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Biomedical subjects

E Abraham

Publications and source records attributed to E Abraham.

At least 145 records · Page 8Linked to original sources
PubMed1990

Haemorrhage produces depressions in alloantigen-specific immune responses in the mouse through activation of suppressor T cells.

The development of cell-mediated and humoral immune responses in BALB/c mice (H-2d) directed toward El4 cells (H-2b) was suppressed (cell-mediated cytotoxicity, 40-50% of control; antibody titres 127 +/- 17 versus 287 +/- 17 in controls) following haemorrhage of 30% total blood volume. This haemorrhage-induced depression of immune response can be transferred to normal recipients with T cells (3 x 10(7] from haemorrhaged syngeneic donors. Flow microfluorimetry (FMF) analysis showed no shift in CD8:CD4 ratios following haemorrhage. These results suggest that haemorrhage suppresses immune response through activation of suppressor T cells.

Animals↗
PubMed1990

Cardiorespiratory effects of pressure controlled ventilation in severe respiratory failure.

Cardiorespiratory values were measured in ten patients with severe respiratory failure on volume controlled and pressure controlled ventilation. Tidal volume, respirator rate, PEEP, auto-PEEP, inspiratory:expiratory ratio (1:2) and FIo2 were maintained at the same value for both ventilatory modalities. Changing from VCV to PCV was associated with significant improvements in PaO2, oxygen delivery, and tissue oxygen consumption. Peak inspiratory pressure fell. There were no significant changes in other cardiorespiratory values, such as arterial blood pressure, nor in ventilatory measurements, such as mean airway pressure, associated with the use of PCV. These results suggest that PCV may be a beneficial ventilatory modality in the treatment of severe respiratory failure since it results in improvement in arterial oxygenation, tissue oxygen delivery and utilization without any concomitant adverse effects on other hemodynamic or ventilatory factors.

Adult↗
PubMed1990

Medical malpractice claims in cardiology.

Diagnostic errors are the leading cause of loss in cardiology liability suits. Physicians could reduce loss by ruling out conditions carrying the greatest risk if misdiagnosed and by consulting with a radiologist concerning abnormal x-rays. Lack of documentation, poor physician communication, and adverse patient perception also lead to problems.

Adult↗
PubMed1989

Hemorrhage produces abnormalities in lymphocyte function and lymphokine generation.

Hemorrhage has been shown to produce abnormalities in lymphocyte function, particularly in the proliferative response to mitogens such as PHA and Con A. In order to better examine the hemorrhage-induced alterations in immune function, we determined the effects of blood loss in mice without any surgical manipulation on lymphocyte populations and subpopulations, cellular activation, and lymphokine production. Hemorrhage induced no changes in cell numbers in the spleen, thymus, lymph nodes, and bone marrow. No alterations in the relative percentages of B (B220+, mu+) and T (Lyt-1+, Lyt-2+, T3+, L3T4+) cell subpopulations were found in any organ after blood loss. Significant decreases in splenocyte proliferation in response to Con A, IL-2R expression and blast formation occurred after hemorrhage. IFN-gamma production increased 24 and 48 h post hemorrhage. Decreases in IL-2, IL-3, and IL-5 generation were present 2 h after blood loss. IL-2 production remained significantly decreased for 48 h posthemorrhage, then increased to more than twice normal levels 72 h posthemorrhage, and subsequently returned to prehemorrhage values. These results demonstrate that hemorrhage produces widespread alterations in immune function without affecting lymphocyte population and subpopulation numbers.

Animals↗
PubMed1989

Quantitative and qualitative fat analysis in human leg muscle of neuromuscular diseases by 1H MR spectroscopy in vivo.

1H MR spectra were recorded from human gastrocnemius muscle at 63.86 MHz using the body coil of the Signa scanner as transmitter and a 3-in. surface coil as receiver. The fat content of the muscle was quantified relative to that of water in a selected volume or slice. The fat/water ratio was 0.05-0.07 for normal muscle but increased to 0.5-6.0 in primary and secondary muscular disorders such as Duchenne and myotonic dystrophy, Charcot-Marie-Tooth and polio muscular atrophy, cerebral palsy, and spina bifida. In Werdnig-Hoffmann spinal atrophy the ratio was above 10. Water-suppressed and slice-selective 1H spectroscopy was used for qualitative analysis of fat. The 1H profile of gastrocnemius muscles between healthy individuals and patients with neuromuscular diseases showed two major differences. In the normal muscle spectra, the resonance from the -(CH2)n- protons at 1.6 ppm was the most pronounced, whereas in the diseased muscle spectra resonances also appeared between 1.1 and 1.4 ppm. Some diseased muscle spectra showed multiple resonances from -CH = CH- in polyunsaturated fatty acids between 5.5 and 7.0 ppm. The corresponding resonances from = CH-CH2-, 1.9-2.0 ppm, and = CH-CH2-CH =, 2.7-2.9 ppm, were also seen. These peaks are usually not detected in normal muscle.

Adipose Tissue↗
PubMed1989

Hemorrhage in mice produces alterations in B cell repertoires.

Multiple organ system failure secondary to infection is the major cause of late deaths after trauma and hemorrhage. The production by B cells of antibodies directed against bacterial antigens is an important component of host defenses. In order to determine the effects of hemorrhage on B cell function, we examined hemorrhage-induced alterations in available (clonal precursors) and actual (plasma cells) B cell repertoires in the course of an immune response toward bacterial antigens. Hemorrhage produced greater than twofold decreases in the absolute frequency and number of clonal precursors specific for the bacterial antigens dextran, levan, and pneumococcal polysaccharide type II. After blood loss, there were decreases in absolute frequency, but not in numbers, of clonal precursors capable of producing antibodies against the nonbacterial antigens ovalbumin and mouse transferrin. Immunization with the bacterial antigen levan within 24 hr of hemorrhage resulted in approximately 50% fewer levan-specific plasma cells than that seen in normal, unhemorrhaged mice. These results demonstrate that hemorrhage produces marked alterations in B cell repertoires, which may contribute to postinjury abnormalities in host defenses.

Animals↗
PubMed1989

Hemorrhage in mice induces alterations in immunoglobulin-secreting B cells.

Infections remain the major cause of late morbidity and mortality after hemorrhage, trauma, and burns. Abnormalities in immune response appear to play a major role in the increased susceptibility to infection in this setting. In the present study, the effect of hemorrhage on the numbers of splenic B cells and isotype-specific immunoglobulin(Ig)-secreting cells in mice was investigated. No changes in the total number of splenocytes or of splenic B cells were found after hemorrhage. Decreases of greater than 40% in the total number of Ig-producing cells as well as in the numbers of B cells secreting IgM, IgA, and IgG2b were found during the period of 2 to 96 h posthemorrhage. Subsequent increases in the numbers of cells secreting IgA, IgG1, IgG2a, and IgG3 were present 96 to 144 h after hemorrhage. Total serum Ig levels fell by approximately 40% 3 days after hemorrhage, and then returned to normal within 5 days posthemorrhage. These results demonstrate that hemorrhage produces marked alteration in B-cell populations and serum Ig levels.

Animals↗
PubMed1989

Cardiorespiratory effects of pressure controlled inverse ratio ventilation in severe respiratory failure.

Cardiorespiratory values were measured in nine patients with severe respiratory failure before and following initiation of pressure controlled inverse ratio ventilation (PC-IRV) at an inspiratory to expiratory ratio of 2:1. All patients showed increases in PaO2, with the mean PaO2 rising from 63 +/- 4 (mean +/- SEM) to 76 +/- 8 mm Hg. Peak inspiratory pressure fell from 44 +/- 4 to 39 +/- 2 cm H2O. There were no significant changes in any hemodynamic or oxygen metabolism variable associated with the institution of PC-IRV. In particular, no significant alteration in cardiac index, pulmonary artery pressures, oxygen delivery, oxygen consumption, or oxygen extraction ratio occurred with the use of PC-IRV. These results suggest that PC-IRV may be a useful ventilatory modality in the treatment of severe respiratory failure since it results in improvement in arterial oxygenation without any deterioration in hemodynamic or tissue oxygen metabolism parameters.

Adult↗
PubMed1989

Covalent change in the major intrinsic polypeptide (MIP26K) during cataract development in the streptozotocin-induced diabetic rat.

Antisera to synthetic peptides corresponding to residues 229-237, 252-259, and 256-263 have been used to quantitatively bind to the 19.5K, 24.0K, and 26.5K forms of the Major Intrinsic Polypeptide (MIP26K) of lens membrane from the streptozotocin-induced diabetic rat. The binding ratio of anti-229/anti-252 for the 19.5K component, and the binding ratio of anti-252/anti-256 for the 26.5K component, both increase only during the opacification process of the diabetic lens. Together, these results demonstrate that various forms of the MIP26K molecule undergo covalent modification during cataractogenesis of the diabetic rat lens, and that the degree of this change as monitored by binding of the anti-MIP26K peptide sera correlates with severity of the lens opacification.

Animals↗
PubMed1989

Insall proximal realignment for disorders of the patella.

Proximal realignment with standard lateral retinacular release (Insall operation) was performed on 35 knees with a follow-up time of two to 11 years. The results for chondromalacia patellae were satisfactory to excellent results in 20 of 23 knees (87%) at two years and in eight of 15 knees (55%) at five to 11 years. Satisfactory to excellent results in 11 of 12 knees (92%) were noted for recurrent patellar dislocation. This procedure should be reserved for advanced chondromalacia patellae (Grades III and IV) and recurrent patellar dislocation. Anatomic studies suggest that the pain relief was most likely due to a combination of patellar denervation and restoration of patellar congruence.

Adult↗
PubMed1988

The selective binding and transmigration of monocytes through the junctional complexes of human endothelium.

Human monocytes show a high affinity for vascular endothelium both in vitro and in vivo. To explore monocyte-endothelial interaction in greater detail, we have developed a new in vitro model for growth of human endothelial cells (EC). Human umbilical vein EC (HUVEC) cultured upon collagen gels form confluent monolayers of EC that bind silver at their intercellular border similar to cells in situ. Intercellular junctional structures, both adherens and tight junctions, were identified. In contrast, HUVEC grown on plastic surfaces did not stain with silver. The silver-staining characteristic of EC-collagen monolayers was reversible and related to their in vitro maturation and senescence. Silver staining of EC borders provided a grid by which the location of monocyte binding to the luminal surface of individual EC could be assessed. Using this technique, we found that monocytes preferentially bound to the margins of EC, in approximation to the silver-staining junctions. These results suggest that EC determinants recognized by monocytes occur in a unique topographical distribution on the apical face of EC. After binding, monocytes migrated through the EC monolayers at high basal rates. The lack of penetration of collagen gels in the absence of an EC monolayer suggested the generation of EC-specific chemotactic signal(s). Monocytes were observed to pass between EC without evidence of disruption of the monolayer. Silver stain remained present during all phases of migration, and under transmission electron microscopy, junctional complexes were found proximal to monocytes that had just completed their passage through the monolayer. After orientation to the basal surface of the EC monolayer, monocytes migrated randomly into the underlying collagen gel. Monocyte adherence, penetration, migration, and long term survival can be studied under these conditions.

Cell Adhesion↗
PubMed1988

Postoperative monitoring of conjunctival oxygen tension and temperature.

To define the utility of conjunctival temperature (Tcj) and conjunctival oxygen tension (PcjO2) monitoring during rewarming in the postoperative period, we measured serial Tcj, PcjO2 and PcjO2 index (PcjO2/PaO2) values in 10 patients after cardiac surgery. PcjO2 and PcjO2 index were markedly depressed at the low conjunctival temperatures recorded during the immediate postoperative period. As the patients' core and conjunctival temperatures increased, there was a concomitant, linear increase in PcjO2 and PcjO2 index for Tcj less than 33.5 degrees C. Two patients showed deviation from this temperature-related rise in PcjO2 and PcjO2 index, and both of these patients demonstrated physiologic deterioration associated with cardiac arrest or hypotension. These results indicate that monitoring of PcjO2 and Tcj can provide a continuous assessment of the adequacy of peripheral perfusion and oxygenation in the postoperative period.

Aged↗
PubMed1988

Conjunctival oxygen tension monitoring in emergency department patients.

Conjunctival oxygen tension (PcjO2) was sequentially monitored in 96 medical and surgical patients admitted to the emergency department resuscitation suite during a 6-month period. There were 28 patients with cardiac arrest, 44 with major trauma, and 24 with severe medical problems. A total of 2,392 PcjO2 data points were collected in these patients. In patients with cardiac arrest, PcjO2 showed changes in physiological condition as early as or earlier than measurement of vital signs. Measurement of PcjO2 and the finding of a PcjO2 index (PcjO2/PaO2) less than .5 in normotensive multiple trauma patients allowed rapid detection of hemorrhagic hypovolemia. In critically ill medical patients, low values for PcjO2 were found with hypoxemia as well as in conditions associated with decreased cardiac output and tissue oxygen delivery. These two conditions could be distinguished by measuring PaO2 and calculating the PcjO2 index; a PcjO2 index less than .5 was associated with diminished peripheral perfusion and cardiac output, and a PcjO2 index greater than .5 indicated hypoxemia without any compromise in cardiac output. In the group of critically ill surgical and medical patients included in this study, conjunctival oxygen monitoring provided clinically useful information not available from vital signs and permitted identification of physiological instability associated with abnormalities in peripheral tissue perfusion and oxygenation as early as or earlier than conventional monitoring methods.

Adult↗
PubMed1988

Late neuropsychologic status after childhood head trauma.

A neurologic and neuropsychologic test battery was administered to a sample of 35 children drawn from all those in a defined geographic area who had been hospitalized for head trauma before age 7 during the years 1970-1976. Examination was performed 3 1/2 to 10 years after injury, at age 6-15. Twelve subjects had been diagnosed at the time of injury as suffering moderate insult and had been referred to the metropolitan neurosurgical center, while twenty-three with only mild injury had been retained for observation in a local pediatric ward. The twelve with more severe insult were significantly inferior to the other subjects on the Block Design and Coding subtests of the revised Wechsler Intelligence Scale for Children. The Koppitz score of the Bender Test, the WISC-R scatter, the Benton Visual Retention Test, the GATB Motor Speed Test and the Bourdon-Wiersma Vigilance Test showed less diagnostic power and failed to distinguish between the group with more severe injury and that with less. A detailed and carefully scored neurologic examination also failed to distinguish between the two groups. The findings suggest that relatively common traumatic injury may be associated with detectable late cognitive deficit, and that some WISC-R subtests may be among the best measures for detecting such deficit.

Brain Injuries↗
PubMed1988

Effects of hemorrhagic serum on interleukin-2 generation and utilization.

Exposure of normal peripheral blood mononuclear cells (PBMCs) to serum obtained from hemorrhaged animals produces marked depression of mitogen-induced cellular proliferation. In order to examine the mechanism which underlies its suppressive action, the effects of hemorrhagic serum on the production and utilization of interleukin-2 (IL-2) by PBMCs in mitogen-stimulated cultures were investigated. The production of IL-2 by PBMCs obtained from normal animals was reduced by approximately 90% after these cells were washed with hemorrhagic serum for 60 sec at 0 degrees C. Cells cultured in hemorrhagic serum showed greater than 30% reduction in proliferative response to phytohemagglutinin, and no significant change in the degree of suppression was produced by adding recombinant IL-2 to the cell cultures. PBMCs cultured with recombinant IL-2 and hemorrhagic serum, but not mitogen, proliferated significantly less than did cells cultured with IL-2 and normal serum. These findings suggest that although hemorrhagic serum produces a marked decrease in IL-2 generation, the suppressive effects of hemorrhagic serum on mitogen-induced lymphocyte proliferation are not due to this decrease in IL-2 production.

Animals↗