Lansoprazole. An update of its pharmacological properties and clinical efficacy in the management of acid-related disorders

Lansoprazole is a proton pump inhibitor that reduces gastric acid secretion. It has proved effective in combination regimens for the eradication of Helicobacter pylori and as monotherapy to heal and relieve symptoms of gastric or duodenal ulcers and gastro-oesophageal reflux. After initial healing, it may be used to prevent recurrence of oesophageal erosions or peptic ulcers in patients in whom H. pylori is not the major cause of ulceration and to reduce basal acid output in patients with Zollinger-Ellison syndrome. Usual dosages are 15 to 60 mg/day, although dosages of < or = 180 mg/day have been used in patients with hypersecretory states. In patients with duodenal or gastric ulcer, short term lansoprazole monotherapy was similar to omeprazole and superior to histamine H2 receptor antagonists in achieving healing rates > 90%. Lansoprazole was as effective a component of H. pylori eradication regimens as omeprazole, tripotassium dicitrato bismuthate (colloidal bismuth subcitrate) or ranitidine. Lansoprazole was superior to ranitidine in symptom relief and healing of gastro-oesophageal reflux disease and tended to relieve symptoms more rapidly than omeprazole, although initial healing was similar. As maintenance treatment, lansoprazole was similar to omeprazole and superior to ranitidine in relieving symptoms and preventing relapse. Lansoprazole was also superior to ranitidine in healing and relieving symptoms of oesophageal erosions associated with Barrett's oesophagus; healing was maintained for a mean of 2.9 years in > or = 70% of patients. Lansoprazole was also superior to ranitidine in prophylaxis of redilatation of oesophageal strictures. After > or = 4 years of use in patients with Zollinger-Ellison syndrome, lansoprazole 60 to 180 mg/day effectively controlled basal acid output. Dosages may be reduced in some patients once healing and symptom relief has been achieved. Preliminary studies of lansoprazole in patients at risk of aspiration pneumonia or stress ulcers show promise. Although studies show lansoprazole is potentially effective in treating gastrointestinal bleeding, future studies should assess patients' H. pylori status. Lansoprazole has been well tolerated in clinical trials, with headache, diarrhoea, dizziness and nausea appearing to be the most common adverse effects. Tolerability of lansoprazole does not deteriorate with age and the drug is well tolerated in long term use (< or = 4 years) in patients with Zollinger-Ellison syndrome or reflux disease. Thus, lansoprazole is an important alternative to omeprazole and H2 receptor antagonists in acid-related disorders. In addition to its efficacy in healing or maintenance treatment, it may provide more effective symptom relief than other comparator agents.     

Defects at center P underlie diabetes-associated mitochondrial dysfunction

Detailed respiration studies on isolated liver mitochondria from streptozotocin-induced diabetic Sprague-Dawley rats revealed a disease-associated decrease in the ADP/O ratio, a marker for mitochondrial ability to couple the consumption of oxygen to the phosphorylation of ADP. This decrease was observed following induction of respiration with glutamate/malate, succinate, or duroquinol, which enter the electron transport chain selectively at complexes I (NADH dehydrogenase), II (succinate dehydrogenase), or III (cytochrome bc1 complex), respectively. These data, coupled with studies using respiratory inhibitors (most importantly antimycin A and myxothiazol), localize at least a portion of this defect to a single site within the electron transport chain (center P in the Q-cycle portion of complex III). These results suggest that liver mitochondria from diabetic animals may generate increased levels of reactive oxygen species at the portion of the electron transport chain already established as the major site of mitochondrial free radical generation. The reduction in the ADP/O ratio occurred in mitochondria that do not have overt defects in the respiratory control ratio or in State 3 and State 4 respiration. The data in this paper suggest that defects in center P of the electron transport chain likely increase mitochondrial exposure to oxidants in the diabetic. This data may partially explain the evidence of altered exposure and/or response to reactive species in mitochondria from diabetics. This work thus provides further clues to the interaction between oxidative stress and diabetes-associated mitochondrial dysfunction.     

The Geometry of Visual Space: About the Incompatibility between Science and Mathematics

We address the problem of a geometrical model of vision. This problem is interesting for at least two reasons. First, any theory of vision (human or computer) must decide which geometry should be used to represent perceived objects (e.g., Euclidean vs projective). We believe that this representation should be compatible with geometrical properties of the imaging device (eye or camera). Second, the analysis of geometrical properties of vision will examine the usefulness of standard geometries and can lead to progress in mathematics itself. We analyze the geometry of image formation and show that human vision appears to involve a new branch of geometry whose properties are quite different from the properties of traditional geometries. We formulate these properties and use them to derive models of shape perception. Finally, we provide perceptual interpretations for our theoretical analyses.     

Generation and characterization of an IGFBP-7 antibody: identification of 31kD IGFBP-7 in human biological fluids and Hs578T human breast cancer conditioned media

The cDNA encoding mac25 (IGFBP-7) was firsr derived from mRNA isolated from leptomeningial and senescent human mammary epithelial cells (1,2). The open reading frame was shown to predict a protein with homology to the amino terminus of the IGF binding proteins, (IGFBP)1-6. Studies in our laboratory have shown that baculovirus generated mac25 binds IGF-I and-II in a specific manner, leading to the renaming of mac25 as IGFBP-7 (3). Further studies at the cellular level, to identify the involvement of IGFBP-7 in IGF regulation and cell growth, require a specific antibody against the protein, which has yet to be identified in either cultured cells or in vivo. We have now generated three polyclonal antibodies against the purified baculovirus peptide and, by western immunoblots and immunoprecipitation, demonstrated the existence of a specific 31,000 dalton protein. It is a secreted protein, and can be identified in the conditioned media of Hs578T breast cancer cells, as well as in normal human urine, cerebrospinal fluid and amniotic fluid. Subsequent studies with these antibodies should help elucidate the physiological role(s) of this protein.     

Dietary modulation of avian coccidiosis

During the past several years, our laboratory has been investigating the anticoccidial activities of various natural products that have potential use as dietary supplements for coccidiosis control. Sources of fats containing high concentrations of n-3 fatty acids such as menhaden oil and flaxseed oil and flaxseed, when added to starter rations and fed to chicks from one day of age, effectively reduce lesions caused by the caecal parasite Eimeria tenella, but not lesions caused by Eimeria maxima. Our results are consistent with reports of effects of diets high in n-3 fatty acids on other protozoan parasites which suggest that the state of oxidative stress induced by these diets in the cells of both host and parasites is responsible for their parasitic actions. Artemisinin, a naturally occurring (Artemisia annua) endoperoxide and effective antimalarial significantly lowers lesions from E. tenella when given at low levels as a feed additive. The mechanism of its action is also considered to involve induction of oxidative stress. Diets supplemented with 8 p.p.m. gamma-tocopherol (abundant in flaxseeds) or with 1% of the spice tumeric, reduce mid-small intestinal lesion scores and improve weight gains during E. maxima infections. These compounds may exert their anticoccidial activity because they are effective antioxidants. Betaine, a choline analogue found in high concentrations in sugar beets, improves nutrient utilisation by animals under stress. When provided as a dietary supplement at a level of 0.15% it has enhanced the anticoccidial activity of the ionophore, salinomycin. Betaine may act as an osmoprotectant whereby it improves the integrity and function of the infected intestinal mucosa. In in vivo studies, betaine plus salinomycin significantly inhibit invasion of both E. tenella and E. acervulina. However, subsequent development of E. acervulina is inhibited more effectively with this combination treatment than development of E. tenella.     

Psoriasiform onychopachydermoperiostitis of the large toes: the OP3GO syndrome

OBJECTIVE: To describe our experience with primary appendiceal tumours. DESIGN: Retrospective study. SETTING: University hospital, Israel. SUBJECTS: 2520 patients who had appendectomies during the 14 years, January 1982-December 1996. RESULTS: 22 patients 5 male and 17 female, mean age 56.2 years, had primary neoplasms; 14 were carcinoid tumours and villous adenomas and were treated by appendicectomy only. Adenocarcinoma was diagnosed in 8 patients (0.3%), 5 after appendicectomy (0.2%) which is twice the reported incidence. They were all treated by right hemicolectomy. Seven of the patients were classified as Dukes' B and one as Dukes' C. All patients were alive and disease-free after a mean follow-up period of 57.4 months. CONCLUSION: Right hemicolectomy is the treatment of choice for adenocarcinoma of the appendix.     

Neuroendocrine differentiation is an independent prognostic factor in chemotherapy-treated nonsmall cell lung carcinoma

BACKGROUND: Neuroendocrine differentiation can be identified in 10-30% of patients with nonsmall cell lung carcinoma (NSCLC) by immunohistochemical or electron microscopic techniques. However, its clinical significance is not well established. METHODS: Tumors from 107 patients with Stage IIIA, IIIB, and IV NSCLC treated with cisplatin/etoposide with or without hydrazine in the North Central Cancer Treatment Group and Mayo Clinic protocols were analyzed immunohistochemically with antibodies to chromogranin A (CGA), Leu 7 (CD 57), and synaptophysin (SY). These results were compared with clinical outcomes. RESULTS: Keratin AE1/AE3, used as a control, was positive in 99.1% of cases; 34.6% had positive staining for at least 1 neuroendocrine marker, and 11.3% had positive staining for 2 or more markers. CGA was positive in 4.7%, Leu 7 in 18.7%, and SY in 24.3% of cases. A significant increase in survival was seen in patients with tumors expressing any one neuroendocrine marker or any combination of neuroendocrine markers (P < or = 0.01). There was no correlation between the presence of neuroendocrine differentiation and either response to chemotherapy or time to disease progression (P > 0.3), nor was there any correlation between chemotherapy response, time to progression, or survival with staining intensity or percent of cells positive per case. CONCLUSIONS: Neuroendocrine differentiation may be of prognostic significance in patients with advanced stage NSCLC treated with chemotherapy.