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Biomedical subjects

F Perrin

Publications and source records attributed to F Perrin.

At least 37 records · Page 2Linked to original sources
PubMed1983

[Comparison of high-frequency jet ventilation and conventional ventilation in the adult respiratory distress syndrome].

Sixteen adult patients with respiratory distress syndrome requiring mechanical respiratory assistance entered this study, the purpose of which was to obtain the same blood gas values under high frequency jet ventilation as under conventional ventilation. When high frequency jet ventilation without spontaneous breathing was compared to continuous positive pressure ventilation, peak airway pressure was the same, but mean airway pressure, positive end-expiratory pressure and pleural pressure were higher and cardiac index lower. When high frequency jet ventilation with spontaneous breathing was compared to intermittent mandatory ventilation, peak airway pressure was lower, mean airway pressure and positive end-expiratory pressure were higher, and pleural pressure and cardiac index were not different.

Adult↗
PubMed1983

Simultaneous variations of PaCO2 and PACO2 in assisted ventilation.

Thirty-two patients receiving artificial ventilation of the lungs were studied to determine if variations in PACO2 could be reflected in variation in PaCO2. Eleven patients had chronic obstructive lung disease, eight had suffered acute respiratory failure, and 13 had neurological disturbances but normal lungs. PaCO2 and PACO2 were measured concurrently as ventilatory patterns, haemodynamic state or inspired gas concentrations changed. Neither change in inspired oxygen concentration nor change in haemodynamic state had much effect PaCO2 or PACO2. Change in PaCO2 induced by ventilatory change and by change in inspired carbon dioxide concentration were well described by linear regression of PaCO2 on PaCO2. In patients with chronic lung disease, (PaCO2-PACO2) was the same at all values of PACO2 whereas, in the other patients the ratio PaCO2/PACO2 did not change.

Adult↗
PubMed1983

Static pressure-volume curves and effect of positive end-expiratory pressure on gas exchange in adult respiratory distress syndrome.

Fifteen patients with adult respiratory distress syndrome (ARDS) were studied: 11 in the early stage of ARDS (group 1); 4 in the late stage (group 2). The inspiratory and expiratory static pressure-volume (P-V) curves of the respiratory system were compared to the pulmonary shunt (Qsp/Qt) when PEEP was increased; cardiac output was kept constant. In group 1 patients, we found that a concavity on the P-V curves was associated with an abrupt decrease in Qsp/Qt when PEEP was increased; the concavity on the expiratory curve was correlated with the change in Qsp/Qt but not the concavity on the inspiratory curve. In group 2 patients, the P-V curves were found rectilinear and Qsp/Qt was not abruptly decreased when PEEP was increased. Expiratory P-V curve can be used to determine: first, whether a patient should be ventilated with PEEP; second, the PEEP level which can be set on the respirator. In group 1 patients, when PEEP was set to a value corresponding to the inflexion point, i.e., the point of departure from the exponential shape (mean value 14.6 +/- 2.8 cm H2O), Qsp/Qt compared to zero PEEP was abruptly decreased to 87.6 +/- 6%; further increase in PEEP had little advantage.

Adolescent↗
PubMed1983

Circannual variations of TSH circadian rhythm parameters in the rat.

We had previously observed a circadian rhythm for serum TSH in male Sprague-Dawley rats (under a 12-hour light-dark cycle, light off at 19.00 h). In the present work the parameters of this previously observed TSH rhythm were determined over a year on a monthly basis. A circadian rhythm was detected for each month except April. From month to month, the amplitudes and acrophases of these rhythms were not significantly different, and a circannual rhythm was only established for the mean TSH concentration over the 24-hour period (mean hormonal value). We conclude that there is a constant circadian pattern for serum TSH fluctuations superimposed on a small basal circannual rhythm of the mean hormonal value.

Animals↗
PubMed1981

The actin gene in yeast Saccharomyces cerevisiae: 5' and 3' end mapping, flanking and putative regulatory sequences.

The 5' and 3' flanking regions of the yeast actin gene have been sequenced and the ends of the actin mRNA were determined by the single-strand nuclease mapping procedure. The mRNA starts with a pyrimidine residue 141 (or 140) nucleotides upstream from the initiation codon. The actin gene lacks a typical "TATA" box 30 base pairs upstream from the mRNA start site but it contains a region homologous to the canonical sequence 5'-GGCTCAATCT-3' which is found in several eukaryotic genes 70 to 80 bp upstream from the mRNA cap site. Judging from the S1 nuclease mapping, there are two populations of actin mRNA terminating 98 and 107 nucleotides downstream from the stop codon. The 3' termini are preceded by three AATAAA sequences found in most eukaryotic polyadenylated mRNAs.

Actins↗
PubMed1981

Cloning of four DNA fragments complementary to human thyroglobulin messenger RNA.

Human thyroglobulin mRNA was isolated from Graves' goitres by size selection of total poly(A)-rich RNA in a sucrose gradient. It sedimented at 33 S, as in other mammalian species, and showed a single component of approximately 8500 bases by gel electrophoresis. cDNA was synthesized from the 33-S RNA by using reverse transcriptase in the presence of human placenta ribonuclease inhibitor and in conditions allowing the formation of long transcripts. The latter was made double-stranded using reverse transcriptase and blunt-ended with nuclease S1. After tailing with dCTP and terminal transferase, the double-stranded cDNA was annealed to pBR322 DNA that had been cleaved at the endonuclease PstI site and tailed with dGTP. The resulting plasmids were used to transform Escherichia coli C600 cells and four cloned recombinants were selected. Each plasmid DNA was shown to contain a sequence complementary to human thyroglobulin mRNA by hybridization with a labeled 33-S mRNA, visualization of cDNA . mRNA hybrids by electron microscopy and filter hybridization selection of mRNA directing the synthesis of immunologically related thyroglobulin peptides in the reticulocyte lysate. The four inserted DNA sequences were 1400 - 1800 base pairs long, two of them showing an homologous sequence of 1100 base pairs. Together, the four cloned DNA fragments represented 63% of the 8500 bases of human thyroglobulin mRNA.

Biotransformation↗
PubMed1981

Quantitation of transcribing native simian virus 40 minichromosomes extracted from CV1 cells late in infection.

Simian virus 40 transcriptional complexes could be extracted from CV1 cells late in infection and separated from the bulk of inactive viral chromatin. Sucrose gradient sedimentation, cesium sulfate equilibrium density gradient centrifugation, and electron microscopy indicated that the viral transcriptional complexes corresponded to at least 0.5 to 1% of the viral minichromosomes extracted, about 5,000 copies per cell.

Cells, Cultured↗
PubMed1980

A detailed comparison of the 5'-end of the ovalbumin gene cloned from chicken oviduct and erythrocyte DNA.

We have examined homologous fragments of DNA cloned from two different tissues for changes in the dNA sequence which might be related to tissue specific gene expression. The 5' end of the chicken ovalbumin gene was cloned from oviduct or erythrocyte DNA DNA using cosmids as vectors. We have compared the two clones obtained by restriction enzyme digestions, analysis of heteroduplexes by electron microscopy or S1 nuclease digestion and by DNA sequencing. Our results show that whereas no alteration occured in the region of the gene assumed to be of importance for the control of transcription, a 4 nucleotide deletion/insertion was detected in the first intron of the ovalbumin gene.

Animals↗
PubMed1980

The ovalbumin gene family: structure of the X gene and evolution of duplicated split genes.

The X, Y and ovalbumin genes, which are found within a 40 kb region of the chicken genome, are all expressed in oviduct under steroid hormone control, and share some sequence homologies. We have now cloned the complete X gene and have analyzed its structure. It codes for two RNA species, X and X'; both are coded by eight exons and appear to differ only by the size of their 3' untranslated region, X' RNA being 1400 nucleotides longer than X RNA. The striking similarity in the number and length of the exons which constitute the X, Y or ovalbumin genes establishes that they have evolved from a common ancestor gene by duplication events. Comparison of selected regions of the X and ovalbumin genes indicates that the exon sequences coding for protein and the location of the splice junctions have been well-conserved. The introns and the 3' untranslated exonic sequences have diverged much more rapidly. Four regions of apparently unrelated repetitive sequences are found both outside the X gene and within it (in two introns and in the sequence coding for the 3' untranslated part of X'RNA). The intragenic repetitive sequences have no counterpart in the ovalbumin and Y genes.

Animals↗