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Biomedical subjects

C Lange

Publications and source records attributed to C Lange.

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

Effect of lymphokine treatment on the invasion of cultured animal cells by Eimeria tenella.

Cultured animal cells were pretreated with crude cytokines from E. tenella-immune chicken spleen cells to determine whether the invasion of these cells by sporozoites of E. tenella could be affected. Treatment of both primary chicken kidney (CK) cells and the established Madin-Darby bovine kidney cell line (MDBK) with the crude avian cytokines caused an increased invasion of the cultures by the parasite. Apparently, the cytokine treatment of the cells increased the susceptibility or sensitivity of the host cells to invasion as evidenced by the increased number of the total cells infected and not by an increased number of sporozoites/infected cell. This increased host cell susceptibility to infection induced by the crude avian cytokines was: (a) dose-dependent; (b) non-host species specific, since it affected both avian and bovine cells; and (c) non-parasite species specific, since cytokines from E. tenella and E. maxima-immune chicken spleen cells and E. nieschulzi-immune rat spleen cells also increased the invasion of the CK and MDBK cells by E. tenella. However, treatment of MDBK cells with lymphokines induced from purified E. tenella-immune splenic T lymphocytes inhibited the invasion of the cells by E.tenella sporozoites. Therefore, the increased susceptibility of the host cells is caused by a B cell-or macrophage-mediated factor. Although the identity of the factor or factor(s) is unknown, this in vitro-lymphokine-E.tenella system should provide an excellent model to aid in the identification of cellular binding sites and/or penetration mechanisms for cellular invasion by the Eimeria.

Animals↗
PubMed1986

Assessment of vitamin D sulphate in human milk using desorption chemical ionization mass spectrometry.

Vitamin D3 sulphate (SD3) identification in human milk was obtained using Desorption Chemical Ionization (DCI). The chemical ionization reagent gas used was nitrogen, molecules were ionized when the emitter was heated. SD3 was obtained from lactarium human milk and purified by high-performance liquid chromatography (HPLC). A selected ion monitoring (SIM) measurement was carried out with typical ions, m/z 366 for SD3 and m/z 384 for parent vitamin D3, the intensity ratio (I366/I384) greater than 1 being related to the presence of the sulphoconjugated form of vitamin D3 in the sample analysed. The detection of small quantities of SD3 in human milk is possible using this technique.

Chemical Phenomena↗
PubMed1984

Acetylcholinesterase in cultured human leukemia/lymphoma cell lines.

Fifty-two cultured leukemia/lymphoma cell lines were studied for their acetylcholinesterase activity. There was a striking effect of maturity on enzyme activity, only the most mature cells showing significant activity. Mature T cells exhibited far more enzyme activity than mature B cells, paralleling results on normal T and B cells.

B-Lymphocytes↗
PubMed1983

Fibronectin and anchorage-independent and anchorage-dependent growth of benign and malignant cell lines.

The presence of fibronectin in three "malignant" (AU-471, AU-436, LT-2) and two "benign" (BHK-21, WI-38) cell lines was demonstrated with a fluorescent antibody technique; two malignant (AU-471, AU-436) cell lines were fibronectin-negative and one (LT-2) retained fibronectin expression. One "benign" cell line (WI-38) expressed fibronectin, the other (BHK-21) did not. Anchorage-independent soft agar (AISA) growth correlated better with loss of fibronectin than with malignant potential. All three fibronectin-negative cell lines (benign and malignant) grew anchorage-independently (AU-471, AU-436, BHK-21), and both fibronectin-positive cell lines were anchorage-dependent (LT-2, WI-38). Surprisingly, the addition of Clg to anchorage-independent cells increased their anchorage-independent soft-agar cloning efficiency, but had no effect on anchorage-dependent cell lines. Anti-Clg antibodies decreased AISA growth. The effect of Clg on anchorage-independent growth varied with the concentration, and also between cell lines, and a variation in effect was noted between anchorage-independent (AISA) and anchorage-dependent (in flasks) growth even in the same cell line.

Cell Line↗
PubMed1981

Distinction of the phenotypes of in vitro anchorage-independent soft-agar growth and in vivo tumorigenicity in the nude mouse.

The growth characteristics of LT-2 cells, an epithelial squamous cell carcinoma, clearly separate the phenotypes of anchorage-independent growth in soft agar and tumor formation in vivo. LT-2 readily grows and forms tumor nodules in the nude mouse but does not proliferate anchorage independently in soft agar. This distinction is confirmed by the observation that cells explanted from nude mouse tumor nodules and cultured in vitro still do not clone in soft agar. The human origin of tumor nodule cells was confirmed by karyotyping. LT-2 cells have an aneuploid karyotype which has persisted for 4.5 years in culture with considerable variation in chromosomal number. Passage through the nude mouse did not select for any "tumor" clone since marked chromosomal variation was still noted by cells explanted from tumor nodules. Tumor cells formed a well-differentiated skin with keratin formation in the nude mouse despite wide karotypic variations of cells and years of in vitro culture. Strict monolayer growth was noted by LT-2 cells when grown in culture flasks and also by cells explanted from tumor nodules, indicating that monolayer growth and nude mouse tumorigenicity are also separate phenotypes.

Agar↗
PubMed1975

[Pneumonia as a cause of death in children (author's transl)].

The yearly death-rate from pneumonia in children aged one month to 15 years has fallen in Schleswig-Holstein from 1.8 (1954-1958) to 0.6 per ten thousand (1969-1973). At the same time, total death-rate in the same age group has fallen from 14.5 to 9.3 per ten thousand children. The proportion of pneumonia in the total death-rate was 5.3% in 1971-1973, 1.6% in the first month of life and, after the sixteenth year, 2.3%. Pneumonia was in fourth place (after accident, malformation and neoplasm) as a cause of death in those more than one month old. The death-rate due to pneumonia had not fallen between 1954 and 1973, varying between 10% and 12%. While death-rate of "primary" pneumonia (without other underlying disease) had fallen from 5.7% (1954-1958) to 1.1% (1969-1973), the death-rate of "secondary" pneumonia rose from 16.8% to 21.4% during the same period. The total number of children aged between two months and 15 years treated for pneumonia fell by two thirds from 1954-1973 (1245 to 406). The incidence of "primary" pneumonia during the same period fell to about a quarter, that of "secondary" pneumonia to one half. The unsatisfactory result in the treatment of "secondary" pneumonia is probably due to the underlying primary disease or a weakening of defence mechanisms by treatment or the occurrence of unusual causative organisms (pneumocystis carinii, tubercle bacilli, Candida, Aspergillus), demonstrated only after death.

Adolescent↗
PubMedDate not supplied

Hepatocytic gene expression in cultured rat mesenchymal stem cells.

The origin of liver cells from distinct bone marrow stem cells, eg, hematopoietic stem cells or multipotent adult progenitor cells has been recently described using in vitro studies. Cell culture experiments revealed the key role of growth factors and the organ-specific environment for the induction of liver-specific genes. We investigated the in vitro potential of rat mesenchymal stem cells to differentiate into hepatocytic cells in cocultures with isolated rat liver cells. Rat mesenchymal stem cells (MSCs) propagated in culture, and transduced with green fluorescent protein (GFP) were cloned. Cells from selected clones were either cultured under liver-stimulating conditions, using serum free medium supplemented with HGF, EGF, SCF, and FGF-4 alone on fibronectin-coated surfaces, or cocultured with freshly isolated rat liver cells. Cocultured cells were harvested after two weeks and sorted into GFP-positive (GFP+) and GFP-negative (GFP-) cells. RT-PCR for liver specific markers CK-18 and albumin were performed on the different cell populations. After 2 weeks, the specified culture conditions led to the expression of albumin and CK-18 RNA in GFP-positive sorted MSCs from the cocultures, whereas MSCs cultured without liver cells did not express the studied genes. The results indicate, that when cocultured with liver cells MSCs from the bone marrow have the potential to differentiate toward hepatocytic cells in vitro. We conclude that MSC may possess an enhanced capacity to differentiate into functional liver cells. Additionally, environmental factors seem to be crucial for specific and directed differentiation.

Animals↗
PubMedDate not supplied

Low molecular thymic peptides stimulate human blood dendritic cells.

Dendritic cells are considered to be the most potent antigen-presenting cells and are thus promising new tools for the immunotherapy of cancer. They respond to various stimuli by differentiation (expression of CD83) and up-regulation of costimulatory surface molecules. Thymic peptides have immunostimulatory and immunomodulating properties. Their therapeutic potential in immunotherapy of cancer has been discussed. To test whether thymic peptides act on dendritic cells, we examined the effects of a standardized thymic peptide preparation on cultured human monocyte-derived dendritic cells. Addition of thymic peptides resulted in enhanced expression of the specific differentiation marker CD83 in a dose dependent manner. Moreover, thymic peptides induced the up-regulation of costimulatory molecules including CD86, CD80, HLA-DR and HLA-ABC. After priming with thymic peptides dendritic cells showed an enhanced expression of IL-8 and TNF-alpha mRNA and protein release. Dendritic cells stimulated with thymic peptides were able to induce proliferation of autologous T cells as measured by 3H-thymidine incorporation in mixed Lymphocyte reaction. In combination with a low dosage of keyhole limpet hemocyanin, thymic peptides showed additive effects in the up-regulation of CD83 and costimulatory surface markers. Our findings indicate that thymic peptides per se act on professional antigen-presenting cells in a stimulatory manner and were presented by these cells. Furthermore, thymic peptides enhance the response of dendritic cells to low dosages of a standard nominal antigen. Therefore, thymic peptides could improve the immunological activity especially against low amounts of endogenous antigens.

Amino Acid Sequence↗