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Biomedical subjects

M Strauss

Publications and source records attributed to M Strauss.

At least 181 records · Page 10Linked to original sources
PubMed1989

Molecular cloning and characterization of the primary structure of the alkane hydroxylating cytochrome P-450 from the yeast Candida maltosa.

A cDNA library was established starting from poly(A) RNA of n-alkane-grown Candida maltosa cells and cDNA clones were isolated containing the entire coding sequence for the alkane hydroxylating cytochrome P-450. The deduced protein consists of 521 amino acids, contains two putative transmembrane segments in the N-terminal region and has a characteristic heme-binding sequence in the C-terminal part. Sequence alignments with members of 11 reported cytochrome P-450 families revealed a strong homology to an alkane-inducible cytochrome P-450 from Candida tropicalis.

Amino Acid Sequence↗
PubMed1989

Effect of a mammary-derived growth inhibitor on the expression of the oncogenes c-fos, c-myc and c-ras.

A mammary-derived growth inhibitor (MDGI) inhibits the resumption of growth of stationary Ehrlich ascites carcinoma (EAC) cells in vitro. The present study shows that the resumption of growth is accompanied by a rapid increase of the steady state mRNA level of the proto-oncogenes c-fos, c-myc and c-ras, which is reduced by MDGI. EAC cells from the exponential growth phase insensitive to MDGI did not show a reduced RNA expression. The effect of MDGI represents a novel activity at the level of gene expression and suggests a link to exist between growth inhibition and the reduction of c-fos, c-myc and c-ras expression.

Animals↗
PubMed1989

A phase I study of hepatic arterial infusion using difluoromethylornithine.

Ten patients with metastatic disease to the liver were treated with difluoromethylornithine (DFMO) administered by continuous hepatic arterial infusion. Two of nine evaluable patients had an objective partial response. Stable disease was recorded in three patients. Ototoxicity was encountered in all patients who received a daily dose of DFMO equal to or greater than 1.0 g/m2.

Adult↗
PubMed1989

Molecular cloning, sequencing and expression in Escherichia coli of the 25-kDa growth-related protein of Ehrlich ascites tumor and its homology to mammalian stress proteins.

The growth-related 25-kDa protein (p25) of Ehrlich ascites tumor (EAT) has been characterized by molecular cloning and sequencing of cDNA clones detected by hybridization with oligonucleotide probes synthesized according to the amino acid sequence of a tryptic peptide of p25. Detection of p25 mRNA in EAT of the exponential growth phase and of the stationary phase using cDNA-derived RNA probes demonstrated that the abundance of p25 mRNA is also growth-related. High-level expression of p25 in Escherichia coli has been established by oligonucleotide-directed mutagenesis of cDNA and insertion of the mutated cDNA into a T7-promoter expression vector. Recombinant p25 from the expressed cDNA sequence has been shown to comigrate with EAT p25 in electrophoresis and to react with antibodies against the EAT p25. On the amino acid level, p25 shows about 80% sequence homology to the human stress protein hsp27. Furthermore, p25 has similar isoforms of phosphorylation as demonstrated for small mammalian stress proteins from rat and human. From the results obtained, it is concluded that p25 is a mammalian stress protein, the abundance of which is related to growth characteristics of the Ehrlich ascites tumor.

Amino Acid Sequence↗
PubMed1989

Production of simian virus 40 large tumor antigen in bacteria: altered DNA-binding specificity and dna-replication activity of underphosphorylated large tumor antigen.

A bacterial expression system was used to produce simian virus 40 large tumor antigen (T antigen) in the absence of the extensive posttranslational modifications that occur in mammalian cells. Wild-type T antigen produced in bacteria retained a specific subset of the biochemical activities displayed by its mammalian counterpart. Escherichia coli T antigen functioned as a helicase and bound to DNA fragments containing either site I or the wild-type origin of replication in a manner identical to mammalian T antigen. However, T antigen purified from E. coli did not efficiently bind to site II, an essential cis element within the simian virus 40 origin of replication. It therefore could not unwind origin-containing plasmids or efficiently replicate simian virus 40 DNA in vitro. The ability of protein phosphorylation to modulate the intrinsic preference of full-length T antigen for either site I or site II is discussed.

Antigens, Polyomavirus Transforming↗
PubMed1989

Properties of the DNA-binding domain of the simian virus 40 large T antigen.

T antigen (Tag) from simian virus 40 binds specifically to two distinct sites in the viral origin of replication and to single-stranded DNA. Analysis of the protein domain responsible for these activities revealed the following. (i) The C-terminal boundary of the origin-specific and single-strand-specific DNA-binding domain is at or near amino acid 246; furthermore, the maximum of these DNA-binding activities coincides with a narrow C-terminal boundary, spanning 4 amino acids (246 to 249) and declines sharply in proteins with C termini which differ by a few (4 to 10) amino acids; (ii) a polypeptide spanning residues 132 to 246 of Tag is an independent domain responsible for origin-specific DNA binding and presumably for single-stranded DNA binding; and (iii) a comparison of identical N-terminal fragments of Tag purified from mammalian and bacterial cells revealed differential specificity and levels of activity between the two sources of protein. A role for posttranslational modification (phosphorylation) in controlling the DNA-binding activity of Tag is discussed.

Amino Acid Sequence↗
PubMed1989

The use of screws for maxillary denture fixation.

Stabilization of dentures or prostheses to the maxilla is necessary and desirable for trauma and maxillectomy patients. The use of screws from standard compression plating sets provides an inexpensive, simple, and well-tolerated means of achieving reliable fixation.

Bone Screws↗
PubMed1988

Condensation of vector DNA by the chromosomal protein HMG1 results in efficient transfection.

The aim of this study was the search for a method of vector packaging using natural chromatin constituents. The interaction of the chromosomal non-histone protein HMG1 with a vector plasmid (pLTEneo) was studied by sedimentation analysis and electron microscopy at physiological salt concentration. At high protein input the complexes exist in a condensed, monodisperse form sedimenting with 80 S irrespective of the supercoiled or relaxed conformation of DNA. Saturation binding is already observed at much lower input ratios. Dilution of 80 S complexes results in decondensation of the complexes. In the decondensed complex form, HMG1 binds in a bead-like manner to specific DNA regions. Condensation by HMG1 is sufficient to introduce the vector into mammalian cells without the need for unphysiological additives. The transfection rates were similar to or even higher than those obtained by the calcium phosphate coprecipitation technique.

Animals↗
PubMed1988

Reduction of oral flora with ciprofloxacin in healthy volunteers.

The effect of a short course of ciprofloxacin on the oral microflora was examined in 16 healthy volunteers. Salivary specimens were collected before and after two 750 mg doses of ciprofloxacin administered 12 h apart. Salivary bacteria were identified to species level, and total quantitative colony counts were determined for each isolate. For all 16 subjects, treatment with ciprofloxacin led to a reduction in total bacterial colony counts; the mean inhibitory activity was 94.9% (range 79.6-99.9%). Both aerobic and anaerobic bacteria were inhibited in every case: 72.5-99.9% for aerobes, mean inhibitory activity 93.5%; 75.0-99.9% for anaerobes, mean inhibitory activity 96.9%. Total counts were reduced by two or more logarithms in 75% of individuals for aerobes and anaerobes. All classes of bacteria were inhibited, with mean inhibitory activities ranging from 91.3% to 100%. These findings, together with the high salivary levels and low toxicity of ciprofloxacin, suggest clinical studies are required to assess its suitability in preoperative prophylaxis of patients undergoing head and neck cancer surgery.

Adolescent↗
PubMed1988

Neuropsychological and neuroradiological correlates in Huntington's disease.

Measurements of cortical and subcortical atrophy were made on CT scans of 34 patients with Huntington's disease. Significant correlations were found between the bicaudate ratio (BCR) and an eye movement scale (r = 0.44, p less than 0.01), and activities of daily living scale (r = 0.57, p less than 0.001) and the Mini-Mental State Exam (r = 0.49, p less than 0.01). No correlations were found between BCR values and severity of chorea or voluntary motor impairment. A detailed neuropsychological evaluation of 18 Huntington's disease patients showed significant correlations between the BCR and Symbol Digit Modalities test (r = 0.65, p less than 0.01), and parts A (r = 0.72, p less than 0.001) and B (r = 0.80, p less than 0.0001) of the Trail Making Test. These data support work in primates that demonstrates the role of the caudate nucleus in cognitive and oculomotor functions, but not in motor control (which is governed by putamino-subthalamic systems). The specific cognitive skills correlated with caudate atrophy in Huntington's disease are those reported in primate work to be served by the frontal-caudate loop system: eye movements, conceptual tracking, set shifting and psychomotor speed.

Adolescent↗
PubMed1988

Primary tissue cultures of benign and malignant human thyroid tumors: effect of TSH.

Many thyroid carcinomas seem to be dependent upon the thyroid growth-promoting properties of the thyroid stimulating hormone (TSH). The purpose of the present investigation was to compare the in vitro effect of TSH on tissue cultures derived from malignant and benign thyroid tumors. The results indicate that TSH can affect the morphology and protein synthesis of primary tissue cultures derived from benign and malignant thyroid tumors differently. The addition of TSH to cultures derived from benign tumors resulted in a reorganization of follicle-like structures of the monolayer and in a reduction of protein synthesis. In contrast to this, monolayers derived from carcinomas of the thyroid were not able to reorganize and their protein synthesis was not inhibited in the presence of TSH. For a better understanding of TSH suppressive therapy, we suggest testing the influence of TSH on a large number of tissue cultures derived from benign and malignant tumors of the thyroid.

Culture Techniques↗
PubMed1988

Hemilaryngectomy rescue surgery for radiation failure in early glottic carcinoma.

Radiotherapy for early glottic carcinoma has produced excellent results and low complication rates. Therefore, hemilaryngectomy and other forms of vertical partial laryngectomy have been used mainly for rescue therapy following radiation failure. Over a 9-year period selective application of this approach was used in eight patients out of 122 laryngeal cancer surgeries performed. Five patients were T1N0 and three were T2N0 at the time of initial diagnosis and at the time of recurrence. Three patients had healing problems postoperatively. Tracheal decannulation time was increased compared to patients who had hemilaryngectomy without previous radiotherapy. To date there has been no recurrence of carcinoma at any site with a mean follow-up of 58 months in surviving patients. This experience confirms reports which indicate that with careful selection, radiation failures for early glottic carcinoma can be rescued by hemilaryngectomy achieving excellent tumor control and moderately good preservation of laryngeal function.

Aged↗