Biomedical subjects

C Lorenz

Publications and source records attributed to C Lorenz.

16 recordsLinked to original sources

PubMed1992

The skeletal muscle chloride channel in dominant and recessive human myotonia.

Autosomal recessive generalized myotonia (Becker's disease) (GM) and autosomal dominant myotonia congenita (Thomsen's disease) (MC) are characterized by skeletal muscle stiffness that is a result of muscle membrane hyperexcitability. For both diseases, alterations in muscle chloride or sodium currents or both have been observed. A complementary DNA for a human skeletal muscle chloride channel (CLC-1) was cloned, physically localized on chromosome 7, and linked to the T cell receptor beta (TCRB) locus. Tight linkage of these two loci to GM and MC was found in German families. An unusual restriction site in the CLC-1 locus in two GM families identified a mutation associated with that disease, a phenylalanine-to-cysteine substitution in putative transmembrane domain D8. This suggests that different mutations in CLC-1 may cause dominant or recessive myotonia.

Amino Acid Sequence↗

PubMed1992

Specific in vitro O-glycosylation of human granulocyte-macrophage colony-stimulating-factor-derived peptides by O-glycosyltransferases of yeast and rat liver cells.

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is O-glycosylated at residues Ser9 and Thr10 during secretion by yeast and COS-1 cells [Ernst, J.F., Mermod, J.-J. and Richman, L.I. (1992) Eur. J. Biochem. 203, 663-667]. Two types of octapeptides encompassing residues 4-11 (peptide 4-11) and variants thereof, or residues 8-15 (peptide 8-15) of hGM-CSF were tested as substrates for in vitro O-glycosylation using dolichyl-phosphate- D-mannose: protein O-D-mannosyltransferase (Man-transferase) of the yeast Saccharomyces cerevisiae, or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) of rat liver cells. Peptide 8-15 was found to be O-glycosylated at residues Ser9 and Thr10 by GalNAc-transferase and, with reduced efficiency, also by Man-transferase. Peptide 4-11 was a good substrate for yeast Man-transferase, leading to mannosylation of only Thr10, whereas it was very poorly O-glycosylated at positions Ser5 and Ser7 by GalNAc-transferase. The observed differences in peptide-acceptor activities indicate that the site of O-glycosylation depends on similar, but not identical protein structural features in yeast and mammalian cells.

Amino Acid Sequence↗

PubMed1992

Evaluation of four automated hematology analyzers. A comparative study of differential counts (imprecision and inaccuracy).

The authors evaluated the performance of four modern, commercially available hematology analyzers for imprecision and inaccuracy in determining the leukocyte differential count. The evaluation was performed according to International Committee for Standardization in Haematology protocols and the National Committee for Clinical Laboratory Standards H20-T standard, using the same group of patients simultaneously. Imprecision was very low among all the analyzers for neutrophils and lymphocytes (coefficient of variation maximum = 4.12%), whereas for the other leukocyte populations it tended to increase as their presence percentage decreased. The imprecision of the analyzers was still lower than that of the microscopic method. The correlation with the manual 800 cell count (inaccuracy) was good for neutrophils, lymphocytes, and eosinophils (r = 0.974 to 0.888), less so for monocytes (r = 0.757 to 0.490), whereas it was poor for basophils (r = 0.532 to 0.078).

Adolescent↗

PubMed1991

Human immunodeficiency virus glycoprotein (gp120) infused into rat brain induces interleukin 1 to elevate pituitary-adrenal activity and decrease peripheral cellular immune responses.

Intracerebroventricular (i.c.v.) infusion of glycosylated recombinant gp120, the envelope protein of human immunodeficiency virus, in various doses (100 ng to 4 micrograms) resulted in detection of interleukin 1 (IL-1) activity in a high percentage (61%; 33 of 54) of rat brains, whereas IL-1 was very rarely detected in brains of animals infused with several control substances (4%; 1 of 28). To detect IL-1, clarified glial lysate of diencephalon plus brainstem was subjected to gel exclusion chromatography and fractions were assessed for thymocyte stimulation. IL-1 was seen 2, 6, and 24 hr postinfusion. i.c.v. gp120 also produced known effects of IL-1 in brain, elevating steroid concentration in plasma and decreasing cellular immune responses [natural killer (NK) cell activity and mitogenic response to Con A] of blood and splenic lymphocytes. When gp120 was infused together with alpha-melanocyte-stimulating hormone (20 ng), which blocks many biological actions of IL-1, gp120 no longer elevated steroids or decreased NK cell activity. After intravenous gp120, IL-1 was not found in brain or plasma, indicating that stimulation of IL-1 in brain by i.c.v. gp120 was not due to gp120 affecting infiltrating cells from blood or to elevated circulating IL-1. That induction of IL-1 in brain might have resulted from lipopolysaccharide (LPS) in the gp120 solution was ruled out by studies showing that (i) heating of the infusion solution, which does not affect the capacity of LPS to induce IL-1, eliminated the ability of gp120 infusion to induce brain IL-1, and (ii) gp120 induced IL-1 in brains of LPS-resistant C3H/HeJ mice. Injection of gp120 directly into the hippocampus stimulated IL-1 more readily than i.c.v. infusion. Thymocyte stimulation produced by active fractions of gp120-infused brains was blocked by monoclonal antibody to IL-1 receptors. These findings indicate that elevation of IL-1 in brain can result from infection with human immunodeficiency virus and may be responsible for certain abnormalities (e.g., elevated activity of pituitary-adrenal axis) seen in AIDS patients.

Animals↗

PubMed1991

[Therapeutic use of fresh plasma and "virus-safe" plasma].

The use of plasma and factor concentrates for the treatment of coagulation disorders is well established, but many questions remain. The indications for fresh frozen plasma are still not clearly established and excessive use is rampant. The safety of all blood products has not yet been firmly established. Peer review of transfusion practice in a hospital can be achieved by a Hospital Transfusion Committee. The review and analysis of the statistical reports of the transfusion service and strategies for enhancing quality of patient care will be presented.

Algorithms↗

PubMed1991

[Evaluation and objective assessment of the treatment course of burn injured children].

Between 1984 and 1989 70 out of 76 children, who underwent a primary inpatient treatment for thermal injury, had predominant second degree burns affecting 3 to 25% of body surface. Data of them, concerning epidemiology, first aid, run of inpatient and following outpatient therapy, were documented and summarised. All patients were physical examined and we judged functional and cosmetic results at least half a year after the injury. A uniform score allowed us a comparison of two different concepts of local therapy: closed treatment with impregnated gauze dressings vs. application of ointment (Flammacerium). Kind of documentation and score are proved to be of advantage in estimating run and results of treatment.

Adolescent↗

PubMed1990

[Changes in esophageal function caused by sclerotherapy of esophageal varices in children and adolescents with portal hypertension--a manometric study].

Morphological changes of the oesophageal wall, induced by injection sclerotherapy of oesophageal varices, may produce functional disturbances which are difficult to evaluate especially in children. Therefore manometric studies in 33 consecutive patients with portal hypertension (age: 2-18 years) were performed and functional parameters as of the oesophagus and oesophageal sphincter were recorded in different stages of treatment. The results were compared to findings in healthy children. From our studies we could conclude that functional disturbances seen in sclerolised patients must be set in relation to functional changes which we could see in patients without treatment of oesophageal varices. Endosclerosis affects essential parameters of oesophageal function; however, a large reversibility after termination of the treatment could be documented. The clinical relevance of the recorded findings and the diagnostic value of oesophageal manometry are discussed.

Adolescent↗

PubMed1990

[The use of homologous spongiosa chips in the treatment of juvenile bone cysts].

Juvenile bone cysts are characterized by trials of hypothetic interpretations in case of aetiology and general disagreement in relation to indicated therapy. The therapeutic spectrum is ranging from primary conservative treatment till subtotal e.g. total cyst resections. Because in juveniles a quantitative limitation for gathering of autogenous material exists the use of allogenous cancellous bone chips has a definitive place in treatment strategy.

Bone Cysts↗

PubMed1988

Posttranslational modification of interleukin-2 is a late event during activation of human T lymphocytes by ionophore A23187 and phorbol ester.

Human peripheral blood lymphocytes secrete high titers of interleukin-2 (IL-2) after stimulation by Ca2+-ionophore A23187/phorbol 12-myristate-13-acetate. During the first 30 hours of incubation cells secrete only the nonglycosylated IL-2 M form of the lymphokine, the glycosylated forms IL-2 N1,2 being detected only after prolonged culture times (30-48 h). After recultivation of cells for a second 48 h period (without additional mitogen), the glycosylated and nonglycosylated IL-2 forms are secreted at a constant ratio of 7:3 throughout. The detection of glycosylated IL-2 is parallelled by an increase in cellular glycosyltransferase activities involved in formation of sialylated oligosaccharides O-linked to proteins.

Calcimycin↗

PubMed1988

[Experiences with the use of cerium nitrate silver sulfadiazine in the local treatment of thermal injuries in childhood].

Ointment containing cerium nitrate and silver sulphadiazine (Flammacerium) was applied to 47 children with second-degree to third-degree thermal injuries, with something between five and 60 per cent of the body surface being affected, as had been reported in a one-year prospective study. This ointment proved to be superior to several alternative approaches with regard to local properties, antimicrobial effectiveness, and applicability to several degree of burns. The process of treatment can be optimised due to unproblematic applicability in open and closed variants under both hospitalised and outpatient conditions. This assessment has been underlined by good to very good therapeutic results.

Anti-Infective Agents, Local↗

PubMed1987