Biomedical subjects

C T Thompson

Publications and source records attributed to C T Thompson.

13 recordsLinked to original sources

PubMed1995

Selective use of computed tomography and diagnostic peritoneal lavage in blunt abdominal trauma.

The purpose of this study was to attempt to identify those blunt trauma patients in whom expensive diagnostic studies such as computed tomography and diagnostic peritoneal lavage are unnecessary to exclude intra-abdominal injury. The medical records of 1096 blunt trauma patients evaluated at an urban level I trauma center were reviewed. Because of the urgent need to exclude intra-abdominal hemorrhage in patients with hypotension (blood pressure < 90 mm Hg), and the difficulty in obtaining reliable information from abdominal examination in patients with Glasgow Coma Scale scores < 11 or spinal cord injury, 140 patients meeting these criteria were reviewed but excluded from statistical analysis. Six groups of major associated injuries felt to be potential risk factors for the prediction of intra-abdominal injury were analyzed in the 956 remaining patients. Only two of these potential risk factors, namely chest injury (p = 0.0001) and gross hematuria (p = 0.0003) attained statistical significance. All of the 44 significant intra-abdominal injuries occurred in the group of 253 patients that had either an abnormal abdominal examination, one of the statistically significant risk factors, or both, for a sensitivity of 100%. Of the 703 patients with a normal abdominal examination and no risk factors, none had a significant abdominal injury, for a negative predictive value of 100%. This study suggests that patients with either an abnormal abdominal examination or one of the two statistically derived risk factors require adjunctive diagnostic evaluation with diagnostic peritoneal lavage or computed tomography scan to exclude intra-abdominal injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗

PubMed1994

Comparative genomic hybridization in the detection of DNA copy number abnormalities in uveal melanoma.

Genomic instability appears to play an important role in the development, growth, invasiveness, and eventual metastasis of the neoplastic cell. We have used a powerful new technique, comparative genomic hybridization, to evaluate genetic alterations in 10 fresh frozen uveal melanomas. Comparative genomic hybridization utilizes dual fluorescence in situ hybridization to characterize chromosome deletions and duplications, allowing for simultaneous evaluation of the entire human genome. Several consistent chromosomal abnormalities were detected. This study confirmed previous findings obtained using standard cytogenetic techniques but demonstrated an increased incidence in abnormalities of chromosomes 3 and 8; there was loss of chromosome 3 and duplication of 8q. In addition, we identified, although less frequently, other recurrent abnormal regions including alterations on chromosomes 6p, 7q, 9p, and 13q.

Chromosome Aberrations↗

PubMed1993

Cytogenetic profiling using fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH).

Fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) allow cytogenetic analyses of primary tumors without culture. CGH allows detection and mapping of allelic imbalance by simultaneous in situ hybridization of differentially labeled tumor (green fluorescing) and normal DNA (red fluorescing) to a normal human metaphase spread. Regions of increased or decreased copy number in the tumor are mapped onto the normal metaphase chromosomes as increases or decreases in the green to red fluorescence ratio. This technique gives a comprehensive assessment of gene dosage imbalance throughout the tumor. However, it is limited, at present, to fairly large tumors containing few normal cells. FISH, on the other hand, allows analysis of DNA sequence copy number at specific loci in single nuclei. A wide variety of DNA probes is available for FISH, including chromosome-specific probes which hybridize to alpha-satellite pericentromeric DNA regions (to detect changes in specific chromosome copy number and overall ploidy) and specific locus probes targeting 20-150 kilobase sequences (to detect specific amplifications, deletions, breakpoints, or rearrangements). FISH using these probes has been applied to interphase nuclei in touch preparations, smears from fine needle aspirates, and thin (< 6 microns) and thick (> 20 microns) sections cut from formalin-fixed, paraffin-embedded tissue. Analysis of thick sections allows accurate actual signal enumeration within the histological context. This approach may allow analysis of subtle premalignant, early malignant, and infiltrating tumors in which malignant cells must be differentiated from nonmalignant cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome Aberrations↗

PubMed1992

Community hospital level II trauma center outcome.

Currently, level II trauma center standards allow trauma surgeons to take call out-of-hospital. To address the concern that this practice may adversely influence outcome, we tested the hypothesis that the survival of injury victims treated at a level II trauma center is significantly different from that predicted by the Major Trauma Outcome Study (MTOS). In addition, we examined the impact of trauma surgeons taking call out-of-hospital on the survival of patients with severe thoracoabdominal injury. Over a 26-month period, a total of 3,689 consecutive injured patients who were treated at a community hospital level II trauma center were entered into this study. There was no significant difference between the MTOS survival and the actual survival in the overall population (96% vs. 97%, respectively; Z statistic = ns). Among the patients with severe thoracoabdominal injury (i.e., Abbreviated Injury Scale score greater than or equal to 3), there was no significant difference in survival between the patients whose arrival time corresponded to the presence of an in-hospital surgeon (0700-1800 hours) versus those who arrived when a surgeon was generally out-of-hospital (1801-0659 hours), (76% vs. 81%, respectively; p = ns). From these data we conclude that there was no significant difference between the survival observed and that predicted by the MTOS at our community hospital, which complies with level II trauma center standards. Furthermore, in the cohort with severe thoracoabdominal injury, the response of trauma surgeons from out-of-hospital did not adversely influence survival.

Emergency Medical Service Communication Systems↗

PubMed1989

Quantitation of total DNA per cell in an exponentially growing population using the diphenylamine reaction and flow cytometry.

The diphenylamine assay used to estimate the absolute mass of DNA/cell as well as absolute differences in DNA content between cell populations is based upon the assumption that all of the cells are in the G0 or G1 phase of the DNA synthetic cycle. However, if cells are in exponential growth and synthesizing DNA, portions of the population will be in S or G2 phases and the diphenylamine assay will overestimate the total mass of DNA/cell. Conversely, flow cytometry (FCM) can estimate relative differences in total DNA/cell and the proportions of an exponentially growing population in G1, S, and G2 but cannot estimate absolute mass or differences in DNA/cell. In this report, we describe a methodology of combined diphenylamine and FCM assays of total DNA/cell which is applicable to any eukaryotic cell population. The method involves using the two assay methods concurrently and correcting the diphenylamine data for the FCM-derived distribution of the cells within the DNA synthetic cycle. The methodology was tested on single-cell-derived stocks of the obligate intracellular protozoan parasite Trypanosoma cruzi which displays marked but stable intraspecific heterogeneity.

Animals↗

PubMed1985