SEARCH · PubMed Health

Results for “MESENTERY”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources

PubMed1996

[Leiomyosarcoma of the mesentery. A case report and clinico-diagnostic considerations].

Leiomyosarcoma of the mesentery is a rare neoplasm. The clinical manifestation is non-specific and preoperative diagnosis is often late. Mitotic activity shows no significant correlation with the biological behavior of neoplasm. The surgical excision is the therapy of choice but local recurrence is high. The authors report a case of leiomyosarcoma which was treated by surgical removal and underline the diagnostic difficulties.

Aged↗

PubMed1977

Mesenchymal solid tumors of the omentum and mesentery: report of four cases.

Attention is drawn to the solitary solid tumors originating in the intra-abdominal mesenteries and in the omentum. These are rare lesions, each associated with an insidious onset and with a laterally ballotable mass frequently representing the only expression of disorder clinically. Some mesenchymal lesions have long eluded the pathologist and the surgeon in the frustration of firmly categorizing the predominant cellular involvement. At times there is an area of "spill-over" or of mixed tumor elements within the same lesion. Occasionally the lesion type is defined eventually only by recurrence and/or a lethal outcome attributable to tumor spread, regardless of its original cellular features. The management of four patients, two with omental tumors (leiomyoblastoma) and two with tumors of mesenteric origin (one patient with fibromatosis and the other with leiomyosarcoma), is presented from the 15 year experience of a large hospital facility. The uncomplicated diagnostic investigations are stressed as well as the essentiality of wide surgical resection to fully elaborate all morphologic features and to thwart recurrent disease in the future.

Adult↗

PubMedDate not supplied

Protein exudation induced by manipulation of the intestines and mesentery during laparotomy in rat. A study of the mechanism of 'third space' loss.

BACKGROUND-MATERIALS: Much extracellular fluid administration is required during major surgery because of the functional loss of extracellular fluid. In the present study we investigated the effect of manipulation of the intestines and mesentery in a rat laparotomy model. METHODS-RESULTS-CONCLUSIONS: The results showed that manipulation significantly increased the amount of protein exudated into the peritoneal space and induced a marked histopathological inflammatory response including polymorphonuclear leukocyte infiltration and mast cell degradation. These findings suggest that the inflammatory response induced by manipulation may, at least in part, explain the underlying mechanism of 'third space' loss during abdominal intestinal surgery.

Animals↗

PubMed1976

Lipogranulomatosis of the mesentery.

This paper describes a 21-year-old man with lipogranulomatosis of the mesentery. This condition is characterized by a non-specific inflammatory process of the adipose tissue in the radix mesenterii. So far as could be established, this is the first patient in whom vascular anomalies and displacement of lymphatic vessels and lymph nodes have been described. However, these changes are hardly specific so that definite conformation of the diagnosis must be obtained by a biopsy. The aetiology is unknown. There is no established therapy for this benign, self-limiting disease.

Adult↗

PubMed1976

[Character of changes in the microcirculatory bed of the mesentery of the small intestine in experimental acute myocardial infarct].

On the first day of the development of acute coronary insufficiency there appears a spastic state of all the vascular system of the small intestine mesentery and a deceleration of the blood flow. On the third day after ligation of the coronary artery branch against the background of spasmed arterioles the alternation of sites of constricted and dilated capillaries, postcapillaries and venules was observed, i.e., there was a well pronounced spasticatonical state of the microcirculation bed vessels. On the fifth and seventh day the characteristic features were dilatation and decreased tonus of the venous part of the microcirculatory bed, redistribution of blood and more considerable disorders in microcirculation with aggregation and diapedesis of erythrocytes.

Acute Disease↗

PubMed1975

Abdominal cystic lymphangiomatosis: report of a case involving the liver and spleen and illustration of two cases with origin in the greater omentum and root of the mesentery.

B-scan ultrasonic examination of a 10-year-old Mexican-American female with multiple avascular hepatic and splenic defects on both isotopic and angiographic evaluation revealed numerous cystic lesions, a few of which contained numerous internal echoes. Subsequent pathological examination revealed lymphangiomatosis of the liver and spleen. Some of the cysts contained caseous material as predicted only by the ultrasonic examination. Cystic lymphangiomatosis of the spleen is a rare condition and only a few cases of involvement of both the spleen and liver have reported. This is the first such case evaluated by ultrasound. Two cases are also illustrated of cystic lymphangiomatosis with origin in the greater omentum and root of the mesentery.

Adolescent↗

PubMed1993

Characterization of [3H]ryanodine binding sites in smooth muscle of dog mesentery artery.

The ryanodine receptor has been widely demonstrated to be a Ca2+ release channel in both skeletal and cardiac muscle. Ryanodine also functionally affects Ca2+ release from an intracellular pool of smooth muscle. In the present study, both high and low affinity ryanodine binding sites are identified in dog mesenteric artery (with Kd 5 nM and 269 nM, respectively). [3H]ryanodine binding is not correlated with the density of innervation in different smooth muscles. This study provides direct evidence of the presence of ryanodine binding sites in dog mesentery artery. These ryanodine binding sites are of smooth muscle origin.

Animals↗

PubMed2001

Role of shear and leukocyte adherence on venular permeability in the rat mesentery.

The role of fluid shear stress on permeability has been controversial. In vitro studies have shown higher endothelial permeability with an increase in shear, but in vivo higher shear can also decrease permeability by attenuating leukocyte adherence (e.g., during an inflammatory response). The potential contribution of fluid shear and leukocyte adherence acting simultaneously to determine basal levels of permeability remains unresolved. Therefore, the purpose of this study was to understand the effects of basal shear and leukocyte adherence on venular permeability of the rat mesentery. Using a modification of current measurement techniques, we were able to quantify permeability under physiological flow and estimate its convective and diffusive components. We found that water filtration plays a minor role in the transport of albumin across venular endothelium, that permeability exhibits a moderately linear correlation with shear, and that the number of leukocytes adherent to the endothelium accounts for the majority of the scatter in this correlation. Multiple regression analysis of permeability as a function of shear rate and leukocyte adherence revealed significant roles for both factors (regression P < 0.01, r2 = 73.9%).

Animals↗

PubMed1987

The anti-oestrogen tamoxifen is a calcium antagonist in perfused rat mesentery.

The anti-oestrogen tamoxifen in the range 10(-7)-10(-5) M induced concentration-related inhibition of potassium-stimulated vasospasm in the isolated perfused rat mesentery vascular bed. In contrast, responses to noradrenaline did not fall below control levels until the tamoxifen concentration exceeded 4 X 10(-6) M. Recovery of the potassium-stimulated responses was also concentration-related. The most likely explanation is that while tamoxifen can obstruct the entry of extracellular calcium, it is unable to prevent the intracellular release of the ion by noradrenaline.

Animals↗

PubMed2003

Fine structure and mineral components of fibrous stonelike masses obtained from the human mesenteries.

We investigated the fine structure and mineral components of 29 stonelike masses obtained from the mesenteries of four adult cadavers, using optical microscopy, backscattered electron imaging, scanning electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction. Although the overall appearance of the stonelike masses measuring about 5-20 mm in diameter and 0.06-3.1 g in dry weight was roughly grouped into smooth bulb- and uneven bulk-shaped types, all the calcified masses basically consisted of core and mantle regions. The smooth bulb-shaped masses had a broad mantle with many concentric rings, whereas the uneven bulk-shaped masses contained a large core. In their core regions, spherulitic and short bundle-shaped deposits composed of needle-shaped apatite crystals were mainly found among loose collagen fibers. Their mantle regions, on the other hand, showed the concentric structures of dense collagen fibers in the intra- and/or extrafibrous calcification with fine sandy grain-shaped deposits. The mineral elements were mainly Ca and P, and the major crystals were hydroxyapatite. Hexahedral whitlockite containing Mg was a minor component. The fiber-rich mantle regions showed lower calcification and lesser crystallization than the fiber-poor core region. When necrotic or some tumor adipose tissues and necrotic lymphoid tissues that might have been caused by some digestive diseases are recognized as foreign matter, their tissues occasionally will be calcified and grow into stonelike masses. These stonelike masses tend to occur more often in women than in men.

Calcification, Physiologic↗

PubMed2004

Haemangiopericytoma of the sigmoid mesentery.

Haemangiopericytoma is a rare, vascular soft tissue tumour originating from the pericytes surrounding capillaries. We report a case of haemangiopericytoma in the sigmoid mesocolon and are aware of only one previously case. A 61-year-old man was referred with a left iliac fossa mass. At operation, a 10-cm diameter mass was found to be arising from the sigmoid mesentery (Fig. 1). The mass did not involve the bowel wall and there was no clinical evidence of metastatic disease. A sigmoid colectomy with primary anastomosis was performed. The patient made an uneventful recovery. Pathological assessment of the specimen revealed a 95 x 70 x 50 mm(3), purple, lobulated mass within the sigmoid mesocolon adjacent to the bowel. Immunohistological analysis (positive CD34, focal factor VIII) was consistent with a diagnosis of a haemangiopericytoma. Complete excision with adequate margins remains the treatment of choice. We therefore suggest that patients be carefully followed for long periods and advised of the risk of long-term relapse.

Colectomy↗

PubMed1990

Vasodilator effects of sarafotoxins and endothelin-1 in spontaneously hypertensive rats and rat isolated perfused mesentery.

Sarafotoxins (SRTa, SRTb and SRTc) and ET-1 produced a potent vasodilator effect in spontaneously hypertensive rats in vivo and in rat isolated perfused mesenteries in vitro. Among these peptides SRTc demonstrated the most potent vasodilator activity, and was three times more active than SRTa in both preparations. These peptides induced endothelium-dependent vasodilatation in vitro and pretreatment with methylene blue inhibited this effect, while exposure to the antagonists of other vasodilators did not. In contrast, [nitrophenylsulfenylated Trp21]SRTc, SRTc(1-18) and reduced and S-carboxymethylated SRTc caused no vasodilatation in either animal model; the vasodilator effect of acetylated SRTc was less potent than that of SRTc. These results suggest that (i) the vasodilatations of these peptides may be exerted through the release of endothelium derived relaxing factor; (ii) the C-terminal Trp21 and disulfide bonds are essential; and (iii) the N-terminal amino group plays an important role in vasodilator activity.

Amino Acid Sequence↗

PubMed1985

Activation of the hypothalamo-neurohypophysial system by hypertonic superfusion of the rat mesentery.

Well-defined areas of the mesentery were superfused during 3 s with 300 microliters of hypertonic NaCl solution, while monitoring the electrophysiological response of the hypothalamo-neurohypophysial tract. Response magnitudes were largest for superfusion of the portal, the duodenal and jejunal mesenteric veins, and least for superfusion of the mesenteric vessels of the ileum. The results suggest the existence of peripheral receptors that appear to be strategically located to monitor the intestinal absorption of salt or water.

Animals↗

PubMed1986

An isolated perfused rat mesentery model for direct observation of the vasculature during cryopreservation.

An intact vasculature is essential for successful hypothermic perfusion and cryopreservation of solid organs, but few studies have specifically assessed the vascular effects of these procedures. A technique was therefore developed for continuous, direct observation of an isolated vascular bed during hypothermic perfusion with cryoprotectants, and during freezing and thawing. The isolated rat mesentery was spread across a controlled low temperature microscope stage and perfused with solutions containing fluorescein isothiocyanate (FITC)-Dextran 70 as an indicator of macromolecular permeability of the vessels. Hypertonic citrate washout, HP-5 perfusion (23), rapid and slow addition and removal of glycerol, and freezing/thawing were studied. Control perfusion with HP-5 produced slow FITC-Dextran leakage, reflecting normal physiological macromolecular permeability of vessels. Rapid addition of glycerol dramatically increased vascular permeability, consistent with osmotic damage to vessels. Rapid removal stopped flow through capillaries and decreased vascular dimensions, suggesting overhydration of endothelial cells and extravascular tissue. Venules and capillaries were the most susceptible vessels to osmotic stress. Slow addition and removal of glycerol (80 mmol/liter/min) produced results similar to control perfusions. During slow freezing (0.5 degree C/min to -5 degrees C) extravascular ice compressing vessels was more obvious than intravascular ice. Glycerol afforded some protection to the microvasculature during freeze/thaw cycles since flow was reestablished in venules and arterioles after thawing, although FITC-Dextran leakage indicated that damage had occurred.

Animals↗

PubMed1991

Differential effects of neuropeptide Y and opioids on neurogenic responses of the perfused rat mesentery.

In perfused rat mesentery transmural nerve stimulation activates both adrenergic and capsaicin-sensitive sensory nerves. When adrenergic nerves were blocked with guanethidine and smooth muscle tone was increased, transmural nerve stimulation caused a dilator response which was attenuated by tetrodotoxin and abolished by capsaicin. Indomethacin increased the vasodilator response to transmural nerve stimulation, but did not affect the dilation to calcitonin gene-related peptide. Neuropeptide Y (NPY) potentiated vasoconstrictor responses to transmural nerve stimulation, but suppressed capsaicin-sensitive vasodilation, an effect which was unaltered by indomethacin. Opioid agonists selective for mu, delta or kappa receptors, DAMGO ([D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin), DPDPE ([D-Pen2,D-Pen5]enkephalin) and ethylketocyclazocine, had no effect on the vasoconstrictor response to transmural nerve stimulation. DAMGO and DPDPE significantly inhibited vasodilator responses to transmural nerve stimulation, but ethylketocyclazocine was without effect. After treatment with indomethacin, DAMGO still inhibited the vasodilator response, but DPDPE was no longer effective. Prejunctional control of transmitter release by NPY or opioids is dependent on the specific nerve type as well as, in some cases, the participation of endogenous prostaglandins.

Animals↗

PubMed1991

Effect of opioid receptor antagonists on vasodilator nerve actions in the perfused rat mesentery.

Our previous work suggests that opioid peptides modulate sensory nerves in the perfused rat mesentery. Therefore we tested the hypothesis that opioids are involved in the ongoing regulation of sensory nerve activity using selective opioid receptor antagonists. In the presence of guanethidine and methoxamine, transmural nerve stimulation caused a vasodilator response which was potentiated significantly by naloxone (3 x 10(-7) M). However, naloxone did not affect vasodilator responses to exogenous calcitonin gene related peptide. IC1 174.864 (3 x 10(-7) M), a selective delta receptor antagonist, had no effect on vasodilator responses to transmural nerve stimulation. In contrast CTOP (D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Phe-Thr-NH2) (3 x 10(-7) M), a selective mu receptor antagonist, significantly inhibited vasodilator responses to transmural nerve stimulation, effects which were abolished by naloxone treatment. In preparations pretreated with beta-FNA (beta-funaltrexamine HCl), an irreversible mu receptor antagonist, naloxone no longer potentiated vasodilator responses to transmural nerve stimulation. These results suggest that potentiation of vasodilator responses to transmural nerve stimulation by naloxone may be due to blockade of mu receptors, resulting in a reduced inhibitory modulation by endogenous opioids. These findings support the contention that prejunctional opioid receptors on sensory nerves may play a role in modulating activity of the cardiovascular system.

Animals↗

PubMed1993

Mechanisms of endothelin-induced macromolecular leakage in microvascular beds of rat mesentery.

Microvascular responses to endothelin-3 were investigated in the rat mesentery under fluorescence microscopy. Endothelin-3 in a range of 0.1-100 pM induced arteriolar constriction in a dose-dependent manner, and stimulated Ca2+ mobilization, demonstrated by fura-2-associated fluorography, in both arterioles and venules. Cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu-) (BQ123), and endothelin ETA receptor antagonist, at a concentration of 10 microM inhibited the endothelin-3 (100 pM)-induced arteriolar constriction and Ca2+ mobilization in arterioles but not in venules. In venules, an early onset leakage of FITC (fluorescein isothiocyanate)-labeled albumin and subsequent reduction of red blood cell velocity without arteriolar constriction were observed after the superfusion of endothelin-3 with BQ123, suggesting that a non-endothelin ETA receptor mediates macromolecular leakage followed by a decrease in blood flow. Endothelin-3 with BQ123 neither stimulated leukocyte adhesion nor activated luminol-dependent chemiluminescence in venules, showing that endothelin-3-increased permeability may be induced by leukocyte-independent and oxyradical-independent mechanisms. These microvascular alterations of permeability and red blood cell velocity were significantly attenuated by the addition of phalloidin, an F-actin stabilizer, suggesting the involvement of endothelial cell contraction. Nicardipine (1,4-dihydro-2,6-dimethyl-4-[3-nitrophenyl]methyl-2- [methyl(phenylmethyl)amino]-3,5-pyridinedicarboxylic acid ethyl ester), a dihydropyridine-type Ca2+ channel antagonist, eliminated endothelin-3-induced arteriolar constriction; however, it did not affect albumin leakage promoted by endothelin-3 with BQ123, suggesting that a non-voltage-dependent Ca2+ channel(s) is involved in non-endothelin ETA receptor-mediated Ca2+ mobilization and contraction of venular endothelial cells. Overall, it is conceivable that endothelin ETA receptor and voltage-dependent Ca2+ channel are involved in endothelin-3-induced arteriolar constriction. In addition, the present results suggest that Ca2+ mobilization in venular endothelium, which is mediated by a non-endothelin ETA receptor, possibly endothelin ETB receptor and regulated by non-voltage-dependent Ca2+ channel(s), may cause endothelial cell contraction and subsequently increase macromolecular permeability in microvascular beds treated with endothelin-3.

Amino Acid Sequence↗

PubMed1994

Flow dynamics of erythrocytes in microvessels of isolated rabbit mesentery: cell-free layer and flow resistance.

A part of microvascular bed isolated from rabbit mesentery (composed of a few branches of superior mesenteric artery) was used for the study of the flow dynamics of erythrocytes in microvessels. The flow resistance in the microvascular bed was analyzed with respect to the thickness of a cell-free layer formed along the inner wall of vessels and the suspension viscosity of erythrocytes (in terms of hematocrit and erythrocyte deformability). The thickness of the cell-free layer increased with the increase in the inner diameter of microvessels. By lowering the hematocrit, the thickness increased and the flow resistance decreased. Meanwhile, by decreasing the erythrocyte deformability with diamide, the thickness decreased and the flow resistance increased. However, the thickness was not altered in microvessels less than 10 microns by the diamide treatment. The maximum inner diameter of microvessel required to induce parachute- and/or slipper-like deformation (at flow velocity of erythrocytes less than 2 mm s-1) was 13 microns for control cells and 6 microns for diamide-treated cells. The thickness of the cell-free layer could not be closely related to the flow resistance, while a good relationship applicable to both control and diamide-treated cells was obtained between the flow resistance and the suspension viscosity. The present results conclude that the flow resistance in the isolated microvascular bed is mainly provided by both hematocrit and erythrocyte deformability.

Animals↗