Analysis of abdominal wounds made by surgical trocars using functional luminal imaging probe (FLIP) technology.

The aim was to use a novel functional luminal imaging probe for evaluation of wound defects and tissue damage resulting from the use of trocars. Following general anesthesia of 4 adult pigs, 6 different trocars were randomly inserted at preselected locations in the porcine abdominal wall. The functional luminal imaging probe was used to profile the trocar holes during bag distension from 8 axial cross-sectional area measurements.

Effect of smooth muscle tone on morphometry and residual strain in rat duodenum, jejunum and ileum.

It is difficult to measure gastrointestinal smooth muscle (SM) tone except in sphincter regions. Since tone affects the biomechanical properties, the aim of the present study was to evaluate intestinal SM tone by studying the morphometry and biomechanical properties with and without muscle tone. Circumferential rings of 0.

Phasic and tonic stress-strain data obtained in intact intestinal segment in vitro.

The function of the small intestine is to a large degree mechanical, and it has the capability of deforming its shape by generating phasic (short-lasting) and tonic (sustained) contraction of the smooth muscle layers. The aim of this study was to obtain phasic and tonic stress-strain (normalized force-length) curves during distension of isolated rat jejunum and ileum (somewhat similar to the isometric length-tension diagram known from in vitro studies of muscle strips). We hypothesized that the circumferential stress-strain data depend on longitudinal stretch of the intestine.

Autoimmune pancreatitis: expression and cellular source of profibrotic cytokines and their receptors.

Chronic pancreatitis is a fibrogenic disease. In autoimmune pancreatitis (AIP), a lymphoplasmacytic infiltration is followed by fibrosis. In vitro it has been shown that pancreatic stellate cells are transformed into proliferating myofibroblasts mainly by transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF).

Numerical analysis of pouch filling and emptying after laparoscopic gastric banding surgery.

Background: Previous studies have indicated that pouch volume and stoma size are two important factors related to weight loss after laparoscopic gastric banding in morbid obese patients. We hypothesized that there was association among the wall stress, pouch volume, and stoma size in a model for the filling and emptying phases of the pouch.

Methods: A numerical pouch model with variable pouch volume and stoma size was generated.

The villi contribute to the mechanics in the guinea pig small intestine.

Previous studies have shown that intestinal mucosa is compressed in vivo. The present study investigated the contribution of the mucosal villi to the biomechanical properties in circumferential direction in the guinea pig jejunum. Eight 20-cm-long jejunal segments were excised and each separated into two 10-cm-long segments.

Effects of nandrolone on denervation atrophy depend upon time after nerve transection.

Anabolic steroids prevent disuse atrophy and reverse atrophy caused by glucocorticoids. To determine whether these beneficial effects extend to denervation atrophy, we tested whether nandrolone blocked denervation atrophy acutely or reversed subacute denervation atrophy. We also tested the association of such anabolic effects with expression of MAFbx, MuRF1 (both of which accelerate denervation atrophy), and IGF-1 (which prevents such atrophy).

Use of a derivative of Escherichia coli BL21(DE3) for efficient production of three different recombinant proteins.

Plasmid instability and growth inhibition of plasmid-bearing cells after induction were encountered when E. coli BL21(DE3) was used as host for the production of antihuman ovarian carcinoma x antihuman CD3 single-chain bispecific antibody (AhOC x AhCD3), human soluble B lymphocyte stimulator fused with thioredoxin (Trx-hsBLyS) and human parathyroid hormone fused with thioredoxin (Trx-hPTH). A derivative of BL21(DE3), namely, BLRM(DE3), isolated and showing superiority in AhOC x AhCD3 production in our previous work, was further used here for more efficient production of these three different recombinant proteins.

[Relationship between aldosterone synthase gene (CYP11B2) polymorphisms and essential hypertension in a northern Chinese Han population].

Objective: To explore the relationship between genetic polymorphisms of C-344T in the promoter region and K173R in the exon 3 of aldosterone synthase gene (CYP11B2) and the incidence of essential hypertension in a northern Chinese Han population.

Methods: We conducted a case-control study including 182 hypertensive patients and 189 healthy controls in Harbin newspaper office and assayed the genotypes of C-344T and K173R using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing technology.

Results: The distributions of C-344T and K173R genotype frequencies in men and women were in accordance with the Hardy-Weinberg equilibrium.

Identification of Escherichia coli host cell for high plasmid stability and improved production of antihuman ovarian carcinoma x antihuman CD3 single-chain bispecific antibody.

To improve the plasmid stability during the production of antihuman ovarian carcinoma x antihuman CD3 single-chain bispecific antibody (AhOCxAhCD3), the Escherichia coli BL21(DE3) host cell was optimized serially. Firstly, an isogenic recombination-deficient (recA (-)) derivative of BL21(DE3), namely BLR(DE3), was used as host instead of BL21(DE3). Although the segregational plasmid stability was greatly improved, AhOCxAhCD3 yield was not improved due to the severe growth inhibition of plasmid-bearing BLR(DE3) cells and the competitive plasmid instability after induction.

Spontaneous and bolus-induced motility in the chronically obstructed guinea-pig small intestine in vitro.

Partial obstruction of the small intestine results in dysmotility and morphometric changes proximal to the site of obstruction. However, our understanding of the relation between the morphometric remodeling and change in the motility pattern during chronic obstruction is sparse. The aim of this study was to investigate the effect of partial chronic intestinal obstruction on motility, morphology, and collagen content proximal and distal to the site of obstruction.

Remodelling of the zero-stress state and residual strains in apoE-deficient mouse aorta.

Atherosclerosis is the most frequent cause of death and severe chronic disability in North America and Europe. The atherosclerosis-prone apolipoprotein E (apoE)-deficient mice contain the entire spectrum of lesions observed during atherogenesis. Significant remodelling of the artery occurs in atherosclerosis.

Opening angle and residual strain in a three-layered model of pig oesophagus.

Studies of various biological tissues have shown that residual strains are important for tissue function. Since a force balance exists in whole wall thickness specimens cut radially, it is evident that layer separation is an important procedure in the understanding of the meaning of residual stresses and strains. The present study investigated the zero-stress state and residual strain distribution in a three-layer model of the pig oesophagus.

The oesophageal zero-stress state and mucosal folding from a GIOME perspective.

The oesophagus is a cylindrical organ with a collapsed lumen and mucosal folds. The mucosal folding may serve to advance the function of the oesophagus, i.e.

Identification of androgen response elements in the insulin-like growth factor I upstream promoter.

Testosterone stimulates the expression of IGF-I in cells and tissues that include prostate, muscle and muscle satellite cells, and the uterus. Here, the molecular mechanisms of this effect of testosterone were explored. Testosterone increased IGF-I mRNA levels in HepG2 and LNCaP cells and stimulated the activity of reporter genes controlled by 1.

Dimensions and circumferential stress-strain relation in the porcine esophagus in vitro determined by combined impedance planimetry and high-frequency ultrasound.

The mechanical properties of the esophagus are important for its function because the esophagus is subjected to changes in wall stress and strains caused by the passage of boli and the action of peristalsis. Electrodes for impedance planimetry and an ultrasound transducer were placed on the probe inside a fluid-filled bag and used to study the circumferential stress and strain relation of the porcine esophagus in vitro. Impedance planimetry was used to determine the luminal cross-sectional area (CSA) and high-frequency ultrasound was used to determine the esophageal wall thickness during bag distension.

iNOS expression in rat aorta is increased after spinal cord transection: a possible cause of orthostatic hypotension in man.

Orthostatic hypotension commonly occurs in persons with spinal cord injury (SCI), limiting rehabilitation and independence. Findings of increased production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) after exposure to simulated microgravity suggest that increased iNOS expression contributes to OH in persons with SCI. To test this possibility, male Wistar rats underwent surgical transection of the spinal cord (T10) or sham-SCI surgery followed by euthanasia 3, 7 or 14 days later.

Biomechanical remodeling of the chronically obstructed Guinea pig small intestine.

Small intestinal obstruction is a frequently encountered clinical problem. To understand the mechanisms behind obstruction and the clinical consequences, data are needed on the relation between the morphologic and biomechanical remodeling that takes place in the intestinal wall during chronic obstruction. We sought to determine the effect of partial obstruction on mechanical and morphologic properties of the guinea pig small intestine.

Biomechanical and histomorphometric esophageal remodeling in type 2 diabetic GK rats.

Diabetes mellitus induces remodeling of the morphology and mechanical properties in the gastrointestinal tract. This study aimed to investigate the histomorphometric and biomechanical remodeling of esophagus in the diabetic type 2 model Goto-Kakizaki (GK) rats. Five male diabetic GK rats and five male nondiabetic Wistar rats were used in this study.

Manual pressure distension of the human saphenous vein changes its biomechanical properties-implication for coronary artery bypass grafting.

Patency rates of saphenous vein grafts following coronary artery bypass grafting (CABG) depend on multiple factors. Information regarding the impact of biomechanical properties of vein grafts on patency rates is not available. The objective of the present study was to evaluate whether uncontrolled manual pressure distension during routine preparation of the saphenous vein in CABG-induced changes in the biomechanical properties of the vein.

Effect of Kaiyu Qingwei Jianji on the morphometry and residual strain distribution of small intestine in experimental diabetic rats.

Aim: To investigate the effect of a Chinese medicine, Kaiyu Qingwei Jianji (KYQWJJ) used for diabetic treatment, on the morphometry and residual strain distribution of the small intestine in streptozotocin (STZ) -induced diabetic rats. Correlation analysis was also performed between the opening angle and residual strain with the blood glucose level.

Methods: Forty-two male Wistar rats weighing 220-240 g were included in this study.

The geometric configuration and morphometry of the rabbit oesophagus during luminal pressure loading.

The aim of the present study was to determine the geometric configuration and morphometric dimensions in the rabbit oesophagus during luminal pressure loading. The geometric configuration is of fundamental importance because it is related to stress and strain and determines the resistance to flow. The oesophagus was excised from rabbits, transferred to an organ bath and stretched to the in vivo length.

Longitudinal residual strain and stress-strain relationship in rat small intestine.

Background: To obtain a more detailed description of the stress-free state of the intestinal wall, longitudinal residual strain measurements are needed. Furthermore, data on longitudinal stress-strain relations in visceral organs are scarce. The present study aims to investigate the longitudinal residual strain and the longitudinal stress-strain relationship in the rat small intestine.

Three-dimensional surface model analysis in the gastrointestinal tract.

The biomechanical changes during functional loading and unloading of the human gastrointestinal (GI) tract are not fully understood. GI function is usually studied by introducing probes in the GI lumen. Computer modeling offers a promising alternative approach in this regard, with the additional ability to predict regional stresses and strains in inaccessible locations.

Upper gastrointestinal sensory-motor dysfunction in diabetes mellitus.

Gastrointestinal (GI) sensory-motor abnormalities are common in patients with diabetes mellitus and may involve any part of the GI tract. Abnormalities are frequently sub-clinical, and fortunately only rarely do severe and life-threatening problems occur. The pathogenesis of abnormal upper GI sensory-motor function in diabetes is incompletely understood and is most likely multi-factorial of origin.