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Biomedical subjects

K Gates

Publications and source records attributed to K Gates.

At least 19 recordsLinked to original sources
PubMed2001

Prediction of the extent and severity of left ventricular dysfunction in anterior acute myocardial infarction by the admission electrocardiogram.

BACKGROUND: The grade of ischemia, as detected by the relation between the QRS complex and ST segment on the admission electrocardiogram, is associated with larger infarct size and increased mortality rates in acute myocardial infarction. METHODS: We assessed the correlation between left ventricular function and the admission electrocardiogram in 151 patients with first anterior acute myocardial infarction who received thrombolytic therapy and underwent cardiac catheterization at 90 minutes and before hospital discharge. The number of leads with ST elevation, sum of ST elevation, maximal Selvester score, and the presence of severe (grade 3) ischemia were determined in each electrocardiogram. Left ventricular ejection fraction, the number of chords with wall motion abnormalities, and the severity of dysfunction (SD/chord) were determined. RESULTS: At 90 minutes, the 39 ischemia grade 3 patients had lower ejection fraction than the 112 grade 2 patients. Both at 90 minutes and at hospital discharge, the grade 3 group had more chords with wall motion abnormalities and more severe regional dysfunction (SD/chord). However, the number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had no correlation with ejection fraction at 90 minutes and only mild correlation with the extent of dysfunction (number of chords) at 90 minutes. There was no correlation between either the number of leads with ST elevation or the sum of ST elevation and the severity of regional dysfunction. CONCLUSIONS: The number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had only mild correlation with the extent of myocardial dysfunction but not with the severity of dysfunction. Grade 3 ischemia is predictive of more extensive myocardial involvement and greater severity of regional dysfunction.

Aged↗
PubMed2001

Adhesive tape analysis: establishing the evidential value of specific techniques.

This study investigated the evidential value of specific methods of analysis for packaging tapes and clear adhesive tapes available in Australia. Fifty-eight adhesive tapes were analyzed using a wide range of optical, physical, and chemical techniques. The results were collated for the purpose of creating an Australian database of adhesive tapes, which would be of assistance in criminal investigation. Each technique was evaluated for its discriminating power, both for comparative purposes and for the identification of adhesive tapes by comparing unknown samples with the database. The combined discriminating power of the techniques applied is very high. It is possible to individually identify the source of an unknown adhesive tape sample in many instances by searching the database. It is also possible to form an opinion on the significance of a failure-to-discriminate result in comparative casework. Further work is still needed to expand and update the database, as well as compiling data on the relative market share of various products.

Journal Article↗
PubMed2000

Use of resources, quality of life, and clinical outcomes in patients with and without new Q waves after thrombolytic therapy for acute myocardial infarction (from the GUSTO-I trial).

Previous reports indicate that patients who do not develop Q waves after thrombolytic therapy are a different population with a better long-term survival than those who do develop Q waves. However, the use of resources, quality of life, and health status of this population have not been fully evaluated. Using data from the Economics and Quality of Life subset of the Global Utilization of Streptokinase and tPA for Occluded Arteries study, we examined 30-day and 1-year mortality, use of resources, and quality-of-life measures among 1,830 of 3,000 patients with acute myocardial infarction and ST-segment elevation treated with thrombolytic therapy. At hospital discharge, 555 patients (30.2%) had not developed Q waves. These patients had lower mortality than patients with Q waves at 30 days (1.6% vs 4.5%, p <0.01) and at 1 year (4.7% vs 6.8%, p <0.04). Recurrent chest pain and dyspnea were similar at 30 days and 1 year. Patients without Q waves had significantly more angiography and trends toward higher readmission, revascularization, and use of calcium antagonists at 30 days. Angiography, revascularization, readmission, and quality of life were equivalent from 30 days to 1 year, with no sign of late instability. Logistic regression analysis showed an association between in-hospital revascularization and better survival and quality of life at 1 year. Conversely, there was no association between in-hospital use of calcium antagonists and outcome to explain the lower mortality in non-Q-wave patients. The absence of Q waves after thrombolytic therapy is a marker of success, implying better prognosis and equivalent quality of life, use of resources, and health status than for patients with Q-wave acute myocardial infarction and no sign of long-term unstable clinical course.

Aged↗
PubMed1999

Terminal QRS distortion on admission is better than ST-segment measurements in predicting final infarct size and assessing the Potential effect of thrombolytic therapy in anterior wall acute myocardial infarction.

We assessed predicting final infarct size (using predischarge Selvester score) by 3 electrocardiographic variables in 267 patients with first anterior wall acute myocardial infarction (AMI) undergoing (n = 86) or not undergoing (n = 181) thrombolysis. Patients with previous AMI or inverted T waves in leads with ST elevation were excluded. The sum (sigma) of ST elevation, the number of leads with ST elevation, and the initial electrocardiographic pattern were determined on the admission electrocardiogram (absence (QRS-) or presence (QRS+) of distortion of the terminal portion of the QRS in > or =2 leads (J point > or =0.5 of the R-wave amplitude in leads I, aVL, V4 to V6, or presence of ST elevation without S waves in leads V1 to V3). There was no association between sigmaST elevation and final infarct size in patients who did or did not receive thrombolytic therapy. Analysis of covariance showed that the number of leads with ST elevation (F = 19.6), thrombolysis (F = 25.2), and QRS+ initial pattern (F = 19.5) were all associated with final infarct size (p <0.0001 for all). Among patients who did not receive thrombolytic therapy, the average Selvester score was 19.7+/-9.9 for the QRS- patients and 26.1+/-10.4 for the QRS+ patients (p = 0.02). Among patients who received thrombolytic therapy, the average Selvester score was 11.7+/-9.8 for the QRS- patients and 24.2+/-10.1 for the QRS+ patients (p <0.0001). Thrombolysis reduced final Selvester score only in the QRS- group (p <0.00001), but not in the QRS+ group (p = 0.45). It is concluded that (1) final Selvester score in anterior wall AMI can be predicted by the number of leads with ST elevation, the initial electrocardiographic pattern, and thrombolysis, and (2) thrombolysis reduces final Selvester score only in patients with QRS- pattern.

Adult↗
PubMed1999

Correlation of angiographic findings and right (V1 to V3) versus left (V4 to V6) precordial ST-segment depression in inferior wall acute myocardial infarction.

This study assessed whether differences in the underlying mechanisms for various patterns of precordial ST-segment depression with inferior acute myocardial infarction (AMI) are associated with poorer prognoses. We studied 1,155 patients with inferior AMI who underwent thrombolysis in the Global Utilization of Streptokinase and TPA for Occluded arteries (GUSTO-I) angiographic substudy: those without precordial ST depression (n = 412; 35.7%), those with maximum ST depression in leads V1 to V3 (n = 547; 47.4%), and those with maximum ST depression in leads V4 to V6 (n = 196; 17.0%) on admission electrocardiogram. We compared the infarct-related artery, presence of left anterior descending or multivessel coronary artery disease, and left ventricular function among groups. Patients with maximum ST depression in leads V4 to V6 more often had 3-vessel disease (26.0%) than those without precordial ST depression (13.5%) or those with ST depression in leads V1 to V3 (15.7%; p = 0.002), and they had a lower ejection fraction (median 54% vs 60% and 55%, respectively; p <0.001). Patients with maximum ST depression in leads V1 to V3 less often had AMIs due to proximal right coronary artery obstruction (23.9%) than patients without precordial ST depression (35.2%) or those with ST depression in leads V4 to V6 (40.0%; p = 0.001) and had larger AMIs as estimated by peak creatine kinase. Different patterns of precordial ST depression are associated with distinctive coronary anatomy. ST depression in leads V4 to V6, but not V1 to V3, confers a greater likelihood of multivessel coronary artery disease.

Acute Disease↗
PubMed1997

Thrombolysis and Q wave versus non-Q wave first acute myocardial infarction: a GUSTO-I substudy. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries Investigators.

OBJECTIVES: We assessed the outcomes of patients with a first myocardial infarction with ST segment elevation, with and without the development of abnormal Q waves after thrombolysis. BACKGROUND: Prethrombolytic era studies report conflicting short-versus long-term mortality in the overall non-Q wave population, probably related to its heterogeneity. METHODS: Patients with no electrocardiographic (ECG) confounding factors or evidence of previous infarction were included. Q wave infarction was defined as a Q wave duration > or = 30 ms in lead aVF; R wave > or = 40 ms in lead V1; any Q wave or R wave < or = 10 ms and < or = 0.1 mV in lead V2; or Q wave > or = 40 ms in at least two of the following leads: I, aVL, V4, V5 or V6. In-hospital clinical events and mortality at 30 days and 1 year were assessed. RESULTS: No Q waves developed in 4,601 (21.3%) of the 21,570 patients. This group comprised more women and had a lower Killip class, lower weight and less anterior baseline ST elevation. The non-Q wave group had less in-hospital cardiogenic shock (2.1% vs. 3.3%, p < 0.0001), less heart failure (8.5% vs. 13.9%, p < 0.0001) and a trend toward less stroke (0.7% vs. 1.0%, p = 0.07) but an increased use of angioplasty (28% vs. 24%, p = 0.0001). The unadjusted mortality rate in the non-Q wave group was lower at 30 days (0.9% vs. 1.8%, p = 0.0001) and 1 year (2.7% vs. 4.2%, p = 0.0001), as was the adjusted 30-day mortality rate (4.8% vs. 5.3%, p < 0.0001). CONCLUSIONS: Patients with no ECG confounding factors or evidence of previous infarction who do not develop Q waves after thrombolysis have a better 30-day and 1-year prognosis than patients with a Q wave infarction.

Aged↗
PubMed1996

Cloning, chromosomal localization, physical mapping, and genomic characterization of HKR3.

The Krüppel-type zinc finger proteins are members of a conserved family of transcription factors that are important in developmental regulation. Altered expression of several of these proteins has been implicated in human diseases, including cancer. We report the cloning, mapping, and characterization of the zinc finger gene Human Krüppel-Related 3 (HKR3). Genomic clones of HKR3 were isolated from a P1 library and localized to human chromosome subband 1p36.3 by human-rodent somatic cell hybrid mapping and fluorescence in situ hybridization. The gene was physically mapped to within 40 kb of D1S214 by YAC content and long-range restriction mapping. HKR3 spans 9.5 kb of genomic DNA and is contained in 11 exons. Sequencing defined each of the exon/intron splice site junctions and identified a CpG island in the 5' region of the gene. HKR3 is ubiquitously expressed in human tissues as at least two major transcripts, the shorter of which excludes a conserved finger-associated box and a putative acidic activation domain contained in the full-length transcript. HKR3 is a novel zinc finger gene that maps to a region of the genome commonly rearranged or deleted in human cancers.

Adult↗
PubMed1995

Analysis of high-resolution ECG changes during percutaneous transluminal coronary angioplasty.

The authors have hypothesized that low-level, electrocardiographic changes may accompany transient ischemia induced by percutaneous transluminal coronary angioplasty. Altered repolarization may manifest as subclinical changes in ST-T morphology. Changes in depolarization may manifest as low-amplitude notches and slurs, a phenomenon the authors term abnormal intra-QRS potentials. The initial aim of this study was to characterize changes in high-resolution electrocardiograph signals that might be linked to ischemic involvement of the ventricular myocardium.

Angioplasty, Balloon, Coronary↗
PubMed1994

Retrospective evaluation of flow cytometry as a platelet crossmatching procedure.

We performed a retrospective analysis of flow cytometry as a platelet crossmatching procedure. Sera from 17 alloimmunized refractory patients were tested against 32 donor platelets, which had been stored as platelet-rich plasma for up to 36 months. Overall, 14/32 (44%) crossmatches were positive. The mean 1 h posttransfusion corrected count increments (CCIs) were 9,195 and 2,269 for a negative and a positive crossmatch, respectively. The predictive value of a positive crossmatch was 86%, whereas the predictive value of a negative crossmatch was 56%. When samples with low background fluorescence or with high panel-reactive antibody (PRA) levels were evaluated separately, the accuracy of the crossmatch improved from 69% to 80%. When compared to the platelet adhesion immunofluorescence test (PAIFT) and the standard and antiglobulin-enhanced lymphocytotoxicity tests for the detection of HLA antibodies, flow cytometry appeared to be more sensitive. We conclude that flow cytometry is a useful technique for platelet crossmatching, particularly for alloimmunized patients for whom HLA compatible platelets may not be readily available.

Blood Grouping and Crossmatching↗
PubMed1994

A comprehensive study of physical parameters, biomechanical properties, and statistical correlations of iliac crest bone wedges used in spinal fusion surgery. II. Mechanical properties and correlation with physical parameters.

Iliac crest wedges have been the most frequently used bone graft in spinal fusion procedures since the 1970s. Physical parameters and correlations among physical parameters of allogeneic iliac crest wedges have been described in part I of this series. This article discusses the mechanical properties, as well as their correlations with physical parameters, of iliac crest wedges. A total of 250 frozen-thawed, freeze-dried, and rehydrated iliac crest wedges were used in this study. The axial load-bearing capacities for wedges in the three subgroups showed no statistically significant differences, however, rehydrated wedges appeared to have the greatest load bearing capacity and compressive strength. In addition, rehydrated wedges were more deformable than either the frozen-thawed or freeze-dried wedges. Based on biomechanical properties, it is suggested that rehydrated (1 hour in vacuo), or frozen-thawed iliac crest wedge should be used in spinal fusion procedures, and the direct clinical application of nonrehydrated freeze-dried wedges should be avoided.

Aging↗
PubMed1994

A comprehensive study of physical parameters, biomechanical properties, and statistical correlations of iliac crest bone wedges used in spinal fusion surgery. IV. Effect of gamma irradiation on mechanical and material properties.

The effects of gamma irradiation on mechanical and material properties of iliac crest wedges used in spinal fusion surgery were studied using uniaxial compression testing. The irradiated iliac crest wedges were exposed to 2-2.5 mrad as fresh-frozen and freeze-dried tissues. There were no significant differences in mechanical or material properties of the iliac crest wedges exposed to dosages of 2-2.5 mrad when compared to the nonirradiated wedges. It is suggested that 2-2.5 mrad is an acceptable dose for gamma irradiation sterilization of iliac crest wedges used in spinal fusion surgery and that these tissues may be treated at either the preprocessing or postprocessing stage of wedge production.

Adult↗
PubMed1994

ECG myocardial infarct size: a gender-, age-, race-insensitive 12-segment multiple regression model. I: Retrospective learning set of 100 pathoanatomic infarcts and 229 normal control subjects.

In this early study of ongoing work with multiple regression modeling for mapping myocardial infarct (MI) into 12 left ventricular (LV) segments, promising results have been presented using electrocardiographic (ECG) QRS variables that are gender, age, and race insensitive (GARI), the GARI-QRS 12-segment multiple regression model. These include Q, R, and S duration, expressed as percentage total QRS duration, and R/Q duration, R/Q amplitude, R/S duration, and R/S amplitude variables. For version I, building 12 regression models using 68 single and 32 multiple MIs, the GARI-QRS variables correlated with pathoanatomic MI in each of 12 segments with r values ranging from .67 to .88. In version II of the model, using all MIs and 229 normal subjects, r = .73-.91. Version II predictions of MI in 12 LV segments for each subject were used to calculate the predicted total percentage LV infarct, which correlated well with that found at autopsy. The r values found were .81 for all single MIs, .73 for multiple MIs, and .80 for all MIs taken together. With refinements of the input ECG variables to include (1) improvement in the GARI-QRS variables, (2) adding a significant number of subjects with hypertrophies and conduction defects with and without MI to an expanded learning set, and (3) applying the enhanced 12-LV-segment regression models to a similar test set, it is to be expected that these regression models can be improved even further in such a way as to be applicable to general clinical populations using routine computerized ECG analysis programs.

Adult↗
PubMed1980

Molds in brined cucumbers: cause of softening during air-purging of fermentations.

Softening of cucumbers in fermentations purged at high air-flow rates was caused by molds growing in the brined cucumbers, not in the brine. This conclusion is based on the following results: (i) no microorganisms were isolated in significant numbers from brines that caused softening of pasteurized brined cucumbers, (ii) no pectinolytic enzyme activities were produced in cucumber brines in the absence of cucumbers, (iii) the pickles in some air-purged fermentations became very soft without the appearance of any pectinolytic enzyme activity in the brine, (iv) mold hyphae were consistently observed in tissues of soft pickles, (v) molds consistently developed in cultures of slices of surface sterilized cucumbers taken from fermentations in which soft pickles were subsequently found, and (vi) molds belonging to the genera Alternaria, Fusarium, and Mucor isolated from slices all softened pasteurized brined cucumbers.

Journal Article↗