Diabetes management in cancer patients. An Italian Association of Medical Oncology, Italian Association of Medical Diabetologists, Italian Society of Diabetology, Italian Society of Endocrinology and Italian Society of Pharmacology multidisciplinary consensus position paper.

Cancer management has significantly evolved in recent years, focusing on a multidisciplinary team approach to provide the best possible patient care and address the various comorbidities, toxicities, and complications that may arise during the patient's treatment journey. The co-occurrence of diabetes and cancer presents a significant challenge for health care professionals worldwide. Management of these conditions requires a holistic approach to improve patients' overall health, treatment outcomes, and quality of life, preventing diabetes complications and cancer treatment side-effects. In this article, a multidisciplinary panel of experts from different Italian scientific societies provide a critical overview of the co-management of cancer and diabetes, with an increasing focus on identifying a novel specialty field, 'diabeto-oncology', and suggest new co-management models of cancer patients with diabetes to improve their care. To better support cancer patients with diabetes and ensure high levels of coordinated care between oncologists and diabetologists, 'diabeto-oncology' could represent a new specialized field that combines specific expertise, skills, and training.

MiRNA dysregulation underlying common pathways in type 2 diabetes and cancer development: an Italian Association of Medical Oncology (AIOM)/Italian Association of Medical Diabetologists (AMD)/Italian Society of Diabetology (SID)/Italian Society of Endocrinology (SIE)/Italian Society of Pharmacology (SIF) multidisciplinary critical view.

Increasing evidence suggests that patients with diabetes, particularly type 2 diabetes (T2D), are characterized by an increased risk of developing different types of cancer, so cancer could be proposed as a new T2D-related complication. On the other hand, cancer may also increase the risk of developing new-onset diabetes, mainly caused by anticancer therapies. Hyperinsulinemia, hyperglycemia, and chronic inflammation typical of T2D could represent possible mechanisms involved in cancer development in diabetic patients. MicroRNAs (miRNAs) are a subset of non-coding RNAs, ⁓22 nucleotides in length, which control the post-transcriptional regulation of gene expression through both translational repression and messenger RNA degradation. Of note, miRNAs have multiple target genes and alteration of their expression has been reported in multiple diseases, including T2D and cancer. Accordingly, specific miRNA-regulated pathways are involved in the pathogenesis of both conditions. In this review, a panel of experts from the Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), and Italian Society of Pharmacology (SIF) provide a critical view of the evidence about the involvement of miRNAs in the pathophysiology of both T2D and cancer, trying to identify the shared miRNA signature and pathways able to explain the strong correlation between the two conditions, as well as to envision new common pharmacological approaches.

Antineoplastic dosing in overweight and obese cancer patients: an Associazione Italiana Oncologia Medica (AIOM)/Associazione Medici Diabetologi (AMD)/Società Italiana Endocrinologia (SIE)/Società Italiana Farmacologia (SIF) multidisciplinary consensus position paper.

Most anticancer molecules are administered in body-size-based dosing schedules, bringing up unsolved issues regarding pharmacokinetic data in heavy patients. The worldwide spread of obesity has not been matched by improved methods and strategies for tailored drug dosage in this population. The weight or body surface area (BSA)-based approaches may fail to fully reflect the complexity of the anthropometric features besides obesity in cancer patients suffering from sarcopenia. Likewise, there is a lack of pharmacokinetic data on obese patients for the majority of chemotherapeutic agents as well as for new target drugs and immunotherapy. Therefore, although the available findings point to the role of dose intensity in cancer treatment, and support full weight-based dosing, empirical dose capping often occurs in clinical practice in order to avoid toxicity. Thus a panel of experts of the Associazione Italiana Oncologia Medica (AIOM), Associazione Medici Diabetologi (AMD), Società Italiana Endocrinologia (SIE), and Società Italiana Farmacologia (SIF), provides here a consensus statement for appropriate cytotoxic chemotherapy and new biological cancer drug dosing in obese patients.

Early prediction of pancreatic cancer from new-onset diabetes: an Associazione Italiana Oncologia Medica (AIOM)/Associazione Medici Diabetologi (AMD)/Società Italiana Endocrinologia (SIE)/Società Italiana Farmacologia (SIF) multidisciplinary consensus position paper.

Pancreatic cancer (PC) is a common cause of cancer-related death, due to difficulties in detecting early-stage disease, to its aggressive behaviour, and to poor response to systemic therapy. Therefore, developing strategies for early diagnosis of resectable PC is critical for improving survival. Diabetes mellitus is another major public health problem worldwide. Furthermore, diabetes can represent both a risk factor and a consequence of PC: nowadays, the relationship between these two diseases is considered a high priority for research. New-onset diabetes can be an early manifestation of PC, especially in a thin adult without a family history of diabetes. However, even if targeted screening for patients at higher risk of PC could be a promising approach, this is not recommended in asymptomatic adults with new-onset diabetes, due to the much higher incidence of hyperglycaemia than PC and to the lack of a safe and affordable PC screening test. Prompted by a well-established and productive multidisciplinary cooperation, the Italian Association of Medical Oncology (AIOM), the Italian Medical Diabetologists Association (AMD), the Italian Society of Endocrinology (SIE), and the Italian Society of Pharmacology (SIF) here review available evidence on the mechanisms linking diabetes and PC, addressing the feasibility of screening for early PC in patients with diabetes, and sharing a set of update statements with the aim of providing a state-of-the-art overview and a decision aid tool for daily clinical practice.

Pulsatile antagonism on bradykinin 2-receptor (BK2R) by icatibant triggers the most effective kinin-dependent post-conditioning on rat hearts.

OBJECTIVE: Pharmacological post-conditioning (PC) by intermittent but not continuous administration of exogenous bradykinin (BK) reduces ischemia/reperfusion (I/R) injury via the Reperfusion Injury Salvage Kinase (RISK) pathway activation. We evaluated whether intermittent administration with icatibant (HOE140), a BK2R antagonist, may represent an effective PC strategy, with the advantage of limiting the potential risks of supra-physiologic BK activity. MATERIALS AND METHODS: Hearts from male Sprague-Dawley (SD) rats on a Langendorff system were exposed to I/R injury (30/120 min). BK (100 nM) and HOE140 (1 µM) were administered post-ischemically during the first 3 min of reperfusion, under continuous or intermittent infusion (10 s/each). Hearts were randomly assigned to 5 groups: 1) I/R alone (n=5); 2) continuous HOE140 (cHOE n=6); 3) intermittent HOE140 (iHOE n=6); 4) continuous BK (cBK n=6); 5) intermittent BK (iBK n=6). End-diastolic left ventricular pressure (LVEDP), developed left ventricular pressure (dLVP) and coronary flow (CF) were monitored throughout reperfusion. Left ventricular infarct mass (IM) was quantified together with the phosphorylated levels of Akt and GSK3ß (RISK pathway kinases) at the end of reperfusion. RESULTS: IM was not significantly changed in cBK or cHOE groups (vs. I/R). Conversely, both iBK and iHOE groups showed a significant limitation in IM (vs. I/R, p<0.05, p<0.01, respectively). Akt and GSK3ß phosphorylation levels were higher in iBK and iHOE groups (vs. I/R, p<0.05). When compared to I/R group, both LVEDP values (p<0.05, first 60-min reperfusion), as well as dLVP values (p<0.01) were improved only in iHOE group. CF values did not vary among all groups. CONCLUSIONS: In isolated rat hearts, intermittent modulation of the endogenous kallikrein-kinin system by a selective BK2R antagonist mediates PC cardioprotection via RISK signaling.

Rosiglitazone reverses increased duodenal inhibitory response in spontaneously hypertensive rats.

BACKGROUND: Thiazolidinediones (TZDs) including rosiglitazone (ROSI) are insulin sensitizing agents with beneficial gastrointestinal effects. However, no studies are available on TZDs effect in gastrointestinal motility. We evaluated the effects of ROSI on gastrointestinal inhibitory neurotransmission focusing on the modulatory roles of nitric oxide synthase/nitric oxide (NOS/NO) and heme oxygenase/carbon monoxide (HO/CO) pathways. METHODS: Spontaneously hypertensive rats (SHR) were used as model of insulin resistance. Duodenal strips were obtained from vehicle-treated SHR, ROSI-treated SHR (5 mg kg(-1) by gavage daily per 6 weeks), and Wistar Kyoto (WKY). Inhibitory responses to electrical field stimulation (EFS) were evaluated in the presence of HO inhibitor zinc protoporphyrin IX (ZnPPIX, 10 µmol L(-1)) or NOS inhibitor N(G)-nitro-L-arginine (L-NNA, 100 µmol L(-1)), alone and in combination. Protein levels of HO and NOS isoforms were evaluated by immunohistochemistry and western blot analysis. KEY RESULTS: Basal responses to EFS were significantly increased in duodenum strips from vehicle-treated SHR vs WKY. This effect was reversed in ROSI-treated SHR. The EFS-mediated relaxation was comparably reduced by ZnPPIX in WKY and SHR, but not in ROSI-treated SHR animals. The L-NNA reduced EFS response to a similar extent in WKY and ROSI -treated SHR, but its effect was significantly higher in vehicle-treated SHR. Expression of HO-1 protein was significantly lower, whereas HO-2 protein levels were unchanged in ROSI-treated SHR with respect to vehicle-treated SHR. Finally, increased levels of nNOS in vehicle-treated SHR were reduced in ROSI-treated SHR. CONCLUSIONS & INFERENCES: Chronic ROSI treatment reverses increased SHR duodenal inhibitory response acting on CO and NO components.

Cardiovascular complications in diabetes: lessons from animal models.

Micro- and macro-vascular complications are the leading causes of morbidity and mortality in type 1 and type 2 diabetic patients. Despite the vast clinical experience linking diabetic metabolic abnormalities to cardiovascular lesions, the molecular basis of individual susceptibility to diabetic cardiovascular injury is still largely unknown. Significant advances in this area may come from studies on suitable animal models. Although no animal model can accurately reproduce the human disease, experimental studies in animals have the great advantage to eliminate factors such as ethnicity, economic and geographic variables, drug interactions, diet, gender and age differences that importantly limit clinical studies. Indeed, appropriate animal models have provided important information on genetic and environmental risks of diabetes, and helped to dissect molecular mechanisms underlying the development, progression and therapeutic control of this disease. Unfortunately, none of the diabetic models presently available fully mimics the human syndrome. Therefore, the current knowledge on the pathogenesis of cardiovascular complications relies on the evaluation of distinct phenotypes from various diabetic models. In addition to strains prone to diabetes, this disease can be induced by surgical, pharmacological or genetic manipulation in several animal species. Rodents are the most used, although some studies are still performed in larger animals as rabbits, cats, pigs or monkeys. Far from being exhaustive, this work should serve as a general overview of the most relevant clues provided by major species and models for the overall comprehension of cardiovascular complications in type 1 and type 2 diabetes.

Panic disorder as a risk factor for post-partum depression: Results from the Perinatal Depression-Research & Screening Unit (PND-ReScU) study.

BACKGROUND: Although the role of anxiety disorders on the development of Post-partum Depression (PPD) have already been studied in literature, that of individual anxiety disorders has not received specific attention. The aim of this study is to investigate the role of Panic Disorder (PD) and family history for PD as risk factors for PPD. METHODS: Six hundred women were recruited in a prospective, observational study at the 3rd month of pregnancy and followed up until the 6th month after delivery. At baseline, risk factors for PPD, Axis-I disorders and family history for psychiatric disorders were assessed. We investigated minor and major depression (mMD) occurred at 1st, 3rd and 6th months post-partum. Logistic regression models were used to estimate the association between PD, family history for PD and PPD. RESULTS: Forty women had mMD in the post-partum. PD during pregnancy (RR=4.25; 95%CI:1.48-12.19), a history of PD (RR 2.47; 95%CI:1.11-5.49) and family history for PD (RR=2.1; 95%CI:1.06-4.4) predicted PPD after adjusting for lifetime depression and risk factors for PPD. LIMITATIONS: The response rate is moderately low, but it is similar to other studies. The drop out rate is slightly high, however the 600 women who completed the 6th month follow-up did not differ from the presence of PD at baseline. CONCLUSIONS: PD is an independent risk factor for PPD, underscoring need to assess PD symptoms during pregnancy. Furthermore, PD represents an important risk factor for the development of PPD and should be routinely screened in order to develop specific preventive interventions.

Risk factors for postpartum depression: the role of the Postpartum Depression Predictors Inventory-Revised (PDPI-R). Results from the Perinatal Depression-Research & Screening Unit (PNDReScU) study.

The aims of this study were to identify the frequency of the risk factors for postpartum depression (PPD) listed in the Postpartum Depression Predictors Inventory-Revised (PDPI-R) during pregnancy and 1 month after delivery and to determine the predictive validity of the PDPI-R. The study used a prospective cohort design. Women completed the PDPI-R at the 3rd and the 8th months of pregnancy and at the 1st month after childbirth. Women were prospectively followed across three different time points during the postpartum using Structured Clinical Interview for DSM-IV Disorders to determine the presence of major or minor depression. The prenatal version of the PDPI-R administered at two different time points during pregnancy predicted accurately 72.6% and 78.2% of PPD and the full version administered at the 1st month after delivery predicted 83.4% of PPD. The cutoffs identified were 3.5 for the prenatal version and 5.5 for the full version. The PDPI-R is a useful and a valid screening tool for PPD.

Generation of a novel antibody probe to the apical sodium-dependent bile acid transporter that inhibits ileal bile acid absorption.

Intestinal bile acid absorption is mediated by a sodium-dependent transporter located in the brush border apical membrane of ileocytes. The transmembrane topology and the role of individual amino acid residues in the bile acid transport process have been investigated by means of various experimental approaches, leading to multiple hypotheses. We raised a monoclonal antibody against a segment of the transporter comprising vicinal cysteine residues, in order to evaluate its functional role. A 14 amino acid peptide, corresponding to amino acids 104-117 of the transporter, was synthesized, and a monoclonal anti-peptide antibody was raised. In vitro uptake-inhibition studies in the presence of the monoclonal anti-peptide antibody were performed using ileal brush border membrane vesicles. Rabbit ileum was perfused in vivo with 5 mM taurocholic acid in the presence of the monoclonal antibody, and bile acid absorption inhibition was evaluated. The anti-peptide monoclonal antibody significantly reduced the in vitro uptake and in vivo absorption of taurocholic acid. The present data demonstrate the functional relevance of the 104-117 peptide segment and report the generation of a novel antibody against the apical sodium-dependent bile acid transporter (ASBT) that may be used as a therapeutic agent in hypercholesterolemia and in cholestatic pruritus.

Diabetic cardiomyopathy: how much does it depend on AGE?

Diabetic cardiomyopathy refers to dysfunction of cardiac muscle in patients with diabetes that cannot be directly ascribed to hypertension, coronary heart disease or other defined cardiac abnormalities per se. The development of diabetic cardiomyopathy may involve several distinct mechanisms, including increased formation of advanced glycation end products (AGEs) secondary to hyperglycaemia. AGEs may alter structural proteins and lead to increased arterial and myocardial stiffness. Therefore, therapies that prevent or retard development of AGEs in diabetes may be valuable strategies to treat or prevent diabetic cardiomyopathy. In this issue of British Journal of Pharmacology, Wu and colleagues demonstrate that aminoguanidine (inhibitor of AGE formation and protein cross-linking) treatment of a rat model of type I diabetes (rats made insulin deficient with streptozotocin and nicotinamide treatment) ameliorates detrimental changes in left ventricular structure and function. Results from this study are in agreement with previous investigations, suggesting that aminoguanidine is effective in preventing cardiac hypertrophy and arterial stiffening in experimental animal models of diabetes and emphasize the potential pathogenic role of AGEs in diabetic cardiomyopathy.

Hepatobiliary phospholipid transporter ABCB4, MDR3 gene variants in a large cohort of Italian women with intrahepatic cholestasis of pregnancy.

BACKGROUND: Intrahepatic cholestasis of pregnancy is a multifactorial disorder of pregnancy associated with a genetic background. AIM: To evaluate the genetic contribution of ABCB4, MDR3 gene in the development of intrahepatic cholestasis of pregnancy in a large cohort of Italian subjects. METHODS: This study represents an extension of a previous multicentre-prospective study including three Italian referral centres. In all, we enrolled 96 women at the 3rd trimester of pregnancy. Genomic DNA was extracted from peripheral venous blood leucocytes by standard procedures. Polymerase chain reaction was used to amplify exon 14, 15 and 16 of MDR3 gene. RESULTS: We found 3 non-synonymous heterozygous mutations in exon 14 (E528D, R549H, G536A), 1 in exon 15 (R590Q) and 2 in exon 16 (R652G, T6671). MDR3 gene variants in exons 14, 15 and 16 occurred in 7/96 of pregnant mothers with intrahepatic cholestasis of pregnancy (7.2%), and in none of 96 pregnant controls matched for age and parity. All seven patients had normal gamma-glutamyl transpeptidase, normal bilirubin, but high levels of both alanine transferase and serum bile acids. One had cholesterol biliary lithiasis. The outcome of pregnancy was normal in four cases (with vaginal delivery), while there was one fetal distress. CONCLUSIONS: MDR3 mutations are responsible for the development of intrahepatic cholestasis of pregnancy in only a small percentage of Italian women. Further genetic studies are warranted, however, to clarify the role of different mutations in intrahepatic cholestasis of pregnancy.

Transjugular intrahepatic portosystemic shunt: a case report of rescue management of unrestrainable variceal bleeding in a pregnant woman.

Liver cirrhosis complications in pregnant women are frequent and death rate secondary to variceal bleeding is relevant. Both sclerotherapy and banding ligation seem to be safe procedures in pregnancy; when bleeding is not arrested endoscopically an emergency transjugular intrahepatic portosystemic shunt should be considered, but data regarding pregnant cirrhotic women are scarce. We describe the case of a pregnant woman at 14 weeks of gestation who underwent management of acute variceal bleeding by transjugular intrahepatic portosystemic shunt. Transjugular intrahepatic portosystemic shunt may represent a rescue treatment for failed attempts of band ligation or sclerotherapy.

Neurofunctional effects of developmental sodium fluoride exposure in rats.

Contrasting studies on the toxic effects of sodium fluoride (NaF) during developmental stages of Wistar rats, lead us to investigate the neurofunctional effects caused by its perinatal exposure, devoid of any overt sign of toxicity and/or gross malformation. NaF solution was administered to pregnant rats by intragastric gavage at a daily dose of 2.5 and 5.0 mg/kg from gestational day 0 to day 9 after parturition. Developmental NaF exposure caused sex and dose specific behavioural deficits which affected males more than females in the majority of the evaluated end-points. In particular, the perinatal exposure to NaF 5.0 mg/kg, significantly affected learning, memory, motor coordination and blood pressure only in male rats. Conversely, a lack of habituation upon the second presentation of the objects and failure in the ability to discriminate between the novel and the familiar object were observed only in NaF 5.0 mg/kg female rats. Finally, a significant impairment of sexual behaviour was observed in male rats at both NaF dose levels. The present data indicate that perinatal rat exposure to NaF results in long lasting functional sex-specific alterations which occur at fluoride levels approaching those experienced by offspring of mothers.

Clinical trial: modulation of human placental multidrug resistance proteins in cholestasis of pregnancy by ursodeoxycholic acid.

BACKGROUND: The effects of ursodeoxycholic acid on human placental bile acids and bilirubin transporters in intrahepatic cholestasis of pregnancy are still undefined. AIM: To evaluate whether ursodeoxycholic acid affects MRP2, MRP3 and MRP4 expression in the placenta. MATERIALS AND METHODS: Forty-three pregnant women were enrolled; fourteen subjects had physiological pregnancies. Intrahepatic cholestasis of pregnancy patients were divided into two groups: (i) 13 received ursodeoxycholic acid (20 mg/kg/day) and (ii) 16 untreated. Total bile acid and bilirubin in serum and cord blood were determined in each subject. Multidrug resistance proteins expression (immunoblot, quantitative real-time PCR) was evaluated in placentas collected at delivery. anova test was used for statistical analysis of data. RESULTS: Ursodeoxycholic acid administration significantly improved maternal serum bile acid and cord blood bilirubin and bile acid levels. MRP2 protein and RNA expression was significantly increased in placentas from treated patients compared to controls (P < 0.001 and P < 0.01, respectively). MRP3 protein expression was not significantly different between the groups while RNA expression was significantly decreased in treated patients (P < 0.01). MRP4 did not show significant differences between the groups. CONCLUSIONS: Ursodeoxycholic acid administration induces placental MRP2 expression, and reduces bilirubin and bile acid levels in cord blood.

Photorefractive keratectomy in high myopic defects with or without intraoperative mitomycin C: 1-year results.

PURPOSE: To study the results of the prophylactic use of mitomycin C (MMC) to reduce haze formation and refractive regression after excimer laser photorefractive keratectomy (PRK) for high myopic defects (>5 diopters). METHODS: Prospective, consecutive, observational study. A total of 124 eyes of 62 patients were divided into two groups of 31 patients, 62 eyes each (Groups A and B). Only Group A was treated with MMC 0.02%. The data of the two groups of eyes, related to the best-corrected visual acuity (BCVA), to the difference of refraction pre- and post-treatment, and to the corneal haze, were analyzed through combined permutation tests by using the NPC Test software . RESULTS: BCVA of Group A, 1 year after treatment, was better than that of the control Group B (one-sided p value = 0.013): Group A - 3 eyes (4.8%) had a loss of a decimal fraction and no eyes > 1; Group B - 13 eyes (20.9%) had a loss of a decimal fraction and 1 eye (1.6%) of 2. There was a smaller difference between attempted and achieved SE correction in Group A with respect to Group B (one-sided p value = 0.068): Group A - 43 eyes (69.3%) within +/- 0.50 D; Group B - 31 eyes (50%) within +/- 0.50 D. there was a smaller incidence of corneal haze in the group for which MMC was used (one-sided p value = 0.005). CONCLUSIONS: In this study, the application of MMC 0.02% solution immediately after PRK produced lower haze rates and had better predictability and improved efficacy 1 year after treatment.

Higher doses of peginterferon alpha-2b administered twice weekly improve sustained virological response in difficult-to-treat patients with chronic hepatitis C: results of a pilot randomized study.

SUMMARY: Beside substantial progress in treatment of chronic hepatitis C (CHC) particular patients (genotype 1/4, high viral load, previous nonresponse, cirrhosis) remain difficult to treat. The aim of our pilot randomized study was to compare efficacy and tolerability of standard doses of Peginterferon alpha-2b + ribavirin with higher doses of Peginterferon alpha-2b administered twice weekly + ribavirin. Sixty-five outpatients with CHC were subsequently enrolled. Group A (n = 22) received recommended doses of Peginterferon alpha-2b and group B (n = 43), received high doses twice weekly. Groups were comparable for baseline characteristics. All genotype 1/4 patients had high baseline viraemia. Sustained virological response (SVR) was significantly higher in group B among naïve patients (72%vs 25%, P = 0.024). A significantly higher rate of SVR was observed in group B both considering only genotype 1/4 patients, (46%vs 13%, P = 0.03) and grouping together genotype 1/4 naive and relapsers (57%vs 11%, P = 0.039). Discontinuation rate was 32% (7 of 22) in group A and 21% (9 [corrected] of 43) in group B. Our response rates are the highest reported for genotype 1/4 with high viraemia. Our pilot study supports the need of randomized studies to evaluate both viral kinetics and efficacy of high dose and twice weekly administration of Peginterferon alpha-2b in genotype 1/4 patients with high viraemia who may need personalized treatment schedules.

[Cholic acid metabolism in human fecal cultures during diet supplementation with Lacto-bacillus rhamnosus GG]. / Metabolismo dell'acido colico in colture di feci umane in corso di assunzione di una dieta con aggiunta di Lactobacillus rhamnosus GG. Dati preliminari.

BACKGROUND: Lactobacillus rhamnosus GG is used as probiotic and is thought to have protective properties in the human gastrointestinal tract and in other organs. Enrichment of the bile acid pool with secondary bile acids is common in some hepatic and gastrointestinal diseases and this is considered as a pathogenic element in the disease progression. The aim of this study was to evaluate the effect of probiotic feeding on fecal bile acid biotransformation, particularly on the production of secondary bile acids. METHODS: Six normal volunteers were administered 500 g/die of a yogurt preparation containing 4 x 10(9) C.F.U. of Lactobacillus rhamnosus GG for 30 days. The 7alpha-dehydroxylation activity was investigated following addition of cholic acid to the stool samples collected before and after the probiotic feeding. The production of deoxycholic acid and the decrease in cholic acid level were studied. RESULTS: The comparison of biotransformation rate of cholic acid to deoxycholic acid before and after probiotic feeding didn't reach a statistically significant difference, but a strong difference was seen in three of the six subjects, indicating a different behavior in different groups of healthy subjects. Furthermore, the three non responder subjects had a lower fecal 7alpha-dehydroxylation activity in the stool samples from the pre-treatment collection. CONCLUSIONS: These results indicate that subjects with a higher production of secondary bile acids in stools may represent a target group for a larger trial with oral probiotic administration.

Absence of dysfunctional ileal sodium-bile acid cotransporter gene mutations in patients with adult-onset idiopathic bile acid malabsorption.

BACKGROUND: A congenital form of idiopathic intestinal bile acid malabsorption (IBAM) has been associated with dysfunctional mutations in the ileal apical sodium-dependent bile acid transporter (ASBT). The aim of this study was to determine whether mutations in the ASBT gene (SLC10A2) predispose to the development of adult-onset idiopathic bile acid malabsorption and chronic watery diarrhea. METHODS: Genomic DNA was obtained from 13 adult IBAM patients previously diagnosed on the basis of clinical data, response to cholestyramine, and abnormal 75Se-homocholic acid taurine (SeHCAT) test values. The ASBT gene was screened for the presence of mutations or polymorphisms by single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing. RESULTS: ASBT gene polymorphisms were detected in 5 of the 13 adult IBAM patients. Four patients were heterozygous for a common polymorphism in exon 3, leading to an alanine to serine substitution at codon 171 (A171S). An additional subject was heterozygous for a polymorphism in exon 1 that causes a valine to isoleucine substitution at codon 98 (V981). These functional polymorphisms were also found in unaffected subjects and do not appear to affect ASBT function. CONCLUSIONS: Adult-onset IBAM is not directly related to dysfunctional mutations in the coding region or intron/exon junctions of the SLC10A2 gene. In the absence of apparent ileal disease or intestinal motility defects, inappropriate down-regulation of the ileal bile acid transporter or defects in ileocyte transfer of bile acids into the portal circulation could explain this form of adult IBAM.

Insulin-stimulated activation of eNOS is independent of Ca2+ but requires phosphorylation by Akt at Ser(1179).

Vasodilator actions of insulin are mediated by activation of endothelial nitric-oxide synthase (eNOS) and subsequent production of NO. Phosphatidylinositol 3-kinase and Akt play important roles in insulin-signaling pathways leading to production of NO in vascular endothelium. Here we dissected mechanisms whereby insulin activates eNOS by using the fluorescent dye DAF-2 to directly measure NO production in single cells. Insulin caused a rapid increase in intracellular NO in NIH-3T3(IR) cells transiently transfected with eNOS. The stimulation of NO production by lysophosphatidic acid (LPA) was abrogated by pretreatment of cells with the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Remarkably, in the same cells, insulin-stimulated production of NO was unaffected. However, cells expressing the eNOS-S1179A mutant (disrupted Akt phosphorylation site) did not produce detectable NO in response to insulin, whereas the response to LPA was similar to that observed in cells expressing wild-type eNOS. Moreover, production of NO in response to insulin was blocked by coexpression of an inhibitory mutant of Akt, whereas the response to LPA was unaffected. Phosphorylation of eNOS at Ser(1179) was observed only in response to treatment with insulin, but not with LPA. Interestingly, platelet-derived growth factor treatment of cells activated Akt but not eNOS. Results from human vascular endothelial cells were qualitatively similar to those obtained in transfected NIH-3T3(IR) cells, although the magnitude of the responses was smaller. We conclude that insulin regulates eNOS activity using a Ca(2+)-independent mechanism requiring phosphorylation of eNOS by Akt. Importantly, phosphorylation-dependent mechanisms that enhance eNOS activity can operate independently from Ca(2+)-dependent mechanisms.