bluuebunny/crossref_metadata_2025 huggingface dataset:
Interception, pH and solid content of rainfall in a Nigerian lowland rain forest
Authors: Muoghalu Joseph Ikechukwu , Johnson Solomon Oluwafemi
Published: March 2003

Rainfall interception by forest trees, pH, alkalinity, total suspended and dissolved solids of incident rainfall, stemflow and throughfall and the effect of tree species in these parameters were investigated in three open sites and a secondary rain forest at Ile‐Ife, Nigeria, in 1994 and 1995. The tree species Blighia sapida, Holarrhena floribunda and Piptadeniastrum africanum intercepted different proportions of incident rainfall, 1.6, 39.4, and 7.4%, respectively. The pH of stemflow was higher than that of throughfall and the pH of both was always higher than that of incident rainfall. The total suspended solids were higher at the beginning and towards the end of the rainy season. The total dissolved solids concentration in all rainfall fractions was highest at the early rains and during the heavy rain months, especially in throughfall and stemflow. The total suspended and dissolved solids concentration of stemflow was higher than that of throughfall and those of both were higher than that of the incident rain. Total alkalinity of incident rainfall and throughfall decreased, while that of stemflow increased with increase in rainfall. There were significant differences in the alkalinity of stemflow and throughfall under the crowns of the tree species.
Landscape monitoring of semi‐arid rangelands in the Kenyan Rift Valley
Authors: Agnew A. D. Q. , Mwendia C. M. , Oloo G. O. , Roderick S. , Stevenson P.
Published: March 2003

A sampling system was devised and used from 1992 to 1996 in annual grassland and open woodland of the south‐west Kenyan Rift Valley. The monitoring was designed to detect vegetation changes consequent on the attempted removal of the tsetse vectors of trypanosomiasis in cattle during a simultaneous trapping programme. The sampled sites covered most vegetation‐landscape types, and have led to a better understanding of processes within some. Although fluctuations in pastoralist use and occupancy have been observed, no change in vegetation can be attributed to increased grazing or browsing. Although there is high climatic variability some vegetation types seemed stable over the period studied, and some trends appear to be predictable.
Notes and records
Authors: Muchoki Charles H. K.
Published: March 2003

Sustainable use and management of resources require regular monitoring. In the case of animals, their numbers and distributions are important in determining future trends. The data can also be used for planning and management needs such as habitat use and design of park boundaries ( Norton‐Griffiths, 1978).

Aerial surveys in East Africa have collected data on animal numbers and other environmental parameters coinciding with wet, intermediate and dry seasons and hence determining animal movements in relation to their food supply ( Western, 1975;
Norton‐Griffiths, 1978;
Sinclair & Norton‐Griffiths, 1979). Population trends of animals and their food supply has a bearing on their sustained management in an ecosystem as noted by
Kalikawe & Kgathi (1993),
Lamprey (1984),
Kahurananga (1981),
Western (1973) among others. The Department of Resource Surveys and Remote Sensing has been conducting aerial surveys in Ewaso Nyiro basin since 1977 and the cardinal objective of this paper is to present and explain an analysis of animal population trends in this basin spanning a period of 20 years, which is invaluable to the sustainable management of the basin’s biodiversity.
Population trends of large non‐migratory wild herbivores and livestock in the Masai Mara ecosystem, Kenya, between 1977 and 1997
Authors: Ottichilo Wilber K. , De Leeuw Jan , Skidmore Andrew K. , Prins Herbert H. T. , Said Mohammed Y.
Published: March 2003

The total of all non‐migratory wildlife species in the Masai Mara ecosystem has declined by 58% in the last 20 years. This decline ranges from 49% in small brown antelopes to 72% in medium brown antelopes. In individual wildlife species, the decline ranges from 52% in Grant's gazelle to 88% in the warthog. Declines of over 70% have been recorded in buffalo, giraffe, eland and waterbuck. Only elephant, impala and ostrich have not shown any significant decline or increase. Overall, there has not been any significant difference in decline of all wildlife population sizes inside and outside the reserve, except for Thomson's gazelle and warthog. Livestock have not significantly declined over the entire analysis period. However, livestock and cattle populations significantly declined during the 1983–88 period. Donkey declined by 67%, while shoats (goats and sheep) remained stable. In the case of wildlife, land use and vegetation changes, drought effects and poaching are considered to be among the potential factors that may have been responsible for the decline; the decline in livestock during the 1983–84 period was probably due to drought effects.
Effect of gap size and age on climber abundance and diversity in Budongo Forest Reserve, Uganda
Authors: Babweteera Fred , Plumptre Andrew , Obua Joseph
Published: March 2003

A study of the effects of gap size and age on climber abundance and diversity was carried out in Budongo Forest Reserve in Uganda. Data were collected from compartments N5, W21, B1 and B3. Stump records were used to locate and estimate the ages of 78 gaps. Sample plots 5 × 5 m were set up in the gaps to assess climber abundance and diversity.

Climbers were more abundant and diverse in gaps that were more than 400 m2, 15 months old and had more than 25% canopy opening. Momordica foetida was the most abundant climber species occurring on stems, branches and crowns of seedlings and saplings. Therefore, in order to keep natural regeneration free from climber tangles and produce good quality timber, climber control should be a major activity in tropical high forest management.
Seasonal abundance, reproduction and hunting of common quail Coturnix coturnix in the Eastern Cape Province, South Africa
Authors: Kerley Graham I. H. , Watson Justin J. , Boshoff André F.
Published: March 2003

This study investigated the potential overlap between breeding and hunting seasons for a population of common quail Coturnix coturnix in the Alexandria District. Seasonal abundance (assessed as the number of birds flushed per unit effort), sex ratios and reproductive condition (based on gonad sizes) of the quail were measured over a period of 16 months, including two hunting seasons. Hunting impacts were assessed in terms of the number of birds killed per unit of hunting effort. Quail exhibited a spring peak in abundance and reproduction, which coincided with the legal hunting season, and bird numbers varied markedly between years. Sex ratio varied, with males dominating early in spring. Hunters killed nearly 60% of the birds flushed, and hunter efficiency was positively correlated with the abundance of quail. These results confirm the dilemma for managers, as quail are currently hunted during the main breeding season and offtakes are high. The development of management strategies is hampered by a lack of understanding of the population biology and ecology, and impacts of hunting. A number of possible hunting strategies are discussed. Since current harvests may not be sustainable, further research is necessary.
Ecology of a diplozoon parasite on the gills of the African cyprinid Barbus neumayeri
Authors: Chapman Lauren J. , Lanciani Carmine A. , Chapman Colin A.
Published: March 2003

In oxygen‐deficient waters, the difficulties of oxygen uptake in gill parasites and their fish hosts may influence host and parasite densities, site selection by the parasite, and effects of the parasite on host condition. This study quantified the prevalence and intensity of the gill monogenean Neodiplozoon polycotyleus in the African cyprinid fish Barbus neumayeri from an intermittent forest stream in western Uganda. Oxygen levels were low in the stream over the 12‐month study, averaging only 2.5 mg litre−1 (monthly range = 1.2–4.3 mg litre−1). However, parasite prevalence was high (47.2%), suggesting high tolerance to low oxygen in N. polycotyleus. The prevalence of parasites varied with host body size, with the highest frequency of occurrence in the middle size classes. Prevalence also varied over the year; seasonal peaks of rainfall coincided with a lower frequency of N. polycotyleus. The significantly nonrandom frequency distribution of parasites among hosts suggests regulation of parasite numbers. Of the hosts infected, 37.1% harboured one N. polycotyleus parasite, and 62.9% harboured two parasites. No fish were infected with more than two diplozoons. There was evidence for strong site specificity by N. polycotyleus within hosts; 77.7% of the parasites were located on the filaments of the second gill arch, which may relate to increased oxygen availability. In addition, only one of the 178 infected fish had more than one parasite on one side of the branchial basket. Although N. polycotyleus is undoubtedly parasitic, we found no evidence of a negative parasitic effect on the condition or reproductive status of B. neumayeri.
Habitat utilization and home range of the redwing francolin, Francolinus levaillantii, in highland grasslands, Mpumalanga province, South Africa
Authors: Jansen R. , Little R. M. , Crowe T. M.
Published: March 2003

The effects of intensive commercial livestock farming on the distribution and habitat use of the redwing francolin, Francolinus levaillantii, was investigated to identify habitat constraints that may contribute towards the observed decline of this species on livestock farms. Data on the size, placement of the home ranges and compositional habitat use from ten radio‐tracked individuals, five in commercially grazed (and frequently burned) and five in protected (and infrequently burned) highland grasslands, was collated to determine habitat preferences. Mean home range size within protected and grazed grassland study sites were similar and ranged between 7.6 and 15.4 hectares. However, habitat use by groups in grazed grasslands was restricted to areas of greater cover and food availability. Group sizes were significantly larger in protected (mean 3.77, n = 111 coveys) than in grazed and frequently burned grassland (mean = 2.96, n = 135 coveys). Smaller coveys in grazed habitats had smaller home ranges and were further spaced from one another. It is therefore suggested that habitat degradation, through excessive defoliation of the grassland from heavy grazing and frequent burning, both fragments francolin subpopulations and reduces the ecological availability of suitable habitat. Thus, undermining the metapopulation structure of the redwing francolin in these commercially grazed grasslands.
Demography of a West African kob (Kobus kob kob) population
Authors: Fischer Frauke , Linsenmair K. Eduard
Published: March 2003

The kob (Kobus kob kob) population studied in the Comoé National Park, Ivory Coast, suffered unsustainable losses to poaching before and during the investigation. This in turn did not only lead to low densities but also changed the population composition, resulting in a strong female bias in all age classes except juveniles. The relative rarity of adult males probably had negative effects on the population recruitment. Although mating occurred throughout the year and birth intervals were short, at least in some females, annual birth‐rate was low compared to earlier studies in the same area. Effective conservation measures are urgently needed to ensure the future existence of the studied population.
An investigation into the composition, complexity and functioning of snake communities in the mangroves of south‐eastern Nigeria
Authors: Luiselli Luca , Akani Godfrey C.
Published: March 2003

The structure of the snake community was studied between 1996 and 2000 on a transect in the mangrove ecological zone of southern Nigeria, West Africa. In three major habitats, both taxonomical diversity and frequency of observations in relation to sampling effort were investigated. In general terms, the complexity of the snake community appeared less than in other habitats of the same geographic region (i.e. swamp forest and forest–plantation mosaics). In fact, only eighteen species were recorded, whereas 43 species are known to inhabit neighbouring habitats. A Principal Component Analysis allowed arrangement of the various species into two main groups in relation to the habitats of capture: (1) a group of species of rainforest biota (i.e. Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae), and (2) a group of species that, at least in Niger Delta, are typically linked to altered habitats, including derived savannas, plantations and suburbia (i.e. Psammophis cf. phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). The community structure in terms of food habits and body sizes appeared similar to those of other snake assemblages from different habitats of southern Nigeria. The conservation implications of our results are also discussed.
High molecular protein of Helicobacter pylori responsible for inhibition of ornithine decarboxylase activity of human gastric cultured cells
Authors: Takashima T. , Fujiwara Y. , Watanabe T. , Tominaga K. , Oshitani N. , Higuchi K. , Matsumoto T. , Arakawa T. , Hasuma T. , Yano Y. , Otani S.
Published: March 2003

Background:

Ornithine decarboxylase (ODC), a rate‐limiting enzyme of polyamine biosynthesis, mediates epithelial cell proliferation and plays a critical role in the optimal repair of gastric mucosal damage. Several studies have shown that Helicobacter pylori inhibits the growth and proliferation of gastric cells in vitro.

Aim:

To test whether H. pylori extract affects ODC mRNA expression and its enzyme activity in gastric cells and to examine the partial characterization of the molecule responsible for this effect.

Methods:

Human gastric cells (MKN‐45) were used. Bacterial extracts from various E. coli or H. pylori strains, namely (1) cagA+, vacA+, CagA+, VacA+; (2) cagA+, vacA+, CagA+ VacA–; or (3) cagA–, vacA+, CagA–, VacA– were added to the cells. Cell proliferation was assessed by [3H]‐thymidine incorporation, viability by MTT assay and LDH release test, ODC enzyme activity by 14CO2 counts from L‐[114C]ornithine, and ODC mRNA by Northern blotting.

Results:

H. pylori and E. coli extract did not affect viability of gastric cells. H. pylori extract, especially extracts containing a protein greater than 50 kDa, significantly inhibited proliferation and ODC activity of gastric cells while E. coli extract had no effect. Inhibition of ODC activity was found in extracts of all H. pylori strains, irrespective of CagA and VacA protein expression. Serum stimulation induces an increase in ODC mRNA while H. pylori extract did not affect ODC mRNA expression.

Conclusion:

High molecular weight (greater than 50 kDa) proteins of H. pylori extract without CagA or VacA protein inhibited proliferation and ODC activity of human gastric cells, but did not affect ODC mRNA expression, suggesting that inhibition of ODC activity is regulated at the post‐transcriptional level.
Gastric ulcerogenic responses following barrier disruption in knockout mice lacking prostaglandin EP1 receptors
Authors: Takeuchi K. , Ogawa Y. , Kagawa S. , Ukawa H.
Published: March 2003

Background/aims:

Endogenous prostaglandins (PGs) are considered to play a pivotal role in maintaining the mucosal integrity of the stomach after injury. In the present study, we evaluated the mucosal ulcerogenic and mucosal blood flow (GMBF) responses in the stomach after damage by taurocholate (TC) in knockout mice lacking EP1 or EP3 receptors.

Methods:

Under urethane anaesthesia, a mouse stomach was mounted in an ex vivo chamber, exposed to 20 mmol/L TC for 20 min and treated with 20 mmol/L HCl before and after TC. GMBF was measured with a laser Doppler flowmeter.

Results:

Mucosal exposure to TC in wild‐type mice caused a marked decrease in potential difference (PD), followed by an increase in H+ loss and GMBF. The decreased PD was gradually normalized after removal of TC from the chamber, with minimal damage in the mucosa 1 h after TC treatment. This hyperaemic response was inhibited by indomethacin, resulting in severe lesions in the mucosa without any change in PD or H+ loss. None of these responses induced by TC were altered in EP3−/− mice. However, in mice lacking EP1 receptors, TC treatment did not increase GMBF, despite causing PD reduction and acid loss, and resulted in severe damage in the mucosa. These responses were closely similar to those observed in animals pretreated with ONO‐8711, a EP1 receptor antagonist. Mucosal PGE2 content was significantly increased after TC, similarly in all groups of mice.

Conclusion:

These results confirm a mediator role for PGE2 in gastric hyperaemic response following mucosal exposure to TC and suggest that endogenous PGs may contribute to maintaining mucosal integrity after barrier disruption, mainly through activation of the EP1 receptor subtype.
Up‐regulation of COX‐2 by inhibition of COX‐1 in the rat: a key to NSAID‐induced gastric injury
Authors: Tanaka A. , Araki H. , Hase S. , Komoike Y. , Takeuchi K.
Published: March 2003

Background:

A recent study demonstrated that inhibition of both cyclooxygenase (COX)‐1 and COX‐2 is required for the development of nonsteroidal anti‐inflammatory drug (NSAID)‐induced gastric lesions. However, the role of COX‐1 or COX‐2 inhibition in the pathogenisis of these lesions remains unclear.

Aim:

To examine the gastric ulcerogenic properties of selective COX‐1 and COX‐2 inhibitors in rats and to investigate further the relationship of COX inhibition to various events involved in the process of NSAID‐induced gastric lesions.

Methods:

Animals were given various COX inhibitors p.o., either alone or in combination, and killed 8 h later. Under the treatment, gastric damage, prostaglandin (PG) E2 content, mucosal permeability, myeloperoxidase (MPO) activity as well as gastric motility were examined.

Results:

The nonselective COX inhibitor indomethacin inhibited PGE2 production, enhanced gastric motility, and provoked severe lesions in the stomach, with an increase in mucosal permeability and MPO activity. In contrast, the selective COX‐2 inhibitor rofecoxib did not induce any damage in the stomach and had no effect on mucosal PGE2 content. Similarly, the selective COX‐1 inhibitor SC‐560 also caused no gastric damage, despite inhibiting PGE2 production. The combined administration of SC‐560 and rofecoxib, however, provoked gross damage in the gastric mucosa, in a dose‐dependent manner for each drug. SC‐560, but not rofecoxib, caused marked gastric hypermotility and an increase in mucosal permeability, although an increase in MPO activity was observed only when rofecoxib was coadministered. The normal gastric mucosa expressed COX‐1 mRNA and not COX‐2 mRNA, but COX‐2 mRNA was expressed in the stomach after administration of SC‐560 as well as indomethacin but not rofecoxib.

Conclusion:

These results suggest that the gastric ulcerogenic properties of NSAIDs are not accounted for solely by COX‐1 inhibition, but require the inhibition of both COX‐1 and COX‐2. The inhibition of COX‐1 up‐ regulates COX‐2 expression, and COX‐2/PGs may, in turn, counteract the deleterious affects of gastric hypermotility due to COX‐1 inhibition.
Role of elastase and active oxygen species in gastric mucosal injury induced by aspirin administration in Helicobacter pylori‐infected Mongolian gerbils
Authors: Yoshida N. , Sugimoto N. , Ochiai J. , Nakamura Y. , Ichikawa H. , Naito Y. , Yoshikawa T.
Published: March 2003

Background:

H. pylori infection potentiates aspirin‐induced gastric mucosal injury by mechanisms that include accumulation of activated neutrophils.

Aim:

To determine the role of elastase and active oxygen species (AOS) produced by activated neutrophils in the gastric mucosal injury induced by administration of acidified aspirin to H. pylori‐infected Mongolian gerbils.

Methods:

H. pylori ATCC43504 culture broth was administered by oral gavage to male Mongolian gerbils at 7 weeks of age. After 4 weeks, acidified aspirin (400 mg/kg) was administered orally, and 3 h later, the total area of gastric erosions, myeloperoxidase (MPO) activity (an index of neutrophil accumulation), thiobarbituric acid‐reactive substances (TBARS, an index of lipid peroxidation), and KC/GRO (a chemo‐attractive cytokine in rodents) were measured in gastric mucosa. To determine the role of elastase or AOS derived from neutrophils in these circumstances, ONO‐5046 (an elastase inhibitor), a combination of superoxide dismutase (SOD) and catalase (scavengers of AOS), and polaprezinc (an anti‐ulcer agent with anti‐inflammatory effects) were administered before aspirin.

Results:

ONO‐5046 inhibited the increase in gastric erosions and mucosal TBARS induced by administration of aspirin to H. pylori‐infected gerbils, but not the increases in MPO activity or KC/GRO contents. A combination of SOD and catalase or polaprezinc significantly reduced gastric erosions, TBARS concentrations, MPO activity and KC/GRO concentration.

Conclusions:

These results suggest that neutrophil‐derived‐elastase and ‐oxidants play an important role in the gastric mucosal injury induced by administration of aspirin to H. pylori‐infected gerbils.
Screening of gene expression profiles in gastric epithelial cells induced by Helicobacter pylori using microarray analysis
Authors: Sepulveda A. R. , Tao H. , Carloni E. , Sepulveda J. , Graham D. Y. , Peterson L. E.
Published: March 2003

Background:

H. pylori infection is a major risk factor in gastric cancer development. The availability of cDNA microarrays creates the unprecedented opportunity to examine simultaneously dynamic changes of multiple pathways affected by H. pylori infection.

Aim:

In this study we examined broad patterns of gene expression induced by H. pylori in the gastric cancer cell line 1739‐CRL AGS cells in culture using the U95A microarray.

Methods:

H. pylori were cocultured with AGS cells for 4, 12, 24 and 48 h. Total RNA was extracted and after labelling was used for detection of genes represented in the human U95A microarray set. Data analyses were performed using GeneChip and CLUSFAVOR software.

Results:

Nearly 6000 genes present in the array were expressed by AGS cells. We report approximately 200 genes that showed the most marked changes. Our studies confirm the up‐regulation of c‐jun, jun‐B, c‐fos and cyclin D1 by H. pylori. We report for the first time the induction of the serine threonine kinase pim‐1 and ATF3 by H. pylori infection of AGS cells.

Conclusions:

In this microarray analysis of gene expression induced by H. pylori in gastric epithelial cells, we identified a large number of unsuspected genes affected by H. pylori. Further, we show that unsupervised hierarchical cluster analysis can provide useful insight into the possible contribution of genes in specific pathways, based on their profile of expression.
Helicobacter pylori and clinical risks—focus on gastro‐oesophageal reflux disease
Authors: Malfertheiner P. , O'Connor H. J. , Genta R. M. , Unge P. , Axon A. T. R.
Published: March 2003

Helicobacter pylori is a gastric pathogen that is a major cause of peptic ulcer disease, has a role in mucosa‐associated lymphoid tissue (MALT) lymphoma and is associated with gastric cancer. Yet, in a large proportion of the human population, H. pylori infection has no apparent adverse clinical consequences. Furthermore, recent research suggests that H. pylori may even confer protection against gastroesophageal reflux disease.

The conflicting evidence surrounding H. pylori infection was discussed at a sponsored symposium in Helsinki, introduced by Professor P. Malfertheiner, with papers presented by Dr H. J. O'Connor, Professor R. M. Genta, Dr P. Unge and Professor A. T. R. Axon. Emerging epidemiological and retrospective evidence suggests that the presence of H. pylori infection may provide some protection against gastroesophageal reflux disease, but there is other evidence that shows no benefit of H. pylori for the protection of the oesophagus. It was felt that prospective, multicentre studies are needed to explore the H. pylori–gastroesophageal disease relationship further, to avoid confusing potential benefits with known risks.

Following the symposium, a discussion on the relative risks and benefits for H. pylori eradication was provided by Professor Axon and Professor Blaser.

Eradication of H. pylori has been recommended in a series of management guidelines issued by consensus groups. However, accurate estimates of the relative risks and benefits of H. pylori infection in the general population, as well as in specific patient groups, is essential in order to develop a management strategy.
After gastritis – an imaginary journey into a Helicobacter‐free world
Authors: Genta R. M.
Published: March 2003

This article explores the consequences of the world‐wide trend that may result – at different times for different populations – in the disappearance of Helicobacter pylori and gastritis. After a brief historical introduction, some of the factors that contribute to the decrease in the prevalence of H. pylori are presented. The most apparent results of this trend in the industrialized world have been a decrease in the incidence of peptic ulcer and distal gastric adenocarcinoma. However, some other conditions of the upper digestive tract, such as acid reflux disease and adenocarcinoma of the cardio‐oesophageal junction have been increasing. This simultaneous increase has led to the speculation that it may be causally related to the decreased prevalence of gastritis, and currents of thought supporting a laissez faire attitude with regards to H. pylori infection have developed. If these trends continue, future research aimed at understanding the pathogenesis of H. pylori‐related conditions, including gastric carcinogenesis, will hinge on access to populations in which H. pylori is still highly prevalent, and on further refinement of the recently introduced Mongolian gerbil model.
Cost‐effectiveness of different GERD management strategies
Authors: Vakil N.
Published: March 2003

Recent data on gastro‐oesophageal reflux disease management strategies suggest that the indirect costs of reflux disease are high, and that inadequate treatment is associated with significant out‐patient costs for patients. Long‐term management strategies now focus on discontinuous therapy for some subgroups of patients. On‐demand therapy is particularly attractive for patients who have no mucosal disease.
Ulcerative colitis – surgical indications and treatment
Authors: Nicholls R. J.
Published: March 2003

The indication for surgery is a balance between the severity of the disease despite full medical treatment and the potential disadvantages of surgery. The decision requires cooperation between gastroenterologist and surgeon.

Colectomy with ileostomy and preservation of the rectum in the emergency setting is the accepted procedure and can rapidly restore the patient to normal health allowing withdrawal of anti‐inflammatory medication. After recovery all surgical possibilities are then open for the future.

The elective indications for surgery include failure of medical treatment, retardation of growth in a child or adolescent and neoplastic transformation. The choice of operation includes conventional proctocolectomy, restorative proctocolectomy (RPC) and colectomy with ileo‐rectal anastomosis. Each has relative advantages and disadvantages. RPC is the commonest procedure. It offers a satisfactory outcome in 70–90% of patients with a cumulative failure rate of 10–15% over a 10 year period.

Causes of failure include sepsis (50%), dysfunction (30%) and pouchitis (10%). In selected cases salvage surgery to avoid failure can be successful with rates of around 70% for outlet obstruction and fistulation and 50% for pelvic sepsis.
The management of refractory Crohn's disease
Authors: Rizzello F. , Gionchetti P. , Venturi A. , Morselli C. , Campieri M.
Published: March 2003

Refractoriness to conventional therapy is a common and intriguing problem in Crohn's disease patients. At the present time there is no agreement on its definition and several mechanisms are involved in its determination. Immunosuppressors, such as azathioprine (AZA), 6‐mercaptopurine (6MP) and methotrexate (MTX) are effective drugs for controlling the inflammatory process and avoid chronic glucocorticosteroid treatment and its related related side‐effects. Recently, the introduction of tumour necrosis factor antibodies (infliximab) has dramatically changed the natural history of Crohn's disease and its therapeutic approach. Several studies have determined the efficacy, mechanisms and safety of infliximab. However, this molecular approach has also left several questions unanswered about the mechanisms of refractoriness, possible concomitant treatments and long‐term safety and efficacy.
Review article: albumin as a drug—biological effects of albumin unrelated to oncotic pressure
Authors: Evans T. W.
Published: March 2003

Albumin is the main determinant of plasma oncotic pressure and it plays a pivotal role in modulating the distribution of fluids between compartments. Moreover, it has many other biological properties which may be important not only for its physiological actions but also for its therapeutic effects. Among the non‐oncotic properties are its capacity of molecule transportation and free radical scavenging, its ability to modulate capillar permeability, neutrophil adhesion and activation and its haemostatic effects. The following article reviews these biological effects as well as its structure, synthesis, catabolism and distribution.
Meta‐analysis of somatostatin, octreotide and gabexate mesilate in the therapy of acute pancreatitis
Authors: Andriulli  , Leandro  , Clemente  , Festa  , Caruso  , Annese  , Lezzi  , Lichino  , Bruno  , Perri
Published: March 2003

Background:

Autodigestion of the pancreas, secondary to the activation of digestive enzymes, is the pathogenetic mechanism of acute pancreatitis (AP).

Aim:

Clinical trials in which somatostatin (SS), octreotide (OCT) and gabexate mesilate (FOY) were used to treat patients with AP, were submitted to a meta‐analytical evaluation. Five end‐points were evaluated: early and overall mortality, patients with complications, complication rate, and patients who needed surgery.

Results:

In mild AP, no agent proved of value. In severe AP, both SS and OCT were beneficial in improving the overall mortality: the odds ratios (OR) were, respectively, 0.36 (95% CI: 0.20–0.64, P = 0.001) and 0.57 (95% CI: 0.35–0.88, P = 0.006). FOY had no effect on either early or overall mortality, but was effective in improving complication rate (OR = 0.70, 95% CI: 0.56–0.88, P = 0.02), number of patients with complications (OR = 0.61, 95% CI: 0.41–0.91, P = 0.01), and number of cases submitted to surgery (OR = 0.60, 95% CI: 0.39–0.92, P = 0.01). SS and OCT had no effect on these latter outcomes.

Conclusions:

Antisecretory agents, such as SS and OCT, are able to reduce mortality without affecting complications, whereas antiproteases, such as FOY, have no effect on mortality but do reduce complications. A trial exploring the efficacy of combining antisecretory agents with antiproteases would be of great benefit in patients with severe AP.
The role of osmolality in the absorption of a nutrient solution
Authors: Pfeiffer  , Schmidt  , Kaess
Published: March 2003

Background:

Loss of water during enteral nutrition following massive intestinal resection may be severe. Low osmolality of oral rehydration solutions has recently been shown to mediate an increase in water absorption.

Aim:

To evaluate the effect of osmolality of a nutrient solution on the intraluminal duodenojejunal water flow, and the net absorption rates of total nitrogen and carbohydrate.

Methods:

Eight healthy volunteers with a mean age of 27 (range 25–29) years participated in the study. Enteral nutrition (17% protein, 59% carbohydrate, 24% lipid plus 5 g/L PEG 4000) was infused (5 mL/min 2.64 kcal/min) into the descending duodenum either as a hypotonic (160 mOsmol/kg) or as an isotonic solution in a random order. Intestinal samples were aspirated 20 and 45 cm distally to the infusion point.

Results:

Intraluminal water flow rates were significantly lower with the hypotonic solution than with the isotonic solution, both in the duodenum (4.9 ± 0.3 vs. 6.7 ± 0.5 mL/min; P < 0.02) and the upper jejunum (3.0 ± 0.1 vs. 3.9 ± 0.2 mL/min; P < 0.005). The net absorption rates of total nitrogen and carbohydrate were similar with both solutions.

Conclusion:

Low osmolality of a nutrient solution decreases intraluminal water flow rates in the upper intestine without affecting the absorption rates of total nitrogen and carbohydrate. Compared with an isotonic solution, the use of a hypotonic solution might lower the water loss in patients with extensive short bowel intestinal resection.
Nizatidine in combination with amoxycillin and clarithromycin in the treatment of Helicobacter pylori infection
Authors: Talley  , Full‐Young  , Wyatt  , Adams  , Lau  , Borody  , Tseng‐Shing  , Daskolopolos  , Cheung  , Talley
Published: March 2003

Background:

The efficacy of H2‐antagonists in combination with antibiotics in curing Helicobacter pylori infection remains controversial, and it is uncertain whether double dose H2‐antagonist therapy is superior to standard dose.

Aim:

To determine the efficacy of two doses of nizatidine in combination with two antibiotics in the treatment of H. pylori.

Methods:

A randomized controlled trial was conducted in 160 patients comparing nizatidine l50 mg with 300 mg b.d. (standard vs. double dose), in combination with clarithromycin (500 mg) and amoxycillin (1000 mg) b.d. for 14 days, in Australia and Taiwan. Compliance was based on a clinical assessment and pill count. H. pylori status was determined by histology (antrum and corpus) and CLO‐test.

Results:

Baseline clinical and endoscopic findings were similar in both arms of the study. Based on an intention‐to‐treat analysis, cure of H. pylori was achieved in 78% (95% CI: 70.4–85.4%) in the standard nizatidine dose arm and 70% (95% CI: 61.6–78.2%) in the double dose arm (P = 0.2). Similar cure rates were observed in ulcer and non‐ulcer patient groups. Compliance was excellent in the single and double dose arms (85 and 91%, respectively).

Conclusions:

The combination of nizatidine in standard or double dose with clarithromycin and amoxycillin is similarly efficacious in curing H. pylori infection.
Evaluation of short‐term low‐dose triple therapy for the eradication of Helicobacter pylori by factorial design in a randomized, double‐blind, controlled study
Authors: Bazzoli  , Zagari  , Pozzato  , Varoli  , Fossi  , Ricciardiello  , Alampi  , Nicolini  , Sottili  , Simoni  , Roda  , Roda
Published: March 2003

Background

Studies demonstrating the efficacy of short‐term low‐dose triple therapies including omeprazole (O), clarithromycin (C) and a nitroimidazole (tinidazole, T) for Helicobacter pylori eradication have largely been open and uncontrolled, and have not assessed antibiotic sensitivity. Simpler regimens using the component drugs have not been evaluated.

Aim

To evaluate the OCT regimen in a randomized, controlled trial, testing for pre‐ and post‐treatment antibiotic resistance and comparing, in a factorial design, the OCT regimen with simpler combinations of its components.

Methods

One hundred and twenty‐eight patients (68 males, 60 females, age 22–80 years, mean 53 years) with H. pylori gastritis were randomly assigned to one of the following four treatment groups: (C) clarithromycin 250 mg b.d.; (OC) omeprazole 20 mg o.d. + clari‐thromycin 250 mg b.d.; (CT) clarithromycin 250 mg b.d. + tinidazole 500 mg b.d.; (OCT) omeprazole 20 mg q.d.s. + clarithromycin 250 mg b.d. + tinidazole 500 mg b.d. The drugs were administered for 1 week. Medical interview, upper gastrointestinal endoscopy (with four antral and four corpus biopsies) and the 13C‐urea breath test were carried out for all patients prior to and 4 weeks after treatment. Biopsy specimens were used for the urease test, histology, and culture and sensitivities.

Results

All but one patient completed treatment. Side‐effects were rare and mild in all groups. The eradication rate was 93.8% in group OCT, 59.4% in group CT, 31.3% in group OC and 6.3% in group C. Pre‐treatment metronidazole resistance was 12.8%, clarithromycin 1.1% and, to both antibiotics, 2.1%. In patients with pre‐treatment metronidazole resistance, the eradication rate was 75% in group OCT and 33% in group CT. Post‐treatment resistance to clarithromycin was induced in 28.5% of the failures in group C, but in none of group OC. Resistance to both antibiotics occurred in 22.2% of the failures in group CT and in none of group OCT.

Conclusions

(i) The high efficacy of the OCT regimen is proved and each of the individual components of the regimen is essential to the result, possibly via a synergistic effect. (ii) Pre‐treatment metronidazole resistance is scarcely relevant to the outcome. (iii) Acquired resistance is essentially nil if omeprazole is part of the regimen.
Efficacy and safety of three 7‐day Helicobacter pylori eradication regimens containing ranitidine bismuth citrate
Authors: Ricciardiello  , Cannizzaro  , D’angelo  , Ederle  , Gerace  , Iaquinto  , Reina  , Scarpulla  , Spadaccini  , Olivieri  , Tosatto  , Fossi  , Pozzato  , Zagari  , Bazzoli  , Roda
Published: March 2003

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.
Two‐week course of pantoprazole combined with 1 week of amoxycillin and clarithromycin is effective in Helicobacter pylori eradication and duodenal ulcer healing
Authors: Louw  , Rensburg  , Hanslo  , Grundling H. DeK. , Girdwood  , Marks
Published: March 2003

Background:

Experience with proton pump inhibitor‐based triple therapy is predominantly with omeprazole‐containing regimens.

Aim:

To investigate the efficacy of a pantoprazole‐based regimen, with either a 1 or 2‐week course of antibiotic co‐therapy, in eradicating H. pylori, healing duodenal ulcers and to assess the antibiotic sensitivity profiles of isolated H. pylori strains.

Methods:

A single‐blind, multicentre, parallel group comparison of patients with endoscopically proven, H.␣pylori associated, active duodenal ulceration. All patients received pantoprazole, 40 mg b.d. for 2 weeks. Patients were randomized to receive either 1 or 2 weeks of therapy with amoxycillin, 1 g b.d. and clarithromycin 500 mg b.d. Patients were endoscoped at entry, at 14 days and a minimum of 4 weeks after cessation of all therapy. H. pylori status was determined by urease reaction, histological assessment and culture from antral and body biopsies. Antibiotic sensitivity was determined using the agar dilution technique.

Results:

Sixty‐seven patients were randomized. One week co‐therapy (n = 33): eradication efficacy, ITT = 79% (95% CI: 61–91%); ulcer healing efficacy (at 6‐week visit) = 88% (95% CI: 72–97%). Two‐week co‐therapy (n = 34): eradication efficacy, ITT = 91% (95% CI: 76–98%; ulcer healing efficacy = 88% (95% CI: 73–97%). Both regimens were well tolerated and no primary antibiotic resistance was noted.

Conclusion:

Pantoprazole‐based triple therapy, with either 1 or 2 weeks of co‐therapy with amoxycillin and clarithromycin, is effective in eradicating H. pylori and healing duodenal ulceration.
Review article: the diagnosis and treatment of haematinic deficiency in gastrointestinal disease
Authors: Pawson  , Mehta
Published: March 2003

Deficiency of any of the vitamins and minerals essential for normal erythropoiesis (haematinics), including iron, copper, cobalt, vitamins A, B12, B6, C, E, folic acid, riboflavin and nicotinic acid, may be associated with defective erythropoiesis and anaemia. Iron, vitamin B12 and folate are the haematinics for which deficiency states manifest most often clinically and are the focus of this review. The normal absorption of these haematinics and gastrointestinal causes of their deficiency are described. Investigations, including the use of homocysteine metabolite levels and new techniques such as serum transferrin receptor assays, and treatment of haematinic deficiency are discussed in detail.
The effect of healing oesophagitis on oesophageal motor function as determined by oesophageal scintigraphy and ambulatory oesophageal motility/pH monitoring
Authors: Dougall N. I. M C , Mooney R. B. , Ferguson W. R. , Collins J. S. A. , Mcfarland R. J. , Love A. H. G.
Published: March 2003

Background:

Oesophagitis has been shown by standard manometry to be associated with impaired oesophageal motility, but it remains unclear if this abnormality improves with healing of oesophagitis.

Aim:

To determine if healing of oesophagitis improves oesophageal motility using solid bolus oesophageal transit scintigraphy and combined ambulatory oesophageal motility/pH monitoring.

Methods:

Patients with grade II–III oesophagitis underwent ambulatory motility/pH monitoring (using a Konigsberg catheter with four pressure transducers at 5 cm intervals) and solid bolus scintigraphy before and after treatment with omeprazole 20 mg b.d. for 8–14 weeks.

Results:

Three (11%) of the 28 patients failed to heal. Initial scintigraphy was abnormal in 18 (67%) of 27 patients (one refused scintigraphy). Twenty‐three of the 25 healed patients had repeat studies showing no significant change in the number which were abnormal (16 (64%), P = 1.0) or the overall oesophageal transit time (P = 0.65). Due to intolerance of the technique, only 11 patients had ambulatory motility/pH performed both before and after healing, giving the study 90% power to detect a 5 mmHg increase in peristaltic amplitude. No significant improvement was seen in any motility or pH parameter after healing of oesophagitis.

Conclusion:

Analysis of oesophageal motility showed no improvement in peristaltic activity after healing of oesophagitis, suggesting that the abnormal motility is either a primary disorder or an irreversible consequence of mucosal damage.
Comparison of 24‐h control of gastric acidity by three different dosages of pantoprazole in patients with duodenal ulcer
Authors: Savarino  , Mela  , Zentilin  , Bisso  , Pivari  , Vigneri  , Termini  , Fiorucci  , Usai  , Malesci  , Celle
Published: March 2003

Background

It is now clear that the extent to which gastric acid secretion must be suppressed varies with the clinical condition being treated.

Aim

To assess the 24‐h control of gastric acidity and the individual response variability of three different doses of pantoprazole.

Methods

Sixty‐four duodenal ulcer patients were recruited for this prospective, randomized, multicentre, double‐blind, parallel‐group study. They were subdivided into three well‐matched groups treated with 20 mg o.m., 40 mg o.m. and 40 mg b.d. of pantoprazole, respectively. Endoscopy and intragastric pH monitoring were performed in each patient before and after 14 days of treatment.

Results

Fifty‐five patients were eligible for final analysis (17 treated with 20 mg o.m., 18 with 40 mg o.m. and 20 with 40 mg b.d. pantoprazole). The ulcer crater healed in 94, 88 and 95% of cases, respectively. The three dosages of pantoprazole produced significant increases in gastric pH compared to basal levels (P < 0.0001). There was also a clear dose‐dependent pharmacodynamic effect, which augmented on moving from the lowest dosage of 20 mg o.m. pantoprazole to the highest dosage of 40 mg b.d. (P < 0.01–0.001). The inter‐individual response variability within the three treatment groups was more marked with the dose of 20 mg than with the two higher doses of pantoprazole.

Conclusions

All three doses of pantoprazole we tested are highly effective in decreasing gastric acidity and there is a clear dose‐dependent pharmacodynamic effect on moving from the lowest to the highest dosage. The greatest inter individual variation in the degree of acid inhibition was seen with pantoprazole 20 mg o.m., while the majority of patients responded adequately to the two higher doses of the drug.
A placebo‐controlled trial to assess the effects of 8 days of dosing with rabeprazole versus omeprazole on 24‐h intragastric acidity and plasma gastrin concentrations in young healthy male subjects
Authors: Williams  , Sercombe  , Hamilton  , Pounder
Published: March 2003

Background:

Rabeprazole (LY307640, E3810) is a new, potent, proton pump inhibitor. A single daily 20 mg dose significantly decreases 24‐h intragastric acidity. There are no data currently available directly comparing the effect of rabeprazole on 24‐h acidity with established proton pump inhibitors.

Aim:

To compare the effects of rabeprazole 20 mg o.m. and omeprazole 20 mg o.m. on 24‐h intragastric acidity and plasma gastrin concentration in a randomized, double‐blind, placebo‐controlled trial, in healthy H. pylori‐negative subjects.

Methods:

Twenty‐four healthy male volunteers, negative for H. pylori infection by serology and 13C‐urea breath test, were studied on the 1st and 8th day of dosing with either placebo, rabeprazole 20 mg or omeprazole 20 mg, once each morning, in a crossover fashion. On days 1 and 8, hourly intragastric acidity was measured by gastric aspiration for 24 h from 08.00 hours. On day 8, plasma gastrin concentrations were also measured hourly from 08.00 to 24.00 hours, then every 2 h thereafter.

Results:

A single dose of both rabeprazole and omeprazole significantly decreased 24‐h intragastric acidity compared with placebo. The 24‐h acidity on day 1 was significantly decreased for rabeprazole compared with omeprazole (331 vs. 640 mmol.h/L, P < 0.001), resulting in a significantly higher median 24‐h intragastric pH and longer times at which intragastric pH was>  3 and>  4. On day 8 of dosing, the decrease in 24‐h intragastric acidity was greater with rabeprazole than with omeprazole, but the difference was not statistically significant (160 vs. 218 mmol.h/L, P = 0.1). However, 24‐h plasma gastrin concentration (1687 vs. 1085 pmol.h/L, P < 0.01) and percentage time that intragastric pH was>  3 (69 vs. 59%, P = 0.008) and>  4 (60 vs. 51%, P = 0.03) were significantly greater.

Conclusions:

Rabeprazole 20 mg once daily has a significantly faster onset of antisecretory activity than omeprazole 20 mg once daily. After 8 days the differences in intragastric pH > 3 and>  4 holding times persisted, but there was no significant difference in 24‐h acidity.