Biomedical subjects

J M Kioschos

Publications and source records attributed to J M Kioschos.

At least 19 recordsLinked to original sources

PubMed1996

A critical analysis of cerebral computed tomography scanning before elective carotid endarterectomy and its correlation to carotid stenosis.

BACKGROUND: Cerebral computed tomography (CT) scanning has been suggested to play a role in the management of patients before carotid endarterectomy (CEA). This prospective study analyzes the value of CT scanning before elective CEA and the correlation of CT findings to significant carotid stenosis. METHODS: This study includes 131 consecutive patients considered for CEA during a 2-year period. All patients underwent carotid duplex ultrasonography, carotid arteriography, and CT scanning. RESULTS: Eighty patients (61%) had transient ischemic attacks or prior strokes, and 51 (39%) had nonhemispheric symptoms or were asymptomatic. The CT scan was abnormal in 36 (27%) patients; however, no brain tumors or abnormalities to affect clinical management were revealed. Ninety-two CEAs were performed on 87 patients. Twenty-nine (32%) in the operative group had abnormal CT scans, but these did not influence operative decisions. On the basis of this rate of 0% of patients with CT findings to change surgical management in 92 cases, a maximum true rate of occurrence of up to 5% could be detected with alpha equals 0.05 by sampling a population of this size. Four patients (4%) had postoperative cerebral vascular accidents, and all of these had normal preoperative scans. Patients with 50% or more carotid stenosis on arteriogram were significantly more likely to have abnormal CT scans than patients with less than 50% stenosis (20% versus 7%, p = 0.0034). As carotid stenosis became more significant, the frequency of abnormal CT scans increased (p < 0.01). The cost of CT scanning was $66,089.50 in this study. CONCLUSIONS: Significant carotid stenosis was associated with a higher frequency of abnormal CT scans; however, routine preoperative CT scanning was unnecessary before elective CEA.

Adult↗

PubMed1994

Presentation of a horse cytochrome c peptide by multiple H-2b class I major histocompatibility complex (MHC) molecules to C57BL/6- and bm1-derived cytotoxic T lymphocytes: presence of a single MHC anchor residue may confer efficient peptide-specific CTL recognition.

In this study the immunogenic tryptic fragment from a horse cytochrome c (cyt c) digest recognized by cytotoxic T lymphocytes (CTL) induced by in vitro peptide stimulation from C57BL/6 (B6) and mutant B6.C-H-2bm1 (bm1) mice is identified. An identical sequence, p40-53, is recognized by CTL from both B6 and bm1 mice. In addition, both B6 bm1 cloned CTL lines display unusual major histocompatibility complex (MHC) class I-restricted recognition of this peptide in that they respond to it in the context of H-2Kb, H-2Db, and H-2Kbm1 class I molecules, although the sequence lacks the usual structural Kb and Db peptide-binding motifs. Truncated analogues which resemble the lengths of naturally processed MHC class I-presented peptides, confer reactivity for B6 and bm1 CTL against EL4 (H-2b) targets as well as the L cell transfectants, L+Kb, L+Db, and L+Kbm1. The antigenic peptide with the greatest potency is p41-49, which appears to be generated by angiotensin converting enzyme cleavage of the full-length p40-53 tryptic peptide. The minimum antigenic peptide recognized by both B6 and bm1 CTL, and which targets lysis on each of the transfectants, is the hexamer p43-48 peptide from horse cyt c. Residues Pro44 and Thr47, which occupy polymorphic positions with respect to other species-variant cyt c molecules, influence recognition of these peptides differently for the B6 and bm1 CTL. The ability of H-2Kb, H-2Db, and mutant H-2Kbm1 class I molecules to present the same peptide to a single cloned CTL is discussed in the context of current knowledge of peptide anchor residues and side chain-specific binding pockets in the MHC class I peptide-binding site.

Amino Acid Sequence↗

PubMed1987

The importance of the determination of the myocardial area at risk in the evaluation of the outcome of acute myocardial infarction in patients.

On the basis of animal studies, we postulated that the size of the perfusion field (risk area) of an occluded coronary artery would be an important determinant of outcome in patients with acute myocardial infarction. To test this hypothesis, we measured size of the risk area in 27 patients with acute myocardial infarction by the intracoronary injection of 99mTc-macroaggregated albumin and gated nuclear imaging. After injection of the albumin spheres (5.3 +/- 1.4 hr after the onset of chest pain) streptokinase was administered and in 16 of 27 patients (59%) effective thrombolysis was achieved. Since none of the patients had evidence of a prior acute myocardial infarction, the 3 day nuclear left ventricular ejection fraction (LVEF) was considered an index of infarct size. Response to thrombolysis was analyzed according to success or failure of reperfusion and the size of the risk area (small risk area less than 25%, large risk area greater than 25% of left ventricular surface area). Standard clinical indexes correlated poorly with size of the risk area: electrocardiographic variables (r = .37), left ventricular end-diastolic pressure (r = .23), cardiac index (r = .55), and the LVEF obtained from a right anterior oblique contrast ventriculogram (r = .31). The coronary vessel responsible for the acute myocardial infarction significantly influenced size of the risk area (left anterior descending, 38 +/- 5% [mean +/- SD] vs circumflex or right coronary artery, 17 +/- 4%). However, knowledge of the site of coronary occlusion within a vessel was not helpful in predicting the size of the area at risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed1984

Influence of baseline ejection fraction and success of thrombolysis on mortality and ventricular function after acute myocardial infarction.

The efficacy of streptokinase (STK) thrombolytic therapy was prospectively evaluated in 77 consecutive patients presenting within 9 hours of onset of acute myocardial infarction. Serial left ventricular (LV) ejection fraction (EF) was assessed by radionuclide ventriculography, initially (acute) and at 1 month (late). The role of initial LVEF was examined by comparing patients with an acute LVEF greater than or equal to 50% (type I) with those with LVEF less than 50% (type II). Sixty-five patients (84%) had total coronary occlusion and received STK. Initial successful reperfusion was achieved in 34 patients (52%), but repeat angiograms at 10 to 14 days revealed persistent patency in only 27 patients. Within the type I and type II classification, 2 patient subgroups were compared: Group A had successful and persistent thrombolysis and group B had initial failure of thrombolysis or in-hospital reocclusion. There was no significant change in global LVEF in any group from acute to 1 month follow-up: group IA--acute EF = 56 +/- 2% (mean +/- standard error of the mean), late EF = 55 +/- 2% (p = not significant [NS]); group IB--acute EF = 58 +/- 1%, late EF = 55 +/- 2% (NS); group IIA--acute EF = 35 +/- 2%, late EF = 4 +/- 4%, (NS); group II B--acute EF = 36 +/- 2%, late EF = 41 +/- 3% (NS). No patient with an acute EF greater than or equal to 50% died, i.e., group IA patients (n = 7) or group IB patients (n = 13).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1984

Systemic markers of fibrinolysis after unsuccessful intracoronary streptokinase thrombolysis for acute myocardial infarction. Does nonreperfusion indicate failure to achieve a systemic lytic state?

Reasons for the failure of intracoronary streptokinase (STK) to result in coronary thrombolysis were examined in 45 patients with acute myocardial infarction presenting with angiographic evidence of total coronary occlusion. In 25 patients (group A), clot lysis was initially successful; in 20 (group B), reperfusion was unsuccessful. The STK dosage in group A ranged from 84,000 to 310,000 units (mean 188,000 +/- 12,000); STK dosage in group B ranged from 160,000 to 360,000 units (mean 267,000 +/- 11,000 [p less than 0.05]). Before therapy, levels of fibrin degradation products and serum fibrinogen were normal in all patients. After intracoronary STK, fibrin degradation products and serum fibrinogen levels changed similarly in both groups. Eight-five percent of patients in group B had evidence of a systemic fibrinolytic state. These data suggest that higher doses of STK administered in the same manner are unlikely to result in an increased reperfusion rate. Systemic hematologic markers of fibrinolysis are not helpful in explaining the success or failure of intracoronary thrombolysis.

Coronary Angiography↗

PubMed1984

Angiographic evidence that reciprocal ST-segment depression during acute myocardial infarction does not indicate remote ischemia: analysis of 23 patients.

Although reciprocal ST-segment depression from the remote noninfarcting ventricular wall during acute myocardial infarction (MI) is a common clinical finding, the significance of this electrocardiographic pattern is unclear. Previous retrospective studies have suggested that these findings may reflect either remote wall ischemia, multivessel coronary artery disease (CAD), extensive MI or a benign electrical phenomenon. Prior studies have lacked angiographic data obtained at the time of these acute electrocardiographic changes. In this study we prospectively evaluated 23 patients with acute MI. Left ventricular wall motion, coronary anatomy and the ECG were all assessed over a short period during the acute phase of the MI. Segmental wall motion was used as a sensitive indicator of ischemia. Seventeen patients had acute anterior MI, of whom 47% had reciprocal ST-segment depression; 6 patients had inferior MI, with 3 showing reciprocal ST depression. The mean degree of ST-segment elevation from the infarcting wall tended to be greater in patients with reciprocal ST-segment depression than in those without such reciprocal ST depression (2.8 +/- 0.4 vs 1.9 +/- 0.3 mm, p = 0.06). Patients with and without reciprocal ST-segment depression had similar degrees of segmental dysfunction in the infarct wall. However, no abnormalities in segmental wall motion in the remote wall were seen regardless of the presence or absence of remote wall ST-segment depression. In addition, the presence or absence of ST-segment depression did not predict the extent or degree of CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

Combined intracoronary streptokinase and percutaneous coronary angioplasty for reperfusion of chronic total coronary occlusion.

In a 40 year old man with a 1 month total occlusion of a dominant right coronary artery, persistent angina despite medical management indicated inadequate coronary collateral supply to the posterolateral myocardium originally supplied by the totally occluded vessel. Initial attempts at reperfusion of the chronically occluded vessel with an angioplasty guide wire and balloon were unsuccessful. However, administration of intracoronary streptokinase resulted in partial reperfusion, after which successful wire-guided balloon angioplasty was accomplished. This case illustrates the potential utility of combining a thrombolytic agent with angioplasty in attempting reperfusion for management of selected cases of chronic total coronary artery occlusion.

Adult↗

PubMed1984

Rethrombosis after reperfusion with streptokinase: importance of geometry of residual lesions.

We tested the hypothesis that lesion rethrombosis after streptokinase reperfusion is related to luminal size of the residual stenosis. Two independent techniques of analyzing coronary angiograms, quantitative coronary angiography and computer-based videodensitometry, were used to estimate the size of the residual lumen immediately after discontinuation of streptokinase. These techniques were selected because they provide independent estimates of cross-sectional area of a lesion with high degrees of reproducibility and minimal observer variability. Twenty-four patients who had undergone successful reperfusion with streptokinase were studied. Seven patients had lesion rethrombosis documented either on a repeat angiogram, at autopsy, or, in one case, by the fact that the patient had an acute transmural infarction resulting in death. Vessel patency was documented by repeat coronary angiography 8 to 14 days after initial streptokinase reperfusion in the other 17 patients. As assessed by quantitative coronary angiography, seven of 13 patients (54%) with minimal luminal cross-sectional areas of less than 0.4 mm2 had rethrombosis. None of the 11 patients with lumens greater than 0.4 mm2 had rethrombosis. In the 17 patients with vessels that remained patent the size of the residual lesion at repeat catheterization was compared with its size immediately after reperfusion with streptokinase. Over the intervening 8 to 14 day interval, an average percentage increase in minimal cross-sectional area of 116 +/- 34% was observed. In seven patients minimal luminal cross-sectional area more than doubled. Integrated optical density, an index of the severity of coronary stenosis derived from computer-based videodensitometry, was also useful in identifying a subgroup of patients at high risk for rethrombosis of lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗

PubMed1976

Primary angiosarcoma of the heart.

Primary hemangioendotheliosarcoma is the least common form of sarcoma of the heart, itself an uncommon tumor. A review of most of the reported cases is presented. This study revealed that although the syndrome produced by cardiac sarcoma point to a strikingly characteristic picture, the diagnosis is almost always confused, especially with pericardial inflammatory diseases, and delayed. Successful treatment generally has not been available. This is the only case we know of that has been treated by resection utilizing cardiopulmonary bypass. The appearance of metastases in unusual locations in our patient, despite total excision of the primary, suggests tumor embolization during the bypass and the need for intra-operative chemotherapy, as well as such treatment before or after surgery.

Adolescent↗

PubMed1976

Regression of atherosclerotic stenosing lesions of the renal arteries and spontaneous cure of systemic hypertension through control of hyperlipidemia.

We describe a 49 year old woman with impressive regression of renal artery stenosing atherosclerotic lesions in response to sustained excellent control of hyperlipidemia. Initially, she had high blood pressure necessitating combined drug therapy with chlorothiazide, methyldopa and propranolol, with only moderately satisfactory control. Renal arteriography revealed a 90 per cent stenosing lesion of the right renal artery and 75 per cent narrowing of the left renal artery. Peripheral vein plasma renin was markedly increased at 32 ng/ml. With a combination of cholestyramine and clofibrate, serum lipids were maintained at normal values for several years. Increased blood pressure diminished spontaneously, and the patient has maintained normal blood pressures after discontinuation of antihypertensive therapy. Repeat renal arteriograms showed almost complete regression of the right renal artery lesion and a possible decrease in left renal artery disease. Peripheral vein plasma renin became normal at 3 ng/ml. This case illustrates that sustained control of hyperlipidemia could lead to regression of atherosclerotic nodules and impressive clinical improvement in certain patients.

Arteriosclerosis↗

PubMed1975

Clinical, haemodynamic, and coronary angiographic correlates of angina pectoris in patients with severe aortic valve disease.

Of 88 consecutive patients aged 20 to 77 years with severe symptomatic aortic valve disease requiring surgery, 51 patients had angina pectoris; of these 51, 41 had predominant aortic stenosis and 10 had severe aortic regurgitation. All patients with angina pectoris underwent coronary angiography; significant coronary arterial disease was encounted in 24 per cent of those with aortic stenosis and 20 per cent of those with aortic regurgitation. By contrast, of 37 patients without angina pectoris 19 underwent coronary arteriography; none showed significant coronary artery disease (P smaller than 0.05). Among patients with angina pectoris, 17 per cent of those with aortic stenosis experienced prolonged, rest or nocturnal pain, compared to 70 per cent of those with aortic regurgitation (P smaller than 0.005). At the time of onset of angina pectoris, there were features of heart failure in 34 per cent of those with aortic stenosis, and in 90 per cent of those with aortic regurgitation (P smaller than 0.005). Nitroglycerin promptly relieved angina pectoris in 56 percent of patients with aortic stenosis and in 50 per cent of those with aortic regurgitation (P smaller than 0.05). Neither the pattern of angina pectoris nor the response to nitroglycerin was dependent upon the coexistence of significant coronary artery disease. In patients with aortic stenosis, there was not significant difference between those with angina pectoris, and those without angina with regard to left ventricular end-diastolic volume, end-diastolic pressure, ejection fraction, peak systolic pressure, wall thickness, cardiac index, or the product of these factors. In patients with aortic regurgitation, cardiac index was significantly lower (P smaller than 0.05), left ventricular end-diastolic volume tended to be larger, and ejection fraction tended to be lower in patients with angina pectoris as opposed to those without angina pectoris.

Adult↗

PubMed1975

Postinfarction ventricular septal defect with posterior ventricular aneurysm. Result of a single distal right coronary artery obstruction.

A patient with postinfarction ventricular septal defect, posterior aneurysm, severe congestive heart failure, and significant atherosclerosis in the distal right coronary artery only is reported. Closure of the defect resulted in quich recovery of the patient. We demonstrated that a single significant lesion in one coronary artery can cause rupture of the interventricular septum.

Coronary Angiography↗

PubMed1975