Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bovine Leukocyte Adhesion Deficiency (BLAD) is a genetic disease of cattle affecting the hematopoietic system. In the last decade BLAD has become a disease of economic importance in the dairy industry. As such, this overview describes the chronological developments and thinking that led to the elucidation of BLAD as a distinct disease entity from previous models in canine and human populations. All species affected exhibit symptoms of chronic and recurrent infections. Necrotic and/or gangrenous infections of soft tissues are prevalent, as well as secondary infections with bacteria or fungi. Low birthweight and unthriftiness are key symptoms of neonates in all species affected by LAD. Dermatomycoses and impaired pus formation are also common findings. The physiological basis for BLAD is a deficiency in leukocyte (particularly neutrophil) chemotactic and phagocytic properties. The inhibition of diapedesis in the inflammatory response prevents normal immune reactions to invading pathogens. Chronic infections are a consequence of the faulty immune mechanisms. The biochemical etiology of BLAD involves cell surface glycoprotein molecules known as integrins. These are responsible for cell-cell interactions necessary for neutrophils to adhere to vascular endothelium in a normal individual. Experiments using monoclonal antibodies to block LFA-1, Mac-1, and p150,95 (three integrins vital for cell-cell interactions) mimic BLAD symptomatology and have led to the discovery of the reciprocal Intercellular Adhesion Molecule (ICAM). Through pedigree analysis and biochemical detection with restrictive endonucleases BLAD has been isolated genetically to a single gene locus. The economic significance and prophylaxis are briefly discussed. In addition, the beneficial aspects of the study of BLAD are addressed. There are advantages of producing a BLAD-like state in preventing transplant rejection, ischemia-reperfusion injury, and other scenarios arising from the deleterious effects of the inflammatory response.
 ...
PMID:Bovine leukocyte adhesion deficiency: a brief overview of a modern disease and its implications. 882 96

Although rotational ablation has been successful in the treatment of complex coronary lesions, periprocedural complications of microvascular-mediated ischemia (slow flow or no reflow) and coronary vasospasm may occur. In an attempt to reduce such complications, a drug cocktail consisting of a combination of verapamil 10 micrograms/ml, nitroglycerin 4 micrograms/ml, and heparin 20 U/ml was infused in 21 consecutive patients with AHA/ACC Type B2 and C lesion morphology. A total of 27 lesions were treated, with a procedural success rate of 95%. One patient required emergency bypass surgery. Coronary vasospasm occurred in 7% (2/27 lesions). Only one lesion (3.7%) was associated with a transient reduction in TIMI flow that resolved within 5 min, and none had classical no-reflow. No patient developed intraluminal thrombus, and none had hypotension requiring inotropic support. All patients had prophylactic temporary pacemakers inserted. All RCA and circumflex lesions and 50% of LAD stenoses required transient pacing. A "cocktail" infusion of verapamil, nitroglycerin, and heparin mixed in pressurized saline delivered through the 4-French Teflon sheath of the Rotablator system during rotational ablation is associated with high success and low complication rates. Transient AV block is frequent, especially when treating RCA and circumflex arteries; therefore, prophylactic pacing is indicated.
 ...
PMID:Cocktail attenuation of rotational ablation flow effects (CARAFE) study: pilot. 887 32

A 49-year-old male presented with atypical chest pain. Complete cardiac evaluation was normal except for cardiac catheterization, which revealed a myocardial bridge across the LAD (left anterior descending coronary artery) that caused a 50% systolic stenosis. Abdominal ultrasound revealed cholelithiasis. The patient became asymptomatic and was discharged only to return with biliary pancreatitis, which resolved over 2 weeks and laparoscopic cholecystectomy was attempted. Upon establishment of a pneumoperitoneum, he began to suffer cardiac ischemia, which immediately resolved upon desufflation. The procedure was converted to an uneventful open cholecystectomy. He did well without any further problems. This is the first report of myocardial bridging, a well-known cardiac anomaly, possibly preventing safe laparoscopy. This was possibly due to transmitted intraperitoneal pressure effect on the pericardium pushing closed that myocardial bridge.
 ...
PMID:Myocardial bridging prevents safe laparoscopy? A case report. 887 44

The cardioprotective effect of ischemic preconditioning (PC) was investigated in the anesthetized ferret model of myocardial ischemia followed by reperfusion. PC of 2, 5, or 10-min duration, followed by 10-min reflow, was studied in animals subjected to 60-min sustained LAD coronary artery ischemia followed by 5-h reperfusion. Infarct size was determined by tetrazolium staining. Sham PC ferrets had a mean infarct of 72% of risk zone. A 2-min or 5-min cycle of PC significantly reduced tissue damage to 54% (p < 0.05) and 44% (p < 0.01), respectively. Infarct reduction associated with 10-min ischemic PC was not significant (57% of AAR). The cardioprotective effects of 5-min PC were lost when sustained ischemia was prolonged to 75 or 90-min. Myocardial salvage afforded by 5-min PC was also abolished by both a) inhibition of ATP-sensitive potassium channels using either glyburide or 5-HD and b) blockade of adenosine receptors with the A1 selective agent DPCPX. In the absence of PC, activation of ATP-sensitive potassium channels with the cardiac-selective agonist BMS-180448 significantly (p < 0.01) reduced infarct size from 66% to 37% of the risk zone. Cardioprotection, or its loss, was not the result of hemodynamic alterations occurring during PC, drug administration, or the coronary occlusion and reperfusion phases. Based upon its body size and lack of extensive myocardial collateral circulation the ferret offers a usefull alternative small species for study of ischemia and reperfusion salvage. It is concluded in the ferret that: a) the threshold for PC is less than in either the rat, rabbit, or dog; unlike the dog and pig, the beneficial effects of PC are b) reduced when the ischemic PC interval is extended to 10-min or c) lost if sustained coronary occlusion is maintained for a period of 75-min or longer; and last, a role in PC for both d) ATP-sensitive potassium channels and e) adenosine A1 receptors can be demonstrated.
 ...
PMID:Cardioprotection associated with preconditioning in the anesthetized ferret. 899 28

The concept of direct myocardial revascularization, achieving myocardial perfusion through means other than the normal coronary vasculature, has a long history with the most widely investigated technique being the Vineberg procedure; current interest centers around the encouraging preliminary clinical results obtained with transmyocardial laser revascularization. Despite significant previous research, the acute blood flow potential through the direct myocardial route remains unknown. Nontransmural laser channels were made in the distal LAD territory from the epicardial surface of 5 mongrel dogs to which an internal mammary artery was connected. A flow probe was placed on the distal most portion of the artery and an intercostal branch was cannulated for infusion of colored microspheres. Measurements were taken under baseline conditions and following LAD and epicardial collateral ligation. Under all conditions, blood flow pattern was of a to-and-fro nature. At baseline, there was an average 0.60 +/- 0.24 ml/min net flow into the myocardium which was all contained within 0.5 cm of the central channel with a final myocardial perfusion of 0.011 +/- 0.016 ml/min/g. Following induction of ischemia average flow increased to 1.41 +/- 0.51 ml/min which extended as far as 1 cm from the channel with a final myocardial perfusion of 0.22 +/- 0.19 ml/min/g. In conclusion, a limited amount of acute myocardial perfusion can be achieved by the present technique of direct myocardial revascularization and the amount of flow is highly dependent upon the amount of flow through the native circulation.
 ...
PMID:Blood flow capacity via direct acute myocardial revascularization. 906 51

The influence of intracoronary enoximone at a dose of 0.075 mg/ kg/10 min on global and regional wall motion and myocardial perfusion (Group I, n = 10) as well as on diastolic LV function (Group II, n = 8) during pacing-induced ischemia was investigated in 18 patients with significant LAD stenoses. The hemodynamic parameters were determined by left heart catheterization, the systolic and diastolic left ventricular function by echocardiography including Doppler technique, and myocardial perfusion analysis was done after intracoronary application of contrast medium. Enoximone did not change either heart rate (79 +/- 9 vs 80 +/- 9 min-1) or blood pressure (LVSP: 159 +/- 7 vs 162 +/- 5 mm Hg) at rest. In the postpacing ischemic period after enoximone, LVEDP fell from a mean of 28.9 to 18.4 mm Hg (p < 0.001), dp/dtmax increased from 1050 to 1369 mm Hg/s (p < 0.001) and regional EF from 47% to 58% (p < 0.01), while global EF remained unchanged (45% vs 47%). ST-segment depression was reduced significantly from 2.3 to 1.5 mm (p < 0.01). Enoximone induced an increase in myocardial perfusion by 129% (p < 0.001) in the stenosis-dependent myocardial areas with shortening of the wash-out half-life time of the echo contrast medium from a mean of 14 s to 5 s (p < 0.001). The isovolumetric relaxation was shortened by 13% (p < 0.05), the E wave by 5%, and dp/dtmin increased by 17% (p < 0.01). In summary, intracoronary application of enoximone led to an improvement in both systolic and diastolic LV function without concomitant peripheral effect due to regression of myocardial ischemia.
 ...
PMID:[Acute effects of enoximone after intracoronary administration on hemodynamics, myocardial perfusion and regional wall motion]. 906 48

Transmembrane, voltage sensitive fluorescent dye (TMF) recording techniques have shown that high voltage shocks (HVS), typically used in defibrillation, produce either hyper- or depolarization of the transmembrane potential (TMP) when delivered in the refractory period of an action potential (AP) in normal cardiac tissue (NT). Further, HVS produce an extension of the AP, which has been hypothesized as a potential mechanism for electrical defibrillation. We examined whether HVS modify TMP of ischemic tissue (IT) in a similar manner. In seven Langendorff rabbit hearts, recordings of APs were obtained in both NT and IT with TMF using di-4-ANEPPS, and diacetylmonoxime (23 microM) to avoid motion artifacts. Local ischemia was produced by occlusion of the LAD, HVS of either biphasic (5 + 5 ms) or (3 + 2 ms) or monophasic shapes (5 ms) were delivered at varying times (20%-90%) of the paced AP. Intracardiac ECG and TMF recordings of the TMP were each amplified, recorded, and digitized at a frequency of 1 kHz. The paced AP in IT was triangular in shape with no obvious phase 3 plateau, typically seen in NT. There was normally a reduced AP amplitude (expressed as fractional fluorescence) in IT (2.6% +/- 1.79%) compared to 3.8% +/- 0.66% in NT, and shortened AP duration (137 +/- 42 vs 171 +/- 11 ms). One hundred-Volt HVS delivered during the refractory period of paced AP in IT in five rabbits, elicited a depolarization response of the TMP with an amplitude up to three times greater than the paced AP. This is in contrast to NT where the 100-V HVS produced hyperpolarization in four hearts, and only a slight depolarization response in one heart. These results suggest that HVS, typically delivered by a defibrillation shock, modify TMPs in a significantly different manner for ischemic cells, which may influence success in defibrillation.
 ...
PMID:Transmembrane potentials during high voltage shocks in ischemic cardiac tissue. 912 79

Local drug delivery at the lesion site in patients with coronary artery disease is being intensively studied to prevent restenosis after percutaneous coronary intervention. However, the effective penetration of the delivered agents into the vessel wall and delivery time remain considerable problems for all currently existing devices. A unique, new catheter has been invented, the infiltrator Angioplasty Balloon Catheter (IABC), which has the capability to allow intramural drug delivery by direct injection within the arterial wall. We describe the first clinical experience with this catheter. IABC is an angioplasty catheter with 3 lumens: one for inflating the balloon, one central for the guidewire, and a third for drug delivery. On the surface of the balloon there are 3 longitudinal strips of 6 injection needles, which on inflation stand 0.01" high, and are connected to the drug-delivery lumen. With inflation of the balloon, the needles penetrate the lesion, allowing drug delivery into the media of the vessel wall. We used the IABC in 17 patients (age = 58 +/- 9 years) undergoing coronary angioplasty. All patients were symptomatic, with significant lesions (13 LAD, 3 LCX, 1 RCA) and documented ischemia. Following initial dilatation with a conventional angioplasty balloon (stenosis from 72 +/- 8% to 26 +/- 14%, P < 0.001), the IABC was used to infiltrate the lesion with 0.4 ml (6,000 IU) of low-molecular-weight heparin (Fraxiparine). For the delivery, the IABC was inflated to 1-2 atm for 30-45 s, and the heparin was injected by hand in 5 s. Lesion residual stenosis and morphology remained unchanged after IABC use (26 +/- 14% to 22 +/- 11%, P = NS). In 10 patients, stent placement followed the IABC use. The decision to proceed with stent placement was made after the initial dilatation with the conventional balloon, and it was not influenced by the IABC use. Stent placement greatly improved the final result (for the whole patient group: 22 +/- 11% to 5 +/- 18%, for the stented patients: 22 +/- 13% to -7 +/- 10%, P < 0.001 for both). Hospital course was uneventful, with no electrocardiogram changes and normal cardiac enzymes for all patients. We have shown that the use of a unique new catheter (IABC) for intramural drug delivery in human patients undergoing coronary angioplasty is feasible and safe. This catheter is the first of a new generation of catheters and represents a significant step in local drug delivery. It is very promising as a vehicle to modify plaque behavior and potentially influence restenosis after angioplasty.
 ...
PMID:Intramural drug delivery by direct injection within the arterial wall: first clinical experience with a novel intracoronary delivery-infiltrator system. 921 27

Previous studies have demonstrated that a crude extract from Chinese medicinal herb Andrographis Paniculata Nees (APN) could prevent myocardial ischemia and reperfusion injury. A refined extract API0134 was studied further. LAD was ligated for 90 min in 20 dogs and then reperfused for 120 min. The animals were randomly divided into 2 groups, API0134 treated group (n = 10), 45 min after ischemia receiving a slow i.v. bolus of 1 mg/kg and then an infusion of 80 micrograms.kg-1/min for 60 min and control group (n = 10) which was given only 5% glucose in saline. Result showed that the hemodynamics in API0134 treated group showed better effects of preventing the increase of the LVEDP and maintaining relatively normal CO as compared with control group. Ischemic ECGs were significantly milder. Malignant arrhythmia did not appear in API0134 treated group. After reperfusion, the infarct size was smaller (5.06 +/- 2.67% vs 10.45 +/- 3.11%, P < 0.01), the damages found in myocardial ultrastructure were significantly milder. It is concluded that API0134 may protect the myocardium from ischemic reperfusion injury.
 ...
PMID:Protective effects of API0134 on myocardial ischemia and reperfusion injury. 938 78

The role of adrenergic mechanism in the cardioprotective effect of ischemic preconditioning against ischemia-reperfusion induced injury in in vivo dog heart and isolated rat heart was investigated. Anesthetized dogs were subjected to LAD coronary artery ligation for 60 min followed by reperfusion for 4 h. Preconditioning protocol was 5 min of ischemia followed by reperfusion for 10 min. Rat hearts were subjected to global ischemia for 30 min followed by reperfusion for 30 min. Preconditioning protocol was 5 min global ischemia followed by reperfusion for 5 min repeated four times. Infarct size, electrocardiographic changes and release of LDH were estimated to assess the extent of cardiac injury. Preconditioning reduced the infarct size, ST segment elevation and prevented the loss of R wave. Prazosin attenuated the cardioprotective effect of preconditioning in dog. Preconditioning conferred protection against ischemia-reperfusion induced cardiac injury and reperfusion-induced arrhythmias in isolated rat heart. Reserpine pretreatment attenuated this protective effect of preconditioning on reperfusion-induced arrhythmias. These observations suggest the involvement of adrenergic mechanism in the cardioprotective and antiarrhythmic effect of ischemic preconditioning in dog and rat species respectively.
 ...
PMID:The possible role of adrenergic component in ischemic preconditioning. 941 33


<< Previous 1 2 3 4 5 6 7 8 9 10