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PubMed1982

Effect of calcium concentration on collateral arteries from the hind limb of the dog.

Changes in extracellular calcium on collateral arteries were compared with noncollateral branch arteries from the normotensive extremity. Six weeks and 4 months after occlusion of the right superficial femoral artery, a collateral, a segment of branch artery from the opposite extremity and both anterior tibial arteries were removed. Exposure to calcium-free medium rapidly decreased the response of developing collaterals to l-epinephrine (10(-6) M) and initially increased the response by branch arteries. The fast response, dependent on intracellular calcium stores, decreased in collaterals but increased in branch arteries up to 40 min in calcium-free medium. The slow response, which is dependent on extracellular calcium, could not be sustained. Developing collateral and branch arteries responded similarly to [Ca++] 0.2 to 6.0 mM. Fast and slow components were unaffected in developing collaterals by calcium concentration. Fully developed collaterals were more sensitive to the effects of calcium depletion and to high and low calcium concentrations than developing collateral arteries. To evaluate the role of hypotension, anterior tibial arteries exposed to low blood pressure were compared with contralateral normal anterior tibial arteries. No differences were observed at 6 weeks or 4 months. The role of calcium in the response of developing collateral arteries differs from that in similarly sized branch arteries. These differences are not due to the pressure differential.

Aging↗
PubMed1996

Endothelium-dependent vasodilation in well-developed coronary collateral vessels.

We examined endothelium-dependent vasodilator responses in well-developed coronary collateral vessels. Collateral vessels and size-matched normal epicardial coronary arteries were isolated from canine hearts 6 months after a hollow plug had been introduced into the left anterior descending coronary artery (LAD) to stimulate collateral vessel growth. Vessel segments were isolated and studied in organ chambers. After preconstriction with prostaglandin F2 alpha, (PGF2 alpha) responses to the endothelium-dependent vasodilators, acetylcholine (ACh), substance P, and bradykinin (BK), as well as the endothelium-independent vasodilator nitroglycerin (NTG), were measured. The maximum relaxation to ACh was greater in collateral vessels (129 +/- 3.6% of the preconstricted tension) than in normal vessels (110 +/- 6.2%, p < 0.001), although the EC50 value for ACh was not significantly different between collateral and normal vessels. Collateral vessels demonstrated sensitivity to BK similar to that of normal vessels, but the maximal vasodilation achieved was greater in collaterals (138 +/- 4.6% of preconstricted tension) than in normal vessels (108 +/- 5.0%, p < 0.05). Both substance P and NTG produced dose-related relaxation that was similar in collateral vessels and normal arteries. These findings demonstrate that endothelium-dependent relaxation is intact in well-developed coronary collateral vessels.

Acetylcholine↗
PubMed1994

Preferential dilation of recipient coronary arteries of the collateral circulation by intracoronary administration of nitroglycerin.

OBJECTIVES: The purpose of this study was to test the hypothesis that the sensitivity to nitroglycerin of collateral vessels and recipient arteries is greater than that of donor arteries of the collateral circulation. BACKGROUND: The collateral circulation responds vigorously to nitroglycerin. However, the mechanisms of the efficacy of nitroglycerin for improving collateral circulation are not fully elucidated. METHODS: The diameter of donor and recipient arteries of the collateral circulation was measured with a computer-assisted analysis system in eight patients with well developed collateral vessels. Coronary angiography was repeated before and after the intracoronary injection of 50 micrograms of nitroglycerin. RESULTS: After nitroglycerin, the mean diameter +/- SD of donor arteries increased to 1.61 +/- 0.53 from 1.29 +/- 0.39 mm (p < 0.01), whereas the diameter of recipient arteries increased to 1.59 +/- 0.50 from 1.10 +/- 0.49 mm (p < 0.01). The change in the diameter of recipient arteries was significantly greater than that of donor arteries (52.3 +/- 24.6% vs. 24.7 +/- 11.5%, p < 0.05). These changes induced by the intracoronary injection of nitroglycerin were accompanied by a decrease in pacing-induced ST segment depression (0.16 +/- 0.06 to 0.06 +/- 0.04 mV, p < 0.01), suggesting increased flow reserve through collateral channels. CONCLUSIONS: These findings indicate that the sensitivity to nitroglycerin of recipient arteries of the collateral circulation is significantly greater than that of donor arteries. This observation may explain the strong response of the collateral circulation to nitroglycerin in patients with functionally significant collateral channels.

Aged↗
PubMed2001

Washout collaterometry: a new method of assessing collaterals using angiographic contrast clearance during coronary occlusion.

OBJECTIVE: To investigate the hypothesis that the time to washout of radiographic contrast medium trapped distal to an occluded collateral receiving vessel is inversely related to collateral flow, and that this provides an accurate method for characterising coronary collaterals. METHODS: An intracoronary pressure derived collateral flow index was determined in 54 patients undergoing percutaneous transluminal coronary balloon angioplasty (PTCA). The study group was subdivided according to whether the collateral vessels were sufficient (n = 17) or insufficient (n = 37) to prevent ECG signs of myocardial ischaemia during PTCA. Washout collaterometry-an angiographic washout method-was carried out simultaneously; after injection of radiographic contrast medium into the collateral receiving vessel followed immediately by vascular occlusion, the number of heart beats was counted until approximately half the length of the epicardial vessel was cleared of contrast. RESULTS: The collateral flow index was higher (0.28 (0.09) v 0.12 (0.07); p < 0.0001) and the contrast washout time shorter (8.0 (2.9) v 17.5 (6.7) heart beats; p < 0.0001) in patients with sufficient versus insufficient collaterals. There was an inverse correlation between contrast washout time and collateral flow index (r = 0.72, p < 0.0001). Washout of contrast distal to the occluded vessel within 11 heart beats correctly determined sufficient and insufficient collaterals with 88% sensitivity and 81% specificity. CONCLUSIONS: Washout collaterometry is a new radiographic contrast washout method based on the inverse relation between collateral flow and the time to clearance of radiographic dye injected into the ipsilateral vessel during PTCA. It appears to be an accurate method of characterising coronary collateral vessels.

Angioplasty, Balloon, Coronary↗
PubMed2006

Power Doppler endoscopic ultrasonography for the differential diagnosis between pancreatic cancer and pseudotumoral chronic pancreatitis.

OBJECTIVE: The accuracy of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration for the differential diagnosis of pancreatic masses is variable in the literature, being as low as 75% in some studies. The aim of the study was to assess the accuracy of power Doppler EUS for the differential diagnosis between pancreatic cancer and pseudotumoral chronic pancreatitis. METHODS: We included 42 consecutive patients with pancreatic tumor masses (27 men and 15 women) examined by EUS between January 2002 and August 2004. Endoscopic ultrasonographic procedures included power Doppler EUS as well as EUS-guided fine-needle aspiration in all patients. Final diagnosis of pancreatic cancer was confirmed in 29 patients on the basis of a combination of information provided by imaging tests, follow-up of at least 6 months, and laparotomy in 18 patients for diagnostic or palliative reasons. RESULTS: Sensitivity and specificity of the absence of power Doppler signals inside the suggestive pancreatic mass were 93% and 77%, respectively, with accuracy of 88%. Moreover, the addition of the information provided by the presence of peripancreatic collaterals improved the sensitivity and specificity to 97% and 92%, with accuracy of 95%. CONCLUSIONS: Power Doppler EUS provides useful information for the differential diagnosis of pancreatic masses. The results were in concordance with previous studies that showed a hypovascular pattern of pancreatic carcinoma, as well as the formation of collaterals in advanced cases due to the invasion of the splenic or portal veins. Further studies of dynamic EUS with contrast agents are necessary to better characterize pancreatic masses.

Adult↗
PubMed1995

Role of collateral flow in a pharmacological stress test (a combination of low-dose dobutamine and a vasodilator) as a predictor of wall motion reversibility.

The role of collateral flow was evaluated in a pharmacological stress test [a combination of low-dose dobutamine (DOB) and a vasodilator] as a predictor of wall motion reversibility at rest after percutaneous transluminal coronary angioplasty (PTCA) using ultrafast computed tomography (UFCT). Segments with wall motion abnormalities before PTCA were divided into two groups; ie, either with or without collateral flow. Patients were scanned at rest for baseline and again after 5 min of intravenous administration of 4 micrograms/kg per min of DOB after nitroglycerin (0.3 mg sublingually) or isosorbide dinitrate (2.5 mg bolus intravenous injection). Three months after PTCA, patients were scanned again and wall motion was compared with the previous findings. In collateral-dependent segments, the sensitivity of the pharmacological stress test as a predictor of wall motion reversibility was 87.5% and the specificity was 83.3%. In collateral-independent segments, the sensitivity was only 41.7%, while the specificity was 95.2%. Our findings demonstrate that the pharmacological stress test we used satisfactorily predicted wall motion reversibility in collateral-dependent segments, but tended to underestimate wall motion reversibility in collateral-independent segments. Therefore, collateral flow may be an important factor in accurately predicting wall motion reversibility by this pharmacological stress test.

Adolescent↗
PubMedDate not supplied

Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation.

A prospective study was completed on 25 baseball players with medial side elbow pain. They were evaluated preoperatively with both computed tomography arthrogram and magnetic resonance imaging examinations of the elbow to assess the ulnar collateral ligament. At surgery, 16 of 25 patients had an abnormal ulnar collateral ligament and 9 patients had a normal ulnar collateral ligament. The computed tomography arthrogram detected abnormalities in 12 of the 14 patients with ulnar collateral ligament tearing (sensitivity, 86%). The magnetic resonance imaging scan indicated abnormalities in 8 of 14 patients (sensitivity, 57%). The specificity of the computed tomography arthrogram was 91% and the magnetic resonance imaging was 100%. A newly described "T-sign" was seen on the computed tomography arthrogram in the patients with an undersurface tear of the ulnar collateral ligament. This represented the dye leaking around the detachment of the ulnar collateral ligament from its bony insertion but remaining contained within the intact superficial layer of the ulnar collateral ligament and capsule. Both the computed tomography arthrogram and the magnetic resonance imaging scan were accurate in diagnosing a complete tear of the ulnar collateral ligament preoperatively in all cases. The main advantage of the computed tomography arthrogram was in evaluating the partial undersurface tear.

Adolescent↗
PubMed1975

Pharmacoangiographic evaluation of the hemodynamic significance of coronary artery stenoses.

Acute stenoses of varying degree were produced in the circumflex arteries of 5 calves, and chronic stenoses which reduced blood flow by about 50% were effected in the left anterior descending coronary arteries of 14 dogs. Selective vasodilators or amyl nitrite increased blood flow more than 100% in nonstenotic arteries, but less in stenotic ones. Increased transstenotic blood flow was associated with an increased pressure gradient and increased frequency of collateral circulation. Collateral circulation was sometimes recognizable when the pre- and postvasodilatory angiograms were compared but not when the angiograms were examined individually. The altered flow patterns demonstrated by comparative studies may be a very sensitive index of collateral circulation.

Adenosine↗
PubMed1990

[Assessment of infarct-related coronary arteries using the bull's eye view method and unfolded surface mapping in thallium-201 myocardial tomography].

Infarct-related coronary lesions and collaterals were assessed by the bull's eye view and the unfolded surface map derived from thallium-201 myocardial tomography (Tl-201 SPECT) in 25 patients with anterior myocardial infarction. The patients were categorized in six groups according to their cine-angiographic findings: locations of stenosis (proximal or distal portions of the first diagonal branch or distal site of the first septal branch), and the presence or absence of collaterals. The anterior half of the left ventricle on the bull's eye view map was divided into eight regions from the anterior septum to the lateral wall and from the apex to the cardiac base. Tl-201 SPECT images were expressed as functional maps using maximum-count circumferential profile analysis: an "extent image" showing the extent of perfusion defect, and a "severity image" demonstrating the degree of hypoperfusion. The following results were obtained: 1. Perfusion defect of the "extent image" at the basal portion of the anterior septum reflected poor collaterals, with a sensitivity of 81.3%, a specificity of 77.8%, and a diagnostic accuracy of 80.0%. 2. Coronary stenosis at segment 6 (AHA classification) was differentiated from that at segment 7 by detecting hypoperfusion at the basal septum on the "severity image", with a sensitivity of 71.4%, a specificity of 77.8%, and a diagnostic accuracy of 75.0%. 3. Perfusion defect at the basal section of the proximal portion of the anterior wall on the "extent image" indicated stenosis at the proximal segment 6, with a sensitivity of 57.1% and a specificity of 88.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Transcatheter hepatocyte transplantation: preclinical studies of anatomic consequences in the portal vascular bed.

RATIONALE AND OBJECTIVES: Intrasplenic transplantation deposits hepatocytes in host hepatic sinusoids with amelioration of chronic liver failure and genetic deficiency states. Because portal resistance can be altered by intrasinusoidal transplanted cells, we examined whether hepatocyte recipients would develop deleterious portal hypertension or portosystemic collaterals. METHODS: Syngeneic hepatocytes in suspension were transplanted into recipient rats by transcatheter injection into the splenic parenchyma. Subjects included recipients of 2 x 10(7) hepatocytes representing approximately 3% of the host hepatic mass, recipients of 7.5 x 10(7) hepatocytes representing approximately 12.5% of the host hepatic mass, normal control rats, and positive control rats with portal hypertension induced by partial portal vein constriction. Portal pressures were recorded with a sensitive transducer, portosystemic collaterals were demonstrated with direct splenoportography, and survival of transplanted cells was determined with an endogenous dipeptidyl peptidase IV reporter gene. RESULTS: In normal rats, the portal pressure was 6.25 +/- 1.9 mm Hg with no portosystemic collaterals. By contrast, portal pressures were significantly increased in portal vein-constricted rats, 20.7 +/- 3.9 mm Hg (P < 0.001), with extensive portosystemic collaterals. In hepatocyte recipients, portal hypertension observed during transcatheter cell injection but proved transient. When animals were examined up to 16 weeks after hepatocyte transplantation, portal pressures were in the normal range (after 2 x 10(7) cells, 7.5 x 2.6 mm Hg; after 7.5 x 10(7) cells, 9.5 +/- 4.2 mm Hg, P = not significant). No portosystemic collaterals developed in hepatocyte recipients at various times up to 8 months after transplantation. Transplanted hepatocytes expressing the reporter gene were present in recipients with assimilation in host hepatic cords. CONCLUSION: Despite injection of a massive number of cells, transcatheter hepatocyte transplantation was devoid of any significant portal vascular alterations or toxicity in recipients. These findings are consistent with assimilation of transplanted hepatocytes into host hepatic cords and will facilitate therapeutic applications in metabolic diseases or acute liver failure.

Animals↗
PubMed2003

Physical examination of the knee: a review of the original test description and scientific validity of common orthopedic tests.

OBJECTIVES: To present the original descriptions of common orthopedic physical examination maneuvers of the knee and then to review the literature to support the scientific validity of these tests. DATA SOURCES: MEDLINE (1970-2000) searches were performed, as were reviews of various musculoskeletal examination textbooks that describe physical examination maneuvers of the knee. These references were then reviewed for additional references and crossed back to the original description (when possible) of these named tests. STUDY SELECTION: All articles that discussed the sensitivity and specificity of the physical examination maneuvers were extracted. This information was reviewed for accuracy and then summarized. DATA EXTRACTION: Multiple MEDLINE and text searches were performed by using the terms of the test maneuver, the joint tested, and the term physical examination. Any article with this information was reviewed until the article describing the original description was found. Articles dating from that original article to the present were reviewed for information on the sensitivity and specificity of the test. DATA SYNTHESIS: Literature reviewing the sensitivity and specificity of the tests reviewed is summarized in text and table form. The Lachman test seems to be very sensitive and specific for the detection of anterior cruciate ligament tears. For posterior cruciate ligament tears, the posterior drawer test is also very sensitive and specific and is enhanced with other tests, such as the posterior sag sign. For meniscal tears, the McMurray test is very specific but has a very low sensitivity, whereas joint line tenderness has fairly good sensitivity but lacks good specificity. Although collateral ligament testing seems to be sensitive and specific, there is a lack of well-designed studies that scientifically validate the sensitivity and specificity of these tests. Common tests for patellofemoral pain and patellar instability lack sensitivity when correlated with pathologic operative findings. CONCLUSIONS: Most physical examination tests could be referenced back to an original description, with variable information on the sensitivity and specificity along with other information about the validity of these tests in clinical practice. To standardize how physical examinations are performed and compared, they should follow the original description or agreed-on standards. In addition, the significance of a physical examination finding must be understood to ensure that patients with knee complaints are accurately diagnosed and properly treated.

Biomechanical Phenomena↗
PubMed1996

Are the major effects of P-glycoprotein modulators due to altered pharmacokinetics of anticancer drugs?

Agents (modulators) that reverse the in vitro resistance of tumor cells to anticancer drugs that are substrates for P-glycoprotein (Pgp, the product of the MDR1 gene) have been given to patients concurrently with anticancer drugs in an attempt to improve therapeutic response. The vast majority of investigations into these drugs indicate that Pgp modulators decrease the systemic clearance of anticancer drugs, thus potentially nonselectively increasing exposure to normal and malignant cells and thereby potentially increasing the severity and/or incidence of adverse effects associated with the anticancer therapy. Mechanisms by which Pgp modulators could alter the pharmacokinetics of the anticancer agent include competition for cytochrome P450 intestinal or liver metabolism, inhibition of Pgp-mediated biliary excretion or intestinal transport, or inhibition of renal elimination. It is suggested that administration of Pgp modulators is unlikely to improve the therapeutic index for anticancer drugs unless agents that lack significant pharmacokinetic interactions are found. Moreover, it will likely be required that there be some cancer-tissue selectivity for modulators in order to avoid collaterally increasing the sensitivity of normal Pgp-expressing tissues to the anticancer drug.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Prior collateral sprouting of sensory axons delays recovery of pain sensitivity after subsequent nerve crush.

Regeneration of motor axons is enhanced if they have sprouted prior to nerve injury. We examined whether sensory axon regeneration and recovery of pain response was affected by previous collateral sprouting. In the experimental group of rats, the right saphenous, tibial, and sural nerves were transected and ligated. The peroneal nerve was left to sprout into the adjacent denervated skin. Two months later, the axons of the peroneal nerve were crushed in the sciatic nerve. In the control group, the right sciatic nerve was crushed at the same time that the saphenous, tibial, and sural nerves were transected. Recovery of pain response in the foot was determined by the skin pinch test. Sensory axon elongation rate was measured by the nerve pinch test. The number of myelinated axons was determined in nerve cross sections stained by Azur blue. Recovery of pain sensitivity in the animals of the experimental group was delayed for 2-3 weeks in comparison to the control group. Moreover, the spatial pattern of pain response in the experimental group was irregular, displaying residual regions of insensitive skin which were not present in controls. The elongation rate of regenerating sensory axons in the experimental group was not decreased, and the number of myelinated axons in the peroneal nerves was even about 10% higher than in the control group. Therefore, we assume that the terminal arborization of the neurilemmal tubes pertaining to the former axon sprouts delayed regrowth of sensory axon terminals in the skin.

Animals↗
PubMed1996

Functional mapping of color processing by magnetic resonance imaging of responses to selective P- and M-pathway stimulation.

Magnetic resonance imaging sensitized to activity-related changes in cerebral blood oxygenation was performed to map responses to selective stimulation of the parvo- and magnocellular visual pathways in calcarine and adjacent ventral occipital cortex of human subjects. In a repetitive stimulation protocol isoluminant chromatic or isochromatic luminance modulation was alternated with steady light of the same mean chromaticity and luminance as a reference condition. While no significant effects were observed for diffuse luminance modulation, two consistent cortical foci responded to isoluminant chromatic stimulation. A strong response was obtained in calcarine cortex at both 2 and 10 Hz, and even for selective S-cone stimulation. A second weaker color-sensitive response was seen bilaterally in the collateral sulcus. Thus, the data not only confirm color-sensitive activation in the collateral sulcus elicited in previous studies by selective cognitive tasks, but additionally demonstrate color-sensitive activation in primary visual cortex. With stimuli defined according to electrophysiological response properties of early visual processing stages, this study complements phenomenological or cognitive approaches in functional mapping of the human visual system.

Adult↗
PubMed1988

Effect of age on collateral reinnervation of sweat glands in the mouse.

This study demonstrates that the number of sweat glands (SGs) innervated by individual peripheral nerves in the mouse hind paw decreases with aging but the ability for reinnervation by collateral sprouting is maintained throughout life. In one experiment, the saphenous, peroneal and tibial nerves were cut and tied, denervating all SGs of the hind paw except those receiving axons from the intact sural nerve. In another, the saphenous was the only nerve left intact. The initial number of SGs supplied only by the single intact nerve was significantly higher in young adult than older mice. The capacity of the sural and saphenous nerves to collaterally reinnervate the denervated SGs was followed by serial testing for the return of sensitivity to pilocarpine stimulation. Collaterally reinnervated SGs appeared during the second and third weeks postoperation adjacent to already active SGs, thereby increasing the total sweat area of the intact nerve, and its SG number about 3, 2 and 5 times for the sural, and 8, 2 and 2 times for saphenous nerve, in young, adult and old animals respectively. Reinnervation was slightly faster and the degree of extension greater in young than adult mice, and the degree of extension was decreased in older mice. These observations suggest that the number of sudomotor axons in the peripheral nerve, as well as their capacity for collateral reinnervation, is reduced with aging.

Aging↗
PubMed1988

Determinants and protective potential of coronary arterial collaterals as assessed by an angioplasty model.

Two indexes of collateral blood flow, the ratio of distal coronary occlusion pressure/aortic pressure (DCOP/Pao) and angiographic collateral class were determined during elective angioplasty in 36 patients with normal left ventricular function. The association between collateral indexes and 8 anatomic and clinical variables was assessed. A reduction in luminal diameter by greater than or equal to 70% predicted angiographically demonstrable collaterals with 100% specificity and 85% sensitivity. Lesion severity (stenosis) correlated with both collateral class and DCOP/Pao: DCOP/Pao = 2.8809 - 0.0729 X stenosis + 0.00049 X stenosis. The data suggest a quantitative relation between lesion severity and collateral development beyond a threshold value of 70% stenosis. Left ventricular ejection fraction during ischemia caused by balloon occlusion (EFo) was found to be primarily determined by lesion location; however, collateral flow modified EFo significantly. For mid-left anterior descending and right coronary artery: EFo = 59 + 26 X (DCOP/Pao); for proximal left anterior descending artery: EFo = 24 + 89 X (DCOP/Pao). A model predicting the hemodynamic and clinical consequences of abrupt coronary closure based on lesion location and severity was developed. In the second study phase, this model was tested retrospectively in a different group of 23 patients who experienced coronary occlusion as a complication of angioplasty. The data of both study phases suggest that left ventricular function and clinical outcome after abrupt coronary closure are determined by an interaction between location of the coronary artery obstruction and the amount of collateral flow. Lesion severity and the extent of functional impairment resulting from abrupt coronary closure are inversely related.

Angioplasty, Balloon↗
PubMed1994

Myocardial viability in asynergic regions subtended by occluded coronary arteries: relation to the status of collateral flow in patients with chronic coronary artery disease.

OBJECTIVES: This study aimed to determine whether angiographically visualized collateral vessels in patients with chronic coronary artery disease imply the presence of viable myocardium in asynergic regions subtended by completely occluded coronary arteries. BACKGROUND: Patients with chronic coronary artery disease who are being considered for revascularization frequently exhibit angiographically visualized collateral vessels to completely occluded coronary arteries supplying severely asynergic myocardial regions. However, little is known about the relation between angiographic collateral flow and myocardial viability in these patients. METHODS: We studied 42 patients with 78 completely occluded coronary arteries supplying asynergic territories. Angiographic collateral vessels were interpreted as absent (grade 1) in 14 patients, minimal (grade 2) in 27 and well developed (grade 3) in 37. Myocardial viability was determined with positron emission tomography using nitrogen-13 (N-13) ammonia and fluorine-18 (F-18) deoxyglucose for assessment of regional perfusion and glucose uptake, respectively. Positron emission tomographic patterns were interpreted as mismatch (perfusion defect with enhanced F-18 deoxyglucose uptake); transmural match (severe concordant reduction or absence of both perfusion and F-18 deoxyglucose uptake) or nontransmural match (mild to moderate concordant reduction of both perfusion and F-18 deoxyglucose uptake). RESULTS: There was no significant correlation (p = 0.14) between the severity of perfusion deficit assessed by positron emission tomography and the collateral grade. The extent of mismatch was unrelated to either the presence or the magnitude of collateral vessels. Conversely, with increasing collateral vessels from grade 1 to 3, the total extent of positron emission tomographic match remained similar, whereas the ratio of transmural to nontransmural match decreased. Myocardial viability was usually present in severely hypokinetic regions (82%). It was lower in akinetic-dyskinetic regions (49%). Of the 64 regions with angiographic collateral vessels, 37 (58%) (95% confidence interval [CI] 46% to 70%) showed positron emission tomographic mismatch. In contrast, 7 (50%) of 14 (95% CI 24% to 76%) regions without collateral vessels on angiography exhibited positron emission tomographic mismatch. The presence of angiographically visualized collateral vessels was a sensitive (84%) but not specific (21%) marker of viability. CONCLUSIONS: In patients with chronic coronary artery disease, angiographically visualized collateral vessels to asynergic myocardial regions subtended by occluded coronary arteries do not always imply the presence of viable myocardium, suggesting that revascularization may not always provide a functional benefit.

Adult↗
PubMed2001

[The diagnostic value and limitations of total serum bile acid determined enzymatically].

OBJECTIVE: To elucidate the diagnostic value of total serum bile acid. METHOD: Clinical data from 913 cases was statistically analyzed with SPSS for Windows and other statistical procedures reported previously. RESULTS: (1) The mean of TBA of healthy subjects was (4.0 +/- 3.2) micromol/L. The TBA level of liver disease group is significantly higher than other group(P < 0.01). (2) The mean of TBA of patients with acute hepatitis was (167.2 +/- 132.4) micromol/L, the highest value was 449.5 micromol/L, it was significantly higher than other groups. TBA was a sensitive mark reflecting acute hepatic injury. (3) The sensitivity of TBA in patients with cirrhosis was 85.8%, higher than routine liver function tests. TBA is a valuable mark reflecting collateral circulation. (4) The sensitivity of TBA in mild chronic hepatitis was only 30.5%, much lower than ALT and TBIL (P < 0.01). (4) There was a relationship between the level of TBA and the severity of patients' condition, but the value of TBA for evaluating the severity was not as good as TBIL. CONCLUSION: The specificity of TBA is quite high, the sensitivity is moderate, TBA is valuable for the diagnosis of liver disease, especially for acute hepatitis and cirrhosis, but it's sensitivity for mild chronic hepatitis is only 30.5%, it is not as good as TBIL for evaluating the condition of patients.

Acute Disease↗