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Biomedical subjects

F Rey

Publications and source records attributed to F Rey.

At least 127 records · Page 7Linked to original sources
PubMed1985

Atypical phenylketonuria with "dihydrobiopterin synthetase" deficiency: absence of phosphate-eliminating enzyme activity demonstrated in liver.

An assay for the phosphate-eliminating enzyme (PEE) activity in liver was developed which required only 5-10 mg tissue. PEE catalyses the elimination of inorganic triphosphate from dihydroneopterin triphosphate, which is the second and irreversible step in the biosynthesis of tetrahydrobiopterin (BH4). In the presence of substrate, magnesium, NADPH, and a sepiapterin reductase fraction from human liver, PEE catalysed the formation of BH4 which was measured by HPLC and electrochemical detection. In adult human liver, a PEE activity of 1.02 +/- 0.134 microU/mg protein (mean +/- 1 SD; n = 5) was observed. In liver needle biopsy material from five patients with defective biopterin biosynthesis, no PEE activity was found (less than 2% and 6% of the control values, respectively). The presence of an endogenous inhibitor was excluded. In a patient who died without definite diagnosis and in a patient with beta-thalassaemia liver PEE activity was increased. Sepiapterin reductase activity was present in all cases. Results indicate that in "dihydrobiopterin synthetase" deficiency, the most frequent of the rare BH4-deficient variants of hyperphenylalaninaemia, the molecular defect consists in a defect of PEE.

Adult↗
PubMed1985

Evidence for pancreas injury in adult respiratory distress syndrome.

The purpose of this study was to investigate the relation between serum lipase (LP), serum immunoreactive trypsin (IRT), and its inhibitors in patients with adult respiratory distress syndrome (ARDS) of diverse origin and to compare their time course with other acute conditions. The IRT and LP levels were determined at regular intervals in 41 patients hospitalized in the intensive respiratory unit with ARDS (n = 9), acute pancreatitis (n = 5), shock (n = 9), bronchopneumonia (n = 10), or acute cardiogenic pulmonary edema (n = 8). Several trypsin inhibitors were measured simultaneously: serum trypsin inhibitory capacity (TIC), alpha 1-antitrypsin, alpha 2-macroglobulin, and antithrombin III. Concomitantly, angiotensin-converting enzyme (ACE) activity was determined as a potential marker of the endothelial injury. A respective 19- and 13-fold increase in IRT and LP values were observed in patients with ARDS after a mean evolution of 6 days; similar increases were seen in patients with pancreatitis. These values were significantly higher than those observed in the other conditions studied. In patients with ARDS and acute pancreatitis, the evolution of IRT and LP values were associated with a sixfold rise in TIC. A low TIC/IRT ratio in patients with ARDS appeared to be an index of poor prognosis. Conversely, ACE activity evolution was characterized by an early decrease in all the conditions studied. These observations indicate that there is an acute delayed pancreas injury in ARDS. Thus, the release of pancreatic enzymes are not reliable markers of the early evolution of the disease but they may represent secondary mediators for enhancement of the increased endothelial permeability.

Adult↗
PubMed1985

[Yield of the thoracoscopic biopsy in experimental pulmonary infections in the immunosuppressed rabbit].

Using thoracoscopy lung biopsy we investigated the bacteriological diagnostic yield in immunodepressed and/or infected NZ rabbits. 84 rabbits were used: 18 controls, 30 immunodepressed rabbits and 36 rabbits immunodepressed and then infected with Aspergillus fumigatus. Candida albicans or B.C.G. The thoracoscopy technique was the one we designed for humans, the instruments were adapted to the size of animals. Thoracoscopy biopsy results were compared to those of surgical biopsies made in the same animals. The results of both techniques were similar: indeed, the sensitivity of thoracoscopy biopsy was 88.9% in immunodepressed rabbits (versus 100% with surgical biopsies), 86% in the group of rabbits infected with B.C.G. (versus 86%), 90.1% in rabbits infected with Aspergillus fumigatus (versus 100%) and 88.9% in rabbits infected with Candida albicans (versus 100%). The indications for thoracoscopic lung biopsy in immunodepressed patients with infectious lung diseases are drawn from these experimental data, from our experience and the known mortality and morbidity of surgical lung biopsy.

Animals↗
PubMed1984

Induction of cellular DNA polymerases in a Burkitt lymphoma-derived cell line by treatment with 5-iododeoxyuridine.

Cellular DNA polymerases of a Burkitt lymphoma-derived cell line (P3HR-1) were found to be greatly induced by treatment of the cells with 5-iododeoxyuridine (IUdR) at a concentration which induces Epstein-Barr virus (EBV) early antigen (EA) expression. The activities of all the DNA Polymerases alpha, beta and gamma in P3HR-1 cells increased 7-9 fold by exposure of the cells to IUdR (25 micrograms/ml) for 3 days, while the EBV-coded DNA polymerase activity in the cell remained undetectable under the assay conditions employed. Under the same culture conditions with IUdR, EA-positive P3HR-1 cells increased to 16.6% which was much higher than that of the non-treated control cells (0.32%). On the other hand, another Burkitt lymphoma cell line, Raji, had very low incidence (1.27%) of EA induction by IUdR-treatment and the level of DNA polymerase activities remained almost unchanged. From these results it seems that the increase in DNA polymerase activity during the treatment of P3HR-1 cells with IUdR is closely related to high incidence of EA expression in these Burkitt lymphoma cells. Also, the finding has revealed yet unknown effect of IUdR on cultured cells and provides a useful tool to obtain a large quantity of the induced cellular DNA polymerases from the P3HR-1 and KB cells.

Burkitt Lymphoma↗
PubMed1984

Isolation of human T-lymphotropic retrovirus (LAV) from Zairian married couple, one with AIDS, one with prodromes.

A Zairian married couple had been living in France since 1981. The man had acquired immunodeficiency syndrome (AIDS) and his wife had prodromes of the disorder. Infection with a human T-lymphotropic retrovirus (lymphadenopathy-associated virus) was demonstrated in both by isolation of the virus from their cultured lymphocytes and the detection of specific antibodies in serum samples. Since this virus has been isolated from patients in other AIDS risk categories, the finding of the virus in AIDS patients from the African group adds further support to the hypothesis that this human retrovirus is the AIDS aetiological agent.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Hudson memorial lecture. Neonatal management of organic acidurias. Clinical update.

Therapeutic guidelines have been obtained from a retrospective review of 41 patients affected with organic acidaemias, 16 patients with neonatal maple syrup urine disease (MSUD), 11 methylmalonic acidaemia, (MMA) seven propionic acidaemias (PA) and seven isovaleric acidaemias (IVA), and by comparing this personal series with similar reported cases. The emergency treatment of these organic acidurias in the neonate has to main goals: toxin removal and anabolism. Anabolism is always promoted by early diet therapy. The best method of toxin removal depends on the nature of the defect; peritoneal dialysis with exchange transfusions or multiple or prolonged exchange transfusions in MSUD and in PA, diuresis and exchange transfusions in MMA and glycine supplementation in IVA. Vitamin supplementation (thiamine 20 mg, biotin 10 mg, B12 2 mg and riboflavin 100 mg) should be tried in all cases although the neonatal forms of these defects are very rarely vitamin responsive. Additional treatments such as carnitine or insulin may prove to be useful.

Acids↗
PubMed1984

Monitoring of serum levels of imipramine and desipramine and individualization of dose in enuretic children.

The serum levels of imipramine (IMI) and its active metabolite desipramine (DMI) were monitored in 90 children with primary nocturnal enuresis. Ages ranged between 5 and 14 years. Serum concentrations were determined in 21 children at 24 h after administration of a dose of 75 mg and once when steady state had been reached, 12 h after the last dose; a good correlation was seen between the total levels (IMI + DMI) on those two occasions (r = 0.81; p less than 0.01). This serves as a basis to predict the steady-state levels of IMI + DMI reached in an individual patient. In the remaining patients the serum levels of IMI + DMI were determined at steady state. Dosage regimens were adjusted individually to obtain a favorable response with regard to the frequency of enuresis and to the possible occurrence of side effects. Good correlation was established between the serum concentrations of IMI + DMI at steady state and the frequency of enuresis, with a favorable response being obtained for levels greater than 80 ng/ml. Monitoring of serum levels leads to better compliance with the regimen throughout treatment.

Adolescent↗
PubMed1984

Evidence for the presence of a neutral insulinotrophic peptide in the porcine duodenum.

A crude mixture of thermostable peptides extracted from porcine duodenum was fractionated by electrofocusing. A neutral fraction, different from the basic fractions of GIP, VIP, PHI, and CCK was found to promote insulin secretion when injected in vivo to normal rats. This neutral fraction, extracted from the crude mixture by chromatography, stimulated insulin output from an isolated rat pancreas and enhanced glucose-induced insulin release. The insulinotrophic effect of this partially purified duodeno-jejunal material disappeared following digestion with trypsin. The insulin-releasing activity was found to correspond to a compound of molecular weight higher than that of insulin (i.e. higher than 6000). No GIP-like immunoreactivity was found in this neutral fraction indicating that the active peptide(s) are not GIP related compounds. These observations suggest that porcine duodenum contains and incretin activity different from that of the insulinotrophic factors already reported.

Animals↗
PubMed1983

Isolation of a T-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS).

A retrovirus belonging to the family of recently discovered human T-cell leukemia viruses (HTLV), but clearly distinct from each previous isolate, has been isolated from a Caucasian patient with signs and symptoms that often precede the acquired immune deficiency syndrome (AIDS). This virus is a typical type-C RNA tumor virus, buds from the cell membrane, prefers magnesium for reverse transcriptase activity, and has an internal antigen (p25) similar to HTLV p24. Antibodies from serum of this patient react with proteins from viruses of the HTLV-I subgroup, but type-specific antisera to HTLV-I do not precipitate proteins of the new isolate. The virus from this patient has been transmitted into cord blood lymphocytes, and the virus produced by these cells is similar to the original isolate. From these studies it is concluded that this virus as well as the previous HTLV isolates belong to a general family of T-lymphotropic retroviruses that are horizontally transmitted in humans and may be involved in several pathological syndromes, including AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Clinical usefulness and methodology of immunological assay of pancreatic enzymes.

Radioimmunoassays for plasma pancreatic enzymes, especially cationic trypsin, are good tools to diagnose pancreatic pathology. The trypsin assay is very sensitive. Its detection limit is 300 pg/ml. The plasma level of this enzyme appears to be representative of pancreatic function. This assay was shown to be valuable in the diagnosis of acute pancreatitis, and to follow the course of the disease. In chronic pancreatitis, it enables assessment of residual function of the organ. In the terminal stage of this disease, very low values were found. Used as a screening test, the assay allowed early detection of cystic fibrosis.

Acute Disease↗
PubMed1983

Effects of droperidol on respiratory drive in humans.

The sensitivity of the respiratory center following a single 0.3 mg X kg-1 iv dose of droperidol was determined in eight healthy volunteers by using carbon dioxide (CO2) rebreathing and mouth occlusion pressure measurements (P0.1). There were no significant differences in the mean slopes of the minute ventilation/partial pressure of CO2 (VE/PCO2) and log P0.1/PCO2 relationships between control measurements and those made 30, 60, 90, 150, and 240 min after droperidol administration. However, individual variations in response were present, one subject showing significant (approximately 50%) depression of respiratory drive.

Adult↗
PubMed1983

Phenylalanine hydroxylase. Evidence that the enzyme from human liver might not be a phosphoprotein.

Phenylalanine hydroxylase from fresh human liver was purified to homogeneity with a 60% yield by a three steps procedure involving hydrophobic chromatography on Phenyl-Sepharose, ion exchange chromatography on DEAE-Cellulose and High Performance gel permeation chromatography. The purified native enzyme had an estimated molecular weight of 165,000. It gave a single band on Sodium Dodecylsulfate polyacrylamide gel electrophoresis under an estimated molecular weight of 55,000. Neither the purified human enzyme, nor that present in a liver extract could be activated under phosphorylating conditions. Moreover, the purified human liver phenylalanine hydroxylase was found to be devoid of protein-bound phosphate and no phosphate could be incorporated from [32P]-ATP in the presence of cyclic-AMP - dependent protein kinase. These data suggest that phenylalanine hydroxylase from human liver, unlike that of rat liver, might not be a phosphoprotein.

Amino Acids↗
PubMed1982

Thoracoscopic lung biopsy. Experimental and clinical preliminary study.

We have investigated thoracoscopic lung biopsy (TLB) as an alternative to surgical biopsy. TLB was performed under mild general anesthesia, with two openings: one for the telescope, and one for a 5 mm in diameter biopsy forceps connected to diathermocoagulating device. TLB was first tested on 14 dogs (22 TLB) and then on 75 subjects (77 TLB): 35 patients with pleural diseases and 40 patients with undiagnosed lung diseases despite previous investigations including transbronchial biopsy. TLB yielded a high rate of adequate samples (up to 5 x 5 x 5 mm) in both experimental (95 percent) and clinical series (96 percent). Overall sensitivity equalled 923 percent, ranging from 70 percent in peripheral localized lesions to 100 percent in diffuse lung diseases. The mean period of systematic drainage was 3.4 +/- 0.3 days, and the main complications we encountered were one transient blood-streaked sputum specimen and eight localized pneumothoraces during drainage. TLB is indicated when other medical procedures have failed, and has thus proved, in this series, to be as sensitive as surgical biopsy with less morbidity and no mortality.

Animals↗
PubMed1982

[Heterogeneity of leucinosis. Correlations between clinical manifestations, protein tolerance and enzyme deficiency].

Maple syrup urine disease (MSUD) is an inborn error of branched-chain aminoacid (BCAA) catabolism due to a defect of BC ketoacid decarboxylation. Beside the classical form of the disease, general variant forms have been recently reported. From our personal experience in 21 patients consisting of 14 patients with classical MSUD and 7 patients with "variant" forms (1 intermittent, 2 subacute forms, 1 lipoamide dehydrogenase deficiency and 3 composite heterozygotes), we tried to correlate clinical features with protein tolerance and enzyme activity. All classical forms share an acute neonatal presentation, with a low leucine tolerance (m +/- SD = 465 +/- 88 mg per day), and a very low enzyme activity (m +/- SD = 2.5 +/- 1.5% of controls), mild variations being consistent with a possible polyallelism within this group. All "variant" forms share a late onset with a reasonable leucine tolerance (2-3 grams per day) and a fair enzyme activity, ranging from 7 to 20% of controls. However, no strict correlation could be found between the severity of the outcome and the extent of the residual enzyme activity, since acute episodes or chronic deterioration occurred even in "variants", irrespective of the level of their enzyme activity. Finally, our data suggest that variant forms could result from a composite heterozygotism, combining heterozygotism for the gene of classical MSUD and heterozygotism for a "petite" mutation, undetectable when isolated. The occurrence of classical MSUD and "variant" forms of the disease within a single family of our series further supports this hypothesis.

Adolescent↗
PubMed1981

Serotonin and dopamine synthesis in phenylketonuria.

Two regulation systems of the serotonin and dopamine biosynthesis in patients with classical and atypical PKU were investigated. In classical PKU, the serotonin and dopamine biosynthesis is inhibited by high L-phenylalanine in blood and tissues. The dopamine formation in vivo was inhibited by phenylalanine blood concentrations higher than 25 mg/dl: the serotonin formation was inhibited even at a phenylalanine blood concentration of only 8 mg/dl. In two patients with dihydrobiopterin synthetase deficiency, the dopamine, and even more pronounced the serotonin, excretions are considerably reduced. The dopamine excretion was reduced to about 50% and the serotonin excretion to only 10% compared to controls. Under BH4 therapy (16 mg daily), the dopamine values increased about twice, serotonin threefold and the phenylalanine blood concentration normalized to 1-1.5 mg/dl. On loading a patient with BH2 synthetase deficiency with 50 mg/kg deuterated tryptophan-d5 and 150 mg/kg deuterated tyrosine d2 (phenylalanine blood concentration of 16 mg/dl), deuterated dopamine d1 and serotonin d4 could only be formed in detectable amounts after BH4 administration. During BH4 therapy the amount of dopamine d1 and serotonin d4 formed was lower than but comparable to normal controls.

Dopamine↗