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PubMed1979

Increased circulating bradykinin during hypothermia and cardiopulmonary bypass in children.

To determine whether cold could activate the kallikrein-kinin system in vivo as it does in vitro, the circulating systemic concentrations of bradykinin were serially measured in 10 cyildren with congenital diseases of the heart undergoing corrective cardiac surgery. Bradykinin was measured by radioimmunoassay in blood samples obtained before, during and after profound hypothermia (to 18 degrees C) and cardiopulmonary bypass. The circulating concentrations of bradykinin increased significantly as body temperature decreased during surface cooling. The increase in circulating bradykinin was associated with a decrease in the circulating level of bradykininogen, the precursor of bradykinin. With the onset of cardiopulmonary bypass and hence, removal of the lung and pulmonary converting enzyme from the circulation, there was a further rise in the already elevated concentrations of bradykinin. This is the first in vivo demonstration that hypothermia leads to an increase in the circulating concentrations of bradykinin.

Blood Pressure↗

PubMed1987

Neurotensin levels in the hepatic-portal circulation are inversely related to the circadian feeding cycle in rats.

To investigate whether the circulating level of neurotensin (NT) in the rat is related to either the 24-h pattern in food consumption or environmental lighting conditions, the plasma level of NT was determined every 4 h in the hepatic-portal vein and the abdominal aorta over the course of 24 h. At each time interval, pooled plasma samples from groups of 4 rats were extracted, lyophilized, reconstituted, and subjected to HPLC. Column fractions were radioimmunoassayed with both N- and C-terminal directed antisera. Animals housed in a 12-h light, 12-h dark cycle and given food and water ad libitum had a significant (P less than 0.05) 24-h variation in the level of chromatographically and immunochemically identified NT in the portal circulation while the level of NT in the systemic circulation remained unchanged. The level of NT in portal blood ranged from 12-38 fmol/ml and was highest in the afternoon, 12-16 h after peak feeding. The level of NT in aortic blood never exceeded 7 fmol/ml. Similar results were obtained from animals exposed to constant illumination for 13-32 h with free access to food and water. The release of NT during the fasting phase of the feeding cycle was dependent upon the prior intake of food, since the level of NT in the hepatic-portal circulation of rats housed in 12-h light, 12-h dark cycle and fasted for 20-24 h was about 2-fold less than that observed in animals allowed free access to food. In summary, these data show that the release and circulation of NT are tightly linked to the circadian pattern of food intake and that the greatest release of NT into the hepatic-portal circulation occurs 5-10 h after the cessation of eating during the fasting phase of the feeding cycle.

Animals↗

PubMed2003

The effect of clomethiazole on plasma concentrations of interleukin-6, -8, -1beta, tumor necrosis factor-alpha, and neutrophil adhesion molecule expression during experimental extracorporeal circulation.

UNLABELLED: Clomethiazole (CMZ), a neuroprotective drug, has antiinflammatory actions. We investigated the effects of CMZ administration on plasma concentrations of interleukin (IL)-6, IL-8, IL-1beta, tumor necrosis factor-alpha, and neutrophil adhesion molecule expression during experimental extracorporeal circulation. Five healthy volunteers each donated 500 mL of blood, which was subsequently divided into equal portions. Identical extracorporeal circuits were simultaneously primed with donated blood (250 mL) and circulated for 2 h at 37 degrees C. CMZ was added to 1 of the circuits of each pair to achieve a total plasma concentration of 40 micro mol/L. Blood samples were withdrawn at (i) donation, (ii) immediately after addition of CMZ, and at (iii) 30, 60, 90, and 120 min after commencing circulation. Plasma concentrations of IL-6, IL-8, and tumor necrosis factor-alpha were less in the CMZ group compared with control after 60 min of circulation (2.2 [0.3] versus 3.2 [0.4], 14.9 [4.8] versus 21.9 [18.4], 63.3 [43.5] versus 132.2 [118.9] pg/mL, respectively, P < 0.05). After 120 min of circulation, neutrophils from CMZ-treated circuits showed significantly less CD18 expression compared with control (237.5 [97.4] versus 280.5 [111.5], P = 0.03). The addition of CMZ to experimental extracorporeal circuits decreases the inflammatory response. This effect may be of clinical benefit by decreasing inflammatory-mediated neurological injury during cardiopulmonary bypass. IMPLICATIONS: Enhancement of gamma-aminobutyric acid(A)-mediated effects by clomethiazole (CMZ) and associated neuroprotection has been established in animal models of cerebral ischemia. In an ex vivo study, we demonstrated antiinflammatory activity of CMZ in experimental extracorporeal circulation. This represents a potential neuroprotective mechanism of CMZ in patients undergoing coronary artery bypass surgery.

Acid-Base Equilibrium↗

PubMed2003

Quantitative analysis of circulating mitochondrial DNA in plasma.

BACKGROUND: Recent studies have demonstrated the existence of circulating mitochondrial DNA in plasma and serum, but the concentrations and physical characteristics of circulating mitochondrial DNA are unknown. The aim of this study was to develop an assay to quantify mitochondrial DNA in the plasma of healthy individuals. METHODS: We adopted a real-time quantitative PCR approach and evaluated the specificity of the assay for detecting mitochondrial DNA with a cell line (rho(0)) devoid of mitochondria. The concentrations and physical characteristics of circulating mitochondrial DNA were investigated by experiments conducted in three modules. In module 1, we evaluated the concentrations of mitochondrial DNA in plasma aliquots derived from four blood-processing protocols. In module 2, we investigated the existence of both particle-associated and free forms of mitochondrial DNA in plasma by subjecting plasma to filtration and ultracentrifugation. In module 3, we used filters with different pore sizes to investigate the size characteristics of the particle-associated fraction of circulating mitochondrial DNA. RESULTS: The mitochondrial DNA-specific, real-time quantitative PCR had a dynamic range of five orders of magnitude and a sensitivity that enabled detection of one copy of mitochondrial DNA in plasma. In module 1, we found significant differences in the amounts of circulating mitochondrial DNA among plasma aliquots processed by different methods. Data from module 2 revealed that a significant fraction of mitochondrial DNA in plasma was filterable or pelletable by ultracentrifugation. Module 3 demonstrated that filters with different pore sizes removed mitochondrial DNA from plasma to different degrees. CONCLUSIONS: Both particle-associated and free mitochondrial DNA are present in plasma, and their respective concentrations are affected by the process used to harvest plasma from whole blood. These results may have implications in the design of future studies on circulating mitochondrial DNA measured in different disease conditions.

Blood Circulation↗

PubMed2003

Surgical myocardial revascularization without extracorporeal circulation.

OBJECTIVE: To assess the immediate postoperative period of patients undergoing myocardial revascularization without extracorporeal circulation with different types of grafts. METHODS: One hundred and twelve patients, 89 (79.5%) of whom were males, were revascularized without extracorporeal circulation. Their ages ranged from 39 to 85 years. The criteria for indicating myocardial revascularization without extracorporeal circulation were as follows: revascularized coronary artery caliber > 1.5 mm, lack of intramyocardial trajectory on coronary angiography, noncalcified coronary arteries, and tolerance of the heart to the different rotation maneuvers. RESULTS: Myocardial revascularization without extracorporeal circulation was performed in 112 patients. Three were converted to extracorporeal circulation, which required a longer hospital stay but did not impact mortality. During the procedure, the following events were observed: atrial fibrillation in 10 patients, ventricular fibrillation in 4, total transient atrioventricular block in 2, ventricular extrasystoles in 58, use of a device to retrieve red blood cells in 53, blood transfusion in 8, and arterial hypotension in 89 patients. Coronary angiography was performed in 20 patients on the seventh postoperative day when the grafts were patent. CONCLUSION: Myocardial revascularization without extracorporeal circulation is a reproducible technique that is an alternative for treating ischemic heart disease.

Adult↗

PubMed2026

Genetically Predicted Gene Expression and Circulating Metabolites Associated with Cervical High-Grade Squamous Intraepithelial Lesion: A Mendelian Randomization Study.

BACKGROUND: High-grade squamous intraepithelial lesion (HSIL) is a precancerous condition of the cervix. Identifying risk factors associated with HSIL and understanding their potential mechanisms may inform prevention strategies. This study aimed to investigate the associations of genetically predicted gene expression and circulating metabolites with HSIL risk using Mendelian randomization (MR). METHODS: We performed two-sample MR analysis to evaluate the associations of genetically predicted gene expression (eQTLGen consortium, N=31,684) and circulating metabolites (genome-wide association study [GWAS], N=8,299) with HSIL risk (FinnGen R12, N=293,218; 8,291 cases). Mediation analysis was conducted to explore whether metabolites might mediate the associations between genes and HSIL. Sensitivity analyses, including Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO), leave-one-out, and colocalization, were performed to assess the robustness of the findings. All GWAS data used in this study were derived from European-ancestry populations. RESULTS: Eleven genes showed significant associations with HSIL after false discovery rate (FDR) correction (q<0.05), including VWA7, PAX8, GUSBP1, IKZF3, PAX8-AS1, NFKBIL1 (interpret with caution due to an influential single nucleotide polymorphism [SNP]), ERBB2, COL11A2, SKIV2L, TCF19, and PGAP3. Eleven circulating metabolites were also significantly associated with HSIL. Mediation analysis suggested that two phospholipid metabolites (GCST90200685 and GCST90200692) might mediate a small proportion of the total protective association of COL11A2 with HSIL (1.46% and 1.45%, respectively), indicating that the protective association of COL11A2 is largely independent of these circulating metabolites. Colocalization analysis showed strong evidence of shared causal variants for eight genes (PP.H4>0.98), while COL11A2 showed weak evidence of colocalization (PP.H4=1.58×10-15). Functional enrichment analysis indicated that COL11A2-related genes were enriched in extracellular matrix (ECM)-receptor interaction and PI3K-Akt signaling pathways. CONCLUSION: This MR study identified 11 genes and 11 circulating metabolites associated with HSIL risk. Among these, COL11A2 showed a protective association that appeared to be largely independent of circulating phospholipid metabolites, suggesting potential local mechanisms. These findings provide genetic and metabolic clues for future studies on HSIL etiology.

COL11A2↗

PubMed2000

Effects of artificial circulation by pulsatile and non-pulsatile flow on brain tissues.

We examined the effects of artificial circulation by pulsatile and non-pulsatile flow on microcirculation in the brain from the viewpoints of circulation and metabolism in the brain. A centrifugal pump was fixed in the bypass in the right heart of 10 pigs. In 5 of the 10 pigs, a pulsatile flow pump was fixed in the bypass in the left heart (P group), and in the remaining 5 pigs, a centrifugal pump was fixed in the bypass in the left heart (NP group). Hemodynamics were periodically monitored for 3 hours while maintaining about 100 mmHg of the mean aortic pressure. Intracranial pressure (ICP), cerebral tissue blood flow and cerebral blood flow (CBF) were measured and compared with the initial values. As the parameters of metabolism in the brain, the cerebral oxygen consumption and lactic acid - pyruvic acid ratio were evaluated. If the cerebral blood flow was reduced by cardiogenetic shock, we suggest that blood circulation and metabolism in the brain were maintained by artificial circulation. It also indicated that there was no significant difference in blood circulation and metabolism in the brain between artificial pulsatile and non-pulsatile flow circulation.

Animals↗

PubMed1999

Total inversion of the left lung circulation: morphologic and functional analyses.

BACKGROUND: An experimental model for total inversion of left lung circulation was developed. With this model, the authors demonstrate that it is possible to reverse the pulmonary circulation and preserve the normal function and morphology of the lung. METHODS: Eight dogs had their left pulmonary circulation reversed. The blood from the pulmonary artery trunk was diverted to the pulmonary veins, and returned from the pulmonary artery into the left atrium. In order to monitor the flow through the reversed system, color Doppler echocardiography was performed on the ninth postoperative day. The dogs were reoperated after 15 days for re-evaluation. Blood gas analyses from the aorta and the pulmonary artery were used to study the functional status of the lung in both operations. The morphology was studied by comparing biopsies of the lung performed before and after reversal of flow. RESULTS: Blood gas analysis showed no significant difference between the samples of from the aorta and pulmonary artery. Color Doppler echocardiography was a reliable method for the study of the inverted circulation. The histological study showed no differences in the morphology of the lung after the reversed circulation. CONCLUSIONS: Left pulmonary circulation was fully reversed. Pulmonary function and morphology remained normal.

Animals↗

PubMedDate not supplied

[Evaluation of blood flow velocity and cerebrovascular reactivity in patient with posterior circulation stroke].

UNLABELLED: The aim of our study was to determine the type of blood flow disturbances and cerebrovascular reactivity of major anterior and posterior circulation cerebral vessels in patients with posterior stroke (POCI). The examined group consisted of 17 patients, mean age 57 +/- 12 yr, with posterior circulation infarct. Neurological examination, brain CT and Doppler examination including evaluation of BFV and CVR of MCA, PCA and VA was performed in each patient. Doppler examination was done using Pioneer TC 2020 and capnograph Tidal Wave sp Novametrix. RESULTS: BFV of ICA's, MCA's, ACA's and PCA's were diminished while BFV of VA's were significantly diminished in the examined patients compared to healthy controls. CVR of MCA in posterior circulation stroke patients was significantly lower compared to controls. CVR of PCA and VA was significantly lower compared to CVR of MCA in patients with posterior circulation stroke. CONCLUSION: Impairment of CVR, especially in posterior circulation, plays an important role in posterior circulation stroke pathogenesis.

Adult↗

PubMed2003

Viable circulating metastatic cells produced in orthotopic but not ectopic prostate cancer models.

Elucidation of the mechanisms of hormone-independent metastatic prostate cancer remains a significant and highly relevant challenge. We report here that hormone-refractory human prostate carcinoma growing orthotopically efficiently deliver viable metastatic cells in the host circulation. This is in contrast to the ectopic tumors of the same lineage, which do not deliver live cells into the circulation. To investigate the malignant potential of viable circulating carcinoma cells, we developed a novel dual-color orthotopic coimplantation model of human prostate cancer metastasis in nude mice. This model is comprised of coinjection of an equivalent mixture of isolated and cultured circulating green fluorescent protein-expressing clones and parental red fluorescent protein-expressing human prostate carcinoma cells. In the dual-color model, the selected green fluorescent protein-labeled viable circulating cells have an increased metastatic propensity relative to the red fluorescent protein-labeled parental cells. The identification and isolation of highly malignant viable circulating human prostate carcinoma cells from orthotopic but not ectopic models will enable important new insights into the metastatic process including the role of the tumor microenvironment.

Animals↗

PubMed2003

[Interstitial microdialysis study of changes in metabolism and blood flow in skeletal muscles during cardiac surgery with normothermic and hypothermic extracorporeal circulation].

AIM: Hypoperfusion of peripheral tissues and splanchnic organs during cardiac surgery in extracorporeal circulation may lead to the origin of serious complications. The aim of the study was to monitor metabolism and blood pressure in interstital peripheral tissue, skeletal muscle, during the operation on the patient with extracorporeal circulation (ECC) in an early post-operation period by means of microdialysis. METHODS: The interstitial microdialysis is a minimally invasive method for the biochemical monitoring of metabolic changes and blood pressure in extracellular space of tissue. The substances in interstitium pass across a semipermeable membrane of the inserted microdialysis probe and may be analyzed. Microdialysis in this study was performed by means of two microdialysis probes CMA (CMA Microdialysis AB, Sweden) inserted into the deltoid muscle of the surgically treated patient. The probes were perfused by the Ringer solution at the rate of 0.3 ml/hour. The dialysates were sampled in the following intervals: beginning of the operation, beginning of ECC, end of ECC, end of the operation, two hours during the post-operation period. Standard biochemical methods were to evaluate, in the dialysates, glucose, urea, glycerol and lactate. The blood flow in the interstitium was monitored by means of dynamic microdialysis of gentamycine as a marker. Microdialysis was performed in 40 patients with ischemic heart disease, operated on in the extracorporeal circulation. In 20 patients the ECC was performed in normothermia (NT), while in the other 20 patients it was made in hypothermia (HT). RESULTS: In both groups, NT versus HT, a similar dynamism of interstitial concentration of the observed substances in relation to the operation phase and in early post-operation period. Low initial concentrations were gradually increasing during the extracorporeal circulation and increased further after the end of extracorporeal circulation and also in the subsequent phase of the operation. The concentration values of the analytes under observation were higher in the groups operated on under normothermia, apparently due to normal cellular activity during normothermia (versus values in hypothermia). Immediately after the operation the observed values decreased in the both groups and subsequently gradually increased in the post-operation period in the both groups. The trend of dynamic changes of the observed analytes, selected as compounds indicating metabolic activity of skeletal muscles during hypothermia documents a lower metabolic activity of the cells during hypothermia and its marked increase (against NT) in the phase of subsequent normalization of the tissue temperature. Analysis of the concentrations of lactate, as a compounds mapping anaerobic metabolism of skeletal muscle, revealed similar dynamic changes in the both groups (NT vs. HT). There were no significant differences, related to the phase of the operation or the phase of immediate post-operation course when the both groups were compared. The analysis of gentamycine concentrations as a flow marker revealed lower gentamycine concentrations in dialysate during the operation, ECC and the early post-operation course in the group operated on in normotheramia (vs. HT), indicating a higher tissue flow in skeletal muscle against the group of patients operated on under hypothermia. CONCLUSION: The results of the microdialysis study demonstrated dynamic changes in interstitial concentrations of the observed compounds (glucose, urea, glycerol and lactate) related to the phase of operation on the heart in extracorporeal circulation and in early post-operation period. A higher perfusion of skeletal muscle was documented in patients operated on under normothermia. It became obvious that the dynamism in the changes of the compounds observed in the interstitium of skeletal muscle was determined by metabolic activity of the tissue as well as by blood flow in the muscle interstitium.

Aged↗

PubMed2004

Atherosclerotic involvement in patients with left or right dominant coronary circulation.

BACKGROUND: There are variations in the anatomy of the coronary arteries in patients with left dominant circulation. The influence of anatomical variations in patients with left dominant circulation on coronary arteriosclerosis is not clear. AIM: We investigated whether atherosclerotic involvement in patients with left dominant circulation differs from that in patients with right dominant circulation. METHODS: We retrospectively compared 38 consecutive angiograms with left coronary dominance with 459 consecutive angiograms with right coronary dominance. By using the 29-segment coding system of the American College of Cardiology/American Heart Association, numerical values were given to each segment, according to the percentage of the decrease in luminary diameter. Using, the sum of numerical values in each coronary artery, LAD score, LCx score, RCA score, and left main coronary artery (LMCA) score were obtained. Using the sum of these 4 vessel scores, the coronary artery disease (CAD) score was calculated. RESULTS: Total LAD score (49+/-48 vs 47+/-57), total LCx score (29+/-45 vs 41+/-58), total RCA score (32+/-68 vs 30+/-51), total LMCA score (1.8+/-11.3 vs 2.9+/-13.6) and total CAD score (108+/-108 vs 108+/-123) were similar in patients with left and right dominant circulation (all differences NS). CONCLUSIONS: The extent of coronary atherosclerosis does not depend on the type of dominant coronary circulation.

Aged↗

PubMed1992

[Regulation of blood circulation in the extremities in intermittent claudication].

UNLABELLED: The study was aimed to investigate the characteristics of the limb circulation in patients suffering from intermittent claudication. The study group consisted of 71 patients with intermittent claudication. As control served the data of 60 patients with intact peripheral circulation and 24 patients suffering from rest pain, too. The limb blood flow was measured by the venous isotope dye-dilution method. RESULTS: 1. The limb blood flow will be diminished in intermittent claudication already in resting state. The decrease of the limb blood flow is more expressed in severe claudication (with short claudication distance). 2. The pathological condition of the limb circulation in intermittent claudication can be characterized by the elevation of the limb vascular resistance. 3. The O2 consumption of the limb tissues will decrease in intermittent claudication. The data of the study are indicating that the regulation of the limb circulation will pathologically be changed in claudication. The reserves of the peripheral circulation are diminished and the insufficiency of the limb circulation will be manifested on walking.

Adult↗

PubMed2004

Detection of circulating breast cancer cells in peripheral blood by a two-marker reverse transcriptase-polymerase chain reaction assay.

The aim of this study was to use a two-marker assay for the detection of breast cancer cells circulating in patients' blood. We have applied a PCR-based methodology to follow up the possibility of the development of metastatic disease in stage I and II patients who had undergone curative surgery. Since the number of circulating cancer cells in peripheral blood is very low, the technique for their detection needs to be not only highly sensitive, but also very specific. The reverse transcriptase-polymerase chain reaction (RT-PCR) technique may improve the sensitivity of breast cancer cell detection up to only a few cells per one million. The principle of the RT-PCR assay is to amplify a messenger RNA characteristic for breast epithelial cells in a blood sample. Since we do not expect such cells to be circulating in peripheral blood of healthy subjects, detection of the characteristic mRNA should indicate the presence of circulating breast cancer cells. We analyzed the usefulness of three mRNA markers: cytokeratin 19 (CK19), mammaglobin (hMAM) and beta subunit of human chorionic gonadotropin (beta-hCG) for this test. Blood samples (112) were obtained from 55 patients, in stages I and II, with or without metastasis to regional lymph nodes (N0 or N1). We found that a two-marker assay increases the sensitivity of detection of breast cancer cells in comparison with a single-marker one. Combination of two tumor-specific mRNA markers, hMAM/CK19 or beta-hCG/CK19, allowed the detection of circulating breast cancer cells in 65% of N1 patients and 38% of N0 patients. By comparison, the combination hMAM/beta-hCG allowed the detection of circulating breast cancer cells in the blood of 68% of N1 patients and 46% of N0 patients. Addition of the third marker did not significantly increase the detection sensitivity.

Base Sequence↗

PubMed2005

Prognosis of non-small cell lung cancer patients by detecting circulating cancer cells in the peripheral blood with multiple marker genes.

PURPOSE: Current lung cancer staging and prognosis methods are based on imaging methods, which may not be sensitive enough for early and accurate detection of metastasis. This study aims to validate the use of a panel of markers for circulating cancer cell detection to improve the accuracy of cancer staging, prognosis, and as a rapid assessment of therapeutic response. EXPERIMENTAL DESIGN: We analyzed the National Cancer Institute-Cancer Genome Anatomy Project database to identify potential marker genes for the detection of circulating cancer cells in peripheral blood. Nested real-time quantitative PCR and a scoring method using cancer cell load Lc were employed to correlate the amount of circulating cancer cells with clinical outcomes in 54 non-small cell lung cancer (NSCLC) patients. The Kaplan-Meier method was employed for analysis of prognostic variables. RESULTS: A panel of four marker genes was identified and experimentally validated. With these marker genes, we achieved an overall positive detection rate of 72% for circulating cancer cells in the peripheral blood of NSCLC patients. Patients who had higher Lc values had worse outcomes and shorter survival times. Patients with poor therapeutic response were revealed by positive detection of circulating cancer cells after therapy. The results correlated well with the patients' survival time. CONCLUSION: Circulating cancer cell detection by a panel of markers and the Lc scoring method can supplement the current tumor, node, metastasis staging method for improved prognosis and for rapid assessment of therapeutic response. Together, they may facilitate the design of better therapeutic strategies for the treatment of NSCLC patients.

Aged↗

PubMed2005

Alternations of static cerebral and systemic circulation in normal humans during 14-day head-down bed rest.

BACKGROUND: There have so far been few reports on the static regulations of cerebral and systemic circulation during prolonged head-down bed rest (HDBR). Our aim was to investigate the time course changes in static cerebral and systemic circulation during 14 days of 6 degrees HDBR. MATERIAL/METHODS: Sixteen subjects participated in the HDBR study. The systolic, mean, and diastolic cerebral blood flow velocities (CBFVs) of the middle cerebral artery were measured using a transcranial Doppler technique. Cerebrovascular bed resistance indices, i.e., resistance index (RI), pulsatility index (PI), and estimated regional cerebrovascular resistance (CVRest) were calculated. The systemic cardiovascular functions, i.e, heart rate (HR), mean arterial pressure (MAP), left ventricular ejection time (LVET), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were measured or calculated. RESULTS: All CBFVs consistently showed significant decreases from the 2nd day to the last day of the HDBR. The RI and PI showed a rising tendency throughout the HDBR. The CVRest showed significantly higher levels in the later half of the HDBR. The HR and MAP did not change during the HDBR. CONCLUSIONS: The adaptive process of cerebral circulation triggered by HDBR begins very early and leads to a new equilibrium within few days after the onset of HDBR. The alteration of static cerebral circulation with prolonged HDBR, i.e., lowered CBFVs and somewhat higher cerebrovascular bed resistance implies a reduction in the cerebral circulation, but it does not necessarily imply the impaired regulation of cerebral circulation.

Adult↗

PubMed2005

[Changes of neutrophil myeloperoxidase in coronary circulation among patients with acute coronary syndrome].

OBJECTIVE: To investigate the changes of neutrophil myeloperoxidase (MPO) blood concentration gradient between the systemic circulation and the coronary circulation among patients with acute coronary syndrome and its clinical value. METHODS: Fifty patients underwent coronary angiography, which including 10 patients in AMI group, 20 patients in UA group, 10 patients in SA group and 10 subjects served as control. The levels of MPO and hs-CRP were measured in the serum of blood collected from femoral vein, aortic artery root and coronary sinus. RESULTS: Compared with the control, concentrations of LDL in the AMI, UA and SA groups were significantly increased, while the latter three groups did not differ from each other. In the UA patients, the in-gate percentage of MPO decreased in the coronary sinus compared with that in the root of aortic artery (P < 0.01); the in-gate percentage of MPO decreased through coronary circulation more than through systemic circulation (P < 0.001); the average fluorescent intensity of MPO and the concentrations of hs-CRP showed no difference between samples from the coronary sinus and that from the root of aortic artery. In the AMI patients, the average fluorescent intensity of MPO in the coronary sinus was weakened compared with that in the root of aortic artery (P < 0.05); it decreased through coronary circulation more than through systemic circulation (P < 0.001); neither the in-gate percentage of MPO nor the concentrations of hs-CRP showed significant difference between samples from the coronary sinus and that from the root of aortic artery. In the control and SA groups, samples from the femoral vein, the root of aortic artery, and the coronary sinus did not show differences at the serum level of MPO and hs-CRP. In the UA group, the in-gate percentage of MPO correlated positively with the concentration of hs-CRP (r = 0.78, P < 0.01), and with the level of LDL as well (r = 0.52, P < 0.05); In the AMI group, the average fluorescent intensity of MPO correlated negatively with the concentration of hs-CRP (r = -0.80, P < 0.01), and showed no correlation with the level of LDL (r = 0.22, P > 0.05). CONCLUSIONS: MPO is a better marker for inflammation of the local plaques. It may be one of the mechanisms that MPO induces the transforming from LDL to ox-LDL in plaques vulnerability.

Acute Coronary Syndrome↗

PubMed1990

Airway heat and water fluxes and the tracheobronchial circulation.

Breathing dry gas at high minute ventilation leads to heat and water losses from the pulmonary airways. Although these thermal exchanges tend to promote airway cooling and drying, net changes in airway wall temperature and hydration reflect the balance of these losses and restoration of heat and water from circulatory replenishing sources. Because its blood flow rate is small, the tracheobronchial circulation replaces little of the heat loss from the bronchi to the atmosphere; instead, the pulmonary arteries represent the major circulatory heat source for intrapulmonary bronchi. Nonetheless, the tracheobronchial circulation probably acts as an important water replenishing source that helps the bronchi, resist drying, though the precise role of the airway circulation in this regard has not yet been established. Conversely, airway heat and water fluxes caused by dry gas breathing affect the tracheobronchial circulation in two ways. They increase airway systemic blood flow rate, and induce bronchovascular hyperpermeability. Each effect appears primarily as a local response to local airway heat/water losses, but the mechanisms leading to these changes remain uncertain. Furthermore, these vascular responses probably enhance the ability of the tracheobronchial circulation to modulate airway cooling or drying. Thus, airway heat and water exchanges share bidirectional interactions with the airway circulation.

Animals↗