Journals at the University of Arizona
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ELECTRICAL ACTIVITY AND ULTRASTRUCTURE OF BOVINE MESENTERIC LYMPHATICS
No full textMembrane action potentials of bovine mesentericlymphatics were recorded simultaneously with isometriccontractions by use of the sucrose gapmethod. The action potentials always had one-to-onecorrespondence to the con traction waves.From the effects of tetrodotoxin, manganese, cal-calcium-free enviroment, and barium chloride onthe spontaneous contractions, it was suggestedthat calcium current may probably play a majorrole in producing spike discharge in the smoothmuscles. Blood capillaries were found within thesmooth muscle layers as well as in the adventitia
THE MIGRATION OF LYMPHOCYTES ACROSS THE VASCULAR ENDOTHELIUM IN LYMPH NODES: A SCANNING ELECTRON MICROSCOPIC STUDY
No full textEndothelial cells of Postcapillary Venules (PCV)and the passage of lymphocytes through the wallof PCV were investigated with Scanning ElectronMicroscope (SEM) in mesenteric lymph nodes ofrats. Individual endothelial cells of PCV in thelymph node did not have flat surface or were nottypically cubic, but swelled at the central partassuming a foot ball-like shape. Circulating lymphocytesare considered to migrate into lymphatictissues through the wall of PCV from the bloodstream. Two hypotheses, inter-endothelial cellpassage and intra-end othelial cell passage, havebeen proposed. The three-dimensional studies onlymphocytes passing the wall with SEM confirmedthat migrating lymphocytes pushes their way throughthe intercellular space with pressing the adjoining endothelialcells from beginning to end, supporting theformer hypothesis. Invasion of lymphocytes in toendothelial cells were not observed
LYMPHOGRAPHY OF THE EDEMATOUS EXTREMITIES
No full textThe mechanism of secondary lymphedema of the extremities is not always simple to understand.The unsolved mechanism of lymphedema should be further studied from exploring relationship between lymphatic and venous systems each of which has superficial and deep systems respectively
THE SURGICAL TREATMENT OF CHRONIC LYMPHEDEMA OF THE EXTREMITY
No full textTwenty-five patients with lymphedema of theextremity have been evaluated. Thirteen weretrea ted surgically and 12 conservatively. TheThompson buried dermis flap operation is the mosteffective procedure and may be combined withomentaplasty
PULMONARY TRANSVASCULAR FLUID DYNAMICS IN SHEEP DURING HEMORRHAGE
No full textThe effects of hemorrhage on pulmonary hemodynamicsand lung transvascular fluid dynamics werestudied in sheep. We found that 2 hr of hemorrhagecaused a fall in lung lymph flow (p 0.05 ) and nosigificant change in lymph protein concentration.The fall in lymph flow was not due to decreasedvascular surface area since the regional distributionof pulmonary perfusion was not altered during hemorrhage;however the decrease in lymph flow wasassociated with decrease (p 0.05 ) in the calculatedpulmonary microvascular pressure. The extravascularlung water lung content per g blood less dry lungwas increased (p 0.05 ) in the hemorrhaged sheepfrom the control values. Pulmonary edema was notdue to increased lung vascular endothelial permeabiltlysince the net tran vascular protein flux was notincreased. The finding that pulmonary edema occurreddespite the consistent decreases in lymph flowsuggests that edema may be due to hemorrhage-inducedlymphatic "failure" or that edema fluid issequestered in spaces (e.g., endothelial cells) whereit cannot be drained by the lymphatics
MORPHOLOGICAL AND PHYSIOLOGICAL STUDY OF THE EFFECT OF HISTAMINE ON THE ISOLATED PERFUSED RABBIT LUNG
No full textHistamine causes interstitial pulmonary edema, butwhether this is the re ult of an increased permea·bility of the pulmonary circulation or only of thebronchial circulation remains to be determined. Inorder to selectively study the effect of histamine onthe pulmonary ciculation we used an isolatedperfused rabbit lung preparation because in thisspecies, the bronchial circulation is poorly developed.Edema formation was assessed by continuouslymonitoring the weight of the lung perfused at con-stant pressure . These studies were supplemented byelectrn microscopic observations using hemoglobinultrastructural tracer for microvascular permeability.We found that histamine (8.0 ~ µg / 100 mlperfusate) did not cause lung weight to increase.Ultrastructural studies showed that histamtine, atthis dosage, did not cause a greater leakage of hemo-globin than occurred in the control lungs. Thus, wehave concluded that histamine does not increase thepermeability of the pulmonary microcirculation inthe isolated perfused rabbit lung
ON THE EXISTENCE OF STRETCHABLE PORES IN THE EXCHANGE VESSELS OF THE ISOLATED RABBIT LUNG PREPARATION
No full textIn the present work our aim has been to seek evidencefor or againat the existence of stretchableporea in the exchange vessel of the lungs. In isolatedrabbit lungs ventilated by positive pressure and perfusedwith homologous blood we performed repeatedtests with fluid filtration from the exchangevessels. In these tests the outflow pressure was elevatedto specific values for periods of 6 min. Therate of weight gain of the preparation during thelast 2 min of each test period was taken as the rateor fluid filtration from the exchange vessels. Wefound a linear relationship between rate of filtrationand outflow pressure in the range from 5 to 20mm Hg. Thi indicates that the hydraulic conductilftyof the exchange vessels did not change withoutflow pressure and thus that no pore stretchingoccurred within this pressure range. An abrupt increasein filtration rate took place when the outflowpressure was set at 25 or 30 mm Hg. Thehydraulic conductivity of the exchange vessels wastherefore probably increased at these high pressures.Since in 3 lungs this increase in filtration rate wasfully reversible we suggest that a stretching of poresin the exchange vessels of the lungs contributed tothe increase in hydraulic conductivity. This stretchingof pores occurred only when vascular pressureswere at or above the upper level of the physiologicalpressure range for the lungs
THE ERYTHROPOIESIS IN ACUTE LYMPHOBLASTIC LEUKAEMIA A MORPHOLOGIC STUDY
No full textThe erythropoietic part of the bone marrow has been morphologically analyzed in 18 patients with acute lymphoblastic leukaemia, 44 patients with acute myeloblastic leukaemia and in 20 controls. There were significant differences between the find ings in the lymphoid and the myeloid leukaemias and it seems possible that the erythropoietic cells are not involved in the leukaemic process in the lymphoblastic leukaemias in contradiction to the myeloid ones
MICROVASCULAR ALTERATIONS IN THE LYMPH NODE DURING THE BCG-INDUCED IMMUNE RESPONSE
No full textPrevious studies have shown significant microvascular changes during the evolution of the immuneresponse. In order to assess the BCG-induced micro vascular alterations in the lymph node, we injected the left foot pad of 23 rabbit s with 1.6 x 10 6 live BCG/kg weight; the right side served as control.Following a period of 1 to 50 days, microangio graphy and histology of the popliteal lymph nodes were carried out. On the side where BCG was injected, the lymph nodes initially showed a moderately increased cortical, and later, a markedly increased meduliary hypervascularity. Histologically, there was mixed mononuclear cellular infiltration followed by granuloma formation. This latter was temporally related to the florid medullary hypervascularity. No significant changes were present on the control side. The hypervascularity induced by BCG was more intense and longer lasting than that seen with other antigens such as Typhoid O or bovine serum albumin.The results indicate a prominent vascular component in the BCG-induced primary immune response within the regional lymph node
LYMPHOCYTOSIS IN RATS TREATED WITH POLYACIDS
No full textInoculation of rats i.v. with dextran sulfate or polymethacrylic acid causes lymphocytosis. Electron microscopy of sections of cervical lymph nodes incontrol rats showed active passage of small lymphocytes through the high endo-thelial cells (HEC) of the post-capillary venules. In treated rats there was no indication of such passage: the HEC were free of small lymphocytes; and in about 25% of the venules apparently stationary lymphocytes, lacking microvilli, were found appressed to the luminal walls of the HEC