Helicobacter pylori is a gram-negative bacterium that forms the etiology of chronic gastritis and peptic ulcer disease. Infection with H. pylori can be effectively treated by the combination of a proton pump inhibitor in addition Clarithromycin and amoxicillin. Emergence of Clarithromycin resistant strains of was not well studied in Sudan. Clarithromycin is a macrolide that binds to the 23S rRNA components of the bacterial ribosome. Resistant strains emerge due to failure of such binding because of modification of the target site by point mutations in the peptidyl transferase region of domain V of the 23S rRNA. H. pylori contain two copies of the 23S rRNA gene8. Several points mutations have been reported that are associated with macrolide resistance, but the most common is A-G transitions at position 2143 (A2143G).
The discovery of Helicobacter pylori as the cause of peptic ulcer has revolutionized anti-ulcer treatment. The current treatment includes a combination of antibiotics with proton pump inhibitors or H2 receptor antagonist1,2. Clarithromycin and omeprazole combination has become popular and best choice for treating peptic ulcer associated with H. pylori infection3. Gastro retentive dosage forms have the potential for increased residence in stomach along with site-specific drug delivery. Hydrodynamic drug delivery systems (HBS) are one such systems that has increased gastric residence providing an increased local action at the ulcer site4. Clarithromycin, effective in H.pylori infection treatment was chosen as model drug. Extended release and retention in upper gastro intestinal tract would be most advantageous, optimizing the combination therapy of peptic ulcer complicated with H.pylori. Omeprazole was formulated as fast dissolving enteric-coated pellets by using extrusion spheronisation technique. Enteric coating material used was Eudragit 30D-L-55.
High Quality Content by WIKIPEDIA articles! A peptic ulcer, also known as ulcus pepticum, PUD or peptic ulcer disease, is an ulcer (defined as mucosal erosions equal to or greater than 0.5 cm) of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. As many as 80% of ulcers are associated with Helicobacter pylori, a spiral-shaped bacterium that lives in the acidic environment of the stomach, however only 40% of those cases go to a doctor. Ulcers can also be caused or worsened by drugs such as aspirin and other NSAIDs.
Hyper-chlorohydria has been long implicated in the etiology of duodenal ulcer(DU). Of late, H. pylori has been associated in the pathogenesis. while hyper-chlorohydria and Helicobacter infection can act throughout the gastroduodenum, it remains unexplained, why there should have predilection for certain well documented and specific sites for peptic ulceration. It has to be explained whether they produce any change in other parts of the stomach besides the ulcer site.Recent works like eradication of H. pylori, leading to healing of peptic ulcer diseases(PUDs) have given encouraging results and proved beyond doubt an association between H. pylori and PUD. Pain,a well known symptom of DU is often experienced throughout the stomach, often associated with generalized tenderness of the epigastrium suggesting possible generalized involvement of the gastric wall. In some cases of CDU, gross dilatation of stomach wall with generalized hypotonia is a common finding. In some others, hypertonic stomach with same pathology is not uncommon. It would therefore be interesting to study the structural changes in the stomach wall in CDU patients which i have tried to describe in this book.
An optimized Ethylcellulose microspheres of Clarithromycin were successfully prepared using emulsion/ solvent evaporation method and Con-A was successfully attached to the microspheres using carbodiimide method. Attachment of lectin to the Ethylcellulose microspheres significantly increased the mucoadhesiveness and also controls the release of Clarithromycin in simulated GI fluids. Conjugation aggregation assay suggesting that the lectin can be able to target in the treatment of Helicobacter pylori infection in peptic ulcer disease. Gamma scintigraphy study suggesting that Con-A lectin conjugated Ethylcellulose microspheres have gained considerable attention due to their ability to adhere to the mucus layer, as well as to release the drug in a controlled manner. It is concluded that designed targeted delivery system could possibly increases the bioavailability of Clarithromycin and treated the gastric ulcer in an effective manner.
More than 50% of the world's population harbor Helicobacter pylori in their upper gastrointestinal tract. H. pylori persistently infects gastric mucosa and is associated with several diseases including peptic ulcer disease and gastric carcinoma. One of the most thoroughly studied virulence factors produced by H. pylori is the Vacuolating Cytotoxin A (VacA).The protein binds to the host cells and is internalized. Inside the host cells, it causes "vacuole"-like membrane vesicles in the cytoplasm of gastric epithelial cells. Besides vacuolation, VacA exerts various other effects on target cells. VacA also forms membrane-embedded pores at the inner-mitochondrial membrane, resulting in mitochondrial dysfunction by cytochrome c release and apoptosis induction. VacA suppresses nuclear translocation of nuclear factor of activated T-cells (NFAT) resulting in down regulation of interleukin-2 (IL2) gene transcription to efficiently block proliferation of T-cells. This book underlines the results showing involvement of VacA in the modulation of intracellular calcium signalling and therefore will provide new insights that are required to understand how VacA inhibits T-cell proliferation.
Helicobacter pylori (H. Pylori) infection is associated with many upper gastrointestinal diseases such as chronic gastritis, peptic ulcer and gastric carcinoma. Furazolidone is an effective drug in the treatment of GIT infections. Furazolidone has short half-life and need to administrate on frequent basis. This book discuss design, development and optimization of sustained release intra-gastric in situ floating gel system of Furazolidone for the potential use in treatment of gastric and duodenal ulcers associated with H. Pylori. Furazolidone gelling solution (FISG) was prepared using natural biodegradable polymers Xanthan gum, Gellan gum and Locust bean gum. The polymeric system was optimized by calcium carbonate and sodium citrate. Effect of beta CD was also evaluated. The optimized FISG was evaluated for gelling properties, floating lag time, rheological properties, drug content, FT-IR and DSC. All optimized solutions had shown pseudoplastic flow with good gel strength and gelled immediately at acidic pH 1.2. The dissolution study indicated sustained release of drug. The book will be useful for the researchers working in the areas of formulation development of pharmaceuticals.
Helicobacter pylori is one of the most common causes of chronic infections in human. A close relationship is now thought to exist between H. pylori and peptic ulcer disease, gastritis, and certain other gastroduodenal diseases. Also, it is now firmly established that infection with H. pylori is a key etiological factor in peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Furthermore, several studies have shown that eradication of H. pylori plays an important role in the treatment of some gastric-intestinal diseases. Biopsy specimens were collected from 150 dyspeptic patients. One hundred and seven were positive for H. pylori. Susceptibilities were determined for these isolates by disc diffusion methods. The prevalence of positive H. pylori isolates among the dyspeptic patients was 71.33%. The resistance rate to metronidazole, tetracycline, clarithromycin, and amoxicillin was 86%, 7.4%, 5.6%, and 0.9%, respectively. Metronidazole resistance was a character of H. pylori isolates within most patients in Ismailia, while amoxicillin resistance is rare.
Gastric (mainly peptic) ulcer is one of the major factors affecting about 60% of the human population in the tropical countries.It is interesting to note that nearly 50% of the Indian population harbors the disease.Peptic ulcer as a disease is characterized by a group of disorders described lesions of the upper gastrointestinal tract (with stomach and duodenum being the most affected areas The local factors that are responsible for causing peptic ulcers can be categorized as: Aggressive factors Hydrochloric acid, Pepsin, refluxed bile, on-steroidal Anti-inflammatory Drugs, Alcohol, Proteolytic enzymes, ingested irritants, bacterial toxins,etc Defensive factors Mucus, bicarbonates, blood flow,prostaglandins,etc. Microbial factors Helicobacter pylori infection. It is generally acknowledged that an ulcer results from an imbalance between th Aggressive gastric factors and the defensive (resistance) factors.The treatment should aim at correcting this imbalance rather than neutralizing/inhibiting gastric acid only.The present work makes such an attempt using herbal drugs.