Obestatin enhances in vitro generation of pancreatic islets through regulation of developmental pathways

Availability of large amounts of in vitro generated β-cells may support replacement therapy in diabetes. However, methods to obtain β-cells from stem/progenitor cells are limited by inefficient endocrine differentiation. We have recently shown that the ghrelin gene product obestatin displays beneficial effects on pancreatic β-cell survival and function. Obestatin prevents β-cell apoptosis, preserves β-cell mass and stimulates insulin secretion in vitro and in vivo, in both normal and diabetic conditions. In the present study, we investigated whether obestatin may promote in vitro β-cell generation from mouse pancreatic islet-derived precursor cells. Treatment of cultured islets of Langerhans with obestatin (i) enriched cells expressing the mesenchymal/neuronal marker nestin, which is associated with pancreatic precursors; (ii) increased cell survival and reduced apoptosis during precursor selection; (iii) promoted the generation of islet-like cell clusters (ICCs) with increased insulin gene expression and C-peptide secretion. Furthermore, obestatin modulated the expression of fibroblast growth factor receptors (FGFRs), Notch receptors and neurogenin 3 (Ngn3) during islet-derived precursor cell selection and endocrine differentiation. These results indicate that obestatin improves the generation of functional β-cells/ICCs in vitro, suggesting implications for cell-based replacement therapy in diabetes. Moreover, obestatin may play a role in regulating pathways involved in pancreas development and regeneration.

Immunohistochemical Profile and VEGF, TGF-β and PGE2 in Human Pterygium and Normal Conjunctiva: Experimental Study and Review of the Literature

Human pterygium is made up of chronic proliferative fibro-vascular tissue growing on the ocular surface. This disease exhibits both degenerative and hyperplastic properties. Some fibroangiogenic factors have recently been shown to play a potential role in fibrovascular diseases via the angiogenesis process. The aim of this study is to evaluate VEGF, TGF-β and PGE2 expression in the epithelial, endothelial and stromal cells of human pterygium and normal conjunctiva in order to determine whether these factors participate in the development of pterygium. Ten specimens from patients with pterygium and two normal conjunctivas (cadavers) were analyzed by immunohistochemistry using specific antibodies against these growth factors. The technique used was ABC/HRP (Avidin complexed with biotinylated peroxidase). Immunoreactivity of VEGF was significantly increased in the epithelium, vascular endothelium and stromal cells in primary pterygium as compared with normal conjunctiva. A moderate expression of TGF-β in the pterygium was observed in the epithelial and stromal layers. On the contrary, immunolabeling of this growth factor in the human normal conjunctiva was weak. PGE2 was strongly expressed in the epithelium of patients with pterygium, as in control conjunctival tissues, and the immunolabeling was moderate in the stroma from the same patients. Our results suggest that these growth factors may contribute to the progression of primary pterygium by increasing angiogenesis, thus leading to the formation of new blood vessels from the pre-existing vasculature. We conclude that VEGF, TGF-β and PGE2 may be potential therapeutic targets in the treatment of this disease although proof of this evidence requires further studies.

Obestatin regulates adipocyte function and protects against diet-induced insulin resistance and inflammation

The metabolic actions of the ghrelin gene-derived peptide obestatin are still unclear. We investigated obestatin effects in vitro, on adipocyte function, and in vivo, on insulin resistance and inflammation in mice fed a high-fat diet (HFD). Obestatin effects on apoptosis, differentiation, lipolysis, and glucose uptake were determined in vitro in mouse 3T3-L1 and in human subcutaneous (hSC) and omental (hOM) adipocytes. In vivo, the influence of obestatin on glucose metabolism was assessed in mice fed an HFD for 8 wk. 3T3-L1, hSC, and hOM preadipocytes and adipocytes secreted obestatin and showed specific binding for the hormone. Obestatin prevented apoptosis in 3T3-L1 preadipocytes by increasing phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2 signaling. In both mice and human adipocytes, obestatin inhibited isoproterenol-induced lipolysis, promoted AMP-activated protein kinase phosphorylation, induced adiponectin, and reduced leptin secretion. Obestatin also enhanced glucose uptake in either the absence or presence of insulin, promoted GLUT4 translocation, and increased Akt phosphorylation and sirtuin 1 (SIRT1) protein expression. Inhibition of SIRT1 by small interfering RNA reduced obestatin-induced glucose uptake. In HFD-fed mice, obestatin reduced insulin resistance, increased insulin secretion from pancreatic islets, and reduced adipocyte apoptosis and inflammation in metabolic tissues. These results provide evidence of a novel role for obestatin in adipocyte function and glucose metabolism and suggest potential therapeutic perspectives in insulin resistance and metabolic dysfunctions.

Somatostatin and somatostatin analogues reduce PDGF-induced endometrial cell proliferation and motility

BACKGROUND

Endometriosis is characterized by ectopic implantation of endometrial cells, which show increased proliferation and migration. Somatostatin (SST) and its analogues inhibit normal and cancer cell growth and motility through the SST receptors, sst1-5. Cortistatin (CST), which displays high structural and functional homology with SST, binds all ssts, as well as MrgX2. Our objective was to investigate the gene expression of the SST/CST system and to determine the effect of SST and its analogues on platelet-derived growth factor (PDGF)-induced proliferation and motility in telomerase-immortalized human endometrial stromal cell (T HESC) line and in primary endometrial stromal cell (ESCs) isolated from human endometriotic tissues.

METHODS

Ectopic endometrial tissues were collected from women (n= 23) undergoing laparoscopic surgery for endometriosis (Stage III/IV). Gene expression was evaluated by real-time PCR, cell motility by wound healing assay, protein expression and β-actin rearrangement by immunofluorescence, cell proliferation by the Alamar blue assay and ERK1/2 and Akt phosphorylation by western blot.

RESULTS

Human endometriotic tissues, primary ESCs and T HESCs expressed SST, CST and ssts. SST, its analogues SOM230 and octreotide, as well as CST, counteracted PDGF-induced proliferation and migration in both ESCs and T HESCs. SST also inhibited vascular endothelial growth factor and metalloprotease-2 mRNA expression, and reduced basal and PDGF-induced ERK1/2 phosphorylation.

CONCLUSION

These results indicate that the SST/CST system is expressed in endometriotic tissues and cells. The inhibitory effects of SST and its analogues on PDGF-induced proliferation and motility suggest that these peptides may represent promising tools in the treatment of endometriosis.

[Gastroschisis. Preterm elective cesarean and immediate primary closure: our experience]

PURPOSE

Our experience en treatment of gastroschisis using a protocol with elective preterm delivery by caesarean section at 34-35 weeks and immediate primary abdominal wall closure.

METHODS

During a period of 18 month we treated 5 patients with gastroschisis using the following management pathway: Starting at 30th week of gestation, weekly ultrasound evaluation of fetal gut and pulmonary maturation with corticosteroids. Delivery by elective caesarean section between 34-35 weeks or earlier if evidence of bowel compromise was reported en ultrasound study. Immediate surgical correction after birth with primary closure was preformed under control of abdominal pressure.

RESULTS

Mean gestational age of our patient was 33,94 weeks, and mean birth weight was 2154 gr. None of the cases present inflammatory peel and we found no difficulties for reduction of the gut at time of surgery. Two patients presented an intestinal malrotation. Extubation was preformed 36-48 hours after surgery. We started a trofic diet at 3,6 days and parental nutrition was retired after a mean period of 15,8 days. The mean time of hospital stay was 33,4 days. One patient with intestinal obstruction had a consideriously increased length of hospital stay of 74 days.

CONCLUSIONS

A management pathway for gastroschisis with selective preterm delivery by caesarean section and immediate surgical treatment probably reduces the experience of inflammatory peel. This pathway permits a early initiation of oral feeding, reduces times of parenteral nutrition and need of central catheters, and shortens length of hospital stay.

A retrospective observational study on the safety and efficacy of first-line treatment with bevacizumab combined with FOLFIRI in metastatic colorectal cancer

BACKGROUND

Combination of bevacizumab and FOLFIRI has currently become one of the standard therapeutic regimens. However, published information is still limited. The objective of the present retrospective observational study is to analyse the response and toxicity of first-line treatment with FOLFIRI+bevacizumab in patients with metastatic colorectal cancer (mCRC).

METHODS

Data were collected from patients from nine Spanish sites diagnosed with mCRC, ECOG≤2, whose first treatment for advanced disease was at least three cycles of FOLFIRI+bevacizumab.

RESULTS

A total of 95 patients were enrolled into the study: 64.2% males, median age of 59 years (53.2-67.1 years), ECOG=0-1 in 96.9% of patients. The main site of primary tumour was the colon (69.7%), and most metastases occurred in the liver (71.6%). Clinical benefit was detected in 67.4% (57.0-76.6; 95% confidence interval (CI)), with 8.4% of CR and 42.1% of PR. Median TTP was 10.6 months (10.0-11.3; 95% CI), PFS was 10.6 months (9.8-11.3; 95% CI), and OS was 20.7 months (17.1-24.2; 95% CI). Main grade I-II toxicities included haematological toxicity (35.8%), diarrhea (27.3%), mucositis (25.3%), asthenia (19.0%), haemorrhages (11.6%), and emesis (10.6%). Toxicities reaching grades III-IV were haematological toxicity (9.5%), diarrhea (8.5%), mucositis (5.3%), hepatic toxicity (2.1%), asthenia (2.1%), proteinuria (1.1%), emesis (1.1%), pain (1.1%), and colics (1.1%).

CONCLUSION

Results of this study support the beneficial effect of adding bevacizumab to FOLFIRI regimen in terms of efficacy and show a favourable tolerability profile.

Acute responses of gastrointestinal hormones to both oral and parenteral intradialytic nutrition

INTRODUCTION

Intradialytic nutrition (IDN) has been used to improve the nutritional status of malnourished hemodialysis (HD) patients.

OBJECTIVE

To evaluate the different effects of parenteral IDN (IDPN) and oral IDN (IDON) on nutrition-related gastrointestinal hormones.

PATIENTS AND METHODS

Seven clinically stable HD patients with malnutrition were included. All patients were treated for 1 month with either IDPN or IDON, with a 4-week period of no nutritional support between each type of therapy. On the first day of each nutritional support (IDON or IDPN) we analyzed the acute responses of insulin, ghrelin, and glucagon-like peptide 1 (GLP-1). We compared the areas under the secretory curves (AUC) and the maximum peaks of serum glucose, insulin, ghrelin, and GLP-1. A group of 6 clinically stable HD patients without any type of IDN served as the control group.

RESULTS

The acute responses of glucose and insulin to IDN were significantly higher with IDPN than with IDON. The AUC of glucose (602 ± 81 vs. 495 ± 81 mg/dl/h, p < 0.01) and insulin (232 ± 103 vs. 73.8 ± 69 μU/ml/h, p < 0.01) as well as the maximum peaks of glucose (228 ± 41 vs. 177 ± 47 mg/dl, p < 0.05) and insulin (104 ± 46 vs. 29 ± 24 μU/ml, p < 0.01) were significantly higher after IDPN than after IDON. Ghrelin decreased after both IDPN and IDON; however, the decrease was significantly higher with IDPN compared to IDON. The ghrelin nadir was significantly lower in IDPN than in IDON (0.77 ± 0.5 vs. 1.5 ± 0.3, p < 0.05) although the AUC of ghrelin was not significantly different. GLP-1 was significantly increased at 1 h after starting both IDPN and IDON with no significant differences between the groups.

CONCLUSION

IDPN induces a higher increase in serum glucose and insulin levels and a greater reduction in serum ghrelin concentrations compared with an equivalent orally administered nutritional supplement.

Lophotrochozoa get into the game: the nodal pathway and left/right asymmetry in bilateria

Animals as diverse as humans, flies, crabs, and snails show overall bilateral symmetry, but each species has specific structures and organs that display left/right asymmetry, and the presence of these asymmetries is vital to the organism. Here, we review recent results showing that part of the molecular pathway that sets left/right asymmetry in vertebrates is also conserved in snails, suggesting that left/right asymmetry was present in the common ancestor of all bilaterians. More specifically, we can now predict that the signaling molecule Nodal and the transcription factor Pitx were expressed on the right side of the bilaterian ancestor. These results also allow us to understand how the direction of shell coiling (chirality) is regulated in snails and provides interesting insights into the possible inversion of the dorsoventral axis in the lineage leading to chordates.

Human gallbladder carcinoma: Role of neurotrophins, MIB-1, CD34 and CA15-3

Gallbladder carcinoma is the most common biliary tract tumor and the fifth most common gastrointestinal tract cancer. The prognosis of gallbladder carcinoma is poor and less than 5% of the patients are still alive five years postoperatively. Gallbladder specimens were obtained during surgical operations performed in eleven patients for resection of a gallbladder carcinoma, and during five autopsies (control cases selected among patients who died from for other causes, excluding those suffering from biliary or hepatic diseases). Immunohistochemical characterization and distribution of neurotrophins, with their respective receptors, were analyzed. The actual role played by these neurotrophic factors in the general regulation, vascular permeability, algic responsiveness, release of locally active substances and potential tumorigenesis in the gallbladder and biliary ducts compartment remains controversial. Our study revealed an increased immunohistochemical expression of NGF and TrKA in the epithelium and in the epithelial glands of the gallbladder carcinoma together with an evident immunoreactivity for BDNF in the same neoplastic areas. An evident immunoreactivity for NGF, TrKA and BDNF was observed in control specimens of gallbladder obtained during autopsies, whereas a weak or quite absent immunoreactivity was observed in the same specimens for NT4, TrKC and p75. On the contrary an appreciable immunoreactivity for p75 was observed in the specimens harvested from patients with gallbladder carcinoma. We also investigated the expression of some known tumor markers such as MIB-1 (anti Ki-67), CD34 and CA15-3, to identify a possible correlation between the expression of these molecular factors and the prognosis of gallbladder carcinoma. They resulted highly expressed in the stroma (CD34 and CA 15-3) and in the epithelium/epithelial glands (MIB-1) of the neoplastic areas and appeared to be almost absent in the control cases, suggesting that these markers, taken together, could be adopted as a panel of prognostic factors in the evaluation of the gallbladder carcinoma.

Neogastropod phylogenetic relationships based on entire mitochondrial genomes

Background

The Neogastropoda is a highly diversified group of predatory marine snails (Gastropoda: Caenogastropoda). Traditionally, its monophyly has been widely accepted based on several morphological synapomorphies mostly related with the digestive system. However, recent molecular phylogenetic studies challenged the monophyly of Neogastropoda due to the inclusion of representatives of other caenogastropod lineages (e.g. Littorinimorpha) within the group. Neogastropoda has been classified into up to six superfamilies including Buccinoidea, Muricoidea, Olivoidea, Pseudolivoidea, Conoidea, and Cancellarioidea. Phylogenetic relationships among neogastropod superfamilies remain unresolved.

Results

The complete mitochondrial (mt) genomes of seven Neogastropoda (Bolinus brandaris, Cancellaria cancellata, Conus borgesi, Cymbium olla, Fusiturris similis, Nassarius reticulatus, and Terebra dimidiata) and of the tonnoidean Cymatium parthenopeum (Littorinimorpha), a putative sister group to Neogastropoda, were sequenced. In addition, the partial sequence of the mitochondrial genome of the calyptraeoidean Calyptraea chinensis (Littorinimorpha) was also determined. All sequenced neogastropod mt genomes shared a highly conserved gene order with only two instances of tRNA gene translocation. Phylogenetic relationships of Neogastropoda were inferred based on the 13 mt protein coding genes (both at the amino acid and nucleotide level) of all available caenogastropod mitochondrial genomes. Maximum likelihood (ML) and Bayesian inference (BI) phylogenetic analyses failed to recover the monophyly of Neogastropoda due to the inclusion of the tonnoidean Cymatium parthenopeum within the group. At the superfamily level, all phylogenetic analyses questioned the taxonomic validity of Muricoidea, whereas the monophyly of Conoidea was supported by most phylogenetic analyses, albeit weakly. All analyzed families were recovered as monophyletic except Turridae due to the inclusion of Terebridae. Further phylogenetic analyses based on either a four mt gene data set including two additional Littorinimorpha or combining mt and nuclear sequence data also rejected the monophyly of Neogastropoda but rendered rather unresolved topologies. The phylogenetic performance of each mt gene was evaluated under ML. The total number of resolved internal branches of the reference (whole-mt genome) topology was not recovered in any of the individual gene phylogenetic analysis. The cox2 gene recovered the highest number of congruent internal branches with the reference topology, whereas the combined tRNA genes, cox1, and atp8 showed the lowest phylogenetic performance.

Conclusion

Phylogenetic analyses based on complete mt genome data resolved a higher number of internal branches of the caenogastropod tree than individual mt genes. All performed phylogenetic analyses agreed in rejecting the monophyly of the Neogastropoda due to the inclusion of Littorinimorpha lineages within the group. This result challenges morphological evidence, and prompts for further re-evaluation of neogastropod morphological synapomorphies. The important increase in number of analyzed positions with respect to previous studies was not enough to achieve conclusive results regarding phylogenetic relationships within Neogastropoda. In this regard, sequencing of complete mtDNAs from all closely related caenogastropod lineages is needed. Nevertheless, the rapid radiation at the origin of Neogastropoda may not allow full resolution of this phylogeny based only on mt data, and in parallel more nuclear sequence data will also need to be incorporated into the phylogenetic analyses.

High stable serum adiponectin levels are associated with a better outcome in prevalent dialysis patients

AIMS

Our aim was to evaluate the prognostic value of 2 measurements of serum adiponectin levels for all-cause mortality and cardiovascular (CV) mortality in uremic patients.

METHODS

We analyzed 184 patients (19-86 years) undergoing peritoneal dialysis (n = 86) or hemodialysis (n = 98). All patients had 2 measurements of serum adiponectin levels (at baseline and after 1 year). Relationships between adiponectin and mortality were studied by means of survival analysis and Cox regression analysis.

RESULTS

During a median follow-up time of 31.2 months, 67 patients (36.4%) died, 26 (14.1%) as a result of CV disease. Mean survival time for CV mortality in patients with 1-year adiponectin values in the upper tertile was significantly higher than that found in patients in the middle and lower tertiles. Hazard ratios (HR) for all-cause mortality per SD change were 0.70 (95% CI, 0.50-0.98; p < 0.05) for baseline adiponectin levels and 0.68 (0.49-0.95; p < 0.05) for mean baseline and 1-year adiponectin levels. Mean adiponectin levels were also negatively related with CV mortality [HR 0.43 (0.21-0.86); p < 0.05] and CV events [HR 0.74 (0.55-0.99); p < 0.05].

CONCLUSIONS

In this population of dialysis patients, adiponectin seems to behave as a CV protective factor. Patients with high mean adiponectin levels had a better survival rate.

Phase II study of biweekly XELOX (capecitabine and oxaliplatin) as first line chemotherapy in elderly patients with metastatic colorectal cancer

e15053

Background: Analysis of efficacy and toxicity of biweekly XELOX as first line monotherapy in elderly patients (pts) with metastatic colorectal cancer (MCRC), based in results of W. Scheithauer (J Clin Oncol 2003; 21: 1307). Methods: From March/06 to November/08, 28 chemonaïve elderly pts (>75 years old) with MCRC, PS: 0–2, and adequate renal, hepatic and bone marrow functions, were included in a phase II study of: oxaliplatin 85 mg/ m2/ day 1 plus capecitabine 2000/ m2/ in 2 divided doses/ days 1–7 every 2 weeks. Treatment was continued until 12 cycles, tumour progression or innaceptable toxicity. Response evaluation every 6 cycles and toxicity every cycle was performed. At present 28 pts for toxicity and 24 pts for response are evaluable. Results: Median age: 78.2 years (range: 73.5–79.5). Male/Female: 14/14. Rectal/Colon: 9/19. Metastatic sites 1/2/>2: 15/6/6. Liver 78.6%, Lung 32.1%, Local tumour 7.1%, Retroperitoneum 14.2%, Peritoneum 10.7%. and Bones 7.1 %. Previous adjuvant with 5-FU regimens to 4 pts. Comorbidity grade by Charlson index 0–1/2/>2: 60.8%/ 28.6% / 10.7%, respectively. Median number of cycles for oxaliplatin and capecitabine were 8 (5.25–12) and 8 (5.25–11.75). Response rate: 2 pts complete response (8.3%), 8 pts partial response (33.3%),10 pts stable disease (41.7 %) and 4 pts progression (16.7%). The main CTC toxicity was Asthenia G2+3 in 6 (21.5%), Nausea and emesis G2 in 7 (25%), Diarrhea G2+3 in 7 (25%) and Hand-foot syndrome G1+2 in 5 pts (17.8%). No G4 toxicity or toxic deaths were observed. Median time to progression was 8.6 months.Median overall survival will be given updated at the congress. Conclusions: Preliminary results suggest that bi-weekly XELOX is an effective first line treatment for MCRC in elderly pts with an acceptable toxicity profile (especial surveillance of diarrhea is necessary) and protocol cumpliment. Combination with bevacizumab should be considered.

No significant financial relationships to disclose.

[Primary hepatic lymphoma - favorable outcome with chemotherapy plus rituximab]

This article describes the case of a patient with a non-Hodgkin primary hepatic lymphoma who was successfully treated with chemotherapy combined with rituximab. Using the Medical Subject Headings the published reports of this rare entity were reviewed.