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F Georges

Publications and source records attributed to F Georges.

At least 37 records · Page 2Linked to original sources
PubMed1990

Design and cloning of a synthetic gene for the flounder antifreeze protein and its expression in plant cells.

A synthetic gene coding for the winter flounder antifreeze protein (AFP) has been constructed. A new strategy for the synthesis has been employed such that one strand of the duplex was chemically synthesized and the other was produced enzymatically by chain extension. The chemically synthesized blocks were constructed so that the second strand was self-priming. The resulting DNA fragment was incorporated into the vector, pGCS1, which contained a translational fusion of the sequence encoding AFP and the N terminus of cat (encoding chloramphenicol acetyltransferase, CAT), under the control of the cauliflower mosaic virus 35S promoter. This plasmid was introduced into protoplasts of corn (var. Black Mexican Sweet) by electroporation. Production of the fusion peptide was monitored by CAT assay and Western blotting with antisera to AFP and CAT.

Animals↗
PubMed1989

[Tamponade disclosed by functional right-left shunt reversible after surgical drainage].

The authors report a case of tamponade revealed by the discovery, during emergency radioisotope scanning of the lung, of an acquired right-to-left shunt which was reversed by surgical drainage. The patient was a 60-year old woman treated by anticoagulants for suspected pulmonary embolism who had sudden worsening of her symptoms on the 7th day of the disease.

Cardiac Tamponade↗
PubMed1988

Enhancing the sensitivity of DNA detection and recovery from agarose gels.

By inserting nitrocellulose strips into agarose gels alongside the electrophoresed lanes and passing an electric current perpendicularly in the direction of the strips, highly efficient transfer of DNA bands onto the membrane in the form of concentrated dots is achieved. DNA detection limits by this technique are enhanced, at least three times as visualized by ethidium bromide fluorescence and at least twice more by radiolabeling.

Chromatography, High Pressure Liquid↗
PubMed1987

[Is the theoretical blood volume the optimum for chronic respiratory insufficiency? Hemodynamic study of chronic bronchitis patients as a function of the hematocrit].

We have studied oxygen transport and haemodynamics in 19 clinically stable chronic bronchitis split into two groups with comparable blood gases but different haematocrits (Group I = 33%, Group II = 51.5%). The aim of the study was to assess the suitability of bringing the blood volume down to the predicted normal value by repeated venesection. The respiratory function was moderately altered in these patients. The pulmonary and systemic vascular resistance were significantly more elevated in Group II. The arterial oxygen transport was comparable in the two groups. On the other hand for Group I the systolic work of the right ventricle was greater on account of the increased cardiac output. We have not observed any difference in blood volume between the two groups of patients. These results suggest that a return to the predicted blood volume is not recommended without some doubts in chronic bronchitis with polycythaemia.

Blood Pressure↗
PubMed1985

[Exertion isotope tests in coronary insufficiency. Comparison with isotopic ventriculography and myocardial scintigraphy].

Very few studies have been described comparing the value of exercise myocardial scintigraphy and left ventricular angioscintigraphy. The authors designed a study comparing these two investigations with conventional exercise stress testing and coronary angiography. The isotopic investigations were carried out within 48 hours of coronary angiography. A total of 143 patients undergoing coronary angiography (35 normal, 108 coronary patients: 36 single vessel, 36 double vessel and 36 triple vessel disease) were included in this study. The lesions were located of the LAD (77 cases), left circumflex (77 cases) and right coronary arteries (62). The sensitivity and specificity of both radionuclide investigations were evaluated to assess their diagnostic value; the best results were obtained with myocardial scintigraphy (sensitivity 86 p. 100; specificity 100 p. 100); angioscintigraphy had a sensitivity of 71 p. 100 and specificity of 97 p. 100, and conventional exercise stress testing of 42 p. 100 and 70 p. 100 respectively. The sensitivity seemed to increase with the degree of stenosis; although the sensitivity of myocardial scintigraphy increased progressively, that of angioscintigraphy doubled in cases of stenosis 90 p. 100 (stenosis less than 90 p. 100, sensitivity = 37 p. 100; stenosis greater than 90 p. 100, sensitivity = 73 p. 100). The sensitivity of myocardial scintigraphy with respect to the severity of the coronary artery disease was best in cases of right coronary artery stenosis (sensitivity in cases of RCA stenosis = 74 p. 100; sensitivity in LAD stenosis = 58 p. 100; sensitivity in left circumflex stenosis = 43 p. 100). The sensitivity of left ventricular angioscintigraphy was best in LAD stenosis (RCA stenosis = 50 p. 100, LAD stenosis = 64 p. 100, left circumflex stenosis = 36 p. 100). The sensitivity of both investigations was poor in left circumflex artery stenosis even when severely diseased. The sensitivity of both investigations was better in diffuse coronary artery disease: myocardial scintigraphy (single vessel disease: 72 p. 100, double vessel disease: 92 p. 100, triple vessel disease: 94 p. 100), left ventricular angioscintigraphy (61 p. 100, 69 p. 100, and 83 p. 100 respectively). Although the association of these two radioisotopic investigations does not improve diagnostic sensitivity, it does provide more information about the localisation and extension of the coronary artery disease especially in LAD and right coronary artery stenosis. These results suggest that these investigations are complementary in the evaluation of patients with coronary artery disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Disease↗
PubMed1984

A potential stem-loop structure and the sequence CAAUCAA in the transcript are insufficient to signal rho-dependent transcription termination at lambda tR1.

It has been suggested that a sequence in the RNA transcript that can form a stem and loop structure, followed by the sequence CAAUCAA, is the signal for rho-dependent transcription termination. We tested this hypothesis by synthesizing a DNA duplex whose sequence corresponds to a region of the lambda tR1 terminator that contains these structural features. We cloned this synthetic DNA fragment under the control of the lacUV5 promoter, and showed that it does not cause rho-dependent termination in vitro. RNA polymerase pauses during in vitro transcription across the synthetic sequence, although less efficiently than at the corresponding sequence on the lambda template. No rho-mediated termination was detected even under conditions that prolonged transcriptional pausing at the synthetic site, indicating that the synthetic sequence is defective as a transcript release site. We suggest that unlike rho-independent terminators, rho-dependent terminators require sequences in addition to those immediately before the sites of termination.

Base Sequence↗
PubMed1984

Synthesis of a human insulin gene. VII. Synthesis of preproinsulin-like human DNA, its cloning and expression in M13 bacteriophage.

A 74-bp DNA sequence coding for the pre sequence of human preproinsulin and containing EcoRI termini was synthesized by the chemical enzymatic method, joined with previously synthesized proinsulin DNA, and cloned in the M 13mp8 vector. A clone pNB82 -121 was identified by DNA sequence which confirmed the correct orientation of the pre sequence to the proinsulin DNA. The EcoRI site at the junction of pre- and proinsulin DNA was eliminated by removing a triplet ATT using a synthetic 19-mer primer. To simplify preproinsulin isolation and to study its expression in the M 13 system, a 25-bp affinity leader sequence coding for (glu)7 was inserted at the remaining EcoRI site; this put the preproinsulin DNA in a correct reading frame with the AUG initiation codon of beta-galactosidase. Preproinsulin was expressed under lac promoter control as analyzed by a radioimmunoassay (RIA) against C-peptide.

Base Sequence↗
PubMed1984

The human preproinsulin gene: synthesis, cloning, gene modification, and expression studies.

A 355 base pair (bp) DNA sequence coding for human preproinsulin has been assembled by joining a synthetic DNA leader sequence coding for 24 preregion amino acids to the previously synthesized DNA duplex of 277 bp constituting the sequence of BCA chain. It was next cloned in M13 mp8 single-stranded bacteriophage and subjected to site-specific mutagenesis and phase shifting to allow its inducible expression under lac operator control. An affinity leader sequence of 25 bp has been added in an attempt to facilitate purification of the preproinsulin.

Bacteriophages↗
PubMed1977

[Conditions affecting the application of the method of determining blood volume by the injection of labeled (iodine 131) serum albumin to small animals (chick embryo)].

The isotopic dilution method is really suitable for the determination of blood volume in small animals. The main purpose of this study is to find the limits of measuring errors made during the injection procedures (injected volumes about one microliter) and the sampling of blood (blood samples less than one milliliter). After evaluation of the extravascular rate of diffusion of the radioactive iodinated human serum-albumin, the blood volume of the 17 days incubated chick embryo is measured by this method for control purposes.

Animals↗