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1.
Oncogenesis ; 5(8): e255, 2016 Aug 15.
Article in English | MEDLINE | ID: mdl-27526109

ABSTRACT

Stimulating tumor cell senescence and apoptosis are proven methods for therapeutically combating cancer. However, senescence and apoptosis are conventionally viewed as parallel, not sequential, processes. We have discovered that the metastasis-promoting phosphatase, PRL-3, is transcriptionally regulated by the NF-ĸB pathway in triple-negative breast cancer (TNBC) cells, and that PRL-3 knockdown elicits an autocrine tumor necrosis factor receptor 1 (TNF-R1) feedback loop that results in TNBC cell senescence followed by apoptosis. Knockdown of PRL-3 leads to rapid G1 cell cycle arrest and induction of a strong TNFα cytokine response that promotes a period of cellular senescence through TNF-R1-mediated activation of NF-ĸB. Senescent PRL-3 knockdown cells subsequently underwent apoptosis as a result of increased TNF-R1 signaling through the TNFα-associated extrinsic death pathway, shunting signaling away from the NF-ĸB cascade. These data suggest that TNF-R1 signaling dynamically re-programs after PRL-3 knockdown, from sustaining cell senescence through NF-ĸB to promoting apoptosis through TNF-R1 internalization and caspase-8 activation. The molecular mechanisms that determine the survival-death balance of TNF-R1 signaling are poorly understood, despite the fact that TNF-R1 has been extensively studied. Our results describe PRL-3 knockdown as a novel survival-death balance modifier of the TNF-R1 pathway, and show that senescent TNBC tumor cells can be sensitized to undergo apoptosis in a sequential manner.

2.
Br J Haematol ; 143(3): 307-20, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19004076

ABSTRACT

Since the discovery of the JAK2 V617F mutation, the clinical and pathological consequences of this acquired defect have been extensively investigated to determine whether its presence characterises a distinct subgroup of myeloproliferative disorders (MPD). MPD management remains highly dependent on the patient's thrombotic risk. Whether the presence of the JAK2 V617F mutation modifies the thrombotic risk is currently contentious, although there is increasing clinical evidence to suggest that the mutation may be variably associated with thrombosis. These observations are further supported by laboratory parameters which suggest that the JAK2 V617F mutation may confer increased activation of leucocytes and platelets in MPD. The role of screening for the JAK2 V617F mutation in patients presenting with thrombosis without overt MPD is unclear, but appears justified in cases of idiopathic splanchnic vein thrombosis.


Subject(s)
Janus Kinase 2/genetics , Mutation , Thrombosis/genetics , Genetic Predisposition to Disease , Humans , Myeloproliferative Disorders/complications , Myeloproliferative Disorders/genetics , Risk Factors , Thrombosis/etiology , Venous Thrombosis/etiology , Venous Thrombosis/genetics
3.
Br J Haematol ; 142(3): 453-6, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18510687

ABSTRACT

There is no evidence-based approach for the optimal management of peri-delivery anticoagulation in women receiving therapeutic dose of low-molecular weight heparin (LMWH) during pregnancy. Nevertheless, the maintenance of anticoagulation for the maximal period peri-delivery appears appropriate in women considered to be at high risk of venous or arterial thromboembolism. We developed a regimen based on fixed thromboprophylactic dose of unfractionated heparin (UFH) peri-delivery and undertook an audit to evaluate the use and feasibility of this approach and any adverse events. Fixed intravenous thromboprophylactic dose of UFH (15,000 units/24 h) was commenced on the evening prior to a planned delivery [induction of labour or elective caesarean section (CS)], stopped 4 h predelivery and restarted 2-6 h postdelivery. Compliance was good with 32/38 consecutive deliveries managed according to the regimen. There were no cases of postpartum haemorrhage and no thrombosis associated with these 32 deliveries. Twenty-one patients were delivered by CS (11 elective) and eight patients received epidural/spinal anaesthesia without complication. In conclusion, the fixed thromboprophylactic dose UFH regimen provided maintenance of anticoagulation except for a matter of hours without excessive bleeding risk (conducive to neuroaxial anaesthesia) and was simple, flexible and acceptable to staff and patients.


Subject(s)
Anticoagulants/therapeutic use , Heparin/therapeutic use , Labor, Obstetric , Medical Audit/methods , Thromboembolism/prevention & control , Adult , Anesthesia, Obstetrical , Anesthesia, Spinal , Cesarean Section , Female , Heparin, Low-Molecular-Weight/administration & dosage , Humans , Incidence , Labor, Induced , Patient Compliance , Postpartum Hemorrhage/prevention & control , Pregnancy , Retrospective Studies , Treatment Outcome , Young Adult
4.
Oncogene ; 26(27): 3952-62, 2007 Jun 07.
Article in English | MEDLINE | ID: mdl-17213814

ABSTRACT

Fenretinide (4-HPR) is a synthetic retinoid with antitumor activity, which induces apoptosis in cancer cell lines of different histotypes. To identify genes contributing to its apoptotic activity in ovarian cancer cells, we monitored, by cDNA arrays, gene expression changes after 4-HPR exposure in A2780, a human ovarian carcinoma cell line sensitive to the retinoid. Among the differentially expressed transcripts, PLAcental Bone morphogenetic protein (PLAB), a proapoptotic gene, was the most highly induced. In a panel of ovarian carcinoma cell lines with different 4-HPR sensitivities, PLAB upregulation was associated with cellular response to 4-HPR, its overexpression increased basal apoptosis and its silencing by small interfering RNA decreased the ability of 4-HPR to induce apoptosis. PLAB induction by 4-HPR was p53- and EGR-1 independent and was regulated, at least in part, by increased stability of PLAB mRNA. PLAB up-modulation by 4-HPR also occurred in vivo: in ascitic cells collected from patients with ovarian cancer before and after 4-HPR treatment, PLAB was upmodulated in 2/4 patients. Our results in certain ovarian cancer cell lines indicate a role for PLAB as a mediator of 4-HPR-induced apoptosis. The correlation of increased PLAB in vivo with antitumor activity remains to be established.


Subject(s)
Apoptosis/drug effects , Bone Morphogenetic Proteins/genetics , Fenretinide/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Ovarian Neoplasms/genetics , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Blotting, Western , Bone Morphogenetic Proteins/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Female , Fenretinide/therapeutic use , Gene Expression Profiling , Growth Differentiation Factor 15 , Humans , Oligonucleotide Array Sequence Analysis , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/pathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Retinoids/chemistry , Retinoids/pharmacology , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Transcription, Genetic/drug effects , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
5.
Clin Exp Allergy ; 37(1): 72-82, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17210044

ABSTRACT

BACKGROUND: Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory-tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. OBJECTIVE: To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. METHODS: Sputum cells were induced from steroid-naïve, allergen-challenged and allergen-naïve subjects (atopic asthmatics, atopic non-asthmatics and non-atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. RESULTS: hRTDC stained HLA-DR(+) (negative for markers of other cell lineages) were predominantly myeloid and comprised approximately 0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4(+) naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC-dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05-P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c(-)CD123(high) hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. CONCLUSION: Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies.


Subject(s)
Allergens , Antigens, CD1/immunology , Asthma/immunology , Respiratory System/immunology , Up-Regulation , Administration, Inhalation , Adult , Aged , Allergens/immunology , Analysis of Variance , Biomarkers , CD11c Antigen/analysis , CD40 Antigens/analysis , Case-Control Studies , Dendritic Cells/immunology , Dendritic Cells/physiology , Endocytosis , Female , Flow Cytometry , Humans , Lymphocyte Activation , Male , Microscopy, Immunoelectron , Middle Aged , Receptor, Platelet-Derived Growth Factor alpha/analysis , Skin Tests , Sputum/immunology , Statistics, Nonparametric
7.
J Gastroenterol Hepatol ; 15(3): 254-6, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10764024

ABSTRACT

BACKGROUND AND METHODS: A total antibody latex serology test was compared with enzyme immunoassay serology after treatment for Helicobacter pylori infection in 22 patients. RESULTS: Nineteen patients were cured of infection, but only nine (47%) were negative by the latex test after 6 months. However a significant decline in immunoglobulin (Ig)G was seen in 90% of the cured patients. CONCLUSIONS: Although the latex test is suitable for initial diagnosis of H. pylori infection, it is not suitable for monitoring treatment success. A decline in IgG of more than 40% correlates well with successful eradication of H. pylori.


Subject(s)
Antibodies, Bacterial/analysis , Helicobacter Infections/diagnosis , Helicobacter pylori/immunology , Latex Fixation Tests/methods , Anti-Bacterial Agents/therapeutic use , Helicobacter Infections/drug therapy , Helicobacter Infections/microbiology , Humans , Immunoenzyme Techniques , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Remission Induction , Sensitivity and Specificity
9.
J Biol Chem ; 273(49): 32708-14, 1998 Dec 04.
Article in English | MEDLINE | ID: mdl-9830013

ABSTRACT

The mouse mammary tumor virus (MMTV) promoter has target sequences recognized by several steroid receptors. We present evidence for a novel mechanism that confers hormone specificity to this promoter. We show that remodeling of MMTV chromatin and the concomitant activation of the MMTV promoter are induced equally by glucocorticoids and progestins in one chromosomal context but are selective for glucocorticoids in another. Furthermore, increased histone acetylation modulates MMTV promoter regulation disparately at the two chromosomal locations. Together, these data indicate that chromosomal architecture commands a crucial role in gene regulation, imposing locus-specific selectivity between regulators with similar sequence recognition.


Subject(s)
Chromatin/metabolism , Mammary Tumor Virus, Mouse/genetics , Promoter Regions, Genetic , Steroids/metabolism , Transcriptional Activation , Acetylation , Base Sequence , Cell Line , DNA Primers , Histones/metabolism , In Situ Hybridization, Fluorescence , Luciferases/genetics , Virus Integration
10.
Am J Gastroenterol ; 93(10): 1976-9, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9772069

ABSTRACT

The cause of Ménétrier's disease is unknown, although various autoimmune, allergic, and infective causes have been postulated. This case report describes a 37-yr-old man with Ménétrier's disease associated with protein-losing enteropathy and Helicobacter pylori infection. Clinical, endoscopic, histological, and biochemical resolution occurred after treatment of Helicobacter pylori infection. The improvement observed in this case supports an etiological role for H. pylori infection in Ménétrier's disease.


Subject(s)
Gastritis, Hypertrophic/microbiology , Helicobacter Infections , Helicobacter pylori , Adult , Drug Therapy, Combination , Gastric Mucosa/pathology , Gastritis, Hypertrophic/complications , Gastritis, Hypertrophic/pathology , Helicobacter Infections/complications , Helicobacter Infections/drug therapy , Helicobacter Infections/pathology , Humans , Male , Protein-Losing Enteropathies/complications
12.
Aliment Pharmacol Ther ; 12(7): 641-5, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9701527

ABSTRACT

BACKGROUND: Rapid whole blood tests for Helicobacter pylori infection were developed to assist in the management of patients with dyspepsia in general practice. However, they have not been extensively tested in this setting. AIM: To investigate the test characteristics of the BM-Test (Helisal Quick Test) when used in general practice. METHOD: One hundred and ten dyspeptic patients attending local general practitioners were recruited into the study. The BM-Test was administered by the general practitioner at the screening visit according to standard instructions supplied with the test kit. The patient was then referred to Nepean or Mornington Peninsula Hospitals for further assessment. including a 14C-urea breath test. The test kit was forwarded to the appropriate hospital centre for an independent, blinded reading. The sensitivity and specificity of the BM-Test were evaluated against the results of the 14C-UBT. RESULTS: Based on general practitioner readings, the BM-Test had a sensitivity of 59.3% and a specificity of 90.2%. The positive and negative predictive values were 87.5% and 65.7%, respectively. When based on independent readings, sensitivity rose to 71.2% and specificity fell to 88.2%. The BM-Test was more sensitive for older patients than for younger patients when based on both the general practitioner and independent readings. CONCLUSION: The BM-Test performs below the generally recommended sensitivity and specificity of 90% required for clinical practice.


Subject(s)
Antibodies, Bacterial/blood , Helicobacter Infections/diagnosis , Helicobacter pylori/isolation & purification , Reagent Kits, Diagnostic , Adult , Age Distribution , Aged , Aged, 80 and over , Australia/epidemiology , Breath Tests , Evaluation Studies as Topic , Family Practice , Female , Helicobacter Infections/blood , Helicobacter Infections/epidemiology , Helicobacter pylori/immunology , Humans , Male , Middle Aged , Predictive Value of Tests , Prevalence
13.
Am J Gastroenterol ; 93(7): 1080-4, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9672334

ABSTRACT

OBJECTIVE: Current literature was reviewed analyzing the outcome of peptic ulcer healing in relation to the results of the posttherapeutic Helicobacter pylori (HP) status. METHODS: Literature was reviewed along with an analysis of 60 studies, comprising a total of 4329 patients. RESULTS: Successful Helicobacter pylori eradication was found to induce a better response in peptic ulcer healing, regardless of diagnosis: gastric ulcer 88% vs 73% (odds ratio [OR] 2.7, p < 0.01), duodenal ulcer 95% vs 76% (OR 5.6, p < 0.0001), and peptic ulcer 95% vs 76% (OR 6.6, p < 0.0001), for patients having their HP infection successfully cured versus those remaining HP-positive, respectively (Fisher's exact test). For all evaluated time points (< or = 6, 7-8, and 10-12 wk after beginning treatment), HP-negative patients had higher healing rates than HP-positive patients (95% vs 82%, 94% vs 69%, and 96% vs 78% with corresponding OR of 4.2, 6.5, and 7.4, all p < 0.0001, Fisher's exact test). The use of concomitant acid suppression therapy during initial HP eradication provided a benefit on peptic ulcer healing only for patients with persistent HP infection (improved healing rates of 78% vs 67%; otherwise rates were 94-96%). Likewise, prolonged acid inhibition in HP treatment failures after the initial HP treatment phase resulted in 7-20% improved healing rates, whereas patients becoming HP-negative did not profit. CONCLUSION: Successful HP eradication therapy accelerates peptic ulcer healing even without concomitant acid suppression.


Subject(s)
Helicobacter Infections/therapy , Helicobacter pylori , Peptic Ulcer/microbiology , 2-Pyridinylmethylsulfinylbenzimidazoles , Antacids/therapeutic use , Anti-Ulcer Agents/therapeutic use , Benzimidazoles/therapeutic use , Duodenal Ulcer/drug therapy , Duodenal Ulcer/microbiology , Gastric Acid/metabolism , Humans , Lansoprazole , Odds Ratio , Omeprazole/analogs & derivatives , Omeprazole/therapeutic use , Pantoprazole , Peptic Ulcer/drug therapy , Ranitidine/therapeutic use , Stomach Ulcer/drug therapy , Stomach Ulcer/microbiology , Sulfoxides/therapeutic use , Treatment Outcome , Wound Healing
14.
Int J Dermatol ; 37(6): 454-6, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9646137

ABSTRACT

BACKGROUND: An improved understanding of patients' attitudes to medication may help promote compliance with oral medications for onychomycosis. This study was performed to assess patients' preference between continuous and intermittent oral treatment schedules for onychomycosis and to determine the reasons underlying the selections made. METHODS: Patients were eligible for inclusion if they had current onychomycosis and were willing to take oral medication for this condition. In a 30-min, face-to-face interview, each patient answered questions about four possible treatment schedules for onychomycosis; regimen 1--continuous (daily regular intake) for 12 weeks; regimen 2--intermittent 1 week/month for 3 months (last week of therapy is week 9); regimen 3--intermittent once weekly for 21 weeks; regimen 4--intermittent 1 week/month for 4 months (last week of therapy is week 13). RESULTS: A total of 102 patients from Germany and Spain participated in the study. When asked to choose between regimens 1, 2, and 3, 46% of patients favored the 9-week intermittent schedule, 42% selected the 12-week continuous schedule, and 12% preferred the 21-week intermittent schedule. The preference for the 9-week intermittent schedule was more notable among younger patients (< 45 years), possibly because they are less used to taking regular medication, and among Spanish patients, an effect that could not be attributed to age because the average age of patients was similar in the participating countries (Germany 47.2 years; Spain 48.0 years). When the patients who preferred regimen 2 were asked to choose between regimens 1, 3, and 4 (both intermittent schedules longer than the continuous schedule), most (57%) favored the shortest treatment schedule (regimen 2). CONCLUSIONS: Overall, patients favored an intermittent schedule lasting 9 weeks. Treatment duration is the critical factor in determining patients' preference for treatment schedules for onychomycosis.


Subject(s)
Antifungal Agents/administration & dosage , Onychomycosis/drug therapy , Patient Compliance , Administration, Oral , Adult , Drug Administration Schedule , Female , Foot Dermatoses/drug therapy , Germany , Hand Dermatoses/drug therapy , Humans , Male , Middle Aged , Spain , Surveys and Questionnaires
15.
J Gastroenterol Hepatol ; 13(5): 505-10, 1998 May.
Article in English | MEDLINE | ID: mdl-9641649

ABSTRACT

The aims of this study were to assess the prevalence of Helicobacter pylori and its relationship with different epidemiological factors in an Anglo-Celtic Australian population in the Melbourne urban area. Two hundred and seventy-three (120 men and 153 women with a mean age of 55.6 and range of 20 to 80 years) of 396 eligible subjects randomly sampled from the telephone directory were studied. An ELISA technique was used to detect H. pylori immunoglobulin (Ig)G antibody and self-administered questionnaires were completed. The overall seroprevalence of H. pylori was 38% and increased with age from 18% (20-30 years old) to 53% (over 70 years; P < 0.0001). The acquisition of H. pylori infection was 1% per year. The prevalence of H. pylori was 48% in men and 30% in women (P < 0.01). The frequency of H. pylori was also associated with low-income levels and current smoking, but was not associated with peptic ulcer disease history. The prevalence of H. pylori infection in a representative Australian population was found to be similar to other developed countries. The risk factors for H. pylori infection include age, male sex, low household income and a smoking habit. No correlation between H. pylori status and dyspepsia symptoms were observed.


Subject(s)
Ethnicity , Helicobacter Infections/epidemiology , Helicobacter pylori , Adult , Age Factors , Aged , Aged, 80 and over , Australia/epidemiology , Female , Humans , Male , Middle Aged , Regression Analysis , Sex Factors , Social Class
16.
Aust Dent J ; 43(1): 35-9, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9583224

ABSTRACT

Recent studies suggest Helicobacter pylori is spread by faecal-oral or oral-oral transmission. Gastroenterologists who are exposed to gastric secretions and saliva have a high prevalence of H. pylori infection. Venous blood was obtained from 92 dentists, 40 dental nurses, 33 fifth year and 30 first year dental students. An ELISA assay was used to detect H. pylori IgG antibodies. Results were compared with an age and sex matched normal population. The prevalence of H. pylori infection in dentists, dental nurses, fifth year dental students and first year dental students were 23 per cent, 18 per cent, 18 per cent and 16 per cent, respectively. There were no significant differences when compared with the normal population controls. The prevalence of H. pylori antibody was not significantly increased with years of practice or patient contact time in dentists and dental nurses. Helicobacter pylori infection is uncommon in dental professionals working in the oral cavity.


Subject(s)
Dental Assistants , Dentists , Helicobacter Infections/epidemiology , Helicobacter pylori , Occupational Diseases/epidemiology , Students, Dental , Adolescent , Adult , Age Factors , Aged , Antibodies, Bacterial/blood , Case-Control Studies , Chi-Square Distribution , Enzyme-Linked Immunosorbent Assay , Female , Gastroenterology , Helicobacter Infections/immunology , Helicobacter Infections/transmission , Helicobacter pylori/immunology , Humans , Immunoglobulin G/blood , Infection Control , Infectious Disease Transmission, Patient-to-Professional , Logistic Models , Male , Middle Aged , Occupational Diseases/immunology , Prevalence , Sex Factors , Time Factors , Victoria/epidemiology
17.
Asia Pac J Clin Nutr ; 7(1): 88-93, 1998 Mar.
Article in English | MEDLINE | ID: mdl-24394903

ABSTRACT

We found that with oral supplementation by a liquid soy-based protein hydrolysate in malnourished COPD patients (BMI <= 20), it possible to increase weight over a 6-week period, and body water and an index of muscle mass (MAMC), but not total body nitrogen (TBN judged by Nitrogen Index) which identifies a particular challenge for nutrition support in COPD patients. There was no associated improvement in pulmonary function but we found that better nourished COPD patients (BMI > 20) had some pulmonary function advantage; it is suggested that TBN may need to improve with nutrition support for pulmonary function to improve.

18.
Dig Dis Sci ; 42(11): 2327-32, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9398813

ABSTRACT

Classical eosinophilic gastroenteritis is a rare disease but may be misdiagnosed in clinical practice. We report eosinophilic gastroenteritis that was diagnosed in six patients (four males and two females; mean age 31.5 years) using standard criteria (presence of gastrointestinal symptoms, a predominant eosinophilic infiltrate on biopsy, and exclusion of other causes of eosinophilia). All had gastric mucosal disease and presented with dyspepsia. The median duration of symptoms prior to diagnosis was three months (range five weeks to 13 years). Epigastric pain or discomfort was the most common symptom (100%) followed by anorexia, nausea, and vomiting (67%, 67% and 33%, respectively). None had diarrhea. Half the patients had a history of allergy, while 67% had peripheral eosinophilia. All responded to oral steroids within two months; one third needed to continue on a small dose of maintenance steroids to remain in remission. A high degree of suspicion and biopsy at upper endoscopy is necessary for diagnosis of this rare disease.


Subject(s)
Dyspepsia/etiology , Eosinophilia/complications , Gastroenteritis/complications , Adolescent , Adult , Aged , Anti-Inflammatory Agents/therapeutic use , Duodenum/pathology , Eosinophilia/drug therapy , Eosinophilia/pathology , Gastroenteritis/drug therapy , Gastroenteritis/pathology , Humans , Male , Prednisolone/therapeutic use
19.
Aliment Pharmacol Ther ; 11 Suppl 1: 27-33, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9146788

ABSTRACT

Bismuth salts have been used in medicine for over three centuries, particularly in the treatment of dyspepsia. Commonly used agents include colloidal bismuth subcitrate (CBS), bismuth subsalicylate (BSS) and the newer ranitidine bismuth citrate (RBC). These are safe drugs which exert local effects on the gastroduodenal mucosa. Gastric mucosal levels of bismuth exceed the concentrations required to kill Helicobacter pylori in vitro. The mechanisms of actions of bismuth on gastrointestinal pathogens including H. pylori are complex and include inhibition of protein and cell wall synthesis, membrane function and ATP synthesis. Adherence of H. pylori to surface epithelial cells is also impaired. Bismuth monotherapy is effective in vivo to suppress H. pylori but cure rates are low. CBS, BSS and RBC have synergistic activity with one or two antibiotics and are effective in eradicating H. pylori. CBS and RBC also exert other effects on the mucosa including cytoprotective and ulcer healing properties. In addition, RBC is effective in inhibiting gastric acid secretion.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bismuth/therapeutic use , Helicobacter Infections/drug therapy , Helicobacter pylori , Histamine H2 Antagonists/therapeutic use , Organometallic Compounds/therapeutic use , Ranitidine/analogs & derivatives , Salicylates/therapeutic use , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Bismuth/administration & dosage , Bismuth/pharmacology , Drug Synergism , Duodenum/drug effects , Duodenum/metabolism , Gastric Acid/metabolism , Gastric Mucosa/drug effects , Gastric Mucosa/metabolism , Helicobacter pylori/drug effects , Helicobacter pylori/metabolism , Histamine H2 Antagonists/administration & dosage , Histamine H2 Antagonists/pharmacology , Humans , Organometallic Compounds/administration & dosage , Organometallic Compounds/pharmacology , Ranitidine/administration & dosage , Ranitidine/pharmacology , Ranitidine/therapeutic use , Salicylates/administration & dosage , Salicylates/pharmacology , Treatment Outcome
20.
J Antimicrob Chemother ; 39(3): 331-7, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9096182

ABSTRACT

The bactericidal activity of the proton pump inhibitors omeprazole and lansoprazole alone and in combination with a beta-lactam or macrolide antibiotic were investigated in vitro. Time-kill curves against Helicobacter pylori NCTC 11637 and a recent clinical isolate revealed significant concentration-dependent killing with all drugs other than amoxycillin. Combinations of proton pump inhibitor and erythromycin showed synergic activity. In contrast, proton pump inhibitor plus amoxycillin showed additive activity against the clinical isolate only. Bactericidal investigations of anti-helicobacter drugs in vitro may suggest optimum treatment strategies for this common infectious disease.


Subject(s)
Anti-Bacterial Agents/pharmacology , Helicobacter pylori/drug effects , Proton Pump Inhibitors , 2-Pyridinylmethylsulfinylbenzimidazoles , Amoxicillin/pharmacology , Drug Synergism , Enzyme Inhibitors/pharmacology , Erythromycin/pharmacology , Lansoprazole , Microbial Sensitivity Tests , Omeprazole/analogs & derivatives , Omeprazole/pharmacology
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