INTRA-DUODENAL RELEASE OF A BITTER COMPOUND DECREASES CALORIC INTAKE IN HEALTHY VOLUNTEERS

Background and aim: α-gustducin and bitter taste receptors (T2R) are expressed both in the oral cavity and in the gastrointestinal (GI) tract. Experimental data showed that bitter tastants induce the release of gut hormones from enteroendocrine cells in the gut, suggesting a possible role of bitter taste receptors in the control of food intake and GI functions. We aimed to test the effects of a bitter taste receptor agonist on food intake and GI feelings. Material and methods: We enrolled 19 healthy subjects (9 males, age 27±7, BMI 24±6) in a double-blind placebo controlled study. Each subject randomly received an acid-resistant capsule containing placebo or 18 mg of quinine HCl. 60 minutes after capsule administration, the subjects underwent to an ad libitum test, until the maximum satiation. Meal test was composed by white bread, cheese and meat cream (89 kcal/portion: 50% carbohydrate, 31% fat, 19% protein). Caloric intake, meal duration and satiation levels, scored on a Visual Analogue Scale (VAS) were calculated at the end of the meal test. A questionnaire assessing GI sensations (bloating, fullness, nausea, epigastric discomfort and hunger) was administered before and at the end of the test. Data (mean ± SD) were compared by using paired t test. Results: No oral bitter sensation or side effects was observed both with quinine HCland placebo. No significant differences in terms of GI sensations and hunger feelings were observed between the two sessions of the study. The amount of calories ingested was significantly lower when subjects received quinine HCl than placebo (564±262 vs 667±278 kcal; p=0.02). Conversely, quinine HCl did not affect the meal duration (14.4±4.2 vs 16.6±4.6 min; p=NS) and the satiationintensity (82 vs 82 mm; p=NS). Conclusions: The intra-duodenal release of a bitter compound significantly decreases caloric intake in an ad libitum test meal without affecting GI sensations and hunger feeling. As the bitter compound does not influence meal duration, we hypothesize that quinine HCl decreases the caloric intake by affecting the rate of meal portions consumption. Evaluation of gut hormones kinetics and studies with other bitter taste receptor agonist are needed to establish the role of gastrointestinal bitter taste receptor in the control of food intak

CHRONIC CONSTIPATION IS A RISK FACTOR FOR METABOLIC SYNDROME

Background and aim: A recent epidemiologic survey in the U.S. provides indirect evidence that constipation is a risk factor for cardiovascular disease in postmenopausal females. To characterize the related factors involved in and to further analyse if this assumption also applies to an Italian population, we studied the impact of chronic constipation on ischemic cardiopathy and predisposing risk factors in a large population of female patients in a primary care setting. Material and methods: We retrospectively evaluated 754 female patients (mean age 46±20 years) on data file of a primary care setting. All subjects requiring medical referral for constipation were screened and presence of chronic constipation was confirmed by standardized questionnaires. The presence of clinical and/or instrumental diagnosis of ischemic cardiopathy, metabolic syndrome, diabetes and blood hypertension was scored in patients with and without chronic constipation. In all patients the consumption of drugs potentially delaying colonic transit (calcium channel blockers and beta blockers) was recorded. Patients on opioid or analgesic treatment were excluded. Results: The overall prevalence of chronic constipation was 9.4% (71/754) with the age being similar in patients with and without constipation (46±19 vs. 51±22, p=NS). The prevalence of metabolic syndrome was significantly higher in subjects with chronic constipation (5/66 vs 16/667, OR=3.1, 95% CI 1.1–8.9, p=0.03). Conversely, prevalence of diabetes, blood hypertension, ischemic cardiopathy was similar in patients with and without constipation (59/624 vs 10/61; 204/478 vs 28/43; 46/637 vs 6/65, respectively p= all NS). No significant difference was also observed as far as calcium channel blockers (64/619 vs 9/62) and beta blockers (81/602 vs 9/62) consumption in patients with or without constipation respectively. Conclusions: We showed that chronic constipation is a risk factor for metabolic syndrome in female patients. Although we did not find any significant association between chronic constipation and ischemic cardiopathy, our findings support the hypothesis that constipation may act as cardiovascular risk factor. Whether this association is dependent on dietary or hormonal factors deserves further investigation

Tumour associated vasculature-on-a-chip for the evaluation of microbubble-mediated delivery of targeted liposomes

The vascular system is the primary route for the delivery of therapeutic drugs throughout the body and is an important barrier at the region of disease interest, such as a solid tumour. The development of complex 3D tumour cultures has progressed significantly in recent years however, the generation of perfusable vascularised tumour models still presents many challenges. This study presents a microfluidic-based vasculature system that can be induced to display properties of tumour-associated blood vessels without direct incorporation of tumour cells. Conditioning healthy endothelial–fibroblast cell vasculature co-cultures with media taken from tumour cell cultures was found to result in the formation of disorganised, tortuous networks which display characteristics consistent with those of tumour-associated vasculature. Integrin αvβ3, a cell adhesion receptor associated with angiogenesis, was found to be upregulated in vasculature co-cultures conditioned with tumour cell media (TCM) – consistent with the reported αvβ3 expression pattern in angiogenic tumour vasculature in vivo. Increased accumulation of liposomes (LSs) conjugated to antibodies against αvβ3 was observed in TCM networks compared to non-conditioned networks, indicating αvβ3 may be a potential target for the delivery of drugs specifically to tumour vasculature. Furthermore, the use of microbubbles (MBs) and ultrasound (US) to further enhance the delivery of LSs to TCM-conditioned vasculature was investigated. Quantification of fluorescent LS accumulation post-perfusion of the vascular network showed 3-fold increased accumulation with the use of MBs and US, suggesting that targeted LS delivery could be further improved with the use of locally administered MBs and US

High-throughput microfluidics for evaluating microbubble enhanced delivery of cancer therapeutics in spheroid cultures

Drug penetration into solid tumours remains a major challenge in the effective treatment of cancer. Microbubble (MB) mediated sonoporation offers a potential solution to this by enhancing the uptake of drugs into cells. Additionally, in using an ultrasound (US) trigger, drug delivery can be localised to the tumour, thus reducing the off-site toxicity associated with systemic delivery. The majority of in vitro studies involving the observation of MB-enhanced drug efficacy have been conducted on 2D monolayer cell cultures, which are known to be poor models for in vivo tumours. 3D spheroid cultures allow for the production of multicellular cultures complete with extracellular matrix (ECM) components. These cultures effectively recreate many of the physiological features of the tumour microenvironment and have been shown to be far superior to previous 2D monolayer models. However, spheroids are typically handled in well-plates in which the fluid environment is static, limiting the physiological relevance of the model. The combination of 3D cultures and microfluidics would allow for the production of a dynamic system in which spheroids are subjected to in vivo like fluid flow and shear stressesThis study presents a microfluidic device containing an array of spheroid traps, into which multiple pre-grown colorectal cancer (CRC) spheroids were loaded. Reservoirs interfaced with the chip use hydrostatic pressure to passively drive flow through the system and subject spheroids to capillary like flow velocities. The use of reservoirs also enabled multiple chips to be run in parallel, allowing for the screening of multiple therapeutic treatments (n = 690 total spheroids analysed). This microfluidic platform was used to investigate MB enhanced drug delivery and showed that co-delivery of 3 μM doxorubicin (DOX) + MB + US reduced spheroid viability to 48 ± 2%, compared to 75 ± 5% observed with 3 μM DOX alone. Delivery of drug loaded MBs (DLMBs), in which DOX-loaded liposomes (DOX-LS) were conjugated to MBs, reduced spheroid viability to 62 ± 3%, a decrease compared to the 75 ± 3% viability observed with DOX-LS in the absence of MBs + US

Epithelial-Mesenchymal Transition in Cancer: Parallels Between Normal Development and Tumor Progression

From the earliest stages of embryonic development, cells of epithelial and mesenchymal origin contribute to the structure and function of developing organs. However, these phenotypes are not always permanent, and instead, under the appropriate conditions, epithelial and mesenchymal cells convert between these two phenotypes. These processes, termed Epithelial-Mesenchymal Transition (EMT), or the reverse Mesenchymal-Epithelial Transition (MET), are required for complex body patterning and morphogenesis. In addition, epithelial plasticity and the acquisition of invasive properties without the full commitment to a mesenchymal phenotype are critical in development, particularly during branching morphogenesis in the mammary gland. Recent work in cancer has identified an analogous plasticity of cellular phenotypes whereby epithelial cancer cells acquire mesenchymal features that permit escape from the primary tumor. Because local invasion is thought to be a necessary first step in metastatic dissemination, EMT and epithelial plasticity are hypothesized to contribute to tumor progression. Similarities between developmental and oncogenic EMT have led to the identification of common contributing pathways, suggesting that the reactivation of developmental pathways in breast and other cancers contributes to tumor progression. For example, developmental EMT regulators including Snail/Slug, Twist, Six1, and Cripto, along with developmental signaling pathways including TGF-β and Wnt/β-catenin, are misexpressed in breast cancer and correlate with poor clinical outcomes. This review focuses on the parallels between epithelial plasticity/EMT in the mammary gland and other organs during development, and on a selection of developmental EMT regulators that are misexpressed specifically during breast cancer

H2S biosynthesis and catabolism: new insights from molecular studies

Hydrogen sulfide (H2S) has profound biological effects within living organisms and is now increasingly being considered alongside other gaseous signalling molecules, such as nitric oxide (NO) and carbon monoxide (CO). Conventional use of pharmacological and molecular approaches has spawned a rapidly growing research field that has identified H2S as playing a functional role in cell-signalling and post-translational modifications. Recently, a number of laboratories have reported the use of siRNA methodologies and genetic mouse models to mimic the loss of function of genes involved in the biosynthesis and degradation of H2S within tissues. Studies utilising these systems are revealing new insights into the biology of H2S within the cardiovascular system, inflammatory disease, and in cell signalling. In light of this work, the current review will describe recent advances in H2S research made possible by the use of molecular approaches and genetic mouse models with perturbed capacities to generate or detoxify physiological levels of H2S gas within tissue

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe