Twin extra-high photoluminescence in resonant double-period quantum wells

Twin extra high photoluminescence (PL) in resonant quasi-periodic double-period quantum wells (DPQWs) for higher-generation orders is demonstrated. In the DPQW, the number of maxima in the maximum values of the PL intensity is two, which is different from other quasi-periodic quantum wells (QWs) and traditional periodic QWs. The maximum PL intensity in a DPQW is also stronger than that in a periodic QW under the anti-Bragg condition and that in a Fibonacci QW. Although the peaks of the squared electric field for the twin PL are both located near the QWs, their field profiles are distinct.

Increased risk of post-transplant malignancy and mortality in transplant tourists: a nationwide population-based cohort study in Taiwan

Information on post-transplant malignancy and mortality risk in kidney transplant tourists remains controversial and is an important concern. The present study aimed to evaluate the incidence of post-transplant malignancy and mortality risk between tourists and domestic transplant recipients using the claims data from Taiwan's universal health insurance. A retrospective study was performed on 2394 tourists and 1956 domestic recipients. Post-transplant malignancy and mortality were defined from the catastrophic illness patient registry by using the International Classification of Diseases, 9th Revision. Cox proportional hazard regression and Kaplan-Meier curves were used for the analyses. The incidence for post-transplant de novo malignancy in the tourist group was 1.8-fold higher than that of the domestic group (21.8 vs 12.1 per 1000 person-years). The overall cancer recurrence rate was approximately 11%. The top 3 post-transplant malignancies, in decreasing order, were urinary tract, kidney, and liver cancers, regardless of the recipient type. Compared with domestic recipients, there was significant higher mortality risk in transplant tourists (adjusted hazard ratio = 1.2, 95% confidence interval: 1.0-1.5). In addition, those with either pre-transplant or post-transplant malignancies were associated with increased mortality risk. We suggest that a sufficient waiting period for patients with pre-transplant malignancies should be better emphasized to eliminate recurrence, and transplant tourists should be discouraged because of the possibility of higher post-transplant de novo malignancy occurrence and mortality.

Association of DNA methyltransferases 3A and 3B polymorphisms, and plasma folate levels with the risk of urothelial carcinoma

BACKGROUND

Interindividual genetic variations of human DNA methyltransferases (DNMTs), which involve the methyl donor from the folate-related one-carbon metabolism pathway, are hypothesized as a risk factor for urothelial carcinoma (UC). Therefore, we evaluated the role of gene-environment interaction in UC carcinogenesis.

METHODS

A hospital-based case-control study was conducted by recruiting 192 patients with UC and 381 controls. Their plasma folate levels were measured using a competitive immunoassay kit. In addition, DNMT3A -448A>G and DNMT3B -579G>T genotyping was evaluated using a polymerase chain reaction-restriction fragment length polymorphism technique. Multivariate logistic regression and 95% confidence intervals (CIs) were applied to estimate the UC risk.

RESULTS

We observed that patients with UC exhibited a higher prevalence rate of folate insufficiency (folate levels ≤6 ng/mL) compared with the controls (35.94% and 18.37%, respectively). Furthermore, folate levels were higher in the prevalent UC patients than in the incident UC patients. However, folate insufficiency was similarly associated with a nearly two-fold increase in the risk of UC regardless of the UC patient group. In addition, the frequencies of the variant alleles for DNMT3A and DNMT3B were 0.80 and 0.92, respectively, and no association was observed with UC risk. However, participants with a variant homozygous genotype of DNMT3B -579G>T and folate insufficiency or with high cumulative cigarette smoking exhibited an increased risk of UC.

CONCLUSION

Overall, environmental factors may contribute more significantly to UC carcinogenesis compared with genetic susceptibility. Future studies should investigate other polymorphisms of DNMT3A and DNMT3B to determine genetic susceptibility.

Increased risk of end-stage renal disease in patients with renal cell carcinoma: a 12-year nationwide follow-up study

The effect of renal cell carcinoma (RCC) on the risk for end-stage renal disease (ESRD) has not been confirmed. The present population-based study used the claims data from the Taiwan National Health Institutes from 1998 to 2010 to compare the risk for ESRD in patients with and without RCC.The study cohort consisted of 2940 patients who had newly diagnosed with RCC but no history of ESRD; the control cohort consisted of 23,520 matched patients without RCC. Cox proportional hazard regressions were performed to compute ESRD risk after adjusting for possible confounding factors. Kaplan-Meier analysis and the log-rank test were also used to compare patients and controls.A total of 119 patients in the RCC group (incidence rate: 119/2940; 4.05%) and 160 patients in the control group (incidence rate: 160/23,520; 0.68%) were diagnosed with ESRD during the follow-up period. After adjusting for potential confounders, the RCC group had an ESRD hazard ratio (HR) of 5.63 [95% confidence interval (CI): 4.37-7.24] relative to the control group. In addition, among patients with RCC, females (adjusted HR: 6.95, 95% CI: 4.82-10.1) had a higher risk for ESRD than males (adjusted HR: 4.79, 95% CI: 3.37-6.82). Finally, there were significant joint effects of chronic kidney disease and diabetes on increasing the risk of ESRD in patients with and without RCC (P < 0.01). The limitations of this study include the retrospective design and the inability to assess methods of treatment and measure the aggressiveness of RCC.Our data indicates that RCC is an independent risk factor for ESRD, especially in females.

Pharmacokinetics and preliminary safety data of a single oral dose of bosentan, a dual endothelin receptor antagonist, in cats

The objective of this study was to evaluate the pharmacokinetic properties and adverse effect profile of single-dose oral bosentan, a dual endothelin receptor antagonist, in healthy cats. Pharmacokinetic parameters were determined following a single mean ± SD oral dose of 3.2 ± 0.6 mg/kg of bosentan in 6 adult cats. Blood was collected for quantification of bosentan via high-performance liquid chromatography with ultraviolet detection. Blood and urine were evaluated for CBC, plasma biochemical profile, and urinalysis, and repeat physical examinations were performed to evaluate for adverse effects. The mean terminal half-life of bosentan was 20.4 ± 17.2 h. The mean peak plasma concentration was 0.49 ± 0.24 g/mL, and the mean time to maximum plasma concentration was 6.8 ± 8.6 h. The area under the curve was 5.14 ± 3.81 h·μg/mL. Oral bosentan tablets were absorbed in cats, and no clinically important adverse events were noted. Further evaluation of repeat dosing, investigation into the in vivo efficacy of decreasing endothelin-1 concentrations in cats, as well as safety in conjunction with other medications is warranted.

Spontaneous ureteral rupture and review of the literature

INTRODUCTION

Spontaneous ureteral rupture is defined as non-traumatic urinary leakage from the ureter. This is a diagnosis that, although uncommon, is important for emergency physicians to know about. The literature is relatively sparse.

MATERIALS AND METHODS

This was a retrospective review of patients who were diagnosed with spontaneous ureteral rupture. From 2006 to 2012, 18 patients were diagnosed by radiography (computed tomography or intravenous urogram) with spontaneous ureteral rupture. These cases all showed extravasation of the contrast outside the excretory system. We evaluated underlying causes, diagnostic and therapeutic procedures, and outcomes.

RESULTS

There were 9 men and 9 women with a median age of 59 years (range, 22-82 years). In 56% of patients, a ureteral stone was the cause; in 17% of, a ureteral stricture; in 1 patient, a ureteral tumor; and in the remaining 22%, no cause was identified. In 13 patients (72.2%), primary ureteroscopy to place D-J stents was performed. The average duration of ureteral catheter stenting was 21 days (range, 8-45 days). The other 5 patients (27.8%) were managed conservatively with antibiotic treatment and the outcome was good.

CONCLUSIONS

Ureteral stones most commonly cause spontaneous ureteral rupture. In our experience, most patients received ureteroscopy and Double-J stenting. Conservative management with antibiotics also had good outcomes. Most patients had sudden onset of abdominal or flank pain. Spontaneous ureteral rupture should be kept in the differential diagnosis of patients with acute abdominal or flank pain in the emergency department.

Exciton photoluminescence in resonant quasi-periodic Thue-Morse quantum wells

This Letter investigates exciton photoluminescence (PL) in resonant quasi-periodic Thue-Morse quantum wells (QWs). The results show that the PL properties of quasi-periodic Thue-Morse QWs are quite different from those of resonant Fibonacci QWs. The maximum and minimum PL intensities occur under the anti-Bragg and Bragg conditions, respectively. The maxima of the PL intensity gradually decline when the filling factor increases from 0.25 to 0.5. Accordingly, the squared electric field at the QWs decreases as the Thue-Morse QW deviates from the anti-Bragg condition.

DSBCS modulation scheme for hybrid wireless and cable television system

This work develops and demonstrates a double sideband with optical carrier suppression (DSBCS) modulation scheme for a hybrid wireless and cable television system based on a phase modulator (PM) and a polarization beam splitter (PBS). A carrier suppression ratio greater than 20 dB is achieved between two sidebands. In addition, the values of carrier-to-noise ratio, composite second-order and composite triple beat in various channels after 25 km of transmission are higher than the threshold value, and the power penalty of microwave signal in back-to-back and 25 km transmission perform well. Additionally, the constellation diagram of upstream signal is successfully recovered. Above results demonstrate that the proposed scheme is highly promising for practical applications.

Quasi-Bragg conditions in Thue-Morse dielectric multilayers

The existence of quasi-Bragg conditions (QBCs) in Thue-Morse dielectric multilayers (TMDMs), based on high reflectance and large forbidden gap regions in its transmission spectra, is presented. In contrast to a single traditional Bragg condition (TBC) in periodic bilayers, there are three QBCs in TMDMs. The formula for each of these QBCs is derived. The results show that one of these QBCs just overlaps the TBC. However, a singular point with perfect transmission exists in this QBC at the quarter-wave stack, at which high reflection exists in the periodic bilayers.

Strong photoluminescence emission from resonant Fibonacci quantum wells

Strong photoluminescence (PL) emission from a resonant Fibonacci quantum well (FQW) is demonstrated. The maximum PL intensity in the FQW is significantly stronger than that in a periodic QW under the Bragg or anti-Bragg conditions. Moreover, the peaks of the squared electric field in the FQW are located very near each of the QWs. The optimal PL spectrum in the FQW has an asymmetrical form rather than the symmetrical one in the periodic case. The maximum PL intensity and the corresponding thickness filling factor in the FQW become greater with increasing generation order.

The expression and actions of androgen receptor in upper urinary tract urothelial carcinoma (UUTUC) tissues and the primary cultured cells

Sex hormone receptors, androgen receptor (AR) and estrogen receptors (ERs) including both ERα and ERβ, mediate the actions of sex hormones. In this study, we aimed to evaluate sex hormone receptors expression in upper urinary tract urothelial carcinomas (UUTUCs) of ureter and renal pelvis with different tumor stages and grades as well as their possible roles in tumor progression. Immunohistochemistry was used to assay the expression of AR and ERs in the primary UUTUCs. XTT viability test was applied to evaluate cell responses for anticancer drug treatment. Wound healing assay was performed to determine cell migration abilities. AR and ERβ immunoreactivities were observed in both UUTUCs, but ERα was not detected in either UUTUCs. In UUTUC of ureter specimens, higher AR expression was found in superficial or lower grade tumors. In contrast, little difference of ERβ expression was found in superficial versus muscle-invasive tumor stages or low grades versus high grades in UUTUCs of ureter specimens. Furthermore in the primary cultured cells from UUTUC specimens, the addition of functional AR reduced cell chemosensitivity, but increased cell migration. These results provide the first data showing the expression patterns of sex hormone receptors in both renal pelvis and ureter UUTUCs. From results, we concluded that there is a positive correlation for higher AR expression found in superficial or low-grade UUTUCs of ureter and identified the functional roles of AR in UUTUC progression.

Sex differences in the development of malignancies among end-stage renal disease patients: a nationwide population-based follow-up study in Taiwan

Increasing evidence indicates that end-stage renal disease (ESRD) is associated with the morbidity of cancer. However, whether different dialysis modality and sex effect modify the cancer risks in ESRD patients remains unclear. A total of 3,570 newly diagnosed ESRD patients and 14,280 controls matched for age, sex, index month, and index year were recruited from the National Health Insurance Research Database in Taiwan. The ESRD status was ascertained from the registry of catastrophic illness patients. The incidence of cancer was identified through cross-referencing with the National Cancer Registry System. The Cox proportional hazards model and the Kaplan–Meier method were used for analyses. A similar twofold increase in cancer risk was observed among ESRD patients undergoing hemodialysis (HD) or peritoneal dialysis (PD) after adjusting for other potential risk factors. Patients with the highest cancer risk, approximately fourfold increased risk, were those received renal transplants. Urothelial carcinoma (UC) had the highest incidence in HD and PD patients. However, renal cell carcinoma (RCC) had the highest incidence in the renal transplantation (RT) group. In addition, female patients undergoing RT or PD had a higher incidence of RCC and UC, respectively. Male patients under HD had both higher incidence of RCC and UC. In conclusion, different dialysis modality could modify the cancer risks in ESRD patients. We also found sex effect on genitourinary malignancy when they are under different dialysis modality.

The role of XRCC6 T-991C functional polymorphism in renal cell carcinoma

BACKGROUND

The DNA non-homologous end-joining repair gene XRCC6 (Ku70) plays a key role in both the DNA double-strand break (DSB) repair and cell cycle arrest. Defects in DSB repair capacity can lead to genomic instability. We hypothesized that a variant in the XRCC6 gene was associated with susceptibility to renal cell carcinoma (RCC).

MATERIALS AND METHODS

In a hospital-based case-control study of 92 patients with RCC and 580 cancer-free controls, the frequency matched by age and sex, the associations of XRCC6 promoter T-991C (rs5751129), promoter G-57C (rs2267437), promoter A-31G (rs132770), and intron 3 (rs132774) polymorphisms with RCC risk were investigated in a Taiwanese population. At the same time, 30 adjacent renal tissue samples were tested to estimate the XRCC6 mRNA expression by real-time quantitative reverse transcription.

RESULTS

Compared with the TT genotype, the TC genotype had a significantly increased risk of RCC [adjusted odds ratio=2.24, 95% confidence interval=1.25-4.08, p=0.0175]. The in vivo mRNA expression in renal tissues revealed a statistically significant lower XRCC6 mRNA expression in samples with TC/CC genotypes compared to those with the TT genotype (p=0.0039).

CONCLUSION

These evidence suggests that the XRCC6 T-991C genotype together with its mRNA expression are involved in the etiology of RCC and may be a marker for susceptibility to RCC in the population of Taiwan.

Erosive potential of sports beverages

BACKGROUND

Dental erosion is an increasingly prevalent problem in Australia, with the consumption of sports beverages suggested as a risk factor. The aim of this study was to compare the erosive potential of Australian sports beverages.

METHODS

Ten beverages were selected and analysed to determine their pH, titratable acidity and apparent degree of saturation with respect to apatite. The erosive potential of the beverages was measured by human enamel surface loss and surface softening following a 30-minute exposure. A taste testing panel was established to determine the palatability of the sports beverages.

RESULTS

All sports beverages except Sukkie and Endura produced substantial surface loss and surface softening. Compared with the other sports beverages, Sukkie and Endura had a higher pH, lower titratable acidity and higher calcium content. However, Sukkie and Endura were deemed to be less palatable than the other more acidic sports beverages.

CONCLUSIONS

The majority of the sports beverages tested produced dental erosion in this in vitro model. However, two new products Sukkie and Endura have lower erosive potential but also lower palatability.

Differential effects of arsenic on calcium signaling in primary keratinocytes and malignant (HSC-1) cells

Arsenic is highly toxic to living cells, especially skin, and skin cancer is induced by drinking water containing arsenic. The molecular mechanisms of arsenic-induced cancer, however, are not well understood. To examine the initial processes in the development of arsenic-induced cancer, we analyzed calcium signaling at an early stage of arsenic treatment of human primary cells and compared the effects with those observed with arsenic treatment in carcinoma-derived cells. We found that arsenic inhibited inositol trisphosphate receptor (IP3R) function in the endoplasmic reticulum by inducing phosphorylation, which led to decreased intracellular calcium levels. Blockade of IP3R phosphorylation by the serine/threonine protein kinase Akt inhibitor wortmannin rescued calcium signaling. In contrast, arsenic treatment of cells derived from a carcinoma (human squamous carcinoma; HSC-1) for 1h had no obvious effect. Taken together, these results suggest that arsenic-induced reduction in calcium signaling is one of the initial mechanisms underlying the malignant transformation in the development of skin cancer.

The optimal effect site concentration of remifentanil in combination with intravenous midazolam and topical lidocaine for awake fibreoptic nasotracheal intubation in patients undergoing cervical spine surgery

BACKGROUND

Remifentanil has been suggested as a suitable agent for conscious sedation during fibreoptic intubation. We evaluated the optimal effect site concentration (Ce) of remifentanil target-controlled infusion (TCI) for awake nasotracheal fibreoptic intubation in patients undergoing elective cervical spine surgery.

METHODS

Nineteen ASA I-II patients were enrolled. Patients were premedicated with midazolam (<70 kg 1.5 mg; >70 kg 2.0 mg) intravenously. The EC(50) and EC(95) of remifentanil Ce for smooth intubation were determined using Dixon's up-and-down method and isotonic regression. Smooth intubation was considered to have failed when patients exhibited sustained and repetitive coughing with head lift during the procedure. Intubation time, number of attempts, adverse events, and hemodynamic variables were also recorded. Patients were asked to recall the procedure and grade satisfaction at postoperative 24 h.

RESULTS

The EC(50) of remifentanil Ce for smooth intubation was 2.33±0.38 ng·mL-1 as calculated by Dixon's method. The estimated EC(95) of remifentanil Ce was 3.38 (95% confidence interval 2.90-3.46) ng·mL-1. Median intubation time (min) was longer in failed smooth intubation than in smooth intubation (8.0 vs. 6.1, P=0.048). Eleven patients (58%) recalled the procedure and 16 patients (84%) rated their satisfaction score as good or excellent.

CONCLUSION

The estimated EC(95) of remifentanil Ce for smooth nasotracheal fibreoptic intubation with conscious sedation was 3.38 (95% CI 2.90-3.46) ng·mL-1 when used in combination with midazolam and topical lidocaine. Remifentanil TCI may provide a tolerable experience of awake fibreoptic intubation despite the high incidence of recall.