Somatostatin and the gastrointestinal tract

Emerging pharmacological targets for alcohol use disorder

Alcohol Use Disorder (AUD) remains a challenging condition with limited effective treatment options; however new technology in drug delivery and advancements in pharmacology have paved the way for discovery of novel therapeutic targets. This review explores emerging pharmacological targets that offer new options for the management of AUD, focusing on the potential of somatostatin (SST), vasoactive intestinal peptide (VIP), glucagon-like peptide-1 (GLP-1), nociceptin (NOP), and neuropeptide S (NPS). These targets have been selected based on recent advancements in preclinical and clinical research, which suggest their significant roles in modulating alcohol consumption and related behaviors. SST dampens cortical circuits, and targeting both the SST neurons and the SST peptide itself presents promise for treating AUD and various related comorbidities. VIP neurons are modulated by alcohol and targeting the VIP system presents an unexplored avenue for addressing alcohol exposure at various stages of development. GLP-1 interacts with the dopaminergic reward system and reduces alcohol intake. Nociceptin modulates mesolimbic circuitry and agonism and antagonism of nociceptin receptor offers a complex but promising approach to reducing alcohol consumption. NPS stands out for its anxiolytic-like effects, particularly relevant for the anxiety associated with AUD. This review aims to synthesize the current understanding of these targets, highlighting their potential in developing more effective and personalized AUD therapies, and underscores the importance of continued research in identifying and validating novel targets for treatment of AUD and comorbid conditions.

Clinical trial: The effectiveness of long-acting somatostatin analogue for output reduction of high-output intestinal fistula or small bowel enterostomy. A randomised controlled trial

BACKGROUND

High-output intestinal fistulas and small bowel enterostomies are associated with morbidity and mortality. Current standard treatment for output reduction consists of fluid and dietary restrictions and medical therapy. There is conflicting evidence regarding the use of somatostatin analogues for output reduction.

AIM

The aim of this study is to investigate whether lanreotide, added to current standard treatment, further reduces intestinal output in patients with high-output fistulas and enterostomies.

METHODS

This was an open-label, multicentre, randomised controlled trial. Adult patients with a high-output intestinal fistula (>500 mL/24 h) or small bowel enterostomy (>1500 mL/24 h) more than 4 weeks post-surgery and receiving standard medical treatment (dietary- and fluid restriction, PPI, loperamide and codeine) for at least 2 weeks were eligible for inclusion. We randomised patients 1:1 between continuing standard treatment (control), and subcutaneous lanreotide 120 mg every 4 weeks with standard treatment. The primary outcome was the number of responders, with response defined as an output reduction of ≥25%, 8 weeks after randomisation. We also investigated the proportional change in output.

RESULTS

We randomised 40 patients; 17 had a fistula and 23 a small bowel enterostomy. There were 9/20 responders in the intervention group and 2/20 in the control group (p = 0.013). The proportional output reduction was -26% (IQR -4 to -38) in the intervention group, compared to an increase of 4% (IQR 20 to -13) in the control group (p = 0.004).

CONCLUSIONS

In patients with a high-output fistula or small bowel enterostomy, addition of lanreotide to current standard treatment can provide a clinically relevant output reduction.

TRIAL REGISTRATION

EudraCT: 2013-003998-10.

The Silent Spill: A Case Report on Navigating the Challenges of a Chyle Leak

A chyle leak occurs due to a discontinuity in the thoracic duct. It is a very rare condition that occurs as a result of injuries or surgical procedures. Chyle is rich in antibodies. Its functions are to maintain the equilibrium of the human fluid system, draw in fatty acids, and maintain the natural immunity of humans. It is identified by the increased quantity of drains, which show a milky white color and clinically palpable supraclavicular collection. It is a condition that has to be managed as soon as possible as it leads to serious nutritional debridement, electrolyte imbalance, and complications such as chylothorax and chylomediastinum. It is managed by various surgical and conservative approaches, such as ligating the thoracic duct, using sclerosing agents, giving total parenteral nutrition, and restricting physical activities, as discussed in this article.

GPR84 in physiology-Many functions in many tissues

Members of the GPCR superfamily have a wide variety of physiological roles and are therefore valuable targets for developing effective medicines. However, within this superfamily are receptors that are less well characterized and remain orphans, including GPR84. This receptor is stimulated by ligands derived from dietary nutrients, specifically medium chain fatty acids (C9-14), and novel synthetic agonists. There are data demonstrating the role of GPR84 in inflammatory pathways, in addition to emerging data suggesting a key role for GPR84 as a nutrient-sensing GPCR involved in metabolism by sensing energy load via nutrient exposure and subsequent signalling leading to modulation of food intake. Exploring GPR84 pharmacology, its localization and what drives its expression has revealed multiple roles for this receptor. Here, we will reflect on these various roles of GRP84 demonstrated thus far, primarily by exploring data from pre-clinical and clinical studies in various physiological systems, with a specific focus on the gastrointestinal tract. LINKED ARTICLES: This article is part of a themed issue GPR84 Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.10/issuetoc.

Effect of postoperative utilization of somatostatin on clinical outcome after definitive surgery for duodenal fistula

PURPOSE

To evaluate the effect of postoperative utilization of somatostatin after definitive surgery for duodenal fistula (DF) in preventing a recurrence.

METHODS

Patients with definitive surgery for DF between January 2010 and December 2021 were categorized based on the utilization of somatostatin or not after the surgery. Patients in the Somatostatin group were matched to those in the Non-somatostatin group using propensity scores matching (PSM), so as to evaluate the effect of postoperative use of somatostatin by comparing the two groups.

RESULTS

A total of 154 patients were divided into the in the Somatostatin group (84) and the Non-somatostatin group (70). Forty-three patients (27.9%) exhibited a recurrent fistula, with which the postoperative use of somatostatin was not associated (19 [22.6%] in the Somatostatin group and 24 (34.3%) in the Non-somatostatin group; unadjusted OR 0.56; 95% CI 0.28-1.14; P = 0.11). However, the postoperative usage of somatostatin served as a protective factor for developing into high-output recurrent fistula (eight (13.3%) in the Somatostatin group and 15 (25%) in the Non-somatostatin group; adjusted OR 0.39; 95% CI 0.15-0.93; P = 0.04). After PSM, the recurrent fistula occurred in 29.2% subjects (35/120). The postoperative usage of somatostatin was not associated with recurrent fistula (13 in PSM Somatostatin group vs. 22 in PSM Non-somatostatin group; unadjusted OR 0.48; 95% CI 0.21-1.07; P = 0.07), while its postoperative usage decreased the incidence of recurrent high-output fistula (5/60 in the PSM Somatostatin group, compared with 13/60 in the PSM Non-somatostatin group; adjusted OR 0.30; 95% CI 0.09-0.95).

CONCLUSION

Postoperative use of somatostatin could effectively reduce the incidence of recurrent high-output fistula, without association with overall incidence of postoperative recurrent fistula.

Knock-in mouse models for studying somatostatin and cholecystokinin expressing cells

BACKGROUND

Somatostatin (SST) and cholecystokinin (CCK) are peptide hormones that regulate the endocrine system, cell proliferation and neurotransmission.

NEW METHOD

We utilized the novel Easi-CRISPR system to generate two knock-in mouse strains with Cre recombinase in SST- and CCK-expressing cells and validated their utility in the developing and adult brain tissues.

RESULTS

The full nomenclature for the newly generated strains are C57BL/6-Sst^{em1(P2A-iCre-T2A-mCherry)Mirn} and C57BL/6-Cck^{em1(iCre-T2A-mCherry-P2A)Mirn}. For the Sst locus, a P2A-iCre-T2A-mCherry cassette was inserted immediately upstream of the stop codon (C terminus fusion). For the Cck locus, iCre-P2A-mCherry-T2A cassette was inserted at the start codon (N terminus fusion). Knock-in mice were generated using the Easi-CRISPR method. Developmental and adult SST and CCK expressions were preserved and showed an appropriate expression pattern in both models, with an active fluorescent tag in both animal lines.

COMPARISON WITH EXISTING METHODS

Knock-in mouse models to study cell types that produce these critically important molecules are limited to date. The knock-in mice we generated can be used as reporters to study development, physiology, or pathophysiology of SST and CCK expressing cells - without interference with native expression of SST and CCK. In addition, they can be used as Cre driver models to conditionally delete floxed genes in SST and CCK expressing cells across various tissues.

CONCLUSIONS

These two mouse models serve as valuable tools for in vitro and in vivo research studies related to SST and CCK biology across the lifespan and across different tissue types.

Role of octreotide in small bowel bleeding

Gastrointestinal bleeding accounts for a drastic negative impact on the quality of the patients’ lives as it requires multiple diagnostic and therapeutic interventions to identify the source of the bleeding. Small bowel bleeding is the least common cause of gastrointestinal bleeding. However, it is responsible for the majority of complaints from patients with persisting or recurring bleeding where the primary source of bleeding cannot be identified despite investigation. A somatostatin analog known as octreotide is among the medical treatment modalities currently used to manage small bowel bleeding. This medication helps control symptoms of gastrointestinal bleeding by augmenting platelet aggregation, decreasing splanchnic blood flow, and antagonizing angiogenesis. In this review article, we will highlight the clinical efficacy of octreotide in small bowel bleeding and its subsequent effect on morbidity and mortality.

Comparison Between Intravenous and Intramuscular Octreotide in the Management of Heyde’s Syndrome

Heyde’s syndrome is defined as a triad of aortic stenosis, anemia due to angiodysplasia-related bleeding, and von Willebrand syndrome type 2A. It is a rare disease and a diagnostic challenge. Treatment modalities include symptomatic management, blood transfusions, aortic valve replacement, and medications such as octreotide. Here, we report the case of a patient who was resistant to symptomatic management, aortic valve replacement, as well as intravenous octreotide.

Identification of SSTR5 Gene Polymorphisms and Their Association With Growth Traits in Hulun Buir Sheep

The aim of this study was to locate SSTR5 polymorphisms and evaluate their association with growth traits in Hulun Buir sheep. The study followed up 884 Hulun Buir sheep from birth to 16 months of age, which were born in the same pasture and the same year, and a consistent grazing management strategy was maintained. The birth weight (BRW) was recorded at birth, and body weight (BW), body height (BH), body length (BL), chest circumference (ChC), chest depth (ChD), chest width (ChW), hip width (HW), and cannon circumference (CaC) were measured at 4 and 9 months of age. BW, BH, BL, ChD, HW, and CaC were also recorded at 16 months of age. Based on the growth traits, 233 sheep were selected as experimental animals. Sanger sequencing was performed, and seven single-nucleotide polymorphisms (SNPs) were identified. Association analyses of the SNPs and the growth traits were then conducted. Seven SNPs of the SSTR5 exhibited moderate polymorphism (0.25 Collapse

Key Words

• Hulun Buir sheep
• SSTR5
• association
• growth traits
• haplotypes

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Affiliation(s)

Xue Li Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China University of Chinese Academy of Sciences, Beijing, China
Ning Ding Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China University of Chinese Academy of Sciences, Beijing, China
Zhichao Zhang Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China University of Chinese Academy of Sciences, Beijing, China
Dehong Tian Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
Buying Han Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China University of Chinese Academy of Sciences, Beijing, China
Dehui Liu Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China University of Chinese Academy of Sciences, Beijing, China
Sijia Liu Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
Fei Tian Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
Dejun Fu Inner Mongolia Daxing 'anling Agricultural Reclamation Group Co. LTD., Hulun Buir, China
Xiaoliang Song Inner Mongolia Daxing 'anling Agricultural Reclamation Group Co. LTD., Hulun Buir, China
Kai Zhao Key Laboratory of Adaptation and Evolution of Plateau Biota, Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China

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Identification of Somatostatin Receptor Subtype 1 (SSTR1) Gene Polymorphism and Their Association with Growth Traits in Hulun Buir Sheep

This study was conducted to evaluate SSTR1 gene polymorphisms and their association with growth traits in Hulun Buir sheep. We followed 233 Hulun Buir sheep from birth to 16 months of age, born in the same pasture and on the same year under a consistent grazing conditions. The body weight (BW), body height (BH), body length (BL), chest circumference (ChC), chest depth (ChD), chest width (ChW), hip width (HW), and cannon circumference (CaC) were measured and recorded at birth, 4 months, 9 months, and 16 months of age. The polymorphisms of the SSTR1 gene in Hulun Buir sheep were excavated using exon sequencing, and association analyses of between SNPs and growth traits at each growth stage were conducted. The results showed that there were four SNPs in Exon 2 of the SSTR1 gene, SNP1, SNP2, and SNP3 were low mutation sites, and SNP4 was a moderate mutation site. Four SNPs were consistent with Hardy–Weinberg equilibrium, and all of them were synonymous mutations. The association analyses found that the genotypes of SNP2 were significantly associated with WW and BH at 4 months of age, BW, BL, ChC, and HW at 9 months of age (p < 0.05), and extremely significantly associated with ChD at 4 and 9 months of age (p < 0.01). There were significant associations between SNP3 and BH at 9 months of age, between SNP4 and ChD, ChW, and CaC at 9 months of age, and BW and ChC at 16 months of age (p < 0.05). There were no detectable associations with growth traits among the seven haplotypes between the SNP1, 3, and 4 of a strong linkage disequilibrium (p > 0.05). These results indicated that SNP2, SNP3, and SNP4 may be used as molecular markers for growth traits of Hulun Buir sheep.

Efficacy and Safety of Lanreotide Autogel in the Treatment of Clinical Symptoms Associated With Inoperable Malignant Intestinal Obstruction: A Prospective Phase II Study

PURPOSE

Inoperable malignant intestinal obstruction (IMIO) is a severe complication in patients with cancer, usually gastrointestinal or gynecologic in origin. For patients with IMIO, there is a need to relieve symptoms and limit nasogastric tube (NGT) use. Previous studies have suggested the efficacy of somatostatin analogues in relieving obstruction-related symptoms, such as nausea, vomiting, and pain. The purpose of this study was to assess the efficacy of lanreotide autogel 120 mg (LAN 120 mg) in the management of symptoms resulting from IMIO in patients with advanced cancer.

METHODS

This single-arm, multicenter study enrolled 52 patients mostly with advanced gastrointestinal or ovarian malignant tumors (35 patients with NGT and 17 patients without NGT). Patients received 1 deep subcutaneous injection of LAN 120 mg. Evaluations were performed on days 7, 14, and 28. The primary end point was the percentage of responding patients before or at day 7. Response was defined as ≤2 vomiting episodes per day (for patients without NGT at baseline) or no vomiting recurrence (after NGT removal) during at least 3 consecutive days at any time point between treatment and day 7. Responders at day 28 were offered a second LAN 120 mg injection and followed up until day 56.

FINDINGS

The proportion of responders in the intention-to-treat population was 24 of 52 (46.2%), which was significantly greater than the reference proportion of 30% (P = 0.0055). Patients without NGT had a higher response (88.2%) than patients with NGT (25.7%) and had a steady trend for clinical improvement that led to sustainable responses. Median time to response was 9 days for the overall population, 3 days for patients without NGT, and 14 days for patients with NGT (P < 0.0001).

IMPLICATIONS

Our study is the first to use long-acting LAN 120 mg in patients with IMIO and suggests an effect in controlling clinical symptoms in patients with and without NGT at baseline. The safety profile of LAN 120 mg was similar to that reported in other indications. ClinicalTrials.gov identifier: NCT02275338.

Molecular and functional characterization of somatostatin-type signalling in a deuterostome invertebrate

Somatostatin (SS) and allatostatin-C (ASTC) are structurally and evolutionarily related neuropeptides that act as inhibitory regulators of physiological processes in mammals and insects, respectively. Here, we report the first molecular and functional characterization of SS/ASTC-type signalling in a deuterostome invertebrate—the starfish Asterias rubens (phylum Echinodermata). Two SS/ASTC-type precursors were identified in A. rubens (ArSSP1 and ArSSP2) and the structures of neuropeptides derived from these proteins (ArSS1 and ArSS2) were analysed using mass spectrometry. Pharmacological characterization of three cloned A. rubens SS/ASTC-type receptors (ArSSR1–3) revealed that ArSS2, but not ArSS1, acts as a ligand for all three receptors. Analysis of ArSS2 expression in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed stained cells/fibres in the central nervous system, the digestive system (e.g. cardiac stomach) and the body wall and its appendages (e.g. tube feet). Furthermore, in vitro pharmacological tests revealed that ArSS2 causes dose-dependent relaxation of tube foot and cardiac stomach preparations, while injection of ArSS2 in vivo causes partial eversion of the cardiac stomach. Our findings provide new insights into the molecular evolution of SS/ASTC-type signalling in the animal kingdom and reveal an ancient role of SS-type neuropeptides as inhibitory regulators of muscle contractility.

Role of Somatostatin in the Regulation of Central and Peripheral Factors of Satiety and Obesity

Obesity is one of the major social and health problems globally and often associated with various other pathological conditions. In addition to unregulated eating behaviour, circulating peptide-mediated hormonal secretion and signaling pathways play a critical role in food intake induced obesity. Amongst the many peptides involved in the regulation of food-seeking behaviour, somatostatin (SST) is the one which plays a determinant role in the complex process of appetite. SST is involved in the regulation of release and secretion of other peptides, neuronal integrity, and hormonal regulation. Based on past and recent studies, SST might serve as a bridge between central and peripheral tissues with a significant impact on obesity-associated with food intake behaviour and energy expenditure. Here, we present a comprehensive review describing the role of SST in the modulation of multiple central and peripheral signaling molecules. In addition, we highlight recent progress and contribution of SST and its receptors in food-seeking behaviour, obesity (orexigenic), and satiety (anorexigenic) associated pathways and mechanism.

The Predicament of Gastrointestinal Bleeding in Patients With a Continuous-Flow Left Ventricular Assist Device: Pathophysiology, Evaluation, and Management

Heart failure affects over 5 million Americans, with numbers expected to rise. While heart transplantation is the most effective long-term strategy for end-stage heart failure, there is a limited cardiac donor pool, and these organs are often unavailable at the time of need. Left ventricular assist devices, therefore, continue to be used to bridge this gap. Originally implanted as a bridge to transplant, these devices are now additionally utilized as destination therapy for patients ineligible for transplant. With the widespread applicability of these devices for not just temporary measures, but also for prolonged use, the short- and long-term impact on other organ systems has become more evident. For example, gastrointestinal (GI) bleeding, with an incidence approaching 30%, is one such complication post-continuous-flow left ventricular assist device implantation. This high incidence of GI bleeding is thought to stem from a combination of factors, including the need for concomitant anticoagulant and antiplatelet therapy, and intrinsic device-related properties resulting in acquired Von Willebrand disease and arteriovenous malformations. Due to the significant morbidity associated with these GI bleeding events, a standardized protocol optimizing medical and endoscopic management, alongside close coordination between the gastroenterology and cardiology services, should be advocated for and ultimately employed.

Tolerability and Biological Effects of Long-Acting Octreotide in Patients With Continuous Flow Left Ventricular Assist Devices

Patients with implanted continuous, nonpulsatile, left ventricular assist devices (LVADs) have increased the occurrence of gastrointestinal bleeding (GIB). Although the pathophysiology is multifactorial, there are few treatments beyond supportive care. Octreotide acetate is a somatostatin analog that reduces GIB in various patient populations. However, there are sparse case series that suggest octreotide acetate may reduce GIB in LVAD patients. This 10 patient, 28 week phase I study evaluated the safety and tolerability of octreotide acetate long-acting release (LAR) 20 mg depot injection every 4 weeks until week 16 after LVAD placement. Secondary aims were occurrence of GIB and measurement of vascular endothelial growth factor, fibrinogen, von Willebrand factor, and platelet aggregation across the study period. Ten patients were enrolled, and eight completed the study. The two study dropouts were not related to octreotide. None of the patients experienced side effects or safety concerns related to octreotide nor did GIB occur in the study population. Vascular endothelial growth factor levels were maintained in the reference range throughout the duration of the study. There did appear to be laboratory evidence of acquired von Willebrand syndrome, with mildly low platelet aggregation studies. In conclusion, octreotide acetate LAR 20 mg depot injection was safe and effective in this population.

Bioinformatics-Based Identification of Methylated-Differentially Expressed Genes and Related Pathways in Gastric Cancer

BACKGROUND AND AIMS

The aim of the study was to identify methylated-differentially expressed genes (MDEGs) in gastric cancer and investigate their potential pathways.

METHODS

Expression profiling (GSE13911 and GSE29272) and methylation profiling (GSE25869 and GSE30601) data were obtained from GEO DataSets. Differentially expressed genes and differentially methylated genes were identified using GEO2R. Gene ontology and pathway enrichment analyses were performed for the MDEGs. Protein-protein interaction (PPI) networks were established by STRING and Cytoscape. Analysis of modules in the PPI networks was performed using MCODE. Further, the hub genes derived from the PPI networks were verified by The Cancer Genome Atlas (TCGA) database and human tissues, with methylation-specific PCR for genes methylation and real-time qPCR for genes expression.

RESULTS

A total of 445 genes were identified as hypermethylated, lowly expressed genes (Hyper-LGs), which were enriched in the regulation of system process and channel activity. A total of 129 genes were identified as hypomethylated, highly expressed genes (Hypo-HGs), which were involved in cell adhesion, cell proliferation, and protein binding. Pathway analysis showed that Hyper-LGs were associated with neuroactive ligand-receptor interaction and calcium signaling pathway, while Hypo-HGs were enriched in pathways in cancer. In the PPI networks, after verification by TCGA analysis and human tissue detection, CASR, CXCL12, and SST were identified as significantly different hub genes.

CONCLUSIONS

MDEG analysis helps to understand the epigenetic regulation mechanisms involved in the development and progression of gastric cancer. The hub genes have predictive and prognostic value as methylation-based biomarkers for the precise diagnosis and treatment of gastric cancer.

Lanreotide in the management of small bowel angioectasias: seven-year data from a tertiary centre

BACKGROUND AND AIMS

Haemorrhage from small bowel angioectasias (SBAs) can be debilitating to patients who are very often elderly and have multiple comorbidities. Our aim was to assess the use of lanreotide in addition to endotherapy in patients with SBAs.

METHOD

Patients with SBAs on capsule endoscopy (CE) who received lanreotide injections from January 2010 to till the present day at the Royal Hallamshire Hospital in Sheffield were included. Baseline demographics were recorded. Efficacy was evaluated in terms of improvement in mean haemoglobin, transfusion requirements and bleeding episodes.

RESULTS

Twelve patients (67% males, mean age 74 SD ± 15.5 years) were included. All patients had multiple comorbidities. Lanreotide was given at a dosage of 60 mg (42%), 90 mg (33%) or 120 mg (25%). It was given at a four-week interval in 75% of patients and at a six-week interval in 17% of patients. One patient (8%) received a single dose. The mean duration of treatment was 19 months SD ± 14.5. Only 17% of patients had their lanreotide stopped due to cholelithiasis. There was a significant improvement in mean haemoglobin: 86.8 versus 98.0 (131-166 g/L, p = .012). The mean number of bleeding episodes (4.18 versus 1.09, p = .010) and packed red cells (323 versus 152, p = .006) received improved. Patients required less DBEs ± APCs after starting lanreotide (19 versus 11 p = .048).

CONCLUSION

Lanreotide is a useful adjuvant treatment to therapeutic enteroscopy in patients with refractory obscure gastrointestinal bleeding due to SBAs. It improves haemoglobin levels, reduces transfusion requirements, bleeding episodes and number of DBEs. Overall, it has a good safety profile.

Gastrointestinal Angiodysplasia: Diagnosis and Management

Gastrointestinal angiodysplasia (GIAD) are red flat arborized lesions that are found throughout the entire gastrointestinal tract. GIAD can vary in size and have a range of presentation from occult to life-threatening bleeding. The typical presentation is intermittent bleeding in the setting of iron deficiency anemia. Endoscopy is the primary means of diagnosis and endoscopic therapy is noted to be initially effective. However, rebleeding can be as high as 40% to 50% in patients with small bowel GIAD. This review describes the pathophysiology for the development of GIAD and the current roles of endoscopic, medical, and surgical therapy in its treatment.

Cysteamine: a human health dietary additive with potential to improve livestock growth rate and efficiency

Cysteamine is a biological compound produced in the gastrointestinal tract and hypothalamus of all animals that acts on the somatotrophic axis. Cysteamine is finding increasing application in human medicine and also as a natural, in-feed growth promotant for monogastric and ruminant livestock that increases feed conversion efficiency, growth rate and leanness. It improves nutrient digestion and absorption by increasing portal-drained viscera blood flow and net portal absorption, while also reducing gastroenteropancreatic, plasma and hypothalamus concentrations of the inhibitory hormone, somatostatin (SRIF). Dietary inclusion rates required to achieve growth responses are typically about 10 times higher in ruminants than those required for pigs, but it is unclear whether ruminal breakdown of cysteamine is contributing to this difference. While short-term stimulation of growth, milk production and improved feed use efficiency are apparent, studies over longer periods are required, especially in breeding animals, due to the process of SRIF depletion being reversible. This review provides an overview of cysteamine’s mode of action in improving nutrient utilisation and its application in human nutrition and health, as well as its potential use as a growth promotant in the livestock industries.

Somatostatin expression in the pancreatic cells of smoking and non-smoking chronic pancreatitis patients with or without diabetes

OBJECTIVES

The aim of the analysis is to determine the location and degree of the hormone immunoreactivity in tissues of patients with chronic pancreatitis and diabetes.

METHODS

The study was performed on 11 non-smoking and 12 smoking patients with chronic pancreatitis (CP) with/without diabetes. The hormone was located in the pancreatic tissues by means of the immunohistochemical method using somatostatin antibodies. The histopathological evaluation of the hormone expression intensity in tissue sections was carried out using the semi-quantitative method and was calculated by means of a digital image analysis.

RESULTS

The hormone's strong immunohistochemical reaction and the modified D-cell location may be a result of the pancreatic tissue fibrosis process prevention in patients with CP. Changes in the intensity of SS immunoreactivity and the D-cell distribution in the pancreas of patients with CP and diabetes may possibly result from the additional hormone compensatory effect in the excessive glucagon secretion inhibition. Smoking patients with diabetes showed significantly higher hormone immunostaining in the pancreas compared to non-smoking patients without diabetes and healthy persons.

CONCLUSIONS

The severity of histopathological changes in smoking CP patients indicates that the cigarette smoke components may further exacerbate the inflammatory reactions. Patients with CP were found to have a strong immunohistochemical reaction to SS and changes in the distribution of D cells when compared to healthy patients. The strongest immunohistochemical SS reaction has been identified in the pancreatic tissue from smoking patients with diabetes.

Somatostatin analogs in the medical management of occult bleeding of the lower digestive tract

The management of occult bleeding from the lower digestive tract can be very challenging. In cases of identified angiodysplasia, the first line management options can be limited by a number of clinical or anatomical factors and an alternative approach might be required, including the use of medications. Somatostatin analogs have been considered as an effective and well-tolerated alternative management option in a number of cases where the endoscopic therapeutic approach is not practical or is unsuccessful, in patients with coagulopathies or who need concomitant anticoagulation or antiplatelet treatment. Despite the lack of double-blinded randomized placebo-control trials and despite the limitations of the available evidence in the literature, including small sample size, variable dosing, and administration routes, there is a consistent agreement in the literature that somatostatin analogs are a safe, well-tolerated, and effective therapeutic option for managing refractory or occult bleeding from the lower digestive tract, with particular reference to patients with angiodysplasia, where endoscopic or surgical management is either not feasible or unsuccessful and other pharmacological options are not preferred.

Management of gastrointestinal angiodysplastic lesions (GIADs): a systematic review and meta-analysis

OBJECTIVES

Gastrointestinal angiodysplastic lesions (GIADs) are defined as pathologically dilated communications between veins and capillaries. The objective of this systematic review and meta-analysis was to determine the efficacy of available treatment modalities for GIADs.

METHODS

We identified eligible studies by searching through PubMed, SCOPUS, and Cochrane central register of controlled trials. We searched for clinical trials examining the efficacy of endoscopic, pharmacologic, or surgical therapy for GIADs. Data were pooled using a random-effects model, and the effect of response to medical or surgical therapy was reported as odds ratios with 95% confidence intervals (CIs). Data and quality indicators were extracted by two authors from 22 studies, including 831 individuals with GIADs. The analysis included 623 patients treated with endoscopic therapy, 63 with hormonal therapy, 72 patients with octreotide, and 73 status post aortic valve replacement surgery.

RESULTS

Hormonal therapy, based on two case-control studies, was not effective for bleeding cessation (odds ratio: 1.0, 95% CI: 0.5-1.96). On the basis of 14 studies including patients with gastric, colonic, and small-bowel GIADs, endoscopic therapy was effective as initial therapy, but the pooled recurrence bleeding rate was 36% (95% CI: 28-44%) over a mean (±s.d.) of 22±13 months. The event rate for re-bleeding increased to 45% (95% CI: 37-52%) when studies including only small-bowel GIADs were included (N=341). In four studies assessing the efficacy of somatostatin analogs, the pooled odds ratio was 14.5 (95% CI: 5.9-36) for bleeding cessation. In two studies assessing the role of aortic valve replacement (AVR) in 73 patients with Heyde's syndrome, the event rate for re-bleeding was 0.19 (95% CI: 0.11-0.30) over a mean follow-up period of 4 years postoperatively.

CONCLUSIONS

Over one-third of patients with GIADs experienced re-bleeding after endoscopic therapy. Somatostatin analogs and AVR for Heyde's syndrome appeared to be effective therapy for GIADs.

Prediction of octreotide efficacy by electrogastrography in the treatment of patients with esophageal variceal hemorrhage

Our aim is to investigate the significance of electrogastrography in the treatment of esophageal variceal hemorrhage with octreotide. Electrogastrography was performed in patients with esophageal variceal hemorrhage before and during the treatment consisting of various doses of octreotide (25 ug h(-1) group and 50 ug h(-1) group). The dominant power of electrogastrography and its relationship with the hemostatic efficacy of octreotide treatment were evaluated. Dominant power of electrogastrography decreased significantly during treatment with octreotide (P < 0.05). The reduction in the amplitude of dominant power in the 50 ug h(-1) group was significantly larger than in the 25 ug h(-1) group (P < 0.05), and it was correlated with hemostatic efficacy of octreotide treatment. We conclude that octreotide treatment in patients with esophageal variceal hemorrhage can result in a significant decrease of dominant power, which correlates with the hemostatic efficacy of octreotide, so the change of dominant power could be used as a predictor of evaluating the treatment efficacy of octreotide in esophageal variceal hemorrhage patients.

Effects of octreotide on jejunal hypersensitivity triggered by Cryptosporidium parvum intestinal infection in an immunocompetent suckling rat model

BACKGROUND

Similar to other bacterial or protozoan infections, human cryptosporidiosis may trigger postinfectious irritable bowel syndrome (IBS)-like symptoms, a condition in which enhanced visceral perception of pain during intestinal distension plays a pivotal role. In an immunocompetent suckling rat model which mimicks features of postinfectious IBS, Cryptosporidium parvum infection induces long-lasting jejunal hypersensitivity to distension in association with intestinal activated mast cell accumulation. The aim of the present study was to explore in this model whether octreotide, a somatostatin agonist analog, could prevent the development of jejunal hypersensitivity and intestinal mast cell/nerve fiber accumulation.

METHODS

Five-day-old Sprague-Dawley rats were infected with C. parvum and treated 10 days later with octreotide (50 g kg(-1) day(-1), i.p.) for 7 days.

KEY RESULTS

Compared with untreated infected rats, octreotide treatment of infected rats resulted in increased weight gain [day 23 postinfection (PI)], decreased food intake (day 16 PI), and a reduction in jejunal villus alterations (day 14 PI), CD3(+) IEL (day 37 PI) and mast cell (days 37 and 50 PI) accumulations, nerve fiber densities (day 50 PI), and hypersensitivity to distension (day 120 PI). In uninfected rats, the effects of octreotide treatment were limited to higher weight gain (days 16 and 23 PI) and decreased food intake (day 23 PI) compared with uninfected-untreated rats.

CONCLUSIONS & INFERENCES

Data confirms the relevance of the present rat model to postinfectious IBS studies and prompt further investigation of somatostatin-dependent regulatory interactions in cryptosporidiosis.

Systematic review and meta-analysis of the role of somatostatin and its analogues in the treatment of enterocutaneous fistula

OBJECTIVE

Somatostatin analogues may help pancreatic fistula although it remains unclear whether they help nonpancreatic fistula. This study involved meta-analysis of somatostatin analogues for treatment of enterocutaneous fistula.

METHODS

Meta-analysis of studies was undertaken, to estimate the effect of somatostatin analogues on spontaneous closure, time to closure and mortality.

RESULTS

Results showed significant associations between somatostatin and both spontaneous closure rate [odds ratio (OR) 6.61, 95% (CI) confidence interval 1.35-32.43] and time to closure (standardized mean difference -0.80, 95% CI: -1.34 to -0.26). Octreotide reduced closure time (standardized mean difference -0.57, 95% CI: -0.95 to -0.20) but not spontaneous closure (OR: 1.74, 95% CI: 0.64-4.76). Lanreotide also improved time to closure (mean of 17 days vs. 26 days, standard deviation not stated) but not spontaneous closure (OR: 0.94, 95% CI: 0.42-2.12). Somatostatin, octreotide and lanreotide did not significantly affect mortality (OR: 0.30, 0.82, and 0.48; 95% CI: 0.03-3.47, 0.38-1.78, and 0.04-5.07 respectively).

CONCLUSION

Somatostatin and octreotide improved fistula closure time but only somatostatin improved spontaneous closure rate.

Gene expression profiles of colonic mucosa in healthy young adult and senior dogs

Background

We have previously reported the effects of age and diet on nutrient digestibility, intestinal morphology, and large intestinal fermentation patterns in healthy young adult and senior dogs. However, a genome-wide molecular analysis of colonic mucosa as a function of age and diet has not yet been performed in dogs.

Methodology/Principal Findings

Colonic mucosa samples were collected from six senior (12-year old) and six young adult (1-year old) female beagles fed one of two diets (animal protein-based vs. plant protein-based) for 12 months. Total RNA in colonic mucosa was extracted and hybridized to Affymetrix GeneChip® Canine Genome Arrays. Results indicated that the majority of gene expression changes were due to age (212 genes) rather than diet (66 genes). In particular, the colonic mucosa of senior dogs had increased expression of genes associated with cell proliferation, inflammation, stress response, and cellular metabolism, whereas the expression of genes associated with apoptosis and defensive mechanisms were decreased in senior vs. young adult dogs. No consistent diet-induced alterations in gene expression existed in both age groups, with the effects of diet being more pronounced in senior dogs than in young adult dogs.

Conclusion

Our results provide molecular insight pertaining to the aged canine colon and its predisposition to dysfunction and disease. Therefore, our data may aid in future research pertaining to age-associated gastrointestinal physiological changes and highlight potential targets for dietary intervention to limit their progression.

Recurrent obscure gastrointestinal bleeding: dilemmas and success with pharmacological therapies. Case series and review

The present article describes three difficult cases of recurrent bleeding from obscure causes, followed by a review of the pitfalls and pharmacological management of obscure gastrointestinal bleeding. All three patients underwent multiple investigations. An intervening complicating diagnosis or antiplatelet drugs may have compounded longterm bleeding in two of the cases. A bleeding angiodysplasia was confirmed in one case but was aggravated by the need for anticoagulation. After multiple transfusions and several attempts at endoscopic management in some cases, long-acting octreotide was associated with decreased transfusion requirements and increased hemoglobin levels in all three cases, although other factors may have contributed in some. In the third case, however, the addition of low-dose thalidomide stopped bleeding for a period of at least 23 months.

Evolution of the restorative proctocolectomy and its effects on gastrointestinal hormones

Gastrointestinal (GI) peptide hormones are chemical messengers that regulate secretory, mechanical, metabolic, and trophic functions of the gut. Restorative proctocolectomy (RPC) or resection of the colon and rectum with maintenance of intestinal continuity through the construction of an ileal pouch reservoir and preservation of the anal sphincters has become the standard of care for the surgical treatment of ulcerative colitis and familial adenomatous polyposis. The manipulation of the digestive system to create the ileal pouch involves altering gut-associated lymphoid tissue among other anatomic changes that lead to changes in GI peptides. In addition, the ileal pouch epithelium responds to a wide variety of stimuli by adjusting its cellularity and function. These adaptive mechanisms involve systemic factors, such as humoral and neural stimuli, as well as local factors, such as changes in intestinal peristalsis and intraluminal nutrients. There have been conflicting reports as to whether the alterations in GI hormones after RPC have actual clinical implications. What the studies on alterations of GI peptides' response and behavior after RPC have contributed, however, is a window into the possible etiology of complications after pouch surgery, such as pouchitis and malabsorption. Given the possibility of pharmacologically modifying GI peptides or select components of adaptation as a therapeutic strategy for patients with ileal pouch dysfunction or pouchitis, a clear understanding of human pouch mucosal adaptation is of paramount importance. In this review, we summarize the evolution of the RPC and its effects on the GI hormones as well as their possible clinical implications.

Effect of long-term treatment with octreotide on rectal sensitivity in patients with non-constipated irritable bowel syndrome

BACKGROUND

Acute administration of octreotide reduces visceral perception and therefore has been suggested as potential treatment for irritable bowel syndrome. Whether prolonged treatment with octreotide also reduces visceral sensitivity and improves gastrointestinal symptoms remains, however, unknown.

AIM

To investigate the effect of a slow release preparation of octreotide on rectal sensitivity and symptoms in irritable bowel syndrome patients.

METHODS

Forty-six non-constipated irritable bowel syndrome patients (52% female, 19-63 years) participated. Before and after 8 weeks of treatment with octreotide (Sandostatin LAR 20 mg i.m.) or placebo, patients underwent a barostat study to assess the rectal sensitivity. During a 2-week run-in period and treatment, abdominal pain, defecation frequency, consistency and symptom relief were scored weekly.

RESULTS

Octreotide, but not placebo, significantly increased the threshold for first sensation. Thresholds for urge to defecate and discomfort/pain and rectal compliance were not altered by either treatment. Octreotide improved stool consistency compared with placebo (loose stools after eight weeks: octreotide: 52%, placebo: 81%, P < 0.05). In contrast, abdominal pain and defecation frequency were not affected.

CONCLUSIONS

Although the threshold of first rectal sensation increased and stool consistency improved, long-term treatment with octreotide, at least at the current dose used, has no visceral analgesic effect and fails to improve irritable bowel syndrome symptoms.

Spontaneous hypersensitivity in mesenteric afferent nerves of mice deficient in the sst2 subtype of somatostatin receptor

Somatostatin is an inhibitory peptide present in abundance in the gastrointestinal (GI) tract. The effects of somatostatin are mediated through its interaction with a family of G-protein-coupled receptors, namely sst1-5. Previous evidence suggested that the sst2 receptor mediates an inhibitory role of somatostatin on GI afferent nerve sensitivity. In the present study we further evaluated mechanical and chemical sensitivity of mesenteric afferents in mice deficient in the sst2 receptor. Multi-unit recordings were made from mesenteric afferents from mouse jejunal segments perfused in vitro. Ramp distension of the jejunum up to 60 mmHg induced biphasic increases in afferent activity in both wild-type (WT) and sst2 gene knock-out (KO) mice. However, the level of afferent activity was significantly higher in the KO (n=15) compared to the WT (n=16) mice across the entire pressure range. The mesenteric afferent sensitivity to acid was evaluated by intraluminal infusion of hydrochloric acid (HCl 20 mM) for 2 min. Peak afferent discharge rate following acid infusion was significantly greater in KO (36.76 +/- 6.47 impulses s(-1), n=7) than in WT preparations (16.53 +/- 3.91 impulses s(-1), n=5, P<0.01). The response to bath-applied bradykinin (1 microm, 3 ml) was not significantly different in the KO and the WT preparations. It is interesting that in the WT preparations, octreotide inhibited both low- and high-threshold mechanosensory responses, whereas in the sst2 KO group it appeared to inhibit the low-threshold responses preferentially and failed to affect the high-threshold responses. The results of the present investigation demonstrate that sst2 deficiency is associated with exaggerated jejunal afferent sensitivity to both mechanical and chemical stimulations, suggesting that somatostatin plays an important inhibitory role in the control of visceral sensitivity by interacting with the sst2 receptor.

Pharmacological therapy of vascular malformations of the gastrointestinal tract

Vascular malformation (AVM) in the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and iron deficiency anemia, especially in an aging population. While endoscopic coagulative therapy is the method of choice for controlling bleeding, a substantial number of cases require additional therapy. Adjunctive or even primary phamacotherapy may be indicated in recurrent bleeding. However, there is little evidence-based proof of efficacy for any agent. The bulk of support is derived from anecdotal reports or case series. The present review compares the outcome of AVM after no intervention, coagulative therapy or focus on pharmacological agents. Most of the literature encompasses two common AVMs, angiodysplasia and hereditary hemorrhagic telangiectasia. Similarly, the bulk of information evaluates two therapies, hormones (estrogen and progesterone) and the somatostatin analogue octreotide. Of these, the former is the only therapy evaluated in randomized trials, and the results are conflicting without clear guidelines. The latter therapy has been reported only as case reports and case series without prospective trials. In addition, other anecdotally used medications are discussed.

Consequences of Citrobacter rodentium infection on enteroendocrine cells and the enteric nervous system in the mouse colon

We tested the hypothesis that Citrobacter rodentium infection leads to changes in the mucosal enteroendocrine signalling and the enteric nervous system and that the host's immune response contributes to these changes. Enteroendocrine cells, serotonin (5-HT) reuptake transporter (SERT), 5-HT release, and inducible nitric oxide synthase (iNOS) expression were assessed in the colon of infected wild-type or severe combined immunodeficient (SCID) mice. Immunoreactivity for iNOS and neuropeptides were examined in the submucosal and myenteric plexuses. Mice were orogastrically infected with C. rodentium and experiments were conducted during the injury phase (10 days) and the recovery phase (30 days). 5-HT and somatostatin enteroendocrine cells and SERT were significantly reduced 10 days after infection, with numbers returning to control values at 30 days. 5-HT release was increased at 10 days. Changes to the mucosal serotonin signalling system were not observed in SCID mice. iNOS immunoreactivity was increased in the submucosa and mucosa at 10 days and returned to baseline levels by 30 days. No differences were observed in neuropeptide or iNOS immunoreactivity in the enteric plexuses following infection. The host's immune response underlies changes to enteroendocrine cells, SERT expression and 5-HT release in C. rodentium infection. These changes could contribute to disturbances in gut function arising from enteric infection.

Somatostatin receptor subtypes mediate contractility on human colonic smooth muscle cells

This study demonstrates the expression of functional somatostatin receptor (sstr) subtypes in human circular and longitudinal colonic smooth muscle cells (SMC). Native somatostatin (SS) and sstr subtype-specific analogues were used to characterize the sstr subtypes present in both cell types by contraction/relaxation studies. Qualitative and quantitative mRNA analysis and immunohistochemistry of sstr subtypes were also carried out. sstr subtype 2 mRNA was expressed in circular SMC, and various levels of subtypes 1, 2 and 3 mRNA were expressed in longitudinal colonic SMC. Native SS and each subtype-specific analogue exerted a modest, but significant, contraction, although inhibition of carbachol-induced contraction (relaxation) was the main effect on SMC from both layers. CH-288, a sstr subtype 1-specific analogue, and octreotide, a sstr subtype 2-specific analogue, were the most effective relaxant analogues on longitudinal and circular SMC, respectively. sstr subtypes display a distinct expression pattern on human colonic SMC; on circular SMC, subtype 2 is the only sstr, whereas sstr subtypes 1, 2 and 3 are expressed on human SMC isolated from the longitudinal layer. The contractile effects of SS are mediated through sstr subtype 2 and sstr subtype 1 on circular and longitudinal human colonic SMC, respectively.

Effects of duodenogastric reflux on gastrin cells, somatostatin cells and serotonin cells in human antral gastric mucosa

Duodenogastric reflux (DGR) has been found to give rise to a hypochlorhydria secondary to alkaline reflux. We investigated whether there is a link between DGR and the gastrin, somatostatin, and serotonin cell numbers and the granular content of gastrin, somatostatin, and serotonin in endocrine cells in human antral mucosa. We investigated 38 selected Helicobacter pylori-negative patients with visual primary excessive DGR in upper endoscopy and symptoms of epigastric pain and bile vomiting. Ten control patients were included in this study. None of the patients had peptic ulcer or had received any medication. Antrum (10 biopsies from five different zones: the lesser and major curvature, the anterior and posterior wall, and the pylorus) and corpus (two biopsies from major curvature about 10 cm below the cardia) biopsy specimens were collected for routine histology, as well as for light and electron immunohistochemistry. In patients without atrophy or intestinal metaplasia and in patients with mild atrophy or mild intestinal metaplasia, the number of gastrin and somatostatin cells was not different from that in controls. In moderate atrophy or moderate intestinal metaplasia, however, the number of gastrin and somatostatin cells decreased. Serotonin cell number was significantly higher in all patients with DGR as compared with controls. The mean somatostatin granular content was increased (3.6+/-0.2 vs. 3.2+/-0.1). In addition, lysosomes with engulfed somatostatin granules were found. The mean serotonin granular content was decreased (2.3+/-0.3 vs. 2.9+/-0.3), while the mean gastrin granular content remained unchanged (2.5+/-0.3 vs. 2.4+/-0.2). Ultrastructurally, the granules in serotonin-positive cells corresponded to the gastric variant or to the intestinal variant of serotonin cells. The endocrine cells were found to have few granules positive for serotonin. It is concluded that DGR inhibits somatostatin granular release, but stimulates both serotonin granular release and serotonin cell growth.

Enteroendocrine cells and 5-HT availability are altered in mucosa of guinea pigs with TNBS ileitis

Enteroendocrine cells act as sensory transducers, releasing 5-HT and numerous peptides that are involved in regulating motility, secretion, and gut sensation. The action of mucosal 5-HT is terminated by a 5-HT reuptake transporter (SERT). In this study, we examined the hypothesis that ileitis leads to changes in enteroendocrine cell populations and mucosal 5-HT availability. Ileitis was induced in guinea pigs by intraluminal injection of 2,4,6-trinitrobenzenesulfonic acid and experiments were conducted 3, 7, and 14 days after treatment. The number of somatostatin, neurotensin, and 5-HT-immunoreactive cells increased at 3 and 7 days of ileitis, respectively, whereas no significant changes in the numbers of cholecystokinin, glucagon-like peptide-2, glucose-dependent insulinotropic peptide, and peptide YY-immunoreactive cells were observed. Chemical stimulation of the inflamed mucosa with sodium deoxycholic acid significantly increased 5-HT release compared with basal release. Mechanical stimulation of the mucosa potentiated the effect of the chemical stimuli at day 7. Epithelial SERT immunoreactivity was significantly reduced during the time course of inflammation. Thus changes in enteroendocrine cell populations and 5-HT availability could contribute to the altered motility and secretion associated with intestinal inflammation by disrupting mucosal signaling to enteric nerves involved in peristaltic and secretory reflexes.

Ultrastructural immunohistochemical localization of gastrin, somatostatin and serotonin in endocrine cells of human antral gastric mucosa

Five types of endocrine cells are found in the human antral gastric mucosa: gastrin (G) cells, somatostatin (D) cells, enterochromaffin (EC) cells and cells with an unknown secretory product (D1 cells and P cells). The content of secretory granules, gastrin, somatostatin and serotonin, was evaluated using electron microscopic immunohistochemistry and was compared with the granular content in G cells, D cells and EC cells as determined by routine electron microscopy. Semi-quantitative scoring of the granular content was performed on a scale 1-4 (empty-full). The content of gastrin (2.5 +/- 0.2) and somatostatin (3.3 +/- 0.2) in the granules was not different from the granular content in G cells (2.5 +/- 0.3; p > 0.05) and D cells (3.5 +/- 0.2; p > 0.05). Gastrin was also found in G cells in a nongranular form. The content of serotonin in granules (2.8 +/- 0.3) was smaller than the granular content in EC cells (3.7 +/- 0.2; p < 0.05). In intermediate-full and intermediate-empty granules, serotonin was localized in the periphery of granules whereas the granular content in EC cells was localized in an eccentric or central pattern. The granular content of D1 cells and P cells was 3.8 +/- 0.2, and 3.4 +/- 0.2, respectively. It is concluded that gastrin and somatostatin immunostaining in granules of G cells and D cells reflects the granular content in G cells and D cells, respectively, whereas serotonin immunostaining does not agree with the granular content of EC cells.

Role of gastrointestinal hormones in the proliferation of normal and neoplastic tissues

Gastrointestinal (GI) hormones are chemical messengers that regulate the physiological functions of the intestine and pancreas, including secretion, motility, absorption, and digestion. In addition to these well-defined physiological effects, GI hormones can stimulate proliferation of the nonneoplastic intestinal mucosa and pancreas. Furthermore, in an analogous fashion to breast and prostate cancer, certain GI cancers possess receptors for GI hormones; growth can be altered by administration of these hormones or by blocking their respective receptors. The GI hormones that affect proliferation, either stimulatory or inhibitory, include gastrin, cholecystokinin, gastrin-releasing peptide, neurotensin, peptide YY, glucagon-like peptide-2, and somatostatin. The effects of these peptides on normal and neoplastic GI tissues will be described. Also, future perspectives and potential therapeutic implications will be discussed.

Modern management of cancer-related intestinal obstruction

Malignant-associated bowel obstruction remains a common and perplexing problem for patients with advanced gynecologic and gastrointestinal malignancies. The ability to locate and define its cause preoperatively has improved with the advent of computed tomography. Initial clinical experience with half-Fourier acquisition single-shot turbo spin-echo magnetic resonance imaging (HASTE MRI) and virtual colonoscopy is exciting. The surgical approach for primary obstructing colon cancer has become more aggressive, with experienced surgical groups doing one-stage procedures. Yet to be defined are guidelines for surgical management of obstructions occurring in the face of recurrent disease. Stent placement for upper and lower bowel obstructions is an option in nonoperable patients. Pharmacologic symptom management for intestinal obstructions consists of an opioid, an anticholinergic, and an antiemetic. Octreotide, either alone or added to the original regimen, will palliate symptoms that are resistant to the three-drug combination.

Electron microscopic immunohistochemical investigation of chromogranin A in endocrine cells in human oxyntic gastric mucosa

Human oxyntic gastric mucosa harbours 6 types of endocrine cells: enterochromaffin-like (ECL) cells, enterochromaffin (EC) cells, somatostatin (D) cells, and cells with an unknown secretory product (P cells, D1 cells and X (A-like) cells). In the present study, intracellular localization and granular content of chromogranin A (CGA) in these cells have been investigated by electron microscopic immunohistochemistry. The content of CGA in granules of the various types of endocrine cells was evaluated and compared with the content of serotonin and somatostatin in EC cells and D cells, respectively. ECL cells, EC cells, P cells, D1 cells and X cells contained CGA in their granules, whereas D cells did not. CGA granular content in ECL cells, P cells, D1 cells and X cells was 3.39 +/- 0.17, 3.41 +/- 0.21, 3.58 +/- 0.18, and 3.55 +/- 0.09, respectively. In ECL cells, CGA was also found in a nongranular form. The CGA content in EC cells (2.95 +/- 0.21) was not significantly different from the serotonin content (2.82 +/- 0.11; p > 0.05) which is in line with the basic significance of CGA as potential amine storage and release protein. The somatostatin content in D cells was 3.30 +/- 0.15. Our study has established high content of CGA in granules of all types of endocrine cells in human oxyntic gastric mucosa except in D cells.

Light and electron microscopic immunohistochemical investigation on G and D cells in antral mucosa in Helicobacter pylori-related gastritis

Recently, it has been recognized that Helicobacter pylori (H. pylori) infection is associated with an exaggeration of basal and meal gastrin secretion. We investigate whether there is a relationship between H. pylori-related chronic gastritis and G-cell and D-cell number and granule density index of G and D cells. - The number of antral G cells and D cells and granule density index of D and G cells are compared between thirty two patients with H. pylori-related chronic gastritis and twelve patients without H. pylori and inflammation. Antral mucosal biopsy specimens are examined using light and electron immunohistochemical techniques. - The number of G cells is the same in either infected or uninfected patients (98.40 +/- 11.39, 109.25 +/- 12.76 vs 101.17 +/- 7.72 for infected patients with non atrophic and with mild atrophic chronic gastritis and uninfected controls, respectively) except for the cases with moderate gastric mucosal atrophy, where G cells (58.22 +/- 5.63) decrease in number. The number of D cells is decreased in all patients with H. pylori-related gastritis. G cell granule density index is significantly (p < 0.05) increased in patients with H. pylori-related chronic gastritis than in controls (3.15 +/- 0.43 vs 2.528 +/- 0.01). D cell granule density index is similar between patients with H. pylori chronic gastritis and controls (3.18 +/- 0.05 vs 3.166 +/- 0.12). It is concluded that decreased D cells number in patients with H. pylori-related chronic gastritis might be one of the reasons for the existing hypergastrinaemia.

Modern management of cancer-related intestinal obstruction

Malignant associated bowel obstruction remains a common and perplexing problem for patients with advanced gynecologic and gastrointestinal malignancies. The ability to locate and define its cause preoperatively has improved with the advent of computed tomography. Initial clinical experience with half-Fourier acquisition single-shot turbo spin-echo magnetic resonance imaging (HASTE MRI) and virtual colonoscopy is exciting. The surgical approach for primary obstructing colon cancer has become more aggressive, with experienced surgical groups doing one-stage procedures. Yet to be defined are guidelines for surgical management of obstructions occurring in the face of recurrent disease. Stent placement for upper and lower bowel obstructions is an option in nonoperable patients. Pharmacologic symptom management for intestinal obstructions consists of an opioid, an anticholinergic, and an anti-emetic. Octreotide, either alone or added to the original regimen, will palliate symptoms that are resistant to the three-drug combination.