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Biomedical subjects

A Daniel

Publications and source records attributed to A Daniel.

At least 73 records · Page 4Linked to original sources
PubMed1985

NOR activity and centromere suppression related in a de novo fusion tdic(9;13)(p22;p13) chromosome in a child with del(9p) syndrome.

A female infant with del(9p) syndrome was found to have the karyotype 45,XX,tdic(9;13)(p22;p13) de novo. In the translocation chromosome, various combinations of AgNOR activity and inactivity were found with suppression of either the 9 or neither centromere. These phenomena of discontinuous centromeric suppression and variation in NOR activity in the one chromosome were scored on AgNOR, GTG, and a combination of AgNOR- and GTG-banded preparations. With AgNOR staining, 15.8% tdic chromosomes were AgNOR-positive, and this coincided (in preparations with GTG banding only) with 16% tdic chromosomes with a nonstaining gap present at the NOR site. This suggested that when the NOR-nonstaining gap was present the AgNOR staining would be positive; this was confirmed by the absence of gaps in combination AgNOR-GTG-banded preparations. In cells with tdic-NOR-negative chromosomes, equal proportions of cells with the 13 or both centromeres constricted were observed, but in cells with tdic-AgNOR-positive chromosomes there was only half the proportion of tdic chromosomes with both centromeres constricted; ie, there was a (significant) tendency towards inactivity of the NOR when both centromeres were constricted in the tdic chromosome. Therefore, the 2 phenomena, variation in NOR activity and centromeric suppression, are interrelated in this case.

Centromere↗
PubMed1984

Discovery of a connective tissue dysplasia in the Martin-Bell syndrome.

The fact that a connective tissue dysplasia is a component of the Martin-Bell syndrome was a fortuitous discovery. A 26-month-old developmentally delayed boy had many signs of a connective tissue dysplasia for which he was referred to a University center where he was found to be fragile (X)-positive without confirmation of a connective tissue problem. Sensitized by these events and observations, we were able to predict at a glance in an unrelated family the fragile (X)-positive status of 2 subsequently referred brothers with mental retardation and prominent manifestations of connective tissue dysplasia. Thus, the Martin-Bell syndrome is an incompletely recessive, pleiotropic trait involving CNS, testes and connective tissues. The characteristic facial appearance of affected males largely represents interaction of mental retardation, congenital CNS based muscle hypotonia and connective tissue dysplasia. At the 1983 NIH workshop on XLMR there was a general consensus that a connective tissue dysplasia is a component of the Martin-Bell syndrome, a fact since confirmed by others on the basis of objective measurements of finger joint hypermobility and frequent presence of mitral valve prolapse.

Abnormalities, Multiple↗
PubMed1984

Constitutive fragile sites 1p31, 3p14, 6q26, and 16q23 and their use as controls for false-negative results with the fragile(X).

Fragile(X) estimations in fragile(X)-mental retardation hemizygotes or heterozygotes can become falsely negative in stored blood (lymphocytes). This was shown in blood stored (before culture) at 4 degrees C, room temperature (25 degrees C), 37 degrees C, and 39 degrees C for 1-4 days. After storage, blood was cultured in Ham's F10-5% FC serum with 0.1 microM FUdR and scored for fra(X) and the constitutive fragile sites at 3p14 and 6q26. It was found that the proportion of cells expressing the fragile(X) and the 3p14 site varied inversely with the temperature and time of storage. In addition, 50 patients and controls were scored for the three latter sites after routine 72-96-hr culture in F10-0.05 or 0.1 microM FUdR. The 3p14 site was detected in every individual tested in a mean +/- S.D. of 11.3 +/- 3.2% of cells (0.1 microM FUdR). It was found that this site was FUdR dose dependent whereas the 6q26 site was not. The 3p14 (but not the 6q26) site is therefore suitable as a control site for the FUdR effect. It is proposed that repeat studies are necessary when less then 4% 3p14 sites are present in specimens from males referred for fra(X) estimation. Other constitutive fragile sites (eg, 1p31 and 16q23) can also be used.

Chromosome Fragile Sites↗
PubMed1984

Interstitial deletion of chromosome 3p: report of a patient and delineation of a proximal 3p deletion syndrome.

We report on a patient with a de novo interstitial deletion of the proximal portion of the short arm of chromosome 3 (p12----14.2). The deleted portion excludes the constitutive fragile site assigned to band 3p14. The phenotype of the patient, together with that of three previously reported cases, seems to be sufficiently characteristic to allow the delineation of a proximal 3p deletion syndrome.

Abnormalities, Multiple↗
PubMed1984

Experimentally induced inflammation of the guinea pig palatal mucosa by injection of a microcrystalline suspension of monosodium urate.

The injection of microcrystals has been frequently used to induce inflammatory reactions in various sites (i.e., joints, skin, pleural cavity). The aim of this study was to create a reproducible experimental animal model of buccal inflammatory reaction. The monosodium urate (MSU) crystals were obtained following the technique described by Denko and Whitehouse (1976). After injection in the palatal mucosa, biopsies were sampled and analyzed using the stereologic technique described by Weibel et al. (1966). This analysis shows 1) a decrease of the collagen volume fraction in the hours after the injection; 2) the presence of vasculitis and edema during the 12 hours after the injection; and 3) an increase in the volume fractions of the inflammatory cells, especially monocytes and polymorphonuclear leukocytes, during the same period.

Animals↗
PubMed1984

A comparative study of filicidal and abusive mothers.

It is generally believed that some abusive parents if untreated eventually kill their children and "the murder of a child is the final chapter in his history of maltreatment." Yet only few authors have investigated the homicide of abused children. In this paper the authors report on a study of 8 filicidal and 52 abusive mothers referred to them by courts for pre-trial psychiatric evaluation. They found that there were significant differences between the two groups in that all (100%) of the filicidal women suffered from a major psychiatric illness before and at the time of committing the murder of their child while only 4 (7.7%) abusive mothers had a major psychiatric illness (x2 = 24.41, df = 1, p less than .001). They conclude from this study that the filicidal mothers are different from abusive mothers and that the risk of fatality as a complication of child abuse increases significantly when the mental illness is present in the mother. They point to the implications of their findings for child protection and intervention procedures and suggest that one should act very vigorously and take the child into protective custody when the mother is found to have a major psychiatric illness.

Adolescent↗
PubMed1984

A mathematical model for the cell age-dependent decline of creatine in human cell cells.

A mathematical model is proposed to describe the decline of creatine concentration in red blood cells during the course of cell aging. It is based on experimental data concerning two processes of creatine transport across the red cell membrane: a) an active transport, and b) exchange diffusion. The model corresponds well with data obtained from density-fractionated human red cells in normal steady-state erythropoiesis as well as in acutely and chronically activated erythropoiesis. Degradation of the carrier system for active transport is postulated to be the cause of the time course of decline of the cellular creatine concentration.

Creatine↗
PubMed1983

The diagnosis and frequency of X-linked conditions in a cohort of moderately retarded males with affected brothers.

An epidemiological study was carried out on the group of moderately retarded brothers (IQ, 30-55) identified by Turner and Turner [1974]. Of the original 58 sets of brothers, 54 sets (now 17 to 32 years old) were traced; another four sets (missed in the earlier survey) were added. Forty-five of the 58 pairs were diagnosed as having nonspecific X-linked mental retardation (MR) giving an overall frequency of 5.57 moderately retarded males/10,000 male births. In 12 of the 45 families, affected males had the fragile(X) and macroorchidism; six had macroorchidism alone, giving a frequency of 2.8 moderately retarded males with X-linked MR and macroorchidism +/- the fragile(X) per 10,000 males. Corresponding heterozygote frequencies are 7.34 and 3.65/10,000 females respectively. A new subgrouping of nonspecific X-linked mental retardation is described in six families: X-linked MR, macroorchidism without the fragile(X). Three other X-linked conditions were identified: in one family, the Coffin-Lowry syndrome, in another, Duchenne muscular dystrophy, and in two families X-linked MR and muscle atrophy. Half (56%) of the obligatory carriers of fra(X)-MR in this study were dull to mildly retarded. The mildly retarded heterozygotes had a significantly higher percentage of fra(X) expressing lymphocytes as compared to the intellectually normal heterozygotes. When the three types of nonspecific X-linked MR for which population frequencies were calculated were considered together, half of the obligatory carriers (46%) were dull or mildly retarded, thus confirming that this condition is a significant cause of mild intellectual handicap in females.

Adolescent↗
PubMed1983

[Behavior of creatine in red blood cells and in plasma of children with chronic kidney insufficiency].

The creatine concentration of red blood cells and plasma in 44 children with chronic renal failure was studied and found to be significantly higher than in healthy children of comparable age. The creatine concentrations of the 31 hemodialyzed children surpassed those of the 13 conservatively treated patients by 30%. A statistically significant correlation was demonstrated between the serum creatinine level and the creatine concentrations in red blood cells. During hemodialysis the plasma creatine concentration decreases by half and reaches the predialysis values within 42 h after the end of dialysis, whereas the creatine concentration of the red cells does not change during a 4-5-h hemodialysis. With increasing number of hemodialyses the creatine concentration of red cells rises, suggesting an improvement of erythropoiesis.

Adolescent↗
PubMed1983

Red cell creatine in term and preterm, adequate and small for gestational age newborns after normal pregnancy or risk conditions. I. Statistical analysis of creatine in various groups of newborns.

The red cell creatine concentration was determined in 174 newborns (cord blood) and in 50 healthy adults. Normal values for term adequate for gestational age newborns without intrauterine and perinatal risk (n = 53) were established to lie significantly above those for adults. Newborns after risk pregnancies had higher mean creatine concentrations than those born after uneventful gestation. Small for gestational age (SGA) infants proved to have the lowest creatine concentration of all newborn groups. The creatine values of our SGA children suggested that not more than 20% of them had chronic intrauterine hypoxia. It is concluded that red cell creatine at birth may serve to characterize in retrospect erythropoietic dynamics in cases of intrauterine growth retardation and intrauterine risk.

Creatine↗