[Healthy China Strategy and schistosomiasis control].

This paper summarizes the changes in the policy associated with schistosmiasis control in the new era, analyzes the background of Health China Strategy and its association with the current schistosomiasis control program in China, describes several schistosomiasis control models and proposes some suggestions responding to the challenges in current schistosomiasis control program of China, so as to provide insights into the development of the effective control strategy for schistosomiasis.

Hsa-miR-10a-5p promotes pancreatic cancer growth by BDNF/SEMA4C pathway.

This article aims to explore the expression and mechanism of miR-10a-5p in pancreatic cancer. MiR-10a-5p mimic, MiR-10a-5p inhibitor and negative control were transfected into human pancreatic cancer cell line SW1990. Real-time quantitative PCR technology was used to analyze the expression level of miR-10a-5p in pancreatic cancer tissues and cells. The proliferation, invasion and apoptosis of SW1990 cells in each group were detected by CCK-8 analysis, Transwell analysis, TUNEL method and flow cytometry. Targetscan7.2 was used to predict the target protein of MiR-10a-5p, and the expression of related proteins was detected by Western blot analysis. The results showed that the expression of miR- 10a-5p in cancer tissues of patients with pancreatic cancer was significantly higher than that in adjacent tissues (P <0.05). The expression of miR-10a-5p in cancer cells increased significantly, which could promote the proliferation and invasion of SW1990 cells and inhibit apoptosis (P <0.05). Overexpression of miR-10a-5p can regulate the expression of BDNF and SEMA4C. miR-10a-5p can promote the occurrence and development of pancreatic cancer by regulating the BDNF / SEMA4C pathway, and may become a molecular target for the diagnosis and treatment of pancreatic cancer in the future.

[Willingness and influencing factors of using pre-exposure prophylaxis among 301 men have sex with men in Wuhan city, 2015].

Objective: To understand willingness and influencing factors of using pre-exposure prophylaxis (Pr-EP) among men who have sex with men (MSM). Methods: Snow ball sampling was employed to recruit MSM in the social spaces (like bars and bathrooms) with focused activities by MSM and internet (QQ and Wechat) in Wuhan between August and November, 2015. 304 MSM were considered eligible when they were self-identified MSM and has had sex with men in the previous 12 months, over the age of 18 and have full civil liability. On-site and online questionnaire surveys were conducted by self-designed questionnaires to collect information including demographic characteristics, sexual risks and practices, awareness of PrEP, and willingness to use PrEP. A total of 301 qualified questionnaires were obtained. Multivariate logistic regression models were constructed to identify factors associated with willingness to use Pr-EP. Results: The mean age of surveyed MSM were (27.51±8.31) years, between18-61. 149 on-site survey, online were152; 131 MSM have regular homosexual partners, 170 MSM have not regular homosexual partners. Only 17.28% (52/301) had heard of Pr-EP before this survey, 18.32% (24/130) had heard of Pr-EP among those who had regular homosexual partners and those who had not accounted for 16.47% (28/170). 74.42% (224/301) had willingness to use Pr-EP after they knew Pr-EP was safe and effective through the survey. The proportion among those who had regular homosexual partners was 74.05%(74), and the proportion among those who had not was 74.71% (127); Among those who had regular homosexual partners, results suggested that those who were married/cohabiting were more likely to report a willingness to use PrEP compared to unmarried/divorced or widowed (OR=5.60), compared with homosexual, heterosexuality was associated with decreased odds of willingness to use Pr-EP (OR= 0.22), compared with HIV status of sexual partner was negative or uncertain, positive infection status was associated with increased odds of willingness to use (OR=7.52). Compared with MSM who have not regular homosexual partners, those who were married/cohabiting were more likely to report a willingness to use PrEP compared to unmarried/divorced or widowed (OR=9.09), compared with those who think they have risk of infection, those who do not think they have risk of infection was associated with decreased odds of willingness to use Pr-EP (OR= 0.30), compared with those with a high frequency to seek sexual partners, those not often to seek was associated with decreased odds of willingness to use Pr-EP (OR= 0.27). All above P values were<0.05. Conclusion: The awareness rate of Pr-EP among MSM in Wuhan is low in 2015, but the willingness to use Pr-EP could get a considerable increase after introduction. It is considered that promotion of Pr-EP is feasible in China, and there are different influencing factors for the willingness between two MSM subgroups (having regular homosexual partners and having no regular homosexual partners).

Immunisation status and determinants of left-behind children aged 12-72 months in central China.

Many parents move from rural China to urban areas in search of job opportunities, and leave their children behind to be raised by relatives. We aimed to assess the immunisation coverage, including the 1:3:3:3:1 vaccine series (one dose of Bacilli Chalmette-Guérin vaccine; three doses of live attenuated oral poliomyelitis vaccine; three doses of diphtheria, tetanus and pertussis combined; three doses of hepatitis B vaccine; and one dose of measles-containing vaccine), in children aged 12-72 months and identify the determinants of immunisation uptake among left-behind children in Hubei Province, Central China, in 2014. In this cross-sectional study using the World Health Organization's cluster sampling technique, we surveyed 1368 children from 44 villages in 11 districts of Hubei Province. The socio-demographic and vaccination status data were collected by interviewing primary caregivers using a semi-structured questionnaire and reviewing the immunisation cards of the children. Univariate and multivariate analyses were used to identify the determinants of complete vaccination and age-appropriate vaccination. For each dose of the five vaccines, the vaccination coverage in the left-behind and non-left-behind children was >90%; however, the age-appropriate vaccination coverage for each vaccine was lower in left-behind than in non-left-behind children. For the five vaccines, the fully vaccinated rate of left-behind children were lower than those of non-left-behind children (89·1%, 92·7%; P = 0·013) and age-appropriate immunisation rate of left-behind children were lower than those of non-left-behind children (65·7%, 79·9%; P < 0·001). After controlling for potential confounders, we found that the parenting pattern, annual household income and attitude of the primary caregiver towards vaccination significantly influenced the vaccination status of children. Moreover, we noted a relatively high prevalence of delayed vaccination among left-behind children. Hence, we believe that the age-appropriate immunisation coverage rate among left-behind children in rural areas should be further improved by delivering and sustaining primary care services.

Exploratory social network analysis and gene sequencing in people who inject drugs infected with hepatitis C virus.

Social networks facilitate the transmission of hepatitis C virus (HCV) in people who inject drugs (PWID). The aim of this study was to assess how certain network structural characteristics are related to HCV infections in PWID and to determine the most susceptible individuals for HCV transmission in a network of PWID. PWID (N = 80) from central China were recruited from a previous follow-up case-control study. Demographic and behavioural information was obtained from a computerized database for each group. HCV RNA was extracted from blood specimens. Sequences were used to construct a phylogenetic tree and to determine genetic distances. Socio-metric social links were established between participants. Network measures were calculated using UCINET. Three HCV genotypes were identified, covering five subtypes. The density of the social networks for the whole sample (N = 80), case group (n = 31) and control group (n = 49) was 0.038, 0.054 and 0.008, respectively. PWID infected with HCV were in frequent contact with others within their group. There were four pairs of nodes with genotypic distances of 0.000 that were identified and clustered in subtypes 6a and 1b; each subject pair was linked and found in one clique. Three of the five most active nodes were infected with HCV. These three nodes served as a bridge, contributing to the connection of other nodes. These findings identify susceptible individuals for HCV transmission in PWID based on their frequent contact with others in the network. These results provide data that could be used for modelling HCV transmission patterns and in public health policies.

Injection of frozen-thawed porcine first polar bodies into enucleated oocytes results in fertilization and embryonic development.

The objective was to determine whether enucleated oocytes injected with frozen porcine first polar bodies (pPB1s) could be fertilized and developed into viable embryos in vitro. Metaphase II (MII) oocytes with pPB1s were frozen (vitrified) and stored for 2 mo. The pPB1s were isolated from thawed MII oocytes and injected into enucleated recipient oocytes by micromanipulation. All recipients injected with thawed pPB1s were fertilized by intracytoplasmic sperm injection (ICSI), and the resulting recombinant zygotes were incubated to assess their developmental competence in vitro. Furthermore, double-antibody immunohistochemistry was used to verify that the nucleus of the pPB1 participated in fertilization and supported embryonic development. Porcine embryos (2- to 8-cell stage) were obtained from the recombinants. The average in vitro cleavage rate of 2-, 4-, and 8-cell stage recombinant embryos was 25.3, 17.7, and 9.3% (P < 0.05), respectively. Chromosomes in the labeled pPB1 participated in the formation of the two blastomere nuclei of 2-cell stage embryos derived from recombinant oocytes. In conclusion, nuclear materials of frozen-thawed pPB1 supported oocyte fertilization and subsequent embryonic development, thereby providing a new way to use frozen PB1s for preservation and reproduction of mammals.

Use of genotypic selection to detect P53 codon 273 CGT>CTT transversion: application to an occupationally exposed population.

CGT>CTT transversion in codon 273 of the P53 tumor-suppressor gene is one of the major mutations detected in human tumors. Within an epidemiological framework, we investigated the use of a genotypic selection method to measure this point mutation. The allele-specific polymerase chain reaction (AS-PCR) that was developed was able to detect 10 mutant copies of the gene among a total of 5 x 10(5) wild-type copies. We used this assay to detect CGT>CTT transversions in buccal cell DNA of production workers (n=76) from a viscose factory exposed to carbon disulfide (amongst other pollutants) and in the DNA of non-exposed office workers (n=67). The mutation appeared more frequently in the exposed than in the non-exposed worker who were smokers. The results of the study indicate that occupational exposure results in a significant increase in P53 CGT>CTT transversions and more especially identified occupational exposure in combination with smoking as a significant risk factor for the mutation. We conclude that AS-PCR of the P53 273rd codon transversions is a suitable technique for studying the effects of occupational exposure.

Transcription factor NF-kappaB signals antianoikic function of trefoil factor 3 on intestinal epithelial cells.

Transcription factor NF-kappaB has both pro-apoptotic and anti-apoptotic properties depending on the cell type. Its role in the intestinal epithelial cell has not been well elucidated. Trefoil factor 3 (TFF3) is an anti-apoptotic peptide secreted by intestinal goblet cells. Here we show that TFF3 activated NF-kappaB p50/p65 heterodimer within 1 h in IEC-18 cells (a nontransformed rat intestinal epithelial cell line). Moreover, we found that TFF3-treated IEC-18 cells are resistant to anoikis, an anchorage-related apoptosis in epithelium. In addition, the stable expression of a mutant form of the endogenous NF-kappaB inhibitor (IkappaBalpha(mut)) in IEC-18 cells results in a significant attenuation of anti-anoikic effect of TFF3. Taken together, these data indicate that (1) TFF3 is an endogenous gastrointestinal peptide with anti-anoikic property; (2) TFF3 activates NF-kappaB in enterocytes; and (3) TFF3-induced resistance to anoikis in intestinal epithelial cells is mediated by a distinct signaling cascade linked to NF-kappaB. Furthermore, our study implicates NF-kappaB as an important regulator in survival pathway of intestinal epithelial cells.

Prostanoids mediate the protective effect of trefoil factor 3 in oxidant-induced intestinal epithelial cell injury: role of cyclooxygenase-2.

Trefoil factors are small peptides found in several mammalian tissues including gut, respiratory tract and brain. Their physiological function is not well understood. Among them, trefoil factor 3 (intestinal trefoil factor) is known to be cytoprotective in the gut. However, the molecular mechanism and secondary mediators of trefoil factor 3 action are not known. In the present study, we examined whether the cyclooxygenase pathway is involved in trefoil factor 3 action. We showed that trefoil factor 3 significantly induces the production of prostaglandin E(2) and prostaglandin I(2) in IEC-18 cells (an intestinal epithelial cell line) in a dose dependent manner. Western blot and immunohistochemistry revealed that trefoil factor 3 (2.5 microM) up-regulates the expression of cyclooxygenase-2 but not cyclooxygenase-1 in IEC-18 cells. Treating cells with trefoil factor 3 (10 microM) significantly attenuated reactive oxygen species-induced IEC-18 cell injury. This effect is blocked by NS-398 (10 microM), a selective cyclooxygenase-2 inhibitor. Moreover, we demonstrated that exogenously administered carbacyclin (1 microM, a stable analogue of prostaglandin I(2)) and/or prostaglandin E(2) (1 microM) caused a significant reduction of reactive oxygen species-induced cell injury, mimicking the effect of trefoil factor 3. In summary, our results indicate that trefoil factor 3 activates cyclooxygenase-2 in intestinal epithelium to produce prostaglandin I(2) and prostaglandin E(2), which function as survival factors and mediate the cytoprotective action of trefoil factor 3 against oxidant injury.

Platelet-activating factor increases mucosal permeability in rat intestine via tyrosine phosphorylation of E-cadherin.

1. Platelet-activating factor (PAF), an inflammatory mediator, plays an important role in mediating intestinal injury. However, it remains unclear whether PAF has a function in the intestine. The production of PAF by normal intestine and by unstimulated intestinal epithelial cell lines suggests that PAF may have a regulatory function in the normal bowel. 2. In this study we investigated the role of PAF in modulating intestinal mucosal permeability in rats. Lumen-to-blood transit of FD-4 (dextran 4400), (an index of intestinal permeability), was assessed in sham-operated rats and rats injected with PAF (1.25 microg kg(-1), i.v., a dose insufficient to induce intestinal injury). 3. PAF-induced villus cytoskeletal changes were examined by staining the intestine for F-actin. The effect of PAF on tyrosine phosphorylation of the junctional protein E-cadherin was examined by immunoprecipitation. Some rats were pretreated with AG1288 (a tyrosine kinase inhibitor) before PAF injection, and mucosal permeability change was assessed. 4. To investigate the role of endogenous PAF upon mucosal permeability, we studied the effect of PAF antagonists on (intraluminal) glucose-induced increase in mucosal permeability. 5. We found that low dose PAF: (a) alters the cytoskeletal structure of intestinal epithelium, (b) causes the influx of FD4 from intestinal lumen to systemic circulation, (c) induces tyrosine phosphorylation of E-cadherin and cadherin-associated proteins. Glucose-induced mucosal permeability increase is abolished by using two structurally different PAF antagonists. 6. These results suggest that endogenous PAF modulates macromolecular movement across the intestinal mucosal barrier, probably via tyrosine phosphorylation of E-cadherin and cytoskeletal alteration of enterocytes.

Lipopolysaccharide activates nuclear factor kappaB in rat intestine: role of endogenous platelet-activating factor and tumour necrosis factor.

1. We examined the effect of lipopolysaccharide (LPS), a cell wall constituent of Gram negative bacteria, on nuclear factor kappaB (NF-kappaB) activation in the intestine and the roles of endogenous platelet-activating factor (PAF), tumour necrosis factor-alpha (TNF) and neutrophils. We also compared the time course of NF-kappaB activation in response to PAF and LPS. 2. Ileal nuclear extracts from LPS (8 mg kg(-1), IV)-injected rats were assayed for NF-kappaB-DNA-binding activity and identification of the subunits. Some rats were pretreated with WEB2170 (a PAF receptor antagonist), anti-TNF antibody, or anti-neutrophil antiserum. NF-kappaB p65 was localized by immunohistochemistry. An additional group was challenged with PAF (2 microg kg(-1), IV) for comparison. 3. LPS activates intestinal NF-kappaB, both as p50-p50 and p50-p65 dimers within 15 min, and the effect peaks at 2 h. The effect is slower and more sustained than that of PAF, which peaks at 30 min. Activated NF-kappaB was immunolocalized within epithelial and lamina propria cells. LPS effect was reduced by 41, 37 and 44%, respectively, in animals pretreated with WEB2170, anti-TNF antibody, or anti-neutrophil antiserum (P<0.05). 4. LPS activates intestinal NF-kappaB in vivo and neutrophil activation is involved in its action. The LPS effect is mediated by both endogenous PAF and TNF.

Intestinal trefoil factor binds to intestinal epithelial cells and induces nitric oxide production: priming and enhancing effects of mucin.

Intestinal trefoil factor (ITF or TFF3), NO and epithelium-associated mucin have important roles in sustaining mucosal integrity in the gastrointestinal tract. In the present study we examined ITF-binding molecules on IEC-18 cells (an intestinal epithelial cell line) with the use of flow cytometry and localized these molecules on the cell surface by confocal microscopy. Furthermore, we studied the interaction of mucin and ITF and their co-operative effect on NO production by the epithelium. Stimulation of cells with mucin (5 mg/ml) for 90 min resulted in a 5-fold increase in ITF binding. Treatment of IEC-18 cells with actinomycin D or cycloheximide attenuated mucin-enhanced ITF binding. Ligand blot analysis confirmed the induction of ITF-binding protein in IEC-18 cells by mucin. These results indicate that transcriptional and translational mechanisms are involved in the effect of mucin. Treatment with ITF overnight resulted in a low level of nitrite production by the cells, a 5-fold increase over control, in a concentration-dependent manner. ITF-induced NO production was attenuated by 1400W, a selective type II nitric oxide synthase (NOS2) inhibitor. By immunoblotting we found that NOS2 was up-regulated by ITF treatment. Priming IEC-18 cells with mucin for 90 min enhanced the effect of ITF on NO production, suggesting that the up-regulation of ITF-binding molecules by mucin might be physiologically relevant. Taken together, these observations indicate (1) that ITF-binding molecules that are up-regulated by mucin exist on the intestinal epithelial surface, and (2) that ITF modulates epithelial NO production via the NOS2 pathway, which is enhanced by mucin.

Roles of nitric oxide synthases in platelet-activating factor-induced intestinal necrosis in rats.

OBJECTIVE: To examine the role of constitutive and inducible nitric oxide synthases (cNOS and iNOS) in platelet-activating factor (PAF)-induced shock and intestinal injury. DESIGN: Prospective, randomized, controlled experimental study. SETTING: Hospital research laboratory. SUBJECTS: Young adult male Sprague-Dawley rats were anesthetized and studied. INTERVENTIONS: Rats were injected with PAF, either alone or after the following pretreatments: a) selective iNOS inhibitors aminoguanidine or S-methylisothiourea; b) 3-morpholinosydnonimine, a NO donor; c) S-methylisothiourea + 3-morpholinosydnonimine; and d) antineutrophil antibody (to deplete neutrophils). MEASUREMENTS AND MAIN RESULTS: Blood pressure, hematocrit, white blood cell counts, intestinal injury, and intestinal cNOS and iNOS activities were assessed. We found that: a) cNOS is the predominant NOS in the intestine and its activity is inversely correlated to the level of tissue injury; b) there is a time-dependent increase in cNOS activity in sham-operated animals, which was abolished by PAF; c) Western blotting and immunohistochemistry showed iNOS present in the normal intestine, localizing mainly in crypt cells; d) iNOS inhibitors attenuated PAF-induced injury in animals with high cNOS activity, but had no protective effect in animals with low cNOS activity; e) 3-morpholinosydnonimine, alone or together with S-methylisothiourea, alleviated PAF-induced injury; and f) neutrophil depletion blocked the suppressive effect of PAF on cNOS and prevented injury. CONCLUSIONS: We conclude that cNOS and iNOS play different roles in PAF-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of iNOS inhibitors.

Rapid growth of cutaneous metastases after surgical resection of thrombospondin-secreting small blue round cell tumor of childhood.

In animal models, the importance of tumor-derived antiangiogenic factors in controlling metastases has been demonstrated by the growth acceleration of distant metastases after surgical excision of a primary tumor mass. We report the case of an infant who developed rapidly growing cutaneous metastases after surgical resection of a neoplasm of an upper extremity. The tumor was undifferentiated, with some morphological features of primitive neuroectodermal tumor. To test the possibility that the primary tumor was secreting an angiogenic inhibitor, cells from the primary tumor were grown in culture, and the culture medium was tested with an in vitro endothelial cell migration assay and Western blot. The cultured cells secreted sufficiently high levels of an angiogenic inhibitor to overcome the inducing ability of vascular endothelial growth factor and basic fibroblast growth factor. One of the secreted proteins was thrombospondin-1, a potent antiangiogenic glycoprotein. The rapid dissemination of distant metastases after resection of the primary tumor in this case suggests that tumor-derived angiogenic inhibitors are important in maintaining the local net balance of angiogenic mediators controlling the growth of micrometastasis.

Intestinal NF-kappaB is activated, mainly as p50 homodimers, by platelet-activating factor.

NF-kappaB, a transcription factor, upregulates gene transcription of many inflammatory mediators. Here, we examined the activity of NF-kappaB in the rat small intestine, and how it may be affected by platelet-activating factor (PAF), an important mediator for intestinal injury and inflammation. Ileal nuclear extracts from sham-operated and PAF (1.5 microg/kg)-injected rats were prepared for the assessment of NF-kappaB DNA-binding activity, and the identification of NF-kappaB subunits. The experiment was also performed on neutrophil-depleted rats to examine whether the PAF effect is neutrophil-dependent. Cellular NF-kappaB was localized by immunohistochemistry. We found that: (a) NF-kappaB is constitutively active in rat small intestine; (b) PAF at a dose below that causing shock and bowel necrosis enhances DNA-binding activity of NF-kappaB within 30 min after injection; activated NF-kappaB contains predominantly p50 subunits; (c) immunohistochemistry showed that PAF induced translocation of p50 into the nucleus of cells of the lamina propria, as well as of the epithelium; and (d) the effect of PAF is abrogated by neutrophil depletion, suggesting a role of neutrophils in NF-kappaB activation. Our study suggests that NF-kappaB is weakly active constitutively in the intestine, and inflammatory stimuli such as PAF activate NF-kappaB and enhance its DNA-binding activity in the intestine, which contains predominantly p50 subunits.

Platelet-activating factor (PAF) up-regulates plasma and tissue PAF-acetylhydrolase activity in the rat: effect of cycloheximide.

Platelet-activating factor (PAF) is a proinflammatory phospholipid mediator implicated in necrotizing enterocolitis. Regulation of PAF-acetylhydrolase (AH), the enzyme degrading PAF, is poorly understood. In this study we found that administration of a dose of PAF (1.5 microg/kg, i.v.), which does not cause gross intestinal injury, increased plasma and intestinal PAF-AH in the rat. Cycloheximide (CHX, 5 mg/kg, i.v.) reduced the activity of plasma (but not intestinal tissue) AH in control, as well as in PAF-injected rats, and aggravated systemic inflammation and tissue injury in the latter. The intestinal necrosis induced by PAF and CHX was ameliorated by posttreatment with WEB2170 (a PAF antagonist), indicating a role of endogenous PAF in mediating injury. Both WEB2170 and anti-TNF antibody reduced PAF-induced AH activity in intestinal tissue, but not in the plasma. Allopurinol largely prevented the injury induced by PAF and CHX, but had no effect on the up-regulation of AH. We conclude: 1) de novo protein synthesis is required to maintain physiologic AH level in the plasma; 2) PAF up-regulates plasma and intestinal AH activity; 3) CHX enhances the injurious effect of PAF; 4) endogenous PAF and TNF also play a role in the up-regulation of intestinal AH; the former probably mediating the intestinal injury by PAF; and 5) reactive oxygen species may mediate the injurious effect of PAF plus CHX, but do not contribute to the regulation of AH by PAF.

Characterization of a putative receptor for intestinal trefoil factor in rat small intestine: identification by in situ binding and ligand blotting.

Intestinal trefoil factor (ITF), a small peptide secreted by intestinal goblet cells, maintains mucosal integrity and promotes epithelial wound healing. Although ITF has been cloned, the detailed mechanism by which ITF interacts with intestinal epithelium remains elusive. In the present study, we expressed mature rat ITF (rITF) with pXa (a prokaryotic expression vector) in Escherichia coli to generate a biotinylated rITF fusion protein (bTag-ITF). By using bTag-ITF probe, we identified ITF binding cells in the crypts of the small intestine and mucous cells of the region of gastric glands. Using a ligand blotting technique, we further characterized a 50 kDa glycosylated protein from the membrane fraction of the small intestine, which bound to bTag-ITF. Our data suggest that this 50 kDa membrane glycoprotein is a putative receptor for ITF in the gastrointestinal tract.

Platelet activating factor and endotoxin increase the enzyme activity and gene expression of type II phospholipase A2 in the rat intestine. Role of polymorphonuclear leukocytes.

Type II phospholipase A2 (PLA2-II) may regulate eicosanoid synthesis; is involved in various inflammatory processes, septic shock, and inflammatory bowel disease; and is up-regulated by LPS and inflammatory cytokines in vitro. We have previously shown that the platelet-activating factor (PAF)-induced intestinal injury is attenuated by peptido-leukotriene antagonists, suggesting a role of PLA2. The purpose of this study is to examine the regulation of intestinal PLA2-II by PAF and LPS. Using synthesized competitor RNA as competitor, we quantified PLA2-II transcripts by competitive reverse transcription-PCR. We found that PLA2-II gene is constitutively expressed in the rat ileum. PAF at a dose (1.5 micrograms/kg) below that causing intestinal injury rapidly up-regulated intestinal PLA2-II at both transcriptional and post-transcriptional levels, almost tripling its transcripts and significantly increasing enzyme activity in 30 min. LPS (5 mg/kg) also up-regulated PLA2-II. This effect could not be blocked by PAF antagonist. Depletion of circulating polymorphonuclear leukocytes (PMNs) abolished the effect of PAF on PLA2-II gene expression and enzyme activation. In contrast, PMN depletion prevented LPS-induced PLA2-II enzyme activity but enhanced the gene expression. We conclude that: 1) both PAF and LPS induce gene transcription and enzyme activation of PLA2-II in the small intestine; 2) PAF up-regulates PLA2-II via PMN activation; 3) LPS effect is independent of endogenous PAF formation; and 4) different pathways exist for PAF and LPS in the regulation of intestinal PLA2-II gene expression in vivo.

Primary hepatic neuroendocrine carcinoma in a child. Morphologic, immunocytochemical, and molecular biologic studies.

BACKGROUND: Primary neuroendocrine tumor of the liver is uncommon, and virtually all reported patients with the tumor have been adults. Most of the tumors were carcinoids. The authors report an 8-year-old girl with primary hepatic neuroendocrine carcinoma. METHODS: Histologic, ultrastructural, and immunocytochemical studies and Southern blot analysis of tumor N-myc DNA were performed in the patient. RESULTS: Histologically, the tumor revealed a characteristic organoid pattern with a spectrum of differentiation varying from well-differentiated carcinoid-like areas to poorly differentiated pleomorphic areas. Ultrastructural features included neurosecretory granules and interdigitating cytoplasmic extensions. The tumor cells showed immunoreactivity to neuron-specific enolase (NSE), S-100 protein, chromogranin, and synaptophysin. No evidence of amplification of tumor N-myc DNA was present. However, the molecular weight of the tumor N-myc DNA (1.8 kb) was significantly lower than the normal control (from normal liver tissue) (2.0 kb). CONCLUSIONS: This report documents the occurrence of primary hepatic neuroendocrine carcinoma in a child. Thorough studies and complete clinical evaluation are essential to the establishment of diagnosis. The result of N-myc DNA analysis probably is attributable to deletion of part of the tumor N-myc gene. The clinical implication of this finding is unknown, and additional investigation is warranted.