Reactive nitrogen oxide species induce dilatation of the intercellular space of rat esophagus

OBJECTIVE

Dilatation of the intercellular space (DIS) of the esophageal epithelium is recognized as one of the earliest histological changes in gastroesophageal reflux disease patients. At the human gastroesophageal junction, reactive nitrogen oxide species (RNOS) are generated luminally through the entero-salivary re-circulation of dietary nitrate. In cases with gastroesophageal reflux, the site of luminal RNOS generation may shift to the distal esophagus. The aim of this study was to investigate whether luminal RNOS exposure could be involved in the pathogenesis of DIS.

MATERIAL AND METHODS

Rat esophageal mucosa was studied with an Ussing chamber model. On the luminal side of the chamber, RNOS were generated by the acidification of physiologic concentrations of sodium nitrite (1.0 or 5.0 mM). Esophageal barrier function was assessed by means of electrophysiological transmembrane resistance and membrane permeability by means of (3)H-mannitol flux. The dimensions of the intercellular spaces were assessed by using transmission electron microscopy.

RESULTS

Administration of acid plus sodium nitrite induced DIS of the esophageal epithelium, and this ultrastructural morphological change was accompanied by a concomitant decrease in the transmembrane resistance and an increase in the epithelial permeability. The DIS induced by luminal RNOS was also confirmed in an in vivo exposure model.

CONCLUSIONS

The present animal study indicates that the RNOS generated by the acidification of salivary nitrite in the presence of refluxed gastric acid in the esophagus could be a luminal factor that is responsible for the induction of DIS. Further studies are warranted to investigate the clinical relevance of the present findings to the human situation.

Gastric variceal rupture successfully treated with repeated EIS and EVL

A 68-year-old female with liver cirrhosis presented at the Emergency Room of our hospital with copious tarry stools. Upper gastrointestinal endoscopy showed an isolated gastric variceal rupture, and we performed endoscopic injection sclerotherapy using cyanoacrylate, on four occasions, resulting in successful hemostasis. Injection of CA is a useful emergency treatment option for gastric variceal bleeding without gastro-renal shunt.

Enhanced expression of mRNA for FK506-binding protein 5 in bone marrow CD34 positive cells in patients with rheumatoid arthritis

OBJECTIVE

Recent studies have disclosed that several genes are up-regulated in bone marrow (BM) mononuclear cells from rheumatoid arthritis (RA) patients. However, it remains unclear whether such abnormalities result from systemic inflammation or from abnormalities at stem cell level. The current study therefore examined the expression of several representative genes, including amphiregulin (AREG), chemokine receptor 4 (CXCR4), and FK506-binding protein 5 (FKBP5) in RA BM CD34+ cells.

METHODS

BM samples were obtained from 52 patients with RA and 35 patients with osteroarthritis (OA) during joint operations. CD34+ cells were purified from the BM mononuclear cells by positive selection with magnetic beads. The mRNA expression for AREG, CXCR4, and FKBP5 was measured using quantitative real-time PCR.

RESULTS

The expression of mRNA for FKBP5, but not that of AREG or CXCR4, was significantly higher in RA BM CD34+ cells than in OA BM CD34+ cells. The FKBP5 mRNA expression level was not correlated with serum CRP or treatment. In addition, tumour necrosis factor-alpha did not enhance the expression of FKBP5 mRNA in BM CD34+ cells from healthy donors.

CONCLUSION

The results suggest that the enhanced expression of FKBP5 in BM CD34+ cells might be an intrinsic abnormality of RA BM CD34+ cells, whereas the enhanced expression of AREG and CXCR4 in BM mononuclear cells might be secondary to systemic inflammation.

Portal vein thrombosis treated using danaparoid sodium and antithrombin III

A 45-year-old man under treatment for liver cirrhosis (LC) due to chronic hepatitis C and hemophilia A was seen in our emergency room because of a 10-kg weight gain in the previous week due to ascites. Portal vein thrombosis (PVT) was detected with computer tomography (CT) and ultrasonographic (US). Danaparoid sodium (DS) and antithrombin III (AT III) were administrated and doppler US images showed improvement of portal venous blood flow. DS or AT III may be safe and alternative therapies for PVT.

Involvement of JNK pathway in the promotion of the early stage of colorectal carcinogenesis under high-fat dietary conditions

BACKGROUND AND AIMS

The molecular mechanisms underlying the promotion of colorectal carcinogenesis by a high-fat diet (HFD) remain unclear. We investigated the role of the insulin-signal pathway and the c-Jun N-terminal kinase (JNK) pathway, which reportedly play crucial roles in insulin resistance, during colorectal carcinogenesis in the presence of hyperinsulinaemia induced by a HFD.

METHODS

Azoxymethane-induced aberrant crypt foci formation and cell proliferation in the colonic epithelium were compared between mice fed a normal diet (ND) and mice fed a HFD. A western blot analysis was performed to elucidate the mechanism affecting colorectal carcinogenesis by a HFD.

RESULTS

The number of aberrant crypt foci and the colonic epithelial cell proliferative activity were significantly higher in the HFD group than in the ND group. While the plasma insulin level was significantly higher in the HFD group than in the ND group, a western blot analysis revealed the inactivation of Akt, which is located downstream of the insulin receptor, in the colonic epithelia of the HFD group. On the other hand, JNK activity was significantly higher in the HFD group than in the ND group. A JNK specific inhibitor significantly suppressed the increase in epithelial cell proliferation only under a HFD, but not under a ND.

CONCLUSIONS

Colonic cell proliferation was promoted via the JNK pathway in the presence of a HFD but not in the presence of a ND. This novel mechanism may explain the involvement of the JNK pathway in the effect of dietary fat intake on colon carcinogenesis.

Risk factors for the progression of endoscopic Barrett's epithelium in Japan: a multivariate analysis based on the Prague C & M Criteria

PURPOSE

To determine the prevalence and progression of Barrett's epithelium and associated risk factors in Japan.

METHODS

The study population comprised 869 cases. Endoscopic Barrett's epithelium was diagnosed based on the Prague C & M Criteria. The correlations of clinical factors with the prevalence and progression of endoscopic Barrett's epithelium were examined.

RESULTS

Endoscopic Barrett's epithelium was diagnosed in 374 cases (43%), in the majority of which the diagnosis was short-segment Barrett's esophagus. The progression of Barrett's epithelium was identified in 47 cases. In univariate and multiple logistic regression analyses, aging, smoking habit, and erosive esophagitis were significantly associated with the prevalence of Barrett's epithelium, whereas aging and erosive esophagitis, especially severe erosive esophagitis, were significant contributing factors to the progression of Barrett's epithelium.

CONCLUSIONS

Forty-three percent of the total study population was diagnosed as having endoscopic Barrett's epithelium. During the follow-up period, 12.6% of the cases with Barrett's epithelium exhibited progression which was associated with aging and severe erosive esophagitis.

Pharmacokinetics of 5-fluorouracil in elderly Japanese patients with cancer treated with S-1 (a combination of tegafur and dihydropyrimidine dehydrogenase inhibitor 5-chloro-2,4-dihydroxypyridine)

S-1 is an oral anticancer agent that combines tegafur, a prodrug of 5-fluorouracil (5-FU), and 5-chloro-2,4-dihydroxypyridine (CDHP), an inhibitor of dihydropyrimidine dehydrogenase. We examined the effects of aging on the pharmacokinetics of the components of S-1. The median area under the concentration-time curve (AUC) of active 5-FU did not significantly differ between 10 patients 75 years or older and 53 patients younger than 75 years (P = 0.598, Mann-Whitney U test). It is interesting to note that the median oral clearance of tegafur in patients 75 years or older was significantly lower than that in patients younger than 75 years (P = 0.011). Furthermore, the median AUC of CDHP was significantly higher in patients 75 years or older than in those younger than 75 years (P = 0.004). This effect was caused by reduced renal function in the elderly, because CDHP is excreted in the urine by glomerular filtration. The opposing effects of aging on the oral clearance of tegafur and the AUC of CDHP may offset each other, leading to unchanged systemic exposure of 5-FU.

The alpha/beta interfaces of alpha(1)beta(1), alpha(3)beta(3), and F1: domain motions and elastic energy stored during gamma rotation

ATP synthase (F(o)F(1)) consists of F(1) (ATP-driven motor) and F(o) (H(+)-driven motor). F(1) is a complex of alpha(3)beta(3)gammadeltaepsilon subunits, and gamma is the rotating cam in alpha(3)beta(3). Thermophilic F(1) (TF(1)) is exceptional in that it can be crystallized as a beta monomer and an alpha(3)beta(3) oligomer, and it is sufficiently stable to allow alphabeta refolding and reassembly of hybrid complexes containing 1, 2, and 3 modified alpha or beta. The nucleotide-dependent open-close conversion of conformation is an inherent property of an isolated beta and energy and signals are transferred through alpha/beta interfaces. The catalytic and noncatalytic interfaces of both mitochondrial F(1) (MF(1)) and TF(1) were analyzed by an atom search within the limits of 0.40 nm across the alphabeta interfaces. Seven (plus thermophilic loop in TF(1)) contact areas are located at both the catalytic and noncatalytic interfaces on the open beta form. The number of contact areas on closed beta increased to 11 and 9, respectively, in the catalytic and noncatalytic interfaces. The interfaces in the barrel domain are immobile. The torsional elastic strain applied through the mobile areas is concentrated in hinge residues and the P-loop in beta. The notion of elastic energy in F(o)F(1) has been revised. X-ray crystallography of F(1) is a static snap shot of one state and the elastic hypotheses are still inconsistent with the structure, dyamics, and kinetics of F(o)F(1). The domain motion and elastic energy in F(o)F(1) will be elucidated by time-resolved crystallography.

Aperitif effects on gastric emptying: a crossover study using continuous real-time 13C breath test (BreathID System)

The aim of this study was to determine whether there is a correlation between aperitif and gastric emptying. Ten healthy male volunteers participated in this randomized, two-way crossover study. Under two conditions (after drinking an aperitif versus not), the (13)C breath test was performed for 4 h with a liquid meal (200 kcal/200 ml) containing 100 mg (13)C acetate. We used 50 ml of umeshu as the aperitif. This is a traditional Japanese plum liqueur, and contains 7 ml alcohol (14%). In the aperitif group, T(1/2), T(lag), and T(peak) were significantly delayed [T(1/2) (132: 113-174) versus (112: 92-134) (P = 0.0069); T(lag) (80: 63-94) versus (55: 47-85) (P = 0.0069); and T(peak) (81: 62-96) versus (54: 34-84) (P = 0.0069), (median: range, aperitif versus control, min)]. Gastric emptying was significantly delayed in the aperitif group as compared with the control group. This study revealed that even a small amount of alcohol such as an aperitif may contribute to delayed gastric emptying.

[Tricuspid annuloplasty, pulmonary valve replacement, ventricular septal defect (VSD) patch closure, and right-sided maze procedure 23-years after corrective repair of tetralogy of Fallot]

Postoperative pulmonary valve regurgitation, stenosis of the right ventricular outflow tract, conduit failure, ventricular septal patch leak, secondary tricuspid valve regurgitation, and various arrhythmias are the major complications that develop after surgical repair of tetralogy of Fallot in adults. A 27-year-old male with pulmonary regurgitation, tricuspid regurgitation, residual ventricular septal defect (VSD), low left ventricular function, and chronic atrial fibrillation underwent tricuspid annuloplasty, pulmonary valve replacement with a stentless aortic valve, VSD patch closure, and right-sided maze procedure, and the postoperative course was uneventful. The cardiothoracic ratio decreased, sinus rhythm was restored, and the patient's complaints were relieved. Reoperation at the optimal time after corrective repair of tetralogy of Fallot in adults may improve the outcome.

Fixed dosing and pharmacokinetics of S-1 in Japanese cancer patients with large body surface areas

BACKGROUND

S-1 is an oral anticancer agent that combines tegafur (FT) with 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate. The recommended initial dose of S-1 is 120 mg/day for patients with a body surface area (BSA) of > or =1.5 m(2) in Japan.

METHODS

We examined the effects of using this fixed dose on the pharmacokinetics of FT, CDHP, and active 5-fluorouracil (5-FU) on the basis of actual BSA. The pharmacokinetics was compared between patients with a BSA of 1.5-1.75 m(2) and those with a BSA of > or =1.75 m(2).

RESULTS

The median areas under the time-concentration curves (AUCs) of 5-FU and CDHP were significantly lower in patients with a BSA of > or =1.75 m(2) than in those with a BSA of 1.5-1.75 m(2) (P = 0.005 and 0.006, respectively; Mann-Whitney U-test). There was no difference between the groups in the median AUC of FT.

CONCLUSION

Systemic exposure to 5-FU is significantly lower in Japanese cancer patients with a large BSA of >1.75 m(2) who received the recommended fixed dose of S-1.

Adiponectin suppresses colorectal carcinogenesis under the high-fat diet condition

BACKGROUND AND AIMS

The effect of adiponectin on colorectal carcinogenesis has been proposed but not fully investigated. We investigated the effect of adiponectin deficiency on the development of colorectal cancer.

METHODS

We generated three types of gene-deficient mice (adiponectin-deficient, adiponectin receptor 1-deficient, and adiponectin receptor 2-deficient) and investigated chemical-induced colon polyp formation and cell proliferation in colon epithelium. Western blot analysis was performed to elucidate the mechanism which affected colorectal carcinogenesis by adiponectin deficiency.

RESULTS

The numbers of colon polyps were significantly increased in adiponectin-deficient mice compared with wild-type mice fed a high-fat diet. However, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. A significant increase in cell proliferative activity was also observed in the colonic epithelium of the adiponectin-deficient mice when compared with wild-type mice fed a high-fat diet; however, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. Similarly, an increase in epithelial cell proliferation was observed in adiponectin receptor 1-deficient mice, but not in adiponectin receptor 2-deficient mice. Western blot analysis revealed activation of mammalian target of rapamycin, p70 S6 kinase, S6 protein and inactivation of AMP-activated protein kinase in the colon epithelium of adiponectin-deficient mice fed with high-fat diet.

CONCLUSIONS

Adiponectin suppresses colonic epithelial proliferation via inhibition of the mammalian target of the rapamycin pathway under a high-fat diet, but not under a basal diet. These studies indicate a novel mechanism of suppression of colorectal carcinogenesis induced by a Western-style high-fat diet.

Effectiveness of antiplatelet drugs against experimental non-alcoholic fatty liver disease

OBJECTIVE

No effective drugs have been developed to date to prevent or treat non-alcoholic fatty liver disease (NAFLD), although diet modification and exercise to improve obesity have been attempted. Therefore, development of a novel drug/strategy to treat NAFLD is urgently needed. In the present study, a novel concept is proposed for the treatment of NAFLD.

METHODS

Fisher 344 male rats were given a choline-deficient, l-amino acid-defined (CDAA) diet or a high-fat high-calorie (HF/HC) diet with or without the antiplatelet agents, aspirin, ticlopidine or cilostazol for 16 weeks. Liver steatosis, inflammation and fibrosis, and the possible mechanisms involved were investigated.

RESULTS

All three antiplatelet drugs, namely aspirin, ticlopidine and cilostazol, significantly attenuated liver steatosis, inflammation and fibrosis in the CDAA diet group. Of the three agents, cilostazol was the most effective, and the drug also suppressed HF/HC diet-induced liver steatosis. Cilostazol appeared to exert its beneficial effect against NAFLD by suppressing mitogen-activated protein kinase activation induced by oxidative stress and platelet-derived growth factor via intercepting signal transduction from Akt to c-Raf.

CONCLUSION

Antiplatelet agents, especially cilostazol, offer the promise of becoming key agents for the treatment of NAFLD.