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Biomedical subjects

M Celio

Publications and source records attributed to M Celio.

18 recordsLinked to original sources

Early maturation as a risk factor for aggression and delinquency in adolescent girls: A review.

Early physical maturation has long been considered a risk factor for the development of delinquent girls. The basis of this relationship has not been fully explored or understood. This review summarises the current literature and research on early physical maturation in adolescent females and places it within a developmental perspective. The process of early physical maturation is also placed within a biopsychosocial model so that risk and protective factors arising from the biological, social, family, education and peer environments can be ascertained. A complex model of maturation and environmental-social interaction is constructed and currently supported by research, but it is clear that a great deal of further work is necessary to fully understand this process.

Adolescent↗

Deficiency in parvalbumin increases fatigue resistance in fast-twitch muscle and upregulates mitochondria.

The soluble Ca2+-binding protein parvalbumin (PV) is expressed at high levels in fast-twitch muscles of mice. Deficiency of PV in knockout mice (PV -/-) slows down the speed of twitch relaxation, while maximum force generated during tetanic contraction is unaltered. We observed that PV-deficient fast-twitch muscles were significantly more resistant to fatigue than were the wild type. Thus components involved in Ca2+ homeostasis during the contraction-relaxation cycle were analyzed. No upregulation of another cytosolic Ca2+-binding protein was found. Mitochondria are thought to play a physiological role during muscle relaxation and were thus analyzed. The fractional volume of mitochondria in the fast-twitch muscle extensor digitorum longus (EDL) was almost doubled in PV -/- mice, and this was reflected in an increase of cytochrome c oxidase. A faster removal of intracellular Ca2+ concentration ([Ca2+]i) 200-700 ms after fast-twitch muscle stimulation observed in PV -/- muscles supports the role for mitochondria in late [Ca2+]i removal. The present results also show a significant increase of the density of capillaries in EDL muscles of PV -/- mice. Thus alterations in the dynamics of Ca2+ transients detected in fast-twitch muscles of PV -/- mice might be linked to the increase in mitochondria volume and capillary density, which contribute to the greater fatigue resistance of these muscles.

Animals↗

The calcium-binding protein calretinin-22k, an alternative splicing product of the calretinin gene is expressed in several colon adeno carcinoma cell lines.

An alternatively spliced mRNA for the calcium-binding protein calretinin (CR) is present in the colon adenocarcinoma cell line WiDr. As a consequence of a frame shift, the resulting protein, calretinin-22k (CR-22k), consists of the first 178 amino acids of calretinin followed by a carboxy-terminal peptide of 14 amino acids that is not present in full-length calretinin. Antibodies specific for this C-terminal region have been generated by 2 different methods. A peptide corresponding to the specific C-terminal region of CR-22k was either chemically synthesized and coupled to a carrier protein or was expressed in Escherichia coli as a carboxyterminal fusion to a carrier protein applying recombinant techniques. Both antisera produced in rabbits were tested in Western blots and immuno-histochemical experiments. The antisera recognized human recombinant CR-22k overexpressed in E. coli, but not fulllength calretinin and stained fixed WiDr cells. The presence of CR-22k was also confirmed in the colon cell lines CO115/3 in which mRNA coding for CR-22k mRNA coding for CR-22k mRNA is present as well as in the lines COLO205 and LS-180, all of which also express full-length calretinin. Although the intracellular distribution of CR-22k and CR are similar as evidenced by immunohistochemical stainings, CR-22k is preferentially localized in the nucleus in the cell lines LS-180 and Co115/3 suggesting potentially different roles for the two proteins.

Adenocarcinoma↗

Streptococcus mitis cell walls and lipopolysaccharide induce lethality in D-galactosamine-sensitized mice by a tumor necrosis factor-dependent pathway.

Purified cells walls of Streptococcus mitis induced tumor necrosis factor in vitro in whole blood of both lipopolysaccharide (LPS)-sensitive OF1 and LPS-resistant C3H/HeJ mice. They were as effective as heat-killed bacteria in inducing death in both strains of mice sensitized with D-galactosamine. Lethality was suppressed by anti-tumor necrosis factor antibodies. The histopathophysiological findings in mice after challenge with LPS or gram-positive cell walls were indistinguishable.

Animals↗

Effects of growth hormone and estrogen on rat angiotensinogen quantified by an enzyme linked immunosorbent assay.

An enzyme linked immunosorbent assay for rat angiotensinogen was developed based on one monoclonal antibody with high affinity for angiotensinogen and des-angiotensin 1-angiotensinogen and rabbit polyclonal antibodies for angiotensinogen was developed. Serum levels of angiotensinogen were lower in female than in male rats but increased significantly after hypophysectomy. Estrogen substitution after hypophysectomy had no further stimulatory or inhibitory influence. In hypophysectomized animals continuous and intermittent growth hormone administration had clearly different effects. The results indicate that the sexually dimorphic secretion of growth hormone is involved in the regulation of circulating angiotensinogen concentrations in the rat.

Angiotensinogen↗

Substance P--positive structures in rat spinal cord--a longitudinal bundle ventral to the central canal.

Using the immunoperoxidase method, the distribution of substance P (SP)-positive structures was studied in different levels of the rat spinal cord. In general, the density of SP-positive sites proved to be higher in lumbar and sacral than in cervical and thoracic segments. In transverse sections, the density was highest in lamina I, and decreased in dorso-ventral direction. Following colchicine injection into the spinal cord, many SP-positive cell bodies could be visualized in the dorsal and lateral horn as well as in the lateral spinal nucleus. In front of the central canal, an SP-immunoreactive longitudinal bundle (FLCV) showing close relation to the ependyma, extends throughout the whole length of the spinal cord. This bundle, which also displays acetylcholinesterase activity, electronmicroscopically consists of thin myelinated and unmyelinated fibers, some of which containing numerous synaptic vesicles. SP-positive fibers penetrating between ependymal cells and abuting on the luminal surface of the central canal probably arise from the FLCV.

Acetylcholinesterase↗

Production and characterization of monoclonal antibodies to rat angiotensinogen.

Three stable monoclonal antibodies to rat angiotensinogen were obtained by fusing myeloma cells with spleen cells from Balb/c mice injected with pure rat angiotensinogen. They were screened by their binding to pure iodinated angiotensinogen and to insolubilized angiotensinogen in a solid phase assay. The titers of the three antibodies varied from 1/3500 to 1/35000, their dissociation constants from 2.5 X 10(-8) M to 3.8 X 10(-10) M, and the sensitivity of the assay ranged from 200 to 10 pmol of pure angiotensinogen. These monoclonal antibodies did not recognize either angiotensin peptides or angiotensinogen from other species, except for mouse angiotensinogen, which cross-reacted with the different antibodies from 0 to 25%. Rat cerebrospinal fluid angiotensinogen, plasma des-angiotensin I-angiotensinogen, and plasma angiotensinogen were equally recognized by these monoclonal antibodies. Contrary to what was observed for a polyclonal antiserum, the monoclonal antibodies failed to inhibit the renin-angiotensinogen reaction in vitro.

Angiotensinogen↗