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Biomedical subjects

I Beckman

Publications and source records attributed to I Beckman.

35 records · Page 2Linked to original sources
PubMed1988

Latissimus dorsi cardiomyoplasty: radiographic findings.

Left latissimus dorsi muscle cardiomyoplasty is a surgical procedure in which the muscle is mobilized as a pedicled flap, moved into the left pleural and mediastinal cavities, and used for surgical repair and/or mechanical augmentation of a failing left ventricle. Chest radiographs in four patients who had undergone this procedure were evaluated. In all four patients, there was bandlike or diffuse increase in density in the left midhemithorax with loss of the left heart border. These findings, which could be misinterpreted as lung disease, represent the transposed muscle flap. CT showed the exact anatomic position of the flap in relation to the intrathoracic structures. Familiarity with the postoperative radiographic appearance of this type of myoplasty is important to avoid misinterpretation.

Aged↗
PubMed1988

Specific inhibition of OKT3-driven T-cell mitogenesis by an anti HLA-class I monoclonal antibody.

Triggering of the T-cell receptor by anti-CD3 monoclonal antibodies (mAb), for example OKT3, induces accessory cell (AC)-dependent interleukin-2 (IL-2) and IL-2 receptor synthesis, and ultimately, T-cell proliferation. We report on the ability of a HLA-class I specific monomorphic mAb, namely FMC16, to inhibit OKT3-driven T-cell mitogenesis. FMC16 was apparently selective for OKT3 because it did not block Concanavalin A (Con A) or mAb Leu-4 induced proliferation. Moreover, this effect was not due to non-specific toxicity nor interference with OKT3 binding. Kinetic analysis showed that FMC16 was inhibitory when added up to 24 hr after initiation of culture. FMC16 drastically reduced both IL-2 production and IL-2 receptor expression, but did not interfere with IL-2 responsiveness. The inhibitory effects were not altered by the addition of exogenous IL-2 if FMC16 was present at the beginning of culture; however, IL-2 did restore proliferation if FMC16 was not added until 3 to 6 hr after initiation of culture. This coincided exactly with an IL-2 mediated increase in the level of TAC-positive cells. Furthermore, T-cell activation triggered by the synergistic action of OKT3 and a phorbol ester (TPA) in the absence of AC was also blocked by FMC16, suggesting that inhibition was not AC-dependent. Taken together, these results indicate that FMC16 interferes with early signals leading to IL-2 production and IL-2 receptor expression and suggest that HLA-class I determinants play an early role in T-cell activation.

Antibodies, Monoclonal↗
PubMed1987

Segmental absence of the aortic wall: magnetic resonance imaging sign of aneurysm.

A thin-walled, posttraumatic false aneurysm of the descending aorta in a 32-year-old man was obvious on chest radiography, computed tomography, and aortography. The wall of the aneurysm was not visualized on a magnetic resonance imaging study. However, a segmental absence of the lateral wall of the descending aorta indicated the level of the abnormality. This finding was not observed on 100 consecutive normal aortas studied with gated magnetic resonance imaging. It was observed in 2 of 50 normal aortas on nongated thoracic magnetic resonance imaging.

Adult↗
PubMed1987

Magnetic resonance imaging and intraoperative neurosonography in syringomyelia.

Treatment of syringomyelia remains a difficult and controversial problem. However, the recent advent of magnetic resonance imaging (MRI) and intraoperative ultrasound allows a more precise approach to the diagnosis and management of this disorder. Experience with 27 cases of syringomyelia has shown that MRI is superior to all other forms of diagnostic imaging for the exact anatomical delineation of syrinxes and other spinal cavities. One-third of the syrinxes demonstrated by MRI were either not adequately visualized or missed by myelography and/or computed tomographic scanning. Intraoperative ultrasound has been used to allow more precise operative approaches to the syrinx as well as to guide the exact placement of shunt tubes into syrinx cavities. A method has also been developed to allow intraoperative ultrasound of the spinal cord with patients in the sitting position.

Adult↗
PubMed1986

Low molecular weight IgM. Detection using immunoblotting.

Two techniques for the definitive identification of low molecular weight (LMW) IgM have been compared, namely, filtration chromatography combined with nephelometry and a modified immunoblotting assay. The results indicate that the latter is a more sensitive and reliable technique. Furthermore the resolution of immunoblotting is such that it can distinguish additional oligomeric forms of IgM as well as monomeric IgM suggesting a disorder of polymerization of pentameric IgM. As the presence of LMW IgM in the sera of patients with various disorders is of prognostic significance the immunoblot technique merits consideration as a useful screening assay to detect this moiety.

Arthritis, Rheumatoid↗
PubMed1985

Ultrasonographic findings in acute acalculous cholecystitis.

Acute acalculous cholecystitis (AAC) is usually seen as a complication of major surgery or trauma. Although this entity is well-known in the surgical literature, little has been written about it in the radiologic literature. A review of patient records from 1975 through 1982 revealed 16 patients with pathologically confirmed AAC on whom at least 1 sonographic study had been performed. Thickening of the gallbladder wall, a subserosal "halo" of edema, pericholecystic abscess, and marked gallbladder distention were consistent findings in AAC. In the proper clinical setting, these otherwise nonspecific findings allow a prompt and accurate diagnosis.

Acute Disease↗
PubMed1985

CT appearance of omental packs.

Liver lacerations may be surgically treated by using the omentum as packing. A radiologist can differentiate potential postoperative complications, such as abscess, hematoma, and biloma, from these packs on computed tomographic scans by noting attenuation values.

Adult↗
PubMed1980

Human lymphocyte markers defined by antibodies derived from somatic cell hybrids. I. A hybridoma secreting antibody against a marker specific for human B lymphocytes.

A hybridoma has been isolated from the products of fusion of a myeloma cell line with spleen cells from mice immunized with a human B cell line. After cloning, the hybridoma secretes antibody with the following properties: (i) Human B-lymphoblastoid cell lines react with the antibody while T and null cell lines do not. (ii) The antibody reacts with the majority of leucocytes in the blood of patients with CLL, but with a minority of cells in the blood of patients with AML or ALL of the null or T type. (iii) The antibody reacts with 9-21% of mononuclear cells in normal peripheral blood. The reacting cells are not T cells and overlap extensively with cells identified as B cells by other markers. The antigen identified by this antibody appears to be distinct from known B cell markers, and is put forward as a new B cell marker with diagnostic potential.

Animals↗
PubMedDate not supplied

Decreased proliferative capacity and increased susceptibility to activation-induced cell death in late-passage human CD4+ TCR2+ cultured T cell clones.

The growth characteristics in vitro of interleukin 2 (IL 2)-dependent human CD4+ alpha beta-T cell receptor-positive helper T cell clones (TCC) were studied in relation to alterations in surface phenotype, cytokine responsiveness, and susceptibility to activation-induced cell death (AICD). TCC derived from peripheral blood T cells had finite lifespans averaging 33 population doublings (PD) with a recorded maximum lifespan of 80 PD (n = 208). First analyses of the TCC were undertaken at ca. 25 PD, at which time all cells of all TCC expressed high intensity CD45RO and low intensity CD45RA, as well as high intensity CD95 (fas) and MHC class II antigens. The expression of these molecules remained elevated throughout the proliferative lifespan of the clones, but for those TCC which were initially CD28+ (the majority), the density of expression of the latter was diminished in most late-passage clones. Concomitant with this, late-passage cells showed reduced responsiveness to CD28-mediated costimulation by CHO transfectants expressing human CD80 compared to early-passage cells. Additionally, the level of expression of IL 2R gamma c and IL 7R chains was commonly reduced, as was the response to IL 2 and IL 7. Despite unchanged levels of fas expression on TCC with time, late-passage cells were more susceptible to AICD than early, passage cells. These observations further document functional and phenotypic alterations in long-term cultured human T helper cells, which may be considered as biomarkers of immunosenescence. This may contribute to an improved understanding of the mechanisms underlying depressed T cell function in old age.

Animals↗
PubMedDate not supplied

CT diagnosis of traumatic abdominal aortic rupture.

Blunt injury to the abdominal aorta has been previously reported. Due to the severity of the lesion, radiologic studies other than aortography are rarely undertaken prior to emergency surgery. We report a case in which CT initially demonstrated an angiographically and surgically proven rupture of the infrarenal abdominal aorta due to blunt trauma.

Adult↗