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1.
Aliment Pharmacol Ther ; 38(7): 741-51, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23957734

ABSTRACT

BACKGROUND: Placebo-controlled studies in maintaining remission of symptomatic uncomplicated diverticular disease (SUDD) of the colon are lacking. AIM: To assess the effectiveness of mesalazine and/or probiotics in maintaining remission in SUDD. METHODS: A multicentre, double-blind, placebo-controlled study was conducted. Two hundred and ten patients were randomly enrolled in a double-blind fashion in four groups: Group M (active mesalazine 1.6 g/day plus Lactobacillus casei subsp. DG placebo), Group L (active Lactobacillus casei subsp. DG 24 billion/day plus mesalazine placebo), Group LM (active Lactobacillus casei subsp. DG 24 billion/day plus active mesalazine), Group P (Lactobacillus casei subsp. DG placebo plus mesalazine placebo). Patients received treatment for 10 days/month for 12 months. Recurrence of SUDD was defined as the reappearance of abdominal pain during follow-up, scored as ≥5 (0: best; 10: worst) for at least 24 consecutive hours. RESULTS: Recurrence of SUDD occurred in no (0%) patient in group LM, in 7 (13.7%) patients in group M, in 8 (14.5%) patients in group L and in 23 (46.0%) patients in group P (LM group vs. M group, P = 0.015; LM group vs. L group, P = 0.011; LM group vs. P group, P = 0.000; M group vs. P group, P = 0.000; L group vs. P group, P = 0.000). Acute diverticulitis occurred in six group P cases and in one group L case (P = 0.003). CONCLUSION: Both cyclic mesalazine and Lactobacillus casei subsp. DG treatments, particularly when given in combination, appear to be better than placebo for maintaining remission of symptomatic uncomplicated diverticular disease. (ClinicalTrials.gov: NCT01534754).


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Diverticulum, Colon/drug therapy , Mesalamine/therapeutic use , Probiotics/therapeutic use , Abdominal Pain/etiology , Aged , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Diverticulum, Colon/pathology , Double-Blind Method , Female , Follow-Up Studies , Humans , Lactobacillus , Male , Mesalamine/administration & dosage , Middle Aged , Secondary Prevention , Treatment Outcome
2.
Virology ; 373(1): 72-84, 2008 Mar 30.
Article in English | MEDLINE | ID: mdl-18155743

ABSTRACT

Vaccine immunogens derived from the envelope glycoproteins of the human immunodeficiency virus type 1 (HIV-1) that elicit broad neutralizing antibodies remain an elusive goal. The highly conserved 30 amino-acid membrane proximal external region (MPER) of HIV gp41 contains the hydrophobic epitopes for two rare HIV-1 broad cross-reactive neutralizing antibodies, 2F5 and 4E10. Both these antibodies possess relatively hydrophobic HCDR3 loops and demonstrate enhanced binding to their epitopes in the context of the native gp160 precursor envelope glycoprotein by the intimate juxtaposition of a lipid membrane. The hepatitis B surface antigen (HBsAg) S1 protein forms nanoparticles that can be utilized both as an immunogenic array of the MPER and to provide the lipid environment needed for enhanced 2F5 and 4E10 binding. We show that recombinant HBsAg particles with MPER (HBsAg-MPER) appended at the C-terminus of the S1 protein are recognized by 2F5 and 4E10 with high affinity compared to positioning the MPER at the N-terminus or the extracellular loop (ECL) of S1. Addition of C-terminal hydrophobic residues derived from the HIV-1 Env transmembrane region further enhances recognition of the MPER by both 2F5 and 4E10. Delipidation of the HBsAg-MPER particles decreases 2F5 and 4E10 binding and subsequent reconstitution with synthetic lipids restores optimal binding. Inoculation of the particles into small animals raised cross-reactive antibodies that recognize both the MPER and HIV-1 gp160 envelope glycoproteins expressed on the cell surface; however, no neutralizing activity could be detected. Prime:Boost immunization of the HBsAg-MPER particles in sequence with HIV envelope glycoprotein proteoliposomes (Env-PLs) did not raise neutralizing antibodies that could be mapped to the MPER region. However, the Env-PLs did raise anti-Env antibodies that had the ability to neutralize selected HIV-1 isolates. The first generation HBsAg-MPER particles represent a unique means to present HIV-1 envelope glycoprotein neutralizing determinants to the immune system.


Subject(s)
HIV Envelope Protein gp41/chemistry , HIV Envelope Protein gp41/immunology , Hepatitis B Surface Antigens/immunology , Recombinant Fusion Proteins/immunology , AIDS Vaccines/administration & dosage , AIDS Vaccines/immunology , Amino Acid Sequence , Animals , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , HIV Antibodies/immunology , HIV Envelope Protein gp41/genetics , HIV Envelope Protein gp41/metabolism , HIV-1/immunology , Hepatitis B Surface Antigens/genetics , Hepatitis B Surface Antigens/metabolism , Humans , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Neutralization Tests , Rabbits , Recombinant Fusion Proteins/administration & dosage , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Virion/genetics , Virion/metabolism
3.
Hepatol Res ; 36(3): 176-81, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16965938

ABSTRACT

BACKGROUND/AIM: Hepatic cirrhosis is a frequent reason for ordinary hospital admission (OA). The RING study collected hospital discharge files (HDF) from Italian hospital gastroenterology units (IGU). This caselist provides a broad picture of the patients admitted for this pathology. MATERIAL/METHODS: More than 50,000 HDF for OA were collected between 2001 and 2004 from 26 IGU. RESULTS: Eight thousand four hundred and eighty-seven HDF (16%) had a diagnosis of hepatic cirrhosis; Child-Pugh classes were 20.2% A, 34.8% B and 45.0% C. Patients' mean age was 63.7+/-12.1 years and 62.5% were male. A 61.1% of the cirrhosis cases had ascites, 29.9% portal-systemic encephalopathy, 29.2% hepatocellular carcinoma (HCC), 10% bleeding varices, 3.0% hepatorenal syndrome (HRS). Mortality for OA for cirrhosis was 5.7% versus 2.6% for other diagnoses. The proportion varied with the severity of the cirrhosis: 0% for Child A, 1.1% B, 10.5% C. Mortality was significantly associated with: Child-Pugh at admission (odds ratio: OR 9.2), HRS (OR 11.7), bleeding varices (OR 2.2), HCC (OR 1.8). CONCLUSIONS: Hepatic cirrhosis was found in 16% of the OA to IGU and mortality was double the rate for all the other pathologies in the same wards. Child-Pugh is a useful prognostic tool, higher classes implying a greater risk of death. HRS and bleeding varices were the complications with most influence on in-hospital mortality.

4.
J Viral Hepat ; 11(6): 536-42, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15500554

ABSTRACT

Expert consensus recommends liver biopsy before therapy for chronic hepatitis C. A cost effectiveness analysis suggested that the best strategy in the management of patients was to treat without biopsy. We compared therapy in patients who did, or did not undergo biopsy. Hepatitis C virus (HCV)-positive patients (78) who did not agree to (n = 57) or with contraindications to liver biopsy (n = 21) (group A) were matched for age, sex and genotype with those who consented (group B). Before therapy (interferon/ribavirin for 12 months), a clinical diagnosis of chronic hepatitis, on the basis of standard biochemical and ultrasonographic parameters. The two groups showed similar baseline characteristics. A noninvasive, diagnosis of chronic hepatitis was made in 75.6% of group A, and in 83.3% of group B (P = 0.26). Concordance between clinical and histological diagnosis in group B amounted to 91%. End-of-therapy virological response was 52.6% in group A, and 57.7% in group B (P = 0.63). Sustained virological response was 41.0% [95% confidence interval (CI) 30.1-51.9] and 43.6% (95% CI 32.6-54.6) in the two groups (P = 0.87). Predictors of sustained response were noninvasive diagnosis of chronic hepatitis (P = 0.006), lack of portal hypertension (P = 0.037), platelets >10(5)/mm3 (P = 0.007), prothrombin >70% (P = 0.02), and genotype 2 or 3 (P < 0.0001). At multivariate analysis, genotype (P < 0.0001) and platelets (P = 0.004) maintained their predictive power. In most patients with HCV infection, virological clearance after therapy can be achieved irrespective of whatever a liver biopsy might show.


Subject(s)
Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/pathology , Interferons/therapeutic use , Liver/pathology , Ribavirin/therapeutic use , Adult , Biopsy , Drug Therapy, Combination , Female , Hepacivirus , Hepatitis C, Chronic/virology , Humans , Male , Middle Aged , Treatment Outcome
5.
J Virol ; 74(18): 8444-51, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10954544

ABSTRACT

Interaction of erythropoietin (Epo) with its cell surface receptor activates signal transduction pathways which result in the proliferation and differentiation of erythroid cells. Infection of erythroid cells with the Friend spleen focus-forming virus (SFFV) leads to the interaction of the viral envelope glycoprotein with the Epo receptor and renders these cells Epo independent. We previously reported that SFFV induces Epo independence by constitutively activating components of several Epo signal transduction pathways, including the Jak-Stat and the Raf-1/mitogen-activated protein kinase (MAPK) pathways. To further evaluate the mechanism by which SFFV activates the Raf-1/MAPK pathway, we investigated the effects of SFFV on upstream components of this pathway, and our results indicate that SFFV activates Shc and Grb2 and that this leads to Ras activation. While studies with a dominant-negative Ras indicated that Ras was required for Epo-induced proliferation of normal erythroid cells, the Epo-independent growth of SFFV-infected cells can still occur in the absence of Ras, although at reduced levels. In contrast, protein kinase C (PKC) was shown to be required for the Epo-independent proliferation of SFFV-infected cells. Further studies indicated that PKC, which is thought to be involved in the activation of both Raf-1 and MAPK, was required only for the activation of MAPK, not Raf-1, in SFFV-infected cells. Our results indicate that Ras and PKC define two distinct signals converging on MAPK in both Epo-stimulated and SFFV-infected erythroid cells and that activation of only PKC is sufficient for the Epo-independent proliferation of SFFV-infected cells.


Subject(s)
Adaptor Proteins, Signal Transducing , Adaptor Proteins, Vesicular Transport , Erythroblasts/metabolism , Erythropoietin/metabolism , Guanosine Triphosphate/metabolism , Protein Kinase C/metabolism , Spleen Focus-Forming Viruses/metabolism , Sulfonamides , ras Proteins/metabolism , Blotting, Western , Cell Division , Enzyme Inhibitors/pharmacology , ErbB Receptors/metabolism , Erythroblasts/virology , GRB2 Adaptor Protein , Humans , Indoles/pharmacology , Isoquinolines/pharmacology , Maleimides/pharmacology , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation , Protein Binding , Protein Kinase C/antagonists & inhibitors , Proteins/metabolism , Proto-Oncogene Proteins c-raf/metabolism , Shc Signaling Adaptor Proteins , Signal Transduction , Src Homology 2 Domain-Containing, Transforming Protein 1 , Staurosporine/pharmacology , Transfection , Tumor Cells, Cultured
6.
J Biol Chem ; 275(33): 25292-8, 2000 Aug 18.
Article in English | MEDLINE | ID: mdl-10842186

ABSTRACT

In this study, regulation of transcription factor NF-E2 was examined in differentiating erythroid and myeloid cells, and the impact of raising NF-E2 concentrations within these cell types was assessed. NF-E2 was expressed in the J2E erythroid cell line, but the levels increased only marginally during erythropoietin-induced differentiation. In contrast, rare myeloid variants of J2E cells did not express NF-E2. Although NF-E2 was present in M1 monoblastoid cells, it was undetectable as these cells matured into macrophages. Compared with erythroid cells, transcription of the NF-E2 gene was reduced, and the half-life of the mRNA was significantly shorter in monocytoid cells. Ectopic expression of NF-E2 had a profound impact upon the J2E cells; morphologically mature erythroid cells spontaneously emerged in culture, but the cells failed to synthesize hemoglobin, even in the presence of erythropoietin. Although proliferation and viability increased in the NF-E2-transfected J2E cells, their responsiveness to erythropoietin was severely diminished. Strikingly, increasing the expression of NF-E2 in M1 cells produced sublines that contained erythroid or immature megakaryocytic cells. Finally, overexpression of NF-E2 in primary hemopoietic progenitors from fetal liver increased erythroid colony formation in the absence of erythropoietin. These data demonstrate that elevated NF-E2 (i) had a dominant effect on the phenotype and maturation of J2E erythroid cells, (ii) was able to reprogram the M1 monocytoid line, and (iii) promoted the development of erythroid colonies by normal progenitors.


Subject(s)
DNA-Binding Proteins/metabolism , Erythroid Precursor Cells/cytology , Erythroid Precursor Cells/metabolism , Leukemia, Myeloid, Acute/metabolism , Transcription Factors/metabolism , Blotting, Northern , Blotting, Western , Cell Division , Cell Line , Cell Nucleus/metabolism , Cell Survival , Erythroid-Specific DNA-Binding Factors , Flow Cytometry , Growth Inhibitors/metabolism , Hemoglobins/biosynthesis , Humans , Interleukin-6/metabolism , Leukemia Inhibitory Factor , Liver/embryology , Lymphokines/metabolism , Macrophages/metabolism , Megakaryocytes/metabolism , NF-E2 Transcription Factor , NF-E2 Transcription Factor, p45 Subunit , Phenotype , RNA, Messenger/metabolism , Retroviridae/metabolism , Time Factors , Tumor Cells, Cultured
7.
Aliment Pharmacol Ther ; 12(10): 997-1001, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9798805

ABSTRACT

BACKGROUND: A combination of an antisecretory agent with two antibiotics is considered the 'gold standard' for Helicobacter pylori eradication. OBJECTIVES: To compare the eradication rates and the safety profile of two short-term triple therapies containing lansoprazole (L) or ranitidine bismuth citrate (RBC) as antisecretory agents. METHODS: One hundred and twelve H. pylori-positive patients either with peptic ulcer (56 duodenal ulcers: 25 active and 31 with a history of ulcer; 13 gastric ulcers: nine active and four with a history of ulcer) or gastritis (43) were included in an open, randomized, controlled trial. H. pylori infection was initially detected by CLO-test and histology on antral and corpus biopsies. H. pylori-positive patients were randomized to receive L plus clarithromycin (C) 250 mg b.d. plus tinidazole (T) 500 mg b.d. (LCT) or RBC plus C 250 mg b.d. and T 500 mg b.d. for 7 days (RbcCT). L or RBC were administered for a further 3 weeks in patients with active peptic ulcers. A second endoscopy was performed at least 6 weeks after the end of therapy for the assessment of H. pylori infection by CLO-test and histology. Eradication was assumed if all the tests were negative for H. pylori. RESULTS: Forty-eight patients in the LCT group and 4 5 in the RbcCT group were assessed for H. pylori eradication. The eradication rates, according to intention-to-treat (ITT) and per protocol (PP) analyses were, respectively, 76.8% and 89.5% for the LCT group, and 73.2% and 91.1% for the RbcCT group. No statistically significant difference in eradication rates was found between the two groups by Mantel-Haenszel test. All peptic ulcers were healed. In patients in whom H. pylori had been eradicated, the severity of gastritis was significantly reduced. Side-effects were rare. One patient in the LCT group and two in the RbcCT group were withdrawn because of adverse events. CONCLUSION: Short-term triple therapy with either lansoprazole or RBC is equally effective and well tolerated.


Subject(s)
Helicobacter Infections/drug therapy , Helicobacter pylori , Omeprazole/analogs & derivatives , Ranitidine/therapeutic use , 2-Pyridinylmethylsulfinylbenzimidazoles , Adolescent , Adult , Aged , Anti-Ulcer Agents/therapeutic use , Clarithromycin/administration & dosage , Drug Therapy, Combination/therapeutic use , Female , Humans , Lansoprazole , Male , Middle Aged , Omeprazole/adverse effects , Omeprazole/therapeutic use , Peptic Ulcer/microbiology , Ranitidine/adverse effects , Time Factors , Tinidazole/administration & dosage , Tinidazole/therapeutic use
8.
J Biol Chem ; 273(37): 23793-8, 1998 Sep 11.
Article in English | MEDLINE | ID: mdl-9726989

ABSTRACT

The erythroid Krüppel-like factor (EKLF) is essential for the transcription of betamaj globin in erythroid cells. We show here that RNA for this transcription factor did not alter during erythropoietin-induced differentiation of J2E cells; however, EKLF protein content decreased and was inversely related to globin production. This unexpected result was also observed during chemically induced maturation of two murine erythroleukemia cell lines. To explore the role of EKLF in erythroid terminal differentiation, an antisense EKLF construct was introduced into J2E cells. As a consequence EKLF RNA and protein levels fell by approximately 80%, and the cells were unable to manufacture hemoglobin in response to erythropoietin. The failure to produce hemoglobin was due to reduced transcription of not only globin genes but also key heme enzyme genes. However, numerous other genes, including several erythroid transcription factors, were unaffected by the decrease in EKLF. Although hemoglobin synthesis was severely impaired with depleted EKLF levels, morphological maturation in response to erythropoietin continued normally. Moreover, erythropoietin-induced proliferation and viability were unaffected by the decrease in EKLF levels. We conclude that EKLF affects a specific set of genes, which regulates hemoglobin production and has no obvious effect on morphological changes, cell division, or viability in response to erythropoietin.


Subject(s)
DNA-Binding Proteins/metabolism , Erythropoietin/pharmacology , Globins/genetics , Hemoglobins/genetics , Transcription Factors/metabolism , Transcription, Genetic , Animals , Cell Differentiation , Cell Division , Cell Line, Transformed , Cell Nucleus/metabolism , Cell Survival , DNA, Antisense , Globins/biosynthesis , Hemoglobins/biosynthesis , Humans , Kruppel-Like Transcription Factors , Leukemia, Erythroblastic, Acute , Mice , Oncogenes , Recombinant Proteins , Signal Transduction , Tumor Cells, Cultured , Zinc Fingers
9.
Aliment Pharmacol Ther ; 12(6): 533-7, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9678812

ABSTRACT

BACKGROUND: This multicentre, randomized study was designed to assess the clinical efficacy, safety and tolerability of three novel 7-day triple therapies containing ranitidine bismuth citrate (RBC) and two antibiotics. METHODS: We studied patients with non-ulcer dyspepsia and gastritis who were randomly assigned to one of three treatment regimens given for 7 days in a b.d. dosing schedule: RBC 400 mg plus clarithromycin 250 mg and tinidazole 500 mg (RBCCT): RBC 400 mg plus clarithromycin 500 mg and amoxycillin 1 g (RBCCA); RBC 400 mg plus tinidazole 500 mg and amoxycillin 1 g (RBCTA). H. pylori status was determined by CLO-test, histology and 13C-urea breath test. A repeat breath test was performed at least 28 days after completion of therapy to assess eradication. RESULTS: One hundred and fifty-seven patients were eligible for intention-to-treat analysis (ITT) and 140 patients completed the study and returned for assessment of eradication. Intention-to-treat cure rates were 78% with RBCCT, 71% with RBCCA and 61% with RBCTA. An all-patients-treated analysis (APT), performed on evaluable patients, demonstrated eradication rates of 85% with RBCCT, 81% with RBCCA and 70% with RBCTA. No statistically significant difference was found between treatment groups. Twenty-four patients experienced side-effects, but in only seven cases was treatment discontinued due to adverse events. CONCLUSIONS: A 7-day course of RBC, clarithromycin and either tinidazole or amoxycillin provides a good rate of H. pylori eradication. Three novel RBC-based triple therapies proved to be safe and well tolerated, with discontinuations due to side-effects occurring in less than 5% of cases.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Anti-Ulcer Agents/therapeutic use , Bismuth/therapeutic use , Helicobacter Infections/drug therapy , Helicobacter pylori , Ranitidine/analogs & derivatives , Adolescent , Adult , Aged , Aged, 80 and over , Amoxicillin/administration & dosage , Amoxicillin/therapeutic use , Anti-Bacterial Agents/administration & dosage , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/adverse effects , Bismuth/administration & dosage , Bismuth/adverse effects , Clarithromycin/administration & dosage , Clarithromycin/therapeutic use , Double-Blind Method , Drug Therapy, Combination , Dyspepsia/drug therapy , Dyspepsia/microbiology , Female , Gastritis/drug therapy , Gastritis/microbiology , Gastroscopy , Helicobacter Infections/microbiology , Humans , Male , Middle Aged , Penicillins/administration & dosage , Penicillins/therapeutic use , Ranitidine/administration & dosage , Ranitidine/adverse effects , Ranitidine/therapeutic use , Tinidazole/administration & dosage , Tinidazole/therapeutic use
10.
Aliment Pharmacol Ther ; 12(5): 447-51, 1998 May.
Article in English | MEDLINE | ID: mdl-9663724

ABSTRACT

BACKGROUND: No clinical study has been performed to-date to evaluate the efficacy of the dual therapy of ranitidine bismuth citrate (RBC) plus clarithromycin (C) 500 mg b.d. given for 7 days for the eradication of H. pylori. AIM: To assess the eradication rates achieved by treatment with RBC 400 mg b.d. for 28 days combined with clarithromycin 500 mg b.d. for 7 days in H. pylori-positive duodenal ulcer patients. METHODS: One hundred and twelve H. pylori-positive patients with endoscopically proven active duodenal ulcer were included in a multicentre, open, randomized trial. H. pylori infection was initially detected by CLO-test and histology on antral and corpus biopsies, and by 13C-urea breath test (UBT). Patients were included if at least two of the tests were positive for H. pylori infection. Patients were randomized to receive RBC 400 mg b.d. for 4 weeks combined with clarithromycin 500 mg b.d. for the first 7 days (Group A) or 14 days (Group B). A second endoscopy was performed at least 28 days after the end of therapy for the assessment of ulcer healing and H. pylori infection. Eradication was assumed if all the tests (CLO-test, histology and UBT) were negative for H. pylori. RESULTS: Fifty patients in Group A and 55 in Group B were assessed for H. pylori eradication and ulcer healing. The eradication rates according to intention-to-treat analysis were 75% in Group A and 80% in Group B. Considering only those patients with evaluable data at least 28 days after the end of therapy, H. pylori eradication was achieved in 84% and 82% in Group A and B, respectively. No statistically significant difference in eradication was found between the two groups by Mantel-Haenszel test. Only one patient, in Group A, was withdrawn because of adverse events (epigastric pain and pruritus).


Subject(s)
Anti-Bacterial Agents/therapeutic use , Anti-Ulcer Agents/therapeutic use , Bismuth/therapeutic use , Clarithromycin/therapeutic use , Duodenal Ulcer/drug therapy , Helicobacter Infections/drug therapy , Helicobacter pylori , Ranitidine/analogs & derivatives , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/adverse effects , Bismuth/administration & dosage , Bismuth/adverse effects , Clarithromycin/administration & dosage , Clarithromycin/adverse effects , Drug Therapy, Combination , Duodenal Ulcer/microbiology , Female , Helicobacter Infections/microbiology , Humans , Male , Middle Aged , Ranitidine/administration & dosage , Ranitidine/adverse effects , Ranitidine/therapeutic use
11.
Eur J Biochem ; 249(1): 77-84, 1997 Oct 01.
Article in English | MEDLINE | ID: mdl-9363756

ABSTRACT

The regulation of transferrin-receptor synthesis was studied in J2E erythroid cells induced to differentiate with erythropoietin. Nuclear run-on assays demonstrated that transcription of the transferrin-receptor gene rose markedly after erythropoietin treatment. In addition, transferrin-receptor mRNA was stabilised and this was associated with an increase in the activity of the RNA-binding protein IRP (iron regulatory protein). As a result of increased transcription and mRNA stabilisation, steady-state RNA levels increased 10-20-fold. However, despite these large increases in mRNA, translation only doubled; consequently, modest increases in total protein and surface transferrin receptors were observed. Moreover, this rise in transferrin receptors was transient, and correlated with a burst of proliferation shortly after erythropoietin treatment. The expected inverse relationship between transferrin receptors and ferritin did not occur during J2E maturation as translation of both ferritin subunits increased when transferrin-receptor mRNA levels rose. Analysis of mutant J2E clones incapable of synthesising haemoglobin revealed that surface transferrin-receptor levels were only 15-25% that of the parental erythroid line. We propose that the surface expression of transferrin receptors in J2E cells is governed by three factors: basal levels essential for normal growth in culture; elevated levels needed for haemoglobin synthesis; and a transient erythropoietin-induced increase that is required for the final burst of proliferation. It was concluded that the regulation of transferrin-receptor production in erythropoietin-stimulated J2E cells is complex and that there are several sites of control.


Subject(s)
Erythroblasts/metabolism , Receptors, Transferrin/metabolism , Animals , Cell Differentiation/drug effects , Cell Line , Erythroblasts/cytology , Erythroblasts/drug effects , Erythropoietin/pharmacology , Ferritins/genetics , Mice , Mutation , Protein Biosynthesis/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Transferrin/genetics , Transcription, Genetic/drug effects
12.
Aliment Pharmacol Ther ; 10(5): 829-31, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8899094

ABSTRACT

AIM: To compare the results of two short triple-therapy regimens, different only in the antisecretory drugs used, in patients with active duodenal ulcer and Helicobacter pylori infection. METHODS: All patients received a combination of clarithromycin 250 mg b.d. and tinidazole 500 mg b.d. for 1 week, in addition to an antisecretory drug: omeprazole 20 mg (50 patients) or ranitidine 300 mg (50 patients) twice daily for 1 week, followed by a single daily dose for a further 3 weeks. Upper gastrointestinal endoscopy, with rapid urease test and histological examination of antral and corpus biopsies, was performed prior to the treatment and at least 2 months after the discontinuation of the antisecretory therapy. RESULTS: Duodenal ulcer healing was documented in all patients at the endoscopic examination after therapy. H. pylori eradication was achieved in 46 of 50 patients (92%, 95% CI = 85-99%) in the omeprazole group and in 43 of 50 patients (86%, 95% CI = 76-96%) in the ranitidine group: the difference is not significant. CONCLUSION: Omeprazole or ranitidine, in combination with clarithromycin and tinidazole, are equally effective in the eradication of H. pylori infection and healing of duodenal ulcers.


Subject(s)
Anti-Ulcer Agents/therapeutic use , Duodenal Ulcer/drug therapy , Helicobacter Infections/drug therapy , Omeprazole/therapeutic use , Ranitidine/therapeutic use , Adult , Aged , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/pharmacology , Antitrichomonal Agents/administration & dosage , Antitrichomonal Agents/pharmacology , Antitrichomonal Agents/therapeutic use , Chi-Square Distribution , Clarithromycin/administration & dosage , Clarithromycin/pharmacology , Clarithromycin/therapeutic use , Female , Helicobacter pylori/drug effects , Humans , Male , Middle Aged , Omeprazole/administration & dosage , Omeprazole/pharmacology , Prospective Studies , Ranitidine/administration & dosage , Ranitidine/pharmacology , Tinidazole/administration & dosage , Tinidazole/pharmacology , Tinidazole/therapeutic use
13.
Eur J Biochem ; 230(2): 475-80, 1995 Jun 01.
Article in English | MEDLINE | ID: mdl-7607218

ABSTRACT

The expression of the major erythroid DNA-binding protein GATA-1 was studied during erythropoietin and chemically induced erythroid differentiation of J2E and murine erythroleukemia (MEL) cells. An increase in GATA-1 mRNA levels was observed shortly after hormonal stimulation of J2E cells, due to increased transcription and not stabilization of the short-lived transcripts. Concomitantly, an increase in protein capable of binding to the GATA motif was detected. Premature removal of erythropoietin from culture resulted in submaximal GATA-1, globin, and hemoglobin production. In contrast, differentiation of J2E cells initiated by sodium butyrate resulted in a sudden depletion of GATA-1 transcripts. Similarly, dimethyl sulphoxide induction of MEL cells produced a transient decrease in GATA-1 mRNA. Surprisingly, these decreases in mRNA were not reflected in alterations to GATA-1 protein content, or the ability of the transcription factor to bind DNA. We concluded from this study that the sequence of events initiated by erythropoietin was not followed during chemical stimulation of erythroid differentiation.


Subject(s)
DNA-Binding Proteins/metabolism , Erythrocytes/drug effects , Erythropoietin/pharmacology , Transcription Factors/metabolism , Animals , Base Sequence , DNA-Binding Proteins/genetics , Dimethyl Sulfoxide/pharmacology , Erythrocytes/cytology , Erythrocytes/metabolism , Erythroid-Specific DNA-Binding Factors , Erythropoiesis/drug effects , GATA1 Transcription Factor , Mice , Molecular Sequence Data , Oligodeoxyribonucleotides , RNA, Messenger/genetics , Transcription Factors/genetics , Transcription, Genetic/drug effects , Tumor Cells, Cultured
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