Resistance of ascending vasa recta to transport of water

1991 ◽  
Vol 260 (3) ◽  
pp. F303-F310 ◽  
Author(s):  
T. L. Pallone
Keyword(s):  
Hydraulic Conductivity ◽  
Capillary Pressure ◽  
Single Injection ◽  
Fluorescein Isothiocyanate ◽  
Free Flow ◽  
Volume Flux ◽  
Group I ◽  
Vasa Recta ◽  
Group Ii ◽  
High Hydraulic Conductivity

A study was undertaken to determine the effect of increasing capillary pressure on volume flux in ascending vasa recta (AVR). In one experiment (group I), AVR were blocked by a single injection of paraffin wax and subjected to free-flow microperfusion at 10 nl/min. Collected fluid was obtained from the perfused vessels by micropuncture. In a second experiment (group II), AVR segments were isolated between two paraffin blocks and perfused at 10 nl/min. In group II, the collection pipette was pressurized to 0, 10, or 20 mmHg. Transmembrane volume flux was determined by measuring the change in concentration of fluorescein isothiocyanate-labeled dextran (2 x 10(6) mol wt) from perfusate to collected fluid. In group I, measurements revealed a capillary pressure of 10.3 +/- 0.5 (SE) mmHg and volume flux of 4.3 +/- 1.0 nl.mm-1.min-1. In group II, volume flux was 1.8 +/- 1.3, 5.9 +/- 1.0, and 11.2 +/- 1.1 nl.mm-1.min-1 at collection pressures of 0, 10, or 20 mmHg, respectively. Based on these data and an AVR diameter of 20 microns, AVR hydraulic conductivity is between 12.5 x 10(-6) and 18.7 x 10(-6) cm.s-1.mmHg-1. The papillary AVR have a high hydraulic conductivity. This is consistent with their role as the sole conduit for removal of water from the papillary interstitium.

Molecular sieving of small solutes by outer medullary descending vasa recta

1997 ◽  
Vol 272 (5) ◽  
pp. F579-F586 ◽  
Author(s):  
T. L. Pallone ◽  
M. R. Turner
Keyword(s):  
Water Channel ◽  
Fluorescein Isothiocyanate ◽  
Pressure Gradients ◽  
Volume Flux ◽  
Aquaporin 1 ◽  
A Value ◽  
Vasa Recta ◽  
Mathematical Simulations ◽  
Molecular Sieving ◽  
Hydrophilic Solutes

Molecular sieving of small solutes by outer medullary descending vasa recta (OMDVR). Descending vasa recta (DVR) plasma equilibrates with the medullary interstitium by volume efflux (Jv), as well as by influx of solutes. Jv is driven by transmural osmotic pressure gradients due to small hydrophilic solutes (delta pi s), NaCl and urea. DVR endothelium probably contains a "water-only" pathway most likely mediated by the aquaporin-1 (AQP1) water channel. We measured the ability of microperfused OMDVR to concentrate lumenal 22Na and [3H]raffinose when Jv was driven by transmural NaCl gradients. Collectate-to-perfusate ratios of 2 x 10(6) M(r) fluorescein isothiocyanate-labeled dextran volume marker (RDx), 22Na (RNa), and [3H]raffinose (Rraf) were measured in the absence and presence of Jv. During volume efflux (Jv > 0), RDx was 1.37 +/- 0.31. RNa increased from 0.64 +/- 0.03 when Jv = 0 to 0.82 +/- 0.05 when Jv > 0 and Rraf increased from 0.83 +/- 0.03 to 1.13 +/- 0.05: Mathematical simulations predict RNa and Rraf most accurately when the OMDVR reflection coefficient to the tracers is assigned a value near unity. This indicates that the OMDVR wall contains a pathway for osmotic volume flux that excludes small hydrophilic solutes, a behavior consistent with that of aquaporins.

Transport of sodium chloride and water in rat ascending vasa recta

1991 ◽  
Vol 261 (3) ◽  
pp. F519-F525 ◽  
Author(s):  
T. L. Pallone
Keyword(s):  
Sodium Chloride ◽  
Opposite Direction ◽  
Water Movement ◽  
Fluorescein Isothiocyanate ◽  
Volume Flux ◽  
Vasa Recta ◽  
Isotonic Buffer ◽  
Small Solute

Experiments were undertaken to test the hypothesis that transcapillary small solute (NaCl and urea) gradients drive water across ascending vasa recta (AVR). Axial gradients of NaCl and urea were eliminated with furosemide. AVR were perfused with buffer containing fluorescein isothiocyanate-labeled dextran and 22Na. Perfusion of AVR with isotonic buffer at 10 and 20 nl/min yielded collectate-to-perfusate 22Na ratios of 0.17 +/- 0.05 and 0.34 +/- 0.03, respectively, in AVR of 601 +/- 56 and 583 +/- 46 microns mean length, respectively. A 22Na permeability of 113.2 +/- 12.8 x 10(-5) cm/s was determined. AVR were perfused at 20 nl/min with buffer NaCl of 0 (hypotonic to papilla), 161 (isotonic), or 500 mM (hypertonic). Transcapillary volume flux was not significantly different in these groups (3.8 +/- 1.5, 4.6 +/- 1.5, and 2.1 +/- 1.4 nl.min-1.mm-1, respectively). AVR were perfused in the hydropenic kidney at 5 nl/min antegrade from tip to base and retrograde from base to tip, which was a maneuver designed to impose physiological transcapillary NaCl and urea gradients of opposite direction. Volume fluxes were -1.4 +/- 0.05 and -1.3 +/- 0.04 nl.min-1.mm-1 in these groups, respectively. These data demonstrate that the AVR are highly permeable to NaCl and that physiological small solute gradients do not influence water movement across the AVR wall.

scholarly journals A clinical picture and treatment optimization of acute forms of tick-born encephalitis

2008 ◽  
Vol 7 (5-1) ◽  
pp. 263-269
Author(s):  
M. V. Nadezhdina ◽  
M. G. Toporkova ◽  
N. M. Gurary ◽  
N. A. Makhneva
Keyword(s):  
Single Injection ◽  
Symptomatic Therapy ◽  
Disease Development ◽  
Treatment Optimization ◽  
Acute Period ◽  
Group I ◽  
Tick Borne Encephalitis ◽  
Enzyme Method ◽  
Group Ii ◽  
Period Duration

A comparative clinical and serological analysis of two groups compatible by sex, age and clinical forms of acute tick-born encephalitis was conducted among 68 patients with confirmed immune enzyme method. All patients received a single injection of high titrating Russian human tick-borne encephalitis immunoglobulin by the doze varying on the patient’s weight and particular decease. All patients received symptomatic therapy as well. There were 33 patients in the group II who have been taking anaferon during two weeks since the acute period. The patients of the groups I and II didn’t have any robust alteration of the feverish period duration and cerebrospinal fluid sanitation but it was discovered that the patients of the group II with focal form had reveal predominance of IgM titer on the second week of the disease development comparing with the same indicators among the patients of the group I with focal form. The findings show the possibility to recommend anaferon for complex treatment of the patients with tick-born encephalitis in acute period.

Resistance of descending vasa recta to the transport of water

1990 ◽  
Vol 259 (4) ◽  
pp. F688-F697 ◽  
Author(s):  
T. L. Pallone ◽  
J. Work ◽  
R. L. Jamison
Keyword(s):  
Driving Forces ◽  
Water Movement ◽  
Fluorescein Isothiocyanate ◽  
Hydraulic Pressure ◽  
Volume Flux ◽  
Sample Collection ◽  
Buffer Solution ◽  
Plasma Protein Concentration ◽  
Vasa Recta ◽  
Small Solute

The effect of varying intracapillary oncotic pressure on the rate of transcapillary volume flux in microperfused descending vasa recta (DVR) was studied during furosemide diuresis in the Munich-Wistar rat. At the papillary base, plasma protein concentration and hydraulic pressure were 5.7 +/- 0.1 g/dl and 11.7 +/- 0.7 mmHg in nonperfused DVR, respectively, and 5.6 +/- 0.1 g/dl and 9.4 +/- 0.4 mmHg in nonperfused ascending vasa recta (AVR), respectively. These results demonstrate that the papillary microcirculation does not remove water from the interstitium during furosemide diuresis and defines Starling forces in the pericapillary interstitium. Osmolality and urea concentration were 380 +/- 11 mosmol/kgH2O and 56 +/- 5 mM in DVR plasma at the papillary base, respectively, and 386 +/- 10 mosmol/kgH2O and 62 +/- 5 mM in DVR plasma at the tip, respectively. These results demonstrate abolition of corticomedullary small solute gradients. DVR were perfused at a rate of 10 nl/min with a buffer solution containing small-solute concentrations that matched those of plasma in nonperfused DVR. The buffer solution also contained 2 x 10(6) mol wt fluorescein isothiocyanate-labeled dextran (FITC-Dx, 5 mg/ml) and either 0.1 or 5.0 g/dl albumin. Microperfused DVR were punctured a second time downstream of the perfusion site for sample collection or servo-nulling pressure measurement. The rate of transmembrane volume flux, determined from the change in FITC-Dx concentration from perfusate to collectate, was 0.99 +/- 0.29 nl.min-1.mm-1 when perfusate contained 0.1 g/dl albumin and 0.00 +/- 0.23 nl.min-1.mm-1 with 5.0 g/dl albumin (P less than 0.01). Intracapillary hydraulic pressures were 21.7 and 20.4 mmHg during microperfusion of DVR with 0.1 and 5.0 g/dl albumin, respectively. These results demonstrate that transcapillary driving forces of 20 mmHg (5 g/dl albumin) influence transcapillary water movement across the DVR endothelium. For an average capillary diameter of 12.9 microns, DVR hydraulic conductivity is calculated to be greater than 1.4 x 10(-6) cm.s-1.mmHg-1.

Ultrastructural Lesions Produced by Alcohol and Sucrose in the Heart and Liver of C57BL Mice

1970 ◽  
Vol 28 ◽  
pp. 208-209
Author(s):  
K.K. SEKHRI ◽  
C.S. ALEXANDER ◽  
H.T. NAGASAWA
Keyword(s):  
Osmium Tetroxide ◽  
Male Mice ◽  
Alcohol Group ◽  
Group Iii ◽  
Group I ◽  
C57bl Mice ◽  
Group Ii

C57BL male mice (Jackson Lab., Bar Harbor, Maine) weighing about 18 gms were randomly divided into three groups: group I was fed sweetened liquid alcohol diet (modified Schenkl) in which 36% of the calories were derived from alcohol; group II was maintained on a similar diet but alcohol was isocalorically substituted by sucrose; group III was fed regular mouse chow ad lib for five months. Liver and heart tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmium tetroxide and embedded in Epon-araldite.

Heterogeneity and Immunochemical Properties of Anti-β2-glycoprotein I Autoantibodies

1998 ◽  
Vol 80 (09) ◽  
pp. 393-398 ◽  
Author(s):  
V. Regnault ◽  
E. Hachulla ◽  
L. Darnige ◽  
B. Roussel ◽  
J. C. Bensa ◽  
...  
Keyword(s):  
Fluid Phase ◽  
Anticardiolipin Antibodies ◽  
Dual Reactivity ◽  
Group Iii ◽  
Important Group ◽  
Epitope Specificity ◽  
Glycoprotein I ◽  
Group I ◽  
Group Ii ◽  
Sufficient Concentration

SummaryMost anticardiolipin antibodies (ACA) associated with antiphospholipid syndrome (APS) are directed against epitopes expressed on β2-glycoprotein I (β2GPI). Despite a good correlation between standard ACA assays and those using purified human β2GPI as the sole antigen, some sera from APS patients only react in the latter. This is indicative of heterogeneity in anti-β2GPI antibodies. To characterize their reactivity profiles, human and bovine β2GPI were immobilized on γ-irradiated plates (β2GPI-ELISA), plain polystyrene precoated with increasing cardiolipin concentrations (CL/β2GPI-ELISA), and affinity columns. Fluid-phase inhibition experiments were also carried out with both proteins. Of 56 selected sera, restricted recognition of bovine or human β2GPI occurred respectively in 10/29 IgA-positive and 9/22 IgM-positive samples, and most of the latter (8/9) were missed by the standard ACA assay, as expected from a previous study. Based on species specificity and ACA results, IgG-positive samples (53/56) were categorized into three groups: antibodies reactive to bovine β2GPI only (group I) or to bovine and human β2GPI, group II being ACA-negative, and group III being ACA-positive. The most important group, group III (n = 33) was characterized by (i) binding when β2GPI was immobilized on γ-irradiated polystyrene or cardiolipin at sufficient concentration (regardless of β2GPI density, as assessed using 125I-β2GPI); (ii) and low avidity binding to fluid-phase β2GPI (Kd in the range 10–5 M). In contrast, all six group II samples showed (i) ability to bind human and bovine β2GPI immobilized on non-irradiated plates; (ii) concentration-dependent blockade of binding by cardiolipin, suggesting epitope location in the vicinity of the phospholipid binding site on native β2GPI; (iii) and relative avidities approximately 100-fold higher than in group III. Group I patients were heterogeneous with respect to CL/β2GPI-ELISA and ACA results (6/14 scored negative), possibly reflecting antibody differences in terms of avidity and epitope specificity. Affinity fractionation of 23 sera showed the existence, in individual patients, of various combinations of antibody subsets solely reactive to human or bovine β2GPI, together with cross-species reactive subsets present in all samples with dual reactivity namely groups III and II, although the latter antibodies were poorly purified on either column. Therefore, the mode of presentation of β2GPI greatly influences its recognition by anti-β2GPI antibodies with marked inter-individual heterogeneity, in relation to ACA quantitation and, possibly, disease presentation and pathogenesis.

Treatment of venous leg ulcers with sulodexide

Phlebologie ◽  
2003 ◽  
Vol 32 (05) ◽  
pp. 115-120 ◽  
Author(s):  
A. Franek ◽  
H. Koziolek ◽  
M. Kucharzewski
Keyword(s):  
Pharmacological Treatment ◽  
Healing Process ◽  
Leg Ulcers ◽  
Venous Ulceration ◽  
Venous Leg Ulcers ◽  
Group I ◽  
Group Ii

SummaryAim: The study of the influence of sulodexide in the treatment of venous leg ulcers. Patients and method: 44 patients with chronic venous ulceration were randomly divided into two groups. Group I: 21 patients (ulceration area: 12.7-18.9 cm2), Group II: 23 patients (ulceration size: 12.1-20.3 cm2). Both groups were treated by using Unna’s boot. This dressing was changed every seven days until the ulcer had healed. Additionally, the patients in group II received the systemic pharmacological treatment with sulodexide. Results: After 7 weeks of treatment ulcers of seven patients (35%) from group I had healed, and 3 weeks later the ulceration of two more patients had healed completely. After further 7 weeks the ulcers of 12 patients had healed completely. Whereas in group II after 7 weeks of treatment ulceration of 16 (70%, p <0.05) patient had healed completely and after further 3 weeks the ulcers of the remaining 7 patients had healed, too. Conclusion: The use of sulodexide in patients with chronic venous leg ulcers accelerates the healing process.

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović
Keyword(s):  
Radionuclide Ventriculography ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Volume Determination ◽  
Group I ◽  
Lv Volumes ◽  
Group Ii ◽  
Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

A P-Selectin/CD62P Monoclonal Antibody (LYP-20), in Tandem with Flow Cytometry, Detects in vivo Activated Circulating Rat Platelets in Severe Vascular Trauma

1994 ◽  
Vol 72 (05) ◽  
pp. 745-749 ◽  
Author(s):  
Elza Chignier ◽  
Maud Parise ◽  
Lilian McGregor ◽  
Caroline Delabre ◽  
Sylvie Faucompret ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Platelet Activation ◽  
Peripheral Blood ◽  
Vascular Trauma ◽  
Activated Platelets ◽  
Group I ◽  
Group Ii ◽  
Rat Platelets

SummaryP-selectin, also known as CD62P, GMP140 or PADGEM, is present in platelet a-granules and endothelial cell Weibel-Palade bodies and is very rapidly expressed on the surface of these cells on activation. In this study, an anti P-selectin monoclonal antibody (LYP20) was used, in tandem with flow cytometry, to identify activated platelets at the site of induced vascular trauma or in peripheral blood. Moreover, electron microscopy was performed to characterize sites of vascular trauma and quantify the number of adhering platelets. The same induced vascular trauma was observed to result into animals responding in 2 different ways (Group I, Group II) following the degree of platelet activation. Five rats, out of 14 with induced vascular trauma, had more than half of their circulating platelets expressing P-selectin when drawn at the site of the trauma (67.4% ± 3.44) or in peripheral blood (78.5% ± 2.5) (Group I). In the remaining 9 animals a much smaller proportion of circulating platelets expressed P-selectin when assayed from trauma sites (18% ± 3.34) or in peripheral blood (18.0% ± 4.30) (Group II). Enhanced P-selectin expression by circulating platelets in Group I, compared to Group II, appears to be linked to the degree of activated platelets adhering at sites of trauma (171 ± 15 × 103 platelets versus 48 ± 31 × 103 platelets per mm2). In the 5 control animals, that were not operated on, platelets expressing P-selectin when drawn at the site of a mock trauma (7.0% ± 1.84) or in the peripheral blood (11.2% ± 3.30) showed little activation. In addition, no platelet adhesion was seen on the vascular bed of these animals. Results from this study show that analysis of P-selectin (CD62P) expression, in circulating platelets, is a valuable and rapid marker of platelet activation following severe vascular trauma induced in rats. However, activated platelets were not detected to the same extent in the peripheral blood of all animals having undergone vascular trauma. It is conceivable that platelets, depending on the degree of activation, may be actively sequestered in organs and prevented from circulating. Alternatively, P-selectin may be rapidly endocytosed, or not expressed, by activated circulating platelets depending on the type of agonists implicated in vivo activation.

Assessment of Acute Kidney Injury in Patients Undergoing Elective Coronary Angiography and Percutaneous Coronary Intervention

2012 ◽  
Vol 5 (1) ◽  
pp. 37-43
Author(s):  
ABMM Alam ◽  
M Moniruzzaman ◽  
MB Alam ◽  
N Islam ◽  
F Khatoon ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Contrast Media ◽  
Creatinine Level ◽  
Ace Inhibitor ◽  
Kidney Injury ◽  
Coronary Intervention ◽  
Group I ◽  
Percutaneous Coronary ◽  
The Mean ◽  
Group Ii

Background: CIN has gained increased attention in the clinical setting, particularly during cardiac intervention but also in many other radiological procedures in which iodinated contrast media are used. There is at present good clinical evidence from well-controlled randomized studies that CIN is a common cause of acute renal dysfunction.Methodology: This was a prospective study conducted among the patients who underwent coronary angiography and percutaneous coronary intervention in the Department of Cardiology, Dhaka Medical College Hospital during January 2010 to December 2010. A total of 111 patients age range from 25 to 75 years were included in the study. Serum creatinine level at baseline and at the end of 48 hours was done in all these patients. Study population was divided into two groups according to development of acute kidney injury (AKI). Group-I = AKI, Group II = Not developed AKI. Results: AKI developed 11.7% of the study patient. DM and Preexisting renal insufficiency were significantly higher in group I patients. HTN was (61.5% Vs 44.9%) higher in group I but not significantly. History of ACE inhibitor/ARB, NSAID intake and LVEF <40% were significantly higher in group I patients. The mean±SD volume of CM (Contrast Media) were 156.9±44.8 ml and 115.4±30.0 ml in group I and group II respectively, which was significant. The mean±SD of serum creatinine after 48-72 hours of CAG/PCI was 1.4±0.37 mg/dl and 1.1±0.2 mg/dl in group I and group II respectively. The serum creatinine level increased significantly (p<0.05) after 48-72 hours of CAG/PCI in group I. In group II, S. creatinine level increased but not significant (p>0.05). Impaired renal function was found 76.9% and 2.0% in group I and group II respectively. DM, HTN, preexisting renal insufficiency, ACE inhibitor/ARB, NSAIDs, contrast volume (>150 ml), eGFR (<60 ml/min/ 1.73m2) and LVEF (<40%) are significantly (p0.05) associated for CIN development.Conclusion: CIN is an iatrogenic but preventable disorder results from the administration of contract media. Although rare in the general population, CIN occurs frequently in patients with underlying renal dysfunction and diabetes. In patients with pre angiographic normal renal function, the prevalence is low but in pre-existing renal impairment it may pose a serious threat. Thus risk factors are synergistic in their ability to predispose to the development of CIN. A careful risk-benefit analysis must always be performed prior to the administration of contrast media to patients at risk for CIN. DOI: http://dx.doi.org/10.3329/cardio.v5i1.12227 Cardiovasc. j. 2012; 5(1): 37-43

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