Search PubMed⌕ Search

Biomedical subjects

C Rey

Publications and source records attributed to C Rey.

At least 289 records · Page 16Linked to original sources
PubMed1988

Characterization of granzymes A and B isolated from granules of cloned human cytotoxic T lymphocytes.

A human CD8+ CTL clone with cytolytic potential was shown to express two serine proteases, a 50-kDa homodimer and a 27-kDa monomer, which were purified from cytoplasmic granules. N-terminal sequencing of the purified proteins revealed that the 50-kDa homodimer is the gene product of the human Hanukah factor cDNA clone and that it represents the human homologue to granzyme A. Similarly, the 27-kDa protein was shown to be the serine esterase encoded by the human lymphocyte protease cDNA clone and corresponds to granzyme B. There was no evidence for the presence of other granzymes, in particular for the human homologues to murine granzymes C, D, E, and F. The substrate best cleaved by granzyme A was Gly-Pro-Arg-amido-4-methyl-coumarin after the Arg residue and the pH optimum was 8 to 8.5. Upon triggering of the TCR-CD3 complex with an anti-CD3 mAb, granzyme A was released into the culture medium. Furthermore, a granule-associated hemolytic activity was detected after salt extraction and partial purification of granule proteins. This suggests that hemolytically active human perforin can be obtained from inactive granules.

Amino Acid Sequence↗
PubMed1988

Hepatic transport of bile acids in the isolated perfused rat liver. Structure-kinetic relationship.

We studied the transport kinetics of a series of bile acids from blood to bile in the isolated perfused rat liver in order to define better the relationship between chemical structure of bile acid molecules and efficiency of the overall hepatic transport process. BA studied were taurocholate (TC), glycocholate (GC), cholate (C), tauroursodeoxycholate (TUDC), ursodeoxycholate (UDC) and hyodeoxycholate (HDC). Estimates of intrinsic hepatic clearance (Cl(int)), maximal secretory rate (Vmax) were provided from the analysis of the relationship between bile acid removal rates and sinusoidal concentration under steady-state conditions. TC and TUDC had the highest Cl(int) (about 5 ml/min/g liver) and Vmax (about 800 nmol/min/g liver) followed in order by GC (1.71 ml/min/g liver; 442 nmol/min/g liver); C (1.25 ml/min/g liver; 252 nmol/min/g liver); HDC (0.86 ml/min/g liver; 238 nmol/min/g liver); UDC (0.72 ml/min/g liver; 176 nmol/min/g liver). The findings suggest that the efficiency of the overall hepatic transport of bile acids is highly dependent on their molecular structure and that conjugation has a more important effect on both Cl(int) and Vmax that the number or position of hydroxyl groups.

Animals↗
PubMed1988

cDNA cloning of granzyme C, a granule-associated serine protease of cytolytic T lymphocytes.

A cDNA clone corresponding to the complete amino acid sequence of a putative protease CCP2 of murine cytotoxic T lymphocytes was isolated and sequenced. The clone encodes a 248-residue long serine esterase. The deduced N-terminal amino acid sequence is identical over 40 residues to that of granzyme C, a protease of unknown function present in granules of cytotoxic lymphocytes. Analysis of the sequence of granzyme C/CCP2 reveals high homology to other granzyme proteases, i.e. granzyme A (40%) and granzyme B (67%) and to rat mast cell protease II (46%). The amino acids lining the specificity pocket are well conserved between granzyme B, C, and rat mast cell protease II, but not granzyme A, suggesting a similar general specificity of these three proteases.

Amino Acid Sequence↗
PubMed1988

Effects of ciprofibrate and fenofibrate on liver lipids and lipoprotein synthesis in normo- and hyperlipidemic rats.

The plasma lipoprotein and liver lipid composition, and the lipid, cholesterol and apolipoprotein synthesis have been studied in normal and diet-induced hyperlipidemic rats, receiving ciprofibrate (2.5 mg/kg body weight) or fenofibrate (50 mg/kg b.w.) for 8 days. Ciprofibrate is about 25-fold more active than fenofibrate in reducing plasma triglyceride and cholesterol concentrations both in normolipemic and in hyperlipemic rats. In normolipemic rats ciprofibrate reduced the concentration and the lipid content of all lipoprotein classes. The incorporation of [14C]palmitate and [3H]leucine into the lipoproteins was reduced by ciprofibrate and fenofibrate. The reduction in lipoprotein production was confirmed by prevention of Triton-induced hyperlipemia. Liver and plasma cholesterol synthesis estimated by 3H2O and [14C]mevalonate incorporation indicated an inhibitory effect on HMG-CoA reductase. Administration of ciprofibrate or fenofibrate to rats fed a fat and cholesterol-rich diet partially prevented liver steatosis and hyperlipemia. Both drugs reduced the overproduction of lower density lipoproteins. The ratio of (VLDL + LDL)-cholesterol/HDL-cholesterol which was increased by the diet alone from 0.4 (normal) to 11 remained close to the normal value in the animals receiving ciprofibrate. In the hyperlipemic animals, ciprofibrate reduced the incorporation of [3H]oleate into the liver and plasma glycerolipid and increased cholesterol esterification. Ciprofibrate efficiently reduces plasma levels of cholesterol, triglyceride and phospholipid. Cholesterol and glycerolipid synthesis in the liver were significantly reduced leading to a lower lipoprotein secretion rate in both normolipidemic and diet-induced hyperlipidemic rats.

Animals↗
PubMed1988

Interaction of propranolol with GABA stimulated diazepam binding to rat brain membranes.

1. In the case of an intraperitoneal propranolol injection to rats (25 mg/kg), there was no modification in benzodiazepine and gamma-amino-butyric acid recognition sites since [3H]diazepam or [3H]-muscimol binding was not affected. 2. There was an increase in GABA stimulated-diazepam binding (100%, statistical risk lower than 1%). 3. This last result suggests that propranolol treatment can stimulate GABA-benzodiazepine receptor coupling.

Animals↗
PubMed1988

Percutaneous transluminal balloon valvuloplasty of congenital pulmonary valve stenosis, with a special report on infants and neonates.

Fifty-six percutaneous transluminal balloon valvuloplasty procedures were performed in 51 patients suffering from congenital pulmonary valve stenosis. The patients ranged in age from 1 day to 60 years (mean 6.9 years); 21 were infants less than 1 year of age, including 8 neonates. The peak systolic pressure gradient was greater than 50 mm Hg (mean 81.5) in 47 cases, and less than 50 mm Hg (mean 34.6) in 9. Valvuloplasty enabled a reduction in the mean right ventricular peak systolic pressure from 93.1 to 51.6 mm Hg (p less than 0.001), the mean transvalvular gradient from 73.4 to 27.0 mm Hg (p less than 0.001) and the mean right ventricular pressure expressed as a percent of systemic pressure from 99.5 to 52.0% (p less than 0.001). In infants and neonates, the mean right ventricular pressure expressed as a percent of systemic pressure decreased from 117.3 to 64.4% (p less than 0.001). In 23 patients, follow-up cardiac catheterization at 1 to 17 months revealed a significant change in the right ventricular systolic pressure, which decreased from 54.0 to 46.7 mm Hg (p less than 0.05), and in the peak systolic pressure gradient, which decreased from 27.3 to 22.6 mm Hg (p less than 0.05). Valvuloplasty is an effective procedure in relieving pulmonary stenosis in patients of all ages, including neonates.

Adolescent↗
PubMed1988

Identification and sequencing of cDNA clones encoding the granule-associated serine proteases granzymes D, E, and F of cytolytic T lymphocytes.

Cytoplasmic granules of cytolytic T lymphocytes contain at least six related serine esterases (granzymes) that are released together with perforin, a pore-forming protein related to complement component C9, during target-cell lysis. Polyclonal antibodies were used to isolate a large number of cDNA clones from an expression library derived from cytolytic-T-cell mRNA. Three distinct full-length cDNA clones coding for granzymes D, E, and F were identified by restriction site mapping and nucleotide sequencing. The three deduced amino acid sequences are highly similar to one another (between 72% and 90% amino acid identities) and to the sequences of granzymes B and C, cathepsin G, and rat mast-cell proteases I and II (between 43% and 57% amino acid identities). Cysteine residues capable of forming intramolecular disulfide bonds are conserved, as are the catalytic-site residues characteristic of serine proteases. Comparison of the cDNA-derived protein sequences with the amino termini of the isolated granzymes provides evidence that they are stored in a fully processed, activated form after removal of the signal peptide and two additional residues (propeptide) at the amino terminus. Immunoelectron microscopic studies demonstrated that granzymes D, E, and F are present in the same morphologically distinct cytoplasmic granules in which perforin has been found previously.

Amino Acid Sequence↗
PubMed1988

Unusual evolution of Wilms tumor in a patient with Wiedemann-Beckwith syndrome.

A very unusual case of Wilms tumor in a child with Wiedemann-Beckwith syndrome is presented. The patient had his first metastasis after a disease-free interval longer than three years. Later, he developed spinal epidural involvement. Both data emphasize the oncogenic potential of Wiedemann-Beckwith syndrome in children and support the contention that Wiedemann-Beckwith syndrome worsens the prognosis of Wilms tumor. Patients with Wilms tumor associated to Wiedemann-Beckwith syndrome should receive intensive therapy as well as close and prolonged follow-up in spite of apparent tumor remission.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

[Abnormal origin of the right pulmonary artery from the ascending aorta. Echocardiographic diagnosis apropos of 2 cases].

Anomalous origin of the right pulmonary artery from the ascending aorta is a rare congenital malformation. Formerly identified at angiography and during surgery, it can now be diagnosed by two-dimensional echocardiography, as was done in the two cases reported here. The first case was a neonate in heart failure in whom echocardiography revealed the anomalous origin of the right pulmonary artery; this diagnosis was confirmed at post-mortem examination. The second case was a 4-month old infant in heart failure; echocardiography displayed the malformation which was confirmed at angiography and surgery. In both cases echocardiography showed discontinuity between the pulmonary trunk and the right pulmonary artery and continuity between the pulmonary trunk and the left pulmonary artery. There also was continuity between the right pulmonary artery and the ascending aorta. Doppler ultrasound showed a systolic and a diastolic flow in the right pulmonary artery and only a systolic flow in the left pulmonary artery. A colour-coded doppler examination in one case confirmed the anomalous origin of the right pulmonary artery and the absence of any other abnormality. Two-dimensional echocardiography combined with colour-coded doppler ultrasound therefore is the method of choice to diagnose anomalous origin of the right pulmonary artery from the ascending aorta.

Angiocardiography↗
PubMed1988

[Obstructions to pulmonary ejection and restrictive interventricular septal defects].

The association of a restrictive ventricular septal defect with a pulmonary tract obstruction is rare and may cause diagnostic and therapeutic problems. The authors report their experience of such an association in 10 children. 3 had a tetralogy of Fallot (1 death), 4 a double-outlet right ventricle (2 deaths), and 3 a coarctation of the aorta with ventricular septal defect and pulmonary artery banding (no death). Prognosis depends on the type of malformation. It has improved with years because of sooner recognition of these malformations and better surgical technics and post-operative care.

Adolescent↗
PubMed1988

Differential response of normal and cirrhotic liver to vasoactive agents. A study in the isolated perfused rat liver.

In cirrhosis, endogenous vasoactive agents could act as modulators of intrahepatic resistance and thus portal pressure. The aim of this work was to study the effects of norepinephrine, angiotensin II and arg8-vasopressin on intrahepatic portal resistance in isolated perfused livers from normal rats and rats with carbon tetrachloride-induced cirrhosis. Livers were perfused at a constant pressure and the measured variable was portal blood flow. Dose-response curves were obtained by cumulative addition of agonists to the perfusate. The three vasoactive agents increased resistance in normal and cirrhotic livers. The maximal amplitude of response was similar in normal and cirrhotic livers. The cirrhotic livers exhibited an increased sensitivity to norepinephrine, a decreased sensitivity to angiotensin II but an unchanged sensitivity to arg8-vasopressin. The shape of the dose-response curve for norepinephrine and arg8-vasopressin, but not for angiotensin II, was modified in cirrhotic livers. We conclude that the cirrhotic liver retains a strong vascular reactivity to vasoactive agents and particularly to norepinephrine.

Algorithms↗
PubMed1987

Comparison of basal and noradrenaline stimulated methylation of chloroform-extractable products in synaptosomal preparations from the rat brain.

Noradrenaline addition increases (S-adenosyl-L-methionine)-methylation of chloroform extractable products in the rat brain synaptosomal preparation. The characteristics of this methylation (MgCl2 dependence, S-adenosyl-L-methionine concentration dependence) are different from those of phosphatidylethanolamine methylase. The greatest increase was induced by noradrenaline in the 10(-4) M concentration range; preincubation of noradrenaline with the membranes, before S-adenosyl-L-methionine addition, was necessary. The TLC analysis of chloroform extractable products showed that: methylation of phosphatidylethanolamine derivatives was increased and the production of another unknown product (corresponding to that described by Wazer et al., Life Sci. 32, 2535, 1983) was more enhanced.

Animals↗