Use of a modified vertical holding appliance for open bite interceptive treatment in growing patients.

BACKGROUND: The aim of this paper is to illustrate the use of a modified vertical holding appliance (G-VHA) to obtain the vertical control of maxillary molars and tongue stimulation in order to achieve a transverse activation in growing patients with dental open bite without the patient's compliance. CASE REPORTS: The G-VHA is a modified trans-palatal bar with a resin pad covering the Omega central loop and two adjunctive lateral loops to ensure the bar flexibility. The G-VHA is designed to direct the force of the tongue against the upper molars to generate intrusion and at the same time to stimulate and re-educate the tongue. Two cases of dental open bite in growing patients are illustrated. Both patients were successfully treated, and the open bite was fully corrected thanks to molar intrusion, following counterclockwise rotation of the mandible and tongue correction. Finishing of alignment was performed in phase II of the treatment with conventional appliances. CONCLUSION: The G-VHA proved to be effective in controlling the vertical position of maxillary molars promoting the counter-clockwise rotation of the mandible and stimulating a different tongue posture.

In vitro susceptibility of nondermatophyte molds isolated from onycomycosis to antifungal drugs.

Despite many advances in antifungal drug development and therapy, onychomycosis due to nondermatophyte molds (NDM) remains difficult to treat. Using a reference microdilution method (CLSI M38-A), the antifungal susceptibility to bifonazole, ciclopiroxolamine, fenticonazole, itraconazole, ketoconazole, miconazole, terbinafine and tioconazole of 64 molds isolated from toenail onychomycosis was studied. All the strains showed good susceptibility to ciclopiroxolamine. Aspergillus had excellent susceptibility to itraconazole followed by miconazole, ketoconazole, tioconazole, fenticonazole and terbinafine. The isolated species had variable susceptibility to bifonazole. Scopulariopsis had wide MIC ranges for all antifungal drugs tested except ciclopiroxolamine. Fusarium and Acremonium had reduced susceptibility to antifungal drugs tested. Nevertheless, some strains show low MICs for ketoconazole, miconazole and tioconazole.Studies to evaluate in vitro susceptibility testing using CLSI methods for NDM onychomycosis should be undertaken.

Growth hormone response to growth hormone-releasing hormone varies with the hypothalamic-pituitary abnormalities.

We determined growth hormone (GH) and insulin-like growth factor I (IGF-I) levels after a 3 h infusion of escalating doses of growth hormone-releasing hormone (GHRH(1-29)) followed by a bolus injection in hypopituitary patients with marked differences in pituitary features at magnetic resonance imaging (MRI) in order to evaluate further the contribution of MRI in the definition of pituitary GH reserve in GH-deficient patients. Twenty-nine patients (mean age 14.5 +/- 4.0 years) were studied. Group I comprised 13 patients: seven with isolated GH deficiency (IGHD) (group Ia) and six with multiple pituitary hormone deficiency (MPHD) (group Ib) who had anterior pituitary hypoplasia, unidentified pituitary stalk and ectopic posterior pituitary at MRI, Group II consisted of eight patients with IGHD and small anterior pituitary/empty sella, while in group III eight had IGHD and normal morphology of the pituitary gland. Growth hormone and IGF-I levels were measured during saline infusion at 08.30-09.00 h, as well as after infusion of GHRH (1-29) at escalating doses for 3h: 0.2 micrograms/kg at 09.00-10.00 h, 0.4 micrograms/kg at 10.00-11.00 h, 0.6 micrograms/kg at 11.00-12.00 h and an intravenous bolus of 2 micrograms/ kg at 12.00 h. In the group I patients, the peak GH response to GHRH(1-29) was delayed (135-180 min) and extremely low (median 2mU/l). In group II it was delayed (135-180 min), high (median 34.8 mU/l) and persistent (median 37.4 mU/l at 185-210 min). In group III the peak response was high (median 30.8 mU/l) and relatively early (75-120 min) but it declined rapidly (median 14.4 mU/l at 185-210 min). In one group I patient, GH response increased to 34.6 mU/l. The mean basal value of IGF-I levels was significantly lower in group I (0.23 +/- 0.05 U/ml) than in groups II (0.39 +/- 0.13U/ ml, p < 0.01) and III (1.54 +/- 0.46 U/ml, p < 0.001) and did not vary significantly during the GHRH(1-29) infusion. The present study demonstrates that the impaired GH response to 3 h of continuous infusion of escalating doses of GHRH(1-29) was strikingly indicative for pituitary stalk abnormality, strengthening the case for use of GHRH in the differential diagnosis of GH deficiency. The low GH response, more severe in MPHD patients, might be dependent on the residual somatotrope cells, while the better response (34.6 mU/l) in the group Ia patients might suggest that prolonged GHRH infusion could help in evaluating the amount of residual GH pituitary tissue. Pituitary GH reserve, given the GH response to GHRH infusion in GH-deficient patients with small anterior pituitary/empty sella, seems to be maintained.

The effects of soft-water acclimation on gill structure in the rainbow trout Oncorhynchus mykiss.

Rainbow trout (Oncorhynchus mykiss) were exposed to ion-poor (soft) water to test the hypothesis that naturally induced proliferation of branchial chloride cells causes a thickening of the blood-to-water diffusion barrier. This was achieved by using a combination of scanning and transmission electron-microscopic techniques. Fish were exposed to soft-water conditions ([Na+]= 0.055 mmol l-1, [Cl-] approximately 0.029 mmol 1(-1), [Ca2+] approximately 0.059 mmol 1(-1), and [K+] approximately 0.007 mmol 1(-1)) for 1, 2, and 4 weeks. Marked chloride cell proliferation was evident at all sampling times with an approximate doubling of the gill epithelial surface area covered by chloride cells exposed to the water ("chloride cell fractional area"). The increases in chloride cell fractional area resulted from both increased numbers of cells and expanded apical surfaces of exposed individual cells. As a result of chloride cell proliferation, soft-water exposure was associated with a doubling of the lamellar blood-to-water diffusion distance from 3.26+/-0.08 microM to 6.58+/-0.43 microM as determined from transmission electron micrographs. These data demonstrated a positive correlation between chloride cell fractional area and blood-to-water diffusion distance. We conclude that, in trout, chloride cell proliferation during soft-water exposure, while presumably benefiting ionic regulation, may impair gas transfer owing to the associated thickening of the blood-to-water diffusion barrier.

Circadian rhythms of lipid and apolipoprotein pattern in adult fasted rats.

Data on circadian rhythms of serum lipids and apolipoproteins in animals and in human subjects are scarce. The goal of this study was to investigate the existence of circadian rhythms in the lipids and apolipoproteins of fasted rats. We showed that in fasted rats well-defined circadian rhythms were present in total serum triglycerides and in cholesterol and triglycerides of very low density lipoprotein (VLDL), intermediate density lipoprotein-low density lipoprotein (IDL-LDL) and high density lipoprotein (HDL). Moreover, our data clearly show that the circadian rhythm of lipoproteins is accompanied by a well defined circadian rhythm of B apoprotein, in all lipoprotein classes examined.

Individual housing modulates daily rhythms of hypothalamic catecholaminergic system and circulating hormones in adult male rats.

Circadian rhythms of hypothalamic catecholamines and their metabolites and of prolactin and corticosterone circulating hormones were determined over 24 h in group-housed (six per cage; control) and individually housed, 90-day-old male albino rats adapted to a 12:12 light/dark cycle. After 5 weeks of adaptation, in individually housed rats, norepinephrine (NE) turnover increased, since lower NE (p < 0.01) and higher MOPEG metabolite (p < 0.01) levels were measured. As concerns the dopaminergic system, individually housed rats increased both dopamine (DA) synthesis and turnover as revealed by higher DOPAC (p < 0.01) and HVA (p < 0.05) metabolites without modification of DA levels. Moreover, in individually housed rats, corticosterone (p < 0.01) and prolactin (p < 0.05) mean levels were higher than in the control group.

Branchial calcium uptake: possible mechanisms of control by stanniocalcin.

The branchial Ca(2+) uptake by teleost fish is under inhibitory control by the hormone stanniocalcin (STC) which is generated by the corpuscles of Stannius (CS). Removal of the CS in North American eel, Anguilla rostrata LeSueur, induced a rapid rise in blood calcium levels. Branchial Ca(2+) influx following the extirpation of the CS (stanniectomy, STX) increased during the first four days and stayed elevated thereafter (in agreement with previous studies). The transepithelial potential (TEP) across the gills did not change after STX and this means that the electrochemical gradient for Ca(2+) is less favourable for passive influx of Ca(2+) in STX eel. Therefore, the Ca(2+) influx in STX eels is a transcellular flux, with Ca(2+) crossing the apical and basolateral membrane barrier. The kinetics of ATP-driven Ca(2+)-transport across basolateral plasma membranes from eel gills did not change after STX. Thus, the increased Ca(2+)-influx after STX is not correlated with changes in ATP-dependent Ca(2+)-extrusion across the basolateral membrane, suggesting a regulation at the apical membrane. Moreover, STC did not affect ATP-driven Ca(2+)-transport in isolated basolateral membranes (in vitro). STC (0.1 nM) reduced cAMP levels in dispersed eel gill cells. It had no significant effect on the IP3 levels in these cells. We postulate that STC controls the permeability to Ca(2+) of the apical membranes of the Ca(2+) transporting cells of fish gills by controlling second messenger operated Ca(2+) channels in the apical membrane.

Circadian rhythms of hypothalamic norepinephrine and of some circulating substances in individually housed adult rats.

The circadian rhythms of hypothalamic norepinephrine (NE) and of circulating norepinephrine, epinephrine (E), corticosterone, aldosterone, and serotonin (5HT) were determined in group-housed and in individually housed male adult rats, adapted to a 12/12 light/dark cycle. After 5 weeks of individual housing, compared to group-housed animals, hypothalamic NE mesor decreased, while circulating NE, E, and corticosterone mesor increased. The circadian rhythms of aldosterone and 5HT were unaffected by individual housing.

Chronic administration of imipramine antagonizes deranged circadian rhythm phases in individually housed rats.

The circadian rhythms of hypothalamic serotonin (5HT), tryptophan (TP) and 5-hydroxy-indoleacetic acid (5HIAA), and serum corticosterone were determined in male Wistar rats. The animals underwent a five-week 12:12-hr light/dark cycle conditioning period and were divided into three groups: rats housed four to a cage (group C, control), rats housed individually (group I), and rats housed individually and treated for two weeks with 10 mg/kg/day of imipramine continuously administered by osmotic pumps implanted under the skin (group T). Significant differences were found in the acrophases of 5HT, TP and 5HIAA between group I and group C, and corticosterone mesor was higher in group I than in group C. On the contrary, no differences were observed between group T (individually housed, but given imipramine) and group C. Therefore, chronically administered imipramine antagonizes the circadian changes induced by individual housing.

Circadian rhythm variations in the adult rat induced by low and high protein diets administered at various stages of development.

Hypothalamic tryptophan (TP), serotonin (5HT) and 5-hydroxy-indoleacetic acid (5HIAA), serum tryptophan (free and total), and circulating corticosterone and aldosterone were measured over 24 hr in 60-day-old male rats fed high (60%) and low (6%) protein diets. The diets were administered during specific stages of rat growth: fetal phase and suckling (when the process of mitosis is most rapid), post-lactation, and from the fetal phase through to the adult stage. In all groups, there was a direct correlation between protein intake and hypothalamic and serum TP levels. Remarkable decreases in the amplitude and mesor of the aldosterone rhythm were observed when the hyperprotein diet was administered in the fetal and suckling phases, or from the fetal phase until the adult stages. The rhythm of the serotonin system was significantly altered by a low protein diet: decreased 5-HT amplitude (low protein diet in the fetal stage and suckling), decreased 5-HT amplitude and deranged 5-HIAA rhythm (low protein in the post-lactation period), deranged 5-HIAA rhythm (low protein diet throughout the experiment). Lastly, there was a remarkable increase in the corticosterone mesor in rats administered a low protein diet after weaning and in rats constantly given this diet. Growth was greatly inhibited in these two groups of animals, therefore, it cannot be excluded that the high levels of circulating hormone resulted from their debilitated condition.

Effects of individual housing on circadian rhythms of adult rats.

Circadian rhythms of hypothalamic serotonin (5HT), its precursor tryptophan (TP) and its metabolite 5-hydroxy-indoleacetic acid (5HIAA), and of prolactin and corticosterone circulating hormones were determined in group-housed and in individually-housed male rats, adapted to a 12:12 light/dark cycle. After 5 weeks of individual housing, 5HT peaked later, TP and 5HIAA peaked earlier, and the mesor level of TP and 5HIAA decreased with respect to group-housed animals. Individual housing caused an increase in the corticosterone mesor level, but did not affect amplitude or acrophase. The circadian rhythm of prolactin was unchanged by individual housing.

Tricyclic imipramine modification of the circadian rhythms of hypothalamic serotonin, its precursors and acid catabolite in individually housed rats.

Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks. Rats were individually housed and entrained to LD 12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between 5HT and 5HIAA rhythms. Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic 5HT and TP concentrations.

Circadian rhythm of circulating corticosterone and urinary excretion of catecholamines, serotonin and their catabolites in rats treated with imipramine.

The circadian rhythm of serum corticosterone was assessed in rats entrained to a 12:12 LD cycle and treated with tricyclic imipramine (25 mg/kg/day) via osmotic pumps for a period of 14 days; urinary excretion of catecholamines, serotonin and their catabolites was also assessed. We observed that imipramine did not modify the phase position of the corticosterone rhythm but rather lowered the animal's responsiveness as shown by the lower peak of corticosterone at 2000 and by the smaller amplitude of its circadian rhythm; moreover imipramine had no effect on urinary excretion of catecholamines, serotonin and their catabolites during LD cycle.

Hyperproteic diet and pregnancy of rat.

We have studied the effects of a purified diet enriched with animal protein (casein 40%, lactalbumin 20%) on different stages of rat pregnancy. We observed that hyperproteic diet, especially when administered from the first day of pregnancy, induces morphological alterations of liver, adrenal cortex, heart and kidney. Moreover, haematic dosages, carried out on 15th day of pregnancy, have shown moderate but significant increase of glucose and triglycerides and significant decrease of circulating aldosterone and corticosterone as well. Finally an early administration of hyperproteic diet causes less numerous litters and high mortality rate at birth.

No circadian rhythms of serotoninergic, alpha-, beta-adrenergic and imipramine binding sites in rat brain regions.

Bmax values of the specific binding of [3H]-WB 4101, [3H]-dihydroalprenolol, [3H]-spiperone and [3H]-imipramine to various rat brain regions were determined at 4 hr intervals over 24 hr under circadian conditions. No significant circadian rhythm of binding sites number was found for any receptor investigated in cerebral cortex, hypothalamus or brain stem. Some methodological issues are discussed.