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R Aquaron

Publications and source records attributed to R Aquaron.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Human oculocutaneous albinism. From clinical observation to molecular biology].

Human oculocutaneous albinism (OCA) is a heritable metabolic defect transmitted as an autosomal recessive trait and characterized by a hypopigmentation of skin, hair and eyes. This defect is mainly due to an altered or absence of tyrosinase activity, the key enzyme of eu-and pheo-melanin synthesis. It is a seldom condition in white peoples but more frequent in Africans and in Afro-Americans. Albinos, especially in tropical settings, have high prevalence of solar keratosis and squamous cell carcinoma. Ocular defects characteristics of OCA are photobia, nystagmus and decreased visual acuity. Two forms of OCA have been distinguished in 1970 on the basis of their genetic, clinical, biochemical and ultrastructural characteristics: type I i. e. tyrosinase negative and type II i. e. tyrosinase positive. Actually 10 forms are described. Human tyrosinase gene has been mapped to chromosome 11 (q14-21) and cloned. It is formed by 5 exons. Several different human tyrosinase gene mutations have been identified in patients with type I-A OCA. Non sense, misense and frameshift mutations result in altered or absence of tyrosinase activity.

Albinism, Oculocutaneous↗
PubMed1992

[Hereditary porphyria and acquired porphyria in the child. Five case reports].

Two cases of inherited porphyrinopathies and three cases of acquired porphyrinopathies are described. The two inherited cases were cutaneous porphyrias with 50% reduction of enzyme activities: one case of erythropoietic protoporphyria in a 2 year-old male and one case of familial cutaneous porphyria in a 7 year-old boy. The three cases of acquired porphyrinopathy included one case of lead poisoning in a 3 year-old boy and 2 cases of hereditary tyrosinemia in 1 and 2 year-old infants. Urinary and erythrocytes porphyrins and precursors (5 aminolevulinic acid and porphobilinogen) levels were used for diagnosis and to follow the response to treatment.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

[Neurological, dermatological and biological manifestations of porphyria variegata. A study of 3 families of Italian origin in Marseilles area].

Three kindreds of Italian descent with variegate porphyria are described. These families are now living in Marseilles and surrounding regions. The first kindred originating from Torre del Greco, near Naples, is living in Arles. This family includes two propositi who experienced an acute attack with visceral and neuropsychiatric manifestations. The family's survey was carried out by measuring protoporphyrogen oxidase (PO) activity in lymphocytes (normal values = 4.8 +/- 1.2). Seven of the 20 subjects tested, beside the two propositi, were found to be asymptomatic carriers (PO < 3.6). The first index patient, a 41-year old man, was first observed at the age of 31 with acute and psychiatric manifestations after rifampicin treatment; the cutaneous symptoms appeared one year later. For the second propositus, a woman presenting with abdominal and psychiatric manifestations, the age of onset was 38 years; the acute attack had no recognizable cause; she had mild skin lesions and initially was incorrectly diagnosed as intermittent acute porphyria; the diagnosis of variegate porphyria was only established at the age of 50 years. The second family, originating from la Spezia and Vernazza, is living in Marseilles. The propositus, a 50-year old man, developed cutaneous symptoms at the age of 30. A diagnosis of porphyria cutanea tarda was initially made. The first and unique acute attack with abdominal and neurological manifestations recurred at the age of 41. The diagnosis of variegate porphyria was established on laboratory data. Physical stress was probably the cause of the acute attack. Beside the propositus, out of 9 subjects tested 6 were asymptomatic carriers.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Pain↗
PubMed1990

Oculocutaneous albinism in Cameroon. A 15-year follow-up study.

Oculocutaneous albinism in Cameroon was studied from 1972 to 1987. Two hundred and seventy-three albinos (160 males and 113 females) were registered. The sex ratio of 1.42 (male/female) was significantly different from unity but this apparent discrepancy may be explained by social and geographical reasons. The highest prevalence occurred in the Bamileke group (190/273 albinos, i.e., 70%) for which the rate was 1 in 7,900, using an estimate of 1,500,000 Bamileke people. The high frequency of the albino gene was thought to result from a greater inbreeding tendency, to the special organization of the Bamileke society in mini-states or kingdoms and to a founder effect in the case of Balengou kingdom. The death of albinos was mainly due to skin cancer induced by solar radiation during the second, third or fourth decade. Cameroon, located from 2 degrees to 12 degrees above the equator, is sunny throughout the year. Registering all albinos early in life, educating them to prevent the damaging effect of the sun (protective clothing, sun-screening agents and indoor occupations), detecting and treating premalignant and malignant lesions are of great importance in this country.

Adolescent↗
PubMed1990

[Study of two goitrous endemic areas in Niger: Belley-Koira and Tiguey-Tallawal].

The present work reports the clinical and laboratory findings in two endemic areas in Niger: Tiguey-Tallawal and Belley-Koira. The goitrous subjects (n = 293), mainly children and adolescents, have clinical evidence of euthyroidism but with biological criteria of hypothyroidism in 25% of cases as shown by the decrease of the total serum T4 and the increase of serum TSH. Iodine deficiency intake evaluated by the determination of urinary iodine in single urine specimens is the permissive and main factor for goiter endemicity = 14 +/- 7 micrograms/l in Belley-Koira (n = 99), 26 +/- 23 micrograms/l in Tiguey (n = 155) and 25 +/- 19 micrograms/l in Tallawal (n = 95). The single intramuscular injection of iodized oil (240 mg of iodine) constitutes an extremely effective way of correcting iodine deficiency: decrease of volume or disappearance of goiter among 291 subjects out of 362 i.e. 80%, twelve months after the injection. The diffuse goiter, more numerous (n = 270) than nodular goiter (n = 92) are corrected with more efficiency (85% versus 50%). We also noted that non goitrous subjects living in these two endemic areas show a severe iodine deficiency (urinary iodine: 33 +/- 18 mu/l; n = 70 = 76) while those living in non endemic areas present a moderate or a low iodine deficiency, respectively in Niamey (urinary iodine: 48 +/- 36 micrograms/l; n = 200) and in Tamou (urinary iodine: 80 +/- 29 micrograms/l; n = 69). Severe, moderate and low iodine deficiency seem to be correlated with nutritional habits: mil in endemic areas, mil and meat in Niamey and mil, meat, milk and fish in Tamou. The nutriments eaten in Niger have a low iodine level except ewe milk: salt (270 to 7100 micrograms/kg), woman milk (40 +/- 21 micrograms/l) cow milk (22 micrograms/l) goat milk (50 micrograms/l), ewe milk (294 micrograms/l). Salt consumption, evaluated by the determination of urinary chloride, is adequate. Prophylaxis by iodinated salt should be well accepted. No other factors than iodine deficiency in the etiology of endemic goiter, mainly nutritional (goitrogens or protein-calorie malnutrition) can be evoked to explain clinical and biochemical discrepancies between subjects living in the same morbid territory.

Adolescent↗
PubMed1990

[Metabolic risks in surgical hysteroscopy].

Operative hysteroscopy is often carried out using glycine as an irrigant. This solution has interesting properties but also metabolic effects that are very well known by urologists. This study is concerned with the biological changes that have occurred after one hundred surgical hysteroscopies of which twenty nine were carried out using glycine. In hysteroscopy the significant variations are concerned with blood levels of protein, the haematocrit, changes in sodium levels and glycaemia. 44.9% of patients had changes greater than 5% as compared with the pre-operative levels. These changes concerned the haematocrit readings and in 57.1% the changes in protein in the blood and in sodium in 12%. The haematocrit changes, the protein changes and to a lesser degree the sodium changes could be correlated with one another but not with changes in glycine levels in the blood. Whatever the pathology inside the uterus, glycine went through in equal quantities. It was particularly significant when there was perforation of the uterus. It is linked to the glycine balance and to the length of time the operation had taken. When a mean quantity of fluid of 2.6 litres was used to irrigate, levels after the operation as compared with before the operation had multiplied 4.5 times. This corresponds to the dosage of glycine used. In five patients out of twenty nine post-operative quantities were 10 times those before operation. The consequences of these changes in glycine levels are variable and seem to be more significant in women who have never been pregnant or who are very heavy. Using vasoconstrictor agents does not alter these metabolic changes.

Adult↗
PubMed1990

Calmodulin content and distribution in six human melanoma cell lines.

Calmodulin content and distribution between soluble and particulate fractions were determined by radioimmunoassay in six human melanoma cell lines exhibiting differences in tumor origin (primary or metastatic), degree of tumorigenicity and of pigmentation (amelanotic or melanotic). The results indicate that a) total, soluble and particulate calmodulin levels expressed as ng/10(6) cells or ng/micrograms of proteins remained constant for five out of six cell lines when cells grew from subconfluency to confluency. For IGR 37 line, derived from metastatic melanoma, the calmodulin content decreases from 2.39 to 1.27 ng/micrograms protein for total calmodulin, from 2.17 to 1.52 ng/micrograms protein for soluble calmodulin and from 2.61 to 1.02 ng/micrograms protein for particulate calmodulin, b) total, soluble and particulate calmodulin levels expressed as ng/microgram proteins were twofold (at confluency) to fourfold (at subconfluency) higher in the two cell lines from metastatic origin, IGR 37 and IPC 167. As for example, for total calmodulin, values in IGR 37 and IPC 167 cell lines, were, respectively at subconfluency, 2.39 and 2.31 ng/micrograms protein as compared with the four other cell lines: 0.76 to 0.96 ng/micrograms protein and at confluency: 1.27 and 1.98 ng/micrograms protein as compared with the four other cell lines: 0.76 to 0.90 ng/micrograms protein, c) ratio of calmodulin between soluble and particulate fractions was about 1 for the two autologous cell lines IGR 37 and IGR 39 and varies from 2 to 3 for the four other cell lines.

Calmodulin↗
PubMed1986

Radioiodination of tyrosine residue(s) of ox testis and of wheat germ calmodulins.

Radioiodination of the two tyrosine residues (Tyr-99 and Tyr-138) of ox testis calmodulin was performed using several methods, and studied through the specific activity, and the [125I]iodoamino acid analysis of the radiolabeled calmodulins. Hydrolysis by thrombin of 125I-calmodulin labeled by the lactoperoxidase method and subsequent isolation of peptides TM1 and TM2 by gel electrophoresis showed preferential labeling by 125I of Tyr-99 (TM1) over Tyr-138 (TM2). Analysis of [125I]iodoamino acids of radiolabeled TM1, TM2 and calmodulin demonstrated that [125I]monoiodotyrosine was predominant, the remainder being [125I]diiodotyrosine. Radioiodination of wheat germ calmodulin, which contains a single tyrosine residue (Tyr-139), showed that only TM2 was labeled by 125I on the Tyr-139 residue and also on the His-108 residue (radiolabeled monoiodotyrosine, diiodotyrosine and monoiodohistidine being present).

Animals↗
PubMed1986

[AMP deaminase deficiency (myoadenylate deaminase). Disease or syndrome?].

Two recent publications have shown the advantage of understanding the deficit in AMP desaminase in rheumatology. On this subject, the authors report 4 cases of deficit in AMP desaminase. The first one includes a semiology made of pain, and stiffening, the second case is discovered in the course of a primary muscular disease. The third case is present during the first stage of a spinal cord compression. The fourth case is a muscular deficit accompanied with a histological picture of inflammation, considered initially as a chronic polymyositis, but explained secondarily as a pseudo-polymyositis form of facio-scapulo-humeral dystrophy. In this respect, the cases from the literature are divided into three groups: asymptomatic, infraclinical forms, forms occurring in the course of specific diseases (muscular diseases, spinal cord diseases, inflammations of the connective tissues, metabolic diseases), apparently isolated forms. In the latter, emerges a semiology made of pain, cramps, stiffening of the lower extremities occurring on exertion. However, the specificity of the symptoms remains to be discussed.

AMP Deaminase↗
PubMed1985

[Demonstration of calmodulin in cultured human malignant melanocytes by indirect immunofluorescence].

Using calmodulin antibody, evidence for the presence of calmodulin, a calcium-binding protein modulator of numerous enzymes was shown by indirect immunofluorescence in 9 cell lines of cultured human malignant melanocytes. Calmodulin was localized in cytoplasm and in higher concentration in the perinuclear region. These observations agree with the distribution of calmodulin-binding proteins in cytoplasm and membranes.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1983

Isolation and purification of ceruloplasmin in oculocutaneous albinism, Menkes' disease, Wilson's disease and pregnant women.

A method is reported for isolation and purification of human ceruloplasmin and apoceruloplasmin from serum. It involves a rapid and mild procedure by ion exchange chromatography on DEAE-Sephacel using a pH and ionic strength concave gradient. It was applied to serum of patients with oculocutaneous albinism, Wilson's disease, Menkes' disease and pregnant women. The ceruloplasmin obtained by this method is undegraded, and homogeneous by physico-chemical and immunochemical analysis.

Albinism↗
PubMed1982

[Determination of plasma catecholamine. Effects of glucagon administration].

Basal plasma dopamine (DA), Norépinephrine (NE) and Epinephrine (E) were determined in controls (n = 15) essential hypertension (n = 19) and Pheochromocytoma (n = 9). Plasma NE was significantly higher in essential hypertension than in control and in 5 cases, plasma NE or E was 3 SD above mean control values. In 8/9 pheochromocytomas DA, E or NE were significantly elevated. In 1 case, catecholamine levels were within normal range during normotensive period. When a provocative glucagon test (1 mg I.V) was performed in controls, there was no change in blood pressure DA and NE levels, but a significant increase in plasma E 2.5 and 5 min. after injection. Similar results were obtained in 8/10 cases of labile hypertension. However in 2 cases plasma NE or E increased significantly without elevation in blood pressure. In 3/4 pheochromocytomas under normotensive phase, blood pressure and plasma catecholamines increased significantly; however in 1 case, no change was observed.

Adrenal Gland Neoplasms↗
PubMed1978

[Serum carotenoids and vitamin A in melanodermic and albino subjects in Cameroon].

Vitamin A nutritional status as assessed by carotenoid and vitamin A assays in sera collected in various parts of Cameroon prooved to be of good value. Palm oil rich diets lead to high seric carotenoid concentrations and tissular accumulation which is particularly visible on the palms and soles of melanodermic and albinos subjects.

Albinism↗