糖肾方对糖尿病肾病大鼠肾组织TGF-β_1及MMP-9表达的影响

目的:研究糖肾方对糖尿病肾病大鼠肾组织TGF-β1、MMP-2、MMP-9及Ⅳ型胶原表达的影响,探讨糖肾方对糖尿病肾病大鼠肾脏的保护机制。方法:50只Wistar大鼠随机分为空白组、模型组、蒙诺组(0.833mg/kg)、糖肾方大剂量组(2.67g/kg)、糖肾方小剂量组(1.33g/kg),每组10只,利用单侧肾切除加腹腔注射链脲佐菌素造成糖尿病肾病大鼠模型,连续给药20周。动态检测血糖和尿蛋白/肌酐水平;取肾组织进行病理组织学观察并对肾小球硬化和肾小管间质纤维化程度进行评分;RT-PCR方法检测TGF-β1、MMP-2及MMP-9mRNA表达,免疫组化方法检测肾组织TGF-β1及Ⅳ型胶原表达。结果:大剂量糖肾方能显著降低糖尿病肾病大鼠尿蛋白/肌酐(P<0.05),降低肾小球硬化指数(P<0.01)和肾小管间质纤维化指数(P<0.01),减少TGF-β1mRNA与蛋白表达(P<0.05),增加MMP-9mRNA表达(P<0.05),减少Ⅳ型胶原蛋白表达(P<0.05)。结论:糖肾方可减轻实验大鼠肾小球硬化和肾小管间质纤维化,其作用机制可能与抑制TGF-β1表达和提高MMP-9mRNA水平有关。

嘌呤霉素氨基核苷诱发肾病综合征大鼠模型的改良制作研究

目的:在嘌呤霉素氨基核苷模型经典制作方法的基础上进行多次尾静脉追加,制作更适合慢性肾脏病药理学研究的实验性大鼠模型。方法:Wistar大鼠42只,6周龄,雄性,随机分为对照组、颈静脉给药组和追加给药组,每组14只,各组分别于造模后第30天和第56天处死动物。颈静脉给药组行颈静脉插管术缓慢推注嘌呤霉素氨基核苷(40 mg/kg),追加给药组在颈静脉给药(40 mg/kg)后第13、16、19天再进行3次小剂量尾静脉追加(5 mg/kg)。对照组给等容积0.9%生理盐水。造模后第5、10、15、20、28、42、56天时检测24 h尿蛋白。实验结束时对比两组模型的肾脏组织病理改变和血清总蛋白(TP)、白蛋白(Alb)、三酰甘油(TG)、胆固醇(TC)、肌酐(Scr)和尿素氮(BUN)水平。结果:颈静脉给药组在造模后第5天出现蛋白尿,10 d左右尿蛋白达到高峰(均值264.1 mg/24 h),随后尿蛋白急剧下降,约在第20天降至接近正常水平。追加给药组尿蛋白出现一个持续增高的平台期(均值维持在略高于150 mg/24 h的水平),末次追加后约10 d(颈静脉给药后第28天)开始缓慢下降,于第56天时接近正常。光镜所见:在30 d和56 d时,追加给药组大鼠的肾小球局灶节段性硬化和间质纤维化、炎性浸润等组织病理学指标较颈静脉给药组改变显著,其中两组之间间质纤维化的差异有统计学意义(P<0.05)。第30天血清生化结果显示,追加给药组大鼠TG、TC(P<0.05)、Scr(P<0.05)升高较明显,而颈静脉给药组变化则不明显。结论:对嘌呤霉素氨基核苷经典模型进行多次小剂量尾静脉追加,可以造成大鼠慢性肾脏病变。改良后的模型能够节约研究时限和研究成本,更适用于开展慢性肾脏病药理学研究。

糖肾方对糖尿病肾病大鼠血液流变及其相关因素的影响

目的 研究糖肾方对糖尿病肾病大鼠血液流变及其相关因素的影响.方法 40只Wistar大鼠随机分为空白组、模型组（单侧肾切除加腹腔注射链脲佐菌素造模）、糖肾方大剂量组（2.67g/kg）、糖肾方小剂量组（1.33g/kg）,每组10只,连续给药20周.动态检测体重、血糖,实验结束时腹主动脉取血检测血液黏度、总胆固醇、甘油三酯.结果 大剂量糖肾方明显降低血浆黏度、胆固醇及甘油三酯（P〈0.05或0.01）.结论 糖肾方具有促进糖尿病肾病大鼠血脂降低及改善血液流变性的作用.

糖基化终末产物及其受体在胃肠道中的分布

目的:研究糖基化终末产物(advanced glycation end products,AGE)及其受体(receptor for advanced glycation end products,RAGE)在胃肠道中的分布,为进一步探索其在慢性糖尿病胃肠功能紊乱中的作用奠定基础.方法:分别对成年Wistar大鼠食管、胃、十二指肠、空肠、回肠、结肠及直肠组织进行AGE及RAGE免疫组织化学染色.结果:(1)食管:AGE及RAGE主要分布在横纹肌的肌细胞及黏膜的鳞状上皮细胞;(2)胃:AGE在壁细胞为强阳性.RAGE在主细胞、肥大细胞、神经细胞为强阳性,在壁细胞为中等强度阳性,在表面黏液细胞为弱阳性;(3)小肠:AGE及RAGE在绒毛及固有层上皮细胞为阳性或强阳性.RAGE在肠道的神经细胞亦为强阳性;(4)结肠及直肠:AGE及RAGE在黏膜上皮细胞为弱阳性,RAGE在神经细胞为强阳性.结论:AGE及RAGE广泛分布于肠道上皮细胞及食管的横纹肌细胞,AGE亦分布于胃的壁细胞,RAGE亦分布于胃的壁细胞、主细胞、表面黏液细胞、肥大细胞及胃肠道的神经细胞.

Morphological and functional evaluation of chronic pancreatitis with magnetic resonance imaging

Magnetic resonance imaging(MRI)techniques for assessment of morphology and function of the pancreas have been improved dramatically the recent years and MRI is very often used in diagnosing and follow-up of chronic pancreatitis(CP)patients.Standard MRI including fat-suppressed T1-weighted and T2-weighted imaging techniques reveal decreased signal and glandular atrophy of the pancreas in CP.In contrast-enhanced MRI of the pancreas in CP the pancreatic signal is usually reduced and delayed due to decreased perfusion as a result of chronic inflammation and fibrosis.Thus,morphological changes of the ductal system can be assessed by magnetic resonance cholangiopancreatography(MRCP).Furthermore,secretin-stimulated MRCP is a valuable technique to evaluate side branch pathology and the exocrine function of the pancreas and diffusion weighted imaging can be used to quantify both parenchymal fibrotic changes and the exocrine function of the pancreas.These standard and advanced MRI techniques are supplementary techniques to reveal morphological and functional changes of the pancreas in CP.Recently,spectroscopy has been used for assessment of metabolite concentrations in-vivo in different tissues and may have the potential to offer better tissue characterization of the pancreas.Hence,the purpose of the present review is to provide an update on standard and advanced MRI techniques of the pancreas in CP.

Pain and chronic pancreatitis: A complex interplay of multiple mechanisms

Despite multiple theories on the pathogenesis of pain in chronic pancreatitis,no uniform and consistently successful treatment strategy exists and abdominal pain still remains the dominating symptom for most patients and a major challenge for clinicians.Traditional theories focussed on a mechanical cause of pain related to anatomical changes and evidence of increased ductal and interstitial pressures.These observations form the basis for surgical and endoscopic drainage procedures,but the outcome is variable and often unsatisfactory.This underscores the fact that other factors must contribute to pathogenesis of pain,and has shifted the focus towards a more complex neurobiological understanding of pain generation.Amongst other explanations for pain,experimental and human studies have provided evidence that pain perception at the peripheral level and central pain processing of the nociceptive information is altered in patients with chronic pancreatitis,and resembles that seen in neuropathic and chronic pain disorders.However,pain due to e.g.,complications to the disease and adverse effects to treatment must not be overlooked as an additional source of pain.This review outlines the current theories on pain generation in chronic pancreatitis which is crucial in order to understand the complexity and limitations of current therapeutic approaches.Furthermore,it may also serve as an inspiration for further research and development of methods that can evaluate the relative contribution and interplay of different pain mechanisms in the individual patients,before they are subjected to more or less empirical treatment.

New technologies to investigate the brain-gut axis

Functional gastrointestinal disorders are commonly encountered in clinical practice, and pain is their commonest presenting symptom. In addition, patients with these disorders often demonstrate a heightened sensitivity to experimental visceral stimulation, termed visceral pain hypersensitivity that is likely to be important in their pathophysiology. Knowledge of how the brain processes sensory information from visceral structures is still in its infancy. However, our understanding has been propelled by technological imaging advances such as functional Magnetic Resonance Imaging, Positron Emission To-mography, Magnetoencephalography, and Electroen-cephalography (EEG). Numerous human studies have non-invasively demonstrated the complexity involved in functional pain processing, and highlighted a number of subcortical and cortical regions involved. This review will focus on the neurophysiological pathways (primary afferents, spinal and supraspinal transmission), brain- imaging techniques and the influence of endogenous and psychological processes in healthy controls and patients suffering from functional gastrointestinal dis- orders. Special attention will be paid to the newer EEG source analysis techniques. Understanding the pheno- typic differences that determine an individual's response to injurious stimuli could be the key to understanding why some patients develop pain and hyperalgesia in response to inflammation/injury while others do not. For future studies, an integrated approach is required incorporating an individual's psychological, autonomic, neuroendocrine, neurophysiological, and genetic prof ile to def ine phenotypic traits that may be at greater risk of developing sensitised states in response to gut in? am- mation or injury.

Understanding and treatment of chronic pancreatitis

Chronic pancreatitis is characterized by an inflammatory process of the pancreas,which is replaced by fibrosis and progressive destruction.The three major clinical features of chronic pancreatitis are pain,maldigestion,and diabetes.Chronic pancreatitis has a profound impact on social life and employment patterns.In the current issue,different topics highlight experimental models of chronic pancreatitis and bridge findings from recent research to bedside.Although the disease is still difficult to treat the current papers represent useful guidelines on how to approach chronic pancreatitis in the clinical settings with the major aim to improve the patient’s suffering and quality of life.

Animal models of pancreatitis: Can it be translated to human pain study?

Chronic pancreatitis affects many individuals around the world,and the study of the underlying mechanisms leading to better treatment possibilities are important tasks.Therefore,animal models are needed to illustrate the basic study of pancreatitis.Recently,animal models of acute and chronic pancreatitis have been thoroughly reviewed,but few reviews address the important aspect on the translation of animal studies to human studies.It is well known that pancreatitis is associated with epigastric pain,but the understanding regarding to mechanisms and appropriate treatment of this pain is still unclear.Using animal models to study pancreatitis associated visceral pain is difficult,however,these types of models are a unique way to reveal the mechanisms behind pancreatitis associated visceral pain.In this review,the animal models of acute,chronic and un-common pancreatitis are briefly outlined and animal models related to pancreatitis associated visceral pain are also addressed.

Nutrition in chronic pancreatitis

The pancreas is a major player in nutrient digestion.In chronic pancreatitis both exocrine and endocrine insufficiency may develop leading to malnutrition over time.Maldigestion is often a late complication of chronic pancreatic and depends on the severity of the underlying disease.The severity of malnutrition is correlated with two major factors:(1)malabsorption and depletion of nutrients(e.g.,alcoholism and pain)causes impaired nutritional status;and(2)increased metabolic activity due to the severity of the disease.Nutritional deficiencies negatively affect outcome if they are not treated.Nutritional assessment and the clinical severity of the disease are important for planning any nutritional intervention.Good nutritional practice includes screening to identify patients at risk,followed by a thoroughly nutritional assessment and nutrition plan for risk patients.Treatment should be multidisciplinary and the mainstay of treatment is abstinence from alcohol,pain treatment,dietary modifications and pancreatic enzyme supplementation.To achieve energy-end protein requirements,oral supplementation might be beneficial.Enteral nutrition may be used when patients do not have sufficient calorie intake as in pylero-duodenalstenosis,inflammation or prior to surgery and can be necessary if weight loss continues.Parenteral nutrition is very seldom used in patients with chronic pancreatitis and should only be used in case of GI-tract obstruction or as a supplement to enteral nutrition.

Gastrointestinal tract modelling in health and disease

The gastrointestinal (GI) tract is the system of organs within multi-cellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. The various patterns of GI tract function are generated by the integrated behaviour of multiple tissues and cell types. A thorough study of the GI tract requires understanding of the interactions between cells, tissues and gastrointestinal organs in health and disease. This depends on knowledge, not only of numerous cellular ionic current mechanisms and signal transduction pathways, but also of large scale GI tissue structures and the special distribution of the nervous network. A unique way of coping with this explosion in complexity is mathematical and computational modelling; providing a computational framework for the multilevel modelling and simulation of the human gastrointestinal anatomy and physiology. The aim of this review is to describe the current status of biomechanical modelling work of the GI tract in humans and animals, which can be further used to integrate the physiological, anatomical and medical knowledge of the GI system. Such modelling will aid research and ensure that medical professionals benefit, through the provision of relevant and precise information about the patient's condition and GI remodelling in animal disease models. It will also improve the accuracy and efficiency of medical procedures, which could result in reduced cost for diagnosis and treatment.

Pharmacological challenges in chronic pancreatitis

Drug absorption in patients with chronic pancreatitis might be affected by the pathophysiology of the disease.The exocrine pancreatic insufficiency is associated with changes in gastrointestinal intraluminal pH,motility disorder,bacterial overgrowth and changed pancreatic gland secretion.Together these factors can result in malabsorption and may also affect the efficacy of pharmacological intervention.The lifestyle of chronic pancreatitis patients may also contribute to gastrointestinal changes.Many patients limit their food intake because of the pain caused by eating and in some cases food intake is more or less substituted with alcohol,tobacco and coffee.Alcohol and drug interaction are known to influence the pharmacokinetics by altering either drug absorption or by affecting liver metabolism.Since patients suffering from chronic pancreatitis experience severe pain,opioids are often prescribed as pain treatment.Opioids have intrinsic effects on gastrointestinal motility and hence can modify the absorption of other drugs taken at the same time.Furthermore,the increased fluid absorption caused by opioids will decrease water available for drug dissolution and may hereby affect absorption of the drug.As stated above many factors can influence drug absorption and metabolism in patients with chronic pancreatitis.The factors may not have clinical relevance,but may explain inter-individual variations in responses to a given drug,in patients with chronic pancreatitis.

Axial force measurement for esophageal function testing

The esophagus serves to transport food and fluid from the pharynx to the stomach. Manometry has been the "golden standard" for the diagnosis of esophageal motility diseases for many decades. Hence, esophageal function is normally evaluated by means of manometry even though it reflects the squeeze force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe with combined axial force and manometry recordings showed that axial force amplitude increased by 130% in contrast to an increase of 30% using manometry. Using axial force in combination with manometry provides a more complete picture of esophageal motility, and the current paper outlines the advantages of using this method.

Assessment of the cardiovascular and gastrointestinal autonomic complications of diabetes

The global prevalence of diabetes mellitus is increasing; arguably as a consequence of changes in diet, lifestyle and the trend towards urbanization. Unsurprisingly, the incidence of both micro and macrovascular complications of diabetes mirrors this increasing prevalence. Amongst the complications with the highest symptom burden, yet frequently under-diagnosed and sub-optimally treated, is diabetic autonomic neuropathy, itself potentially resulting in cardiovascular autonomic neuropathy and gastrointestinal(GI) tract dysmotility. The aims of this review are fourfold. Firstly to provide an overview of the pathophysiological processes that cause diabetic autonomic neuropathy. Secondly, to discuss both the established and emerging cardiometric methods for evaluating autonomic nervous system function in vivo. Thirdly, to examine the tools for assessing pan-GI and segmental motility and finally, we will provide the reader with a summary of putative non-invasive biomarkers that provide a pathophysiological link between lowgrade neuro inflammation and diabetes, which may allow earlier diagnosis and intervention, which in future may improve patient outcomes.

Translational pain research: Evaluating analgesic effect in experimental visceral pain models

Deep visceral pain is frequent and presents major challenges in pain management, since its pathophysiology is still poorly understood. One way to optimize treatment of visceral pain is to improve knowledge of the mechanisms behind the pain and the mode of action of analgesic substances. This can be achieved through stand-ardized experimental human pain models. Experimental pain models in healthy volunteers are advantageous for evaluation of analgesic action, as this is often diff icult to assess in the clinic because of confounding factors such as sedation, nausea and general malaise. These pain models facilitate minimizing the gap between knowledge gained in animal and human clinical studies. Combining experimental pain studies and pharmacokinetic stud- ies can improve understanding of the pharmacokinetic-pharmacodynamic relationship of analgesics and, thus, provide valuable insight into optimal clinical treatment of visceral pain. To improve treatment of visceral pain, it is important to study the underlying mechanisms of pain and the action of analgesics used for its treatment. An experimental pain model activates different modalities and can be used to investigate the mechanism of action of different analgesics in detail. In combination with pharmacokinetic studies and objective assessment such as electroencephalography, new information re-garding a given drug substance and its effects can be obtained. Results from experimental human visceral pain research can bridge the gap in knowledge between animal studies and clinical condition in patients suffering from visceral pain, and thus constitute the missing link in translational pain research.

New technologies in gastrointestinal research

This issue presents different new techniques aiming to increase our understanding of the gastrointestinal system and to improve treatment. The technologies cover selected methods to evoke and assess gut pain, new methods for imaging and physiological measurements, histochemistry, pharmacological modelling etc. There is no doubt that the methods will revolutionize the diagnostic approach in near future.

Mucosal blood flow measurements using laser Doppler perfusion monitoring

Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level. Ischemia, or the insuff iciency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including pain. It is of considerable interest to study perfusion of pe- ripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including peptic ulcer disease, inflammatory bowel disease and chest pain. The basic principle of laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastroin-testinal (GI) tract using LDPM. In recent years we have developed a multi-modal catheter device which includes a laser Doppler probe, with the intent primarily to investigate patients suffering from functional chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results.

Brain changes in diabetes mellitus patients withgastrointestinal symptoms

Diabetes mellitus is a common disease and its prevalence is increasing worldwide. In various studies up to 30%-70% of patients present dysfunction and complications related to the gut. To date several clinical studies have demonstrated that autonomic nervous system neuropathy and generalized neuropathy of the central nervous system(CNS) may play a major role. This systematic review provides an overview of the neurodegenerative changes that occur as a consequence of diabetes with a focus on the CNS changes and gastrointestinal(GI) dysfunction. Animal models where diabetes was induced experimentally support that the disease induces changes in CNS. Recent investigations with electroencephalography and functional brain imaging in patients with diabetes confirm these structural and functional brain changes. Encephalographic studies demonstrated that altered insular processing of sensory stimuli seems to be a key player in symptom generation. In fact one study indicated that the more GI symptoms the patients experienced, the deeper the insular electrical source was located. The electroencephalography was often used in combination with quantitative sensory testingmainly showing hyposensitivity to stimulation of GI organs. Imaging studies on patients with diabetes and GI symptoms mainly showed microstructural changes,especially in brain areas involved in visceral sensory processing. As the electrophysiological and imaging changes were associated with GI and autonomic symptoms they may represent a future therapeutic target for treating diabetics either pharmacologically or with neuromodulation.

Sensory testing of the human gastrointestinal tract

The objective of this appraisal is to shed light on the various approaches to screen sensory information in the human gut. Understanding and characterization of sensory symptoms in gastrointestinal disorders is poor. Experimental methods allowing the investigator to control stimulus intensity and modality, as well as using validated methods for assessing sensory response have contributed to the understanding of pain mechanisms. Mechanical stimulation based on impedance planimetry allows direct recordings of luminal cross-sectional areas, and combined with ultrasound and magnetic resonance imaging, the contribution of different gut layers can be estimated. Electrical stimulation depolarizes free nerve endings non-selectively. Consequently, the stimulation paradigm (single, train, tetanic) influences the involved sensory nerves. Visual controlled electrical stimulation combines the probes with an endoscopic approach, which allows the investigator to inspect and obtain small biopsies from the stimulation site. Thermal stimulation (cold or warm) activates selectively mucosal receptors, and chemical substances such as acid and capsaicin (either alone or in combination) are used to evoke pain and sensitization. The possibility of multimodal (e.g. mechanical, electrical, thermal and chemical) stimulation in different gut segments has developed visceral pain research. The major advantage is involvement of distinctive receptors, various sensory nerves and different pain pathways mimicking clinical pain that favors investigation of central pain mechanisms involved in allodynia, hyperalgesia and referred pain. As impairment of descending control mechanisms partly underlies the pathogenesis in chronic pain, a cold pressor test that indirectly stimulates such control mechanisms can be added. Hence, the methods undoubtedly represent a major step forward in the future characterization and treatment of patients with various diseases of the gut, which provides knowledge to clinicians about the underlying symptoms and treatment of these patients.

Imaging of the gastrointestinal tract-novel technologies

Imaging of the gastrointestinal tract is very useful for research and clinical studies of patients with symptoms arising from the gastrointestinal tract and in visualising anatomy and pathology. Traditional radiological techniques played a leading role in such studies for a long time. However, advances in non-invasive modalities including ultrasound (US), computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), etc, have in the last decades revolutionised the way in which the gastrointestinal tract is studied. The resolution of imaging data is constantly being improved and 3D acquisition, tools for fi ltering, enhancement, segmentation and tissue classif ication are continually being developed. Additional co-registration techniques allow multimodal data acquisition with improved classif ication of tissue pathology. Furthermore, new functional imaging techniques have become available. Altogether, the future of gastrointestinal imaging looks very promising which will be of great benef it in clinical and research studies of gastrointestinal diseases. The purpose of this review is to highlight the capabilities of the newest techniques to explore the detailed morphology, biomechanical properties, function and pathology of the gastrointestinal tract.