Fabrication of a metal-ceramic crown to fit an existing partial removable dental prosthesis using ceramic pressed to metal technique: a clinical report

Fabricating a crown to retrofit an existing abutment tooth for a partial removable dental prosthesis (PRDP) is one of the most time-consuming and labor-intensive clinical procedures. In particular, when the patient is concerned with esthetic aspects of restoration, the task of fabricating becomes more daunting. Many techniques for the fabrication of all-metallic or metal-ceramic crowns have been discussed in the literature. This article was aimed to describe a simple fabrication method in which a retrofitting crown was fabricated for a precise fit using a ceramic-pressed-to-metal system.     

Culture at low glucose up-regulates mitochondrial function in pancreatic β cells with accompanying effects on viability

We tested whether exposure of β cells at reduced glucose leads to mitochondrial adaptions and whether such adaptions modulate effects of hypoxia. Rat islets, human islets and INS-1 832/13 cells were pre-cultured short term at half standard glucose concentrations (5.5 mM for rat islets and cells, 2.75 mM for human islets) without overtly negative effects on subsequently measured function (insulin secretion and cellular insulin contents) or on viability. Culture at half standard glucose upregulated complex I and tended to upregulate complex II in islets and INS-1 cells alike. An increased release of lactate dehydrogenase that followed exposure to hypoxia was attenuated in rat islets which had been pre-cultured at half standard glucose. In INS-1 cells exposure to half standard glucose attenuated hypoxia-induced effects on several viability parameters (MTT, cell number and incremental apoptotic DNA). Thus culture at reduced glucose of pancreatic islets and clonal β cells leads to mitochondrial adaptions which possibly lessen the negative impact of hypoxia on β cell viability. These findings appear relevant in the search for optimization of pre-transplant conditions in a clinical setting.     

Study of the migration phenomena of specific metals in canned tomato paste before and after opening. Validation of a new quality indicator for opened cans

A method for the simultaneous determination of Cd–Pb, As–Cu, Cr–Ni and Fe–Mn in canned tomato paste samples by Electrothermal Atomic Absorption Spectrometry was developed and validated. The validation procedure was conducted according to the terms of the European regulation for the official control of contaminants in foods. The validated method was applied for the determination of these metals and metalloids in 13 different tomato paste samples and the results showed that Cd content was higher than the maximum permissible value of 0.050 mg kg⁻¹ as proposed in European Regulation (EC) No 1881/2006 concerning fresh fruits and vegetables. Furthermore, a new quality indicator was evaluated in order to provide information about tomato paste quality and the appropriate storage time of an opened canned tomato paste. Finally, a migration test was accomplished based on the calculation of mass balance and the comparison of the elemental content in canned tomato paste samples and in aseptic paper pack and it was proved that Fe and Pb were the main metals migrating in tomato paste samples.     

Surgical tip: Titanium foam blocks can simplify fusion of failed total ankle replacements

Ankle arthrodesis following failed ankle replacements is a technically challenging task because of the large defect left behind after the prosthesis is removed. The usual practice is to use bulk grafts which are either autografts or allografts to fill the defect. We report our experience with the use of a titanium foam block specifically designed for fusion of failed ankle replacements. This particular method was chosen to avoid the technical difficulties and morbidities associated with the use of bulk autografts and allografts. We describe the surgical technique and early results in the first two cases performed in our unit. The satisfactory clinical and radiologic results in the two cases demonstrate the ability of the titanium foam block to simplify an otherwise complex procedure without compromising the outcome.     

Solution Behavior of Hydrolyzed Gradient Methyl/Phenyl Oxazoline Copolymers and Complexation with DNA

Partial hydrolysis of 2‐methyl‐2‐oxazoline/2‐phenyl‐2‐oxazoline gradient copolymers (MPOx copolymers) results in amphiphilic copolymers containing cationic ethylene imine, neutral hydrophilic 2‐methyl‐2‐oxazoline, and hydrophobic 2‐phenyl‐2‐oxazoline segments (HMPOx copolymers). The solution behavior of the HMPOx copolymers has been investigated in water, phosphate buffer saline (PBS), and fetal bovine serum (FBS) by static, dynamic, and electrophoretic light scattering and fluorescence spectroscopy. The copolymers form stable spherical aggregates in aqueous media with positive surface charge. The aggregates are found to interact extensively with proteins in FBS solutions. Soluble HMPOx/DNA complexes have also been formed in aqueous media at certain HMPOx/DNA compositions due to electrostatic interactions. The polyplexes have been studied in terms of structure and colloidal stability.

     

Amplitude of the Electrocardiographic QRS Complexes during and after Severe Pulmonary Edema

There is recent evidence that anasarca peripheral edema, irrespective of its etiology, attenuates ECG QRS potentials. Pulmonary edema (PE) also is thought to cause reduction in the amplitude of QRS complexes. The case reported herein is of a patient with severe PE, hypertension, left ventricular diastolic dysfunction, and no peripheral edema who did not show changes in the QRS complexes with the management of her pulmonary edema. Thus it appears that PE does not attenuate the amplitude of QRS complexes, and alleviation of this condition does not cause augmentation of QRS voltage. This is in contrast to alterations of peripheral edematous states in the setting of congestive heart failure, which result in changes in the QRS amplitude, as shown previously.     

Vanadyl‐TrBR4‐Catalyzed Oxidative Polymerization of Diphenyl Disulfide

A newly established catalyst system for oxygen‐oxidative polymerization of diphenyl disulfide is reported. Combination of vanadyl compounds (e.g., VO(acac)₂) and triphenylmethylium tetrakis(pentafluorophenyl)borate (TrB(C₆F₅)₄) proceeds the polymerization to give poly(1,4‐phenylene sulfide) (PPS) at 100 °C. When triphenylmethylium tetrafluoroborate (TrBF₄) is applied with vanadyl tetraphenylporphyrin (VO(TPP)) or N,N′‐(ethylenebis(salicylideneaminato))oxovanadium (VO(salen)), PPS is also given via polymerization under conditions near 160 °C. Combination of the vanadyl complex and the borate affords the first protic‐acid‐free catalytic system for the polymerization of the disulfide, suggesting the overall reaction to produce PPS and H₂O from O₂ and protons that are eliminated from the monomer.

     

ICR小鼠卵母细胞通过旁分泌机制促进排卵关键过程

目的:利用国内医学研究常用ICR品系小鼠,在构建用于研究卵母细胞-卵丘细胞交互作用培养模型的基础上,研究卵母细胞及其产生的旁分泌因子生长分化因子9(GDF9)和骨形态发生蛋白15(BMP15)对排卵过程中的关键事件——卵丘扩展的调控作用?方法:通过显微手术制备摘除卵母细胞后的卵丘细胞复合体(OOX),并通过与卵母细胞共培养或GDF9和BMP15 处理研究卵母细胞及其特异释放的旁分泌因子对表皮生长因子(EGF)诱导卵丘扩展过程的调控?结果:成功构建了ICR小鼠OOX培养模型,发现卵母细胞及其释放的旁分泌因子GDF9和BMP15为EGF诱导卵丘扩展所必需?结论:ICR小鼠卵母细胞通过旁分泌机制促进排卵关键过程?