Stage Ⅳ non-small cell lung cancer with multiple metastases to the small intestine leading to intussusception: A case report

BACKGROUND Gastrointestinal tract metastasis from lung cancer is rare and compared to small cell lung cancer(SCLC),non-SCLC(NSCLC)is even less likely to metastasize in this manner.Additionally,small intestinal tumors can also present with diverse complications,some of which require urgent intervention.CASE SUMMARY In this report,we detail a unique case of stage IV lung cancer,where the presence of small intestine tumors led to intussusception.Subsequent to a small intestine resection,pathology confirmed that all three tumors within the small intestine were metastases from adenocarcinoma of the lung.The postoperative follow-up period extended beyond 14 mo.CONCLUSION In patients with stage IV NSCLC,local tumor control can be achieved with various treatments.However,if small intestinal metastasis occurs,surgical intervention remains necessary,as it may improve survival.

Simultaneously metastatic cholangiocarcinoma and small intestine cancer from breast cancer misdiagnosed as primary cholangiocarcinoma:A case report

BACKGROUND Cholangiocarcinoma and small intestine cancer are common clinical malignancies,but metastatic cholangiocarcinoma and small intestine cancer are rare,especially simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer.Since the clinical presentation of metastatic cholangiocarcinoma and small intestine cancer does not differ from primary tumor,it may lead to misdiagnosis preoperatively.CASE SUMMARY A 66-year-old woman was admitted to our hospital for further treatment due to abdominal pain and jaundice.Abdominal magnetic resonance imaging and magnetic resonance cholangiopancreatography showed an occupying lesion of the bile duct,considering a high possibility of primary bile duct tumor.Therefore,we performed a radical bile duct cancer surgery and cholecystectomy,and multiple tumors in the small intestine were found and removed during the surgery process.Postoperative pathology showed metastatic bile duct cancer and small intestine cancer from tumors in other parts.The patient underwent a right total mastectomy and axillary lymph node dissection because of right breast cancer 2 years ago.Combining with the immunohistochemical results,the patient was finally diagnosed as metastatic cholangiocarcinoma and metastatic small intestine cancer from breast cancer.Postoperatively,the patient received four cycles of chemotherapy and targeted therapy with docetaxel,capecitabine and trastuzumab.Unfortunately,the patient eventually died from tumor progression,thoracoabdominal infection,and sepsis 5 mo after surgery.CONCLUSION Simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer are rare and the prognosis is extremely poor.Improving preoperative diagnostic accuracy is beneficial to avoid excessive surgical treatment.Treatment should be aimed at relieving biliary obstruction and abdominal pain,and then supplemented with chemotherapy and targeted therapy to control tumor progression and prolong the patient’s life.

Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days.From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 days: TPNcon group, receiving TPN and enteral 20 g x L(-1) glycine perfusion; TPN+Gln group, receiving TPN and enteral 20 g x L(-1) glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g x L(-1) glycine; EN+Gln group, enteral nutrition fortified with 20 g x L(-1) glutamine; EN+Fib group, enteral nutrition and 2 g x d(-1) oral soybean fiber; EN+GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3 IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection. RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 microm +/- 29 microm in TPNcon vs 330 microm +/- 54 microm in TPN+Gln, ileal villus height 260 microm +/- 28 microm in TPNcon vs 330 microm +/- 22 microm in TPN+Gln, P【0.05) and mucosa thickness (jejunal mucosa thickness 360 microm +/- 32 microm in TPNcon vs 460 microm +/- 65 microm in TPN+Gln, ileal mucosa thickness 400 microm +/- 25 microm in TPNcon vs 490 microm +/- 11 microm in TPN+Gln,P【 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g +/- 3.6g in EN+Fib, 265.7 g +/- 3.3 g in EN+GH, vs 257 g +/- 3.3 g in ENcon, P【 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 microg x L(-1). 52 microg x L-(-1) in EN+Fib,1200 microg x L(-1). 96 microg x L-(-1) in EN +/- GH, vs 620 microg x L(-1).43 microg x L-(-1) in ENcon, P【 0.05), and increased the villus height (jejunum 560 microm +/- 44 microm in EN +/- Fib, 530 microm +/- 30 microm in EN +/- GH, vs 450 microm +/- 44 microm in ENcon, ileum 400 microm +/- 30 microm in EN+Fib, P【0.05) and the mucosa thickness (jejunum 740 microm +/- 66 microm in EN +/- Fib, 705 microm +/- 27 microm in EN +/- GH, vs 608 microm +/- 58 microm in ENcon, ileum 570 microm +/- 27 microm in EN +/- Fib, 560 microm +/- 56 microm in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g +/- 2.2g), plasma IGF-I level (1450 microg x L(-1). 137 microg x L-(-1)), and villus height (jejunum 620 microm +/- 56 microm, ileum 450 microm +/- 31 microm) and mucosal thickness (jejunum 800 microm +/- 52 microm, ileum 633 microm +/- 33 microm) than those in ENcon, EN+Gln (jejunum villus height and mucosa thickness 450 microm +/- 47 microm and 610 +/- 63 microm, ileum villus height and mucosa thickness 330 microm +/- 39 microm and 500 microm +/- 52 microm), EN+GH groups (P【0.05), and than those in EN+Fib group although no statistical significance was attained. CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN.

Neuroendocrine Tumor of Small Intestine, a Diagnostic Challenge

Incidence of neuroendocrine tumors (NET) has significantly increased in the past three decades. In the small intestine, NET are the most frequent tumors, even more frequent than adenocarcinomas. Due to atypical presentations and late symptoms, NET in the small intestine frequently represent a diagnostic challenge. It is important to take these tumors into consideration in differential diagnosis of gastrointestinal neoplasms. Surgeons, oncologists, endocrinologists, and gastroenterologists should understand the disease characteristics and management alternatives. This document aims to review the key points of NET and main diagnostic tools. We present the case of a 50-year-old male who presented lower gastrointestinal bleeding. Imaging and endoscopic studies showed no conclusive findings. A capsule endoscopy showed multiple ulcered lesions with neoplastic aspect in the distal jejune. Due to the multifocal nature of the lesions, clinicians suspected NET-associated digestive bleeding. The patient underwent exploratory laparoscopy with ileectomy and radical abdominal lymphadenectomy. Histopathologic examination confirmed the suspected diagnosis of NET. This case reflects the complexity of diagnostic approach and differential diagnoses for these tumors.

Morphological properties and residual strain along the small intestine in rats

AIM: Residual stress and strain are important for gastrointestinal function and relate to the geometric configuration, the loading conditions and the zero-stress state of the gastrointestinal tract. The purpose of this project is to provide morphometric data and residual strains for the rat small intestine ( n =11). METHODS: To approach the no-load state, the intestine was surgically excised, transferred to an organ bath and cut transversely into short ring-shaped segments. Each ring was cut radially for obtaining the zero-stress state. The residual stress can be characterised by an opening angle. The strain difference between the zero-stress state and the no-load state is called residual strain. RESULTS: Large morphometric variations were found along the small intestine. The wall thickness was highest in the proximal duodenum and decreased in distal direction along the axis of the small intestine (P【0.001). The circumferential length of the inner and outer surfaces decreased rapidly along the length of duodenum by 30-50% (P【0.001). The wall area and lumen area showed a similar pattern (P【0.001). In zero-stress state the rings always opened up after making the cut. The experiments resulted in larger inner circumferential length and smaller outer circumferential length when compared to the no-load state. The wall thickness and wall area did not differ between the no-load and zero-stress state. The opening angle and tangent rotation angle increased along the length of the duodenum and had its highest value 30% down the intestine. Further down the intestine it decreased again (P【0.001). The serosal residual strain was tensile with the highest value close to the ligament of Treitz (P【0.001). The mucosal residual strain was compressive in all segments of the small intestine with average values between -0.25 and -0.4 and with the lowest values close to the ligament of Treitz (P【0.001). CONCLUSION: Axial variation in morphometric properties and residual strains were found in the small intestine. Existence of large residual strains indicates that the zero-stress state must be considered in future biomechanical studies in the gastrointestinal tract.

Surgical treatments of recurrent small intestine metastatic melanoma manifesting with gastrointestinal hemorrhage and intussusception:A case report

BACKGROUND Melanoma is the most aggressive form of skin cancer,with a tendency to metastasize to any organ.Malignant melanoma is the most frequent cause of skin cancer-related deaths worldwide.Small intestine cancers especially small intestine metastases are relatively rare.Small intestine metastases are seldom described and likely underdiagnosed.Intussusception is most common in pediatric age,and in adults are almost 5%of all cases.CASE SUMMARY A 75-year-old man with a history of acral malignant melanoma was admitted to the Gastroenterology Department of our hospital,complaining of intermittent melena for 1 mo.Magnetic resonance enterography showed partial thickening of the jejunal wall and formation of a soft tissue mass,indicating a neoplastic lesion with jejunojejunal intussusception.The patient underwent partial small bowel resection.Pathological findings and immunohistochemical staining indicated small intestine metastatic melanoma.The patient refused further anti-tumor treatment after the surgery.Ten months after the first surgery,the patient presented with melena again.Computed tomography enterography showed the anastomotic stoma was normal without thickening of the intestinal wall,and routine conservative treatment was given.Three months later,the patient developed melena again.The patient underwent a second surgery,and multiple metastatic melanoma lesions were found.The patient refused adjuvant anti-tumor treatment and was alive at the latest follow-up.CONCLUSION Small intestine metastatic melanoma should be suspected in any patient with a history of malignant melanoma and gastrointestinal symptoms.

Heterogeneity across the murine small and large intestine

The small and large intestine of the gastrointestinal tract(GIT) have evolved to have discrete functions with distinct anatomies and immune cell composition.The importance of these differences is underlined when considering that different pathogens have uniquely adapted to live in each region of the gut.Furthermore,different regions of the GIT are also associated with differences in susceptibility to diseases such as cancer and chronic inflammation.The large and small intestine,given their anatomical and functional differences,should be seen as two separate immunological sites.However,this distinction is often ignored with findings from one area of the GIT being inappropriately extrapolated to the other.Focussing largely on the murine small and large intestine,this review addresses the literature relating to the immunology and biology of the two sites,drawing comparisons between them and clarifying similarities and differences.We also highlight the gaps in our understanding and where further research is needed.

AN ANALYTICAL SOLUTION FOR THE MODEL OF DRUG DISTRIBUTION AND ABSORPTION IN SMALL INTESTINE

According to the physiological and anatomical characteristics of small intestine,neglecting the effect of its motility on the distribution and absorption of drug and nutrient,Y.Miyamoto et al.proposed a model of two-dimensional laminar flow in a circular porous tube with permeable wall and calculated the concentration profile of drugby numerical analysis.In this paper,we give a steady-state analytical solution of the above model including deactivationterm.The obtained results are in agreement with the results of their numerical analysis. Moreover the analytical solution presented in this paper reveals the relation among the physiological parameters of the model and describes the basic absorption rule of drug and nutrient through the intestinal wall and hence pro- vides a theoretical basis for determining the permeability and reflection coefficient through in situ experiments.

Risk factors for small intestinal adenocarcinomas that are common in the proximal small intestine

The frequency of primary small intestinal adenocarcinoma is increasing but is still low.Its frequency is approximately 3%of that of colorectal adenocarcinoma.Considering that the small intestine occupies 90%of the surface area of the gastrointestinal tract,small intestinal adenocarcinoma is very rare.The main site of small intestinal adenocarcinoma is the proximal small intestine.Based on this characteristic,dietary animal proteins/lipids and bile concentrations are implicated and reported to be involved in carcinogenesis.Since most nutrients are absorbed in the proximal small intestine,the effect of absorbable intestinal content is a suitable explanation for why small intestinal adenocarcinoma is more common in the proximal small intestine.The proportion of aerobic bacteria is high in the proximal small intestine,but the absolute number of bacteria is low.In addition,the length and density of villi are greater in the proximal small intestine.However,the involvement of villi is considered to be low because the number of small intestinal adenocarcinomas is much smaller than that of colorectal adenocarcinomas.On the other hand,the reason for the low incidence of small intestinal adenocarcinoma in the distal small intestine may be that immune organs reside there.Genetic and disease factors increase the likelihood of small intestinal adenocarcinoma.In carcinogenesis experiments in which the positions of the small and large intestines were exchanged,tumors still occurred in the large intestinal mucosa more often.In other words,the influence of the intestinal contents is small,and there is a large difference in epithelial properties between the small intestine and the large intestine.In conclusion,small intestinal adenocarcinoma is rare compared to large intestinal adenocarcinoma due to the nature of the epithelium.It is reasonable to assume that diet is a trigger for small intestinal adenocarcinoma.

PRIMARY TUMORS OF THE SMALL INTESTINE (ANALYSIS OF 102 PATIENTS)

Primary tumors of the small intestine are uncommon and a correct preoperative diagnosis is extremely difficult. From 1964 to 1983, 102 cases of this disease were detected surgically at our hospital. In order to investigate the problems involved in diagnosis and treatment, a comprehensive analysis of small intestinal tumors is made in this paper.

What are the effects of proton pump inhibitors on the small intestine?

Generally, proton-pump inhibitors(PPIs) have great benefit for patients with acid related disease with less frequently occurring side effects. According to a recent report, PPIs provoke dysbiosis of the small intestinal bacterial flora, exacerbating nonsteroidal anti-inflammatory drug-induced small intestinal injury.Several meta-analyses and systematic reviews have reported that patients treated with PPIs, as well as post-gastrectomy patients, have a higher frequency of small intestinal bacterial overgrowth(SIBO) compared to patients who lack the aforementioned conditions.Furthermore, there is insufficient evidence that these conditions induce Clostridium difficile infection. At this time, PPI-induced dysbiosis is considered a type of SIBO. It now seems likely that intestinal bacterial flora influence many diseases, such as inflammatory bowel disease, diabetes mellitus, obesity, nonalcoholic fatty liver disease, and autoimmune diseases.When attempting to control intestinal bacterial flora with probiotics, prebiotics, and fecal microbiota transplantation, etc., the influence of acid suppression therapy, especially PPIs, should not be overlooked.

Morphological and molecular response of small intestine to lactulose and hydrogen-rich water in female piglets fed Fusarium mycotoxins contaminated diet

Background: Following the intake of Fusarium mycotoxin-contaminated feed,small intestines may be exposed to high levels of toxic substances that can potentially damage intestinal functions in livestock.It is well known that Fusarium mycotoxins will lead a breakdown of the normally impeccable epithelial barrier,resulting in the development of a "leaky" gut.H2 administration with different methods has been proved definitely potentials to prevent serious intestinal diseases.The goal of this study is to investigate the roles of lactulose(LAC) and hydrogenrich water(HRW) in preventing intestinal dysfunction in piglets fed Fusarium mycotoxin-contaminated feed.Methods: A total of 24 female piglets were evenly assigned to 4 groups: negative control(NC) group,mycotoxincontaminated(MC) feed group,MC feed with LAC treatment(MC + LAC),and MC feed with HRW treatment(MC +HRW),respectively.Piglets in the NC group were fed uncontaminated control diet,while remaining piglets were fed Fusarium mycotoxin-contaminated diet.For the NC and MC groups,10 mL/kg body weight(BW) of hydrogen-free water(HFW) was orally administrated to piglets twice daily;while in the MC + LAC and MC + HRW groups,piglets were treated with the same dose of LAC solution(500 mg/kg BW) and HRW twice daily,respectively.On d 25,serum was collected and used for biochemical analysis.Intestinal tissues were sampled for morphological examination as well as relative genes and protein expression analysis.Results: Our data showed that Fusarium mycotoxins induced higher serum diamine oxidase(DAO) activities(P < 0.05),D-lactic acid levels(P < 0.01),and endotoxin status(P < 0.01),lower villus height(P < 0.01) and ratio of villus height to crypt depth(P < 0.05) in small intestine,greater apoptosis index and higher mRNA expression related to tight junctions(P < 0.05).In addition,the distribution and down-regulation of claudin-3(CLDN3) protein in the small intestinal was also observed.As expected,oral administrations of HRW and LAC were found to remarkably provide beneficial effects against Fusarium mycotoxin-induced apoptosis and intestinal leaking.Moreover,either HRW or LAC treatments were also revealed to prevent abnormal intestinal morphological changes,disintegrate tight junctions,and restore the expression and distribution of CLDN3 protein in the small intestinal mucosal layer in female piglets that were fed Fusarium mycotoxins contaminated diet.Conclusions: Our data suggest that orally administrations of HRW and LAC result in less Fusarium mycotoxininduced apoptosis and leak in the small intestine.Either HRW or LAC treatments could prevent the abnormal changes of intestinal morphology and molecular response of tight junctions as well as restore the distribution and expression of CLDN3 protein of small intestinal mucosa layer in female piglets that were fed Fusarium mycotoxins contaminated diet.

Protective effects of Ligustrazine,Kakonein and Panax Notoginsenoside on the small intestine and immune organs of rats with severe acute pancreatitis

BACKGROUND:Severe acute pancreatitis (SAP) is characterized by fatal pathogenic conditions and a high mortality.It is important to study SAP complicated with multiple organ injury.In this study we compared the protective effects of three traditional Chinese medicines (Ligustrazine,Kakonein and Panax Notoginsenoside) on the small intestine and immune organs (thymus,spleen and lymph nodes) of rats with SAP and explored their mechanism of action.METHODS:One hundred forty-four rats with SAP were randomly divided into model control,Ligustrazine-treated,Kakonein-treated,and Panax Notoginsenoside-treated groups (n=36 per group).Another 36 normal rats comprised the sham-operated group.According to the different time points after operation,the experimental rats in each group were subdivided into 3-,6-and 12-hour subgroups (n=12).At various time points after operation,the mortality rate of rats and pathological changes in the small intestine and immune organs were recorded and the serum amylase levels were measured.RESULTS:Compared to the model control groups,the mortality rates in all treated groups declined and the pathological changes in the small intestine and immune tissues were relieved to different degrees.The serum amylase levels in the three treated groups were significantly lower than those in the model control group at 12 hours.The pathological severity scores for the small intestinal mucosa,thymus and spleen (at 3 and 12 hours) in the Ligustrazine-treated group,for the thymus (at 3 and 12 hours) and spleen (at 3 and 6 hours) in the Kakonein-treated group,and for the thymus (at 3 hours)and spleen (at 3 hours) in the Panax Notoginsenoside-treated group were significantly lower than those in the model control group.The pathological severity scores of the small intestinal mucosa (at 6 and 12 hours) and thymus (at 6 hours) in the Ligustrazine-treated group were significantly lower than those in the Kakonein-and Panax Notoginsenoside-treated groups.CONCLUSIONS:All the three traditional Chinese drugs significantly alleviated the pathological changes in the small intestine and immune organs of SAP rats.Ligustrazine was the most effective one among them.

Effects of psychological stress on small intestinal motility and expression of cholecystokinin and vasoactive intestinal polypeptide in plasma and small intestine in mice

AIM: To investigate the effects of psychological stress on small intestinal motility and expression of cholecystokinin (CCK) and vasoactive intestinal polypeptide (VIP) in plasma and small intestine, and to explore the relationship between small intestinal motor disorders and gastrointestinal hormones under psychological stress. METHODS: Thirty-six mice were randomly divided into psychological stress group and control group. A mouse model with psychological stress was established by housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. CCK and VIP levels in plasma and small intestine in mice were measured by radioimmunoassay (RIA). RESULTS: Small intestinal transit was inhibited (52.18±19.15% vs70.19±17.79%, P<0.01) in mice after psychological stress, compared to the controls. Small intestinal CCK levels in psychological stress mice were significantly lower than those in the control group (0.75±0.53 μg/g vs1.98±1.17 μg/g, P<0.01), whereas plasma CCK concentrations were not different between the groups. VIP levels in small intestine were significantly higher in psychological stress mice than those in the control group (8.45±1.09 μg/g vs7.03±2.36 μg/g, P<0.01), while there was no significant difference in plasma VIP levels between the two groups. CONCLUSION: Psychological stress inhibits the small intestinal transit, probably by down-regulating CCK and up-regulating VIP expression in small intestine.

Giant primary angiosarcoma of the small intestine showing severe sepsis

Primary malignant tumors of the small intestine are rare, comprising less than 2% of all gastrointestinal tumors. An 85-year-old woman was admitted with fever of 40&#x02005;&#x02005;&#x000b0;C and marked abdominal distension. Her medical history was unremarkable, but blood examination showed elevated inflammatory markers. Abdominal computed tomography showed a giant tumor with central necrosis, extending from the epigastrium to the pelvic cavity. Giant gastrointestinal stromal tumor of the small intestine communicating with the gastrointestinal tract or with superimposed infection was suspected. Because no improvement occurred in response to antibiotics, surgery was performed. Laparotomy revealed giant hemorrhagic tumor adherent to the small intestine and occupying the peritoneal cavity. The giant tumor was a solid tumor weighing 3490 g, measuring 24 cm &#x000d7; 17.5 cm &#x000d7; 18 cm and showing marked necrosis. Histologically, the tumor comprised spindle-shaped cells with anaplastic large nuclei. Immunohistochemical studies showed tumor cells positive for vimentin, CD31, and factor VIII-related antigen, but negative for c-kit and CD34. Angiosarcoma was diagnosed. Although no postoperative complications occurred, the patient experienced enlargement of multiple metastatic tumors in the abdominal cavity and died 42 d postoperatively. The prognosis of small intestinal angiosarcoma is very poor, even after volume-reducing palliative surgery.

Opiate-induced constipation related to activation of small intestine opioid μ2-receptors

AIM： To investigate the role of opioid p-receptor subtype in opiate-induced constipation （OIC）.METHODS： The effect of Ioperamide on intestinal transit was investigated in mice. Ileum strips were isolated from 12-wk-old male BALB/c mice for identification of isometric tension. The ileum strips were precontracted with 1 μmol/L acetylcholine （ACh）. Then, decrease in muscle tone （relaxation） was characterized after cumu- lative administration of 0.1-10μ~mol/L Ioperamide into the organ bath, for a concentration-dependent study. Specific blockers or antagonists were used for pretreat- ment to compare the changes in Ioperamide-induced relaxation.RESULTS： In addition to the delay in intestinal transit, Ioperamide produced a marked relaxation in isolated ileum precontracted with ACh, in a dose-dependent manner. This relaxation was abolished by cyprodime,a selective opioid p-receptor antagonist, but not modified by naloxonazine at a dose sufficient to block opioid μ-1 receptors. Also, treatment with opioid μ-1 receptor agonist failed to modify the muscle tone. Moreover, the relaxation by Ioperamide was attenuated by glibenclamide at a dose sufficient to block ATP-sensitive K^＋ （KATP） channels, and by protein kinase A （PKA） inhibitor, but was enhanced by an inhibitor of phosphodiesterase for cyclic adenosine monophosphate （cAMP）.CONCLUSION： Loperamide induces intestinal relaxa- tion by activation of opioid μ-2 receptors via the cAMP- PKA pathway to open KATp channels, relates to OIC.

Epidemiology of cancer of the small intestine

Cancer of the small intestine is very uncommon.There are 4 main histological subtypes:adenocarcinomas,carcinoid tumors,lymphoma and sarcoma.The incidence of small intestine cancer has increased over the past several decades with a four-fold increase for carcinoid tumors,less dramatic rises for adenocarcinoma and lymphoma and stable sarcoma rates.Very little is known about its etiology.An increased risk has been noted for individuals with Crohn's disease,celiac disease,adenoma,familial adenomatous polyposis and Peutz-Jeghers syndrome.Several behavioral risk factors including consumption of red or smoked meat,saturated fat,obesity and smoking have been suggested.The prognosis for carcinomas of the small intestine cancer is poor(5 years relative survival < 30%),better for lymphomas and sarcomas,and best for carcinoid tumors.There has been no signif icant change in longterm survival rates for any of the 4 histological subtypes.Currently,with the possible exceptions of obesity and cigarette smoking,there are no established modifiable risk factors which might provide the foundation for a prevention program aimed at reducing the incidence and mortality of cancers of the small intestine.More research with better quality and sufficient statistical power is needed to get better understanding of the etiology and biology of this cancer.In addition,more studies should be done to assess not only exposures of interest,but also host susceptibility.

Titanium dioxide induced inflammation in the small intestine

AIM:To investigate the effects of titanium dioxide (TiO2) nanoparticles (NPTiO 2 ) and microparticles (MPTiO 2 ) on the inflammatory response in the small intestine of mice. METHODS: Bl 57/6 male mice received distilled water suspensions containing TiO 2 (100 mg/kg body weight) as NPTiO 2 (66 nm), or MPTiO 2 (260 nm) by gavage for 10 d, once a day; the control group received only distilled water. At the end of the treatment the duodenum, jejunum and ileum were extracted for assessment of cytokines, inflammatory cells and titanium content. The cytokines interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, tumor necrosis factor-α (TNF-α), intracellular interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were evaluated by enzyme-linked immunosorbent assay in segments of jejunum and ileum (mucosa and underlying muscular tissue). CD4 + and CD8 + T cells, natural killer cells, and dendritic cells were evaluated in duodenum, jejunum and ileum samples fixed in 10% formalin by immuno-histochemistry. The titanium content was determined by inductively coupled plasma atomic emission spectrometry. RESULTS: We found increased levels of T CD4 + cells (cells/mm 2 ) in duodenum:NP 1240 ± 139.4, MP 1070 ± 154.7 vs 458 ± 50.39 (P < 0.01); jejunum:NP 908.4 ± 130.3, MP 813.8 ± 103.8 vs 526.6 ± 61.43 (P < 0.05); and ileum:NP 818.60 ± 123.0, MP 640.1 ± 32.75 vs 466.9 ± 22.4 (P < 0.05). In comparison to the control group, the groups receiving TiO 2 showed a statistically significant increase in the levels of the inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ and TGF-β. The cytokine production was more pronounced in the ileum (mean ± SE):IL-12: NP 33.98 ± 11.76, MP 74.11 ± 25.65 vs 19.06 ± 3.92 (P < 0.05); IL-4: NP 17.36 ± 9.96, MP 22.94 ± 7.47 vs 2.19 ± 0.65 (P < 0.05); IL-23: NP 157.20 ± 75.80, MP 134.50 ± 38.31 vs 22.34 ± 5.81 (P < 0.05); TNFα: NP 3.71 ± 1.33, MP 5.44 ± 1.67 vs 0.99± 019 (P < 0.05); IFNγ: NP 15.85 ± 9.99, MP 34.08 ± 11.44 vs 2.81 ± 0.69 (P < 0.05); and TGF-β: NP 780.70 ± 318.50, MP 1409.00 ± 502.20 vs 205.50 ± 63.93 (P < 0.05). CONCLUSION:Our findings indicate that TiO2 particles induce a Th1-mediated inflammatory response in the small bowel in mice.