Post-capillary venules in the human lymph nodes draining malignant tumours.

A total of 275 regional lymph nodes from an equal number of patients with either breast, bronchial, colorectal, gastric or kidney carcinoma were histologically evaluated with special attention focused on the structure of the post-capillary venules (PVC). Three grades of PVC were differentiated on the basis of their endothelial cell morphology and the post-capillary venule score (PCV-S) was calculated for each of the nodes studied. The highest PCV-S was obtained for the control nodes followed in decreasing order by the breast carcinoma series, the renal carcinomas, the gastric carcinomas, the colorectal carcinomas and the bronchial carcinomas. The statistical significances between the PCV-S values obtained were calculated and the possible relationship between these structural changes in PCV endothelium and the T-lymphocyte recirculation was discussed.     

Venous oxygenation in the diabetic neuropathic foot: Evidence of arteriovenous shunting?

Summary Venous PO₂ was measured in the feet and hands of four subject groups: 14 diabetics with neuropathy and foot ulceration; 12 diabetics with neuropathy but no ulceration; 11 diabetics with no evidence of microvascular complications; and 10 nondiabetic controls. Neither patients nor controls had clinical evidence of peripheral vascular disease. The mean venous PO₂ in the feet of subjects with neuropathy and foot ulceration was significantly higher than in controls or the other two diabetic groups. Venous PO₂ in the feet of the subjects with ulcers was also significantly higher than in their hands or in the hands of the other groups. These results provide further evidence of abnormal blood flow in the diabetic neuropathic foot and are compatible with arteriovenous shunting.     

Hemobilia from pancreatic arteriovenous malformation: successful treatment with transportal coil embolization of draining veins

Pancreatic arteriovenous malformations (AVM) are extremely rare diseases frequently complicated by gastrointestinal hemorrhage. While surgical resection of affected lesion is preferred for the treatment of pancreatic AVM, angiographic intervention can be used as an alternative treatment, especially in surgically high-risk patients. We experienced a patient with pancreatic AVM manifested by hemobilia and biliary sepsis. Superior mesenteric and common hepatic arteriography showed pancreaticoduodenal AVM composed of nidus supplied by numerous fine feeding arteries and of draining veins encircling the common bile duct (CBD). Hemobilia was controlled by transportal coil embolization of draining veins of AVM around the CBD. Herein, we report this case with the review of literatures.     

Contrast transesophageal echocardiographic detection of a pulmonary arteriovenous malformation draining into left lower pulmonary vein

We report the identification of a pulmonary arteriovenous malformation draining into the left lower pulmonary vein by contrast two-dimensional transesophageal echocardiography in an adult with no evidence of hereditary hemorrhagic telangiectasia. To our knowledge, this has not been reported previously. This study also emphasizes the importance of transesophageal echocardiographic examination of the left lower pulmonary vein in the detection of a pulmonary arteriovenous malformation.     

Determinants of endothelial cell phenotype in venules

Inflammatory stimuli cause plasma leakage and leukocyte adhesion in venules but not in capillaries or arterioles. The specific response of venules is governed by phenotypic specialization of the venular endothelial cells. What regulates this specialized phenotype? Several recent developments have shed new light on this question and may challenge our thinking about regulation of the venular endothelial cell phenotype. In this review, we consider some of the molecular markers of venular endothelial cells, the hemodynamic and molecular factors that may regulate the phenotype of venular endothelial cells, and abnormalities in endothelial cell phenotype in disease‐related angiogenesis and microvascular remodeling. The expanding list of molecular markers may help clarify the physiologic and molecular factors that regulate the phenotype of venular endothelial cells in normal development and disease.     

Ultrasonics in the monitoring of portasystemic anastomoses

Mortality due to recurrent variceal esophageal bleeding secondary to portosystemic shunt thrombosis is high. Early diagnosis of shunt thrombosis is therefore necessary. For these reasons, patients who have undergone a portal diversion must be controlled periodically. To this end, frequent controls, using reliable, riskless and inexpensive methods are needed. In this work, 34 patients who underwent different types of portal systemic shunts were studied by ultrasonography. Diagnosis by ultrasonography (confirmed by radiography showing esophageal varices and sometimes by arteriography) was positive with direct vision of the anastomosis in 65 p. 100 of cases and with indirect signs of patency or thrombosis of the anastomosis in 32 p. 100 of cases. This method failed to conclude in 3 p. 100 of our cases.     

Role of the actin cytoskeleton in regulating endothelial permeability in venules

OBJECTIVE: This study was performed to determine the effect of myosin light chain kinase (MLCK) inhibition on histamine- and thrombin-induced venular permeability in the rat mesentery, coincidental with actin cytoskeleton changes. METHODS: The mesenteric microvasculature of rats was perfused with a fluorescent tracer plus thrombin, histamine, or buffered saline, and the preparation was suffused with the MLCK inhibitor ML-7. The microvasculature then was stained for actin. RESULTS: The average (+/- SE) number of leaks per micrometer of venule length of the thrombin plus 5 microM ML-7 treatment (35.3 +/- 5.9 x 10(-4); n = 224) was significantly lower than that for the thrombin-only treatment (61.7 +/- 5.6 x 10(-4); n = 385; p < 0.001). The histamine preparations required higher concentrations of ML-7 to significantly reduce the number of leaks. A concentration of 100 microM reduced the average leak number from 20.8 +/- 3.9 x 10(-4) (n = 140) to 2.5 +/- 0.8 x 10(-4) (n = 383; p < 0.001), but 20 microM ML-7 had no effect. Although leaky areas of both the thrombin- and histamine-treated preparations showed disruptions of the peripheral actin rim coincident with fluorescein isothiocyanate-bovine serum albumin leaks, qualitative and quantitative differences were identified. CONCLUSIONS: The results suggest both similar and dissimilar mechanisms for thrombin and histamine regarding in situ endothelial gap formation.     

Lymph draining from foot joints in rheumatoid arthritis provides insight into local cytokine and chemokine production and transport to lymph nodes

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by inflammatory reactions in joints and adjacent tissues unaccompanied by clinically evident changes in lymphatics and lymph nodes draining the inflamed areas. The explanation for this phenomenon, which contrasts with infectious processes in joints and soft tissues that evoke major changes in the lymphatic system, is unclear. To determine which inflammatory factors produced in the joints of RA patients are transported in lymph to lymph nodes, we measured levels of immunoglobulins, cytokines, and chemokines in prenodal lymph from the foot joints of RA patients and quantified their rate of transport to regional lymph nodes. METHODS: Lymph was collected from the cannulated lymphatics draining the foot joints, tendons, fascia, and skin of 20 RA patients. Lymph flow rate and concentrations of proteins and immunoglobulins were measured. Cytokine and chemokine levels were quantified by enzyme-linked immunosorbent assays. Results were compared with those obtained in 20 control subjects. RESULTS: In the cannulated vessel, the mean +/- SEM lymph flow rate in RA patients was almost 2-fold that in control subjects (22.6 +/- 3.2 ml/24 hours versus 13.2 +/- 1.1 ml/24 hours; P < 0.01). Lymph concentrations of total protein, IgG, and IgM were 1.80 +/- 0.14 gm/dl, 384 +/- 45 mg/dl, and 32.0 +/- 1.5 mg/dl, respectively, in RA patients and 1.66 +/- 0.14 gm/dl, 238 +/- 32 mg/dl, and 15.0 +/- 1.3 mg/dl, respectively, in control subjects. The corresponding lymph:serum (L:S) ratios were 0.21 +/- 0.02, 0.22 +/- 0.02, and 0.15 +/- 0.02, respectively, in RA patients and 0.22 +/- 0.02, 0.19 +/- 0.02, and 0.11 +/- 0.02, respectively, in control subjects. The L:S ratios of <1 and the absence of significant differences between groups suggested a lack of local production of immunoglobulins. In RA patients, lymph concentrations (in pg/ml) were as follows: interleukin-1beta (IL-1beta) 14.8 +/- 3.9, IL-6 511 +/- 143, tumor necrosis factor alpha (TNFalpha) 9.9 +/- 1.1, IL-1 receptor antagonist (IL-1Ra) 4,274 +/- 737, IL-10 13.3 +/- 4.4, IL-8 846 +/- 174, IL-15 6.2 +/- 0.9, granulocyte-macrophage colony-stimulating factor (GM-CSF) 2.30 +/- 0.15, vascular endothelial growth factor (VEGF) 80.4 +/- 8.6, and macrophage inflammatory protein 1alpha (MIP-1alpha) 171 +/- 34. In control subjects, these values were as follows: IL-1beta 1.50 +/- 0.25, IL-6 79.0 +/- 14.6, TNFalpha 4.4 +/- 1.1, IL-1Ra 208 +/- 52, IL-10 0.0, IL-8 216 +/- 83, IL-15 5.00 +/- 0.45, GM-CSF 0.40 +/- 0.05, VEGF 42.0 +/- 2.4, and MIP-1alpha 3.4 +/- 1.7 (P < 0.05 versus RA patients for all except IL-15). The L:S ratio was >1 in all RA patient samples for IL-1beta, IL-6, IL-1Ra, IL-8, GM-CSF, IL-10, IL-15, TNFalpha, and MIP-1alpha, indicating local production of cytokines. Great variability in lymph cytokine concentrations, presumably reflecting differences in the intensity of local inflammation, was not reflected in serum cytokine concentrations. Intravenously infused methylprednisolone decreased lymph cytokine levels to normal within 12 hours. In contrast, their concentrations in serum showed little or no change. CONCLUSION: High lymph concentrations of cyto kines and chemokines, exceeding those in serum, were found in RA patients. The L:S concentration ratios of > 1 indicate the local production of these cytokines and chemokines in the inflamed tissues. High flow rates of lymph containing high cytokine concentrations through the regional lymph nodes are likely to affect node lymphocytes and dendritic cells. Analysis of cytokines in lymph should provide insight into events in inflamed tissues in RA and in regional lymph nodes.     

Healing of colonic ischemic anastomoses in the rat

PURPOSE: The aim of this study was to evaluate the role of superoxide radicals in the healing of ischemic colonic anastomoses in the rat. METHODS: Adult male Wistar rats were used in a factorial design with two factors (normal or ischemic colonic anastomoses) each having two levels (treatment with saline or allopurinol). Colonic anastomoses were performed either in normal or previously devascularized colons (ischemic anastomoses) at identical locations, using the same technique. On the fourth postoperative day, animals were killed, and specimens were taken for determinations. RESULTS: Ischemic anastomoses displayed significant increases in superoxide radical (assayed as superoxide anion), superoxide dismutase, and glutathione peroxidase concentrations. Bursting strength and hydroxyproline levels were also significantly lower in these anastomoses. Allopurinol administration elicited a significant decrease in superoxide anions and raised both bursting strength and hydroxyproline levels only in ischemic anastomoses. CONCLUSIONS: Superoxide radicals are involved in the delay in healing of ischemic anastomoses. Allopurinol lowers superoxide anion production and has beneficial effects on the cicatrization of ischemic anastomoses.     

The distensibility of single capillaries and venules in the cat mesentery

The distensibility of single capillaries and venules of the cat mesentery has been determined using a simple technique in vivo. Selected vessels were occluded under microscopic control and red cell oscillation in the occluded segment was monitored using cinemicrography. The cells were seen to oscillate in synchrony with local vascular pressure which was recorded simultaneously using the servo-null technique. Less than 10% of the oscillation could be accounted for by filtration/reabsorption so the bulk of the movement was thought to be a consequence of distension of the vessel during systole and relaxation during diastole. Changes in radius would be amplified by the factor 2¢l/r (where r is radius and ¢l the length of the occluded vessel) to give the observed movement of red cells. Mean pulse pressure was 3.2 mm Hg in capillaries and 2.3 mm Hg in venules which gave rise to increases in radius of 0.03 and 0.028 μm, respectively. The nature of the structure supporting the vessels was considered and it seemed likely to be the basement membrane which would require a Young's modulus of 1.8 × 10⁶ N m⁻² for the capillary and 5.4 × 10⁶ N m⁻² for the venule although pericytes might contribute to support of the latter. It is considered likely that some of the higher values quoted in the literature are due to measurements being made at different ends of a nonlinear stress-strain curve, the present data being obtained at the low stresses normally found in mammalian microvessels.     

Comparison of functional results of ileorectal and ileo-anal anastomoses in familial adenomatous polyposis. Conversions of ileorectal anastomoses into ileo-anal anastomoses]

The aim of this study was to compare the functional results of ileo-rectal anastomosis and ileal pouch-anal anastomosis in a group of patients with familial adenomatous polyposis who had conversion of a ileorectostomy into a ileal pouch-anal anastomosis. In 2 cases (8.3 percent), the conversion was impossible because of abdominal desmoid tumors. For the remaining 21 patients, with more than 1 year follow-up, the number of bowel movements per 24 hours was 3.8 +/- 0.2 before and 4.6 +/- 0.3 after conversion. Daytime and nighttime continence and sensation of the need to defecate were unchanged. The number of patients having nocturnal bowel movements were higher after the pouch procedure (40 vs 10.5 percent). After ileorectostomy and after conversion, 89.5 and 80 percent of the patients had good functional results respectively. Ninety percent of the patients said that results were unchanged or improved after the conversion. In familial adenomatous polyposis the functional results of ileal pouch-anal anastomosis are similar to those of ileorectostomy but the first procedure eradicates the risk of rectal cancer. A conversion to ileal pouch-anal anastomosis should to be proposed to patients with ileorectostomy and at high risk for rectal cancer.