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Biomedical subjects

M Schulz

Publications and source records attributed to M Schulz.

At least 163 records · Page 9Linked to original sources

Induction of UDP-Glucose:Salicylic Acid Glucosyltransferase in Oat Roots.

A UDP-glucose:salicylic acid 3-O-glucosyltransferase (EC 2.4.1.35) (GTase) from oat (Avena sativa L. cv Dal) root extracts was assayed in vitro using [(14)C]salicylic acid (SA) and an ion exchange column to separate SA from beta-glucosylsalicylic acid. The GTase, present at a very low constitutive level, was inducible to 23 times the constitutive level. When excised roots were exposed to SA at pH 6.5, the specific activity of the enzyme increased within 1.5 h, peaked after 8 to 10 h, and then declined. The increase in specific activity depended on the concentration of SA in the induction medium. Among 16 phenolics and phenolic derivatives tested, GTase induction showed high specificity toward SA and acetylsalicylic acid. Specific activity of the enzyme was induced to higher levels in roots from 7-d-old seedlings than roots from younger plants. GTase activity was less inducible in basal compared with median or apical root sections. Induction of GTase activity was a result of de novo RNA and protein synthesis. Candidate peptides for the GTase were identified by comparison of two-dimensional electrophoresis gels of proteins labeled with [(35)S]methionine during incubation of roots in the presence or the absence of SA and a gel of a partially purified GTase preparation.

Journal Article↗

Vaccination with a synthetic peptide modulates lymphocytic choriomeningitis virus-mediated immunopathology.

Vaccination with a nucleopeptide (NP 118; amino acids 118 to 132) representing a cytotoxic T-cell epitope of lymphocytic choriomeningitis virus (LCMV) can modulate immunopathology. Immunization with NP 118 protected H-2d mice against intracerebral infection with the LCMV-ARMSTRONG isolate. However, when NP 118-primed H-2d mice were challenged intracerebrally with an intermediate dose (5 x 10(4) PFU) of the LCMV-DOCILE strain, all mice primed with NP 118 emulsified in incomplete Freund's adjuvant died, whereas unprimed mice survived. Correspondingly, peptide vaccination enhanced specifically the cytotoxic T-cell response, influencing the critical balance between T-cell response and virus spread.

Animals↗

Inactivation of the thyrotropin releasing hormone.

Thyrotropin Releasing Hormone (TRH; pyroGlu-His-Pro-NH2) is rapidly hydrolyzed at the pyroGlu-His bond by a heterogeneously distributed ectoenzyme and a TRH-degrading serum enzyme. For these enzymes, the high degree of substrate specificity, the tissue specific hormonal regulation, the unusual tissue and the heterogenous cellular distribution strongly suggests that they serve very specialized functions for the transmission of TRH signals at specific target sites.

Animals↗

Peptide-induced antiviral protection by cytotoxic T cells.

A specific antiviral cytotoxic immune response in vivo could be induced by the subcutaneous injection of the T-cell epitope of the lymphocytic choriomeningitis virus (LCMV) nucleoprotein as an unmodified free synthetic peptide (Arg-Pro-Gln-Ala-Ser-Gly-Val-Tyr-Met-Gly-Asn-Leu-Thr-Ala-Gln) emulsified in incomplete Freund's adjuvant. This immunization rendered mice into a LCMV-specific protective state as shown by the inhibition of LCMV replication in spleens of such mice. The protection level of these mice correlated with the ability to respond to the peptide challenge by CD8+ virus-specific cytotoxic T cells. This is a direct demonstration that peptide vaccines can be antivirally protective in vivo, thus encouraging further search for appropriate mixtures of stable peptides that may be used as T-cell vaccines.

Amino Acid Sequence↗

Major histocompatibility complex binding and T cell recognition of a viral nonapeptide containing a minimal tetrapeptide.

The primary immune response of cytotoxic T lymphocytes in H-2d and H-2q mice to infection with lymphocytic choriomeningitis virus is directed mostly towards the common major T cell epitope of amino acids 112-132 on the viral nucleoprotein (NP). The molecules responsible for presentation of the T cell epitope NP112-132 are in both haplotypes the MHC class I L antigens (Ld, Lq). Truncations of the amino and carboxy termini of the NP 112-132 sequence revealed the nonapeptide RPQASGVYM (NP118-126) as a most effective peptide antigen, but even the tetrapeptide GVYM was recognized by CTL of both haplotypes in a class I antigen-restricted specificity. When tyrosine (Y) or methionine (M) were substituted with alanine, CTL recognition of the altered nonamer required 10(6) to 10(8) times higher peptide concentrations and in one case (Y----A on Ld) the peptide was not recognized at all. Up-modulation of the expression of Ld and Lq class I antigens as measured by flow cytometry correlated with the ability to present the peptide antigens. The only exception was peptide NP118-126 (M----A), which was recognized by T cells on L-Ld and L-Lq target cells but failed to up-regulate Ld and Lq antigens.

Amino Acid Sequence↗

[Therapeutic and toxic plasma concentrations and elimination half-lives of commonly used drugs].

For 253 frequently used drugs therapeutic and, if data were available, toxic, and fatal plasma concentrations as well as elimination half-lives were compiled in a table. To assess the significance of drug levels for the therapeutic monitoring of patients, it is essential that a collection of data is readily available. In addition, this list can assist the diagnostic assessment in case of intoxications.

Drug Therapy↗

Assessment of pretransplant prognosis in patients with cirrhosis.

The objective of this prospective study was to assess the prognostic value of dynamic liver function tests and traditional methods of evaluating liver function in potential candidates for hepatic transplantation. Patients who underwent orthotopic liver transplantation within the follow-up period of 120 days were excluded. The study included 107 adult and 57 pediatric patients with cirrhosis. Postnecrotic cirrhosis was present in 107 and biliary cirrhosis in 57 of 164 patients. During the follow-up period, 26 of 164 patients died of their liver disease. At the time of inclusion, we recorded monoethylglycinexylidide (MEGX) formation from lidocaine, indocyanine green (ICG) half-life, bilirubin and albumin serum concentration, activity of cholinesterase and alkaline phosphatase, prothrombin time, the clinical complication of ascites, and--in adults--the Pugh score also. These variables were subjected as covariates to a survival analysis (Cox proportional hazards regression model) using separately the data from adults, pediatric patients, all patients with postnecrotic cirrhosis, and all patients with biliary cirrhosis. In all of these four subgroups there was a significant relationship between MEGX and ICG test results and the 120-day survival. In the stepwise analysis, none of the remaining parameters contributed to a further relevant improvement of our predictive ability when added to the values of ICG and MEGX. Our results suggest that the ICG and the MEGX test are superior to conventional liver function tests and the Pugh score in assessing short-term prognosis in cirrhotics independently from the etiology of the underlying liver disease. These findings may have important implications for determining the optimum timing of transplantation.

Adolescent↗

Magnetic resonance imaging characteristics of multiple sclerosis plaques imaged with two-dimensional and three-dimensional Fourier transform techniques at low and mid field strengths.

A total of 58 multiple sclerosis lesions from 16 patients were used to characterize the performance of a low field system for the detection of edematous (e.g., water-elevating) brain lesions. Contrast, signal-to-noise, and their product (signal difference to noise) were measured for two-dimensional and three-dimensional Fourier transform techniques at low field strength (640 G) and compared to two-dimensional sequences at mid field strength (3,500 G). The results showed numerically that low-field strength magnetic resonance imaging can reliably detect multiple sclerosis lesions, and, by extension, other water-elevating lesions, although with lower confidence levels.

Adult↗

[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↗

Antiviral cytotoxic T cell response induced by in vivo priming with a free synthetic peptide.

Induction in vivo of antiviral cytotoxic T cell response was achieved in a MHC class I-dependent fashion by immunizing mice three times with a free unmodified 15-mer peptide derived from the nucleoprotein of lymphocytic choriomeningitis virus in IFA. The effector T cells are CD8+, restricted to the class I Ld allele of the analyzed mouse strain, and are specific both at the level of secondary restimulation in vitro and at the effector T cell level. These results suggest that cocktails of viral peptides may be used as antiviral T cell vaccines.

Amino Acid Sequence↗