Inhibitory effect of fluoride on the secretion of insulin

Summary The oral administration of sodium fluoride (NaF) (40 μmol/100 body weight [bw]) to fasting rats produced an immediate fall in insulin levels and the consequent increase in glycemia. These phenomena were observed with plasma fluoride concentrations 5–15 μM. Glycemia and insulin returned to normal levels within 4–5 hours, together with the washing out of fluoride from plasma and soft tissues. The insulin secretion of isolated Langerhans islets, perifused with solutions containing 5, 10, or 20 μM fluoride, was found to be significantly inhibited as a function of fluoride levels, both with basal and stimulatory concentrations of glucose. One hour after the intake of 60 mg of NaF, fasting human volunteers showed increased fluoride (5–15 μM) together with a significant fall of plasma insulin levels.     

Drawn gelatin films with improved mechanical properties

Chain anisotropic distribution in gelatin films has been obtained by uniaxial stretching at constant relative humidity, followed by air drying and successive cross-linking with glutaraldehyde. The drawn samples have been characterized by mechanical tests, differential scanning calorimetry and scanning electron microscopy. The Young’s modulus, E, and the stress at break, σ_b, increase linearly with the draw ratio and reach values which are about five times those characteristic of undrawn samples. Furthermore, on stretching the alignment of the gelatin strands along the direction of deformation increases while the thickness of the layers decreases significantly. The renaturation level, that is the fraction of gelatin in a collagen-like structure, has been calculated as the ratio between the melting enthalpy of gelatin samples and that of tendon collagen. The results indicate that the improvement of mechanical properties achieved by drawn gelatin is closely related to the renaturation level. The experimental approach utilized to induce segmental orientation in gelatin films, allows to obtain anisotropic materials with improved mechanical properties in the direction of deformation, and can be usefully applied in the preparation of biomaterials.     

Bonelike apatite growth on hydroxyapatite-gelatin sponges from simulated body fluid.

In vitro bioactivity of gelatin sponges and hydroxyapatite-enriched gelatin sponges was tested through evaluation of the variations in their composition and morphology after soaking in simulated body fluid (1.5) for periods up to 21 days at 37 degrees C. The presence of hydroxyapatite inside the sponges promotes the deposition of bonelike apatite crystals. The deposits are laid down as spherical aggregates, with mean diameters increasing from about 1-2 microm, after 4 days of soaking in simulated body fluid solution, up to about 3.5 microm in the samples soaked for 21 days. Simultaneously, the relative amount of inorganic phase increases up to about 56% wt, leading to a composite material with a composition quite close to that of bone tissue. The inorganic phase is a poor crystalline carbonated apatite similar to trabecular bone apatite.     

Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations

It has previously been shown that, in the heterozygous state, mutations in the SOX9 gene cause campomelic dysplasia (CD) and the often associated autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one recurrent mutation were characterized in one SOX9 allele each, and in one case, no mutation was found. Four missense mutations are all located within the high mobility group (HMG) domain. They either reduce or abolish the DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense and three frameshift mutations identified, two leave the C-terminal transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or almost completely intact. When tested in cell transfection experiments, the recurrent nonsense mutation Y440X, found in two patients who survived for four and more than 9 years, respectively, exhibits some residual transactivation ability. In contrast, a frameshift mutation extending the protein by 70 residues at codon 507, found in a patient who died shortly after birth, showed no transactivation. This is apparently due to instability of the mutant SOX9 protein as demonstrated by Western blotting. Amino acid substitutions and nonsense mutations are found in patients with and without XY sex reversal, indicating that sex reversal in CD is subject to variable penetrance. Finally, none of 18 female patients with XY gonadal dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP assays, providing evidence that SOX9 mutations do not usually result in XY sex reversal without skeletal malformations.      

Dapsone hydroxylamine-mediated alterations in human red blood cells from endometriotic patients

Endometriosis, an estrogen-dependent chronic gynecological disease in women of reproductive age, is characterized by a systemic inflammation status involving also red blood cells (RBCs). In this study, we evaluated how the protein oxidative status could be involved in the worsening of RBC conditions due to dapsone intake in endometriotic women in potential treatment for skin or infection diseases. Blood samples from two groups of volunteers, control group (CG) and endometriosis patient group (PG), were analyzed for their content of band 3 tyrosine phosphorylation (Tyr-P) and high molecular weight aggregate (HMWA) in membranes, and glutathione (GSH) content and carbonic anhydrase (CA) activity in cytosol. In endometriotic patients, RBC showed the highest level of oxidative-related alterations both in membrane and cytosol. More interestingly, the addition of dapsone hydroxylamine (DDS-NHOH) could induce further increase of both membranes and cytosol markers, with an enhancement of CA activity reaching about 66% of the total cell enzyme amount. In conclusion, in PG the systemic inflammatory status leads to the inability of counteracting adjunctive oxidative stress, with a potential involvement of CA-related pathologies, such as glaucoma. Hence, the importance of the evaluation of therapeutic approaches worsening oxidative imbalance present in PG RBC is underlined.     

Assessment of nose protector for sport activities: finite element analysis

Abstract – There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s^?1 for 9.1 μs. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.13–0.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high‐impact conditions.     

Inhibition of the mitochondrial ATP synthesis by polygodial, a naturally occurring dialdehyde unsaturated sesquiterpene

Polygodial is a naturally occurring sesquiterpene dialdehyde that exhibits several pharmacologically interesting activities. Among them, its antifungal properties have been more thoroughly studied. The mitochondrial ATPase has been suggested as one of the possible targets for polygodial action. However, its mechanism of action is not well defined yet. The effect of polygodial on the mitochondrial energy metabolism is described in this paper. Polygodial inhibited ATP synthesis coupled to succinate oxidation in beef-heart submitochondrial particles at concentrations (IC(50)=2.4+/-0.1 microM) which marginally affected electron transport and ATPase activity (IC(50)=97+/-4 microM). A transitory stimulation of the electron transport in intact rat liver mitochondria in state 4 was also obtained at low polygodial concentrations (EC(50)=20+/-4 microM). These results suggest that polygodial uncouples ATP synthesis from electron transport at low concentrations. Similar concentrations of polygodial partially abolished the ANS fluorescence enhancement (IC(50)=2.2+/-0.4 microM) induced by succinate oxidation in submitochondrial particles but did not collapse the DeltapH. We postulate that polygodial uncouples mitochondrial ATP synthesis by affecting the electrical properties of the membrane surface and consequently collapsing the membrane potential (Deltapsi) and/or the localized transmembrane pH difference (DeltapH(S)) without affecting the DeltapH between the two bulk aqueous phases (DeltapH(B)). The relevance of these findings for the understanding of the biochemical basis of the antifungal activity of polygodial and the evaluation of its potentiality as a therapeutic agent are discussed.     

Befunde in den Hauptentwicklungsstufen des Gebisses bei Dysgnathieträgern

Zusammenfassung In dieser Arbeit wurden die Gebisse von 31 männlichen und 45 weiblichen Dysgnathieträgern mit Hilfe des Berliner Meßsystems vermessen und die Ergebnisse mit Hilfe eines Computers ausgewertet. Es erfolgt der Vergleich der Parameter zwischen Probanden mit Progenie, Kreuzbiß, offenem Biß und Schmalkiefer. Die Veränderung der Werte wurden longitudinal in den Hauptentwicklungsstufen Milchgebiß, Wechselgebiß und im bleibenden Gebiß untersucht. Dabei werden auch nach der Behandlung noch zwischen den Anomaliegruppen bei einzelnen Werten signifikante Unterschiede gefunden.

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Summary In this study dental plaster casts of 31 male and 45 female subjects were measured using the Berlin measurement system and evaluated with the aid of a computer. The parameters of subjects with class III malocclusion, crossbite, open bite and class II/1 malocclusion were compared. The changes were studied longitudinally in the main developmental stages, namely the deciduous, mixed and permanent dentitions. Significant differences were found also following treatment between the malocclusion groups.

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Résumé On a mesuré les dentures de 31 hommes et 45 femmes présentant des dysgnathies à l'aide du système de mesure mis au point à Berlin; les valeurs ainsi établies on fait l'objet d'un traitement sur ordinateur. On a procédé à la comparaison des paramètres des sujets atteints de prognathie inférieure, occlusion croisée, béance et endognathie. On a étudié la modification des valeurs de manière longitudinale, en suivant les principales étapes d'évolution: denture lactéale, denture mixte et denture permanente. L'examen a permis, même après le traitement, d'établir, pour chacune des valeurs, des différences importantes d'un groupe d'anomalie à l'autre.