The fluoride content of teeth in the canton of Vaud 5 years after the introduction of salt fluoridation

Fluroide concentrations in teeth from the canton of Vaud were about at the same level reported from regions with 1,0 ppm F in the drinking water and from children receiving fluoride tablets during tooth formation age.     

Effect of adrenaline on the secretory activity of the ocular ciliary body in rabbits

In intact rabbits and in rabbits with intracerebral unilateral section of the n. oculomotorius, instillation of 2 drops of 0.1% adrenaline into the conjunctival sack increased and then decreased the intraocular pressure (IOP); i.v. administration of adrenaline (50 mcg) or electrophoresis decreased IOP. In conditions of disturbed parasympathetic innervation of the eye its sensitivity to adrenaline increased as revealed by a sharper lowering of IOP.     

Measurements of exit rates to distinguish between facilitated and simple diffusion

A modification of the method of Sen and Widdas (J. Physiol. London 160:392-403, 1962) was used to measure the rate of exit of several nonelectrolytes from erythrocytes of various species. In spite of additional errors introduced by the larger half-saturation values of the carriers (phi) and concentrations, it was possible to distinguish between systems with small values of phi, systems with relatively large values of phi, and systems involving only simple diffusion. Approximate values of phi in millimoles and of maximum transfer rate (K) in isotonic units per minute were obtained using times and initial slopes measured on experimental curves. The following values in the foregoing units were obtained: human glucose, phi = 1.8, 1.0, K = 0.8, 1.1; human glycerol, phi = 178, 94, K = 4.3, 3.3; sheep thiourea, phi = 56, 56, K = 0.9, 0.6; and rabbit glycerol, phi = 328, 64, K = 2.2, 1.0. Simple diffusion was demonstrated for the following systems: ox-ethylene glycol; ox-glycerol; sheep-ethylene glycol; and sheep glycerol.     

Effect of cortisone on post-traumatic regeneration of mammalian skeletal muscle

Prolonged administration of cortisone to sexually immature rabbits and rats, in which m. tibialis anterior was injured preliminarily, inhibited the process of regeneration of the skeletal muscle tissue; this was expressed in the retarded growth of myosymplasts and of the muscle tubes. By the 15th postoperative day experimental rabbits (in comparison with control) showed a lesser area of muscle component of the regenerated tissue. Analysis of the intensity of methionine-H3 incorporation into the regenerating elements of the muscle tissue demonstrated a significant reduction of the label incorporation into the nuclear and cytoplasmic proteins of the myosymplasts of rats to which cortisone was given. Inhibition of the protein synthesis at the early stage of differentiation of the muscle tissue was expressed to a lesser extent than in the mature differentiated muscle fibers of the intact muscle.     

Osmotic and ionic regulation in different populations of the new zealand freshwater crayfish Paranephrops zealandicus

1. Some features of the osmoregulatory mechanism are compared in four populations of Paranephrops zeal andicus White collected form freshwaters of different ionic concentrations. 2. Crayfish from freshwaters of ca, 2-0 mM-NaCl concentration show a sustained decrease in blood concentration of ca. 8% when placed in 0-2 mM-NaCl. 3. Populations from freshwaters of ca. 0-2-0-4 mM-NaCl show lower rates of net salt loss in distilled water and higher rates of net salt uptake form dilute NaCl solutions than do populations from freshwaters of ca. 0-8-2-0 mM-NaCl. 4. Renal salt losses over the first 24 h in distilled water account for ca. 18% of the total salt loss. 5. It is suggested that P. zealandicus from environments of lowest concentration shows a similar degree of adaptation to freshwater as do crayfish of the northern hemisphere. It differs in possessing a substantially higher blood concentration.     

Comparison of calcium lactate with chlorine as a washing treatment for fresh‐cut lettuce and carrots: quality and nutritional parameters

The efficacies of calcium lactate and chlorine washing treatments of fresh‐cut lettuce and carrots were compared during storage at 4 °C over 10 days. The gas composition of packages, colour, enzyme activity, texture, sensory attributes, microflora and levels of ascorbic acid and carotenoids were evaluated at 1, 3, 7 and 10 days. Calcium lactate treatment was not significantly different to chlorine treatment (p < 0.05) in terms of maintaining colour, texture and acceptability of fresh‐cut lettuce and carrots during the entire storage period. The washing treatments did not affect levels of ascorbic acid of fresh‐cut lettuce or carrots. Carotenoid levels were higher in calcium lactate‐treated carrots than chlorine‐treated samples at the end of storage. Mesophilic, psychrotrophic and lactic acid bacteria counts were not significantly different between treatments for both vegetables. Copyright © 2005 Society of Chemical Industry     

Selenoprotein deficiency enhances radiation-induced micronuclei formation

The availability of selenium and the levels of specific selenoproteins might affect cancer risk by influencing the ability of DNA damaging agents to cause genomic instability and mutations. Transgenic mice that express reduced levels of selenoproteins and previously shown to be more susceptible to pathology associated with cancer development were used to study this possibility. These mice were exposed to X-rays and DNA damage assessed in the erythrocytes, where micronuclei formation was higher compared to the same cells obtained from irradiated wild-type controls. To determine whether the selenoprotein glutathione peroxidase-1 (GPx-1) might be involved in this protection, its levels were reduced by siRNA targeting in LNCaP human prostate cells. UV-induced micronuclei frequency was higher in these cells compared to control-transfected cells. These results indicate a role for selenoproteins in protecting DNA from damage and support human data implicating GPx-1 as a possible target of the chemoprotective effect of selenium.