Ghrelin is present in pancreatic alpha-cells of humans and rats and stimulates insulin secretion.

Ghrelin, a novel growth hormone-releasing peptide isolated from human and rat stomach, is a 28-amino acid peptide with a posttranslational acylation modification that is indispensable for stimulating growth hormone secretion by increasing intracellular Ca(2+) concentration. It also functions in the regulation of feeding behavior, energy metabolism, and gastric acid secretion and motility. Using two different antibodies against the NH(2)- and COOH-terminal regions of ghrelin, we studied its localization in human and rat pancreas by immunohistochemistry. Ghrelin-immunoreactive cells were identified at the periphery of pancreatic islets in both species. Ghrelin co-localized exclusively with glucagon in rat islets, indicating that it is produced in alpha-cells. We identified ghrelin and des-acyl ghrelin in the rat pancreas using reverse-phase high-performance liquid chromatography combined with two radioimmunoassays. We also detected mRNA encoding ghrelin and its receptor in the rat pancreatic islets. Ghrelin increased the cytosolic free Ca(2+) concentration in beta-cells and stimulated insulin secretion when it was added to isolated rat pancreatic islets. These findings indicate that ghrelin may regulate islet function in an endocrine and/or paracrine manner.

Identification of regions of alpha-catenin required for desmosome organization in epithelial cells.

Alpha-catenin, a cadherin-associated protein, links cadherin/beta-catenin and cadherin/plakoglobin complexes to the actin cytoskeleton. This protein is required for the function of cadherins, cell adhesion molecules. We transfected an alpha-catenin-deficient colon carcinoma line, which cannot organize desmosomes, with a series of alpha-catenin mutant constructs. We examined the formation of desmosomes in these cells by immunofluorescence staining using anti-desmoglein and anti-desmoplakin antibodies. The results demonstrated that either the middle or the carboxy-terminal region of alpha-catenin was required for desmosome formation. Immunoblot analysis revealed that the amounts of desmoglein and desmoplakin did not differ significantly between cells that were capable of forming desmosomes and those that failed to form desmosomes. Cell surface biotinylation revealed that desmoglein was retained intracellularly in cells that could not organize desmosomes. The internal domain binds vinculin and alpha-actinin, actin-binding proteins, while the carboxy-terminal domain has the ability to bind and bundle actin filaments. These results indicate that the interaction of alpha-catenin and actin functions in the assembly of desmosomes in epithelial cells.

Inhibition by arsenic trioxide of human hepatoma cell growth.

Arsenic trioxide (As(2)O(3)) has been shown to be effective for treatment of patients with refractory or relapsed acute promyelocytic leukemia and a variety of other malignant hematopoetic disorders. We studied the effect of this agent on proliferation of human hepatoma-derived cell lines (SK-Hep-1, HepG2, and HuH7). In HuH7 cells, As(2)O(3) reduced proliferation time- and dose-dependently at 1 and 2 microM, while in SK-Hep-1 and HepG2 cells, As(2)O(3) inhibited proliferation at 2 and 4 microM respectively. Cell cycle analysis by flow cytometry showed that As(2)O(3) induced apoptosis in these hepatoma-derived cells as confirmed by appearance of sub-G(1) cells. Sensitivity of hepatoma-derived cells to As(2)O(3) was inversely related to their intracellular glutathione (GSH) and intensity of GSH synthesis. Arsenic sensitivity was restored to relatively resistant cell lines when GSH was depleted by L-buthionine sulfoximine (BSO). These results indicate that As(2)O(3) may have therapeutic potential for treatment of hepatocellular carcinoma.

Glucose-insensitivity induced by Ca(2+) toxicity in islet beta-cells and its prevention by PACAP.

The present study examined whether a sustained increase in cytosolic Ca(2+) concentration ([Ca(2+)](i)) causes glucose-insensitivity in beta-cells and whether it could be modulated by pituitary adenylate cyclase-activating polypeptide (PACAP), a pancreatic insulinotropin. Rat single beta-cells were cultured for 2 days with sustained increases in [Ca(2+)](i), followed by determination of the [Ca(2+)](i) response to glucose (8.3 mM) as monitored with fura-2. High K(+) (25 mM) produced sustained increases in [Ca(2+)](i) in beta-cells, which were inhibited by nifedipine, a Ca(2+) channel blocker. After culture with high K(+), the incidence and amplitude of [Ca(2+)](i) responses to glucose were markedly reduced. This glucose-insensitivity was prevented by the presence of nifedipine or PACAP-38 (10(-13) M and 10-9) M) in high K(+) culture. PACAP-38 attenuated high K(+)-induced [Ca(2+)](i) increases. In conclusion, sustained increases in [Ca(2+)](i) induce glucose-insensitivity (Ca(2+) toxicity in beta-cells) and it is prevented by PACAP possibly in part due to its Ca(2+)-reducing capacity.

A novel c-kit positive biphenotypic acute leukemia cell line, TMBL-1, carrying a p53 point mutation.

We established and characterized a c-kit positive cell line from the bone marrow of a patient with biphenotypic acute leukemia (BAL). The cell line, designated TMBL-1, carried a His-175 mutant p53. The immunophenotype of the primary leukemia cells at diagnosis was cytoplasmic CD3+, CD7+, CD13+, CD33-, interleukin-7 (IL-7) receptor+ and c-kit -. However, leukemia cells in relapse and TMBL-1 cells were CD33+ and c-kit +. Immunophenotypically, TMBL-1 is a BAL cell line that coexpresses T-lymphoid and myeloid markers which fulfill the criteria of the European Group for the Immunological Characterization of Leukemia. Stem cell factor (SCF), a key regulator of hematopoiesis signaling through c-kit, enhanced the proliferation of TMBL-1 cells. Direct sequencing revealed the conversion at codon 175 of the p53 gene in the TMBL-1 cells. Primary leukemia cells in relapse also carried the same point mutation but not at diagnosis. Moreover, TMBL-1 cells are sensitive to paclitaxel, which could induce p53-independent apoptosis. The biphenotypic features and p53 mutation may be associated with progression to a more malignant type. This cell line may provide new information on the role of SCF in the overlapping area between early T-lymphoid/myeloid cells, and help in the design of new therapies targeted towards p53 mutations.

Arsenic trioxide induces apoptosis in HTLV-I infected T-cell lines and fresh adult T-cell leukemia cells through CD95 or tumor necrosis factor alpha receptor independent caspase activation.

Arsenic trioxide (As2O3) has been reported to induce apoptosis in human T-cell leukemia virus type-I (HTLV-I) infected T-cell lines and fresh adult T-cell leukemia (ATL) cells and to induce G1 phase accumulation in HTLV-I infected T-cell lines. The present study aimed to clarify the pathway of As2O3-induced apoptosis in HTLV-I infected T-cell lines, MT-1 and MT-2, and fresh ATL cells separated from peripheral blood of patients with acute or chronic type ATL. Cells were treated up to 72 h at clinically tolerable concentrations of As2O3 (1-2 micromol/l) shown to be safe in patients with acute promyelocytic leukemia (APL). Activation of caspases 3, 8, and 9, loss of mitochondrial transmembrane potential and cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP) were observed during As2O3 treatment. Furthermore, prior exposure to a broad-spectrum caspase inhibitor blocked As2O3-induced apoptosis but not G1 phase accumulation. While pre-treatment with a CD95 receptor-blocking antibody (Ab) or a TNF-alpha neutralizing Ab did not show such inhibitions in these cells. In conclusion, As2O3 induces apoptosis in HTLV-I infected T-cell lines and fresh ATL cells through CD95 or TNF-alpha receptor independent caspase activation.

Augmentation of the activity of an immunotoxin, anti-Tac(Fv)-PE40KDEL, in T cell lines infected with human T cell leukemia virus type-I.

Therapy with an immunotoxin, anti-Tac(Fv)-PE38, which is a conjugate of the variable domains of an anti-Tac monoclonal antibody and Pseudomonas exotoxin, was reported to be useful for adult T cell leukemia (ATL) patients but a considerable amount of the immunotoxin is needed for the therapy and some side effects were also observed. We have previously demonstrated that an immunotoxin, anti-Tac(Fv)-PE40KDEL, showed strong cytotoxic effects on malignant cells from ATL patients. Therefore, we searched for agents that enhance the effects of the immunotoxin. PAK-200, FK-506, quinidine, cepharanthine and cyclosporine A (CsA) augmented the ability of the immunotoxin to inhibit protein synthesis in two human T cell leukemia virus type-I infected T cell lines, KUT-1 and KUT-2. CsA was the most potent agent in both the cell lines. Augmentation of the cytotoxic effect of the immunotoxin by these agents, especially CsA, may be useful in the immunotoxin therapy of ATL.

Serum levels of endogenous thrombopoietin and granulocyte-colony stimulating factor in patients with acute or lymphoma type adult T-cell leukemia during multicycle chemotherapy.

Recent multidrug chemotherapy for adult T-cell leukemia (ATL) showed improved findings, however, these protocols often induced persistent myelosuppression. Among 67 patients with acute and lymphoma type ATL treated between January 1996 and December 1998, 42 patients died during this period and showed chemotherapy-induced myelosuppression. To characterize the relation between the severity of myelosuppression and the endogenous thrombopoietin (TPO) or granulocyte-colony stimulating factor (G-CSF) levels in ATL patients, we measured these hematopoietic factors using ELISA method. Nineteen patients with acute or lymphoma type ATL and 16 healthy individuals were examined. During thrombocytopenia, the serum TPO levels were significantly higher than that of controls (P < 0.0001) and were inversely correlated with the platelet counts (r = -0.687 P < 0.001). Later in the chemotherapy cycle, severe persistent thrombocytopenia occurred and TPO levels elevated and remained at a high level approximating the TPO levels of exogenous TPO administration (0.3 microg/kg body weight). On the other hand, the serum G-CSF levels with absolute neutrophil counts (ANC) below 0.5 x 10(9)/L were significantly higher than controls (P = 0.009) and inversely correlated with ANC (r = -0.382 P = 0.0034). However, G-CSF levels in six samples obtained after 6 h of G-CSF (100-150 microg per body) administration was approximately 50-fold higher than that in the neutropenic states. These findings suggested that G-CSF can effectively reduce the severity and duration of intensified chemotherapy-induced neutropenia and higher dose exogenous TPO (higher than 0.6 microg/kg per day) therapy may be required to enhance platelet recovery after intensive chemotherapy in ATL patients.

Postpartum acute exacerbation of chronic hepatitis C with complete response to interferon-alpha.

We describe a patient with chronic hepatitis C who had severe postpartum acute exacerbation of the disease, with marked aminotransferase elevations and jaundice. The viral genotype was 2a, and the patient had a low viral load. Neither superinfection with another hepatotropic virus nor autoantibodies were evident. Markedly increased serum concentrations of T-helper (Th) 1-type cytokines and cytokine receptors, including interleukin (IL)-8, tumor necrosis factor (TNF)-alpha, soluble TNF receptor (sTNFR)-p55, sTNFR-p75, and soluble Fas antigen (sFas), as well as that of the Th 2-type cytokine, IL-10, were present. Complete biochemical and virologic response was achieved with interferon (IFN)-alpha treatment, which decreased cytokine elevations while favoring Th 1 dominance. Acute exacerbation of hepatitis C may occur when cellular immune responses are activated, as in late pregnancy and in the postpartum period. Treating such acute exacerbations immediately with IFN may be highly efficacious.

Quantitative analysis of bacterial DNA from Mycobacteria spp., Bacteroides vulgatus, and Escherichia coli in tissue samples from patients with inflammatory bowel diseases.

BACKGROUND: The etiology of inflammatory bowel diseases is unknown. Mycobacteria spp., Bacteroides vulgatus, and Escherichia coli have been suspected to be involved. The aim of the present study was to examine the possible relationship between inflammatory bowel diseases and these microbes. METHODS: We studied 45 patients; 16 with Crohn's disease, 11 with ulcerative colitis, and 18 with colon cancer as controls. We used a real-time quantitative polymerase chain reaction to detect and estimate numbers of bacterial genomes in formalin-fixed, paraffin-embedded tissue samples from the subjects. The bacteria studied were Mycobacterium tuberculosis, M. avium, M. paratuberculosis, B. vulgatus, and E. coli. Immunohistochemical staining was done to locate B. vulgatus and E. coli in tissue samples. RESULTS: The three Mycobacterium species were not detected. B. vulgatus and E. coli were detected more frequently and in greater numbers in samples from patients with inflammatory bowel diseases than in samples from control patients with colon cancer. The frequency and numbers were not related to the severity of the disease. Many bacteria of these species were found within the mucous layer, underneath erosions, in necrotic ulcer bed tissues, and in abscesses. E. coli cells were found in perivascular areas in the proper muscle layer and in germinal centers of lymph follicles. CONCLUSIONS: Our results suggest that Mycobacteria spp. are not involved in the etiology of Crohn's disease and that mucosa-associated B. vulgatus and E. coli are not a direct cause of inflammatory bowel diseases, although they may contribute to the diseases by preventing or delaying remission.

Outcome of patients with hepatitis C virus-related hepatocellular carcinoma occurring after interferon therapy.

To determine whether previous IFN therapy for chronic hepatitis C (HCV) infection influences the outcome of patients with hepatocellular carcinoma (HCC), 143 patients were enrolled in this study. Of 143 patients, 48 had received previous IFN therapy (IFN group) and the remaining 95 had not (untreated group). We estimated distant intrahepatic recurrence-free intervals and disease-specific survivals of the two groups by the Kaplan-Meier method and analyzed the difference by the log-rank test. Factors determining distant intrahepatic recurrence-free interval and disease-specific survival were studied by univariate and multivariate analysis using Cox proportional hazards regression model. The proportion of patients with single tumors was significantly higher in the IFN group (p = 0.026). The IFN group showed a significantly higher distant intrahepatic recurrence-free interval (p = 0.001) and disease-specific survival (p = 0.003). Moreover, multivariate analysis indicated that previous IFN therapy for chronic HCV infection was a significant independent factor for distant intrahepatic recurrence-free interval and disease-specific survival. These results indicate that previous IFN therapy reduces multicentric hepatocarcinogenesis of HCV-related HCC and improves the patients' survival.

Outcome of patients with hepatitis C virus-related single, small hepatocellular carcinoma.

To clarify the cumulative recurrence-free interval and survival rate with hepatitis C virus (HCV)-related single, small hepatocellular carcinoma (HCC), we studied 32 patients with surgical resection, 61 with ablation therapy and 28 with transcatheter chemoembolization (TACE). A log-rank test revealed that there were no significant differences in the recurrence-free interval (p = 0.08) and survival (p = 0.279) between the resection and the ablation groups. Univariate analysis using the Cox proportional hazards regression model showed initial treatment (p = 0.0051) was associated with recurrence-free interval. Platelet count (p = 0.009), indocianine green retention rate at 15 minutes (p = 0.003), Child-Pugh classification (p = 0.001), serum albumin level (p = 0.0012) and serum total bililubin (p = 0.015) were associated with survival. Hence patients with HCV-related single, small HCC should be treated according to their hepatic reserve.

Aspirin induces hepatoma-derived cell apoptosis via a hydrogen peroxide-dependent pathway.

Here we studied whether aspirin (ASA) has any influence on viability of human hepatoma-derived SKHep-1 cells and whether hydrogen peroxide (H(2)O(2)) has any relation with this effect. ASA inhibited SKHep-1 cell proliferation dose- and time-dependently. Intracellular H(2)O(2) increased as early as 15 min after ASA supplementation. Cellular apoptosis correlated with an increase in intracellular H(2)O(2) level. Moreover, in the presence of a catalase inhibitor-aminotriazol, ASA showed more apoptotic effect on SKHep-1 cells with increasing intracellular H(2)O(2) level. In conclusion, the present results shows that ASA induced SKHep-1 cell apoptosis has a relation with an early increase in intracellular H(2)O(2) level and catalase inhibitor synergizes to induce this process.

Pulse wave velocity as an indicator of atherosclerosis in obstructive sleep apnea syndrome patients.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular morbidity and mortality. We investigated the values of brachial-ankle pulse wave velocity as an indicator of atherosclerosis in obstructive sleep apnea syndrome patients. MATERIALS AND METHODS: Brachial-ankle pulse wave velocity (baPWV) was measured in 104 OSAS patients and 104 healthy control subjects matched for age, sex, and body mass index (BMI). BaPWV values were compared in both groups and investigated with respect to the number of risk factors for atherosclerosis, including hypertension, hypercholesterolemia, impaired glucose tolerance, smoking, and obesity. Comparisons were also made between 48 OSAS group cases and 90 control group cases free from hypertension, which has a major impact on baPWV. RESULTS: As compared to the control group, the OSAS group had significantly higher baPWV (1,645+/-349 cm/s vs 1,436+/-278 cm/s, p<0.0001), and values obtained for baPWV were significantly higher in the OSAS group than in the control group even in groups free from hypertension (1,453+/-216 cm/s vs 1,374+/-213 cm/s, p<0.05). In both groups, baPWV rose as the number of risk factors for atherosclerosis increased, but baPWV was higher in the OSAS group than in the control group even in a comparison of individuals entirely free from risk factors (1,400+/-200 cm/s vs 1,198+/-79 cm/s, p<0.05). CONCLUSION: The condition of OSAS itself is considered a possible risk factor for atherosclerosis. We believe that the usefulness of baPWV as an index of atherosclerosis merits further study in the frequently observed cases of OSAS complicated by cardiovascular disease.

c-jun mRNA expression and profilin mRNA amplification in rat alveolar macrophages exposed to volcanic ash and sulfur dioxide.

Local residents exposed to heavy falls of ash discharged by Mt. Sakurajima, an active volcano, have been reported to develop acute and chronic inflammation of the respiratory tract. The present study aimed to determine the primary cause of this inflammation using an experimental model. Wistar rats were exposed for 5 days (4 h/d) to air containing 100 mg/m3 volcanic ash (mass median aerodynamic diameter, 4.3 microm; geometric standard deviation, 1.7) with or without 1.5 ppm sulfur dioxide (SO2). The lungs were then lavaged, and mRNA was extracted from alveolar macrophages and assessed by reverse transcription-polymerase chain reaction (RT-PCR). In the lavage fluid, no change in cellularity or increase in the content of tumor necrosis factor (TNF)-alpha was detected. However, at 1 h following exposure, 80% of macrophages were seen to have phagocytosed the volcanic ash. This percentage was unchanged at 24 h after exposure. Profilin mRNA content of the macrophages was elevated, and c-jun mRNA was expressed. Alveolar macrophages exposed to volcanic ash and SO2, therefore, are likely to have some inflammatory and fibrogenic potential.

[Evaluation of endoscopic sphincter of Oddi manometry in patients with biliopancreatic diseases].

Diagnostic ability of endoscopic sphincter of oddi manometry for 112 patients with biliopancreatic diseases (including 12 patients of normal) was evaluated. The presence of abnormal high pressure was recognized in 50% of suspected sphincter of oddi dysfunction (SOD). 56% of cholecystolithiasis, 67% of cholecystocholedocholithiasis and 50% of pancreatic stones. Many patients with abdominal pain of suspected SOD or stones of biliopancreatic ducts were considered to have possibility of the complication of papillary stenosis. It was thought that endoscopic sphincter of oddi manometry was a useful method of confirming the presence of SOD.

[Clinical analysis of endoscopy negative gastroesophageal reflux disease in the elderly].

The purpose of this study was to describe the clinical analysis of endoscopy negative gastroesophageal reflux disease (EN-GERD) in the elderly. 35 elderly patients of both sexes, 60 years or older with EN-GERD, 33 elderly patients with reflux esophagitis and 41 elderly patients as control group were included in this study. All patients witnessed verbal informed consent to participate in the study. EN-GERD was defined as the patients with normal endoscopy despite of heartburn as their chief complaint and who were completely relieved with heartburn after one-week omeprazole treatment. Helicobacter pylori infection between EN-GERD, reflux esophagitis and control were 37.1%, 24.2% and 56.1%, respectively. The gastric mucosal atrophy under endoscopic findings and the serum pepsinogen I, II ratio in EN-GERD had no significant differences with control. A hiatus hernia with EN-GERD was diagnosed 37.1%, which was lower significantly than 87.9% with reflux esophagitis. The motility of the stomach using the acetaminophen method was the same in patients with EN-GERD, reflux esophagitis and control. The anxiety score of the Hospital Anxiety and Depression Scale was significantly higher in the patients with EN-GERD than in those with reflux esophagitis and control. On the other hand, the severity of reflux symptoms in the patients with EN-GERD was similar as those with reflux esophagitis. We concluded that general anxiety plays an important role in the severity of the reflux symptoms in the patients with EN-GERD. As such symptoms in EN-GERD significantly impair the quality of life, further studies of patients with EN-GERD are greatly needed.

Effectiveness of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker on atrial natriuretic peptide.

The aim of this study was to evaluate the effectiveness of an angiotensin-converting enzyne inhibitor (ACEI, quinapril) or angiotensin II receptor blocker (ARB, candesartan) on atrial natriuretic peptide (ANP) activity in rats with hypertension induced by nitric oxide (NO) inhibition. ACEI and ARB have a number of pharmacologic effects, including blood pressure reduction, myocardial preservation, and an unknown effect in the circulation. The changes in ANP in NO inhibitor-induced hypertensive rats were evaluated in order to elucidate the interaction between ANP and NO in the regulation of blood pressure. Thirty-six rats were divided into 4 groups and administered the experimental agents for 8 weeks: group CONTROL was given regular food (n=9), group N(G)-nitro-L-arginine (L-NNA) was administered L-NNA (25 mg. kg(-1). day(-1), n=9), group ACEI was administered L-NNA and quinapril (10 mg. kg(-1). day(-1), n=9), and group ARB was administered L-NNA and candesartan (10 mg. kg(-1). day(-1), n=9). Blood pressure, plasma ANP, atrial ANP, ANP mRNA, and ANP granules were measured. A significant elevation in blood pressure was observed in group L-NNA. However, there were no increases in plasma ANP (L-NNA: 138.8+/-64.4, CONTROL: 86.7+/-36.4), ANP mRNA (L-NNA: 2.2+/-1.0, CONTROL: 1.7+/-0.5) or ANP granules (L-NNA: 61.1+/-10.2, CONTROL: 64.5+/-8.5). No increase in blood pressure was seen in groups ACEI and ARB. However, plasma ANP (ACEI: 1,392.3+/-1,034.4, ARB: 1,142.8+/-667.3), ANP mRNA (ACEI: 52.8+/-29.1, ARB: 42.9+/-21.2), and ANP granules (ACEI: 122.5+/-23.4, ARB: 136.3+/-33.2) increased significantly. NO inhibitor-induced hypertension caused no changes in ANP concentrations. However, the ACEI and ARB had a direct effect on the induction of ANP secretion. The findings suggest that ANP secretion is directly effected by ACEI and ARB, which seems to play a key role in lowering blood pressure, relieving heart failure symptoms, and preserving the myocardium.