Influence of oxygen inhibition on the surface free energy and enamel bond strength of self-etch adhesives

We compared the surface free energies and enamel bond strengths of single-step self-etch adhesives with and without an oxygen-inhibited layer. The adhesives were applied to the enamel surfaces of bovine incisors, light irradiated, and the oxygen-inhibited layer was either retained or removed with ethanol. The surface free energies and their components (γ(S)(LW), γ(S)(+), and γ(S)(-)) were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The enamel bond strengths of specimens with and without the oxygen-inhibited layer were measured. For all surfaces, the value of the estimated surface tension component γ(S)(LW) was relatively constant. The value of the γ(S)(+) component increased slightly when the oxygen-inhibited layer was removed, whereas that of the γ(S)(-) component decreased significantly. The enamel bond strengths of the self-etch adhesives were significantly lower in the specimens without an oxygen-inhibited layer. The oxygen-inhibited layer therefore appeared to promote higher enamel bond strength.     

Chemoradiotherapy for patients with recurrent lymph-node metastasis or local recurrence of gastric cancer after curative gastrectomy

Objectives

Whether chemoradiotherapy (CRT) is clinically beneficial for the management of postoperative recurrence of advanced gastric cancer remains unclear. We retrospectively studied treatment outcomes in patients who had unresectable localized recurrence after surgery for advanced gastric cancer and evaluated the safety and efficacy of CRT.

Methods

The study group comprised 21 patients who received concurrent CRT for unresectable localized recurrence after undergoing R0 resection for stage II/III advanced gastric cancer. Localized recurrence was defined as a few or limited recurrent lesions.

Results

The recurrence pattern was anastomotic recurrence in 7 patients, abdominal lymph-node recurrence in 12, and anastomotic recurrence plus abdominal lymph-node recurrence in 2. The median total dose of radiotherapy was 48.6 Gy (range 39.6–56.0), and the CRT completion rate was 100 % (21 of 21 patients). CRT-related grade 3 or higher toxicity comprised neutropenia in 33.3 % of patients and anorexia in 9.5 %. The response rate was 61.9 % (complete response 38.1 %, partial response 23.8 %). The median overall survival was 35.0 months.

Conclusions

We conclude that CRT may become one treatment strategy for the management of unresectable localized recurrence after curative resection of advanced gastric cancer.

     

Uptake and intracellular activity of NM394, a new quinolone, in human polymorphonuclear leukocytes.

The uptake of NM394, a new quinolone, by and its subsequent elution from human polymorphonuclear leukocytes were studied and compared with those of ofloxacin and ciprofloxacin. The kinetics of the uptake of NM394 was similar to that of ciprofloxacin. The maximum intracellular-to-extracellular concentration ratio was 12.3, compared with 8.6 for ciprofloxacin and 4.9 for ofloxacin at the extracellular concentration of 20 micrograms/ml. The elution of NM394 from human polymorphonuclear leukocytes occurs relatively slowly; 5 min after the removal of extracellular NM394, nearly 100% still remained in polymorphonuclear leukocytes, compared with ofloxacin, which was so rapidly eluted that only 12% remained. The uptake of NM394 was significantly decreased at 4 degrees C and by the presence of NaCN but was not affected by the presence of L-glycine, L-leucine, L-serine, adenosine, or NaF. NM394 showed intracellular activity at a concentration of 0.1 microgram/ml that significantly reduced the number of phagocytosed Pseudomonas aeruginosa cells with 2 h of incubation. These results suggest that uptake of NM394 by human polymorphonuclear leukocytes occurs via an active transport system differing from that of ofloxacin, whose uptake is affected by the presence of L-glycine and L-leucine, and that once accumulated, NM394 remains intracellularly active and participates in protection against bacterial infection.     

Diabetes,Collagen, and Bone Quality

Diabetes increases risk of fracture, although type 2 diabetes is characterized by normal or high bone mineral density (BMD) compared with the patients without diabetes. The fracture risk of type 1 diabetes as well as type 2 diabetes increases beyond an explained by a decrease of BMD. Thus, diabetes may reduce bone strength without change in BMD. Whole bone strength is determined by bone density, structure, and quality, which encompass the micro-structural and tissue material properties. Recent literature showed that diabetes reduces bone material properties rather than BMD. Collagen intermolecular cross-linking plays an important role in the expression of bone strength. Collagen cross-links can be divided into beneficial enzymatic immature divalent and mature trivalent cross-links and disadvantageous nonenzymatic cross-links (Advanced glycation end products: AGEs) induced by glycation and oxidation. The formation pathway and biological function are quite different. Not only hyperglycemia, but also oxidative stress induces the reduction in enzymatic cross-links and the formation of AGEs. In this review, we describe the mechanism of low bone quality in diabetes and the usefulness of the measurement of plasma or urinary level of AGEs for estimation of fracture risk.     

Effects of cicletanine on the urinary excretion of prostanoids and kallikrein,and on renal function in man

Summary The effects of cicletanine, a new antihypertensive agent, on the prostaglandin-kallikrein system and the reninangiotensin system were studied. A single oral dose of 200 mg cicletanine or placebo was administered to 9 healthy male volunteers, with samples of blood and urine obtained before and 2 hours after drug administration. Cicletanine increased the urine flow, urinary excretion of sodium, and fractional excretion of sodium by 47%, 115%, and 104%, respectively. While the excretion of 6-keto-prostaglandin-F₁ was enhanced significantly, urinary excretion of thromboxane-B₂, prostaglandin-E₂, and kallikrein were unchanged. Cicletanine also did not alter plasma renin activity, plasma aldosterone concentration, or creatinine clearance. These observations suggest that cicletanine may suppress sodium reabsorption at the nephron, and it may stimulate prostacyclin generation with no effect on that of thromboxane-A₂. Thus cicletanine may be beneficial in the management of cardiovascular disorders in which the equilibrium between prostacyclin and thromboxane is disturbed.     

Dosimetric comparison of absolute and relative dose distributions between tissue maximum ratio and convolution algorithms for acoustic neurinoma plans in Gamma Knife radiosurgery

Background

The treatment planning for Gamma Knife (GK) stereotactic radiosurgery (SRS) that performs dose calculations based on tissue maximum ratio (TMR) algorithm has disadvantages in predicting dose in tissue heterogeneity. The latest version of the planning software is equipped with a convolution dose algorithm as an optional extra and the new algorithm is able to compensate for head inhomogeneity. However, the effect of this improved calculation method requires detailed validation in clinical cases. In this study, we compared absolute and relative dose distributions of treatment plans for acoustic neurinoma between TMR and the convolution calculation.

Methods

Twenty-nine clinically used plans created by TMR algorithm were recalculated by convolution method. Differences between TMR and convolution were evaluated in terms of absolute dose (beam-on time), dosimetric parameters including target coverage, selectivity, conformity index, gradient index, radical homogeneity index and the dose-volume relationship.

Results

The discrepancy in estimated absolute dose to the target ranged from 1 to 7 % between TMR and convolution. In addition, dosimetric parameters of the two methods achieved statistical significance. However, it was difficult to see the change of relative dose distribution by visual assessment on a monitor.

Conclusions

Convolution, heterogeneity correction calculation, and the algorithm are necessary to reduce the dosimetric uncertainty of each case in GK SRS.