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Biomedical subjects

G Franz

Publications and source records attributed to G Franz.

At least 73 records · Page 4Linked to original sources
PubMed1990

Absence of drug interaction between heparin and nitroglycerin. Randomized placebo-controlled crossover study.

The purpose of this randomized crossover study was to determine whether nitroglycerin interacts with heparin in terms of its anticoagulative properties as determined by activated partial thromboplastin time and thrombin time. Eight healthy adults were given either a 60-minute intravenous infusion of 5 mg of nitroglycerin or a 0.9% sodium chloride solution subsequent to the administration of an intravenous injection of 5000 U of heparin. No nitroglycerin-related drug interference with heparin was observed as measured by the activated partial thromboplastin time and the thrombin time.

Adult↗
PubMed1989

Molecular and genetic analysis of an embryonic gene, DC 8, from Daucus carota L.

To understand the morphogenetic and physiological processes occurring during plant embryogenesis, we isolated cDNA clones homologous to genes preferentially expressed during somatic embryogenesis. One of these cDNA clones detected an embryo-specific mRNA species with a corresponding protein of 66 kDa. The expression pattern of the mRNA is similar between somatic and zygotic embryos of carrots. To characterize the gene encoding this mRNA, we isolated the corresponding genomic clones. Molecular analysis of the DNA from several haploid and diploid carrots showed that the mRNA was encoded by a single copy gene, named DC 8. DNA sequence analysis showed that the gene consisted of three exons and coded for a hydrophilic protein with a central region composed of 17 repeats. At the NH2-terminus no typical signal sequence was found. Immunocytochemical analysis localized the protein primarily in the vacuoles and protein bodies of zygotic embryos; the cytoplasm showed some antibody staining. The protein was also found in cell walls of endosperm tissue. The amount of DC 8 protein was too low for it to be categorized as a seed storage protein; its role in embryo-genesis remains to be determined.

Alleles↗
PubMed1989

Polysaccharides in pharmacy: current applications and future concepts.

Polysaccharides constitute a structurally diverse class of biological macromolecules with a wide range of physicochemical properties, which are the basis for the different applications in the broad field of pharmacy and medicine. Besides the classical applications of these biopolymers in industry and pharmaceutical practice, the relatively new field of the physiologically active polymers will be discussed. Some examples will be given for the so-called immune-modulating antitumor polysaccharides which have been shown to be prominent candidates for an adjuvant tumor therapy.

Animals↗
PubMed1989

Chemical structure and biological activity of water-soluble polysaccharides from Cassia angustifolia leaves.

The water-soluble polysaccharides from Cassia angustifolia L. leaves were isolated and fractionated. The acidic polysaccharide fraction was separated into two subfractions S1 and S2 consisting of L-rhamnose, L-arabinose, D-galactose, and D-galacturonic acid. Further fractionation of the predominant S1 by GPC gave two fractions S1A and S1B with an average molecular weight of 2 x 10(6) and 1.5 x 10(5) d, respectively. Methylation analysis of S1A showed the presence of 1,4-linked galacturonic acid (31.0%), 1,2-linked rhamnose (14.5%), 1,2,4-linked rhamnose (15.8%), 1,3,6-linked galactose (15.3%), smaller amounts of 1,3-linked arabinose, 1.5-linked arabinose, and terminal galactose and arabinose residues. Mild acid hydrolysis of S1A indicated that the backbone consists of 1,4-linked galacturonic acid and 1,2-linked rhamnose residues in the ratio of 1:1. Every second rhamnose is connected via C-4 to arabinogalactan sidechains. The antitumor activity of the polysaccharide fractions was tested against the solid Sarcoma-180 in CD1 mice. Only S1A exhibited a significant antitumor activity with an inhibition rate of 51%.

Animals↗
PubMed1989

[Primary brain sarcomas].

The authors report on 79 cases of primary brain sarcomas, correlating clinical and pathoanatomical data. In the material analyzed the group of gliosarcomas prevailed, while the smallest group were rhabdomyosarcomas. In some groups the topic predilection did not show any specific characteristics, except that there were more gliosarcomas occurring in the parietal lobe. The symptoms lasted 1-3 months before operation.

Adult↗
PubMed1989

Biological response modifiers: their possibilities for cancer treatment.

Immunotherapy with the so-called 'Biological Response Modifiers' is based on the concept that the immune system can be activated to control neoplastic growth. Immunotherapy gained popularity as a treatment in the 1960's because of data from experimental tumor models. This indicated that mainly nonspecific stimulation with products of bacterial or fungal origine could prevent recurrence of, or delay growth of experimentally transplanted tumors. Since immunotherapy was most effective against relatively small tumors, clinical investigators began to view it mainly as a post-surgical treatment for a inhibition of micrometastasis. Mainly the activation of the non specific killer cells, macrophages and lymphocytes seems very promising to target an immune stimulant in the tumor site with a relatively high specificity. In the present study a whole series of biological polymers were tested in view of their capacity to enhance the immune system. However, the relatively small number of such compounds which can be applied therapeutically demonstrates that the ability of a compound to stimulate the immune systems is dependent on several conditions, such as the molecular dimension, the structure type and the solubility criteria. It will be shown that specific fungal glucans are very promising candidates for a successful cancer treatment.

Animals↗
PubMed1988

Developmental regulation of embryonic genes in plants.

Somatic embryogenesis from cultured carrot cells progresses through successive morphogenetic stages termed globular, heart, and torpedo. To understand the molecular mechanisms underlying plant embryogenesis, we isolated two genes differentially expressed during embryo development. The expression of these two genes is associated with heart-stage embryogenesis. By altering the culture conditions and examining their expressions in a developmental variant cell line, we found that these genes were controlled by the developmental program of embryogenesis and were not directly regulated by 2,4-dichlorophenoxyacetic acid, the growth regulator that promotes unorganized growth of cultured cells and suppresses embryo morphogenesis. These genes are also expressed in carrot zygotic embryos but not in seedlings or mature plants.

Journal Article↗
PubMed1986

Results of in vivo and in vitro studies for assessing prenatal toxicity.

Examples of a combined approach using in vivo as well as in vitro methods for the assessment of prenatal toxicity are presented. The topics discussed include the analysis of the possible embryotoxic potential of valproic acid (VPA), female sex hormones, bis(tri-n-butyltin) oxide (TBTO), and acyclovir and the problem of supplementing in vitro systems with drug-metabolizing activity.

Abnormalities, Drug-Induced↗
PubMed1985

Conservation of major nuclease S1-sensitive sites in the non-conserved spacer region of ribosomal DNA in Drosophila species.

We have analysed nuclease S1-sensitive sites in cloned ribosomal DNA repeats from Drosophila melanogaster, D. hydei and D. virilis. All species contain major S1-sensitive sites in the spacer near the region of transcription termination, albeit with somewhat different positions and sensitivities. The same sites are also sensitive to the single-strand specificity of Bal31 nuclease at neutral pH. Additional major sites exist at each end of the intervening sequence within the 28 S gene of non-transcribed intervening-sequence-positive ribosomal DNA units of D. hydei. Only minor sites, however, were detected in the Pol I promoter regions. This is in contrast to Pol II transcribed genes, where S1 hypersensitivity becomes apparent at the 5' ends during gene expression. We have sequenced and mapped the S1 sites in the D. hydei spacer. They consist mainly of alternating A and T nucleotides that could form small cruciform structures. Cross-hybridization at low stringencies between the relevant S1-sensitive spacer regions of the three species indicates that the sites lie within very divergent sequences. We discuss the potential functional significance of S1 sites in rDNA spacers and intervening sequences, and the manner in which they might be maintained during rDNA sequence divergence.

Animals↗
PubMed1985

[Results of the Hamburg ovarian blastoma study].

A randomized chemotherapy trial is forthwith reported on, in which therapy A (vincristine/ifosfamide/tegafur) was compared with therapy B (fluorouracil/trofosfamide/methotrexate/melphalan). Both patient groups received trofosfamide and oral progesterone as maintenance treatment until the end of the second therapy year. Forty-six patients were randomized into group A, 63 into group B. The evaluation of the survival curves suggests a division of the patients into 3 groups with different mortality risks.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Determination of the region of rDNA involved in polytenization in salivary glands of Drosophila hydei.

During the formation of polytene chromosomes in salivary glands of Drosophila hydei, the genes for ribosomal RNA (rDNA) are underreplicated relative to the rest of the genome. We have measured the number of rRNA genes with and without intervening sequences (ivs+ and ivs- genes) in polytene chromosomes of different genotypes. In the group of genotypes having a large number of ivs- rRNA genes polytenization only occurs within the cluster of ivs- genes. In each of these genotypes rDNA polytenization reaches a constant level of 150 ivs- genes per two chromatid sets (2C); X/X constitutions having two nucleolus organizers (NOs) in the diploid set polytenize the same amount of rDNA as X/O constitutions. In the group of genotypes with small ivs- gene numbers, the rDNA region involved in polytenization is longer and has an average length of 1,700 kb per NO, which is constant in these genotypes. Polytenization of rDNA is extended into the cluster of ivs+ genes, in spite of the fact that these genes appear to be nonfunctional. The smaller the number of ivs- genes, the greater the number of ivs+ genes that are polytenized in the NO. In these genotypes, X/X females replicate twice as much rDNA as X/O males, suggesting that both NOs of the diploid set are polytenized. A comparison of the pattern of spacer length heterogeneity in hybrids between different stocks also demonstrates that both NOs are replicated during polytenization.

Animals↗