Participation of nitric oxide in the mucosal injury of rat intestine induced by ischemia-reperfusion

The dual role of nitric oxide as a cytoprotective or a cytotoxic free radical gas has been noted in various types of pathophysiological conditions, including the digestive system. The aim of this study was to examine the role of nitric oxide in the mucosal injury induced by ischemia-reperfusion in the rat small intestine. A transient intestinal ischemia was produced in the catheterized ileal segments of rats by occluding the anterior mesenteric artery for 60 min. Nitric oxide metabolites (NO2- and NO3-) and lactate dehydrogenase activity in perfusates of the intestinal lumen were measured over 5 hr periods. The time-course of histological changes in small intestine was also observed. After ischemia-reperfusion, nitric oxide release in the intestinal lumen increased significantly and the dynamics of nitric oxide release correlated with that of lactate dehydrogenase leakage. The administration of NG-nitro-L-arginine methyl ester (1.0-2.5 mg/kg) inhibited this increased nitric oxide release and the lactate dehydrogenase leakage and afforded protection against the mucosal injury induced by ischemia-reperfusion. In conclusion, the nitric oxide production that was accelerated by ischemia-reperfusion of small intestine may possibly participate in the breakdown of intestinal mucosa after ischemia-reperfusion insult.

Effects of dienogest (a synthetic steroid) on coagulation, fibrinolysis, and platelet aggregation in female monkeys

We investigated the effects of dienogest (0.1-10 mg/kg per day, p.o.) on coagulation, fibrinolysis and platelet aggregation in female rhesus monkeys. Then, we also examined those of medroxyprogesterone acetate (MPA, 10 mg/kg per day, p.o.) or danazol (10-1000 mg/kg per day, p.o.) on these parameters in the same species. In addition, we assessed the effects of dienogest (1 and 3 mg/kg per day, p.o.) or MPA (10 mg/kg per day, p.o.) on platelet aggregation and platelet lipids in female cynomolgus monkeys. At doses of 0.3 mg/kg or greater, dienogest increased the levels of several coagulation and anticoagulation factors, but had no effect on the prothrombin time, activated partial thromboplastin time, fibrinolysis, or platelet aggregation. MPA (10 mg/kg) had no effect on coagulation or fibrinolysis, but significantly potentiated platelet aggregation in response to ADP and collagen and also increased the platelet cholesterol-to-phospholipid ratio. Danazol (10 mg/kg or more) increased the activities of coagulation factors V, VII, VIII, X, XI, and XII in comparison to dienogest and MPA. Consequently, dienogest caused less potentiation of platelet aggregation than MPA and less potentiation of coagulation than danazol.

Medium change amplifies mitogen-activated protein kinase-mediated prostaglandin E2 synthesis in Swiss 3T3 fibroblasts

In Swiss 3T3 fibroblasts, changing the culture medium prior to stimulation resulted in an augmentation of bradykinin-induced prostaglandin E2 synthesis. The augmentation depended on the duration of the exposure to the fresh medium, with a maximum effect at 1 h. Fetal calf serum in the fresh medium was essential for augmented prostaglandin E2 synthesis. The medium change slightly augmented the bradykinin-induced increase in intracellular free Ca2+ concentration and phosphoinositide hydrolysis with a different time course from that for prostaglandin E2 synthesis. 4',5,7-Trihydroxyisoflavone (genistein) and 3,4-dihydroxybenzylidene-malononitrile (tyrphostin 23), inhibitors of tyrosine kinases, and 2'-amino-3'-methoxyflavone (PD98059), an inhibitor of mitogen-activated protein kinase (MAPK) kinase, attenuated the increase in prostaglandin E2 synthesis. Bradykinin caused phosphorylation of cytosolic phospholipase A2 and p42/p44 MAPK, which was augmented by the medium change. From the results, it is concluded that activation of MAPK and cytosolic phospholipase A2 is involved in the augmentation of prostaglandin E2 synthesis produced by the medium change.

The effect of cold cardioplegic cardiac arrest and electrically induced ventricular fibrillation on human cardiac beta-adrenoceptors during open-heart surgery

This study was designed to test the hypothesis that distinct alterations in cardiac beta-adrenoceptors (betaARs) may occur during cardiopulmonary bypass (CPB) alone, during CPB with cold cardioplegic cardiac arrest (CCCA), and during CPB with electrically induced ventricular fibrillation (EIVF). We assessed the density and affinity of right atrial betaARs in 27 patients undergoing open-heart surgery by (-)-[125I]iodocyanopindolol binding before CPB, defined as the "control," immediately after initiation, defined as "before," and immediately before the cessation of CCCA or EIVF, defined as "after." The density of betaARs was equivalent between the "control" and "before" groups; however, during CPB with EIVF, the density of betaARs decreased significantly (P < 0.001), whereas during CPB with CCCA, it increased significantly (P < 0.01). The rate of changes of the betaAR density was not correlated with the "before"-"after" interval, and the affinity of the betaARs did not change throughout these CPBs. These findings demonstrate that: CPB alone does not affect cardiac betaARs, at least until the onset of EIVF or CCCA; CPB with EIVF induces rapid desensitization of cardiac betaARs; and CPB with CCCA induces rapid sensitization of cardiac betaARs.

GLUT1 glucose transporter: differential gene transcription and mRNA binding to cytosolic and polysome proteins in brain and peripheral tissues

The ratio of GLUT1 mRNA to actin mRNA in brain was 6- to 13- fold greater than the corresponding ratio in spleen, lung, testis, heart, and skeletal muscle in the rat. However, the ratio of GLUT1 transcription rate to actin transcription rate is comparable in brain and the five other organs. Organ extracts were fractionated into cytosol and polysomes, and ultraviolet light cross-linking studies were performed with these proteins and 32P-labeled GLUT1 mRNA containing the 3'-untranslated region (UTR) generated from transcription plasmids. The cytosol of brain, lung, spleen, C6 glioma cells in tissue culture, and freshly isolated bovine brain capillaries express a pair of 95 kDa and 74 kDa proteins, designated collectively as p88, and the polysome fraction of brain, testis, or C6 glioma cells express a 44-kDa protein, designated p44. In a middle cerebral artery occlusion model, brain cytosol p88 was up-regulated and p44 was down-regulated. These findings are consistent with the hypothesis that GLUT1 gene expression is subject to regulation at the post-transcriptional level.

Spiral computed tomography for bilioenteric anastomotic stricture

Spiral computed tomography scanning after intravenous cholangiography (IVC-SCT) was used to assess the anatomy of the biliary tree and anastomosis in a 7-year-old girl with recurrent cholangitis 5 years after surgical excision of a choledochal cyst. The technique clearly visualized the stenosis of the hepaticojejunostomy and hepatic duct and the dilated intrahepatic ducts. IVC-SCT provides a precise, prompt, and accurate image with minimal invasiveness and is especially suitable for the preoperative evaluation of pediatric patients.

Cystic lymphangioma of the scrotum

A 7-year-old boy who presented with a painful left hemiscrotal mass was diagnosed with acquired lymphangioma of the scrotum. Chronic friction from a cast for Perthes' disease might have been the cause of sudden enlargement of a congenital lymphangioma of the scrotum. Magnetic resonance imaging (MRI) was useful for preoperative diagnosis and determining the extent of the scrotal lesions. Total excision of the mass leaving the overlying skin was successfully performed. The clinical significance of MRI for preoperative diagnosis and planning surgical resection of this lesion is discussed.

Asp905Tyr polymorphism of the gene for the skeletal muscle-specific glycogen-targeting subunit of protein phosphatase 1 in NIDDM

OBJECTIVE

To clarify the contribution of the Asp905Tyr polymorphism of the muscle-specific glycogen-targeting subunit of protein phosphatase 1 (PP1G) to insulin resistance and related diseases.

RESEARCH DESIGN AND METHODS

We investigated the Asp905Tyr polymorphism of the PPP1R3 gene, which encodes the muscle-specific glycogen-targeting subunit of PP1G, in 259 Japanese patients with NIDDM and 194 healthy control subjects.

RESULTS

No significant difference was found in the genotype distribution between NIDDM patients (N = 259; Asp/Asp = 0.10, Asp/Tyr = 0.44, Tyr/Try = 0.46) and healthy control subjects (n = 194; Asp/Asp = 0.13, Asp/Tyr = 0.37, Tyr/Tyr = 0.50) or between patient groups subdivided by the mode of treatment: NIDDM patients with insulin therapy (Asp/Asp = 0.14, Asp/Tyr = 0.46, Tyr/Tyr = 0.40) and those without insulin therapy (Asp/Asp = 0.07, Asp/Tyr = 0.43, Tyr/Tyr = 0.50). However, NIDDM patients with the Tyr allele, which was previously reported to be associated with insulin resistance, tended to have lower BMIs than those without this allele (Asp/Asp: 24.5 +/- 1.1 kg/m2, Asp/Tyr: 22.6 +/- 0.4 kg/m2, Tyr/Tyr: 22.8 + 0.3 kg/m2, P = 0.06 by analysis of variance).

CONCLUSIONS

These data suggest that the Asp905Tyr polymorphism of the PPP1R3 gene is not associated with NIDDM or high BMI, both of which are known to be insulin-resistant states, in the Japanese population.

Rapid enlargement of a choledochal cyst: antenatal diagnosis and delayed primary excision

A case of choledochal cyst (CC) antenatally diagnosed at 29 weeks' gestation is reported. Rapid enlargement of the cyst soon after delivery resulted in complete gastric outlet obstruction (GOO). The lesion was treated by external drainage as a temporary maneuver, with delayed cyst excision and hepaticoduodenostomy at the hepatic hilum performed at 81 days of age. Surgical treatment of CC in early infancy has been reported to be safe and effective. However, delayed primary excision would be an alternative procedure, especially in rare cases showing rapid enlargement resulting in GOO, since this choice has the potential advantage of allowing weight gain and improved nutritional status without risking interim complications due to the drainage procedure.

CD45RChighCD4+ intestinal mucosal lymphocytes infiltrating in the inflamed colonic mucosa of a novel rat colitis model induced by TNB immunization

To clarify the role of CD4(+) intestinal mucosal lymphocytes in chronic intestinal inflammation, we developed a new rat colitis model by immunization with 2,4,6-trinitrobenzenesulfonic acid (TNB) in an emulsion with an adjuvant followed by transrectal administration of a low dose of TNB. Moreover, we assessed the therapeutic effect of anti-CD4 monoclonal antibody (mAb) on this model. In concert with the development ofserum anti-TNB Abs, transmural and segmental colitis that mimics some characteristics of human Crohn's disease was induced in the immunized rats. Immunohistochemical analysis showed the increase of infiltrating lamina propria CD4(+) T cells. Flow-cytometric analysis of isolated cells from inflamed mucosa revealed that CD45RChighCD4(+) T cells were significantly increased. Interestingly, intraperitoneal administration of anti-CD4 mAbs could suppress severe inflammation in the model with decrease of anti-TNB Ab titer. After the treatment with anti-CD4 mAbs, CD45RChighCD4(+) T cells in the lamina propria and interferon-gamma mRNA expression in the colonic lamina propria CD4(+) T cells were decreased. These results indicated that Th1 CD4(+) intestinal mucosal T cells have a role in the progress of inflamed lesions in chronic enteritis. They implicate that a therapy targeting mucosal T cells expressing CD4 may be feasible in the treatment of human Crohn's disease.

Supratentorial primitive neuroectodermal tumours: a report of four cases with an unusual clinical course in one patient

Four children, who were treated for supratentorial primitive neuro-ectodermal tumours between 1986 and 1995 at Kyushu University Hospital, are here presented. The initial characteristic symptoms and signs of these patients included vomiting and headache, followed by motor weakness. All patients underwent direct surgery for their tumours while 2 also received a course of postoperative radio-therapy. After these treatments, 3 died within 4 months after diagnosis, whereas one infant, who underwent a total removal of the tumour but had no adjuvant therapy, is still alive after a follow-up period of 4 years. Most of the tumour cells of these 4 cases were poorly differentiated neuro-ectodermal cells, but some also showed variable differentiation along the glial and/or neuronal lines. While such differentiation had no impact on the clinical course of the patients, the malignant potential as assessed by the percentage of MIB1-positive cells showed a good correlation with the clinical features; the 3 cases with a rapid clinical course had MIB1 staining indices of more than 2%, and one case, who survived more than 4 years, had the same indices of 0.2% as found in benign tumours. Although "PNETs" of Hart and Earl share certain clinical features, they may be a group of tumours heterogeneous in their origins, histogenesis, and biological behaviours.

Influence of interindividual variability of aldose reductase protein content on polyol-pathway metabolites and redox state in erythrocytes in diabetic patients

OBJECTIVE

To clarify the influence of interindividual difference in the level of aldose reductase on the polyol pathway-related metabolism in diabetic patients.

RESEARCH DESIGN AND METHODS

The enzyme protein content was determined by a two-site enzyme-linked immunosorbent assay using monoclonal and polyclonal antibodies to recombinant human aldose reductase in erythrocytes from 35 diabetic patients and 11 healthy volunteers. Patients were stratified into two groups by the median of aldose reductase content, and the erythrocyte sorbitol level, the fructose level, and the lactate-to-pyruvate ratio were compared between the two groups. We also examined the correlation of the enzyme content with these metabolic parameters.

RESULTS

The group of patients whose enzyme content was above the median showed a significant increase in the levels of sorbitol (34.7 +/- 4.9 vs. 20.4 +/- 2.0 nmol/g Hb, P < 0.05) and fructose (99.8 +/- 17.2 vs. 45.9 +/- 4.6 nmol/g Hb, P < 0.05), along with an elevated lactate-to-pyruvate ratio (28.6 +/- 6.1 vs. 11.7 +/- 1.2, P < 0.05), compared with patients with low enzyme levels. The aldose reductase content in erythrocytes was well correlated with its activity, and there was a significant correlation between the enzyme content and the erythrocyte sorbitol (r = 0.58, P < 0.001) or fructose (r = 0.57, P < 0.001) levels as well as between the enzyme level and the lactate-to-pyruvate ratio (r = 0.38, P < 0.05).

CONCLUSIONS

These results suggest that the interindividual variability of aldose reductase content may contribute tangibly to the polyol-pathway flux and cytoplasmic redox alteration in diabetic patients.

In vivo formation of a Schiff base of aminoguanidine with pyridoxal phosphate

Aminoguanidine (AG) is considered to be a promising compound for the treatment of diabetic complications. We examined the in vitro and in vivo formation of Schiff bases of AG with pyridoxal 5'-phosphate (PLP) and pyridoxal (PL). AG reacted in vitro far more rapidly with PLP to form a Schiff base (PLP-AG) than with PL to form another Schiff base (PL-AG). Administration of AG at 7 mM in drinking water for 18 weeks caused the formation of PLP-AG in the liver and kidney of mice (12.1 +/- 1.6 and 3.8 +/- 0.64 nmol/g of tissue, respectively, mean +/- SD, N = 6). The amount of PLP in the liver of mice AG administered was significantly lower than that of control mice (4.0 +/- 1.4 vs 17.4 +/- 1.3 nmol/g of wet tissue, mean +/- SD, N = 6). Simultaneous administration of pyridoxine (1 mM in drinking water) with AG (7 mM in drinking water) did not ameliorate the decrease in tissue PLP and caused the excess formation of PLP-AG. The results suggest that attention should be paid to the deficiency of tissue PLP in the clinical use of AG.

Immunohistochemical expression of tyrosine kinase (Trk) receptor proteins in mature neuronal cell tumors of the central nervous system

The interactions of neurotrophins with the Trk family of tyrosine kinase receptors result in growth and maturational changes in neuronal cells. Although the histogenesis of brain tumors composed of mature neuronal cells is still not completely understood, neurotrophins and Trk receptors may be involved in the evolution, maturation, and persistence of these tumors. The clinical and anatomic pathological features of 8 primary neuronal cell tumors (ganglioglioma: 3 cases, cerebral neurocytoma: 3 cases, intraventricular neurocytoma: 2 cases) occurring in the central nervous system (CNS) have been examined. In addition to routine histological examinations, immunohistochemistry was used to evaluate the expression of neurotrophin receptors (TrkA, TrkB) and of neuronal differentiation markers such as neuron-specific enolase, neurofilament, synaptophysin, and chromogranin A. While neither TrkA nor TrkB expression was demonstrated in 2 intraventricular neurocytomas, the remaining 6 tumors did show positive immunohistochemical staining for TrkA and/or TrkB proteins; for TrkA protein, ganglionic cells showed membraneous or cytoplasmic staining, while small non-ganglionic neuronal cells with scant cytoplasm occasionally showed positive cytoplasmic immunoreactivity. For TrkB protein, small non-ganglionic neuronal cells showed a more intense immunoreaction than ganglionic cells. Gangliogliomas with high TrkA and TrkB expression showed higher levels of neuronal differentiation, as demonstrated by the neuron-specific enolase and neurofilament immunoreactivity. The existence of neurotrophin receptors in the tumor cells thus suggests that neurotrophic influence are involved in the evolution and subsequent cellular maturation in neuronal cell tumors of the CNS.

Ovarian teratoma with gliomatosis peritonei: report of two cases

Gliomatosis peritonei, a rare condition related to ovarian teratomas, involves the peritoneal implantation of numerous nodules of predominantly mature glial tissues. We report herein the cases of two patients with immature ovarian teratoma associated with gliomatosis peritonei, in one of whom a rapid progression of teratomatous implants occurred 14 weeks after her initial surgery. Gliomatosis peritonei is considered benign in most cases; however, some reports have documented the rapid recurrence of immature peritoneal implants, as implantation is associated with teratomas of all grades. Thus, in the face of peritoneal implants suspected to be of a teratomatous nature, thorough and extensive sampling is essential to exclude the presence of immature elements which may imply a poor prognosis and require aggressive therapy.

Sequential percutaneous microwave coagulation therapy for liver tumor

BACKGROUND

Percutaneous microwave coagulation therapy (PMCT) is effective for small liver tumors. To enhance the radicality of PMCT, we developed a sequential coagulation technique.

METHODS

After inserting the first guide-needle under sonography, multiple needles were placed through a disk-type introducer that was devised to guide needle puncture at regular intervals, and microwaves were irradiated. Six patients, including 4 with hepatocellular carcinoma and 2 with liver metastasis, underwent this technique for tumors of 15 to 80 mm in diameter.

RESULTS

This technique can coagulate an area up to 60 mm in diameter in one session. Insertion of multiple needles, ranging from 2 to 11, was successful without complications. Three patients undergoing curative PMCT developed no tumor recurrence. The other 3 received incomplete PMCT due to the large size and location of the tumor.

CONCLUSIONS

This preliminary study indicates the efficacy of this technique to facilitate and secure PMCT in selected patients with liver tumors.

Association of distal chromosome 2q with IDDM in Japanese subjects

An insulin-dependent diabetes mellitus (IDDM)-susceptibility gene (IDDM13) has recently been mapped to a region of distal chromosome 2q, which is syntenic to the region of mouse chromosome 1 containing a murine susceptibility gene for IDDM, Idd5. To determine the contribution of this region to IDDM disease susceptibility further and to narrow the region for positional cloning of susceptibility genes, we have studied the association of distal chromosome 2q with IDDM in the genetically distinct Japanese population. A 137 mobility unit (mu) allele at D2S137 locus was significantly associated with IDDM (odds ratio 1.92, p = 0.0016). Other markers, D2S301 and D2S143, located in the same region were not associated with IDDM, indicating that IDDM13 is in linkage disequilibrium with D2S137, but not with D2S301 or D2S143. The association of D2S137 with IDDM was observed in patients lacking one of two high risk HLA alleles, DQBI*0303 and DQBI*0401, but not in patients with either of these alleles. The frequency of high risk HLA alleles was significantly lower in patients with the susceptible allele at D2S137, suggesting that IDDMI3 contributes to IDDM susceptibility in subjects without high risk genotypes at IDDM1. Demonstration of allelic association of D2S137 with IDDM localizes IDDM13 in the close vicinity (<2 centiMorgans) of D2S137, greatly facilitating fine structure mapping and positional cloning of IDDM13.

Induction of Leydig cell tumors by lacidipine via up-regulation of the LHRH receptor on Leydig cells in rats

Long-term (78 weeks) administration of lacidipine, a dihydropyridine calcium antagonist, increased the incidence of Leydig cell tumors (LCTs) in Sprague-Dawley rats. Lacidipine also increased and decreased the plasma luteinizing hormone (LH) and testosterone levels, respectively. Leydig cells from lacidipine-treated rats showed increases in luteinizing hormone-releasing hormone (LHRH) receptor expression, protein kinase C (PKC) activity, expression of proto-oncogenes, and 5-bromodeoxyridine uptake; whereas their calcium level, LH receptors, and testosterone content decreased. These data suggest that LHRH receptors play an important role in the development of rat LCTs induced by lacidipine, which activates a cascade of cell cycle-regulatory genes via PKC. When isolated Leydig cells were cultured with lacidipine or nicardipine, these changes in rat Leydig cells were not demonstrable in mice and monkeys, species having many fewer testicular LHRH receptors than rats. Thus, lacidipine may pharmacologically induce LCTs in rats but not in mice, with the difference depending on the presence or absence of testicular LHRH receptors. The induction of LCTs by lacidipine in rats is unlikely to occur in humans, since their Leydig cells lack LHRH receptors.

Meta-analysis of association of insertion/deletion polymorphism of angiotensin I-converting enzyme gene with diabetic nephropathy and retinopathy

An insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene has repeatedly been shown to be associated with ischaemic heart disease, but the association of this genetic marker with diabetic microangiopathy is controversial. To assess the association of the genotypes with the development of diabetic nephropathy or retinopathy, we performed a meta-analysis of data from the literature, using Mantel-Haenszel method followed by the Breslow-Day test for assessing homogeneity among data. In a total of 4773 diabetic patients from 18 studies with (n = 2495) and without (n = 2278) renal complications, the D allele was significantly associated with diabetic nephropathy (p < 0.0001) in a dominant model (summary odds ratio 1.32, 95% confidence interval: 1.15 to 1.51). There was no significant evidence against homogeneity of the odds ratios (chi(2) = 18.9, 20 df; p = 0.53). The association was significant both in non-insulin-dependent (p < 0.005) and in insulin-dependent diabetes mellitus (p < 0.05). Likewise, in a total of 2010 diabetic patients with (n = 1008) and without (n = 1002) retinopathy, there was no association of the I/D polymorphism with diabetic retinopathy. These data suggest that the ACE I/D polymorphism affects the risk for diabetic nephropathy, but not for diabetic retinopathy.

Electroretinogram in sucrose-fed diabetic rats treated with an aldose reductase inhibitor or an anticoagulant

To investigate the role of increased polyol pathway activity and hemodynamic deficits in the pathogenesis of diabetic retinopathy in non-insulin-dependent diabetes mellitus (NIDDM), Otsuka Long-Evans Tokushima fatty (OLETF) rats, an animal model of human NIDDM, were given water with or without 30% sucrose and some of them were fed laboratory chow containing 0.03% cilostazol, an anticoagulant, or 0.05% [5-(3-thienyl)tetrazol-1-yl] acetic acid monohydrate (TAT), an aldose reductase inhibitor, for 8 wk. Long-Evans Tokushima Otsuka (LETO) rats were used as nondiabetic controls. The peak latencies of oscillatory potentials of the electroretinogram in sucrose-fed OLETF rats were significantly prolonged compared with those in OLETF rats without sucrose feeding and LETO rats. There was a marked increase in platelet aggregability and a significant decrease in erythrocyte 2,3-diphosphoglycerate in sucrose-fed OLETF rats. Cilostazol significantly improved these parameters without changes in retinal levels of sorbitol and fructose. TAT, however, ameliorated all of these parameters. These findings confirm that the sucrose-fed OLETF rat is a useful animal model of retinopathy in human NIDDM and suggest that cilostazol improved diabetic retinopathy by modifying vascular factors, not by altering polyol pathway activity.