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Biomedical subjects

R Nagy

Publications and source records attributed to R Nagy.

At least 19 recordsLinked to original sources

Biological and molecular characterisation of potential biocontrol strains of Trichoderma.

Thirty-four strains of seven species of Trichoderma isolated from various fungal sources were compared for direct mycoparasitic activity (MPA), chitinase production and antibiotic activity (ANA) in order to choose the most appropriate partners for a strain-breeding programme. Within species genetic differences were also assesses in T. hamatum, T. harzianum and T. viride by means of random amplification of polymorphic DNA (RAPD). Endochitinase activities of the Trichoderma strains ranged between 20.4 and 1264.5 units/g dry weight of mycelium. The correlation between MPA and chitinase activity was not unambiguous and no correlation existed between MPA and ANA. The RAPD patterns of T. viride strains were highly variable, while isolates of T. harzianum proved to be more uniform; T. hamatum revealed remarkable intraspecific divergence. All these three comprised certain pairs of strains that are promising participants of a strain-improving programme, since their strong genetic affinities offer good changes for combining their contrasted biocontrol traits.

Chitinases

Mini-chromosomes in Fusarium sporotrichioides are mosaics of dispersed repeats and unique sequences.

Variations in trichothecene patterns of 26 Fusarium sporotrichioides isolates from different plant and geographic origins showed no correlation with electrophoretic karyotype polymorphisms. When intact chromosomes were examined, interisolate karyotype differences were observed only in the mini-chromosome range. Further polymorphisms were revealed in Notl-digested samples. By summing the Notl fragments the average genome size of F. sporotrichioides was estimated to be 20.4 Mb. Mini-chromosomes shared common sequences with the larger ones; however, clones (RMS-1 and RMS-2) specific to these structures have also been found. These clones contained no coding region and no promising similarities were observed when they were compared to sequences held at GenBank. Mini-chromosomes in F. sporotrichioides constitute a mosaic composed of dispersed repeats and unique sequences. This mosaic structure was maintained in all noninterbreeding, genetically isolated strains examined.

Chromosomes, Fungal

Derivation of completely cell culture-derived mice from early-passage embryonic stem cells.

Several newly generated mouse embryonic stem (ES) cell lines were tested for their ability to produce completely ES cell-derived mice at early passage numbers by ES cell <==> tetraploid embryo aggregation. One line, designated R1, produced live offspring which were completely ES cell-derived as judged by isoenzyme analysis and coat color. These cell culture-derived animals were normal, viable, and fertile. However, prolonged in vitro culture negatively affected this initial totipotency of R1, and after passage 14, ES cell-derived newborns died at birth. However, one of the five subclones (R1-S3) derived from single cells at passage 12 retained the original totipotency and gave rise to viable, completely ES cell-derived animals. The total in vitro culture time of the sublines at the time of testing was equivalent to passage 24 of the original line. Fully potent early passage R1 cells and the R1-S3 subclone should be very useful not only for ES cell-based genetic manipulations but also in defining optimal in vitro culture conditions for retaining the initial totipotency of ES cells.

Animals

Electrophoretic karyotypes and gene mapping in eight species of the Fusarium sections Arthrosporiella and Sporotrichiella.

Pulsed-field gel electrophoresis was used to identify karyotypes for eight species of the Fusarium sections Arthrosporiella and Sporotrichiella. The total number of chromosome-sized DNA molecules varied from six to nine, depending on the species. The sizes of chromosomes ranged from 0.4 to approximately 6.5 Mb which gave estimates of genome size of between 27.0 and 29.9 Mb. When fractionated chromosomes of the eight species were probed with Tox5, a gene coding for the key-enzyme of trichothecene biosynthesis, strong hybridization signals developed in F. poae and F. sporotrichioides, suggesting that of the eight species examined only these two have the genetic potentiality to produce trichothecene mycotoxins. By using heterologous probes from Aspergillus different rRNA loci have also been mapped on Fusarium chromosomes.

Chromosome Mapping

[Idiopathic thrombocytopenia caused by varicella].

The authors deal with the case of a 6-year old girl in whom thrombocytopenia developed with haemorrhagic symptoms as a rare complication of varicella. They give a short review about the reasons and the etiology of idiopathic thrombocytopenic purpura, and deal with the mechanism of thrombocytopenia caused by varicella.

Chickenpox

The amobarbital interview in a general hospital setting, friend or foe: a case report.

The amobarbital interview has been in use for over 50 years. Its clinical indications have been primarily as an aid in determining a diagnosis and in conducting psychotherapy. This article presents an overview of the procedure along with a brief historic perspective. A case is presented which highlights its potential clinical utility and shortcomings.

Adult

Mouse DNA polymerase alpha-primase terminates and reinitiates DNA synthesis 2-14 nucleotides upstream of C2A1-2(C2-3/T2) sequences on a minute virus of mice DNA template.

The distribution of termination and initiation sites in a 5081-nucleotide minute virus of mice DNA template being copied by a highly purified mouse DNA polymerase alpha-DNA primase complex in the presence of GTP has been examined. The 3'-hydroxyl termini (17 in all) were clustered at six sites that were located 2-14 nucleotides upstream of C2A2C2, C2AC3, or C2A2T2 sequences. When either [alpha-32P]- or [gamma-32P]GTP was included in the DNA polymerase reaction mixtures, nascent DNA became radiolabeled. Analysis of the 32P-labeled material following treatment of the DNA with tobacco acid pyrophosphatase, bacterial alkaline phosphatase, or ribonuclease T1 revealed the presence of oligoribonucleotide chains averaging 5-7 nucleotides long and beginning with 5' GTP residues. Eight presumptive DNA primase initiation sites were located opposite C4 or C5 sequences 3-9 nucleotides upstream of one of the three closely related hexanucleotides C2A2C2, C2AC3, and C2A2T2. RNA-DNA junctions were found 3-10 nucleotides downstream of DNA primase initiation sites. The results indicate that hexanucleotides having the general formula C2A1-2(C2-3/T2), herein referred to as psi, are involved in promoting termination of DNA synthesis and/or de novo initiation of RNA-primed DNA chains by DNA polymerase alpha-primase.

Animals

ATP(GTP)-dependent conversion of MVM parvovirus single-stranded DNA to its replicative form by a purified 10 S species of mouse DNA polymerase alpha.

A species of DNA polymerase alpha that is active in the ATP(GTP)-dependent conversion of MVM parvovirus single-stranded linear DNA to the duplex replicative form has been purified 4300-fold from Ehrlich ascites mouse tumour cells. The single-stranded----replicative form activity is maintained throughout ammonium sulfate precipitation, DEAE-cellulose, phosphocellulose and hydroxyapatite column chromatography and glycerol gradient sedimentation. Polypeptides with Mr = 230 000, 220 000, 183 000, 157 000, 125 000, 70 000, 65 000, 62 000, 57 000, 53 000 and 48 000 copurify with the single-stranded----replicative form activity, which sediments at approx. 10 S. The Mr = 183 000, 157 000 and 125 000 polypeptides exhibit catalytic activity when assayed in situ following SDS-polyacrylamide gel electrophoresis. The 10 S form of DNA polymerase alpha is functionally distinguishable from an 8.4 S form of the enzyme obtained from the same cells on the basis of single-stranded----replicative form activity. The single-stranded----replicative form activity of the 10 S enzyme is stable at 22 degrees C for up to 3 h, but exhibits a half life of only 5 min at 45 degrees C.

Adenosine Triphosphate

Microcomputer applications in retinal research.

A low cost microcomputer was used to: (1) word process and edit this manuscript, (2) create a patient file storage and retrieval system, (3) transcribe and store information from video display such as wide-angle fundus photographs and fluorescein angiograms, (4) plot data points in graphic display mode, (5) solve complex equations used to calculate intraocular tumor volumes, (6) search medical literature data bases, and (7) directly interface with sophisticated laboratory equipment performing complicated tasks such as multicomponent analysis and enzyme kinetics.

Computers

Cutaneous manifestations of acute carbon monoxide poisoning.

A patient with acute carbon monoxide poisoning due to leakage of gas from the exhaust system in his automobile noted edema and blister formation over large areas of the skin of one half of his body. Rhabdomyolysis, acute but transient renal insufficiency, and hemolytic anemia developed subsequently.

Acute Kidney Injury

Hereditary sclerosing poikiloderma.

Three persons with hereditary sclerosing poikiloderma were studied to find any clue to explain the mechanism involved in producing the cutaneous lesions which are so striking clinically and also evident histologically. Investigational studies included a blood chemistry screen, chromosome analyses, and skin biopsies evaluated by routine stains as well as by electron microscopy and direct immunofluorescence. No mechanism for the production of the clinical and histological changes in the dominantly inherited disorder was found.

Adolescent