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Biomedical subjects

N Ricci

Publications and source records attributed to N Ricci.

At least 37 records · Page 2Linked to original sources
PubMed1983

Neurological and psychological development of low-risk preterm infants in the first year of life.

Twenty-four selected low-risk preterm and 10 full-term infants were followed in a prospective study of the evolution of neurological signs in the first year of life and to consider the prognostic value of transient neurological abnormalities in relation to learning disabilities at school age. We report the results of the assessments made during the first 12 months. The assessment at 3, 6, 9 and 12 months was made using the Amiel-Tison neurological schedule and the Griffiths developmental scale. A high percentage of our low-risk premature infants (69% of 37-34 weeks gestational age and 75% of 33-27 weeks gestational age group) showed transient neurological anomalies, whereas no major neurological sequelae, i.e., cerebral palsies or mental impairment, were found. Moreover, in our series, the syndrome of transient dystonia associated with low birth weight, already described by other authors in samples not selected for risk, was not observed. The psychological development of all our infants was within normal limits at every assessment. Nevertheless, a significantly decreased performance at the sixth month in both preterm groups, particularly in the group of low gestational age, was found, and its significance will be clarified by further follow-up studies of early school age.

Developmental Disabilities↗
PubMed1976

Cell surface control in Blepharisma intermedium (Protozoa Ciliata). Blocking of gamone II-induced homotypic interacting ligands.

PHA, Con-A, or anti-tubulin antibodies inhibit homotypic pair formation, in B, intermedium mating type-I cells in the presence of suboptimal concentrations of gamone II. The inhibition is dependent on the dose of gamone added; the structural conformation and the relative concentration of the inhibitor; and the time of addition of the inhibitor. The block can be selectively prevented by competitive inhibitors of each ligand. The receptors for the inhibitors are distinctive and there is no cross-reaction between the ligands. It is concluded that ligand binding and subsequent receptor-ligand aggregation must induce a change within the cell-surface membrane, which distorts the distribution and/or affects an optimal conformational aspect of a specific membrane-receptor system for the gamon, a prerequisite for cell pair formation.

Acetylgalactosamine↗
PubMed1975

Ring chromosomes and leukaemia.

The observation of 2 leukaemic patients with ring chromosomes, and their comparison with a few previously reported cases, suggests a close association between this rare chromosomal abnormality and erythroleukaemia and indicate a poor prognostic significance of this finding.

Aged↗
PubMed1975

Conjugation in Oxytricha bifaria: cell interaction.

As a model of cell interaction, the mating process of Oxytricha bifaria has been investigated. Mating involves several distinct and sterotyped stages, each lasting a determined time, and ending with the formation of firmly united pairs. A "waiting period" intervenes between the mixture of complimentary mating types and the onset of cell interaction. A proper starvation shortens the waiting period (25 min vs 120 min). Treatment of properly starved cells with heterologous cell-free fluid further reduces the waiting period. Certain enzyme treatments (pronase, trypsin and lipase) dramatically increase the waiting period in both washed enzyme-treated cells and in unwashed cells. Trypsin inhibits the first two stages of the mating process, while lipase inhibits membrane fusion between mates.

Cell Division↗
PubMed1975

Observations on specific giemsa staining of the Y and on selective oil destaining of the chromosomes.

The human Y chromosome can be differentially stained with Giemsa using simple procedures. This phenomenon is strikingly to that observed with quinacrine fluorescence. The specific Giemsa-Y stain may be selectively removed by the action of an oil. The same oil, under certain conditions, selectively removes Giemsa stain from all chromosomes, resulting in R- and T-banding patterns. These bands, which are obtained through subtraction of dye from Giemsa-stained chromosomes, allow slides to be further processed.

Heterochromatin↗