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Biomedical subjects

H Wolf

Publications and source records attributed to H Wolf.

At least 667 records · Page 37Linked to original sources

The specificity of the microcytotoxicity assay for cell-mediated immunity in human bladder cancer.

Cytotoxicity of lymphocytes from T1 or T2 bladder cancer patients and patients with other diseases was tested in 44-hour microcytotoxicity assay against 3 different target cell lines: 1) HU 456, derived from human bladder carcinoma and established in our laboratory, 2) HU 609, a line derived from normal human bladder tissue and established in our laboratory and 3) SAOS-2, a human osteosarcoma cell line from the Memorial Sloan-Kettering Cancer Institute. Lymphocyte concentrations ranging from 7.8 time 10(4) to 2.5 times 10(6) lymphocytes per ml. were tested against each cell line. Lymphocytes from both groups of patients demonstrated a cytotoxicity against all 3 target cell lines, proportional to the lymphocyte concentration used. There was no difference in reactivity to HU 609 or to SAOS-2 between bladder cancer and control patients but the lymphocytes of bladder cancer patients showed a statistically greater cytotoxicity for HU 456, demonstrating a tumor type-specific cellular immune reaction superimposed on a background of non-specific cytotoxicity.

Antigen-Antibody Reactions↗

Pulvomycin, an inhibitor of protein biosynthesis preventing ternary complex formation between elongation factor Tu, GTP, and aminoacyl-tRNA.

Pulvomycin and the synonymous antibiotics labilomycin and 1063-Z are shown to inhibit prokaryotic protein synthesis by acting on elongation factor Tu (EF-Tu): in the presence of the antibiotic, the affinity of EF-Tu for guanine nucleotides is altered, the EF-Tu.GDP/GTP exchange is catalyzed, and the formation of the EF-Tu.GTP complex is stimulated. Hydrolysis of GTP by EF-Tu, induced by aminoacyl-tRNA, ribosomes, and mRNA or by kirromycin, is inhibited by pulvomycin. As shown by Millipore filtration, chromatographic analysis, and hydrolysis protection experiments, pulvomycin prevents interaction between aminoacyl-tRNA and EF-Tu.GTP to yield the ternary complex aminoacyl-tRNA.EF-Tu.GTP. Thus, enzymatic binding of aminoacyl-tRNA to ribosomes is blocked.

Aminoglycosides↗

The binding of kirromycin to elongation factor Tu. Structural alterations are responsible for the inhibitory action.

The influence of kirromycin on the elongation factor Tu (EF-Tu) in its binary and ternary complexes was investigated. The equilibrium constant for the binding of the antibiotic to EF-Tu . GDP and EF-Tu . GTP was determined by circular dichroism titrations to be 4 x 10(6) M-1, and to EF-Tu . GTP . aa-tRNA by a combination of circular dichroism titrations and hydrolysis protection experiments to be 2 x 10(6) M-1. In the presence of kirromycin the binding of aminoacyl-tRNAs to EF-Tu . GTP is weakened by a factor of two. The antibiotic changes the conformation of the ternary complex in such a way that the aminoacyl moiety of the aminoacyl-tRNA is more accessible to the non-enzymatic hydrolysis. It is concluded that this structural alteration is responsible for the inhibitory action of the antibiotic.

Anti-Bacterial Agents↗

Refluxing ureteral stump.

Two cases are presented of reflux into a residual ureter causing recurrent urinary tract infection. A voiding cysto-urethrogram should be included in the investigative routines when nephrectomy for unilateral chronic pyelonephritis is planned. If severe reflux is seen, the entire ureter should be removed along with the kidney.

Adult↗

[Development of a pediatric amino-acid solution for premature and newborn infants following pharmacokinetic principles].

The blood level kinetics of an amino-acid solution following short-term infusions was measured in 25 premature and 5 hypotrophic newborns. From the calculated transfer rates it was possible to compose an amino-acid solution capable of avoiding imbalances. Clinical tests showed that the solution was tolerated well. Balance studies in 10 premature infants demonstrated a positive nitrogen balance from the first day of life on with a 55% retention of administered amino-acid nitrogen.

Amino Acids↗

The regulations of gamma (structural) polypeptide synthesis in herpes simplex virus types 1 and 2 infected cells.

The polypeptides specified by herpes simplex viruses types 1 and 2 form at least three groups designated as alpha, beta and gamma. The structural polypeptides are largely contained in the gamma polypeptide group. In this study, we investigated the transition from beta to gamma polypeptide synthesis. Our data show the following: (i) gamma polypeptide synthesis in the presence of inhibitors of DNA synthesis in the presence of inhibitors of DNA synthesis is multiplicity-dependent. Some gamma polypeptides are not detectable in cells infected with 1 PFU per cell form a significant fraction of viral polypeptides in cells infected with 25--500 PFU per cell. (ii) The mRNAs specifying these polypeptides have a relatively short half-life as measured by the relative rate of decay of gamma polypeptide synthesis in infected cells following exposure to actinomycin D. Our data thus suggest that: (i) the transition from beta to gamma polypeptide synthesis does not require the synthesis of viral DNA; and (ii) the rate of synthesis of viral structural (gamma) polypeptides is linked to the size of the viral DNA pool as a consequence of a relatively short-lived mRNA.

DNA, Viral↗

[Liver diseases with microsomal antibodies. Frequency, clinical and immunological findings and course observations (author's transl)].

Microsomal antibodies (LKM-antibodies) differ in the indirect immunfluorescence by use of rat organ sections (kidney, stomach, and liver) from mitochondrial antibodies by there reaction with proximal renal tubules and hepatocytes while parietal cells usually fail to stain. In contrast to other humoral autoantibodies LKM-antibodies are rare. In a prospective study on 930 adults and 33 children with two third chronic hepatitis resp. cirrhosis frequency in the first group amounts to 0.38% and in the latter to 6.9% of all liver diseases. Among six patients with LKW-antibodies and chronic active hepatitis there were three children aged 4-13 and three adults between 45-55 years. On common results two children showed beside LKM-antibodies by absence of other immunphenomenons a rise of gamma-globulins in the electrophoresis and immunglobulin G as well as a chronic active hepatitis with necrosis leading in spite of initial rapid progression and persistent antibodies into inactive postnecrotiv cirrhosis. The other four patients showed no common course in respect to clinical, histological and immunological findings.

Adolescent↗

Progesterone in the uterus. VII. Uptake of cortisol and incorporation of progesterone under simultaneous application of cortisol into rat uterus.

After injection of radioactively labelled cortisol, the distribution of the radioactivity in the subcellular fractions of the rat uterus (nuclei, mitochondria, microsomes and 105 000 X g supernatant) was studied. In all fractions, radioactivity was observed and maxima were found 10, 20 and 50 min. after injection of the labelled hormone. Radioactivity was measured in all subcellular fractions even 180 min. after application of labelled cortisol. Additionally, radiolabelled progesterone and unlabelled cortisol in the ratio 1:1 or 1:2 (moles:moles) were injected into the animals. Studying the uptake of labelled progesterone in the subcellular fractions of the uterine tissue, revealed that no competition of unlabelled cortisol could be observed 10, 20 and 50 min. after application of the hormone mixture, compared with the control experiments. The results of this study give evidence that the progesterone uptake into rat uterus is specific and cannot be influenced by unlabelled cortisol.

Animals↗

Progesterone in the uterus. VIII. Uptake of corticosterone and incorporation of progesterone under concurrent injection of corticosterone into rat uterus.

A study of the subcellular distribution of radioactivity in rat uterus after injection of labelled corticosterone showed that the radioactivity was observed in all fractions from 5 min. to 120 min. A maximum uptake was observed 10 min. after application of the labelled steroid. Competitive uptake of radioactive progesterone and unlabelled corticosterone was assayed 10 min. after injection of the hormone mixture. The ratio between radioactive progesterone and unlabelled corticosterone was 1:1 and 1:2 (moles:moles), respectively. Compared with control experiments with rats which had received radioactive progesterone alone, the results gave evidence that progesterone found in all subcellular fractions and in the total homogenate was not depressed by unlabelled corticosterone. However, unlabelled progesterone reduced the tritiated progesterone in uterine tissue. This observation demonstrates that the uptake of progesterone by rat uterus is specific.

Animals↗

Elongation factor Tu resistant to kirromycin in an Escherichia coli mutant altered in both tuf genes.

A mutant of Escherichia coli is described that displays kirromycin resistance in a cell-free system by virtue of an altered elongation factor Tu (EF-Tu). In poly(U)-directed poly(Phe) synthesis the kirromycin resistance of the crystallized enzyme ranged between a factor of 80 and 700, depending on temperature. Similarly, kirromycin-induced EF-Tu GTPase activity uncoupled from ribosomes and aminoacyl-tRNA required correspondingly higher concentrations of the antibiotic. Resistance of EF-Tu to kirromycin is a consequence of a modified enzyme structure as indicated by its altered fingerprint pattern.P1 transduction experiments showed that the kirromycin-resistant EF-Tu is coded by an altered tufB gene (tufB1). The known existence of two genes coding for EF-Tu would interfere with the recognition of a mutant altered in only one of those genes, if the mutation were recessive. Because kirromycin blocks EF-Tu release from the ribosome, kirromycin sensitivity is dominant, as shown by the failure of a mixed EF-Tu population to express resistance in vitro. Therefore, phenotypic expression of kirromycin resistance in vivo appears to be only possible if the EF-Tu mutant lacks an active tufA gene, a property likely to be inherited from the parental D22 strain. The observations that introduction of a tufA(+) region makes the resistant strain sensitive to the antibiotic and that transduction of tufB1 into a recipient other than E. coli D22 yields kirromycin-sensitive progeny support these conclusions.

Anti-Bacterial Agents↗

Effect of tryptophan and nicotinamide loads on urinary excretion of RNA metabolites by bladder cancer patients.

In a comparative study of tryptophan metabolism and urinary excretion of nucleic acid derivatives (including beta-aminoisobutyric acid, 7-methylguanine, pseudouridine, and urate) in 12 male bladder cancer patients, the excretion of pseudouridine and 7-methylguanine decreased significantly after an oral dose of 2 g L-tryptophan. A similar decrease occurred after an oral nicotinamide load of 50 mg four times a day, which indicated a possible common mode of action of tryptophan and nicotinamide. No definite resolution could be made as to the causal mechanism for the observed descrase in RNA turnover.

Aminoisobutyric Acids↗