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Biomedical subjects

I Serra

Publications and source records attributed to I Serra.

At least 37 records · Page 2Linked to original sources
PubMed1988

Cytodifferentiation of mouse visceral endoderm: study with a teratocarcinoma antiserum.

In this work we separated homogeneous embryoid bodies (EB); this population is composed of only endodermal vesicles of a visceral type. These EB were used to immunize rabbits. After absorption, the antisera were analyzed immunohistochemically in sections of 7.5- and 9-day-old mouse embryos, which showed a selective reaction to visceral endoderm. The cytodifferentiation of the visceral endoderm was studied.

Animals↗
PubMed1986

Nuclear and mitochondrial DNA synthesis and energy metabolism in primary rat glial cell cultures.

DNA synthesis in nuclei and mitochondria purified from serum-supplemented rat glial cell cultures at different days after plating was studied. Furthermore in mitochondria, some enzymatic activities related to energy transduction (citrate synthase, malate dehydrogenase, total NADH-cytochrome c reductase, cytochrome oxidase and glutamate dehydrogenase) were measured. For DNA labeling [methyl-3H]thymidine was added to the culture medium at different days after plating. During the culture times studied the specific activity of total, nuclear, and mitochondrial DNA decreased from 8 days in vitro (DIV) to 21 DIV and increased at 30 DIV. The specific activity of nuclear DNA was always higher than that of mitochondrial DNA. The specific activity of the above mentioned mitochondrial enzymes increased from 8 DIV up to 21 DIV and decreased at 30 DIV, suggesting a relationship between the energy metabolism and the differentiation of glial cells in culture.

Animals↗
PubMed1986

The combined composite pectoralis major and minor osteomusculocutaneous flap.

Combining the pectoralis major and minor into a single flap can provide a much longer vascularized segment of bony rib than if the pectoralis major is used alone. This result is possible because of the periosteal vessels emerging from the origins of the pectoralis major and minor. Both muscular attachments are contiguous. The particular characteristics of this flap make it useful for reconstructive surgery of the head and neck when transposed locally, or for other distant regions when microsurgery is attempted.

Bone Transplantation↗
PubMed1986

Acetylation and phosphorylation of histones and nonhistone chromosomal proteins in neuronal and glial nuclei purified from cerebral hemispheres of developing rat brain.

The processes of acetylation and phosphorylation of histones and nonhistone proteins (NHPs) in neuronal and glial nuclei purified from cerebral hemispheres of rats at 1, 10, and 30 days of age were investigated. Purified neuronal and glial nuclei were incubated in the presence of [3H]acetyl-CoA and of [gamma-32P]ATP. Histones and NHPs were extracted and fractionated by gel electrophoresis. Densitometric and radioactive patterns were obtained. The results showed an increase of acetylation and phosphorylation from 1 to 10 and 30 days of age in both neuronal and glial nuclei in almost all histone and NHP fractions. Among the histones, the H3 fraction was always more labeled than the other fractions and showed the most remarkable differences during postnatal development. In the NHP fractions, the increase in acetylation from 1 to 10 and 30 days of age was more evident in the low-molecular-weight region of neuronal nuclei than in the corresponding fraction of glial nuclei. The appearance of highly phosphorylated proteins (70,000-90,000 daltons)--absent at 1 day, appearing at 10 days, and more evident at 30 days of age--was observed in both neuronal and glial nuclei.

Acetylation↗
PubMed1986

[Pyometra].

Explore the source record for details and available documents.

Aged↗
PubMed1985

Effect of hypothyroidism on the biogenesis of free mitochondria in the cerebral hemispheres and in cerebellum of rat during postnatal development.

The effect of propylthiouracil-induced neonatal hypothyroidism on some aspects of the biogenesis of free (non-synaptosomal) mitochondria in the cerebral hemispheres and in the cerebellum of developing rat has been studied. The results obtained show that in hypothyroid rats mitochondrial DNA synthesis is delayed, mitochondrial RNA synthesis is not affected and cytochrome aa3 content of mitochondria is lower than in controls. Furthermore ultrathin sections of 14- and 21-day old hypothyroid rat cerebella show mitochondria with an altered ultrastructural organization and large intracristal spaces.

Animals↗
PubMed1985

Effect of hypothyroidism on the labeling of the various RNA species in developing rat brain.

The effect of hypothyroidism on the vitro incorporation of [3H]uridine into different RNA species in tissue slices of rat cerebral hemispheres at 5, 10, 15, and 21 days of age has been investigated. Gel electrophoresis analysis of total, nuclear and microsomal RNA was also accomplished. The results obtained indicate that RNA labeling is differently influenced by hypothyroidism at the various ages examined. RNA labeling is not significantly affected at 5 days of age while at later ages and especially at 21 days it is higher in hypothyroid rats compared to the controls. Moreover distinct differences at the various ages in the transport of newly synthesized RNA from the nucleus to the cytoplasm in the two groups of animals were found. These results are in agreement with the hypothesis that thyroid hormone deficiency causes a delay of the processes of cell proliferation and differentiation in developing rat brain.

Age Factors↗
PubMed1985

Methylation of chromosomal proteins in neuronal and glial nuclei purified from cerebral hemispheres of rat during postnatal development.

The process of methylation of chromosomal proteins [histones and nonhistone proteins (NHP)] in neuronal and glial cell nuclei obtained from cerebral hemispheres of rats at 1, 10, and 30 days of age was investigated. Purified neuronal and glial nuclei were incubated in the presence of S-adenosyl[methyl-3H]methionine. Histone and NHPs were extracted and fractionated by polyacrylamide gel electrophoresis. The results obtained indicate remarkable differences in the process of methylation of histones and NHPs between neuronal and glial nuclei, especially during the first period of postnatal development. In both nuclear populations the histone fraction H3 was labeled to a greater degree than the other fractions and showed the major changes during postnatal development. The densitometric and radioactive patterns of NHPs show considerable changes in the two nuclear populations at the various ages examined. The main difference between neuronal and glial nuclei consists in the intense methylation of proteins with a molecular weight of approximately 100,000, which are present in neuronal nuclei and virtually absent in glial ones. The results obtained may be correlated with the different chromatin structures of neuronal and glial nuclei and with the patterns of maturation and differentiation of neuronal and glial cells during postnatal development.

Age Factors↗
PubMed1984

RNA synthesis in neuronal and glial cell nuclei from rat cerebral hemispheres during early postnatal development.

RNA synthesis in rat cerebral hemispheres at 1, 5, and 10 days of age and the relative contribution brought by neuronal and glial nuclei to RNA synthesis was investigated. The experiments were carried out both in vivo (by i.p. injection of [3H]uridine) and in vitro (either by incubation of tissue slices with [3H]uridine or by determination of RNA polymerase activities). The labeling of RNA decreases from 1 to 10 days of age both in vivo and in vitro; the decrease is of the same extent in neuronal and glial nuclei. RNA polymerase activity Mg2+-dependent does not change significantly from 1 to 10 days of age either in total, in neuronal, or in glial nuclei, whereas the Mn2+-dependent activity increases significantly over the same developmental period studied. The significance of RNA polymerase assay as an index of in vivo RNA synthesis is discussed.

Animals↗
PubMed1983

Effect of undernutrition on some enzymes of purine metabolism in different regions of developing rat brain.

The effect of undernutrition on the activity of some enzymes involved in purine metabolism, ie, adenosine aminohydrolase, adenylate aminohydrolase, and inosine phosphorylase in cerebral hemispheres, cerebellum, and brain stem of rats at different days of postnatal development was studied. Adenosine aminohydrolase, adenylate aminohydrolase, and inosine phosphorylase were assayed by radiochemical methods which involve the measurement of the radioactive products formed, ie, inosine, IMP, and hypoxanthine, respectively. The results obtained indicate that undernutrition affects the activity of the enzymes which control the concentration of purine nucleotides to a different degree in the three brain regions examined.

AMP Deaminase↗
PubMed1983

Effect of undernutrition on some enzymes involved in the salvage pathway of purine nucleotides in different regions of developing rat brain.

The effect of undernutrition on the activity of two key enzymes of purine salvage pathway, namely hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and adenine phosphoribosyltransferase (APRTase), in cerebral hemispheres, cerebellum and brain stem of rats at different days of postnatal development was studied. The activity of HGPRTase and of APRTase is significantly lower in all brain regions of undernourished animals at 5 days after birth; between 10 and 15 days of age there is a recovery of the enzymatic activity which is particularly evident in the cerebellum. Successively both enzymatic activities decrease reaching at 30 days of age values quite similar to those of controls. These results indicate that undernutrition during fetal and postnatal development, impairs and delays the activity of the enzymes of purine salvage pathway.

Adenine Phosphoribosyltransferase↗