Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q16637 (SMA)
 8,107 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Our in vivo model of mesenteric ischemia/reperfusion (I/R) has shown that the gut serves as a priming bed for neutrophils (PMN). Activation of phospholipase A2 (PLA2) during ischemia temporally precedes PMN sequestration in the gut and the appearance of primed PMN in the portal circulation. Therefore, we hypothesized that reperfused gut secretes platelet activating factor (PAF) via PLA2 activation that is responsible for increased PMN chemotaxis and priming for superoxide (O2-) generation. Sprague-Dawley rats underwent gut ischemia/reperfusion (45 min SMA occlusion/2 hr reperfusion) or sham laparotomy. Distal ileum was harvested, rinsed with bacteriostatic saline/neomycin, and incubated for 1 hr at 37 degrees C in RPMI 1640 and the cell-free supernatant was collected. Normal human PMNs, isolated by plasma-Percoll gradients, were pretreated with or without a PAF receptor antagonist (WEB 2170). Chemotaxis toward gut supernatant was then measured by the agarose method. Additionally, PMNs were preincubated with or without WEB 2170 and their O2- release in response to 1 microM FMLP was measured by the Vmax of SOD-inhibitable cytochrome c reduction. Reperfused gut produced a chemotactic index of 2.1 +/- 0.1 compared to 0.2 +/- 0.9 following sham laparotomy (P < 0.05); this was reduced to 0.4 +/- 0.9 with PAF receptor blockade. Similarly, gut I/R supernatant primed PMNs for O2- (P < 0.05) compared to laparotomy, and this effect was abrogated by a PAF antagonist. These data suggest that reperfused gut can elaborate PAF which chemoattracts and primes PMNs for O2- generation.
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PMID:Reperfused gut elaborates PAF that chemoattracts and primes neutrophils. 779 40

The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3 +/- 46.8 ml/min (mean +/- standard error) during the fasting state, and 714.7 +/- 207.7 ml/min, 339.2 +/- 85.7 ml/min, and 263.8 +/- 21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p < 0.05). The corresponding flow measurements in the IMA were 63.1 +/- 11.2 ml/min, 67.6 +/- 11.2 ml/min, 57.9 +/- 8.6 ml/min, and 53.2 +/- 6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia.
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PMID:Flow velocity and volume measurement of superior and inferior mesenteric artery with cine phase contrast magnetic resonance imaging. 786 25

The relationships between superior mesenteric artery blood flow (SMABF) and pulsatility index (PI) measurement during rest (25 subjects) and stimuli constricting the SMA (16 subjects) have been studied in normal subjects. At rest and during constrictor stimuli, SMABF and PI were highly reproducible (r = 0.89, p < 0.01 for SMABF, and r = 0.97, p < 0.001 for PI) between two observers. There was significant correlation between changes in SMABF, PI, and SMA vascular resistance during the constrictor stimuli, except during head-up tilt when PI was unchanged. Both PI and SMABF measurements are reproducible and can be used to monitor physiological changes in suitable (18 of 25) subjects. PI measurement, although semiquantitative, by itself can also be used to monitor these changes. This may be also of importance in pathological situations such as intestinal ischemia, where measurement of volume blood flow may be less accurate due to irregularities of the vessel wall. PI measurement, however, ideally should not be used in studies involving postural change.
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PMID:The relationship between blood flow and pulsatility index in the superior mesenteric artery at rest and during constrictor stimuli in normal subjects. 816 34

The authors previously reported that mesenteric ischemia and reperfusion (I/R) in a chronic newborn piglet model creates dysfunctional intestinal motility. Whether this leads to inadequate bacterial clearance and translocation (BT) through the gastrointestinal tract remains unclear. To test this hypothesis the authors used their chronic piglet model (weight, 3.5 +/- 0.3 kg; age, 18 +/- 4 days; on formula feeding); nonocclusive mesenteric ischemia was induced via reversible pericardial tamponade. Mesenteric flow (SMA Doppler measurement via the retroperitoneal approach) was decreased to 25% +/- 5% of baseline for 300 minutes in the ischemia group (n = 7) and followed by 14 hours of reperfusion in the I/R group (n = 6). Control subjects had a sham operation (n = 7). Mesenteric lymph nodes (MLN), liver (L), spleen (S), ileum, peritoneum, and blood were harvested for blind quantitative microbial analysis. Subjects in the control group had no cultures positive for growth. Eighty-five percent of animals in the ischemia group had positive MLN cultures only (P < .05 v control). All piglets in the I/R group had positive MLN cultures (P < .05 v control), and one third of them manifested bacteremia. Histological examination did not show mucosal disruption in any group. The validity of this model is confirmed by the negative cultures in the control group and by the presence of normal ileal flora in all animals. In the ischemia and I/R groups, MLN cultures were consistently positive with gram-negative bacilli (Escherichia coli and/or Klebsiella pneumoniae). When subjects of the I/R group had more than 1,000 colonies in the MLN, bacteremia with the translocating organisms was also identified.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bacterial translocation in mesenteric ischemia-reperfusion injury: is dysfunctional motility the link? 817 6

Currently there exists no reliable serum marker for the early diagnosis of acute mesenteric ischemia. We investigated D(-)-lactate as a marker of acute mesenteric ischemia in a rat model. D(-)-Lactate is a byproduct of bacterial metabolism; it is neither produced nor metabolized by mammalian cells. In an ischemic segment of bowel the resident microflora rapidly proliferate and soon overgrow the affected intestinal segment. Additionally, the mucosal barrier of the gut begins to break down. Under these conditions we hypothesize that D(-)-lactate should cross the mucosal barrier in large quantities. To determine if this rapid bacterial proliferation and mucosal leakage produces D(-)-lactate concentrations in quantities sufficient to elevate peripheral blood levels, two models of acute intestinal ischemia and one model of simple obstruction were developed in rats. The three models included: strangulation obstruction of terminal ileum, superior mesenteric artery ligation, and simple intestinal obstruction of the ileum. Controls were divided into two groups: sham-operated controls and unoperated controls. Serum samples were collected via an internal jugular catheter at 5 min, 2 hr, and 4 hr after surgery. These samples were then assayed for D(-)-lactate using an enzymatic-spectrophotometric assay. Data was analyzed by repeated measures analysis of variance and where applicable the Student t test was used to determine statistical significance. We found statistically significant elevations in D(-)-lactate concentrations as early as t = 5 min in the strangulation obstruction model and SMA ligation model compared to unoperated controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Serum D(-)-lactate levels as a predictor of acute intestinal ischemia in a rat model. 836 Nov 76

Duplex ultrasonography accurately identifies high-grade stenoses in the SMA. Analysis of velocity data reveals few false positives and virtually no false negatives in the determination of high-grade SMA stenosis by duplex scanning. We therefore utilize duplex scanning to perform early screening studies of patients with symptoms suggestive of chronic visceral ischemia. If the duplex findings are negative, we recommend evaluating for other sources of abdominal pain. If the findings are positive, prompt angiography is indicated. It is important to remember that although duplex scanning can identify mesenteric artery stenosis, it cannot diagnose intestinal ischemia. By establishing duplex scanning as a useful and accessible noninvasive screening tool, it is hoped that the time between onset of visceral ischemic symptoms and diagnosis of chronic visceral ischemia will be shortened significantly, potentially reducing the morbidity and mortality of the disease.
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PMID:Duplex ultrasonography in evaluation of splanchnic artery stenosis. 914 17

Compression of the visceral arteries can produce true mesenteric ischemia, but the syndrome is rare. The syndrome is caused by unfavorable anatomic relationships at the aortic hiatus among the CA, the SMA, and overlying structures, particularly the diaphragmatic crura. These anatomic relationships, in contrast to the syndrome they sometimes produce, are relatively common, which makes the detection of CA compression only a prerequisite to the diagnosis of the clinical entity. The diagnosis of CA compression syndrome ultimately depends on the relentless elimination of other possible causes for abdominal pain and on the knowledge that this curious syndrome does indeed exist. If properly diagnosed, the CA compression syndrome can be corrected with a safe, relatively simple surgical procedure. Past treatment series reflect too little appreciation for the extensiveness of a true, chronic CA injury. Revascularization of the CA, in addition to release of compression, should therefore be performed with greater frequency in the future. The young patients who are successfully diagnosed and treated for this unusual syndrome are frequently entirely relieved of long-standing, debilitating pain, and, like other patients with chronic mesenteric ischemia, they typically enjoy dramatic improvement in the quality of their lives. Thus, with the prospect of these patients in mind, a clinician should accept the opinion that the syndrome "does not exist" only after careful consideration of the entire literature.
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PMID:Celiac artery compression syndromes. 914 22

Long-term survival of carcinomas in the body and tail of the pancreas after surgery is still rare. One of the major reasons for unresectability is cancerous invasion to major vessels, such as the common hepatic and splenic arteries. Resection of the involved arteries can increase resectability and thus might increase post-operative survival. The aim of this study was to clarify the importance of the Appleby operation for carcinoma of the body and tail of the pancreas. A Case Report was carried out with a 54 year-old man, had suffered back pain and loss of body weight for six months. Imaging procedures such as US, CT or angiography showed a carcinoma in the body of the pancreas, about 3 cm in size, and both the common hepatic and splenic arteries were invaded by the tumor. The Appleby operation was used for this patient, since firstly there was no invasion to the head of the pancreas, secondly neither the proper hepatic artery nor the SMA was involved, thirdly the root of the CA was free of carcinoma, and finally because clear pulsation of the proper hepatic artery could be felt one or two minutes after occlusion of the CHA, which indicated that resection of the CHA would not lead to hepatic ischemia. The postoperative course was uneventful. His appetite recovered well and his body weight increased to the level before the disease. The patient was relieved from back pain and has returned to work 18 months after the operation, although he had a local recurrence eight months after the operation. In addition, eleven cases with carcinoma of the body and tail of the pancreas were used for a literature review. The average survival time after the Appleby operation is 6.6 months, and four patients are still alive. One patient has survived 13 years after the operation. It was concluded that although the prognosis after Appleby procedure is still not satisfactory that this operation can at least offer patients a better quality of life.
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PMID:Appleby operation for carcinoma of the body and tail of the pancreas. 916 7

We examined the biopsy specimens of 62 patients with diabetic nephropathy to establish whether the myofibroblast (MF) has a role in progressive interstitial fibrosis and to ascertain whether a relationship existed between MF activity and severity of arteriolosclerosis. MF were identified by morphology and alpha smooth muscle actin (alpha SMA) immunostaining. Analysis of vascular injury was performed by counting the number of interstitial arterioles after staining endothelial cells with von Willebrand factor (VWF) antibody. Arteriosclerosis was quantified by using a computer-aided image analyzer to measure the arteriolar wall surface and total arteriolar surface area, and the ratio of wall to total surface area was expressed as the index of arteriosclerosis (IA). Fractional area of interstitium (IFA), alpha SMA, and collagen III (Coll III) were quantitated by point counting. Results were related to structural and functional parameters using rank correlation coefficients. There was a strong correlation between IFA and Coll III staining (r = 0.83; P < 0.001). The alpha SMA staining correlated with IFA (r = 0.56; P < 0.001) and Coll III (r = 0.47; P < 0.001), and there were significant correlations between alpha SMA and total urinary protein (r = 0.47; P < 0.001), renal function (plasma creatinine) at time of biopsy (r = 0.51; P < 0.001), and the percent change in plasma creatinine after 4 years (delta Cr) (r = 0.37; P = 0.01). The IA correlated significantly with Coll III (r = 0.29; P = 0.02), glomerular filtration rate (GFR) (r = 0.39; P = 0.008), and creatinine (r = 0.33; P = 0.01), but no correlation was observed between alpha SMA and IA (r = 0.16; P = 0.23) or IA and delta Cr (r = -0.04; P = 0.6). Strong correlations could be shown between arteriolar density, IFA (r = 0.75; P < 0.001), alpha SMA (r = -0.36; P = 0.034), and Coll III (r = -0.66; P < 0.0001). The MF appears to have a significant role in the progression of diabetic nephropathy. Ischemia secondary to arteriosclerosis may contribute to interstitial fibrosis through fibroblast modulation into MF.
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PMID:Myofibroblasts and arteriolar sclerosis in human diabetic nephropathy. 918 78

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a potent fibroblast and epithelial cell mitogen that may be important in wound healing. The aim of this study was to determine its distribution and possible function in segmental renal infarction. At day 1 postinfarction, in situ hybridization showed that HB-EGF mRNA was markedly increased by tubular epithelial cells bordering the infarcted zone. At day 3, typical myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA) were present in large numbers at the peri-ischemic border and, over succeeding days, were also seen within the infarcted area. Some of these cells expressed HB-EGF mRNA by in situ hybridization suggesting possible autocrine stimulation. Endothelial cells appeared to be more resistant to ischemia than tubules because some capillaries at the periphery of the infarct, surrounded by infarcted tubules, also expressed HB-EGF mRNA. The staining intensity of HB-EGF mRNA in individual tubules and endothelial cells was maximal at day 5 after infarction, although Northern blots of tissue from the peri-infarct area only showed significantly increased expression of HB-EGF mRNA at days 1 and 3, perhaps reflecting a smaller area of greater intensity of expression at day 5. Because tubular cells expressing high levels of HB-EGF mRNA were directly apposed to myofibroblasts, an attempt was made to determine whether HB-EGF contributed to upregulation of alpha-SMA by human fibroblasts. Although stimulation of the fibroblast cell line MRC-5 with transforming growth factor-beta1 (TGF-beta1) increased alpha-SMA, HB-EGF reduced expression. HB-EGF also strongly inhibited the increased expression of alpha-SMA due to TGF-beta1. Because HB-EGF is a potent fibroblast mitogen and TGF-beta is usually antiproliferative, this study suggests that HB-EGF may contribute to a local balance between fibroblast proliferation and differentiation into myofibroblasts during scarring.
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PMID:Heparin-binding EGF-like growth factor mRNA is upregulated in the peri-infarct region of the remnant kidney model: in vitro evidence suggests a regulatory role in myofibroblast transformation. 969 69


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