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The angiographic findings in two patients with carcinoids of the small bowel and lymph node metastases in the mesentery are described. Variations from the typical arteriographic appearances of small bowel carcinoids are discussed.
Diseases of mesentery and greater omentum are commonly the result of lymph node metastases from an abdominal carcinoma, or lymph node involvement as part of a general lymphatic malignancy. Primary tumours are rare. Cysts occur predominantly in children. In addition, one may find mesenchymal benign or malignant tumours, which produce clinical symptoms at a later age. Plain abdominal films, barium meals and angiograms fail to show evidence of a space-occupying lesion, or produce only indirect signs. Only ultrasound or CT can demonstrate these tumours directly.
In the search for metastases computed tomography and ultrasonography of the abdomen were performed in a 47-year-old man with a known malignant melanoma in the left lower leg. Numerous fluid-filled cavities, about 8 cm in diameter, were an incidental finding. He died two years after diagnosis of the melanoma, which had extensively metastasized. At autopsy a large multicystic tumour (21 x 15 x 8 cm) was found in the mesentery of the small intestine. The cysts were filled with chyle. Histologically they proved to be multicystic lymphangiomas. Mesenteric lymphangiomas are very rare, multicystic ones and manifestation in adults even more so.
One of the most important functions of the blood circulation is O2 delivery to the tissue. This process occurs primarily in microvessels that also regulate blood flow and are the site of many metabolic processes that require O2. We measured the intraluminal and perivascular pO2 in rat mesenteric arterioles in vivo by using noninvasive phosphorescence quenching microscopy. From these measurements, we calculated the rate at which O2 diffuses out of microvessels from the blood. The rate of O2 efflux and the O2 gradients found in the immediate vicinity of arterioles indicate the presence of a large O2 sink at the interface between blood and tissue, a region that includes smooth muscle and endothelium. Mass balance analyses show that the loss of O2 from the arterioles in this vascular bed primarily is caused by O2 consumption in the microvascular wall. The high metabolic rate of the vessel wall relative to parenchymal tissue in the rat mesentery suggests that in addition to serving as a conduit for the delivery of O2 the microvasculature has other functions that require a significant amount of O2.
Pacinian corpuscles in the mesentery of adult cats were fixed with either glutaraldehyde, osmium tetroxide or permanganate solutions by close intra-arterial injection through the mesenteric artery, and were processed, after electron staining and Epon embedding, for electron microscopy. Better resolution of the corpuscle's ultrastructure was obtained than available heretofore. The myelinated segment of the corpuscle contains blood vessels separated from the axon by collagen fibers and 3 to 4 layers of lamellae. No blood vessels are found in the central core, though access from the vessels is afforded by diffusion through the "cleft" of the inner core. Two cell types are discernible in the inner core hemilamellae; the "clear cells" in which pinocytotic vesicles and organelles abound and reflect the greater metabolic activity of these cells, in contrast to the "dark cells." The ultraterminal is ellipsoidal in form with projections into the "cleft" which give this portion an irregular appearance in section. The terminal and ultraterminal are packed with mitochondria, and "synaptic" vesicles are seen in the ultraterminal. The innermost laminae of the inner core cells are in close apposition to the terminal and break their regular pattern of hemilamellation to surround the small ultraterminal projections at the apical part of the corpuscle.
We report 38 cases of inflammatory fibrosarcoma occurring in 23 females and 15 males, 2 months to 74 years of age (median, 8.5 years; mean, 15 years) with symptoms of abdominal pain (17 cases), anemia (21 cases), fever (14 cases), mass (16 cases), and gastrointestinal obstruction (7 cases). Primary tumor sites included mesentery and retroperitoneum (31 cases), omentum (two cases), mediastinum (two cases), liver (one case), diaphragm (one case), and abdominal wall (one case). Sizes ranged from 2.4 cm to 20 cm (mean, 9.6 cm). Follow-up data in 27 cases revealed local recurrences in 10 patients, with multiple local recurrences in three and histologically proven distant metastases to lung (two cases) and brain (one case). Five patients died from their disease (median, 20 months). All tumors, including metastases, consisted of fibroblasts, myofibroblasts, and plasma cells, with variable degrees of fibrosis and calcification. Immunostains indicate myofibroblastic differentiation; 18 of 20 (90%) stained for actin, 15 of 18 (83%) for vimentin, and 10 of 13 (77%) for keratin (primarily in a submesothelial location). Ultrastructural studies also disclosed myofibroblastic features. The locally aggressive, recurrent nature of these neoplasms, as well as the occurrence of metastases and tumor deaths, indicate that they are potentially malignant neoplasms that we believe are better classified as inflammatory fibrosarcomas, not as cellular inflammatory pseudotumors.
Although the majority of mesenchymal lesions of the gastrointestinal tract are neoplastic in nature, nonneoplastic reactive processes may involve the gastrointestinal tract and mesentery, causing diagnostic confusion with more aggressive neoplasms, such as fibromatosis or gastrointestinal stromal tumors. In this study, we report a series of fibroinflammatory lesions of the gastrointestinal tract that we think represent a relatively cohesive group of tumors and describe the clinical and pathologic features of this entity, which we have termed "reactive nodular fibrous pseudotumor." The tumors affected five patients (four male and one female patient) who ranged in age from 48 to 71 years (mean 56 years). Two patients presented with acute abdominal pain without a significant past medical history, two had incidental lesions discovered during evaluation for other medical conditions, and one was found to have an abdominal mass. Three patients had a history of abdominal surgery. The tumors were multiple in three patients and solitary in two patients. In four cases, at least one of the tumors involved the small intestine or colon, and the lesion was confined to the peripancreatic soft tissue in one case. The tumors were firm, tan-white, ranged in size from 4.3 to 6.5 cm in greatest dimension, and were grossly well circumscribed. All of the lesions were of low to moderate cellularity and composed of stellate or spindled fibroblasts arranged haphazardly or in intersecting fascicles. Three cases had microscopically infiltrative borders. The stroma was rich in collagen, which was wire-like, keloidal, or hyalinized. Intralesional mononuclear cells were sparse but were more numerous peripherally and frequently arranged in lymphoid aggregates. Immunohistochemical stains demonstrated that all of the tumors stained for vimentin, 80% stained for CD117 or muscle specific actin, 60% stained for smooth muscle actin or desmin, and none of the tumors stained for CD34, S-100 protein, or anaplastic lymphoma kinase-1. Follow-up information was available in all cases: four patients had no residual disease following surgical resection (mean follow-up 16.3 months) and one patient who had an incomplete surgical resection had stable disease at 26 months. In summary, we report a series of distinct intraabdominal fibroinflammatory pseudotumors that we have collectively termed "reactive nodular fibrous pseudotumors." These lesions are uncommon and may infiltrate the bowel wall, thereby mimicking primary bowel neoplasms or intraabdominal fibromatosis. Recognition of these nonneoplastic lesions is important, as they pursue a benign clinical course, but may be confused with other mesenchymal neoplasms that require more aggressive treatment.
The mesentery of anaesthetized rats was perfused in situ at a constant rate, via the cannulated superior mesenteric artery, with blood drawn from a cannulated carotid artery. Increases in perfusion pressure were produced by peri-arterial electrical stimulation of the mesenteric sympathetic nerves at 3, 6 and 10 Hz before and after the intravenous administration of frusemide 5 mg/kg. Loss of solutes and volume as a result of frusemide-induced diuresis was prevented by a urinary bladder-venous shunt. In control animals the vasoconstrictor responses to mesenteric nerve stimulation were significantly reduced after frusemide administration. However, in animals pretreated 4 weeks previously with bromethylamine (BEA) 200 mg/kg i.p., frusemide had no effect on vasoconstrictor responses. Chemical papillectomy with BEA has been shown by others to prevent the antihypertensive effects attributed to the non-prostanoid lipids produced by the interstitial cells of the renal medulla. Our data suggest that the vasoconstrictor-inhibiting effect of frusemide may be mediated by the release of renomedullary lipids.
BACKGROUND: The purpose of this study was to identify factors that would aid in the diagnosis of small-bowel and mesentery injuries (SBMI) in blunt trauma patients. METHODS: Retrospective review of 15,779 blunt trauma patients admitted to a Level I trauma center between January 1991 and December 1996. RESULTS: A total of 5,303 patients sustained abdominal injuries, 70 of whom had more than 111 SBMI. Seventy-nine percent were victims of motor vehicle collisions. Thirty patients had isolated SBMI and 40 had associated intra-abdominal injuries. Twelve patients arrived with systolic blood pressure < 90 mm Hg, eight of whom died. Mean base deficit was -7.3 +/- 6.3 in 52 patients who had arterial blood gases determined. Fifty-three of 60 patients had hematuria. Sixty-seven patients required laparotomy. Delayed exploration occurred in 15 patients who underwent initial computed tomography but had subsequent changes in physical status. Two of 20 patients had negative diagnostic peritoneal lavage on admission and were eventually explored based on abdominal computed tomographic findings and changes in physical examination. There were 15 deaths. Delay in diagnosis (>12 hours after arrival) occurred in nine patients with no deaths or significant morbidities. Mean Injury Severity Score was 29 +/- 16.7: 43 +/- 17 in nonsurvivors and 25 +/- 14.3 in survivors (p < 0.05). CONCLUSION: The diagnosis of SBMI is often made in the presence of associated intra-abdominal injuries. Isolated SBMI are common, however, and special attention to the mechanism of injury, abdominal examination, presence of hematuria, and significant base deficit should raise suspicion to the possibility of SBMI. Findings on abdominal computed tomography that may suggest SBMI and should prompt further evaluation include free fluid, thickened bowel, and extraluminal air. Because delay in diagnosis does not seem to affect morbidity or mortality, dedication to observation and serial physical examinations will aid in the proper identification of elusive SBMI. Mortality, however, does appear to be related to the presence of hypotension on admission and associated injuries.
Angiogenesis may be an important mechanism behind the functional deterioration of the peritoneum leading to ultrafiltration failure in peritoneal dialysis. The present study was designed to compare the angiogenic properties of lactate-, bicarbonate-, and pyruvate-buffered fluids, evaluated separately with and without glucose. Five different fluids (lactate and bicarbonate with and without 2.5% glucose and pyruvate without glucose) were studied for 5 weeks of twice-daily injections in rats. The respective buffers (40 mmol/l) were adjusted to pH 7.2, and sodium, chloride, calcium, and magnesium were present at standard concentrations. The mesenteric window model, based on observation of the translucent peritoneal sections of the small intestine mesentery, was used for immunohistochemical imaging of microvessels (RECA-1 antigen) and macrophages (ED1 and ED2 antigens). All fluids induced angiogenesis as compared with untreated controls. The lactate-buffered fluids induced larger vascularized zones than did their bicarbonate- and pyruvate-buffered counterparts. Angiogenesis was accompanied by a local recruitment of ED1 macrophages from blood. Addition of glucose to the lactate- and bicarbonate-buffered fluids did not seem to alter their pro-angiogenic properties. In conclusion, intraperitoneal exposure to lactate buffer, compared with bicarbonate, stimulates angiogenesis in the presence or absence of glucose.
Rat ascites hepatoma AH66F cells adhered better than AH130 cells to mesentery-derived mesothelial cells (M-cells), though both cells secreted Mr 92,000 matrix metalloproteinase on a gelatin zymogram with similar activity. AH66F cells expressed leukocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1), a ligand of LFA-1, on the cell surface, while AH130 cells had ICAM-1 alone. The adhesion of M-cells of AH66F cells was inhibited to the adhesion level of AH130 cells by anti-rat LFA-1 alpha -and/or beta-chain monoclonal antibody (mAb) and also by anti-rat ICAM-1 mAb. This is the first report to show the LFA-1-dependent adhesion of cells other than leukocytes, because AH66F cells did not express CD45, T cell-alpha beta receptor or Cd11b/c (Mac-1/p150,95). These results indicate that a part of the adhesion of AH66F cells to M-cells is due to LFA-1/ICAM-1 interaction, and we suggest that this characteristic feature of AH66F cells may be related to the malignant properties.
Bringing the ileal conduit through the mesentery is a simple procedure and reduces the incidence of post-operative and late intestinal obstruction.
1. We have investigated the effects of a standardised mixture of hydroxyethylrutosides (HR, Venoruton), a mixture of five of its main components (M) and each of the five components separately (7-mono-HR, 7,4'-di-HR, 7,3',4'-tri-HR, 5,7,3',4'-tetra-HR and 7,3'4'-tri HQ) upon the permeability of single perfused capillaries and venules in the mesenteries of pithed frogs. 2. In each experiment, the hydraulic permeability (Lp) of a single perfused microvessel and the effective osmotic pressure (sigma delta pi) exerted by macromolecules across its walls were estimated by a microcclusion technique, first during control perfusion and then in the presence of a known concentration of test substance. 3. HR, M and 7,4'-di-HR reduced Lp in a similar concentration-dependent manner over the range of 1 microgram ml-1 to 1 mg ml-1 (maximum reduction was to 40% of control Lp at 1 mg ml-1). At perfusate concentrations greater than 1 mg ml-1, these substances reduced Lp to a lesser extent. While the four other test substances reduced Lp significantly when their perfusate concentrations equalled or exceeded 100 micrograms ml-1, they were all less potent than 7,4'-di-HR. 4. The reduction in Lp induced by the mixture of flavonoids was only slightly reversed by subsequent perfusion with flavonoid-free solutions. 5. When permeability was increased by perfusing with protein-free solutions, both HR and 7,4'-di-HR reduced and then reversed the increase in Lp in a concentration-dependent manner over the range of 1 microgram ml-1 to 100 micrograms ml-1. None of the other component flavonoids was effective in restoring Lp under these conditions.
We report the case of a 57-yr-old woman presenting with moderate weight loss, abdominal distension, and lymphedema of the legs and vulva. Computed tomography of the abdomen revealed massive thickening of the rectal wall, mesentery, and retroperitoneum. Primary amyloidosis was diagnosed by immunohistochemistry from the rectum and duodenum. To our knowledge, lymphedema due to primary amyloidosis has not yet been reported. The diagnosis should be presumed in the case of retroperitoneal thickening and lymphedema and can be established by immunohistochemistry.
A case of neuron-specific enolase (NSE)-producing leiomyosarcoma arising in the mesentery of a 62-year-old female is presented. Preoperatively, serum level of NSE was markedly elevated. A well-defined but unencapsulated tumor measuring 14 x 12 x 9 cm was histologically characterized by a fascicular or herring-bone arrangement of atypical spindle or oval tumor cells with vesicular cigar-shaped nuclei, inconspicuous nucleoli and abundant clear to brightly eosinophilic cytoplasm. Immunohistochemically, the tumor was positive for vimentin, alpha-smooth muscle actin, muscle actin, desmin, and gamma-NSE. Postoperatively, serum level of NSE decreased to within normal range. The NSE levels were, however, elevated again as metastatic lesions in the liver had enlarged. The patient died of the liver metastases 10 months after surgery. Serum NSE level can be a useful index of tumor extent and for monitoring treatment of some patients with leiomyosarcoma.
In increase in the concentration of dopamine-beta-hydroxylase (DBH) in the blood perfusates of the heart, spleen and mesentery of pithed rats was detected following selective sympathetic nerve stimulation. Furthermore, the concentration of enzyme released by each organ correlated with the stimulation frequency. The results provide further corroborative evidence that the concentration of DBH in the plasma is related to the degree of sympathetic tone. If the sampling methods described were applied to non-spinalized animals, the concentrations of DBH in organ perfusates could be used as an index of sympathetic nervous tone and thus provide a useful preparation for the study of drugs on the sympathetic nervous system.
When single capillaries in the exposed transilluminated frog mesentery were perfused with solutions containing patent blue V (molecular radius 0-7 nm), unbound T1824 (molecular radius 1-3 nm) and T1824-albumin (molecular radius 3-6 nm), the coloured molecules initially appeared to enter the extracapillary tissues more easily at some places than at others along the length of the vessels. Three patterns of extravascular distribution were observed: (1) High frequency unevenness: patent blue V and unbound T1824 first appeared outside the capillary as spots, bars or bands set at intervals 30-80 mum apart along the length of the vessel. (2) Low frequency unevenness: at later times, the extravascular dye was seen to be unevenly distributed on a much larger scale, with lengths of vessel of up to 400 mum surrounded by little extravascular dye separating similar lengths around which much dye had accummulated. This pattern of distribution was seen for all three solutes. (3) Arteriovenous gradient: perfusions with all three solutes resulted in more extracapillary colouration accumulating around the venous ends of the capillaries. Reasons are given for believing that the distribution of extracapillary solute reflected the distribution of permeability along the length of the capillary. The variations in permeability were attributed to an uneven distribution of small pores along the capillary rather than to presences of large pores.
A preparation of rat mesentery was vascularly isolated from the intestine and perfused with a physiological salt solution containing either Ficoll 70 or bovine serum albumin, to act as colloidal agents. The capillary filtration coefficient (Kf; units, ml. min-1 100 g-1 mmHg-1) was measured by following the weight change after graded increases in venous pressure. At pH values greater than 7.05, Kf, during perfusion with 3 and 4% bovine serum albumin solutions, was 0.219 +/- 0.023 (mean +/- S.E. of mean), ninety-eight observations in thirteen experiments, which was significantly less than the value of 0.507 +/- 0.038 which was obtained during perfusion with albumin solutions at pH less than 7.05, seventy-six observations in eleven experiments, (P less than 0.05). The value of Kf obtained during perfusion with 4% Ficoll solutions was 0.267 +/- 0.018, 119 observations in sixteen experiments, and remained uninfluenced by pH over the same range that had been used with the albumin solutions; however, perfusion of the tissues with Ficoll solutions at pH greater than 7.05, after perfusion with albumin solution pH less than 7.05, did cause the Ficoll-derived value of Kf to rise to 0.502 +/- 0.055, seventy-two observations in eleven experiments. It was concluded that the changes in Kf were not due to pH alone, but were mediated by albumin at acidic pH.