Search PubMed⌕ Search

Biomedical subjects

G Klein

Publications and source records attributed to G Klein.

At least 1,153 records · Page 64Linked to original sources
PubMed1975

Origin of lymphoid lines established from mixed cultures of cord-blood lymphocytes and explants from infectious mononucleosis, Burkitt lymphoma and healthy donors.

Lymphocytes were explanted from EBV-seropositive donors including peripheral blood of infectious mononucleosis patients, healthy donors and EBV-genome-carrying cells from Burkitt lymphoma (BL) biopsies or nude mouse-passaged, BL-biopsy-derived lines. The explanted cells were mixed with fresh cord-blood lymphocytes from mice of the opposite sex. In all categories of derived lines, cord-blood cell progeny was predominant, as judged by the sex marker and other associated markers. Only one BL biopsy line, serially passaged in nude mice, gave rise to a monoclonal lymphoma line.

Animals↗
PubMed1975

[X-ray studies of the brain as a basis for stereotaxy (author's transl)].

All attempts to reconstruct the topography of the brain in the living from studies of animal material are handicapped by technical difficulties. The best method is to compare exact X-ray pictures, which have been taken under stereotactic conditions. From a large collection of such X-rays the authors have composed contours of the internal table of the skull and of the ventricles, which best match the brains, selected for the Schaltenbrand-Bailey sterotactic atlas. For practical purposes these contours were combined with the transparent overlays for the nomenclature and the border lines of the different parts of the basal ganglia, which have been used in the myelin sections part of the atlas. A comparison of our sagittal series with the new X-ray findings shows, that the sagittal schemata of the atlas represent an extreme variation in the position of the Meynert axis and of the contours of the 4th ventricle. We have chosen a new axis system for the hindbrain, which corresponds to the average of our brains in constructing a new set of typical overlays for the atlas. The contour of the posterior fossa had to be completed. An independent axis system dor the structures of the 4th ventricle was developed, consisting of the base of the 4th ventricle, and a tangent, to the upper contour of the pons. In sterotactic procedures the axis systems for the forebrain and the hindbrain should be used independently. The results obtained are the basis for a new series of lantern slides which can be projected against the X-ray pictures with the Würzburg stereotactic equipment. In the course of this investigation we discovered a source of error. When air enters the puncture hole of the dura, the brain may sink back, so with the patient lying on his back, all structures may shift a few millimeters towards the occipital region. When the patient is lying on his side, as during an approach to the amygdala through the planum temporale, the ventricular system may collapse, so that almost no air is visible in the ventricles and the 3rd ventricle may appear to be in the lower hemisphere, the dislocation being more than 5-8 mm. But filling the ventricle with air through the ventricular catheter is sufficient to blow up the brain and to restore the normal topography.

Brain↗
PubMed1975

Comparative in vitro sensitivity of twom methylcholanthrene-induced murine sarcoma lines to humoral and cellular immune cytotoxicity.

MC57M and G are the tissue-culture derivatives of two methylcholanthrene-induced murine C57Bl sarcomas. Their sensitivity to immune cytoxic3, cytostatic or cytolytic spleen cells and sera was compared in parallel in vitro assays. The level of cross-reactivity displayed by the two lines was found to depend on the nature of the immune effector rather than on the assay which was used. It was high with immune spleen lymphocytes, alone or in the presence of decomplemented antisera, and low with antisera in the presence of rabbit complement. MC57G cells were more sensitive than MC57M cells to both effectors. Both cell lines were insensitive to antibody-dependent cell-mediated cytotoxicity. Preliminary evidence is presented, suggesting a probable involvement of embryonic and Moloney leukemia virus-induced cell surface antigens in the vitro sensitization of the two tumor lines to immune sera.

Animals↗
PubMed1975

Production by EBV infection of an EBNA-positive subline from an EBNA-negative human lymphoma cell line without detectable EBV DNA.

A continuous lymphoma cell line, BJAB, derived from the tumour of an exceptional African case of Burkitt's lymphoma, has previously been described. Unlike 97% of African BL cases studied, neither the original tumour cells nor the cell line contained detectable amounts of EBV (Epstein-Barr virus) DNA, nor did they express the EBV-determined nuclear antigen EBNA. The cells of the established line had the characteristics of B-type lymphocytes and they carried receptors for EBV. EBNA was induced in the majority of BJAB cells after EBV infection. Usually the cells died within 10 days of infection, but it was possible to establish a permanent EBNA-positive variant (GC-BJAB) of BJAB. The patient from whose tumour the original BJAB line was established was seropositive for EBV antigens, indicating previous exposure to and continuing presence of the virus; yet the tumour had not become infected by EBV. This evidence shows that EBV is not readily "picked up" by the lymphoma.

Antigens, Neoplasm↗
PubMed1975

Are methylcholanthrene-induced sarcoma-associated, rejection-inducing (TSTA) antigens, modified forms of H-2 or linked determinants?

TA3Ha/MSWBS hybrid cells have been derived from the fusion of the TA3Ha ascites carcinoma (H-2a) and the methylcholanthrene-induced MSWBS ascites sarcoma (H-2s). MSWBS expresses a strong tumor-specific transplantation antigen (TSTA), capable of inducing a rejection reaction in the syngeneic A.SW host. The genetic determinants of the H-2 complex are known to be localized on chromosome No. 17. TA3Ha contributes two normal, telocentric chromosomes No. 17 to the hybrid. In contrast, both chromosomes No. 17 of MSWBS are localized on readily identifiable translocations (17/1 and 17/M1 ; see Wiener et al., 1974). We have previously shown that the chromosomes No. 17 of one parental strain, or the other (but not both) can be removed from the hybrid by selective passage in the opposite parental strain. The present paper examined the possibility, often suggested in the literature, that the MC-sarcoma-associated TSTA could be a modified form of H-2. MSWBS, unselected TA3Ha/MSWBS and YACIR/MSWBS hybrids were compared with TA3Ha/MSWBS-derived isoantigen loss variants, with regard to their immunogenicity in the TSTA test, i.e. their ability to induce rejection of MSWBS target cells in ASW mice. Whereas the unselected hybrids were as immunogenic as the parental MSWBS line itself, two strain A compatible and two strain A.SW compatible variants which had lost chromosome No. 17 of the opposite strain showed a residual, but clearly weakened immunogenicity. Since there was no systematic difference between the reciprocal types, it is concluded that the genetic determinant of TSTA is not localized on the chromosome No. 17 but that a proper balance of this chromosome is required for the full expression of immunogenicity in the TSTA system.

Animals↗
PubMed1975

Genetic variation of in vitro cytolytic activity and in vivo rejection potential of non-immunized semi-syngeneic mice against a mouse lymphoma line.

Spleens of normal young mice of certain genotypes contain lymphocytes that can kill strain A-derived YAC-1 and some other in vitro-grown Moloney lymphoma lines in a 51Cr-release cytotoxic test. We have previously shown that mouse strains can be classified as high or low reactors in this test. F(1) hybrids between low- and high-reactive strains are high-reactive. In the present study, strain-A mice and eight different A F(1) hybrids were tested in parallel for their spleen-cell-mediated killing effect in vitro and their ability to reject graded numbers of YAC ascites or in vitro cultivated cells in vivo. There was a clear correlation between in vitro cytotoxicity and in vivo rejection in all tested genotypes. In segregating (A times C57Bl) times A backcross mice, in vivo rejection of YAC cells was H-2 linked. This is in line with the earlier backcross analysis of the in vitro cytotoxicity, suggesting a polygenic control with at least one H-2 linked factor.

Animals↗
PubMed1975

Classification of lymphocytes in nasopharyngeal carcinoma (NPC) biopsies.

Seven biopsies taken from nasopharyngeal carcinoma tissues were analyzed with regard to infiltrating B or T lymphocytes. The vast majority of these cells had the capacity to form SRBC rosettes (mean 87%) and were thus classified as T cells. Varying proportions of these were blast-transformed suggesting that they represented a host response against the tumor.

B-Lymphocytes↗
PubMed1975

[The value of pyrophosphate scintigraphy for the assessment of the activity of spondylarthritis ankylopoietica (author's transl)].

Seriological and scintigraphic activity was compared in 29 patients with spondylarthritis ankylopoietica (Bechterew's disease). Among our cases, 11 serologically active patients also had positive scans. the details being: cervical vertebral column in 5, thoracic vertebral column in 7 cases and the lumbar vertebral column and iliosacral joint in all 11 patients. In the group of 16 serologically inactive patients, 12 cases could be confirmed radiologically, in the remaining 4 early detection of ankylosing spondylarthritis was possible from the scintigraphic findings in combination with the clinical symptoms. The clinically suspected diagnosis of an incipient Bechterew's disease could not be justified in the remaining 2 patients who had no positive scintigraphic or serological results.

Adolescent↗
PubMed1975

Immunofluorescence and anti-complement immunofluorescence absorption tests for quantitation of Epstein-Barr virus-associated antigens.

Immunofluorescence absorption methods are described which permit quantitative estimation and differentiation of Epstein-Barr virus (EBV)-associated antigens (virus capsid antigen, VCA, early antigen, EA and EBV-determined nuclear antigen, EBNA) in cell extracts. EBNA was present in all cell lines (producer and non-producer) which carried the EBV-genome, while VCA and EA were present in producer lines only. All the antigens were absent from a lymphoid cell line (MOLT-4) which lacked the EBV-genome, as well as from leukemia cells from peripheral blood. The techniques demonstrated antigenic identity of the various antigens when prepared from different cell lines.

Absorption↗
PubMed1975

Studies of Epstein-Barr virus (ebv)-associated nuclear antigen. I. assay in human lymphoblastoid cell lines by direct and indirect determination of 125I-IgG binding.

A quantitative assay for EBNA in human lymphoblastiod cell lines has been developed. The assay employs EBNA-positive and -negative 125-I-IgG preparations as reagents and can be used in a direct or indirect manner. EBNA specificity has been demonstrated in a number of ways. The antigenic relationship between EBNA present in Raji cells and in a number of other human lymphoblastiod cell lines of diverse origins and between the cell-associated antigen present in FT Raji cells and that present in isolated Raji nuclei has been studied. The possibility of carrying out blocking titrations for anti-EBNA determination has been demonstrated and the effect of glutaraldehyde and formaldehyde upon antigenic activity in FT Raji cells has been studied.

Antigens, Viral↗