cells. We found that the IDL fraction stimulated monocyte chemoattractant protein-1 (MCP-1) mRNA expression in endothelial cells as time- and dose-dependent fashions, while the LDL fraction was not effective. IDL isolated from diabetics also increased not only platelet-derived growth factor B-chain, but also intercellular adhesion molecule-1 mRNA contents. Furthermore, the HbA(1c) levels in diabetics were significantly correlated with their abilities of IDL to increase MCP-1 mRNA content in the cells and the increment coincided with the increase in MCP-1 protein release into culture media. These results indicate that qualitative as well as quantitative changes in IDL fraction in diabetes are atherogenic through stimulating gene expression of atherogenic molecules in endothelial cells.

Troxipide, a novel antiulcer compound, has inhibitory effects on human neutrophil migration and activation induced by various stimulants

BACKGROUND

Neutrophils are considered to be involved in the pathogenesis of Helicobacter pylori-associated gastroduodenal diseases on account of their potent biological functions as effector cells. Troxipide, a new antiulcer compound used for patients with gastric ulcer or gastritis, has been shown to inhibit migration and activation of guinea pig neutrophils, but little is known about the pharmacological effects on human neutrophils.

AIMS

To study the effects of troxipide on chemotactic migration and superoxide generation by human neutrophils.

METHODS

The chemotactic response of neutrophils was determined in a multi-well chamber with a polycarbonate filter and the generation of O2- by neutrophils was measured using a chemiluminescence method. Concentrations of troxipide in gastric mucosa were measured by high-performance liquid chromatography.

RESULTS

Incubation of neutrophils with 10(-6) to 10(4) M troxipide caused inhibition of recombinant interleukin-8-induced migration. These concentrations of troxipide also inhibited superoxide generation by neutrophils stimulated by formyl-methionyl-leucyl-phenylalanine or platelet activating factor. These phenomena were not simply due to the direct cytotoxic effects since the above concentrations of troxipide did not induce neutrophil apoptosis. The concentrations of troxipide detected in the gastric mucosa after oral administration were in the range able to inhibit chemotactic migration and superoxide generation by neutrophils in vitro.

CONCLUSION

These results suggest that troxipide may exert its therapeutic effect in patients with gastric ulcer or gastritis by inhibiting inflammatory responses and mucosal injury mediated by neutrophils in gastric mucosa.

Estrogen suppresses transcription of lipoprotein lipase gene. Existence of a unique estrogen response element on the lipoprotein lipase promoter

Estrogen exerts a variety of effects not only on female reproductive organs but also on nonreproductive organs, including adipose tissue. Estrogen inhibits obesity triggered by ovariectomy in rodents. We studied the mechanism underlying this estrogen-dependent inhibition of obesity. Estrogen markedly decreased the amounts of fat accumulation and lipoprotein lipase (LPL) mRNA as well as triglyceride accumulation in genetically manipulated 3T3-L1 adipocytes stably expressing the estrogen receptor (ER). A pLPL(1980)-CAT construct, along with an ER expression vector, was introduced into differentiated 3T3-L1 cells, and CAT activities were determined. ER, mostly ligand-dependently, inhibited the basal LPL promoter activity by 7-fold. We searched the LPL promoter for an estrogen-responsive suppressive element by employing a set of 5'-deletion mutants of the pLPL-CAT reporter. Although there was no classical estrogen response element, it was demonstrated that an AP-1-like TGAATTC sequence located at (-1856/-1850) was responsible for the suppression of the LPL gene transcription by estrogen. An electrophoretic mobility shift assay probed with the TGAATTC sequence demonstrated formation of a specific DNA-nuclear protein complex. Interestingly, this complex was not affected by the addition of any antibodies against ER, c-Jun, c-Fos, JunB, or JunD. Because this TGAATTC element responded to phorbol ester and overexpression of CREB-binding protein abrogated the suppressive effect of estrogen on the LPL promoter, we conclude that a unique protein that is related to the AP-1 transcription factor families may be involved in the complex that binds to the TGAATTC element.

Evaluation of endothelial free radical release by vascular tension responses in insulin-resistant rat aorta

Mechanical responses to superoxide anion scavengers and nitric oxide (NO) synthase inhibitors in aortic endothelial cells were compared in normal chow-fed rats and those made insulin-resistant by feeding of fructose. Cu(2+), Zn(2+)-superoxide dismutase-induced vascular relaxation and superoxide production, measured by the lucigenin-enhanced chemiluminescence method, were greater in aortas from fructose-fed rats than in those from normal chow-fed rats. N(G)-nitro-L-arginine-induced contractions due to suppression of NO synthase activity were smaller in aortas from fructose-fed rats. Vascular mechanical responses may reflect the generation of superoxide and NO by the endothelium. Thus, isometric tension studies may be a useful tool for evaluating the production of these radicals in blood vessels.

Comparison between in vivo and in vitro chemokine production in Helicobacter pylori infection

BACKGROUND

Enhanced gastric mucosal chemokine activity has been demonstrated in patients with Helicobacter pylori infection. However, little is known about the mechanisms involved in this phenomenon.

AIM

To examine whether in vivo chemokine activity is similar to in vitro response of gastric epithelial cells infected by H. pylori.

PATIENTS AND METHODS

Antral biopsy specimens were obtained from patients with H. pylori infection for organ culture, isolation of H. pylori and histological examination.

RESULTS

In organ cultures of mucosal tissues, the levels of interleukin-8 and growth-related gene product a were elevated in patients with peptic ulcer disease compared with those with erosive gastritis or endoscopically normal mucosa. However, there were no significant differences in in vitro cultures of MKN45 or KATO III cells that were infected with H. pylori isolated from these same patients. These in vivo and in vitro alpha-chemokine levels showed no significant association with the presence of cagA gene and CagA protein, ureB genotype, or binding capacity to MKN45 or KATO III cells in individual H. pylori isolates. In contrast, in vivo mucosal alpha-chemokine activity correlated with H. pylori colonization density.

CONCLUSION

Mucosal chemokine profiles and inflammatory responses in H. pylori infection may be associated more closely with host factors, including those determining bacterial adhesiveness, than with differences in H. pylori strains.

[The Rayleigh color matches in idiopathic macular holes treated by vitrectomy]

PURPOSE

The Rayleigh color matches were measured to investigate the optical density in the cone photopigment of the central retina in patients with macular holes that had closed after vitrectomy.

METHODS

The Rayleigh equation was measured with the IF-2 anomaloscope in 7 patients with macular holes in one eye, that had closed after vitrectomy and gained an improvement in visual acuity of 0.5 or better. Reductions in the pigment optical density of cone photoreceptors of the opposite eyes were estimated with Rayleigh equations obtained in this experiment.

RESULT

The Rayleigh equations of the affected eyes were shifted toward protanomalous setting compared with that of the opposite eyes. The optical densities of cone photoreceptors of the affected eyes were lower than those in the opposite eyes, even in patients with visual acuity of 1.0 or better.

CONCLUSION

These findings suggest that the recovery of the visual acuity may precede that of the optical density in cone photopigment of central retina. The Rayleigh equation is more sensitive than visual acuity for evaluating visual function after vitrectomy for macular holes.

Scirrhous cancer of the stomach which survived for more than five years after neoadjuvant chemotherapy with UFT (uracil and tegafur) and cisplatin

A 68-year-old man was diagnosed as having a scirrhous cancer of the stomach. Carcinomatous peritonitis was suspected on abdominal CT examination. Three courses of uracil and tegafur (UFT)/cisplatin (CDDP) chemotherapy were administered. The primary foci were reduced in size, then total gastrectomy was performed. Histological findings revealed a poorly differentiated adenocarcinoma with scirrhous invasion into the subserosa. Histological efficacy of the chemotherapy was judged to be grade 2. The patient has been alive without disease for more than five years after total gastrectomy. Neoadjuvant chemotherapy with UFT and CDDP may have contributed to the favorable clinical outcome in this patient.

[Videoscopic surgical treatment for the patient of pleuroperitoneal communication complicating CAPD]

A 60-year-old female presented in end-stage renal failure. She was introduced continuous ambulatory peritoneal dialysis in August 1997. After about six months, acute hydrothorax developed in her right side of the pleural cavity. Then she was obligated to give up CAPD because of repeated recurrence of hydrothorax. She wanted to return to CAPD for her life style. In November 1998, she came to our hospital to have a surgical treatment for her pleuroperitoneal communication. We performed video assisted thoracoscopic surgery. Using methylene blue containing dialysis solution through CAPD catheter, we found a bleb on the diaphragm that expanded gradually. We diagnosed that potion was pleuroperitoneal communication. The defect of diaphragm was directly closed with surgical stapler. Post-operative course was very favorable. She could restarted CAPD at 3 postoperative day, and discharged from our hospital after 5 days of operation. No recurrence of hydrothorax has been detected for a years after the surgical treatment.

Volume-weighted mean nuclear volume. Is this new prognosticator comparable in different institutions?

OBJECTIVE

To determine whether volume-weighted mean nuclear volume (MNV) obtained at one institution is comparable to that from other institutions.

STUDY DESIGN

MNV calculated from histologic slides obtained at three hospitals--Shizuoka Prefectural Hospital (SPH), Shimada Municipal Hospital (SMH) and Shizuoka City Hospital (SCH)--were compared. Between December 1994 and June 1996, transurethral resection of bladder tumor or transurethral resection of the prostate was performed on 37 patients at SPH and 50 patients at SMH; histologic specimens from 40 cases of bladder tumors, 63 cases of normal bladder mucosa, 28 cases of benign prostatic hyperplasia and 1 case of prostate cancer were obtained. A portion of each specimen obtained at SPH or SMH was carried to SCH, and histologic slides were made at SCH using it. Using the remaining position of each specimen, histologic slides were then prepared at each hospital. Estimates of MNV were made from all histologic slides from each hospital, and the differences in MNV between the hospitals were analyzed. In addition, intraobserver and interobserver reproducibility were analyzed using 50 specimens obtained between December 1994 and August 1995.

RESULTS

On linear regression analysis, comparison of MNVs calculated from the histologic slides from SPH and SCH and those calculated from SMH and SCH revealed high correlation coefficients (R = .966 and .966, respectively), and the slope of the regression line did not differ significantly from unity. The paired t test also disclosed no significant difference between MNVs calculated at the two hospitals. Furthermore, the correlation coefficients for intraobserver and interobserver reproducibility of MNV estimates were also high (R = .918 and .949, respectively).

CONCLUSION

The results of this study indicate that estimates of MNV are comparable in multiple institutions, and we recommend that they be used to support subjective histologic grading.

1H- and 31P-magnetic resonance spectroscopy and imaging as a new diagnostic tool to evaluate neuropathic foot ulcers in Type II diabetic patients

AIMS/HYPOTHESIS

We studied 36 Type II (non-insulin-dependent) diabetic patients without occlusive arterial diseases in the lower extremities and 12 age-matched and sex-matched non-diabetic subjects to clarify the association between diabetic polyneuropathy and foot ulcers using 1H- and 31P-magnetic resonance spectroscopy and imaging.

METHODS

The 36 diabetic patients consisted of 12 patients with superficial foot ulcers and 24 patients free from this disease. We measured fat to water and phosphocreatine to inorganic phosphate (PCr:Pi) ratios and calculated the intracellular pH of resting plantar muscles by depth-resolved surface-coil spectroscopy using an 1H-31P double tuned coil. Furthermore, foot vasculature, fat and PCr contents of plantar muscles were visualised by phase-contrast angiography, T1-weighted spin-echo imaging and 31P-chemical shift imaging.

RESULTS

The 12 foot ulcer patients showed a reduced PCr to Pi ratio (p < 0.001) and peripheral nerve functions (p < 0.01-0.001) but an increased fat to water ratio (p < 0.001) and intracellular pH (p < 0.001) compared with the 24 patients without ulcers. From stepwise multiple regression analyses, motor nerve function as well as severity of nephropathy was associated with both fat to water and PCr to Pi ratios. When these patients were categorised into three groups based on their level of motor nerve function, the frequency of foot ulcers of the lowest group was higher than that of the highest group.

CONCLUSION/INTERPRETATION

Our findings indicated that motor nerve dysfunction in diabetic patients was closely associated with impaired energy metabolism, fatty infiltration and increased intracellular pH of plantar muscles and high frequency of foot ulcers. These new techniques could contribute to help clarify the predisposing factors for foot ulcers.

Endothelium-specific activation of NAD(P)H oxidase in aortas of exogenously hyperinsulinemic rats

To examine the effects of chronic hyperinsulinemia on vascular tissues, we examined the production of superoxide anion (O(-2)) in the aortic tissues of control and exogenously hyperinsulinemic rats performed by the implantation of an insulin pellet for 4 wk. O(-2) production by aortic segments from hyperinsulinemic rats was 2. 4-fold (lucigenin chemiluminescence method) and 1.7-fold (cytochrome c method) of that of control rats without any differences in O(-2) degrading activities in aortic tissues, respectively (P < 0.025). The increment was completely abolished in the presence of either 100 micromol/l apocynin (an inhibitor of NADPH oxidase) or 10 micromol/l diphenyleneiodonium (an inhibitor of flavin-containing enzyme) and was exclusively endothelium dependent. Consistently, NAD(P)H oxidase activities in endothelial homogenate in hyperinsulinemic rats were dose dependently stimulated above the values of control rats, although these activities in nonendothelial homogenate were not significantly stimulated by insulin. Furthermore, an insulin effect was also demonstrated 1 h after exposing aortic tissues to insulin. These results indicate that O(-2) production specifically increases in endothelium of aortic tissues in chronic hyperinsulinemic rats through the activation of NAD(P)H oxidase.

Abnormal biopterin metabolism is a major cause of impaired endothelium-dependent relaxation through nitric oxide/O2- imbalance in insulin-resistant rat aorta

To investigate underlying mechanisms responsible for the impaired nitric oxide (NO)-dependent vascular relaxation in the insulin-resistant state, we examined production of both NO and superoxide anion radical (O2-) and those modulating factors in aortas obtained from normal (CTR), insulin-treated (INS), or high fructose-fed (FR) rats. FR rats showed insulin resistance with endogenous hyperinsulinemia, whereas INS rats showed normal insulin sensitivity. Only FR aortic strips with endothelium elicited impaired relaxation in response to either acetylcholine or calcium ionophore A23187. Endothelial NO synthase (eNOS) activity and its mRNA levels were increased only in vessels from INS rats (P < 0.001), whereas eNOS activity in FR rats was decreased by 58% (P < 0.05) when compared with CTR rats. NO production from aortic strips stimulated with A23187 was significantly lower in FR than CTR rats. In contrast, A23187-stimulated O2- production was higher (P < 0.01) in FR than CTR rats. These differences were abolished when aortic strips were preincubated in the media including (6R)-5,6,7,8-tetrahydrobiopterin (BH4), an active cofactor for eNOS. Furthermore, as compared with CTR rats, aortic BH4 contents in FR rats were decreased (P < 0.001), whereas the levels of 7,8-dihydrobiopterin, the oxidized form of BH4, were increased, with opposite results in INS rats. These results indicate that insulin resistance rather than hyperinsulinemia itself may be a pathogenic factor for decreased vascular relaxation through impaired eNOS activity and increased oxidative breakdown of NO due to enhanced formation of O2- (NO/O2- imbalance), which are caused by relative deficiency of BH4 in vascular endothelial cells.

Estrogen activates telomerase

Telomerase activity is present in most malignant tumors and provides a mechanism for the unlimited potential for division of neoplastic cells. Although telomerase is known to be a regulated enzyme, the factors and mechanisms involved in telomerase regulation are not well understood. In the present study, we examined the effects of estrogen on telomerase activity. Telomerase activity in estrogen receptor (ER)-positive MCF-7 cells was up-regulated by the treatment with 17beta-estradiol. This activation accompanied up-regulation of the telomerase catalytic subunit, hTERT mRNA. Gel shift assays revealed that the imperfect palindromic estrogen-responsive element in the hTERT promoter specifically binds to ER. Transient expression assays using luciferase reporter plasmids containing various fragments of hTERT promoter showed that this imperfect palindromic estrogen-responsive element is responsible for transcriptional activation by ligand-activated ER. We also found that estrogen activates c-Myc expression in MCF-7 cells and that E-boxes in the hTERT promoter that bind c-Myc/Max play additional roles in estrogen-induced transactivation of hTERT. Estrogen thus activates telomerase via direct and indirect effects on the hTERT promoter. These findings may help elucidate the mechanisms of hormonal control of telomerase activity and aid understanding of the roles of sex steroids in cellular senescence and aging as well as estrogen-induced carcinogenesis.

Overexpression of core 2 N-acetylglycosaminyltransferase enhances cytokine actions and induces hypertrophic myocardium in transgenic mice

Elevated levels of glycocojugates, commonly observed in the myocardium of diabetic animals and patients, are postulated to contribute to the myocardial dysfunction in diabetes. Previously, we reported that UDP-GlcNAc: Galbeta1-3GalNAcalphaRbeta1-6-N-acetylglucosaminyltransferas e (core 2 GlcNAc-T), a developmentally regulated enzyme of O-linked glycans biosynthesis pathway, is specifically increased in the heart of diabetic animals and is regulated by hyperglycemia and insulin. In this study, transgenic mice overexpressing core 2 GlcNAc-T with severe increase in cardiac core 2 GlcNAc-T activities were normal at birth but showed progressive and significant cardiac hypertrophy at 6 months of age. The heart of transgenic mice showed elevation of sialylated O-glycan and increases of c-fos gene expression and AP-1 activity, which are characteristics of cardiac stress. Furthermore, transfection of PC12 cells with core 2 GlcNAc-T also induced c-fos promoter activation, mitogen activated-protein kinase (MAPK) phosphorylation, Trk receptor glycosylation, and cell differentiation. These results suggested a novel role for core 2 GlcNAc-T in the development of diabetic cardiomyopathy and modulation of the MAP kinase pathway in the heart.-Koya, D., Dennis, J. W., Warren, C. E., Takahara, N., Schoen, F. J., Nishio, Y., Nakajima, T., Lipes, M. A., King, G. L. Overexpression of core 2 N-acetylglycosaminyltransferase enhances cytokine actions and induces hypertrophic myocardium in transgenic mice.