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Biomedical subjects

H Keller

Publications and source records attributed to H Keller.

475 records · Page 27Linked to original sources
PubMedDate not supplied

Carbohydrate-deficient transferrin is elevated in catabolic female patients.

Serum carbohydrate-deficient transferrin (CDT) is currently widely used as a biochemical marker of alcohol misuse. However, various recent studies have questioned the diagnostic value of this parameter and reported low levels of both specificity and sensitivity, especially in women. Thus, we sought to identify sub-groups of female individuals in which CDT is elevated independently of alcohol consumption. Significantly increased CDT levels were found in catabolic disease states due to psychiatric disorders distinct from alcoholism. None of those patients reported frequent alcohol consumption. CDT therefore appears also to be increased by metabolic processes distinct from alcohol degradation. Possible biochemical mechanisms of this phenomenon are discussed. As a consequence of these findings, the measurement of CDT alone is not suitable to screen for alcohol misuse in catabolic subjects.

Adult↗
PubMedDate not supplied

Noninavasive angiography for the diagnosis of carotid artery disease using Doppler ultrasound (carotid artery Doppler).

To detect stenosis in the carotid artery with a bidirectional continuous-wave Doppler ultrasound device, the following noninvasive procedure, applied on 800 patients and compared with 249 angiograms of 186 patients, has proved to be about 90% reliable. Measurements of flow signals were taken over the terminal branches of the ophthalmic artery (supratrochlear and supraorbital arteries) and averaged. Compression of superficial temporal and facial arteries revealed flow direction and common carotid artery compression revealed the supplying blood vessel and the effectiveness of the circle of Willis. Measurements over the common carotid arteries were used to evaluate peripheral resistance. A set of eight criteria was used; the diagnostic value of each criterion was calculated by comparing 138 pathological Doppler findings in 123 patients with the angiograms. If reverse flow direction in supratrochlear or supraorbital artery was used alone, only 43% correct diagnoses would have resulted. A more severe stenosis is not necessarily correlated with a more weighted criterion; a subset of criteria is less efficient than the combination of all criteria. Application during 32 extracranial endarterectomies on 28 patients informed the surgeon immediately about the hemodynamic effect of the surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Carotid Artery Diseases↗
PubMedDate not supplied

Phenotypical and functional characteristics of tumor-infiltrating lymphocytes from colon carcinomas stimulated with rIL-2 and rIL-4 in vitro: comparison with lymphocytes of the normal colon mucosa and the peripheral blood.

The phenotypical composition of tumor-infiltrating lymphocytes (TIL) from colorectal carcinomas was compared with that of intraepithelial lymphocytes of the autologous normal colon mucosa (IEL) and autologous peripheral blood lymphocytes (PBL). The CD4+/CD8+ ratios of the freshly isolated TIL, IEL and PBL were comparable and always > 1. CD25+, HLA-DR+ and CD56+ cells accumulated significantly in the TIL, while CD45RA+ cells were less frequent compared to the autologous IEL and PBL. CD29+ memory-cells were found with the highest frequency in the TIL. Stimulation with rIL-2 in vitro induced an outgrowth of CD56+ cells in the TIL. Concordantly the expression of CD3+ and the alpha/beta T-cell receptor was low. In a standard 51Cr-release assay these phenotypically LAK-cells representing effectors displayed an unspecific lytic activity against the autologous tumor as well as against allogeneic K562 and Daudi targets. The number of CD56+ cells could be reduced in TIL and PBL by simultaneous stimulation with rIL-2 and rIL-4, while the number of CD3+ cells increased.

Adult↗
PubMedDate not supplied

Shape changes and chemokinesis of Walker carcinosarcoma cells: effects of protein kinase inhibitors (HA-1004, polymyxin B, sangivamycin and tamoxifen) and an inhibitor of diacylglycerol kinase (R 59022).

Previous work has shown that PMA and diacylglycerols, activators of protein kinase C (PKC) can suppress cell polarity and locomotor activity of Walker carcinosarcoma cells in vitro, suggesting that PKC activation may result in a stop signal for tumor cell locomotion. This hypothesis was further analysed. The present results show that the DAG kinase inhibitor, R 59022, suppressed tumor cell polarity and strongly inhibited cell locomotion at a concentration of 10(-4), thus supporting the earlier finding that an increased availability of DAGs can suppress the locomotor activity of Walker carcinosarcoma cells. The results support the stop-signal hypothesis of PKC activation insofar as DAG kinase inhibition mimics the effects of DAGs and PMA. In order to clarify further the effects of protein kinase modulation on locomotion, we now extended our studies on structurally different inhibitors of protein kinases. In contrast to H-7, HA-1004 had no effect on cell polarity and did not reduce cell locomotion in the presence of colchicine, but reduced the proportion of spontaneously locomoting cells by 70% at 3 x 10(-4) M. Polymyxin B suppressed cell polarity and locomotion only at concentrations that proved to be toxic. Tamoxifen had no significant effect on cell polarity and locomotor activity. Sangivamycin did not suppress cell polarity and spontaneous locomotion at a concentration range of 10(-9) M to 10(-4) M. However, at 10(-4) M it decreased the proportion of migrating, colchicine-stimulated cells by 50%. The diverse responses to structurally different PKC inhibitors may be explained by their limited and variable specificity for PKC and different mechanisms of action on PKC.

Animals↗
PubMedDate not supplied

Phenotypical and functional differences of tumor-infiltrating lymphocytes from human colorectal cancers induced by costimulation with rIL-2 and rIL-4 in vitro.

The influence of recombinant human interleukin-4 (rIL-4) on the proliferation and cytotoxic activity of tumor-infiltrating lymphocytes (TIL) from human colorectal cancers was investigated TIL and peripheral blood lymphocytes (PBL) were cultured for 3-5 weeks. Under simultaneous stimulation with rIL-2 and rIL-4 the proliferation of TIL was less pronounced compared to stimulation with rIL-2 alone. In rIL-2 expanded TIL an outgrowth of CD56+ cells was observed. Concordantly, the expression of CD3+ cells was low. The number of CD56+ cells could be reduced significantly in TIL and PBL by stimulation with rIL-2 and rIL-4 simultaneously while the number of CD3+ cells increased. In TIL and PBL co-stimulation with rIL2 and rIL-4 resulted in higher CD4/CD8 ratios as compared to expansion with rIL-2 alone. In a 72 hour cytotoxicity assay the rIL-2/rIL-4 expanded TIL and PBL showed a lower lytic activity against autologous tumor targets in comparison to the rIL-2 expanded lymphocytes. In contrast, the cytotoxic activity of rIL-2/rIL-4 cultured TIL against allogeneic tumor cells was higher than in rIL-2 stimulated TIL.

Adult↗
PubMedDate not supplied

Expression of CD44, ICAM-1 and N-CAM in colorectal cancer. Correlation with the tumor stage and the phenotypical characteristics of tumor-infiltrating lymphocytes.

The cellular adhesion molecules (CAMs) CD44s, CD44v6, CD44v10, ICAM-1 and N-CAM were immunohistologically detected in colorectal cancers using the APAAP method. The expression of CD44s and CD44v6 was associated with the presence of lymph node metastases in the examined tumors. The pattern of ICAM-1 expression was inversely related to that of CD44, i.e. lower numbers of ICAM-1 positive cells were observed in metastasizing tumors. An intense focal staining of N-CAM was observed in the majority of the metastasizing tumors. The expression of CD44v, ICAM-1 or N-CAM on tumor cells did not correlate with the density of the tumor-infiltrating lymphocytes (TIL) within the tumors. The flowcytometric analysis of TIL showed a significant accumulation of CD25+ and HLA-DR+ cells and a reduced number of CD45RA+ cells as compared to autologous peripheral blood lymphocytes (PBL) or intraepithelial lymphocytes of the colon mucosa (IEL). These phenotypic characteristics of TIL did not correlate with the CAMexpression on tumor cells.

Adenocarcinoma↗