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Biomedical subjects

A Kiss

Publications and source records attributed to A Kiss.

At least 325 records · Page 18Linked to original sources

Effect of acute stress on catecholamine content in the hypothalamic nuclei of Japanese quail.

Concentration of noradrenaline, adrenaline and dopamine in eight hypothalamic nuclei or areas (nucleus hypothalamicus medialis anterior, n. periventricularis magnocellularis, n. hypothalamicus lateralis anterior, n. hypothalamicus medialis posterior, n. hypothalamicus lateralis posterior, eminentia medialis, n. tuberis, area hypothalamica posterior) have been determined by a sensitive radioenzymatic micromethod in male Japanese quail restrained for 30 min. In control quail the highest concentrations were found in the a. hypothalamica posterior, n. periventricularis magnocellularis and n. hypothalamicus medialis anterior; the lowest was in the n. hypothalamicus medialis posterior. After restraint, noradrenaline concentrations decreased in the n. periventricularis magnocellularis and n. hypothalamicus medialis posterior. However, the concentration of adrenaline increased in the n. tuberis under the same conditions. In stressed animals the dopamine concentration was lower than in controls in the n. periventicularis and higher in the n. tuberis.

Animals↗

Cellular and humoral cytotoxicity in patients with leukaemia and preleukaemia. II. Oncovirus specificity of the reaction.

Cytotoxic activities of lymphocytes and antibodies against autologous tumour cells detected by 51Cr release technique were frequent in patients with chronic granulocytic leukaemia, but infrequent in patients with blastosis of acute myeloid leukaemia. Among subjects with potentially preleukaemic haematological disorders autologous cytotoxic activity was observed only in cases of cytopenia, while samples from patients with polycythaemia vera proved to be devoid of cellular and humoral cytotoxicity. In the majority of cases the cytotoxic activity of lymphocytes and antibodies could be blocked by gp70 antigens of baboon endogenous virus (BaEV) and gibbon ape leukaemia virus (GaLV). p15(E) antigens of BaEV and GaLV showed blocking activity less frequently. Digestion by glycosidase of the carbohydrate of gp70 antigens reduced their blocking activity.

Animals↗

Natural antibodies to simian type-C viruses and human retrovirus HTLV in patients with lymphoid malignancies.

Blood plasma samples from adult patients and children with malignant lymphoproliferative diseases were studied for presence of antibodies to primate type-C viruses by membrane immunofluorescence. Antibodies to baboon endogenous virus could be detected in various types of lymphoid leukaemias and lymphomas. Gibbon ape leukaemia virus-specific antibodies were mainly found in B- and O-cell leukaemias and lymphomas. Anti-HTLV antibodies could be detected only in a few cases of T-cell malignancy. There was no evidence of a horizontal transmission of such viruses.

Adolescent↗

Studies on the specificity of human antibodies reacting with GP70 and P15 antigens of baboon endogenous (BaEV) and gibbon ape leukaemia (GaLV) viruses.

Antibodies reacting with gp70 and p15 antigens of baboon endogenous virus (BaEV) and gibbon ape leukaemia virus (GaLV) were detected by radioimmunoprecipitation (RIP) in blood plasma samples of patients with chronic granulocytic leukaemia, acute myeloid leukaemia and with potentially preleukaemic haematological disorders. Anti-gp70 antibodies were found more frequently than anti-p15 antibodies. Digestion of the carbohydrate part of gp70 antigens by glycosidase treatment abrogated the precipitation mediated by IgM antibodies, whereas that mediated by IgG antibodies was not markedly affected. Data suggest that antibodies detected in human plasma samples may have oncovirus specificity, but in considerable part of cases they can be of heterophil nature.

Animals↗

Study of cell-surface markers in chronic lymphocytic leukaemia (CLL).

There are new possibilities to characterize lymphocytes of the so-called immunoproliferative disorders, e.g. chronic lymphocytic leukaemia. Cell marker studies help to phenotype and differentiate several entities within the CLL-syndrome. Test of rosette formation with mouse erythrocytes together with the surface membrane immunoglobulin detection by immunofluorescence technique proved to be very useful in diagnosing B-CLL and in distinguishing it from other B-lymphoproliferative disorders. In three patients with atypical B-CLL the number of dual-marked (D)-lymphocytes were increased significantly. The prognostic value of this phenomenon is still uncertain.

Animals↗

Inhibition of doxorubicin-induced liver toxicity by a new dihydroquinoline type antioxidant.

The influence of a new dihydroquinoline type antioxidant on doxorubicin-induced hepatic toxicity was studied in mice (CFLP, LATI). Four groups of mice were studied: control, doxorubicin-treated, 5,6-methylen-bis (2,2,4/-trimethyl-1,2-dihydroquinoline/-disulphate (MDS)-treated, as well as doxorubicin and MDS-treated groups. Doxorubicin (15 mg/kg) was administered intraperitoneally, the MDS solution was given by a gastric tube. Liver function was assessed by the serum glutaminic-oxaloacetic-transaminase (SGOT) reaction. The lipid peroxidation in liver tissue was determined by the rate of malondialdehyd (MDA) production, the permeability of the liver lysosomal membrane was established by measuring beta-glucuronidase activity and its release from the cells. The MDS treatment proved to be effective in significantly reducing SGOT elevation, MDA production and lysosomal membrane damage in hepatic tissue. Clinical trials seem to be justified in using antioxidative substances to control doxorubicin toxicity.

Animals↗

Effect of cyanidanol-3 on lysosomal enzyme activity of serum and granulocytes in chronic liver disease and active hepatitis.

The authors examined the effect in vivo and in vitro of Catergen (cyanidanol-3) on demonstrable lysosomal enzyme activity in the serum and granulocytes in liver diseases. Acid phosphatase, cathepsin-D and beta-glucuronidase were investigated. In the in vitro studies the direct effect of Catergen was observed by enzyme release. In chronic active hepatitis without treatment the lysosomal activity of the serum increases, the lysosomal activity of the granulocytes decreases and in vitro release increases. Under the effects of Catergen treatment the lysosomal activity of the serum decreases in comparison with initial values, approaching the lysosomal enzyme activity observed in healthy persons. Under in vitro conditions, lysosomal enzyme release from the granulocytes decreases in treated individuals and thus a higher lysosomal enzyme activity in the granulocytes is observed. Granulocytes separated from the blood of healthy persons were incubated with Catergen in isotonic and hypotonic media. In an isotonic medium the release did not change significantly. Under the effect of hypotension the release of lysosomal enzyme increased considerably. In vitro incubation with small doses of Catergen significantly inhibited the degree of release. On the basis of these data it may be supposed that Catergen has a stabilizing effect on the lysosomal membrane and is thus beneficial in the treatment of liver injuries (alcoholic, toxic, inflammatory) with lysosomal membrane alterations.

Acid Phosphatase↗

Possible role of a regulatory gene product upon the myo-inositol-1-phosphate synthase production in Neurospora crassa.

The regulatory effect of inositol on inositol-1-phosphate synthase in Neurospora crassa strains was studied. Inositol represses enzyme production in the cultures of the wild type and that of the thermosensitive inositol-requiring mutant grown at 22 degrees C. Enzyme activity as well as the quantity of enzyme protein decreased sharply in both strains by increasing concentrations of inositol in the medium. Inositol-requiring strains used in our experiments can be divided into two groups. The first group produces a protein related immunologically to inositol phosphate synthase, but which is enzymatically inactive. The synthesis of this defective enzyme was also repressed by inositol. In the second group, this protein was found to be completely lacking, in both the thermosensitive mutant grown at 37 degrees C, and in a strain requiring inositol due to a reciprocal translocation. The thermostability and the cross immunoelectrophoresis of the enzyme suggest that in the case of the thermosensitive inositol-requiring mutant, the mutation did not occur in the structural gene of the enzyme, but its regulation was probably affected.

Carbohydrate Epimerases↗

Structure of the Bacillus sphaericus R modification methylase gene.

A 2.5 X 10(3) base-pair segment of Bacillus sphaericus R DNA cloned in Escherichia coli has previously been shown to carry the functional BspRI modification methylase gene. The approximate location of the gene on this DNA segment and its direction of transcription were established by subcloning experiments. The nucleotide sequence of the relevant region was determined by the Maxam-Gilbert procedure. An open reading frame that can code for a 424 amino acid protein was found. The calculated molecular weight (48,264) of this protein is in fair agreement with previous estimates (50,000 to 52,000). The synthesis of this protein was demonstrated in E. coli minicells. The initiation point of transcription by E. coli RNA polymerase was localized by in vitro transcription experiments. The open reading frame starts 29 base-pairs downstream from the transcription initiation site and it is preceded by a sequence showing extensive Shine-Dalgarno complementarity. Subcloning experiments and translation in minicells suggest that after removal of this translational initiation site, a secondary start site 29 amino acids downstream can also start translation in E. coli, and this shorter protein retains the methylase activity. The overall base composition of the gene and the codon usage indicate a strong preference for A.T base-pairs.

Bacillus↗

Identification of two new promoters probably involved in the transcription of a ribosomal RNA gene of Escherichia coli.

The DNA sequence in the region preceding the rrnB gene of Escherichia coli was determined up to the 1821st nucleotide upstream from the beginning of the sequence coding for mature 16 S rRNA. In vitro transcription experiments indicated the presence of two new promoters in this region, located more than 1 kb upstream from the known P1 and P2 promoters of rrnB. Previous electron microscopic studies demonstrated that these sites bind RNA-polymerase very strongly. In vitro transcription, starting at these sites reads through the entire region into the rrnB gene without termination. A similar uninterrupted transcription into rrnB in vivo can be demonstrated by S1-mapping, and by fusing the DNA containing the new promoters (but not P1 and P2) to the lacZ gene. Thus it seems likely that these promoters (P3 and P4) belong functionally to the rrnB gene and play some role in its regulation of expression.

Base Sequence↗

Neuron morphology and synaptic architecture in the medial superior olivary nucleus. Light- and electron microscope studies in the cat.

Dendritic arborization pattern, spatial and synaptic relations of various neuron types and the terminal distribution of afferent axons of various origin were studied in the medial superior olivary nucleus of the cat using Golgi, degeneration, electron microscope and horseradish peroxidase techniques. Three types of neurons clearly different in morphological features, distribution, neighbourhood relations, input and output characteristics were distinguished: (1) fusiform cells having specific dendritic orientations and arborization patterns and synaptic relations to various types of terminal axon arborizations (2) multipolar neurons with wavy dendrites bearing spine-like appendages, receiving relatively few synaptic contacts and having a locally arborizing axon, and (3) elongated marginal cells, largely restricted to the fibrous capsule of the nucleus. The fusiform and marginal neurons were identified by retrograde peroxidase labeling as the olivo-collicular projection cells. Ultrastructural analysis of normal and experimental material revealed the presence of four distinct kinds of axon terminals differing in size, synaptic vesicles type, relation to postsynaptic targets and in origin: (i) large terminals with multiple extended asymmetric synaptic membrane specializations and containing round, clear vesicles arise from the spherical cells of the ipsilateral anteroventral cochlear nucleus, (ii) most of the small axon terminal profiles - engaged in asymmetric synaptic contacts - originated from the trapezoid nucleus, (iii) terminal boutons containing pleomorphic vesicles belong to fibers descending from the ipsilateral multipolar neurons in the central nucleus of the inferior colliculus and from the nuclei of the lateral lemniscus while (iv) boutons containing exclusively ovoid vesicles and remaining intact after complete deafferentation of the nucleus were considered to be of local origin.

Animals↗

Differential diagnostic value of acid phosphatase and beta-glucuronidase in acute leukaemia.

Differential diagnostic importance of acid phosphatase and beta-glucuronidase reactions was studied in bone marrow smears of 52 patients with acute leukaemias. Both reactions showed either diffuse or simultaneously diffuse and granular positivity in the medullary blast cells of 34 patients suffering from ANLL. A strong diffuse positivity of acid phosphatase suggested the possibility of AMOL. Beta-glucuronidase and acid phosphatase reactions were exclusively granular in every positive case of ALL. Increased acid phosphatase activity was found in T-ALL while beta-glucuronidase showed increased activity also in (non-T, non-B)-ALL on several occasions.

Acid Phosphatase↗