Enhanced expression of adenovirus-mediated sodium iodide symporter gene in MCF-7 breast cancer cells with retinoic acid treatment.

Increased expression of the sodium iodide symporter (NIS) is required for effective radioiodine treatment and reporter gene imaging of breast cancer. We investigated the effect of retinoic acid on adenovirus-mediated expression of the human NIS gene in the MCF-7 breast cancer cell line. METHODS: The MCF-7 cell line was infected with recombinant adenovirus carrying the human NIS gene (Rad-NIS). Levels of NIS messenger RNA (mRNA) and protein expression and radioiodine ((125)I) uptake were measured to evaluate adenovirus-mediated NIS gene expression in wild-type and Rad-NIS-infected MCF-7 cells after treatment with all-trans-retinoic acid (ATRA; 10(-8)-10(-6) mol/L). RESULTS: The transduction efficiency of adenovirus in MCF-7 cells at a multiplicity of infection (MOI) of 50 was >60%. After incubation with 10(-6) mol/L ATRA, the mRNA level in Rad-NIS-infected MCF-7 cells increased to 118.5 times that of wild-type MCF-7 cells, whereas the mRNA level in wild-type MCF-7 cells showed only a 2.1-fold increase. Western blot, immunocytochemical staining, and flow cytometry analyses showed that NIS protein expression in MCF-7 cells infected with Rad-NIS increased after ATRA treatment. With ATRA treatment, the amount of (125)I uptake increased in a dose-dependent manner (P < 0.001). The (125)I uptake in wild-type MCF-7 cells increased 3.1-, 5.5-, and 7.6-fold with treatment with 10(-8), 10(-7), and 10(-6) mol/L ATRA, respectively. Rad-NIS-infected cells showed a 4.0-fold increase in (125)I uptake. Treatment of Rad-NIS-infected cells with 10(-8), 10(-7), and 10(-6) mol/L ATRA increased (125)I uptake by 4.9-, 8.2-, and 27.6-fold, respectively, compared with wild-type MCF-7 cells. The level of NIS expression in Rad-NIS-infected MCF-7 cells treated with 10(-6) mol/L ATRA (245.0 +/- 13.7 pmol/10(6) cells) was much greater than the sum of the expression levels seen in ATRA-treated wild-type cells and Rad-NIS-infected wild-type cells. CONCLUSION: Retinoic acid increases adenovirus-mediated NIS expression in MCF-7 cells. Our results indicate that improved efficiency of NIS gene therapy or reporter imaging in breast cancer may be possible with retinoic acid treatment.     

Histoclinical Analysis of Early Colorectal Cancer

To evaluate the clinicopathologic characteristics of early colorectal cancer (ECC), histopathologic and clinical features of 90 ECC patients who underwent surgical resection (not including the endoscopic polypectomized cases) and 1704 patients with advanced colorectal cancer were analyzed. Smaller size, better histologic differentiation, less lymph node (LN) metastasis, and better clinical outcome were observed in those with ECC than in patients with more advanced lesions. LN metastasis was found in 5 patients with ECC among the 56 patients who underwent bowel resection (8.9%). Tumors with LN metastasis were more frequently associated with deep submucosal invasion, absence of an adenomatous component within the tumor, sessile configuration, and lymphovascular invasion. Tumors showing deep submucosal layer invasion were associated with a more unfavorable histologic grade, lymphovascular invasion, LN metastasis, sessile morphology, and absence of an adenomatous component within the tumor. Recurrence was observed in two patients who underwent local excision for their submucosal cancer. One of the patients was salvaged after bowel resection, but one patient died of distant metastasis. From our data analysis and literature review, extensive submucosal invasion, lymphovascular invasion, sessile configuration, and tumors with no adenomatous component should be considered high risk factors for LN metastasis and recurrence after limited therapy.     

Stable polymer brushes with effectively varied grafting density synthesized from highly crosslinked random copolymer thin films

We demonstrate the synthesis of poly(methyl methacrylate) (PMMA) and poly(styrene-b-methyl methacrylate) (P(S-b-MMA)) brushes on crosslinked random copolymer thin films, compositionally varied poly(styrene-r-glycidyl methacrylate) (P(S-r-GMA)), which can be further functionalized with a molecule featuring an initiator group upon crosslinking to form highly stable thin films. With careful optimizations, PMMA brushes were successfully grown from the surfaces of initiator functionalized P(S-r-GMA) via surface-initiated atom transfer radical polymerization. The grafting densities of the PMMA and P(S-b-MMA) brushes were effectively controlled to be in different density regimes by controlling the composition of P(S-r-GMA) and post-crosslinking functionalization methods. Synthesized BCP brushes were stable upon repetitive washing and thermal annealing processes even at high grafting density, highlighting that the outstanding stability of crosslinked P(S-r-GMA) thin films enables close examination of the morphology of thermally annealed P(S-b-MMA) brushes in different grafting density regimes.

Crosslinkable epoxy copolymers enable achieving highly stable P(S-b-MMA) brushes with controlled grafting density for close examination of phase separation behaviors.     

Significance of implant design on the efficacy of different peri-implantitis decontamination protocols

Clinical Oral Investigations - To assess the efficacy of three mechanical decontamination methods in four types of commercially available implants. Ninety-six implants of four commercial brands...     

The Effectiveness of Early Tracheostomy (within at least 10 Days) in Cervical Spinal Cord Injury Patients

Objective

This study aimed to determine the optimal time for tracheostomy by evaluating the benefits and safety of early versus late tracheostomy in spinal cord injury (SCI) patients.

Methods

We retrospectively reviewed a total of 254 patients with spinal cord injury. Of them, we selected 21 spinal cord injury patients who required tracheostomy due to long-term mechanical ventilation and analyzed their medical records. The patients were categorized into two groups. Early tracheostomy was performed day 1-10 from intubation in 10 patients and the late tracheostomy was performed after day 10 in 11 cases. We also evaluated the duration of mechanical ventilation, stay in the ICU and complications related to tracheostomy, the injury level of and clinical severity. All data was analyzed using SPSS 18.0/WIN.

Results

The early tracheostomy offered clear advantages for shortening the total ICU stay (20.8 day vs. 38.0 day, p=0.010). There was also statistically significant reduction in the total length of time on mechanical ventilation (5.2 day vs. 29.2 day, p=0.009). However, the reductions in the incidence of pneumonia (40% vs. 82%) and the length of ICU stay post to tracheostomy (6 day vs. 15 day) were found to be statistically not significant. There were also no statistically significant differences in the injury level and clinical severity between the groups.

Conclusion

We concluded that the early tracheostomy (at least 10 days) is beneficial for SCI patients who are likely to require prolonged mechanical ventilation.     

Criteria for definition of regional functional improvement on quantitative post-stress gated myocardial SPET after bypass surgery in patients with ischaemic cardiomyopathy

Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56 +/- 13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF < or = 35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% ( n = 15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml ( n = 2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (DeltaRWT), regional wall motion improvement (DeltaRWM) and regional resting (DeltaRP) and stress perfusion improvement (DeltaRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25% +/- 6% to 34% +/- 11% after CABG. A total of 229 segments were dysfunctional (wall motion < or = 2 mm, thickening < or = 20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of DeltaRWT and DeltaRWM were 0.717 and 0.620, respectively. The AUC of DeltaRWT was significantly larger than that of DeltaRWM ( P = 0.009) and the optimal cut-off value of DeltaRWT was 15%. The AUCs of DeltaRP and DeltaRstrP were not significant. The correlation coefficients between summed DeltaRWT and DeltaRWM and LVEF improvement were 0.591 and 0.472, respectively. The number of segments with a DeltaRWT of more than 15% correlated with LVEF improvement (rho = 0.533 by Spearman rank correlation). Regional wall thickening improvement showed the best correlation with global LV functional improvement after CABG. The most reliable regional criterion of myocardial viability was improvement in regional wall thickening by > or = 15% on quantitative gated SPET.     

Time course of functional recovery after coronary artery bypass grafting surgery according to the preoperative reversibility of perfusion impairment on myocardial SPECT

Purpose Ischaemic myocardial dysfunction shows different time courses of functional recovery according to the pathophysiological characteristics of the dysfunction. In this study, we investigated the time course of functional recovery according to the preoperative reversibility of perfusion impairment on myocardial single-photon emission computed tomography (SPECT) after revascularisation surgery.Methods Forty-eight patients (42 men and 6 women; mean age 59±9 years) who underwent revascularisation surgery were included in the study. ²⁰¹Tl rest/dipyridamole stress ^99mTc-sestamibi gated SPECT was performed 10±8 days before (preoperative), 105±13 days after (early follow-up) and 497±66 days after (late follow-up) surgery. Using a 20-segment model, segmental perfusion and thickening were quantified with automatic software. As an indicator of the reversibility of perfusion impairment, a reversibility score (RevS) was defined as a measure of rest minus stress perfusion values. Segmental dysfunction and functional recovery were defined from quantified thickening values. Function-recovered segments were divided into early recovery and late recovery groups, and preoperative perfusion status was compared in these groups. Function-recovered segments were also re-classified into high-RevS and low-RevS groups according to the preoperative RevS, and the time courses of functional recovery were investigated in each group.Results A total of 502 segments were included in the analysis and 263 were finally classified as function-recovered segments. Of these, 172 were in the early recovery and 91 in the late recovery group. In terms of preoperative perfusion status, RevS was 8.9±10.8 in the early recovery group and 5.4±11.0 in the late recovery group (P=0.01). When all 502 segments were classified by RevS, no difference in the proportion of final function recovery was observed between the high-RevS and the low-RevS group (54% vs 51%). However, the proportion of early recovery was higher in the high-RevS group (73%) than in the low-RevS group (57%) (P=0.01).Conclusion Ischaemic dysfunctional myocardium with reversible perfusion impairment tends to recover function earlier after revascularisation surgery than myocardium with a persistent decrease in perfusion.     

Increased urinary F(2)-isoprostanes levels in the patients with Alzheimer's disease

Isoprostanes, novel markers of oxidative injury, are generated by the free radical-mediated peroxidation of arachidonic acid (AA). They are thought to be important in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD). Using gas chromatography-mass spectrometry (GC-MS), we investigated the alteration of urinary F(2)-isoprostanes in AD patients compared to that of healthy subjects. Our results show that the levels of urinary F(2)-isoprostanes, sum of the prostaglandin F(2 alpha) isomer; prostaglandin F(2 alpha) (PGF(2 alpha)), prostaglandin F(2 beta) (PGF(2 beta)), and 8-isoprostaglandin F(2 alpha) (8-isoPGF(2 alpha)), significantly increased in AD patients (P < 0.05). The concentration of urinary 8-isoPGF(2 alpha), one of the biomarkers of oxidative stress, was not significantly different between 34 AD patients and 20 age-matched controls (P > 0.05). The PGF(2 alpha), formed by endoperoxide reductase from PGH(2), was significantly increased in AD patients, when compared with the levels of the normal controls (P < 0.05). The PGF(2 alpha), an enzymatic product of arachidonic acid, may affect the pathogenesis of AD. In addition, urinary F(2)-isoprostanes can play an important role as a biomarker in AD.     

Endoplasmic reticulum stress is involved in hydrogen peroxide induced apoptosis in immortalized and malignant human oral keratinocytes

Background: Although hydrogen peroxide may play an important role in the development of cancer, it can be an efficient inducer of apoptosis in cancer cells; the exact mechanism by which this action occurs is not completely understood in oral cancer cells. Method: In this study, the mechanisms by which H₂O₂ inhibited growth and induced apoptosis were differentially investigated using HPV‐immortalized human oral keratinocytes (IHOK) and oral cancer cells (HN4). Results: H₂O₂ treatment sensitively and dose‐dependently induced growth inhibition and typical apoptosis in IHOK and HN4 cells, as demonstrated by a decreased level of cell viability, an increased population of cells in the sub‐G₀/G₁ phase, ladder formation of the genomic DNA, chromatin condensation and accumulation of Annexin V⁺/PI⁺ cells. Furthermore, the expression of Bax, p53 and p21^WAF1/CIP1 increased, whereas the expression of Bcl‐2 decreased in immortalized and malignant keratinocytes that were treated with H₂O₂. In addition, cytochrome‐c from the mitochondria was observed in H₂O₂‐treated IHOK and oral cancer cells, and this was accompanied by the activation of caspase‐3 and ‐9. Additionally, H₂O₂ treatment induced upregulation of CHOP, GRP78 and several representative endoplasmic reticulum (ER) stress‐responsive proteins, including heme oxygenase‐1. Conclusion: Overall, these results suggest that H₂O₂ triggers apoptosis via the mitochondrial and ER stress pathway in IHOK and HN4 cells, and that increasing the cellular levels of H₂O₂ sufficiently may lead to selective killing of oral cancer cells and therefore be therapeutically useful.