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Biomedical subjects

F Perrin

Publications and source records attributed to F Perrin.

At least 55 records · Page 3Linked to original sources
PubMed1980

Isolation and characterization of the mouse metallothionein-I gene.

Double-stranded cDNA was synthesized from a mouse liver mRNA fraction enriched for metallothionein mRNA activity, ligated to restriction site linkers, inserted into pBR322, and used to transform Escherichia coli chi 1776. The sequence of the largest plasmid containing DNA that hybridized to metallothionein mRNA was determined and shown to contain a 380-base-pair insert that includes the entire coding region and 3' untranslated region of metallothionein-I. The metallothionein-I insert was nick-translated and used to screen both a mouse myeloma and a mouse embryo DNA library in bacteriophage lambda. A metallothionein-I genomic clone containing 13-15 kilobase pairs of mouse DNA was isolated from each library. Both contain a 3.8-kilobase-pair EcoRI fragment that hybridizes to the metallothionein-I probe. The location, size, and orientation of the metallothionein-I gene within the 3.8-kilobase-pair fragment were determined by heteroduplex and restriction mapping. The gene spans 1.1 kilobase pairs and contains at least two introns.

Animals↗
PubMed1980

Evidence for circadian variations in serum thyrotropin, 3,5,3'-triiodothyronine, and thyroxine in the rat.

We previously observed that under a 12-h light, 12-h dark schedule (lights off at 1900 h), male Sprague-Dawley rats showed a circadian rhythm for serum TSH with a zenith near midday. In the present work we further characterized the serum TSH rhythm by appropriate mathematical analysis. The peak of serum TSH occurred at 1130 +/- 0105 h (mean of five experiments), with an amplitude of 0.2 +/- 0.1 microgram/ml, while the TSH level was minimum at the beginning of the dark period; the period of the TSH rhythm was 24.5 +/- 0.6 h. A circadian rhythm was also demonstrated for serum T3 and T4; these rhythms were characterized by peaks occurring 1.5 and 2.2 h after that of TSH, respectively. As expected, characteristics of the rhythm were more narrowly defined for T3 than for T4. Serum concentrations peaked at 1256 +/- 0206 and 1346 +/- 0308 h for T3 and T4, respectively; the serum T3 concentration varied from 78.7 +/- 7.8 to 54.2 +/- 2.7 ng/100 ml (P < 0.001) and serum T4 varied from 7.3 +/- 1.1 to 5.1 +/- 0.5 microgram/100 ml (P < 0.05) for zenith and nadir values, respectively. It is suggested that the diurnal peaks of thyroid hormones might be related to TSH-induced changes in thyroid secretion.

Animals↗
PubMed1979

Organization and sequence studies of the 17-piece chicken conalbumin gene.

The conalbumin gene has been cloned and shown to consist of at least 17 exons approximately 60-200 base pairs long. The DNA sequence upstream from the region coding for the 5' end of the mRNA shows similarities with sequences present in homologous positions in other genes. High and low frequency repetitive sequences are found both upstream from the conalbumin gene and within one intron.

Animals↗
PubMed1979

Isolation of the lysozyme gene of chicken.

The lysozyme gene has been purified by molecular cloning from two chicken gene libraries. Several recombinant phages harbouring sequences homologous to a plasmid carrying a double stranded lysozyme cDNA have been isolated. One recombinant appears to carry an entire lysozyme gene. Electron microscopic studies show that the latter is split by at least three introns. The length of the gene is about 3.9 kb, 6 times longer than lysozyme mRNA.

Animals↗
PubMed1979

The chicken conalbumin gene: studies of the organization of cloned DNAs.

The construction of a double-stranded conalbumin cDNA plasmid (1) has allowed us to investigate the structure of the conalbumin gene. Restriction enzyme mapping of chicken genomic DNA reveals that the conalbumin gene is split and is contained in three EcoRI fragments "a", "b", "b" and "c" which have sizes of 10.7, 4 and 2.5 kb, respectively. Analysis with specific probes shows that the orientation of these fragments with respect to transcription is 5'-"b", "c" and "a"-3. The fragments Eco "b", Eco "c" and part of Eco "a" have been isolated by molecular cloning from three different "libraries". Electron microscopic studies of hybrids between cloned DNA's and conalbumin mRNA show that one of the isolated clones, lambda C4-conl, contains the coding sequences for the first 940 nucleotides of the mRNA (out of 2400). This region is highly split, since it contains seven short exonic sequences separated by six intervening sequences. The DNA region coding for these 940 nucleotides is 5 times longer than the mRNA coding sequences, a ratio very similar to that found for other chicken genes.

Animals↗
PubMed1979

Cloning of an almost full-length chicken conalbumin double-stranded cDNA.

Chicken conalbumin double-stranded cDNA (con-dscDNA) was synthesized from a laying hen oviduct mRNA preparation enriched for conalbumin mRNA (con-mRNA). The dscDNA was inserted by blunt-end ligation into the Sal I site of plasmid pBR322 which had been repaired with DNA polymerase I to create Taq I sites on each side of the inserted fragment. After bacterial transformation, one hybrid recombinant, pBR322-con1, which contains the largest inserted dscDNA (about 2350 bp) was shown to hybridize specifically to the RNA which is translated into conalbumin. Electron microscopic examination of hybrid molecules between con-mRNA and pBR322-con1 DNA indicate that the inserted con-dscDNA is an almost full-length double-stranded transcript of conalbumin mRNA.

Animals↗
PubMed1979

The ovalbumin gene region: common features in the organisation of three genes expressed in chicken oviduct under hormonal control.

Two large DNA fragments overlapping the chicken ovalbumin gene have been isolated by molecular cloning. Analysis of these fragments provided a map of a 46,000-base pair region of the chicken genome. This region contains the complete ovalbumin gene (including its mRNA leader-coding sequence) and at least two other genes of unknown function. All three genes are orientated in the same direction and their expression in chicken oviduct is under hormonal control. The three genes share some sequence homologies, suggesting that duplications have occurred in the ovalbumin gene region in the course of evolution.

Animals↗
PubMed1979

Organisation and sequences at the 5' end of a cloned complete ovalbumin gene.

A clone which contains the complete chicken ovalbumin gene, including its leader coding sequences, has been isolated. From electron microscopic analysis of this DNA we conclude that the minimal size of the transcriptional unit for ovalbumin is 7.7 kilobases. The DNA sequence of the region surrounding the 5' end of the ovalbumin gene is presented. Comparison of this sequence with those of other eukaryotic genes reveals striking similarities, possibly related to a promoter region, approximately 30 base pairs upstream from the site coding for the 5' end of the mRNA.

Animals↗
PubMed1978

Yeast temperature-sensitive mutants specifically impaired in processing of poly(A)-containing RNAs.

The selection at 22 degrees C of yeast cordycepin (3'-deoxyadenosine) sensitive mutants which would be temperature-sensitive at 37 degrees C allowed the obtention of mutants specifically impaired in processing of Poly(A)-containing RNAs at 37 degrees C. The mutants displaying this phenotype belong to two different loci. The biochemical study of the physiological function which is blocked by the mutation has revealed that the level of radioactive Poly(A)-containing RNAs found in a 5 min pulse after a 10 min shift at 37 degrees C is 6 times less in the mutants than in the wild type without reduction of the non Poly(A)-containing RNAs fraction. Further studies have shown no alteration in the two Poly(A) polymerases activities and suggest strongly a faster decay of Poly(A)-containing RNAs in the mutants.

DNA-Directed RNA Polymerases↗
PubMed1978

Isolation by molecular cloning of a fragment in the split ovalbumin gene.

An EcoRI fragment of chicken DNA (fragment 'a') containing a sequence complementary to the 3' half of ovalbumin mRNA has been isolated by molecular cloning. Analysis of the cloned fragment proves conclusively that the chicken ovalbumin gene is split. Fragment 'a' contains no extensive sequence repeated elsewhere in the genome and represents the only type of organisation of this part of the split ovalbumin gene in chicken genome.

Animals↗
PubMed1978

[Respiratory function tests during artificial ventilation. Application in the choice of apparatus settings (author's transl)].

Twenty seven patients on artificial ventilation were studied in terms of gas exchange, respiratory mechanics and haemodynamics. The characteristics of acute respiratory failure (dead space effect, shunt effect, disturbances in respiratory mechanics) may be identified and their severity determined. The effects of adjusting artificial ventilation settings (tidal volume, frequency, inspiration/expiration ratio, inspiratory flow, end expiratory pressure, inspired oxygen fraction) may be studied and better adapted to the individual functional requirements of each patient. An organigram of settings based upon the experience gained in this series is suggested.

Asthma↗
PubMed1978

Electron microscopy and restriction enzyme mapping reveal additional intervening sequences in the chicken ovalbumin split gene.

The Eco RI fragment "b" of chicken DNA (Breathnach, Mandel and Chambon, 1977), which contains the sequences coding for the 5' quarter of ovalbumin mRNA (ov mRNA), has been isolated by molecular cloning using a "shotgun" approach. Electron microscopy and restriction enzyme analysis have revealed that the sequences coding for the 5' quarter (approximately 500 nucleotides) of ov mRNA are split into four regions separated by three intervening sequences. The cloning procedure seems to be reliable, since the restriction enzyme pattern of the cloned Econ RI fragment "b" is similar to that of the corresponding chromosomal DNA fragment. There is no evidence supporting the existence of a 150-200 nucleotide long sequence at the 5' end of the ov mRNA similar to the "leader" sequences found at the 5' end of some adenovirus and SV40 mRNAs.

Animals↗
PubMed1978

The ovalbumin split gene: molecular cloning of Eco RI fragments "c" and "d".

The Eco RI fragments "c" and "d" of the ovalbumin gene (1, 2) have been isolated by molecular cloning. Restriction enzyme mapping and electron microscopy have confirmed that the two fragments contain the same ovalbumin mRNA coding sequences. These sequences are split into two regions which have been mapped in fragments "c" and "d". There is no evidence that the ovalbumin mRNA sequences contained in these fragments could be further interrupted. Our results confirm that the presence of Eco RI fragment "d" in some chickens is due to the existence of an allelic variant of the ovalbumin gene which contains an additional Eco RI site within the region corresponding to Eco RI fragment "c". This additional Eco RI site appears to be the main difference between the two alleles. Finally, our results provide a direct demonstration that most of the ovalbumin mRNA sequences are encoded for by Eco RI fragments "a", "b" and "c".

Coliphages↗
PubMed1978

Structural analysis of viral replicative intermediates isolated from adenovirus type 2-infected HeLa cell nuclei.

Deoxyribonucleoprotein complexes released 17 h postinfection from adenovirus type 1 (Ad2)-infected HeLa cell nuclei were shown by electron microscopy to contain filaments much thicker (about 200 A [20 nm]) than double-stranded DNA (about 20 A [2 nm]). The complexes were partially purified through a linear sucrose gradient, concentrated, and further purified in a metrizamide gradient. The major protein present in the complexes was identified as the 72,000-dalton (72K), adenovirus-coded single-stranded DNA-binding protein (72K DBP). Three types of complexes have been visualized by electron microscopy. Some linear complexes were uniformly thick, and their length corresponded roughly to that of the adenovirus genome. Other linear genome-length complexes appeared to consist of a thick filament connected to a thinner filament with the diameter of double-stranded DNA. Forked complexes consisting of one thick filament connected to a genome-length, thinner double-stranded DNA filament were also visualized. Both thick and thin filaments were sensitive to DNase and not to RNase, but only the thick filaments were digested by the single-strand-specific Neurospora crassa nuclease, indicating that they correspond to a complex of 72K DBP and Ad2 single-stranded DNA. Experiments with anti-72K DBP immunoglobulins indicated that these nucleoprotein complexes, containing the 72K DBP, correspond to replicative intermediates. Both strands of the Ad2 genome were found associated to the 72K DBP. Altogether, our results establish the in vivo association of the 72K DBP with adenovirus single-stranded DNA, as previously suggested from in vitro studies, and support a strand displacement mechanism for Ad2 DNA replication, in which both strands can be displaced. In addition, our results indicate that, late in infection, histones are not bound to adenovirus DNA in the form of a nucleosomal chromatine-like structure.

Adenoviruses, Human↗
PubMed1977

Adenosine 3'5'-cyclic monophosphate dependent protein kinase in human adrenocortical tumors.

Protein kinase activity has been studied in four human adrenocortical tumors and compared to the one of the normal human adrenal. In two cases where the lack of action of ACTH was related to an anomaly of ACTH receptor, the protein kinase activity was normal. In the other two cases the ACTH receptor was normal, but the protein kinase activity was different from that of the normal adrenal. In one of these cases where the steroidogenesis response of isolated tumor cells to ACTH and DcAMP was higher than in normal adrenal, basal and cAMP stimulated protein kinase activities were significantly higher than those of the normal adrenal, but the activation constants of both nucleotides were similar to those of the normal gland. In the other case, the basal and the cAMP stimulated protein kinase activities were significantly lower, as well as the activation constant of cAMP. However, the binding affinity of 3H-cAMP was normal. Normal adrenal cytosol contains three protein kinases, as resolved by DEAE-cellulose, two of which designated I and II, are cAMP-dependent. The DEAE-cellulose chromatography of the last tumor showed a loss of isoenzyme II. In addition, the protein kinase eluted at the same molarity as that of isoenzyme I of the normal adrenal was not activated by cAMP. Therefore, the lack of response to ACTH of some adrenocortical human tumors may be attributed either to an anomaly of the ACTH receptor or to some defect of the cAMP-dependent protein kinase.

Adrenal Cortex Neoplasms↗