[Orthodontic-prosthodontic treatment of posterior edentulousness].
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
R Garcia
Publications and source records attributed to R Garcia.
[Treatment of idiopathic necrosis of the femoral head by a vascularized fibular graft. Evaluation after 7 years experience].
Explore the source record for details and available documents.
Adult↗
Tactile/kinesthetic stimulation effects on preterm neonates.
Tactile/kinesthetic stimulation was given to 20 preterm neonates (mean gestational age, 31 weeks; mean birth weight, 1,280 g; mean time in neonatal intensive care unit, 20 days) during transitional ("grower") nursery care, and their growth, sleep-wake behavior, and Brazelton scale performance was compared with a group of 20 control neonates. The tactile/kinesthetic stimulation consisted of body stroking and passive movements of the limbs for three, 15-minute periods per day for a 10 days. The stimulated neonates averaged a 47% greater weight gain per day (mean 25 g v 17 g), were more active and alert during sleep/wake behavior observations, and showed more mature habituation, orientation, motor, and range of state behavior on the Brazelton scale than control infants. Finally, their hospital stay was 6 days shorter, yielding a cost savings of approximately $3,000 per infant. These data suggest that tactile/kinesthetic stimulation may be a cost effective way of facilitating growth and behavioral organization even in very small preterm neonates.
Body Weight↗
Partial characterization and solubilization of receptors for atrial natriuretic factor in rat glomeruli.
Specific receptors for atrial natriuretic factor (ANF) have been identified and solubilized in glomeruli from rat kidney. Radioiodinated synthetic ANF (Arg 101-Tyr 126) bound to a single class of high affinity (Kd 27 +/- 24 pM) sites with a density of 390 +/- 230 fmole/mg protein. The binding was time- and temperature-dependent, saturable and reversible. The ANF-receptor complex was not affected by angiotensin II, ACTH or vasopressin. Solubilization with 10 mM 3-[(3-cholamidopropyl)-dimethylammonio]- 1-propane sulfonate (CHAPS) slightly increased the affinity for ANF (Kd 5.0 +/- 3.3 pM) without affecting the density (250 +/- 110 fmole/mg protein). Similar results were found with 1% Triton X-100. ANF-related peptides interact generally in the same way with non-solubilized and solubilized receptors, indicating a fully preserved specificity of the receptors.
Adrenocorticotropic Hormone↗
Synthesis and biological activity of a linear fragment of the atrial natriuretic factor (ANF).
A linear fragment of the atrial natriuretic factor, ANF(106-125), unable to form an intramolecular cystine bridge, was synthesized by the solid-phase method. The fragment showed smooth muscle relaxant activity in the rabbit aorta and chick rectum assays, an inhibitory effect on aldosterone secretion from bovine adrenal zona glomerulosa cells, and had affinity for specific ANF receptors located in zona glomerulosa cell membranes. The potency of ANF(106-125) in these four assay systems was about two to three orders of magnitude lower than that of ANF(103-125) which contains the intact cyclic structure. The obtained results indicate that the disulfide linkage stabilizes the bioactive conformation of ANF peptides but is not an absolute requirement for biological activity.
Adrenal Cortex↗
Gluco- and mineralocorticoids may regulate the natriuretic effect and the synthesis and release of atrial natriuretic factor by the rat atria in vivo.
Adrenalectomy abolished the acute natriuretic effect of ANF which was partially restored to about 50% by combined therapy with gluco- and mineralocorticoids. It is suggested that the lack of effect of ANF may be due to a decreased renal vascular reactivity to the peptide in adrenalectomized animals. Simultaneous administration of Dexamethasone and Deoxycorticosterone acetate to adrenalectomized rats produced a marked increase in immunoreactive ANF in atrial tissue and plasma. The administration of NaCl to these animals produced a relatively lower concentration of atrial ANF and a further increase in plasma ANF. Our results suggest that glucocorticoids may regulate synthesis and release of ANF by the atria and mineralocorticoids may have a permissive role. Furthermore, the presence of steroids is necessary for the NaCl-stimulated ANF release.
Adrenalectomy↗
Identification of a biologically active circulating form of rat atrial natriuretic factor.
An atrial natriuretic peptide has been isolated from plasma of morphine treated rats by means of glass beads extraction, immunoaffinity chromatography, and reverse phase HPLC. 1.3 micrograms of immunoreactive material was obtained. The biological activity of this material was found comparable to that of ANF (Arg 101 - Tyr 126) on the inhibition of basal aldosterone secretion by rat adrenal zona glomerulosa cells and the displacement curve of iodinated ANF from ANF receptors in a mesenteric artery preparation. Gas phase amino acid sequencing indicated that it is related to ANF (Ser 99 - Tyr 126). These results suggest that the maturation of ANF may require a tryptic-like cleavage after a single Arg residue.
Adrenal Cortex↗
ANF (Arg 101--Tyr 126) is the peptide secreted by rat atrial cardiocytes in culture.
The atrial natriuretic factor (ANF) secreted from rat cardiocytes in culture was purified and characterized. The purification procedure involves extraction of ANF by activated Vycor glass, followed by HPLC on C18 mu Bondapak and Vydac columns. The detection of ANF in column eluates was performed by a simple and sensitive radioimmunoassay. The amino acid composition and N-terminal amino acid sequencing appeared to be identical to the Arg 101 - Tyr 126 peptide. The isolated ANF showed biological activity, inhibiting basal and ACTH-stimulating aldosterone secretion from rat zona glomerulosa cells with the same potency as the synthetic peptide.
Adrenal Glands↗
Effect of different anesthetics on immunoreactive atrial natriuretic factor concentrations in rat plasma.
The effect of different conditions of blood withdrawal and use of different anesthetics on immunoreactive atrial natriuretic factor (IR-ANF) concentrations in plasma was studied in rats. The concentration of IR-ANF in plasma from jugular vein of non-anesthetized conscious rats, cannulated either 24 hr before blood withdrawal was 93.9 +/- 17.1 pg/ml (n = 30); and 48 hr: 81.9 +/- 11.5 pg/ml (n = 29). Immobilization stress (4 hr) increased IR-ANF concentration: 248.0 +/- 80.2 pg/ml (n = 5). Anesthesia by morphine, diethyl-ether, chloral hydrate and ketamine chlorhydrate increased IR-ANF concentrations to 2,443.0 +/- 281.2 pg/ml (n = 24), 806.1 +/- 74.6 pg/ml (n = 64), 224.0 +/- 81.4 pg/ml (n = 20), and 195.0 +/- 20.3 pg/ml (n = 51), respectively. IR-ANF in plasma of sodium-pentobarbital and urethane anesthetized rats was 59.2 +/- 6.7 pg/ml (n = 10) and 42.6 +/- 8.1 pg/ml (n = 8), respectively. These changes in IR-ANF evoked by different types of anesthetics and different conditions of blood withdrawal have to be taken into consideration during studies on the physiopathological role of atrial natriuretic factor.
Anesthetics↗
Immunoreactive atrial natriuretic factor (IR-ANF) in human plasma.
A direct radioimmunoassay for ANF in human plasma was developed. A synthetic alpha-human atrial peptide (Ser 99-Tyr 126) was used for preparation of the iodinated tracer and the standards. The sensitivity of the method is 1.9 pg/ml. Concentration of immunoreactive ANF (IR-ANF) in plasma of 59 clinically normal subjects was 65.3 +/- 2.5 pg/ml (mean +/- SE). In two patients who underwent atrial pacing an increase of about 100 percent in circulating IR-ANF was observed. IR-ANF was extracted from human plasma by Vycor glass and purified by HPLC. The main immunoreactive isolated peak contained a low molecular weight peptide.
Atrial Natriuretic Factor↗
Changes of regional blood flow induced by atrial natriuretic factor (ANF) in conscious rats.
The effect of synthetic atrial natriuretic factor (ANF 101-126) has been studied on regional blood flow distribution. Microspheres (15 +/- 3 microns), labelled with either 113Sn or 57Co, were injected through an intraventricular cannula into conscious rats while a reference blood sample was withdrawn. Two minutes after the first microspheres injection either ANF or NaCl were injected. Five minutes later, the second microspheres injection was administered, and after two minutes the animals were sacrificed, and several tissues removed and counted. Percent of flow distribution, cardiac output and tissue blood flow were calculated by standard formulas. ANF produced a significant increase in absolute blood flow in lungs, heart, spleen, kidneys and testes. Total renal blood flow and total splanchnic blood flow were also increased in ANF-injected animals. No significant changes were observed in cardiac output. It is suggested that the natriuretic and hypotensive responses to ANF in vivo may be, at least partially, explained by its hemodynamic effects.
Animals↗
Structure-activity relationships of atrial natriuretic factor (ANF). II. Effect of chain-length modifications on vascular reactivity.
The effect of the length of ANF peptides on the inhibition of the norepinephrine-induced contraction was studied. Starting from the 26 residues ANF (Arg101-Tyr126), shorter N- and/or C-terminal fragments were produced, either by N-terminal chemical cleavage or C-terminal enzymatic digestion of ANF or both respectively. The N-terminal removal of Arg101 did not modify the inhibitory response. Further N-terminal truncation up to des-Arg101-Arg102-Ser103-Ser104 ANF still produced a marked inhibitory effect on norepinephrine. In contrast C-terminal cleavage had a much more pronounced effect. Since des-Tyr126 ANF, des-Arg125-Tyr126 ANF and des-Phe124-Arg125-Tyr126 ANF exhibit much lower activities than the parent ANF. Finally, when the 5 residues C-terminal to Cys121 are removed, the resulting molecule is almost inactive. These data indicate that the C-terminal segment of ANF may modulate the binding of ANF to its receptor(s). Relatively, the N-terminal region seems to be much less important.
Animals↗
Radioautographic localization of 125I-atrial natriuretic factor (ANF) in rat tissues.
Rats were injected either with synthetic 125I-Arg 101-Tyr 126 atrial natriuretic factor (ANF) or with 125I-ANF together with an excess of cold Arg 101-Tyr 126 ANF. Binding sites in various tissues were accepted depending on two criteria: displacement of radioactivity by cold ANF and absence of localization of silver grains on putative target cells in the presence of cold ANF. Binding sites were localized on zona glomerulosa cells and on adrenergic and noradrenergic cells of adrenal medulla, on hepatocytes, on the base of mature epithelial cells of villi in the small intestine, on smooth muscle cells of the muscularis layer of the colon and on the base of epithelial cells of the ciliary bodies. In addition, binding sites were localized in the vasculature of kidney, adrenal cortex, lung and liver. Binding sites were particularly numerous on renal glomerular endothelial cells. These results indicate that ANF may have important hemodynamic effects in kidney, lung, liver and adrenal cortex, may regulate water and ion transport in small intestine and ciliary bodies and may have metabolic effects in the liver. The presence of binding sites on the zona glomerulosa is in agreement with the important inhibitory effect of the peptide on aldosterone secretion.
Adrenal Glands↗
Influence of E. coli endotoxin on ACTH induced adrenal cell steroidogenesis.
The effect of endotoxin (lipopolysaccharide from E. coli) on isolated adrenocortical cells was examined. Lipopolysaccharide decreased the ACTH-induced steroidogenesis. This effect was shown by all corticotropin concentrations studied, and the longer the incubation time, the higher the effect produced. The rate of decrease of ACTH-induced steroidogenesis was dependent on the concentration of lipopolysaccharide in the medium. Binding of [125I]ACTH to adrenocortical cells was modified by lipopolysaccharide; this modification was related to a decrease of the ACTH-induced steroidogenesis. This effect supports the hypothesis of a direct interaction between lipopolysaccharide and the cell membrane with a concomitant distortion of the cell surface affecting the ACTH receptor sites of their environment. [14C]Lipopolysaccharide binds to isolated adrenocortical cells. Binding specificity was investigated by competitive experiments in the presence of various types of endotoxins, polypeptide hormones and proteins. Unlabelled lipopolysaccharide from the same bacterial strain and isolated under identical conditions than the labelled lipopolysaccharide exerted the strongest inhibitory activity. Unlabelled lipopolysaccharide of various strains different from that originating the labelled lipopolysaccharide exerted the less displacement. It would imply a certain kind of specificity but the decrease in the binding of lipopolysaccharide produced by ACTH and glucagon suggests the existence of non-specific interactions between lipopolysaccharide and cell membrane.
Adrenal Cortex↗
Effects of vagotomy on satiety induced by gastrointestinal hormones in the rat.
Cholecystokinin, bombesin and pancreatic polypeptide are all reported to induce satiety in rodents. To test the hypothesis that cholecystokinin and bombesin induce satiety through release of pancreatic polypeptide, we compared the satiety inducing properties of each peptide in rats trained to eat a liquid diet (Magnacal). Studies were repeated after transabdominal truncal vagotomy (n = 8) or sham operation (n = 8). Peptides were given by intraperitoneal injection, and the volume of Magnacal ingested over a 2 hr period measured. After the injection of saline, unoperated rats (n = 16) ingested 30 +/- 2.3 ml of Magnacal. Caerulein (9 nmol/kg) and bombesin (27 nmol/kg) significantly inhibited food intake to 8 +/- 2.5 ml and 20 +/- 2.1 ml respectively. In contrast pancreatic polypeptide (27 nmol/kg) had no significant effect on food intake. Both caerulein and bombesin retained the ability to reduce food intake after vagotomy although the effects of caerulein were somewhat blunted. No significant changes in serum pancreatic poly peptide concentrations were observed after either the caerulein or bombesin injection. As both peptides release pancreatic polypeptide in higher mammals, species differences in release mechanisms appear to exist. We would conclude that caerulein and bombesin induced satiety is independent of pancreatic polypeptide release and that the weight loss induced by pancreatic polypeptide in obese rodents is unlikely to be due to induction of satiety.
Animals↗
Ectopic meningioma of the nose and paranasal sinuses (report of a case).
Explore the source record for details and available documents.
Aged↗
Effect of natural and synthetic atrial natriuretic factor on arterial blood pressure, natriuresis and cyclic GMP excretion in spontaneously hypertensive rats.
The differential effects of extracted and synthetic atrial natriuretic factor (ANF) on arterial blood pressure, natriuresis, and cyclic GMP excretion were studied in normotensive (WKY) and spontaneously hypertensive (SHR and SHRSP) rats. Atrial extracts or synthetic (101-126)-ANF decreased arterial blood pressure in all tested animals, but the blood pressure-lowering effect was more pronounced in hypertensive than in normotensive rats. ANF-induced diuresis and natriuresis were two- to three-fold higher in the hypertensive groups. However, a several-fold increase in total urinary cyclic GMP level after the infusion of ANF was essentially equal in the three groups. Our data suggest that acute infusion of ANF reveals a defect of sodium and water handling in SHR. It is possible that this defect is located at the distal nephron, and is made apparent by the action of ANF on glomeruli via a cyclic GMP-induced vascular effect.
Animals↗