Evaluation in a Dog Model of Three Antimicrobial Glassy Coatings: Prevention of Bone Loss around Implants and Microbial Assessments

ObjectivesThe aim of the present study is to evaluate, in a ligature-induced peri-implantitis model, the efficacy of three antimicrobial glassy coatings in the prevention of biofilm formation, intrasulcular bacterial growth and the resulting peri-implant bone loss.MethodsMandibular premolars were bilaterally extracted from five beagle dogs. Four dental implants were inserted on each hemiarch. Eight weeks after, one control zirconia abutment and three with different bactericidal coatings (G1n-Ag, ZnO35, G3) were connected. After a plaque control period, bacterial accumulation was allowed and biofilm formation on abutments was observed by Scanning Electron Microscopy (SEM). Peri-implantitis was induced by cotton ligatures. Microbial samples and peri-implant crestal bone levels of all implant sites were obtained before, during and after the breakdown period.ResultsDuring experimental induce peri-implantitis: colony forming units counts from intrasulcular microbial samples at implants with G1n-Ag coated abutment remained close to the basal inoculum; G3 and ZnO35 coatings showed similar low counts; and anaerobic bacterias counts at control abutments exhibited a logarithmic increase by more than 2. Bone loss during passive breakdown period was no statistically significant. Additional bone loss occurred during ligature-induce breakdown: 0.71 (SD 0.48) at G3 coating, 0.57 (SD 0.36) at ZnO35 coating, 0.74 (SD 0.47) at G1n-Ag coating, and 1.29 (SD 0.45) at control abutments; and statistically significant differences (p<0.001) were found. The lowest bone loss at the end of the experiment was exhibited by implants dressing G3 coated abutments (mean 2.1; SD 0.42).SignificanceAntimicrobial glassy coatings could be a useful tool to ward off, diminish or delay peri-implantitis progression.     

Selective enzymatic hydrolysis of aromatic diesters using esterase from Brevibacterium imperiale B222

Summary A practical procedure has been developed for the chemoselective microbial hydrolysis of aromatic dicarboxylic esters to give the corresponding monoesters, using cellular lysate and whole cell of Brevibacterium imperiale B222. The produced monoesters can be transformed into hydroxyacids, useful intermediates in the synthesis of polyesters.     

Effects of colchicine on anther and microspore culture of bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The aim of this work was to study the effects of colchicine application on chromosome doubling and androgenic response in anther and microspore culture of different bread wheat genotypes. Colchicine was applied during a mannitol stress pretreatment or during the first 48 h of culture at concentrations of 0, 150 and 300 mg l⁻¹. When colchicine was applied during stress pretreatment, the percentage of doubling depended on genotype and concentration. A significant increase in doubling was observed with 300 mg l⁻¹ in the low androgenic responding cv. Caramba. Colchicine incorporation during the first hours of culture improved percentage of doubling in all genotypes, in both anther and microspore culture. Application of 300 mg l⁻¹ colchicine improved the percentage of doubling in the two low responding genotypes, to 118% of control in DH24033, and 75% in Caramba in microspore and anther culture, respectively. Concerning the androgenic response, the effect of colchicine on embryo formation and percentage of green plants depended on the genotype and on the culture method. In cv. Pavon, a 2- and a 3-fold increase in percentage of embryogenesis and green plants, respectively, were obtained with 300 mg l⁻¹ colchicine in microspore culture. However, no significant differences in these two variables were observed in anther culture. The number of green doubled haploid (DH) plants reflects the index of success of the procedure. Regardless of the culture method, when colchicine was incorporated during the first hours of culture, the number of green DH plants increased significantly in three of four genotypes. These results confirm the usefulness of colchicine application during the first hours of culture in wheat breeding programs.     

Genetic differentiation of Elysia timida (Risso, 1818) populations in the Southwest Mediterranean and Mar Menor coastal lagoon

Genetic variation at 10 enzyme loci was analysed in Elysia timida sacoglossan mollusc samples, originating from both coastal lagoon and marine sites. The observed heterozygosity ranged from 0.390 (Los Urrutias) to 0.277 (Tabarca). Marine and coastal lagoon populations were characterised by exclusive alleles.     

THE INTRACELLULAR MEMBRANES OF BLASTOMYCES DERMATITIDIS

Edwards , George A., and Mercedes R. Edwards . (Div. Labs, and Research, N.Y.S. Dept. of Health, Albany.) The intracellular membranes of Blastomyces dermatitidis. Amer. Jour. Bot. 47 (8): 622–632. Illus. 1960.—The yeast cells of Blastomyces dermatitidis have been studied in thin sections with the electron microscope. The cell is multinucleate, and the nuclei are frequently interconnected by their outer limiting membranes. The cell is bordered by a cell wall and the plasma membrane, which may be seen in direct continuity with the nuclear envelope. The cytoplasm contains numerous mitochondria, many profiles of the endoplasmic reticulum, and few multivesicular bodies. The membranes of all the constant cellular components are interconnected. Mitochondria appear to be formed from any of several membrane systems. The micromorphology of the cell suggests efficiency of communication and cytoplasmic mobility.     

Serum concentrations of 1,25-dihydroxyvitamin D3 in Platyrrhini and Catarrhini: A phylogenetic appraisal

We measured the serum concentration of 25-hydroxyvitamin D₃ (25-OH-D₃) and 1,25-dihydroxyvitamin D₃ (1,25-[OH]₂-D₃) in 23 different Platyrrhines from four different genera and in 21 Catarrhines from six different genera in residence at the Los Angeles Zoo. The mean (±S.E.) serum concentration of 1,25-(OH)₂-D₃ was significantly greater in Platyrrhines (810 ± 119 pg/ml) than in Catarrhines (61 ± 5 pg/ml), suggesting that high circulating concentrations of the active vitamin D hormone were a characteristic of New World primates in both the Cebidae and Callitrichidae family. This increase in the serum concentration of 1,25-(OH)₂-D₃ is probably an adaptational response on the part of Platyrrhini to offset a relative decrease in the concentration of specific receptor for 1,25-(OH)₂-D₃ in target tissues for the hormone.     

Determination of selenium and iodine in human thyroids.

This study focuses on the determination of selenium and iodine in human thyroids. The glands were digested using nitric acid in a microwave oven. Selenium was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) using a new sample introduction system consisting of a reduction system coupled to a hydride generation nebulizer (DHGN). Iodine was determined by using the Sandell-Kolthoff procedure. The detections limits were 0.2 ng/mL and 0.3 ng/mL for the determination method of selenium and iodine, respectively. The amount of iodine in the whole gland was 3.44 +/- 1.11 microg/g. The lowest iodine level was 2.34 microg/g and the highest 5.21 microg/g. The lowest selenium concentration for a single sample was 505 +/- 51 ng/g and the highest 1495 +/- 204 ng/g depending on the fraction of the gland selected.     

Role of IL-6 in Asthma and Other Inflammatory Pulmonary Diseases

The incidence and severity of chronic lung diseases is growing and affects between 100 and 150 million people worldwide and is associated with a significant rate of mortality. Unfortunately, the initial cause that triggers most chronic lung diseases remains unknown and current available therapies only ameliorate, but do not cure the disease. Thus, there is a need for identification of new targets and development of novel therapies especially for those most severely affected. IL-6, like other inflammatory cytokines, has been shown to be elevated in different lung diseases, but it was considered a byproduct of ongoing inflammation in the lung. However, recent studies support a dissociation of IL-6 from inflammation in the lung and suggest that this cytokine plays an active role in pathogenesis of asthma and, in all likelihood, COPD. IL-6 may therefore be a germane target for treatment of these and other chronic lung disease. Here, we provide an overview of the studies in mouse models and human patients that provide support for the involvement of IL-6 in lung diseases.     

Effect of high temperatures and ash on germination of ten species from gorse shrubland

Seeds of ten species of Cistaceae, Ericaceae and Poaceae were examinated to compare their responses to high temperatures and ash, simulating the direct effect of fire on germination. A variable response to these factors between families and within species from the same family was detected.In Cistaceae, heat treatment pre-sowing stimulated germination. In Ericaceae, germination was stimulated by thermic shock, but a wide range of response was detected (between all four species), from Erica ciliari, very sensitive, to Daboecia cantabrica and Calluna vulgaris which showed no significant response. The range of reaction shown by the species of this family suggest that the size of the seeds is directly related to the difference in response, at least in species with a similar structure. In Poaceae, germination was not found to be dependent upon thermic shock.The effect of ash varies in magnitude. Although it decreased the germination percentage in all species, in Avenula marginata (Poaceae) the effect was not statistically significant, whilst in Ericaceae, particularly in those showing the highest levels of germination in the control (C. vulgaris and E. umbellata), the effect is to inhibit germination completely. In respect to the effect of ash the families could be arranged in the order Ericaceae>Cistaceae>Poaceae.Complex interactions between various dormancy types and seed size could explain these results. In species which depend on physical dormancy temperature has an important role. When other dormancy type is dominant in the control of germination, the medium characteristics could have a relevant role on seed response. In addition, the seed-size could determine the threshold of tolerance to temperature.