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G Lindemann

Publications and source records attributed to G Lindemann.

At least 19 recordsLinked to original sources
PubMed2001

Cloning and characterization of human erythroid membrane-associated protein, human ERMAP.

We describe here the cloning and characterization of the human gene ERMAP, identified by subtractive hybridization using early and late gestation human fetal liver. By in situ hybridization, we found human ERMAP to be expressed not only in erythoid cells in fetal liver and adult bone marrow, but also in reticulocytes and circulating erythroblasts in 8-12-week fetal cord blood. The human ERMAP protein is predicted to contain a transmembrane segment and one extracellular immunoglobulin fold (IgV). The cytoplasmic region contains a highly conserved B30.2 motif, multiple consensus sequences for kinases, and post-Golgi sorting signals. The protein was localized to the cell surface as shown by an antibody specific for a peptide predicted from the IgV fold. The amino acid sequence of human ERMAP is highly homologous with that of mouse ERMAP, but differs in the number of extracellular immunoglobulin folds. Human ERMAP represents a new unique member of the rapidly growing B30.2 domain proteins.

Amino Acid Sequence↗
PubMed2001

Limited heat-shock protein 72 induction in Caco-2 cells by L-glutamine.

BACKGROUND/AIMS: L-glutamine (L-gln) is a conditionally essential amino acid which is consumed by certain tissues like the intestine in large amounts as energy source during critical illness. Apart from nutritive action, recent data suggest a link to heat-shock protein (hsp) induction. We investigated the effect of L-gln on hsp72 expression in the intestinal cell line Caco-2 under basal and heat-shock conditions and compared it with related amino acids. METHODS: Total cellular protein was extracted and separated by SDS-PAGE. Immunoblots were performed with anti-hsp72 followed by chemiluminescence detection and densitometric scanning. RESULTS: Following heat shock, hsp72 protein expression increased by 72 and 53% at 2 and 4 mmol/l L-gln, respectively, compared to heat shock alone (p < 0.05). Under basal conditions a limited increase occurred only at 8 mmol/l L-gln (p < 0.01). Levels remained unaffected when related amino acids including alanine, glutamate or glycine were supplemented under basal and heat-shock conditions. Similarly, the nonmetabolizable glutamine analogue DON or the toxic metabolite L-pyroglutamate did not induce hsp72. CONCLUSION: We conclude that the glutamine-mediated effect may be specifically attributed to the metabolic action of L-gln.

Alanine↗
PubMed2000

Evidence against a pivotal role of preformed antibodies in delayed rejection of a guinea pig-to-rat heart xenograft.

INTRODUCTION: Whereas the involvement of elicited xenoantibodies in delayed xenograft rejection is currently being substantiated, this study focuses on the role of the preformed fraction of xenoantibodies. METHODS: To check the influence of the latter, we combined pretransplant complement inactivation (cobra venom factor) and antibody reduction (plasmapheresis) in a guinea pig-to-rat heart transplant model. RESULTS: Antibody reduction on plasmapheresis before xenografting did not prolong delayed xenorejection in decomplemented rats, although the immunohistologic pattern lacked the immunoglobulin deposits along endothelial walls found in xenografts of merely decomplemented recipients. Astonishingly, plasmapheresis, if carried out 2 days before transplantation, almost tripled xenograft survival, although preformed antibody levels were completely restored and even rebounding at the time of grafting. The pattern and number of infiltrating cells did not differ in dependence of the timing of plasmapheresis nor did the proliferative response of lymphocytes in the mixed lymphocyte reaction differ. However, plasmapheresis led to a retarded decrease of the mononuclear cell tumor necrosis factor alpha secretory potential, which correlated well with a diminished immunohistologic staining of tumor necrosis factor alpha secreted by graft-infiltrating mononuclear cells. CONCLUSION: These findings argue against a pivotal role of preformed xenoantibodies in the pathomechanistic process of delayed xenograft rejection and challenge the therapeutic strategy to reduce preformed xenoantibody levels before xenotransplantation in complement-inactivated recipients.

Animals↗
PubMed1996

Omega-3 lipid infusion in a heart allotransplant model. Shift in fatty acid and lipid mediator profiles and prolongation of transplant survival.

BACKGROUND: omega-3 Fatty acids may have a major impact on immune responses involved in heart transplant rejection. We compared the effects of posttransplant intravenous supplementation with omega-3-rich versus omega-6-rich lipid emulsions on graft survival, plasma fatty acid profiles, and levels of arachidonic acid versus eicosapentaenoic acid-derived lipid mediators. METHODS AND RESULTS: Inbred PVG and Wistar-Kyoto rats were used as donors and recipients, respectively, in a model of heterotopic heart transplantation. Animals received 9 g/kg body wt per day of either fish oil-derived (n = 8) or soybean oil-derived fat (n = 7) in the form of a continuously infused lipid emulsion; controls were sham-infused with saline (n = 8). Graft rejection was assessed by loss of activity of the transplant. The fish oil-derived preparation but not that originating from soybean oil caused an increase in total and free plasma fatty acids. Substantial quantities of eicosapentaenoic acid and docosahexaenoic acid appeared in the free fatty acid fraction, surpassing those of arachidonic acid. Ex vivo stimulation of neutrophils with the Ca2+ ionophore A23187 demonstrated an increase in 5-series leukotriene (LT) generation in animals undergoing omega-3 lipid infusion (LTB5, omega-oxidation products of LTB5, LTA5 secretion), with 5-series/4-series LT ratios ranging between 0.08 and 0.36. Ratios of TX B3/B2 liberated from ex vivo stimulated platelets even approached 1:1 in omega-3 supplemented rats. Graft survival was 7.6 +/- 0.3 (mean +/- SEM) days in saline-infused, 10.4 +/- 0.7 in omega-6 lipid-infused, and 12.9 +/- 0.4 in omega-3 lipid-infused animals. CONCLUSIONS: Posttransplant intravenous alimentation with fish oil-derived lipid emulsions prolongs heart transplant survival in excess to omega-6 lipids. Profound changes in fatty acid profiles and lipid mediator generation may underlie this finding.

Animals↗
PubMed1985

[Tumor degeneration of an autogenous ovarian transplant].

At a woman, at that time only 27 years old, because of a one-sided ovarian tumour, the abdominal hysterectomy with the resection of both appendages had been carried out. At the same time the other ovary macroscopically without pathological findings had been implanted into the Retzius cavity, where later it degenerated tumourously like the histological picture of a cystoma serosum papilliferum proliferans. Since the resection of the second tumour, which was carried out 28 years after the first operation, there has been found no more manifestation of a tumour up to now.

Adult↗
PubMed1979

Calcium fluoride containing granules produced in vitro in rat bones.

Femurs and tibias of normal rats were fixed in 4% unbuffered solutions of glutaraldehyde or formaldehyde containing 1% NaF. Following washing, radiographically controlled demineralization was performed in 3.25% HNO3. Light microscopy and transmission electron microscopy revealed the presence of so-called fluoride granules in bone trabeculae, cartilage, cartilage remnants, bone cells, chondrocytes and in the bone marrow. Selected area diffraction indicated that the fluoride granules contained CaF2. X-ray diffraction analysis of non-demineralized NaF-fixed bones were negative for CaF2. The results are discussed and related to precipitation artifacts reported in demineralized hard tissues and to similar CaF2-containing granules observed in demineralized bones and incisors of rats given high doses of NaF in diet or drinking water.

Animals↗
PubMed1977

Prevalence of cleft uvula among 2,732 Danes.

A total of 2,732 patients at the Royal Dental College, Copenhagen, were studied for occurrence of cleft uvula. The prevalence was 1.13%, and the ratio of partial to total clefts was 30:1. From a comparison with results of previous studies, it is concluded that the prevalence of cleft uvula in the Danish population appears to be in the same range as in other white populations which have been studied.

Adolescent↗
PubMed1975

Calcium fluoride in demineralized bones from rats with experimental chronic fluorosis.

Thirteen male rats, 7 or 10 months old, were given 0.005% NaF in the diet or 0.025 NaF in the drinking water fro periods of 3 to 20 weeks. Femur/tibia bones were demineralized in 3.25% HNO3, the process being watched on radiographs. As soon as all radiopaque material representing mineralized bone had disappeared, demineralization was discontinued. In some instances the process was stopped while some radiopaque material was still present. Hematoxylin-eosin stained paraffin sections from all bones showed deep blue granules, fluoride granules. Transmission electron microscopy and selected area diffraction revealed that the fluoride granules contain microcrystalline CaF2. X-ray diffraction of hydrazine-deproteinated, demineralized fluorotic bones revealed the presence of CaF2 and a minor unidentified component. The results are discussed in relation to (1) the identity of the fluoride granules, and (2) their inconsistent presence in demineralized hard tissues.

Animals↗