Στην βιολογία, το περιβάλλον μπορεί να καθοριστεί σαν ενα σύνολο κλιματικών, βιοτικών, κοινωνικών και εδαφικών παραγόντων που δρουν σε έναν οργανισμό και καθορίζουν την ανάπτυξη και την επιβίωση του. Έτσι, περιλαμβάνει οτιδήποτε μπορεί να επηρεάσει άμεσα τον μεταβολισμό ή τη συμπεριφορά των ζωντανών οργανισμών ή ειδών, όπως το φως, ο αέρας, το νερό, το έδαφος και άλλοι παράγοντες. Δείτε επίσης το άρθρο για το φυσικό περιβάλλον και τη φυσική επιλογή.
Στην αρχιτεκτονική, την εργονομία και την ασφάλεια στην εργασία, περιβάλλον είναι το σύνολο των χαρακτηριστικών ενός δωματίου ή κτιρίου που επηρεάζουν την ποιότητα ζωής και την αποδοτικότητα, περιλαμβανομένων των διαστάσεων και της διαρρύθμισης των χώρων διαβίωσης και της επίπλωσης, του φωτισμού, του αερισμού, της θερμοκρασίας, του θορύβου κλπ. Επίσης μπορεί να αναφέρεται στο σύνολο των δομικών κατασκευών. Δείτε επίσης το άρθρο για το δομημένο περιβάλλον.
Στην ψυχολογία, περιβαλλοντισμός είναι η θεωρία ότι το περιβάλλον (με τη γενική και κοινωνική έννοια) παίζει μεγαλύτερο ρόλο από την κληρονομικότητα καθορίζοντας την ανάπτυξη ενός ατόμου. Συγκεκριμένα, το περιβάλλον είναι ένας σημαντικός παράγοντας πολλών ψυχολογικών θεωριών.
Στην τέχνη, το περιβάλλον αποτελεί κινητήριο μοχλό και μούσα εμπνέοντας τους ζωγράφους ή τους ποιητές. Σε όλες τις μορφές της Τέχνης αποτελεί έμπνευση και οι Καλές Τέχνες φανερώνουν την επιρροή οπού άσκησε σε όλους τους καλλιτέχνες με όποιο είδος Τέχνης κι αν ασχολούνται. Ο άνθρωπος μέσα στο περιβάλλον δημιουργεί Μουσική, Ζωγραφική, Ποίηση, Γλυπτική, χορό, τραγούδι, θέατρο, αλλά και όλες οι μορφές τέχνης έχουν άμεση έμπνευση από το περιβάλλον.

Πέμπτη 11 Ιουλίου 2019

Gastroenterology

The Utility of Esophageal Motility Testing in Gastroesophageal Reflux Disease (GERD)

Abstract

Purpose of Review

Here, we discuss how esophageal motor testing plays important roles in patients with suspected gastroesophageal reflux disease (GERD). In addition to guiding appropriate placement of catheters for ambulatory reflux monitoring, esophageal high-resolution manometry (HRM) rules out confounding diagnoses, such as achalasia spectrum disorders, that can present with symptoms similar to that of GERD, but are managed very differently.

Recent Findings

HRM performed with impedance in the post-prandial setting (PP-HRIM) can assess for rumination syndrome or supragastric belching, which should be directed towards behavioral interventions. The recent GERD Classification of Motor Function recommends a hierarchical approach, focusing on (1) the esophagogastric junction (EGJ), (2) the esophageal body, and (3) esophageal contraction reserve, which can be assessed with provocative maneuvers at HRM, such as multiple rapid swallows (MRS). This approach can inform the appropriate tailoring of antireflux surgery. Novel esophageal motility metrics, such as the EGJ-contractile integral from HRM, or post-reflux swallow-induced peristaltic wave indices from 24-h pH-impedance monitoring, may also assist with GERD diagnosis.

Summary

Assessment of esophageal motor function can contribute in a significant manner to the care of patients with suspected GERD, particularly when esophageal symptoms do not improve with antisecretory therapy, and/or when surgical or endoscopic antireflux therapies are under consideration.



Duodenal Chemosensing of Short-Chain Fatty Acids: Implications for GI Diseases

Abstract

Purpose of Review

Short-chain fatty acids (SCFAs), the main bacterial fermentation products in the hindgut of hindgut fermenters, are also present in the foregut lumen. We discuss the impact of SCFAs in the duodenal defense mechanisms and in the gastrointestinal (GI) pathogenesis.

Recent Findings

Luminal SCFAs augment the duodenal mucosal defenses via release of serotonin (5-HT) and glucagon-like peptide-2 (GLP-2) from enteroendocrine cells. Released GLP-2 protects the small intestinal mucosa from nonsteroidal anti-inflammatory drug-induced enteropathy. SCFAs are also rapidly absorbed via SCFA transporters and interact with afferent and myenteric nerves. Excessive SCFA signals with 5-HT3 receptor overactivation may be implicated in the pathogenesis of irritable bowel syndrome symptoms. SCFA production exhibits diurnal rhythms with host physiological responses, suggesting that oral SCFA treatment may adjust the GI clocks.

Summary

SCFAs are not only a source of energy but also signaling molecules for the local regulation of the GI tract and systemic regulation via release of gut hormones. Targeting SCFA signals may be a novel therapeutic for GI diseases and metabolic syndrome.



Gastroduodenal Injury: Role of Protective Factors

Abstract

Purpose of Review

The gastroduodenal mucosal layer is a complex and dynamic system that functions in an interdependent manner to resist injury. We review and summarize the most updated knowledge about gastroduodenal defense mechanisms and specifically address (a) the mucous barrier, (b) membrane and cellular properties, and vascular, hormonal, and (c) gaseous mediators.

Recent Findings

Trefoil factor family peptides play a crucial role in cellular restitution by increasing cellular permeability and expression of aquaporin channels, aiding cellular migration and tissue repair. Additionally, evidence suggests that the symptoms of functional dyspepsia may be attributed to alterations in the duodenum, including low-grade inflammation and increased mucosal permeability.

Summary

The interaction of the various mucosal protective components helps maintain structural and functional homeostasis. There is increasing evidence suggesting that the upper GI microbiota plays a crucial role in the defense mechanisms. However, this warrants further investigation.



The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

Abstract

Purpose of Review

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

Recent Findings

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development.

Summary

CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.



Nutrition in Cirrhosis

Abstract

Purpose of Review

This review discusses the prevalence of malnutrition in cirrhosis, metabolic functions of the liver and alterations in cirrhosis, malnutrition screening tools, and common macronutrient and micronutrient deficiencies encountered in individuals with chronic liver disease and their impact on morbidity and mortality.

Recent Findings

Several meta-analyses and international society guidelines recommend malnutrition screening and nutrition interventions to improve outcomes in all patients with chronic liver disease given their high risk of malnutrition which is often under recognized.

Summary

Malnutrition is common in individuals with chronic liver disease and has a significant impact on patient outcomes. Thus, it is critical that validated malnutrition screening tools are used routinely in this patient population in order to identify high-risk patients and implement nutrition and exercise interventions early.



Popular Remedies for Esophageal Symptoms: a Critical Appraisal

Abstract

Purpose of Review

Popular remedies are of ongoing interest to patients experiencing common esophageal symptoms, particularly as typical pharmacologic interventions have been subject to increased scrutiny. Herein we summarize the available data regarding potential risks and benefits of several such remedies.

Recent Findings

With emphasis on reflux and non-cardiac chest pain, research is ongoing into the clinical utility and diverse physiologic mechanisms underlying a variety of complementary and alternative modalities, including dietary manipulation, apple cider vinegar, melatonin, acupuncture, and various herbal products (rikkunshito, STW 5, slippery elm, licorice, and peppermint oil, among others).

Summary

A substantial gap persists between anecdotal and empirical understandings of the majority of non-pharmacologic remedies for esophageal symptoms. This landscape of popular treatments nevertheless raises several interesting mechanistic hypotheses and compelling opportunities for future research.



Colonic and Anorectal Manifestations of Systemic Sclerosis

Abstract

Purpose of Review

Systemic sclerosis is a chronic autoimmune disorder commonly involving the gastrointestinal tract, including the colon and anorectum. In this review, we summarize major clinical manifestations and highlight recent developments in physiology, diagnostics, and treatment.

Recent Findings

The exact pathophysiology of systemic sclerosis is unclear and likely multifactorial. The role of the microbiome on gastrointestinal manifestations has led to a better understanding of potential pathogenic gut flora. Carbohydrate malabsorption is common. Evaluation using fecal calprotectin and high-resolution anorectal manometry may broaden our understanding of the etiologies of diarrhea and fecal incontinence and help with early recognition of pathology. Prucalopride, a high-affinity 5HT4 agonist, and pyridostigmine, an acetylcholinesterase inhibitor, may help improve colonic transit in patients with constipation. Intravenous immunoglobulins have been used to target muscarinic receptor antibodies that are believed to contribute to gastrointestinal dysmotility.

Summary

Colonic and anorectal manifestations of systemic sclerosis include constipation, diarrhea, and fecal incontinence, and can diminish quality of life for these patients. Recent studies regarding pathophysiology as well as diagnostic and treatment options are promising. Further targeted studies to facilitate early intervention and better management of refractory symptoms are still needed.



Evaluation and Management of Cirrhotic Patients Undergoing Elective Surgery

Abstract

Purpose of Review

Cirrhotic patients have an increased risk of surgical complications and higher perioperative morbidity and mortality based on the severity of their liver disease. Liver disease predisposes patients to perioperative coagulopathies, volume overload, and encephalopathy. The goal of this paper is to discuss the surgical risk of cirrhotic patients undergoing elective surgeries and to discuss perioperative optimization strategies.

Recent Findings

Literature thus far varies by surgery type and the magnitude of surgical risk. CTP and MELD classification scores allow for the assessment of surgical risk in cirrhotic patients.

Summary

Once the decision has been made to undergo elective surgery, cirrhotic patients can be optimized pre-procedure with the help of a checklist and by the involvement of a multidisciplinary team. Elective surgeries should be performed at hospital centers staffed by healthcare providers experienced in caring for cirrhotic patients. Further research is needed to develop ways to prepare this complicated patient population before elective surgery.



The Status of SEMS Versus Plastic Stents for Benign Biliary Strictures

Abstract

Purpose of Review

Benign biliary strictures can be treated with plastic stents and self-expandable metal stents (SEMS). This review article delineates the latest scientific evidence for their usage.

Recent Findings

Despite evolving literature on both type of stents as treatment modalities of benign biliary strictures, which encompass mainly anastomotic strictures and strictures related to chronic pancreatitis, no final conclusions can be drawn regarding the superiority of a particular stent. SEMS tend to have higher stricture resolution rates and fewer procedural requirements which are partly offset by higher stent migration and stricture recurrence rates compared with plastic stents.

Summary

Additional studies focusing on new SEMS types with anti-migration features as well as cost-effectiveness calculations are necessary for clinical decision-making when treating patients with benign biliary strictures.



Clinical Aspects of Thickeners for Pediatric Gastroesophageal Reflux and Oropharyngeal Dysphagia

Abstract

Purpose of Review

The purpose of this review is to discuss current knowledge and recent findings regarding clinical aspects of thickeners for pediatric gastroesophageal reflux and oropharyngeal dysphagia. We review evidence for thickener efficacy, discuss types of thickeners, practical considerations when using various thickeners, and risks and benefits of thickener use in pediatrics.

Recent Findings

Thickeners are effective in decreasing regurgitation and improving swallowing mechanics and can often be used empirically for the treatment of infants and young children. Adverse effects have been reported, but with careful consideration of appropriate thickener types, desired thickening consistency, and follow-up in collaboration with feeding specialists, most patients have symptomatic improvements.

Summary

Thickeners are typically well tolerated and with few side effects, but close follow-up is needed to make sure patients tolerate thickeners and have adequate symptom improvement.



Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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