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Biomedical subjects

B Thompson

Publications and source records attributed to B Thompson.

At least 145 records · Page 8Linked to original sources
PubMed1988

MR imaging of head trauma: review of the distribution and radiopathologic features of traumatic lesions.

The distribution and extent of traumatic lesions were prospectively evaluated with MR imaging in 40 patients with closed head injuries. Primary intraaxial lesions were classified according to their distinctive topographical distribution within the brain and were of four main types: (1) diffuse axonal injury (48.2%), (2) cortical contusion (43.7%), (3) subcortical gray-matter injury (4.5%), and (4) primary brainstem injury (3.6%). Diffuse axonal injury most commonly involved the white matter of the frontal and temporal lobes, the body and splenium of the corpus callosum, and the corona radiata. Cortical contusions most frequently involved the inferior, lateral, and anterior aspects of the frontal and temporal lobes. Primary brainstem lesions were most commonly seen in the dorsolateral aspects of the rostral brainstem. The pattern and distribution of primary lesions seen by MR were compared with those expected from previous pathologic studies and found to be quite similar. Our data and review of the literature would also indicate that MR detects a more complete spectrum of traumatic lesions than does CT. Secondary forms of injury (territorial arterial infarction, pressure necrosis from increased intracranial pressure, cerebral herniation, secondary brainstem injury) were also visible by MR in some cases. The level of consciousness was most impaired in patients with primary brainstem injury, followed by those with widespread diffuse axonal injury and subcortical gray-matter injury. The best MR imaging planes, pulse sequences, and imaging strategies for evaluating and classifying traumatic lesions were evaluated, and the mechanisms by which traumatic stresses result in injury were reviewed. MR was found to be superior to CT and to be very effective in the detection of traumatic head lesions and some secondary forms of injury. While T2-weighted images were most useful for lesion detection, T1-weighted images proved to be most useful for anatomic localization and classification.

Adolescent↗
PubMed1988

Prospective comparative study of intermediate-field MR and CT in the evaluation of closed head trauma.

Forty patients with closed head trauma were evaluated prospectively with CT and intermediate-field-strength MR imaging to compare the diagnostic efficacies of the two techniques. Traumatic lesions were detected in 38 patients. The severity of injury, as determined by the Glascow Coma Scale, ranged from 3 to 14. The sensitivities of CT and MR were calculated for all subgroups of lesions: (1) hemorrhagic and nonhemorrhagic intraaxial lesions (diffuse axonal injury, cortical contusion, subcortical gray-matter injury, primary brainstem injury); (2) extraaxial hematomas (subdural, epidural); and (3) diffuse hemorrhage (subarachnoid, intraventricular). CT and MR (T1- and T2-weighted) studies were both highly and comparably sensitive in the detection of hemorrhagic intraaxial lesions. MR scans, however, were much more sensitive in detecting nonhemorrhagic lesions. cortical contusions and diffuse axonal injury constituted 91.9% of all intraaxial lesions. The sensitivities of the imaging techniques for this combined group of lesions were (1) nonhemorrhagic lesions (CT = 17.7%, T1-weighted MR = 67.6%, T2-weighted MR = 93.3%); (2) hemorrhagic lesions (CT = 89.8%, T1-weighted MR = 87.1%, T2-weighted MR = 92.5%). MR was also significantly better in detecting brainstem lesions (CT = 9.1%, T1-weighted MR = 81.8%, T2-weighted MR = 72.7%). The sensitivities of the diagnostic studies in the detection of extraaxial hematomas were CT = 73.2%, T1-weighted MR = 97.6%, T2-weighted MR = 90.5%). Intraventricular hemorrhage was consistently seen with all three imaging studies, but subarachnoid hemorrhage was detected much more frequently with CT. In summary, MR has clear advantages over CT in evaluating closed head trauma. Although its sensitivity in detecting hemorrhagic lesions is similar to that of CT, it is much better than CT in detecting nonhemorrhagic lesions, which are more prevalent. MR is more useful than CT in classifying primary and secondary forms of injury and directing treatment. CT's one advantage over MR is its ability to more rapidly assess unstable patients who may need surgery.

Adolescent↗
PubMed1988

Binding studies of three water-soluble polycationic porphyrins with human serum albumin.

The binding stoichiometry and equilibria of three polycationic water-soluble porphyrins with human serum albumin (HSA) have been determined by fluorescence quenching and filtration methods in 0.1M phosphate buffer, pH 7.2 at 25 degrees. For one porphyrin the binding equilibrium was also measured by measuring the lifetime of tryptophan and also by measuring the polarization of bound porphyrin. Energy transfer between the porphyrin and the tryptophan residue of HSA has been studied.

Humans↗
PubMed1987

Dietary fat in experimental nephrotic syndrome: beneficial effects of fish oil on serum lipids and, indirectly, on the kidney.

Three isocaloric diets with different fat composition were fed to rats for seven weeks after the production of nephrotic syndrome by adriamycin. The effects of feeding 3% and 14% fish oil were compared with those of feeding beef fat. At the fourth week of feeding the levels of triglycerides and cholesterol were lower in both fish oil fed groups. At the seventh week these levels, and the LDL cholesterol, were lower only in the 14% fish oil group. In rats fed beef fat, but not in those fed fish oil, there was a striking positive correlation of the four-week serum triglycerides and cholesterol with the seven-week serum creatinine level and with the degree of glomerular hyalinosis and endothelial swelling. The favorable effects of fish oil feeding on serum lipids may have a protective effect on the development of glomerular damage.

Animals↗
PubMed1987

Successful resuscitation using transcutaneous cardiac pacing.

Reported here is the case of a patient suffering from hemodynamically significant bradycardia in which the use of transcutaneous cardiac pacing resulted in successful resuscitation, obviating the need for invasive pacing. During pacing, intra-arterial recordings of blood pressure demonstrated higher pulse pressures for paced beats than for the patient's own escape beats. Recent data regarding the use of non-invasive transcutaneous cardiac pacing is also reviewed.

Aged↗
PubMed1987

Does the use of oral contraception depress DZ twinning rates?

Data based on total births from a geographically defined population with zygosity determined from blood samples and placentation and with data on the use of oral contraceptives routinely collected in early pregnancy showed no association between oral contraceptive use prior to pregnancy in either MZ or DZ twinning. Three mutually exclusive control groups of singletons were used to take account of age, parity and secular trends.

Birth Rate↗
PubMed1987

Receptor-mediated inositol phosphate formation in relation to calcium mobilization: a comparison of two cell lines.

Previous studies indicated that activation of alpha 1-adrenergic receptors in BC3H-1 muscle cells (S. K. Ambler and P. Taylor, J. Biol. Chem. 261:5866-5871, 1986) and muscarinic receptors in 1321N1 astrocytoma cells (S. B. Masters, T. K. Harden, and J. H. Brown, Mol. Pharmacol. 27:325-332, 1985) resulted in the rapid mobilization of Ca2+ from internal stores of both cell types. Paradoxically, alpha 1-adrenergic agonists did not rapidly increase inositol trisphosphate (Ins-P3) formation in BC3H-1 cells, in distinction to the rapid increase in Ins-P3 accumulation observed in 1321N1 cells after muscarinic stimulation. To determine whether the variations observed in the Ins-P3 response could be ascribed to differences in the relative amounts of inositol 1,4,5-trisphosphate, inositol 1,3,4-trisphosphate, and inositol tetrakisphosphate (respectively, Ins-1,4,5-P3, Ins-1,3,4-P3, and Ins-P4), we have separated the individual inositol phosphates by high-performance liquid chromatography and examined the rates of conversion of individual inositol phosphates in the two types of cells. Muscarinic stimulation of 1321N1 cells resulted in increased Ins-1,4,5-P3 production, as well as the rapid production of Ins-1,3,4-P3 and Ins-P4. Application of alpha 1-agonist to BC3H-1 cells produced a modest but delayed increase in accumulation of Ins-1,4,5-P3. Adrenergic stimulation also resulted in a smaller and even slower production of Ins-1,3,4-P3, and Ins-P4 could not be detected in BC3H-1 cells under any conditions employed. Thus, over a 30-sec interval in which Ca2+ is mobilized to a maximum extent, increases in Ins-1,4,5-P3, Ins-1,3,4-P3, or Ins-P4 amounted to less than 10% over basal values in BC3H-1 cells. These results indicate that the regulation of Ins-P3 isomer formation and conversion may vary substantially between different cell types. In addition, if inositol 1,4,5-trisphosphate is the sole mediator of intracellular Ca2+ release, it is necessary to propose that an increase in Ins-1,4,5-P3 sufficient to mobilize Ca2+ rapidly may occur only within discrete cellular localities in some cell types. According, it may not be possible to detect the increases in Ins-1,4,5-P3 over basal concentrations when measuring total cellular inositol phosphates.

Animals↗
PubMed1987

Small cell carcinoma of the lung: influence of age on treatment outcome.

Two hundred twenty-three patients between 29 and 78 years of age with small cell cancer of the lung were studied in serial protocols at the University of Maryland Cancer Center from 1975 to 1982. Each of these patients received chemotherapy consisting of doxorubicin, cyclophosphamide, and etoposide. In this paper we explore age and its interaction with the patient's extent of disease as it relates to clinical outcome variables such as the achievement of a complete response (CR), survival times, and various measures of toxicity. Preliminary evidence is found to suggest that an age-extent of disease interaction affects both the probability of obtaining a CR and the length of survival. Patients of all ages can benefit from treatment of small cell carcinoma of the lung, with CR as the treatment goal. However, increased toxicity and early death remain as barriers to successful treatment of the elderly.

Actuarial Analysis↗
PubMed1986

Efficacy of single-agent therapy with azlocillin, ticarcillin, and amikacin and beta-lactam/amikacin combinations for treatment of Pseudomonas aeruginosa bacteremia in granulocytopenic rats.

The efficacy of azlocillin, ticarcillin, and amikacin as single agents and the penicillin/amikacin combinations for treatment of Pseudomonas aeruginosa bacteremia during cyclophosphamide-induced severe neutropenia in a rat model were assessed. Equivalent antibiotic dosing was based on the time rat serum antibiotic levels were above the minimal bactericidal concentration for the challenge organism. Antibiotic therapy was administered for 62 hours after bacterial challenge. Antimicrobial efficacy was based on the rate of bacteremia, the emergence of resistant organisms during therapy, life-table survival analysis, and rat survival seventy-two hours after bacterial challenge. For infection with a P. aeruginosa strain susceptible to all study antibiotics, therapy with azlocillin and ticarcillin (given so as to be equipotent) were equivalent, as judged by bacteremia rates or rat survival. However, combination therapy prevented the emergence of organisms resistant to azlocillin, but not to ticarcillin. Amikacin-containing combinations were more effective than single-agent regimens.

Agranulocytosis↗
PubMed1986

A new evaluation method for instructors of advanced cardiac life support.

This study evaluated the ability of a specific educational program to teach instructors of advanced cardiac life support (ACLS) how to identify errors committed by team leaders of cardiac arrest simulations. The design compared experimental and control groups for differences in identification of critical performance errors, grade assignments and errors specifically emphasized in the educational program. The group receiving the educational program documented more critical performance errors (1.70 vs. 1.10, P = 0.006), made more correct grade assignments (2.35 vs. 2.0, P = 0.026), and identified more errors that were emphasized in the educational program (3.61 vs. 2.25, P = 0.0001) than the control group. The data strongly suggests that the educational program accounted for the observed differences.

Educational Measurement↗
PubMed1986

Bystander/first responder CPR: ten years experience in a paramedic system.

The effectiveness of bystander CPR recently has been challenged. We undertook a ten-year retrospective review of our prehospital experience with witnessed cardiorespiratory arrest to ascertain save rates in patients receiving and not receiving CPR before paramedic advanced life support (ALS). Traumatic and poisoning arrests and children less than 18 years old were excluded. A total of 1,905 patients presenting to a paramedic system from November 1, 1973, to October 31, 1983, were bystander-witnessed arrests and attempted paramedic resuscitations. Four hundred five paramedic-witnessed arrests were excluded. One hundred eighty-two of 1,248 (14.6%) who had CPR initiated before paramedic ALS arrival were saves, compared to 38 of 252 (15%) who had no CPR initiated until paramedic arrival (P = NS). A save was defined as a patient discharged from the hospital. The respective save rates for coarse ventricular fibrillation were 148 of 628 (23.6%) (CPR before paramedic arrival) vs 35 of 151 (CPR delayed until paramedic arrival) (23.2%); electromechanical dissociation (EMD), 11 of 209 (5.3%) vs 0 of 38; asystole, 19 of 401 (4.7%) vs 3 of 61 (4.9%); and ventricular tachycardia, four of ten (40%) vs 0 of two. In this prehospital system, bystander/first responder CPR was found not to improve hospital discharge rates except in patients with initially documented rhythm of EMD.

Adult↗