[Clinical study on early loading restoration of superhydrophilic implants].

Objective: To study the clinical effect of early loading restoration a superhydrophilic implant after 1 year, so as to provide reference evidence for clinical practice. Methods: A total of 41 patients with dental defects, including 20 males and 21 females [age (52.3±13.1) years old], were enrolled in the Department of VIP, Hangzhou Dental Hospital (Pinghai Hospital) from July 2017 to January 2019. A total of 74 superhydrophilic implants were implanted, including 27 maxillary implants and 47 mandiolar implants. All patients without bone augmentation or soft tissue transplantation, the maxilla was taken impression 4 weeks after implant implantation, with 6 weeks of loading, the mandible was taken impression 2 weeks after implant implantation, with 4 weeks of loading. The stability of the implant was measured by resonance frequency analyzer before implant implantation, impression and loading. Periapical radiograph were taken immediately after mold removal, immediately after loading and reexamination 1 year after loading, to measure and record the changes in the bone level of the mesial and distal margins of the implant. Results: No biological complications occurred in all implants before loading restoration, and the implant survival rate was 100%(74/74). In 2 cases, the implant stability quotient (ISQ) value of the implant at the mandibular site was lower than 65 at 2 weeks after surgery, and the restoration was delayed. The ISQ values of the other 72 implants at the time of implantation (75.22±4.32) were not significantly different from those at the time of modeling (75.13±4.23) (P>0.05), but the ISQ values at the moment of weight loading (76.46±3.73) were significantly higher than those at modeling (P<0.05). All the early loading implants were reviewed 1 year after early loading, and none of them were loose or fell off, and the implant survival rate was 100%(72/72). X-ray measurement and evaluation showed that after 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.18±0.06) mm, among which the mandibular was (0.17±0.06) mm and the maxillary was (0.19±0.06) mm, showing no statistical difference (P>0.05). After 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.17±0.05) mm, including (0.17±0.06) mm for mandibular and (0.16±0.05) mm for maxillary, showing no statistical difference (P>0.05). Conclusions: In the limited scope of this clinical study, it has been proved that early loading of superhydrophilic implant is a safe and feasible treatment scheme, and the bone resorption at the implant edge after long-term early loading restoration needs further follow-up study.

Signalling pathway of isophorone diisocyanate-responsive interleukin-8 in airway smooth muscle cells.

This study is the first to analyse the soluble factors secreted by the bronchial epithelium after exposure to isophorone diisocyanate (IPDI) that are responsible for increasing migration and proliferation of primary normal human bronchial smooth muscle cells (BSMCs). We treated immortalised, nontumorigenic human bronchial epithelial cells (cell line BEAS-2B) and primary normal human bronchial epithelial cells (HBEC) with IPDI, and then collected the conditioned culture media (IPDI-BEAS-2B-CM and IPDI-HBEC-CM, respectively), which was added to BSMCs. Exposure of BEAS-2B cells and HBECs to IPDI increased interleukin (IL)-8 production. Culture of BSMCs with IPDI-BEAS-2B-CM and IPDI-HBEC-CM increased BSMC proliferation and migration, which are major features in asthma-related airway remodelling. Induction of BSMC proliferation and migration by IPDI-BEAS-2B-CM and IPDI-HBEC-CM was associated with increased focal adhesion kinase (FAK), Src, extracellular signal-regulated kinase (ERK)1/2 and AKT activation. Blocking FAK with a specific inhibitor significantly decreased BSMC migration and proliferation by inhibiting ERK1/2 activation. FAK and ERK1/2 inhibitor also decreased IPDI-BEAS-2B-CM-, IPDI-HBEC-CM- and recombinant human IL-8-mediated BSMC proliferation and migration, whereas blocking Rnd3 using small interfering RNA failed to affect BSMC proliferation, suggesting that Rnd3 was only involved in the regulation of BSMC migration. Our study suggests that inhibition of IL-8 or IL-8-mediated FAK/ERK/Rnd3 signalling is an attractive therapeutic target for IPDI-mediated asthma.

Regulation of the calcium signal by calmodulin.

Stimulus-response coupling mediated by calmodulin involves several steps: a transitory increase in calcium concentration from 0.1 to 10 microM, induced by external stimuli; interaction of calcium with calmodulin, accompanied by stepwise structural transitions; the coordinated interaction with and activation of the many calmodulin-regulated enzymes and proteins. The binding of calcium to calmodulin is a cooperative and selective process that is modulated by magnesium. At physiological ionic strength, and only in the presence of magnesium, a large difference is seen between the affinities of sites III and IV (0.09 X 10(6) M-1) and sites I and II (0.0007 X 10(6) M-1) for calcium. This difference, together with the positive cooperativity previously observed, explains the stepwise conformational changes induced by calcium. The interaction of calmodulin with its target proteins requires the integrity of different portions of the calmodulin molecule. Calmodulin-regulated enzymes can be divided into three classes according to their abilities to bind with and to be activated by calmodulin fragments: enzymes which are activated by the C-terminal fragment, such as the Ca2+-ATPase and phosphorylase kinase; enzymes which require both halves of the molecule, such as cyclic AMP phosphodiesterase and myosin light chain kinase; and enzymes whose interaction with calmodulin fragments is too weak to be detected by activation, such as calcineurin and the multiprotein kinase. Thus different enzymes may be activated by different calmodulin conformers and the stepwise changes exhibited by calmodulin at different calcium levels can be used to regulate different metabolic pathways.

Selective affinity chromatography with calmodulin fragments coupled to sepharose.

Calmodulin tryptic fragments 78-148, 107-148, and 1-77 coupled to Sepharose 4B were used to test the ability of different calmodulin-regulated enzymes to recognize different domains of calmodulin. Fragment 107-148, which contains a single Ca2+-binding domain, does not interact with any of the calmodulin binding proteins. Fragments 1-77 and 78-148, each of which contains two Ca2+-binding domains, have preserved their ability to interact with several calmodulin-dependent enzymes. Most of the calmodulin-regulated enzymes in brain extracts, such as cAMP phosphodiesterase, cAMP-dependent protein kinase, and the calmodulin-stimulated protein phosphatase (calcineurin) interact with fragment 78-148 in a Ca2+-dependent fashion. An ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid-sensitive, calmodulin-independent, p-nitrophenyl phosphatase does not bind to the affinity column and is resolved from calcineurin at this step. Although calmodulin-stimulated protein kinase(s) can interact with fragment 78-148, their interaction is prevented by increased ionic strength even in the presence of Ca2+. Fragment 1-77 exhibits a higher degree of selectivity than fragment 78-148. Only cAMP-dependent protein kinase and cAMP phosphodiesterase bind to fragment 1-77. These results confirm the multiple modes of interaction of calmodulin with its target proteins and provide the basis for a selective purification of calmodulin-regulated enzymes by affinity chromatography on specific calmodulin fragments coupled to Sepharose.