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Biomedical subjects

A Carnevale

Publications and source records attributed to A Carnevale.

At least 37 records · Page 2Linked to original sources

Renal tubular acidosis in the Silver-Russell syndrome.

Several patients with the Silver-Russell syndrome (SRS) attending our Genetics Clinic were diagnosed as having persistent metabolic acidosis. Since this abnormality has not been reported previously in the SRS, we reexamined 33 SRS patients to evaluate the frequency and type of metabolic acidosis, the clinical and laboratory findings, and the growth pattern in SRS patients with and without metabolic acidosis. Among them, 14 had a consistent decrease in HCO3- levels. Renal studies in acidotic patients showed urine pH of 5.8 and 24 h urine calcium of < 2.4 mg/kg/24 h; serum creatinine, excretion of glucose, and amino acids were normal, as were renal ultrasound and excretory urography findings. These data supported the diagnosis of renal tubular acidosis, probably type II; the patients were treated with oral bicarbonate and acidosis was corrected successfully. Clinical manifestations were similar in acidotic and non-acidotic patients. The nutritional indices at diagnosis and at last evaluation (at least 8 months after diagnosis) were abnormally low in all patients; however, acidotic patients, treated with bicarbonate, showed an improvement of nutritional status particularly in the weight/height index, although the difference between groups after follow-up did not reach statistical significance. We suggest that metabolic acidosis due to renal tubular acidosis, probably type II, may occur in children with the SRS and should be looked for and treated in all patients.

Abnormalities, Multiple↗

Mild cystic fibrosis disease in three Mexican delta-F508/G551S compound heterozygous siblings.

We describe three delta-F508/G551S compound heterozygous siblings with a mild CF phenotype, characterized by mild chronic pulmonary disease, pancreatic sufficiency and increased sweat chloride levels. PCR-mediated site-directed mutagenesis detected the delta-F508 mutation on one allele, and the G551S mutation was detected by SSCP and sequence analysis of exon 11. Two previously described sisters who were homozygous for the G551S mutation had a very mild phenotype with normal sweat chloride concentrations. In our patients the mild phenotype resulted from the combined effect of the mild G551S allele with the severe delta-F508 allele.

Adult↗

Identification of the I507 deletion by site-directed mutagenesis.

We describe a compound heterozygous delta-F508/delta-I507 cystic fibrosis patient. Molecular analysis by polymerase chain reaction (PCR)-mediated site-directed mutagenesis showed the 219 bp fragment observed in delta-F508 homozygotes. The father showed a delta-F508 heterozygous pattern while the mother and sister showed a normal pattern. There were four possibilities to explain these results: a) the patient was a delta-F508/delta-I507 compound heterozygote, because the delta-I507 allele fails to amplify when analyzed with delta-F508 primers due to a double mismatch between the primers and template; b) uniparental isodisomy; c) nonmaternity; and d) sample processing mix-up. We then tested for the delta-I507 mutation using specific primers with a single base mismatch, and we found that the patient was in fact a compound heterozygote who inherited the delta-F508 mutation from the father and the delta-I507 from the mother. We underscore the need to detect this rare deletion in patients showing a delta-F508 homozygous pattern when one parent, particularly the father, is a noncarrier.

Alleles↗

Nerve growth factor (NGF) in cerebrospinal fluid (CSF) from patients with various neurological disorders.

It has been recently shown that NGF is not only involved in the survival and development of sympathetic and neural crest-derived sensory neurons, but also in some mechanisms of the immune system. For this reason, we studied the content of NGF in CSF samples from patients with diseases in which neuroimmunological mechanisms seem to be involved (multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer disease, chronic relapsing polyradiculoneuritis, Guillain-Barré syndrome, and tumors of the nervous system), as well as from a number of normal control subjects. We setup an ELISA aimed at the beta subunit of NGF, obtaining good validation tests and a detection limit of 28 pg beta NGF per ml. None of the samples was found to contain detectable levels of NGF and, when a concentration method for sample enrichment was used, only one patient was NGF-positive. This suggests that NGF is probably not involved in the neuroimmunological mechanisms underlying some inflammatory and degenerative diseases of the nervous system.

Antibody Specificity↗

Balanced reciprocal whole arm translocation t(3;9): analysis by fluorescence in situ hybridisation.

A patient with Turner phenotype was found to carry two de novo chromosome aberrations: a 45,X line and a whole arm reciprocal translocation t(3;9). Fluorescence in situ hybridisation on metaphase cells using alpha satellite DNA for chromosome 3 and beta satellite and 'classical' satellite DNA for chromosome 9 showed that the centromeric region of chromosome 3 was retained in the 3q9q translocation derivative, as was the secondary constriction heterochromatin of chromosome 9. No signals were observed in the 3p9p derivative with the three probes. This suggests that the breakpoints were on 3p11 and 9q11. The karyotype was 45,X,t(3;9)(3qter-->3p11::9q11-->9qter; 9qter-->9q11::3p11-->3pter).

Adult↗

Tetrasomy 18p in two cases confirmation by in situ hybridization.

Two cases with an extra small metacentric chromosome are described. Classic cytogenetic analysis was insufficient for identification of the marker origin. High resolution banding and fluorescence in situ hybridization (FISH) using a chromosome specific painting probe indicated that both marker chromosomes originated from chromosome 18. The correlation between phenotype, cytogenetics and FISH results allowed us to conclude that the patients are tetrasomic for 18p. A comparison of the clinical features of our two patients with other twelve previously reported patients where tetrasomy 18p was confirmed, is also presented.

Aneuploidy↗

Frequency of delta F508 in a Mexican sample of cystic fibrosis patients.

This paper reports the frequency of the delta F508 mutation in a cohort of 50 Mexican patients with cystic fibrosis (CF). The mutation was detected by PCR mediated site directed mutagenesis. delta F508 was found in 39% of CF chromosomes, a frequency lower than that reported in Argentina and Spain. The high rate of CF cases who die undiagnosed, the ethnic origin of Mexican populations, and the limited number of cases studied could account for the low frequency of the delta F508 mutation found in this preliminary report.

Adolescent↗

[A molecular study of the delta-F508 mutation and genetic analysis of a sample of cystic fibrosis patients].

The delta-F508 mutation was investigated in 39 index cases with cystic fibrosis (CF) using PCR-mediated site-directed mutagenesis. Eight patients were delta-F508 homozygous, 16 were delta-F508/unknown mutation compound heterozygous and 15 had unknown mutations in both alleles. Thus, delta-F508 was present in 41% of CF chromosomes and this frequency is lower than the observed among Northern European and North American Caucasians (70%), Southern Europe populations (50%) and Northern Mexico (59.1%). Age at present, age of onset of clinical data and age at diagnosis were lower in the group of delta-F508 homozygous, although the difference was not statistically significant. In this same group growth deficiency was more frequent than in the others. Among 84 brothers, 25 (28.9%) were affected. Pedigrees analysis showed that among 782 cousins, two were affected and in two families, other relatives born to non consanguineous parents had CF. These data suggest that, probably, the disease and heterozygous frequencies do not differ from the reported in Caucasians (1/2500 and 1/25 respectively). The low frequency of delta-F508 mutation could be due to the small size of the sample but it can also be explained by the heterogeneous genetic composition of the population living in Mexico or because a number of delta-F508 homozygous patients die at early ages without being diagnosed.

Adolescent↗

Delayed membranous cranial ossification in a mother and child.

We report on a girl and her mother with delayed intramembranous ossification of the cranial vault. The 11-month-old girl had a large ossification defect involving parietal bones, squamous portion of temporal bones, and interparietal region of occipital bone, while the mother showed a complete ossified cranial vault with flat posterior parietal region and prominent occiput. Both had a similar face characterized by frontal bossing, hypertelorism, downward slant of palpebral fissures, flat nasal bridge, and short midface. On reviewing the literature, we concluded that these cases may be a dominant transmitted ossification defect with characteristic face, different from the cranium bifidum-parietal foramina entity.

Abnormalities, Multiple↗

Anthropometric studies in five children and their mother with a severe form multiple epiphyseal dysplasia.

We report on a form of multiple epiphyseal dysplasia with striking acromelic shortness in a woman and five of her ten children. The somatometric and metacarpo-phalangeal pattern profile of the affected individual showed short limb dwarfism and shortness of all the tubular bones of the hand. Epiphyseal irregularities and shortness of the 4th metatarsal bones were outstanding. The disorder showed a dominant and probably autosomal pattern of inheritance with variability of expression. The measurement of metacarpo-phalangeal profiles allowed an objective and quantitative assessment of brachydactyly. In the family reported here, there was a clear discrepancy between the severity of shortness of hands and feet and the severity of shortness of stature. This family also illustrates the effects of a single gene in a large kindred, therefore describing the range and variability of a phenotype not otherwise available.

Anthropometry↗

Effectiveness and side effects of two different doses of caffeine in preventing apnea in premature infants.

The effectiveness of caffeine citrate in preventing idiopathic apnea in premature infants was evaluated. Thirty-seven preterm infants born before the 32nd week of gestation were studied. After an intravenous loading dose of 10 mg/kg of caffeine citrate, two different oral maintenance regimens were followed: 5 mg/kg in Group I and 2.5 mg/kg in Group II. A significant decrease in the number of apneic spells occurred in both treated groups as compared with a control group. In Group II, the frequency of side effects such as tachycardia and gastrointestinal intolerance was significantly lower than in Group I. Group II theophylline plasma levels were significantly lower than those of Group I. The lower Group II theophylline levels presumably explain the reduced frequency of side effects.

Apnea↗

[Spondyloepiphyseal dysplasia tarda with progressive arthropathy: 2 siblings affected].

We described a Mexican family whose parents were consanguineous. Therefore two children were affected by a progressive arthropathy with deformity in all finger joints, restricted joint mobility and broad major joints. This condition was diagnosed like atypical juvenile rheumatoid arthritis (JRA) because the test for serum rheumatoid factors and antibodies were negative and failed to respond to anti-rheumatoid treatment. However their radiographic studies showed the spine with universal platyspondyly, enlargement epiphyses of the hands, the absence of destructive and the presence of the dysplastic bone changes. These manifestations permit us to do the diagnosis of spondyloepiphyseal dysplasia tarda with progressive arthropathy. In this report we suggest that a complete radiologic study of the patient will allowed to diagnosis this hereditary autosomal recessive entity; likewise it will let us differ of JRA and others polyarticular conditions of childhood.

Child↗

[Chromosomal translocation (2;13) in disseminated rhabdomyosarcoma].

A 12-year-old male with a disseminated alveolar rhabdomyosarcoma is reported. The diagnosis was difficult because of the clinical manifestations and the histological patterns of the bone marrow and a chest wall tumor. Diagnosis was confirmed through the histologic picture of a gum biopsy and the karyotype of the tumoral cells of the bone marrow. Chromosome study revealed a hypotetraploid cell line with the translocation (2;13) characteristic of this type of neoplasias. The usefulness of chromosome studies in solid tumors of childhood is emphasized.

Biopsy↗

Effect of mitomycin C and bromodeoxyuridine on Fanconi anemia lymphocytes.

The authors studied the effect of mitomycin C (MMC) and bromodeoxyuridine (BrdU) on the induction of chromosome aberrations on lymphocytes of four patients with Fanconi anemia (FA) and of one normal subject. A control culture and six experiments were designed to test the possible synergic effect of MMC and BrdU. Their results revealed no evidence of MMC-BrdU synergism on the induction of chromosome aberrations in FA lymphocytes. However, chromosomes showed more damage when FA cells were harvested 24 h after MMC stress than when cells were harvested shortly after treatment. This can be explained by a DNA repair defect or by a toxic effect of oxygenation of cells during the procedure.

Bromodeoxyuridine↗

Pharmacokinetic aspects of caffeine in premature infants.

The pharmacokinetic profile of caffeine was studied in 15 premature infants. Five infants received a single intravenous dose of 10 mg/kg of caffeine citrate 100% at birth and on the 15th day of life. Ten neonates were studied during daily therapy with caffeine for prophylaxis of idiopathic apnea. The time course of plasma and urinary concentrations of caffeine and theophylline shows that caffeine is transformed to theophylline at birth, while total urinary xanthines decrease significantly (p less than 0.001) 72 h after the loading dose given on the 15th day of life. During the whole period of treatment, the decrease in total urinary xanthines and the constant urinary percentage elimination of theophylline are due to further metabolism of theophylline. We confirm that the intravenous loading dose of 10 mg/kg can rapidly obtain therapeutic blood levels of caffeine. We also confirm that the maintenance therapy can be carried out with a single daily dose.

Biotransformation↗

[Congenital multiple arthrogryposis. Clinical and genetic study].

Forty six cases of arthrogryposis multiplex congenital (AMC) were studied at the Genetic Departament of the Instituto Nacional de Pediatría (México). Three were familial cases, two of them suggesting an autosomal recessive inheritance and one probably dominant. Almost half of the patients were the product of the first pregnancy. The limbs abnormalities allowed the classification of cases in: generalized AMC (54%), lower limbs (30%), upper limbs (5%) and distal (11%). The commonest associated defects were hemangioma, round face and micrognathia. It is concluded that AMC produces severe limitations and variable degree of severity. Associated defects are common and must be explored. Although the majority are sporadic cases the pedigree may show a mendelian inheritance and genetic counseling is needed.

Abnormalities, Multiple↗

Trisomy 9 mosaicism in a girl with multiple malformations.

A one-year-old girl with a mosaicism for an extra chromosome 9 is reported. Clinical findings included severe growth and mental retardation, frequent respiratory infections, peculiar face, skeletal and craniofacial abnormalities, seizures, spasticity, cardiopulmonary, gastrointestinal and genitourinary alterations. These findings were compared to those of the 10 other previously reported cases of trisomy 9 mosaicism. This helps to define the most constant phenotypical characteristics and most frequent major malformations which occur in trisomy 9 mosaicism. It is noteworthy that the reported percentage of trisomic cells was different in lymphocytes and in fibroblasts in each case.

Abnormalities, Multiple↗

Mitomycin C effect on Robertsonian translocations.

Centromeric breaks and dissociation of Robertsonian translocations have been suggested to be the cause of a few cases of mosaicism. One possible explanation for dissociation could be that the point of reunion of the two acrocentrics would be a structurally fragile site. Mitomycin C (MMC) treatment of lymphocyte cultures from 6 patients having a Robertsonian translocation showed that in cases 1 and 2, who were already mosaics, MMC induced a statistically significant increase of the number of cells with the dissociated translocation. In the remaining cases a preferential centromeric break on the translocation was observed, indicating instability of the region. The relationship of monocentric and dicentric translocations, the viability of the cells resulting from the dissociation, and the clinical implications are discussed.

Cell Line↗