Inhibition of the noradrenaline-induced adenyl cyclase stimulation by augmented alpha-adrenergic response in subcutaneous adipose tissue from hypothyroid subjects.
Explore the source record for details and available documents.
Adenylyl Cyclases↗
Biomedical subjects
V Grill
Publications and source records attributed to V Grill.
Effect of composition of mixed meals--low- versus high-carbohydrate content--on insulin, glucagon, and somatostatin release in healthy humans and in patients with NIDDM.
Effects of a low-carbohydrate high-fat meal (LCM) versus a high-carbohydrate low-fat meal (HCM) on insulin, glucagon, and somatostatin release in nonobese healthy volunteers and in subjects with mild non-insulin-dependent diabetes mellitus (NIDDM) were compared. The meals were isocaloric. In the LCM, 26% of energy was supplied by carbohydrate, 51% by fat, and 23% by protein, whereas corresponding figures for HCM were 62, 22, and 16%. Hormonal responses were expressed as incremental areas over baseline. In healthy volunteers the HCM had a significantly greater effect on the insulin response than did the LCM. In contrast, in the diabetic group the insulin response to HCM was markedly impaired and was of the same magnitude as that to LCM. Glucagon release was significantly augmented after LCM in the nondiabetic as well as in the diabetic group, despite a pronounced and concomitant hyperglycemia in the latter. Moreover, HCM tended to stimulate glucagon release but only in the diabetic subjects. LCM and HCM induced a significant and sustained elevation of somatostatin levels in both groups; these responses were not significantly influenced by glucose tolerance or composition of meal. In conclusion, the present study suggests that at least two islet dysfunctions--decreased insulin response and enhanced glucagon release--characterize mild NIDDM. With a high-carbohydrate meal, a severe impairment of insulin secretion and a slight paradoxical glucagon release are observed. With a low-carbohydrate fat-rich meal, beta-cell responsiveness seems to be intact, but alpha-cell secretion is enhanced.
Adult↗
Immunocytochemical expression of protein kinase C isoenzymes alpha, delta, epsilon and zeta in differentiating chick chondrocytes in vitro.
In our previous work we have investigated the expression of the serine-threonine kinase protein kinase C (PKC) in the vertebral column of mouse foetuses. In the present work we would verify the expression of four PKC-isoenzymes (alpha, delta, epsilon, zeta) in two distinct phases of the chondrogenesis and the endochondral osteogenesis in vitro. We performed primary cultures of chondrocytes collected from tibiae of 6-day old chick embryos. This cells were cultured for 20 days and than collected on coverslips (stage 1 culture). Other cells of the stage 1 were undergone further differentiation towards the phenotype of osteoblast-like cells (stage 2 culture), in accord to the protocol of Descalzi Cancedda et al. (1992). In stage 1 culture, PKC-epsilon was the most expressed isoform, whereas PKC-alpha exhibited the least intense positivity. In stage 2 culture, PKC-alpha was the most expressed isoform, whereas a marked decrease of PKC-epsilon expression was detected compared to stage 1. No relevant differences were evidenced as regards,the expression of PKC-zeta between the two considered cell culture stages. On these bases, it could be reasonable that these PKC-isoenzymes may be involved at different levels in chondrocytes differentiation as well as in the endochondral ossification process.
Animals↗
In vitro evaluation of the biocompatibility of dental alloys: fibronectin expression patterns and relationships to cellular proliferation rates.
OBJECTIVE: This short-term (72- to 96-hour) in vitro study on fibroblasts evaluated the biocompatibility of 3 single-phase dental alloys by determining cellular proliferation rates and the expression of a glycoprotein, fibronectin, which is involved in cellular adhesion processes. METHOD AND MATERIALS: Flow 2002 fibroblasts were cultured together with 3 single-phase dental alloys of different composition. Proliferation rates were determined by 5-bromodeoxyuridine incorporation. Fibronectin expression was determined by indirect immunofluorescence. RESULTS: At 72 hours, cells cultured with the alloy containing the lowest amount of noble elements (gold, platinum, and palladium) and the highest amount of silver exhibited significantly less proliferation than did controls. At 96 hours, only cultures with the alloy containing the greatest amount of noble elements behaved in a way similar to controls. Fibronectin organization in fibrils and in focal adhesions was correlated to higher cellular proliferation rates. CONCLUSION: Fibronectin organization could be a useful tool to determine the biocompatibility of dental alloys. Among the noble elements, palladium by itself exhibits very good biocompatibility. These indications could be useful for practitioners in the choice of the best alloy for specific clinical applications.
Biocompatible Materials↗
Further considerations on the intranuclear distribution of HMGI/Y proteins.
We have investigated the intranuclear distribution of High-mobility group proteins I/Y by means of immunofluorescent staining employing a variety of cell lines. Confocal scanning laser microscopy analysis revealed that High-mobility group proteins I/Y are present in an intranuclear fibrogranular network and mitotic chromosomes. In Caski, C4I, Flow 2002, and K562 cell lines, High-mobility group proteins I/Y were absent from nucleoli, whereas in HeLa cells they were present in this nuclear domain. Double immunolabeling studies showed that High-mobility group proteins I/Y co-localize with other key nuclear components such as NuMA, SC-35, and TAF(II)70. Nuclear reactivity for High-mobility group proteins I/Y dramatically decreased in apoptotic nuclei of HL-60 human leukemia cells. Our morphological data correlate well with previous biochemical and functional findings obtained by other investigators, who have demonstrated multiple roles for this class of polypeptides. However, they point to the likelihood that High-mobility group proteins I/Y are involved in as yet unidentified functions, most likely in the speckle domains of the nucleus. They also show that conceivably these proteins are also involved in apoptosis.
Antigens, Nuclear↗
Morphological features and measurements in a human fetus with karyotype 69, XXX: comparison with fetuses of the same CRL, without chromosomal anomalies.
A triploid fetus (karyotype 69, XXX) with crown-rump length (CRL) 94 mm, presenting micro- and retrognathia, low-set ears and crooked feet, was cleared and double-stained with alizarin red S and alcian blue for detecting the ossification patterns in the vertebral column, ribs, ischium, limbs, and face. Longitudinal measurements of some long bones in the upper (humerus, ulna, radius) and lower (femur, tibia, fibula) limb were taken. The values of both the total length (TL) and the ossified part (OL) of each long bone, as well as the OL/TL per cent ratio were considered. Reference points were located on the mandible, i.e. condylar process (Pcl), coronoid process (Pco), gnathion (GN), gonion (GO), superior symphyseal point (SSP) for measuring linear dimensions. Since the aim of this work was to assess the influence of triploidy 69, XXX the skeletal development and growth patterns, all values obtained in the examined specimen were related with those relative to a group of fetuses, without any detectable malformation and chromosomal anomalies, with a CRL mean value of 93 mm. Results evidenced that the triploid fetus presented growth restriction and that the vertebral centra ossification and the mandibular development were much delayed with the normal ossification patterns.
Alcian Blue↗
Protein kinase C (PKC) isoenzymes exhibit specific expression in the vertebral column of human fetuses.
Recent studies have shown that protein kinase C (PKC) plays a pivotal role in many cellular functions, i.e. cell proliferation and differentiation, exocytosis, ion-exchange regulation, hormone and neurotransmitter release, programmed cell death. Up to now the tissue and organ distribution of PKC isoenzymes have been studied in various mammalian adults and it has been suggested that each of them could play a specific role in the regulation of various cellular functions. However, few works have been performed on the expression of the enzyme in actively proliferating and differentiating tissues, i.e. during embryonal and fetal developmental stages. In the present study we have performed an immunohistochemical analysis by using polyclonal antibodies in order to verify the distribution of nine PKC isoenzymes in the vertebral column of human fetuses in a key period (8th developmental week), when the most relevant chondrogenetic and osteogenetic processes occur. The detection of the various PKC isoenzymes and their different distribution in the vertebral bodies and in the intervertebral spaces lead to speculate that the appearance, localization and activation of PKC isoforms in chondrocytes might depend on the stage of chondrogenesis and suggest that cartilage and developing bone represent an appropriate cell system to understand the mechanism of signal transduction, which involves the enzyme.
Cartilage↗
Histochemical and ultrastructural investigation on the cytotypes in the mouse Harderian gland.
The presence of melatonin and other biogenic indoleamines in the Harderian gland has been proposed by various authors. In the present work we would have investigated which of the cytotypes of the mouse Harderian gland might be involved in melatonin turnover. For this aim we employed the osmium tetroxide-zinc iodide (ZIO) histochemical technique that has been proposed useful to identify indole monoamines. Harderian glands of male, female and pregnant female mice were studied by light and transmission electron microscopy (TEM). Secretory type B cells were selectively stained by the ZIO-mixture, much more in female than male; type A cells were much more numerous than type B ones and never ZIO-positive. Ultrastructural examinations showed that type B cells contain numerous granules in the whole cytoplasm, in the perinuclear cisterna and around the cytoplasmic vacuoles and vesicles. Myoepithelial cells were sometimes found weakly ZIO-positive. Endothelial cells of capillary blood vessels presented ZIO-precipitates in the cytoplasm, as well as in the perinuclear cisterna. These data may suggest an uptake of melatonin from the blood stream and an involvement of type B secretory cells in melatonin catabolic turnover, or a "in situ" melatonin biosynthesis and endocrine secretion by the same B cells. The higher ZIO-positivity of type B cells in female than male may be related also to the influence of sexual steroid hormones, that characterizes the porphyrin pigment amount involved in melatonin oxidation.
Animals↗
Lamellar and "club-shaped" corpuscular nerve endings in human gingival mucosa. A light and electron microscopic study.
A study on the presence of corpuscular nerve endings in human gingival mucosa was performed using both light and transmission electron microscopic (TEM) techniques. Both round and oval lamellar corpuscles were detected by light microscopy. They were located either subepithelially, close to the basement membrane, or within the papillae, deeply invaginated into the overlying epithelium. TEM techniques showed convoluted structures with unmyelinated fibre arborizations leading to an afferent fibre supported by the so called lamellar cells. The presence of blood vessels, collagenous fibrils, desmosome-like junctions, cytoplasmic organelles, as well as the similarity with some previously described mechanoreceptors, suggested the role of such corpuscular nerve endings in transmitting a nervous impulse induced by mechanical stimulation. Other simpler structures were also observed and named "club-shaped" corpuscles: they could support the more complex ones in responding to the strengths and the movements directly influencing the gingival mucosa.
Gingiva↗
The presence of implant materials influences fibronectin arrangement and cell growth in fibroblast cultures.
The nature of the bone-implant interface has been much focused in investigating dental implant materials, whereas the relationship between implant and fibroblasts has received much less attention. To evaluate the biocompatibility degree of an implant material, both cell adhesion and cell growth must be tested in the presence of the implant. Four dental implant (A,B,C,D) made in titanium alloy and one of them (C) hydroxyapatite (HA)-coated in fibroblast cultures (48 and 72 h) were tested, by performing immunocytochemical techniques and then by observing fibronectin (FN) arrangement for cell adhesion and counting 5-bromodeoxyuridine (5-BrdU) to evaluate cell proliferation. Different FN arrangements were observed-i.e. organized in fibrils, or in focal adhesion plaques, as well as dispersed in the intercellular space-which varied for the different implants employed at the various culture stages. Equally, the per cent ratio of 5-BrdU positive cells was different, with a more significant increase (p < 0.001) between 48 and 72 h for implant C and the controls. It was observed that the higher percentages of 5-BrdU positive cells were in cultures where FN was organized mainly in focal adhesions, as well as 5-BrdU positive cells increased after 72 h in cultures, which after 48 h presented much FN dispersed in the intercellular space. It may be assumed that a correlation exists between FN arrangement and the percentage of 5-BrdU positive cells and that these two parameters vary in the presence of the different implants. Moreover, the HA-coated implant seems to be the most biocompatible in fibroblast cultures.
Biocompatible Materials↗
Atypical isoenzymes of PKC-iota, -lambda, -mu: relative distribution in mouse foetal and neonatal organs.
PKC-iota, -lambda and -mu are recently cloned and characterized as members of the alternative group of this family of protein kinases. We performed an immunohistochemical study about the expression of PKC-iota, -lambda and -mu in tissues and organs of mouse foetuses and newborn mice, in order to evaluate their peculiar functions during the developmental stages. The specificity of the antibodies was tested by Western-blotting experiments with whole extracts from 15-day mouse foetuses or neonatal mice. Cryostat sections of mouse foetal and neonatal organs were reacted with monoclonal (anti -iota and -lambda) or polyclonal (anti -mu) antibodies. The staining intensity was expressed in standardized arbitrary units from 0 to 250. An almost general increasing expression from foetal to neonatal samples, with the highest immunostaining for PKC-mu, was observed in all investigated organs, thus suggesting that PKC atypical isoforms are quantitatively expressed with a significant relationship with the proceeding of developmental phases. Marked differences were revealed also as far as the distribution of these isoforms was concerned in well defined cell populations, particularly in lung, stomach and kidney. These results suggest that various cell populations, in important phases of proliferating and differentiating events, produce atypical PKC isoforms that are conceivably involved in regulating signal transducing events. Therefore, PKC-iota, -lambda, -mu isoforms may have well defined functions in regulating the growth or the program of cell proliferation and differentiation.
Animals↗