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Biomedical subjects

J Ribera

Publications and source records attributed to J Ribera.

22 records · Page 2Linked to original sources
PubMed1988

Estimates of the prevalence of childhood maladjustment in a community survey in Puerto Rico. The use of combined measures.

A two-stage epidemiologic survey was carried out on a probability sample of the population aged 4 through 16 years in Puerto Rico. The survey used the Child Behavior Checklist as a screening instrument, and prevalence rates were estimated on the basis of clinical diagnoses and other measures provided by child psychiatrists during the second stage. Maladjustment was operationally defined through the use of combined measures, including DSM-III diagnosis and a scale of functional impairment. Data were provided on the demographic correlates of maladjustment and on the comorbidity of DSM-III diagnostic domains. The prevalence rates obtained vis-à-vis the availability of mental health services on the island reflected a major public health problem.

Adjustment Disorders↗
PubMed1987

Phylogenetic polymorphism on lectin binding to junctional and non-junctional basal lamina at the vertebrate neuromuscular junction.

The histochemical binding of seven fluoreceinated lectins was comparatively studied in muscular tissue from twenty three different animal species including mammalians, amphibians, avians and fishes. Special interest was taken in the exploration of the differential lectin-binding properties at the neuromuscular synapse. Binding to synaptic sites was demonstrated using lectins that recognizes N-acetylgalactosamine and among of them, Dolichus biflorus agglutinin (DBA), was the most specific. Nevertheless, DBA fails to stain endplates in the muscle from most of the avians and the fishes (including the Torpedo electric organ) indicating that a polymorphic distribution of glycoconjugates exist at the vertebrate neuromuscular junction. Other lectins such as Concanavalin A (ConA) or Wheat germ agglutinin (WGA), share a similar staining properties in all animals that we examined making an intense label over the complete muscle surface. Although the species-related polymorphism on lectin binding does not reveal a clear relationship with the evolutionary tree, they give an evidence on the chemical heterogeneity of molecules specifically concentrated at the neuromuscular junction.

Animals↗
PubMed1987

Receptors to agglutinin from Dolichus biflorus (DBA) at the synaptic basal lamina of rat neuromuscular junction. A histochemical study during development and denervation.

The binding of agglutinin from Dolichus biflorus (DBA) and other lectins (Concanavalin A, agglutinin from wheat germ and lectin from Bandeiraea simplicifolia) to synaptic and extrasynaptic portions of the basal lamina of muscle fibers, was studied with histochemical methods. In rat muscle, DBA-binding is specifically detected at the basal lamina of neuromuscular junction. However, long-term (6 months) denervated end-plate in adult rat muscle failed to bind DBA. During normal development, synaptic DBA receptors appear later than acetylcholine receptors or acetylcholinesterase at the rat neuromuscular junction. Generalized DBA-binding to motor end-plates is first visualized in 3-day-old rats, but section of sciatic nerve in 1-day-old rats prevents the appearance of synaptic DBA-binding on the leg end-plates. It is suggested, therefore, that the synaptic DBA receptors could be related to the postnatal stabilization of rat neuromuscular synapses.

Aging↗