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21.
Attenuation of no-reflow phenomenon, neutrophil activation, and reperfusion injury in intestinal microcirculation by topical adenosine 总被引:4,自引:0,他引:4
Small mesenteric arteries supplying partially isolated jejunal segments were totally occluded for 5 minutes and then released. With video microscopy, blood flow was calculated from measurements of submucosal arteriolar diameter and red blood cell velocity. For the first 30 minutes of reperfusion, the serosa was superfused with a Ringer's vehicle containing either adenosine (ADO; 10(-4) M), acetylcholine (ACh; 10(-5) M), or prostacyclin (PGI2; 3 x 10(-7) M). Thereafter, the substances were removed from the suffusate, and superfusion continued with vehicle alone for an additional 10-30 minutes. These concentrations were equieffective for causing vasodilation. During the first minute of reperfusion, blood flow increased more than 300% of baseline in all groups. Within the subsequent 30 minutes, blood flow fell to 45 +/- 3% of baseline with vehicle alone, which demonstrates the no-reflow phenomenon. While either ADO, ACh, or PGI2 was in the suffusate, vasodilation was persistent. After washout of these substances, the postocclusion blood flows were significantly higher with each treatment than with vehicle alone, which shows that each substance had a positive action. However, with ADO, blood flow was 121 +/- 7% of baseline after washout, whereas with ACh or PGI2, it was 64 +/- 10% or 69 +/- 5% of baseline after washout. This property of ADO was observed if the mucosa was superfused with a Ringer's solution or with a bile salt solution, which suggests that ADO might have similar properties in situ. After 60 minutes of reperfusion, the intestinal villi were short, thick, and edematous with epithelial necrosis and crypt degeneration. ADO attenuated most of these histological changes to a greater extent than either PGI2 or ACh. Furthermore, ADO reduced a biochemical index of neutrophil infiltration; tissue myeloperoxidase concentration was increased to 169 +/- 14% of baseline with vehicle but was increased to 120 +/- 8% with ADO. Overall, these observations suggest that ADO protects the intestine from ischemia-reperfusion injury by causing vasodilation and by inhibiting neutrophil function. The vasodilatory effect probably is a minor component because other vasodilators (ACh and PGI2) had minimal protective effects in these conditions. 相似文献
22.
Introduction : Hypertrophic scar is a devastating sequel to burns and other tangential skin injuries. It follows deep dermal injuries and does not occur after superficial injuries. Nitric oxide (NO) plays many important roles in wound healing from inflammation to scar remodeling. Studies have shown that expression of nitric oxide synthase and nitric oxide production are decreased in human hypertrophic scar. However little is known about NO involvement in the early stages of hypertrophic scarring, because of the lack of an animal model. It was recently reported that the female red Duroc pig (FRDP) makes thick scar, which is similar to human hypertrophic scar. We hypothesized that NO production in wounds on the female, red Duroc pig is similar to that of human hypertrophic scar and that NO involvement in deep wounds is different from that in superficial wounds. Methods : Superficial (0.015” to 0.030”) and deep (0.045” to 0.060”) wounds were created on the backs of four FRDPs. Biopsies were collected at weeks 1.5, 4, 8 and 21 post wounding including samples of uninjured skin. Nitric oxide levels were measured with the Griess reaction assay and normalized with tissue protein level. Results : Superficial wounds healed with an invisible scar whereas the deep wounds healed with scar resembling mild hypertrophic scar. The thickness of the scars from the deep wounds was significantly greater than uninjured skin and healed superficial wounds (p < 0.01). NO levels were increased at 1.5 weeks in deep wounds compared to superficial wounds and uninjured skin (p < 0.05). At 8 weeks, NO levels in deep wounds had returned to the level of uninjured tissue and superficial wounds. By 21 weeks, NO levels had decreased significantly when compared to superficial wounds (p < 0.01). There were no differences in NO levels between uninjured skin and superficial wounds at any time point (p > 0.05). Conclusions : NO production is similar in late, deep wounds on the female, red Duroc pig to that reported in the literature for human hypertrophic scar further validating this animal model. NO production is quite different after deep wounds as compared to superficial wounds in the FRDP. Early elevation in nitric oxide production might account for excessive inflammation in deep wounds that become thick scars in the FRDP. Nitric oxide regulators and effects at early stages of scar formation should be elucidated further and the FRDP appears to be a useful model. 相似文献
23.
24.
Summary— Experiments were designed to determine whether or not indapamide, an antihypertensive agent with vasodilator properties, inhibits endothelium-dependent contractions. Rings of aortae with and without endothelium from spontaneously hypertensive rats (SHR) were suspended in conventional organ chambers for the measurement of isometric force. Acetylcholine and adenosine diphosphate-β-S in the presence of a nitric oxide synthase inhibitor, caused endothelium-dependent contractions, which were inhibited by indapamide. The compound (10−4 M) also slightly reduced the contractions of rings without endothelium evoked by U-46,619, which activates thromboxane-endoperoxide receptors. These results demonstrate that indapamide inhibits endothelium-dependent contractions in the SHR aorta, and suggest that the inhibition is due, at least in part, to the action of the drug on the hypertensive vascular smooth muscle. 相似文献
25.
A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium. 相似文献
26.
Peritoneal fluid concentrations of interleukin-8 in women with endometriosis: relationship to stage of disease 总被引:7,自引:10,他引:7
Gazvani MR; Christmas S; Quenby S; Kirwan J; Johnson PM; Kingsland CR 《Human reproduction (Oxford, England)》1998,13(7):1957-1961
There is increasing evidence that immunological mechanisms play a role in
the pathogenesis and pathophysiology of endometriosis. It was therefore of
interest to study interleukin-8 (IL-8), a chemokine, in the peritoneal
fluid and peripheral blood of women undergoing laparoscopic procedures. The
presence and concentrations of IL-8 in relation to endometriosis,
infertility and abdominal pain were evaluated. Samples of peritoneal fluid
(n = 49) and peripheral blood (n = 50) were obtained from 50 consecutive
patients undergoing laparoscopic surgery for various gynaecological
indications (abdominal pain, infertility, sterilization). IL-8 was present
in the peritoneal fluid of most women (87%). The concentration of IL-8 in
the peritoneal fluid was higher in women with endometriosis compared to
women without (P = 0.02). This difference was more pronounced in early
(stage 1) endometriosis (P = 0.001). IL-8 concentrations in the peritoneal
fluid were also higher in women with early endometriosis compared to women
with later stages of the disease (P = 0.003). Peripheral blood
concentrations did not correlate with peritoneal fluid concentrations of
IL-8 and/or the presence of endometriosis. We conclude that IL-8 is an
important factor that may contribute to the pathogenesis of endometriosis
possibly by promoting neovascularization. This information can be a guide
in the development of new therapeutic approaches for the treatment of
endometriosis.
相似文献
27.
Cord formation in BACTEC 7H12 medium for rapid, presumptive identification of Mycobacterium tuberculosis complex.
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P V Yagupsky D A Kaminski K M Palmer F S Nolte 《Journal of clinical microbiology》1990,28(6):1451-1453
We evaluated cord formation in BACTEC 7H12 medium as a criterion for rapid identification of Mycobacterium tuberculosis complex. Kinyoun-stained smears, prepared from 270 radiometrically positive BACTEC 7H12 bottles, were examined independently by three observers. Smears from 93.2, 88.6, and 83.0% of the M. tuberculosis complex cultures were read as cord positive, and smears from 97.3, 97.8, and 99.5% of the mycobacteria other than M. tuberculosis cultures were read as cord negative by the three observers, respectively. There was 93.3% agreement between the observers. The presence of cords in BACTEC 7H12 medium can be a reliable criterion for rapid, presumptive identification of M. tuberculosis complex. 相似文献
28.
Chimaeric monoclonal antibodies encoded by the human VH26 gene from naïve transgenic mice display a wide range of antigen-binding specificities.
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I J Harmer R A Mageed A Kaminski P Charles M Brüggemann C G Mackworth-Young 《Immunology》1996,88(2):174-182
To elucidate the molecular basis for the ability of antibodies encoded by the human VH26 heavy-chain variable region gene to react with diverse antigens, we have generated 34 hybridomas secreting chimaeric monoclonal antibodies (human mu heavy chain/mouse light chains) from transgenic mice. The transgenic mice carry an immunoglobulin minilocus containing the human VH26 gene, human DH and JH gene segments, and genes encoding the human C mu region. The minilocus in these animals undergoes functional rearrangement resulting in the production of chimaeric antibodies in which human mu heavy chains utilizing the VH26 gene are paired with mouse kappa or lambda light chains. The hybridomas described in this study were generated from naïve animals and were selected solely on the basis of human mu-chain expression. The antibodies described have covalently attached mouse light chains and are multimeric in structure. The binding properties of the antibodies were examined using a panel of both self- and foreign antigens using enzyme-linked immunosorbent assays, agglutination or radio-immunoprecipitation assays and immunofluorescence. Chimaeric immunoglobulins from 21 of the 34 hybridoma clones (61.7%) reacted with one or more antigens, of which 13 (38.2%) reacted with more than two antigens. These studies demonstrate that the VH26 gene, in combination with human DH and JH gene segments, and mouse light-chain genes, is able to encode antibodies with a wide range of ligand-binding specificities. These findings have important implications in the context of the possible origins of autoantibodies encoded by VH26 which may play a role in the pathogenesis of a number of autoimmune conditions. 相似文献
29.
Up-regulation of endothelial nitric oxide synthase inhibits pulmonary leukocyte migration following lung ischemia-reperfusion in mice 总被引:7,自引:0,他引:7
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Kaminski A Pohl CB Sponholz C Ma N Stamm C Vollmar B Steinhoff G 《The American journal of pathology》2004,164(6):2241-2249
Endogenous nitric oxide (NO) is known to modulate post-ischemic inflammatory response in various organs. However, the role of nitric oxide synthase isoforms (NOS) in mediating pulmonary post-ischemic inflammatory response is poorly understood. We therefore studied post-ischemic endothelial adhesion molecule expression and leukocyte migration in endothelial NOS knockout (eNOS-KO) mice subjected to pulmonary ischemia and reperfusion in vivo. Under anesthesia and mechanical ventilation, the left pulmonary hilum in wild-type (WT) and eNOS-KO mice was clamped for 1 hour, followed by reperfusion for up to 24 hours. In WT mice, we observed a selective up-regulation of both eNOS mRNA and protein in lung tissue, while inducible NOS (iNOS) and neuronal NOS (nNOS) remained unchanged. Survival in eNOS-KO mice was reduced due to severe pulmonary edema, underlining an increased susceptibility to ischemia-reperfusion (I/R) injury. Interstitial tissue infiltration by CD18- and CD11a-positive white blood cells as well as lung tissue water content peaked at 5 hours of reperfusion and were found significantly higher than in WT mice. Enhanced leukocyte-endothelial interaction was associated with pronounced up-regulation of vascular cell adhesion molecule (VCAM) in eNOS-KO mice during post-ischemic reperfusion. We conclude that eNOS attenuates post-ischemic inflammatory injury to the lung most probably via inhibition of endothelial adhesion molecule expression. 相似文献
30.