Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MESENTERY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 217 records · Page 12Linked to original sources

The control of macro- and microcirculation in the mesentery and intestine.

The total blood flow and microvessel blood flow in the mesentery and the intestine anesthetized rabbits were measured while systemic hemodynamics were altered by baroreceptor stimulation and by noradrenaline injection. The percent change of the total peripheral resistance (Rt) was greater than the change in resistance in the intestinal vascular bed (Ri) during baroreceptor stimulation. The capillary blood flow in the intestinal muscle layer (Qs) and villus (Qv) increased slightly while the intestinal arterial flow (Qa) and the arteriolar flow in the mesentery (Qm) decreased. These data indicated that Qs and Qv were not controlled by the sympathetic vasoconstrictor system. The percent change of Ri was greater than that of Rt during noradrenaline injection. Noradrenaline decreased Qa, but Qs and Qv were decreased while Qm was increased. These results show that noradrenaline stimulates alpha-adrenoceptors on small arteries and arterioles in the intestine. The observed Qm changed was in response to the systemic hemodynamic change caused either by the baroreceptor input or by noradrenaline.

Animals↗

Macro- and microcirculatory effects of tetramethylpyrazine and extract of Charthamus tinctorius L. in rabbit mesentery.

Effects of tetramethylpyrazine (TMP) and that of extracts of Charthamus tinctorius L. (CTL) on the macro- and microcirculation in rabbit mesentery were studied. The intestinal arterial blood flow (Qa) was measured using an electromagnetic flowmeter, together with the arterial blood pressure (Pa). The inner diameter and red cell velocity in single arteriole in the mesentery were measured by a video-image technique and a dual-slit photometric method, respectively. Using the measured diameter and red cell velocity, the arteriolar blood flow (Qm) was calculated. Both the Qa and Qm decreased when Pa was decreased after the intravenous administration of TMP, CTL, Nicardipine, Phentolamine and acetylcholine (Ach). Changes in Qa and Qm with changes in Pa were analyzed, and it was found that (i) both the Pa-Qa and Pa-Qm curves, during the administration of TMP or CTL, show different patterns from those during the administration of Nicardipine or Phentolamine; (ii) the Pa-Qa and Pa-Qm curves after the administration of TMP or CTL show similar patterns with those after the administration of Ach.

Acetylcholine↗

[Primary venous mesenterial thrombosis in three patients].

Three patients, a woman aged 72, a man aged 25 and a woman aged 42 years, presented at the casualty department with a subacute form of primary venous mesenterial thrombosis. As symptoms and laboratory findings are aspecific, CT scan is the gold standard for the diagnosis of this condition. In these patients no cause or predisposing factor was detected, so the disease was considered to be primary. Treatment generally consists of anticoagulant therapy and if peritonitis is present operation is indicated. Hyperdynamic circulation and inotropica are indicated after surgery and in cases of critical illness. Based on clinical findings the third patient was treated successfully with anticoagulants only. The other two also underwent partial small intestinal resection. All three patients were discharged in good health and were prescribed lifelong anticoagulants. If a cause of venous mesenterial thrombosis can be found, this must first be treated before deciding on whether lifelong treatment with anticoagulants is indicated.

Adult↗

Inhibition effect of cardiotonic pills on venous thrombosis induced in rat mesentery by photochemical reaction.

This paper was aimed to explore the inhibition effect of cardiotonic pills (CP) on venous thrombosis induced in rat mesentery by photochemical stimulation (PS). Male Sprague-Dawley rats were anesthetized with urethane. Thrombosis was induced in the mesenteric venule by PS with photosensitizer hematoporphyrin and an ultraviolet beam. The rats were divided into three groups: control (n = 6), PS (n = 6) and PS + CP group (n = 6) where CP solution (0.4 g/kg.b) was administrated orally 60 min before PS. Microcirculatory disturbances in the mesentery were observed under an inverted microscope with a color video-camera. Based on the recorded images, the development of thrombosis was evaluated in term of time of thrombosis appearance (T(a)) and area ratio of thrombus/vessel (AR). The expression of adhesion molecule (CD31) of platelet was examined in blood taken from the abdominal aorta, using flow cytometry. The T(a) was approximately 10 seconds after PS in PS group, but it was approximately 20 seconds in PS + CP group. The AR in PS + CP group was significantly reduced, compared to that in PS group, during the period of the observation. The CD31 expression was not changed in both groups, while positive cells were significantly increased in the number. It is suggested that CP might suppress thrombus development under the interaction of platelet with endothelium.

Animals↗

Capillary growth in the mesentery of normal young rats. Intravital video and electron microscope analyses.

Capillary sprouting was studied by a combination of intravital video recording and subsequent electron microscopy in the mesentery of young female rats without previous experimental manipulation. Selected segments of the mesenteric microvascular bed with capillary sprouts were carefully surveyed and mapped at a monitor magnification of 255 times and submitted to detailed in vivo analysis concerning flow pattern and cells at 2000 times magnification. The mesentery was preserved for light and electron microscopy by a superfusion of glutaraldehyde while observed and recorded on video, confirming earlier investigations that this type of fixation does preserve exceptionally well vascular topography and diameters of the mesenteric microvascular bed. Capillary sprouts originated as endothelial spurs from arteriolar-venular arcades and continued to grow in size through a bipolar rearrangement of endothelial cells, forming a solid sprout tip which progressively lengthened by alternately rapid and slow growth phases. The extended leading tip of the migrating endothelial cells displayed microspikes and pseudopodia denuded of basal lamina. The cytoplasm of the leading tip contained an array of microtubules, 75 A filaments and many small vesicles. In similarity with the situation in nerve growth cones, all these organelles probably participate in cytoplasmic streaming and cell migration. The sprout lumen arose between endothelial cells of the solid sprout. Mesenteric connective tissue fibroblasts approached and settled down on the sprouts, being converted to pericytes as the fibroblasts became enveloped by a basal lamina. The pericytes reinforced the wall of the delicate and fragile capillary sprouts, and trapped plasma, platelets and red blood cells which had leaked out temporarily, in the process assuming an umbrella shape. The arteriolar feeder of the arcades was surrounded by cells which were classified as intermediate between pericytes and true smooth muscle cells. Sprouts that presumably were on the verge of merging with other capillaries were analyzed for indications of how anastomoses are formed.

Animals↗

Malignant lymphoma of the gastrointestinal tract and mesentery. A clinico-pathologic study of the significance of histologic classification. NHL Study Group of the Comprehensive Cancer Center West.

A series of 92 malignant lymphomas of the gastrointestinal tract and mesentery obtained from a population-based registry was studied to assess whether the newly defined concept of mucosa-associated lymphoma has clinical relevance. The cases were grouped according to localization; gastric, intestinal, and mesenteric lymphoma. All cases were reviewed histologically, graded according to the Working Formulation, and reclassified according to the Kiel classification, which was modified to include the categories low- and high-grade mucosa-associated lymphoma. Clinical data, as well as staging and follow-up data, were related to both the original diagnosis and the diagnosis after reclassification. The results showed that the distribution of the types of lymphoma is related to site: centroblastic lymphoma was predominant in the stomach, lymphoblastic in the bowel, and follicular centroblastic-centrocytic in the mesentery. Gastrointestinal lymphoma was disseminated in approximately 50% of the patients at presentation. Survival analysis revealed that classification according to the original Kiel classification and grading according to the Working Formulation provided important prognostic information, whereas introduction of mucosa-associated lymphoma as an entity did not. It was concluded that modification of current classifications to include a separate category for mucosa-associated lymphoma is not useful.

Gastrointestinal Neoplasms↗

Immune histochemical and electron microscopic observations on so-called non-specific mesenterial lymphadenitis.

Two cases of so-called mesenterial lymphadenitis in childhood were investigated with the immunoperoxidase technique. One more case was studied electron microscopically. All three cases were morphologically identical. In two cases infection with Yersinia enterocolitica was proven serologically. The majority of the lymphoid cells which filled the strongly distended sinuses represented electron microscopically various steps of the lymphocyte transformation. Immune histochemically, the blasts contained large amounts of immunoglobulins. It is suggested that the mitogen and adjuvant activity of bacterial lipopolysaccharides may substantially be involved in the pathogenesis of the characteristic lesion of the mesenterial lymphadenitis.

B-Lymphocytes↗

Potentiation of histamine-induced microvascular permeability by prostaglandin E2 in rat mesentery.

The effect of prostaglandin E2 and histamine and their interaction on microvascular permeability in the rat mesentery was examined using fluorescent in vivo microscopy. Leak of a fluorescein-albumin conjugate from microvessels was determined 3 min after the topical application of prostaglandin E2 and/or histamine. The size of the leak (micron 2) was quantitated using a grid over the face of the videomonitor. To determine the role of endogenous prostaglandin, some rats were pretreated with 10 mg kg-1 indomethacin intravenously. All studies were performed coded. Dose-response studies performed with either prostaglandin E2 or histamine alone revealed that each agent increased microvascular permeability in a dose-related fashion. On a molar basis, prostaglandin E2 was more potent than histamine in this regard. When a low dose of prostaglandin E2 was administered together with a low or intermediate dose of histamine, the size of the resulting leak was significantly greater than the sum of the size of leak produced by each agent given separately. When rats were pretreated with 10 mg kg-1 indomethacin intravenously to inhibit prostaglandin synthesis, the histamine dose response was shifted to the right. From these experiments, we conclude that: In the rat mesentery, both topical prostaglandin E2 and histamine increase microvascular permeability to macromolecules in a dose-related fashion. Prostaglandin E2 is significantly more potent than histamine in this regard. Both exogenous and endogenous prostaglandin potentiate histamine's effect on microvascular permeability.

Animals↗

The effect of dopamine, apomorphine and piribedil on the mesenterial blood flow of the cat.

Responses to i.v. administration of dopamine, apomorphine, piribedil and bromocriptine were investigated in the feline mesenteric vascular bed. Dopamine increases the mesenterial flow in doses of 0.3 to 30 micrograms/kg; its effect can be inhibited by 1 to 3 mg/kg of sulpiride. Apomorphine and piribedil also increased the blood flow, but only in 20 to 200 times higher doses; they show a tachyphylaxis phenomenon and their maximal activity is 32 and 59 per cent, respectively, that of dopamine. Apomorphine is a partial agonist of dopamine and can inhibit the activity of the transmitter amine. Bromocriptine has no activity on the feline mesenterial flow. The postsynaptic dopamine receptors of the cat can be characterized by the following: strong efficacy of dopamine and lower ones of apomorphine, piribedil and of sulpiride. The presynaptic dopamine receptors are involved mostly in the hypotension, they are activated by low doses of apomorphine, and piribedil and by higher doses of dopamine; sulpiride reacts with these receptors in much lower doses than with the postsynaptic ones.

Animals↗

[Microcirculatory changes in the mesentery and skeletal muscle of the rat in relation to systemic arterial pressure during stimulation of the hypothalamic nuclei].

In acute experiments on anesthetized rats, hypothalamus sites were stimulated through bipolar electrodes. Vasomotor reactions and blood flow in mesenteric and spinotrapezius muscle vessels were studied and recorded by intravital microscopy and microphotography. Systemic blood pressure (BP) was measured in the carotid artery via a catheter. The results indicate that electric stimulation of different hypothalamus sites induces pressor, depressor or biphasic BP reactions that are related to the site stimulated. Microcirculatory changes were monotonous. Regardless of BP reaction in the microcirculatory network of the mesentery, the transient acceleration, slowdown and stoppage of the blood flow were observed in mesenteric microvessels (10--70 micrometer) without changes in their diameter. Pronounced constriction of the diameter of small arteries (90--250 micrometer) were also recorded in the mesentery. During BP pressor reaction the dilatation of microvessels (5--40 micrometer) of the skeletal muscle and an increase in their blood content were noted.

Animals↗

E-selectin mediates leukocyte rolling in interleukin-1-treated rabbit mesentery venules.

The selectins are lectin-like cell surface glycoproteins that have been implicated in playing a crucial role in the initiation of leukocyte adhesion to endothelial cells (ECs) during inflammation. Binding of selectins under conditions of flow mediates leukocyte rolling, which in vivo is almost exclusively observed in venular microvessels. We have shown in previous experiments that intraperitoneal treatment of rabbits with interleukin-1 beta (IL-1) increases leukocyte rolling in exteriorized mesenteries. In the present study, we used immunohistochemistry of mesenteries and found that IL-1 induced a marked E-selectin immunoreactivity, preferentially in venules. We therefore hypothesized that the increased rolling in response to IL-1 may be related to the induction of E-selectin on venular ECs. Intravital microscopy was used to investigate interactions between leukocytes and ECs after intraperitoneal application of IL-1. The rabbit E-selectin monoclonal antibody (MoAb) 9H9 significantly reduced rolling of leukocytes by approximately 40%. Vehicle alone, class-matched control MoAb or the nonblocking anti-E-selectin MoAb 14G2 had no effect on rolling. These results indicate that leukocytes roll on inflamed venular ECs partly through interactions with E-selectin. Furthermore, we propose that the restricted E-selectin immunoreactivity by venular ECs contributes to the remarkable difference seen between arterioles and venules in exhibiting leukocyte rolling in vivo.

Animals↗

Metastatic melanoma of mesentery.

A case of malignant melanoma metastatic to small bowel mesentery in an old female is reported. Her primary malignant melanoma of nasal mucosa was already treated. She presented with intestinal obstruction, underwent surgical excision of the tumour and was tumour-free postoperatively.

Aged↗

Heterotopic ossification within the small-bowel mesentery.

Heterotopic bone formation has been previously noted in abdominal laparotomy scars, but the presence of ectopic bone within the peritoneum is extremely rare. Our patient had recurrent formation of heterotopic bone involving the abdominal wall, peritoneum, and small-bowel mesentery. The features of various types of ectopic calcification are discussed, and several theories concerning the pathogenesis and treatment of heterotopic ossification are examined.

Abdominal Muscles↗

Castleman's disease of the mesentery in a child: a case of seven years' duration without typical X-ray findings.

This report describes a 9-year-old boy with intermediate variant type of giant lymph node hyperplasia or Castleman's disease (CD) originating from the mesentery. He had symptoms and signs related to the disease for seven years before the final diagnosis. The patient's general condition remained good, except for periods of fever and abdominal pain. Pallor and slow growth were the only abnormal findings on physical examination during the follow-up. Laboratory measurements showed worsening microcytic anemia, low serum iron level, and low iron stores in bone marrow samples. The erythrocyte sedimentation rate (ESR) increased to 110 mm/h, and the serum levels of C-reactive protein varied between 80 and 120 mg/l. The level of serum albumin was low, 25-28 g/l, and serum immunoglobulin G was somewhat elevated, varying between 17-13 g/l. The radiologic examination of intenstine gave pathological results suggesting a small bowel disease, but no tumor was detected. The abnormal laboratory values and symptoms of the patient resolved completely after surgical removal of the mass.

Castleman Disease↗

Color Doppler findings in Castleman's disease of the mesentery.

Castleman's disease is a relatively rare lymphoproliferative disease. We report an asymptomatic case of Castleman's disease isolated to the mesentery and detected incidentally by sonography. In this case, color Doppler sonography demonstrated an artery penetrating the mass's hilum, suggesting a lymphatic origin of the lesion, as well as fine accessory peripheral arteries, suggesting malignancy. To our knowledge, there has been no previous report of detailed color Doppler findings in Castleman's disease.

Aged↗

Ectopic bone formation by marrow stromal osteoblast transplantation using poly(DL-lactic-co-glycolic acid) foams implanted into the rat mesentery.

Porous biodegradable poly(DL-lactic-co-glycolic acid) foams were seeded with rat marrow stromal cells and implanted into the rat mesentery to investigate in vivo bone formation at an ectopic site. Cells were seeded at a density of 6.83 x 10(5) cells/cm2 onto polymer foams having pore sizes ranging from either 150 to 300 to 710 microns and cultured for 7 days in vitro prior to implantation. The polymer/cell constructs were harvested after 1, 7, 28, or 49 days in vivo and processed for histology and gel permeation chromatography. Visual observation of hematoxylin and eosin-stained sections and von Kossa-stained sections revealed the formation of mineralized bonelike tissue in the constructs within 7 days postimplantation. Ingrowth of vascular tissue was also found adjacent to the islands of bone, supplying the necessary metabolic requirements to the newly formed tissue. Mineralization and bone tissue formation were investigated by histomorphometry. The average penetration depth of mineralized tissue in the construct ranged from 190 +/- 50 microns for foams with 500-710-microns pores to 370 +/- 160 microns for foams with 150-300-microns pores after 49 days in vivo. The mineralized bone volume per surface area and total bone volume per surface area had maximal values of 0.28 +/- 0.21 mm (500-710-microns pore size, day 28) and 0.038 +/- 0.024 mm (150-300-microns, day 28), respectively. As much as 11% of the foam volume penetrated by bone tissue was filled with mineralized tissue. No significant trends over time were observed for any of the measured values (penetration depth, bone volume/surface area, or percent mineralized bone volume). These results suggest the feasibility of bone formation by osteoblast transplantation in an orthotopic site where not only bone formation from transplanted cells but also ingrowth from adjacent bone may occur.

Animals↗

Autoimmune hemolytic anemia and dermoid cyst of the mesentery. A case report.

An autoimmune hemolytic anemia has been detected in a patient suffering from a dermoid cyst of the mesentery. Early recognition of the teratoma is important, since only removal of the tumor is consistently curative. Investigations showing immunocompetent cells within the cyst's wall lend further support to the contention that the tumor tissue itself produces, for reasons yet unknown, antitumor autoantibodies that could cross-react with the patient's erythrocytes. The role of computerized tomography (CT) in the diagnosis of abdominal teratoma is emphasized, since CT has permitted visualization of the cystic structure of the tumor before the surgical removal of the mass.

Adolescent↗

Distribution of polyanionic sites in the developing gonads and the dorsal mesentery of the chick embryo.

The distribution of glycoconjugates was investigated in the embryonic trunk mesoderm used as a substrate by migrating primordial germ cells (PGCs) by means of ultrastructural cytochemistry. In both mesentery and developing gonads polyanionic sites were abundant in epithelial and mesenchymal cell coats, basal laminae, and extracellular matrices (ECM). In the latter, polyanions distributed on microfibrils and granules were associated with collagen fibers, forming an entangled network. No preferential association of this fibrillo-granular material with PGCs was observed, suggesting that polyanions present in ECM likely act by promoting inflation of the extracellular spaces rather than by providing mechanical guides for the moving cells.

Animals↗