Characteristics, outcomes, facilitators and barriers for psychosocial interventions on inpatient mental health dementia wards: a systematic review

BACKGROUND

The National Institute for Health and Care Excellence guidelines state that psychosocial interventions should be the first line of treatment for people with dementia who are experiencing distress behaviours, such as agitation and depression. However, little is known about the characteristics and outcomes of psychosocial interventions or the facilitators and barriers to implementation on inpatient mental health dementia wards which provide care for people with dementia who are often experiencing high levels of distress.

METHODS

A systematic search was conducted on MEDLINE, CINAHL, PsycINFO, Psychology and Behavioural Sciences Collection, and Scopus in May 2023, following PRISMA guidelines. Reference and citation searches were conducted on included articles. Peer-reviewed literature of any study design, relating to psychosocial interventions in inpatient mental health dementia wards, was included. One author reviewed all articles, with a third of results reviewed independently by a second author. Data were extracted to a bespoke form and synthesised using a narrative review. The quality of included studies was appraised using the Mixed Methods Appraisal Tool.

RESULTS

Sixteen studies were included in the synthesis, which together included a total of 538 people with dementia. Study methods and quality varied. Psychosocial interventions delivered on wards included music therapy (five studies), multisensory interventions (four studies), multicomponent interventions (two studies), technology-based interventions (two studies), massage interventions (two studies) and physical exercise (one study). Reduction in distress and improvement in wellbeing was demonstrated inconsistently across studies. Delivering interventions in a caring and individualised way responding to patient need facilitated implementation. Lack of staff time and understanding of interventions, as well as high levels of staff turnover, were barriers to implementation.

CONCLUSION

This review highlights a striking lack of research and therefore evidence base for the use of psychosocial interventions to reduce distress in this vulnerable population, despite current healthcare guidelines. More research is needed to understand which psychosocial interventions can reduce distress and improve wellbeing on inpatient mental health dementia wards, and how interventions should be delivered, to establish clinical and cost effectiveness and minimise staff burden.

Administration of oral prednisolone to prevent esophageal stricture after balloon-type radiofrequency ablation for ultralong-segment esophageal neoplasia

BACKGROUND AND AIMS

Endoscopic radiofrequency ablation (RFA) has shown good efficacy and safety in eradicating flat-type early esophageal squamous cell neoplasia (ESCN). However, post-RFA stricture is still a major concern, especially when treating ultralong-segment ESCNs. The aim of this study was to investigate the efficacy and safety of oral prednisolone to prevent post-RFA stricture.

METHODS

We prospectively enrolled 48 patients treated with balloon-type RFA who had Lugol-unstained or mosaic-like flat-type ESCNs with an expected treatment area more than 10 cm. Oral prednisolone was started at a dose of 30 mg/day on the third day after RFA and continued for 4 weeks. The results were compared to a historical control group of 25 patients who received RFA without oral steroids. The primary endpoint was the frequency of post-RFA stricture. Secondary endpoints were the number of balloon dilation sessions and adverse event rate.

RESULTS

There were no significant differences in the worst pathology grade at baseline, length of unstained lesions between the two groups. The complete response rates after 1 session of RFA were 73% and 72%, respectively. Compared to the control group, the oral prednisolone group had a significantly lower stricture rate (4%, 2/48 patients vs. 44%, 11/25 patients; P<0.0001) and a lower number of balloon dilation sessions (median 0, range 0-4 vs. median 6, range 0-10). There were two cases of asymptomatic candida esophagitis in the study group, and no severe adverse effects.

CONCLUSIONS

Oral prednisolone may offer a useful and safe preventive option for post-RFA stricture in ultralong ESCNs.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05768282.

Analyzer-to-Analyzer Variations in Assaying Ultralow Concentrated Biomarkers Associated with Neurodegenerative Diseases Using Immunomagnetic Reduction

By utilizing a high-temperature superconducting quantum interference device (high-Tc SQUID) magnetometer, an alternating current (AC) magnetosusceptometer, referred to as an analyzer, was developed for ultrasensitive immunoassays. The analyzer has been applied to assay biomarkers in human plasma associated with Alzheimer's disease (AD) and Parkinson's disease (PD). The involved assay methodology is the so-called immunomagnetic reduction (IMR). Such an analyzer has been approved for clinical use in Taiwan and Europe. The mass production of the analyzer is needed for clinical utilities. The issue of exploring analyzer-to-analyzer variations in the performances becomes critical. Unfortunately, there is no standard characterization to determine the variations in performances among analyzers. In this study, key characterizations, such as output signal stability, signal-to-noise ratio, measured concentrations of a control sample, etc., are proposed. In total, three analyzers are characterized in this work. The detected biomarkers include amyloid peptides, total tau protein, phosphorylated tau protein, and α-synuclein protein for AD and PD. Through one-way ANOVA for any of the characterizations among the three analyzers, it was found that there was no significant difference in any of these characterizations among the analyzers (p > 0.05). Furthermore, the three analyzers are applied to assay biomolecules for AD and PD in reference samples. High correlations (r > 0.8) in measured concentrations of any of these biomarkers in reference samples were obtained among the three analyzers. The results demonstrate that the proposed characterizations are feasible for achieving consistent performance among high-Tc SQUID-based AC magnetosusceptometers for assaying biomolecules.

Recruitment approaches and profiles of consenting family caregivers and people living with dementia: A recruitment study within a trial

Background

While studies have identified strategies that are useful for recruiting people living with dementia, none have focused on psychosocial interventions involving arts therapies, or have examined the profiles of older people living in the community who consent or decline participation, particularly during a global pandemic. We aimed to identify the most effective recruitment strategies according to participant characteristics and transnational differences and develop a profile of consenting and non-consenting participants.

Methods

Recruitment teams in Australia, Norway, Germany, Poland, and the United Kingdom, recorded participants' source of study awareness and characteristics of consenting and non-consenting participants. Distributions of participants 'consenting to participate' were compared and logistic regressions were used to estimate the odds ratios.

Results

Consenting female caregivers were disproportionally represented. Study awareness differed between countries but overall, most expressions of interest to participate were derived from referrals from professionals or organisations, or from databases of people wanting to participate in research. Troughs in recruitment rates occurred during Northern Hemisphere summer vacation periods, and during Christmas periods.

Conclusions

This study found that recruiting for a trial with community-dwelling family caregivers and people living with dementia is challenging, especially during a global pandemic. While spousal caregivers comprised the highest proportion of dyads recruited, overall spousal caregivers were more reluctant to consent to participate than adult child caregivers. More targeted recruitment strategies designed for minority groups are also needed to ensure broader representation in dementia treatment studies.

Prognostic significance of systemic inflammatory response markers in patients with superficial esophageal squamous cell carcinomas

Endoscopic resection or esophagectomy has becoming the standard treatment for superficial esophageal squamous cell carcinomas (SESCC), but some patients may develop disease progression or second primary cancers after the therapies. Neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), and platelet to lymphocyte ratio (PLR) reflect the balance between pro-cancer inflammatory and anti-cancer immune responses, however their roles in SESCC are still unknown. We consecutively enrolled patients with newly diagnosed SESCC (clinical stage Tis or T1N0M0) who were treated at our institute. Pre-treatment NLR, LMR and PLR were assessed and then correlated with clinical factors and long-term survival. A total of 156 patients were enrolled (152 males, 4 females; median age: 52.2 years), of whom 104 received endoscopic resection and 52 were treated with esophagectomy or chemoradiation.. During a mean follow-up period of 60.1 months, seventeen patients died of ESCCs, and 45 died of second primary cancers. The 5-year ESCC-specific survival and 5-year overall survival rate were 86% and 57%, respectively. LMR (P < 0.05) and NLR (P < 0.05), but not PLR were significantly correlated with overall survival. Receiver operating characteristic curve analysis showed optimal LMR and NLR cut-off values of 4 and 2.5, respectively, to predict a poor prognosis. Patients with a high NLR or low LMR tended to have longer tumor length, larger circumferential extension, and presence of second primary cancers. Multivariate Cox regression analysis showed that presence of second primary cancers (HR: 5.05, 95%CI: 2.75-9.28), low LMR (HR: 2.56, 95%CI: 1.09-6.03) were independent risk factors for poor survival. A low pre-treatment LMR may be a non-invasive pretreatment predictor of poor prognosis to guide the surveillance program, suggesting that anti-cancer immunity may play a role in the early events of esophageal squamous cancer.

Development of a 36-Channel Instrument for Assaying Biomarkers of Ultralow Concentrations Utilizing Immunomagnetic Reduction

With the demands of the high-throughput assay of biomarkers of ultralow concentrations in clinics, a 36-channel instrument utilizing immunomagnetic reduction (IMR) has been developed. The instrument involves the use of a high-T _c superconducting-quantum-interference-device (SQUID) magnetometer to detect the signals due to the associations between target biomarker molecules and the antibody-functionalized magnetic nanoparticles in the reagent of IMR. In addition to illustrating the design and the measurements of the instrument, the assay characterizations for eight kinds of biomarkers related to neurodegenerative disease are investigated. Furthermore, the assay results among three independent instruments were compared. For an instrument, the channel-to-channel variations in measured concentrations of biomarkers are within a range of 2.09 to 5.62%. The assay accuracy was found to be from 99 to 103.7%. The p values in measured concentrations for any of the tested biomarkers were higher than 0.05 among the three instruments. The results demonstrate high throughput, high stability, and high consistency for the SQUID-IMR instruments.

Effect of Time to Detection on the Measured Concentrations of Blood Proteins Associated with Alzheimer’s Disease

Background

For assays using immunomagnetic reduction, a reagent composed of antibody-functionalized magnetic nanoparticles is dispersed in phosphate-buffered saline solution. The real-time signals of alternating-current (ac) magnetic susceptibility, χ_ac, of the reagent are subsequently recorded after mixing the reagent with a biofluid sample. After mixing the reagent and sample, the reduction in χ_ac of the mixture is calculated and used to quantify the concentration of the target biomarker in the sample. The reduction does not occur immediately but rather occurs at some time after mixing. This observation implies that the time elapsed before recording the real-time signals of χ_ac of a reagent-sample mixture needs to be investigated to ensure that the signals are fully recorded. In this work, the effect of time to detection on the measured concentrations of proteins in human plasma after mixing the reagent and sample is examined.

Methods

The proteins analyzed are related to Alzheimer's disease: amyloid β 1–40, amyloid β 1–42, and Tau protein. The investigated times to detection after the mixing the reagent and sample are 0, 20, 30, 40, and 120 min.

Results

The results show that the recording of real-time signals of χ_ac should be conducted within 20 min after mixing the reagent and sample.

Assessment of tumor extension to the ductal system of submucosal glands in patients with superficial esophageal squamous neoplasms: Implications for endoscopic resection

BACKGROUND

Endoscopic submucosal dissection (ESD) has become the standard treatment for superficial esophageal squamous cell neoplasia (SESCN); however, local recurrence still occurs occasionally even in patients who meet the current curative criteria. Esophageal ducts of the submucosal gland may serve as a pathway for the spread of SESCN to a deeper layer. However, the clinical impact of ductal involvement (DI) in patients undergoing ESD has yet to be investigated.

METHODS

We consecutively enrolled patients with SESCN who were treated with ESD. The resected specimens were meticulously reviewed in multiple section slices for the presence and resected margins of DI, and their correlations with clinical factors were evaluated.

RESULTS

A total of 210 lesions were analyzed, of which 78 (37.1%) presented with DI. The presence of submucosal invasion, lymphovascular invasion (LVI), and DI were indicators of worse prognosis (P < .05). Deep extended DIs were misdiagnosed as deep submucosal invasive cancer in 4 cases (2%). Of the 185 patients who met the criteria for curative ESD (ie, R0 resection and no deep submucosal invasion or LVI), 11 (5.9%) developed local recurrence/metastasis during a mean follow-up of 55.2 months (range, 6 to 140) months. Compared with patients with without DI, patients with DI had worse recurrence-free survival (P = .008, log-rank test) and a higher local risk of recurrence (12.7% vs 2.5%) after curative ESD (hazard ratio, 4.20; P = .038).

CONCLUSIONS

A precise histological assessment of DI in SESCN is crucial after ESD, given that DI is common and associated with worse outcome. Whether total removal of esophageal glands/ducts can improve outcome requires future study.

Long-term outcomes of endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma in Taiwan

Background

Endoscopic submucosal dissection (ESD) is gradually turning into the standard treatment for superficial esophageal squamous cell carcinoma (SESCC), however, the long-term outcomes have hardly ever been reported outside Japan.

Method

We consecutively recruited patients with SESCC who had received ESD treatment at E-Da Hospital. The demographics, pathological characteristics, and Lugol staining background pattern (type A or B: none or < 10 small Lugol-voiding lesions [LVLs]; type C or D: > 10 small or multiform LVLs) were collected, and then correlated to outcomes and survival.

Results

Total of 229 lesions were enrolled and the mean lesion size was 3.28 ± 1.69 (range 1–10) cm. 72% of the lesions had a type C-D Lugol staining background pattern. After ESD, the en bloc and R0 resection rates were 93.9% and 83.5%, respectively. Forty-nine subjects developed complications, including six (2.6%) with major bleeding, two (0.9%) with perforation, and 41 (17.9%) with strictures. Pathological staging showed that 19 cases had deep submucosal cancer invasion and subsequently received adjuvant therapies. During a mean follow-up period of 52.6 (range 3–146) months, 41 patients developed metachronous recurrence. The patients with a type C-D Lugol staining background pattern were associated with a higher risk of recurrence than those with few LVLs (log-rank P = 0.019). The 10-year survival rate was more than 90%, and only eight patients died of ESCC.

Conclusion

ESD has excellent long-term outcomes but a high risk of metachronous recurrence. The Lugol staining pattern over the background mucosa could offer the risk stratification of metachronous recurrence.

A clinically interpretable convolutional neural network for the real-time prediction of early squamous cell cancer of the esophagus: comparing diagnostic performance with a panel of expert European and Asian endoscopists

BACKGROUND AND AIMS

Intrapapillary capillary loops (IPCLs) are microvascular structures that correlate with the invasion depth of early squamous cell neoplasia and allow accurate prediction of histology. Artificial intelligence may improve human recognition of IPCL patterns and prediction of histology to allow prompt access to endoscopic therapy for early squamous cell neoplasia where appropriate.

METHODS

One hundred fifteen patients were recruited at 2 academic Taiwanese hospitals. Magnification endoscopy narrow-band imaging videos of squamous mucosa were labeled as dysplastic or normal according to their histology, and IPCL patterns were classified by consensus of 3 experienced clinicians. A convolutional neural network (CNN) was trained to classify IPCLs, using 67,742 high-quality magnification endoscopy narrow-band images by 5-fold cross validation. Performance measures were calculated to give an average F1 score, accuracy, sensitivity, and specificity. A panel of 5 Asian and 4 European experts predicted the histology of a random selection of 158 images using the Japanese Endoscopic Society IPCL classification; accuracy, sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

Expert European Union (EU) and Asian endoscopists attained F1 scores (a measure of binary classification accuracy) of 97.0% and 98%, respectively. Sensitivity and accuracy of the EU and Asian clinicians were 97%, 98% and 96.9%, 97.1%, respectively. The CNN average F1 score was 94%, sensitivity 93.7%, and accuracy 91.7%. Our CNN operates at video rate and generates class activation maps that can be used to visually validate CNN predictions.

CONCLUSIONS

We report a clinically interpretable CNN developed to predict histology based on IPCL patterns, in real time, using the largest reported dataset of images for this purpose. Our CNN achieved diagnostic performance comparable with an expert panel of endoscopists.

A Novel Routing Algorithm for the Acceleration of Flow Scheduling in Time-Sensitive Networks

IEEE Time-Sensitive Networking (TSN) Task Group specifies a series of standards such as 802.1Qbv for enhancing the management of time-critical flows in real-time networks. Under the IEEE 802.1Qbv standard, the scheduling algorithm is employed to determine the time when a specific gate in the network entities is opened or closed so that the real-time requirements for the flows are guaranteed. The computation time of this scheduling algorithm is critical for the system where dynamic network configurations and settings are required. In addition, the network routing where the paths of the flows are determined has a significant impact on the computation time of the network scheduling. This paper presents a novel scheduling-aware routing algorithm to minimize the computation time of the scheduling algorithm in network management. The proposed routing algorithm determines the path for each time-triggered flow by including the consideration of the period of the flow. This decreases the occurrence of path-conflict during the stage of network scheduling. The detailed outline of the proposed algorithm is presented in this paper. The experimental results show that the proposed routing algorithm reduces the computation time of network scheduling by up to 30% and improves the schedulability of time-triggered flows is the network.

Long-term outcomes of endoscopic submucosal dissection and comparison to surgery for superficial esophageal squamous cancer: a systematic review and meta-analysis

AIM

The aim of this study was to investigate the long-term outcomes of endoscopic submucosal dissection (ESD) for superficial esophageal squamous cancer.

METHODS

A literature search was conducted using PubMed, ProQuest and Cochrane Library databases. Primary outcomes were overall survival, disease-specific survival and recurrence-free survival at 5 years. Secondary outcomes included adverse events, recurrence and metastasis. Hazard ratios were calculated based on time to events for survival analysis, and odds radios were used to compare discrete variables.

RESULTS

A total of 3796 patients in 21 retrospective studies, including 5 comparative studies for ESD and esophagectomy were enrolled. The invasion depth was 52.0% for M1-M2, 43.2% for M3-SM1 and 4.7% for SM2 or deeper. The 5-year survival rate was: overall survival 87.3%, disease-specific survival 97.7%, and recurrence-free survival 85.1%, respectively. Pooled local recurrence of ESD was 1.8% and metastasis was 3.3%. In terms of the comparison between ESD and esophagectomy, there was no difference in the overall survival (86.4% versus 81.8%, hazard ratio = 0.66, 95% CI = 0.39-1.11) as well as disease-specific and recurrence-free survival. In addition, ESD was associated with fewer adverse events (19.8 % versus 44.0%, odds ratio = 0.3, 95% CI = 0.23-0.39).

CONCLUSIONS

For superficial esophageal squamous cancer, ESD may be considered as the primary treatment of for mucosal lesions, and additional treatment should be available for submucosal invasive cancers.

Risk factors and pathological characteristics for intraductal tumor spread of submucosal gland in early esophageal squamous cell neoplasia

The esophageal gland duct may serve as a pathway for the spread of early esophageal squamous cell neoplasia (ESCN) to a deeper layer. Deep intraductal tumor spreading cannot be completely eradicated by ablation therapy. However, the risk factors of ductal involvement (DI) in patients with ESCNs have yet to be investigated. We consecutively enrolled 160 early ESCNs, which were treated with endoscopic submucosal dissection. The resected specimens were reviewed for the number, morphology, resected margin, distribution and extension level of DI, which were then correlated to clinical factors. A total of 317 DIs (median:3, range 1-40 per-lesion) in 61 lesions (38.1%) were identified. Of these lesions, 14 have DIs maximally extended to the level of lamina propria mucosa, 17 to muscularis mucosae, and 30 to the submucosa. Multivariate logistic regression analysis showed that tumors located in the upper esophagus (OR = 2.93, 95% CI, 1.02-8.42), large tumor circumferential extension (OR = 5.39, 95% CI, 1.06-27.47), deep tumor invasion depth (OR = 4.12, 95% CI, 1.81-9.33) and numerous Lugol-voiding lesions in background esophageal mucosa (OR = 2.65, 95% CI, 1.10-6.37) were risk factors for DI. The maximally extended level of ducts involved were significantly correlated with the cancer invasion depth (P < 0.05). Notably, 245 (77%) of the involved ducts were located at the central-trisection of the lesions, and 52% of them (165/317) revealed dilatation of esophageal glandular ducts. Five (1.6%) of the involved ducts revealed cancer cell invasion through the glandular structures. In conclusion, DI is not uncommon in early ESCN and may be a major limitation of endoscopic ablation therapy.

Sleep apnea assessment using declination duration-based global metrics from unobtrusive fiber optic sensors

OBJECTIVE

Sufficient sleep helps to restore the immune, nervous and cardiovascular systems, but is sometimes disturbed by sleep apnea (SA). The early diagnosis of sleep apnea is beneficial for the prevention of diseases. Polysomnography (PSG) recording provides comprehensive data for such assessment, but is not suitable for use at home due to discomfort during measurement and the difficulty of identification. This study proposes an unobtrusive measurement process by placing fiber optic sensors (FOSs) in a pillow (head-neck) or a bed mattress (thoracic-dorsal).

APPROACH

We test two approaches: drop degrees from the baseline to validate the capability of catching respiratory drops, and linear regression models based on a new global measure, the percentage of the total duration of respiratory declination (PTDRD), to estimate the hand-scored apnea/hypopnea index (AHI).

MAIN RESULTS

Based on data recorded from 63 adults, the drop degrees derived from respiratory signals exhibited statistical differences among central sleep apnea (CSA), obstructive sleep apnea (OSA) and normal breathing. The regression models based on the PTDRDs derived from head-neck FOS and thoracic-dorsal FOS also achieved good agreement with manually scored AHIs in Bland-Altman plots as well as oronasal airflow and thoracic wall movement.

SIGNIFICANCE

The aforementioned performance demonstrates the capability of the FOS measurement and the efficacy of the PTDRD metrics for SA assessment.

The benefit of adding oral simethicone in bowel preparation regimen for the detection of colon adenoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Simethicone is an anti-foaming agent commonly used during colonoscopy. Although several randomized trials have shown that oral simethicone in the bowel preparation regimen may improve bowel cleanness, whether it improves adenoma detection rate (ADR) or polyp detection rate remains undetermined. The aim of this study was to determine if oral simethicone in bowel preparation regimen before colonoscopy improves the ADR.

METHODS

A comprehensive literature review was conducted using PubMed, SDOL, Cochrane Library, and ProQuest databases through December 2017. Randomized controlled trials that compared bowel preparation regimens with simethicone versus those without it were included. Effect estimates from each study were extracted and underwent meta-analysis using appropriate models. The primary outcomes were ADR and polyp detection rate, and secondary outcomes included bowel preparation, bubble score, and withdrawal time.

RESULTS

Twelve published randomized controlled studies with 6003 participants were included for meta-analysis. There was no difference in the overall ADR (pooled risk ratio = 1.06, 95% confidence interval = 0.91-1.24) and right-side ADR (risk ratio = 1.50, 95% confidence interval = 0.82-2.75) between the groups with or without simethicone. However, the addition of simethicone improved adenoma detected per patient (2.20 ± 1.36 vs 1.63 ± 0.89) according to one of the included studies. Meta-regression revealed that the baseline ADR < 25% of the included studies was associated with significant benefit of oral simethicone; the number needed to treat was 15.

CONCLUSIONS

The adjunction of oral simethicone significantly improved bowel preparation quality and might benefit adenoma detection in specific settings with low baseline ADR.

Threshold-based fall detection using a hybrid of tri-axial accelerometer and gyroscope

OBJECTIVE

Falling is an important health maintenance issue for the elderly and people with movement disorders, strokes and multiple sclerosis. With the development of light, low-cost wearable technology, inertia-based fall detection has gained much attention. However, some large movements, such as jumping and postural changes, are frequently confounded with falls. For example, commonly used fall detection methods based on acceleration amplitude produce a large number of false alerts unless they are combined with post-fall posture identification. In this paper, we propose two new inertial parameters to improve the selectivity of threshold-based fall detection methods, and evaluate strategies to distinguish falls from other activities of daily life (ADLs).

APPROACH

We define two new inertial parameters, acceleration cubic-product-root magnitude (ACM) and angular velocity cubic-product-root magnitude (AVCM). Along with acceleration magnitude (AM), we test threshold-based fall detection methods based on single parameters and combinations. We collected inertial data on four types of simulated falls and eight types of ADLs from a study with 15 participants wearing a chest-mounted sensor with accelerometer and gyroscope. Two public datasets, UMAFall and Cognent Labs, were also included to evaluate fall detection methods.

MAIN RESULTS

We chose the detection threshold with 99% sensitivity and the best possible specificity. The hybrid of AM, ACM and AVCM method had a lower rate of misclassification than single-parameter methods. Leave-one-out cross-validation shows that the hybrid fall detection method can achieve both high specificity and high sensitivity.

SIGNIFICANCE

Using multiple inertial parameters improves the specificity of fall detection.

Fabrication of Zinc Oxide-Based Thin-Film Transistors by Radio Frequency Sputtering for Ultraviolet Sensing Applications

In this study, zinc indium tin oxide thin-film transistors (ZITO TFTs) were fabricated by the radio frequency (RF) sputtering deposition method. Adding indium cations to ZnO by co-sputtering allows the development of ZITO TFTs with improved performance. Material characterization revealed that ZITO TFTs have a threshold voltage of 0.9 V, a subthreshold swing of 0.294 V/decade, a field-effect mobility of 5.32 cm2/Vs, and an on-off ratio of 4.7 × 105. Furthermore, an investigation of the photosensitivity of the fabricated devices was conducted by an illumination test. The responsivity of ZITO TFTs was 26 mA/W, with 330-nm illumination and a gate bias of -1 V. The UV-to-visible rejection ratio for ZITO TFTs was 2706. ZITO TFTs were observed to have greater UV light sensitivity than that of ZnO TFTs. We believe that these results suggest a significant step toward achieving high photosensitivity. In addition, the ZITO semiconductor system could be a promising candidate for use in high performance transparent TFTs, as well as further sensing applications.

Oxygen Partial Pressure Impact on Characteristics of Indium Titanium Zinc Oxide Thin Film Transistor Fabricated via RF Sputtering

Indium titanium zinc oxide (InTiZnO) as the channel layer in thin film transistor (TFT) grown by RF sputtering system is proposed in this work. Optical and electrical properties were investigated. By changing the oxygen flow ratio, we can suppress excess and undesirable oxygen-related defects to some extent, making it possible to fabricate the optimized device. XPS patterns for O 1s of InTiZnO thin films indicated that the amount of oxygen vacancy was apparently declined with the increasing oxygen flow ratio. The fabricated TFTs showed a threshold voltage of −0.9 V, mobility of 0.884 cm²/Vs, on-off ratio of 5.5 × 10⁵, and subthreshold swing of 0.41 V/dec.

Oblique electron-beam evaporation of distinctive indium-tin-oxide nanorods for enhanced light extraction from InGaN/GaN light emitting diodes

This paper presents a novel and mass-producible technique to fabricate indium-tin-oxide (ITO) nanorods which serve as an omnidirectional transparent conductive layer (TCL) for InGaN/GaN light emitting diodes (LEDs). The characteristic nanorods, prepared by oblique electron-beam evaporation in a nitrogen ambient, demonstrate high optical transmittance (T>90%) for the wavelength range of 450nm to 900nm. The light output power of a packaged InGaN/GaN LED with the incorporated nanorod layer is increased by 35.1% at an injection current of 350mA, compared to that of a conventional LED. Calculations based on a finite difference time domain (FDTD) method suggest that the extraction enhancement factor can be further improved by increasing the thickness of the nanorod layer, indicating great potential to enhance the luminous intensity of solid-state lighting devices using ITO nanorod structures.

Organic compound distribution between nonionic surfactant solution and natural solids: applicability of a solution property parameter

A solution property parameter phi was defined to examine the distribution characteristics of organic compounds between the solids and four nonionic surfactant solutions. The studied compounds consisted of BTEX (benzene, toluene, ethylbenzene, and p-xylene) and chlorinated pesticides (lindane, alpha-BHC, and heptachlor epoxide), which span several orders of magnitude in terms of water solubility (Sw). The solid samples were composed of a very low organic matter clay (Ca-montmorillonite), and a high organic matter natural soil (Shamou Mountain soil). The surfactants tested included two alkyl chain surfactants and two containing aromatic group surfactants with added concentrations both below and above their critical micelle concentration (CMC). By observing the Kom or Ksf variation, the result indicates, besides the Sw of the organic compounds, the distribution coefficient is regarded as a function of the soil organic matter (SOM) constituents, and the chemical structure of the organic compounds. Also, it can be found the greater phi values represent the higher releasing ratios of the organic compounds from the contaminated soil to groundwater. For the relatively higher Sw compounds, such as BTEX, all of the phi values are close to 1. The phi values for the relatively lower Sw compounds are far greater than 1, and increase with the increasing affinity of the compounds to the surfactants.

An integrated inundation model for highly developed urban areas

A numerical model is developed in this study with various components for simulating the complex flow phenomena in urban drainage basins. The model integrates the HEC-1 model, a 1-D dynamic channel-flow model, a 2-D non-inertia overland-flow model and the SWMM model to reflect the hydraulic processes in areas with different characteristics. The inundation of underground infrastructure during flood is also considered in the model. The typhoon Nari event in 2001, which resulted in severe flood in downtown Taipei, is simulated by the model. The result is compared with the survey records of flooded areas, which reveals the storage effect of underground infrastrucures is significant to the simulation results of highly developed urban areas.

The effect of surfactants on the distribution of organic compounds in the soil solid/water system

The efficiency of soil remediation by surfactant washing was evaluated via the measured distribution coefficients of a number of nonpolar compounds in several soil-water mixtures. The studied compounds (contaminants) are BTEX (benzene, toluene, ethylbenzene, and p-xylene) and three chlorinated pesticides (lindane, alpha-BHC, and heptachlor epoxide), which span several orders of magnitude in water solubility (S(w)). A peat, and two natural soils were used that comprise a wide range in soil organic matter (SOM) content. The surfactants tested included cationic, anionic and nonionic types, with concentrations up to five to six times the critical micelle concentration (CMC). The K(d)(*)/K(d), values were used to evaluate the remediation efficiency under various operation conditions. For relatively water soluble BTEX compounds, the surfactant adsorption on the soil surface is the deciding factor on contaminant desorption from soil. For the less-soluble pesticides, surfactant micelles in solution influence the contaminant desorption more. The contaminants partitioning to SOM or adsorbed surfactants lowers the desorption efficiency. Anionic surfactants are found to be a better choice on soil remediation because they do not form admicelle on soil surface that enhances the SOM content. Cationic surfactant, which adsorb onto soil surfaces, leads to poor remediation efficiency. An improper selection of surfactant would result in inefficiency in soil remediation by surfactant washing.

Predicting cranial computed tomography results of head injury patients using an artificial neural network

We conducted this study to determine if artificial neural network modeling would predict cranial computed tomography results in head injury patients using different combinations of clinical variables. 150 consecutive patients admitted to a regional trauma center with head injury were enrolled in the study. The CT was labeled with presence of surgically significant intracranial hematoma (SSIH), if midline shift, obliteration of ambient cistern or basal cistern were found. The best performance of our models to differentiate normal from abnormal cranial CT and detection of SSIH was ideal.

Consumption of flea faeces and eggs by larvae of the cat flea, Ctenocephalides felis

The effects of the consumption of flea faeces and non-viable eggs on larval development in the cat flea Ctenocephalides felis (Bouché) (Siphonaptera: Pulicidae) were investigated. Only 13.3% of larvae developed into adults when fed a diet of male or female flea faeces alone; however, 90% of larvae developed into adults when fed on flea faeces supplemented with non-viable flea eggs. When fed with non-viable eggs alone, larvae did not develop into adults. Nevertheless, non-viable eggs may provide critical supplemental nutrients, lacking in flea faeces and required for larval development. None of the larvae fed on flea faeces or non-viable eggs alone formed a cocoon. A diet of flea faeces alone significantly extended the second as well as third larval stadia compared to larvae fed on diets containing non-viable eggs. It is suggested that the cannibalism of fertile eggs may limit population growth in the cat flea.

Sonographic features of xanthogranulomatous pyelonephritis

PURPOSE

The purpose of this study was to describe the various sonographic features of xanthogranulomatous pyelonephritis (XGP).

METHODS

We retrospectively reviewed the CT, sonographic, and medical records of patients diagnosed with XGP from January 1981 to December 1998. Twenty-seven patients for whom XGP was histopathologically confirmed were included in the study. There were 12 men and 15 women, with an age range of 21-86 years (mean, 57 years). All patients had undergone sonography of the kidneys. The renal size, shape, and outline were recorded. The presence of perinephric fluid accumulation, of obstructive uropathy, or of internal echoes in the dilated collecting system and the echotexture of the renal parenchyma were documented.

RESULTS

We categorized the XGP into 4 groups on the basis of the sonographic features: (1) diffuse hydronephrotic, 12 patients (44%); (2) diffuse parenchymal, 9 patients (33%); (3) diffuse contracted, 4 patients (15%); and (4) segmental or focal, 2 patients (7%). A localized perinephric fluid collection was present in 4 patients (15%). The preoperative sonographic diagnoses were pyonephrosis (n = 14, 52%), renal pelvic tumor with possible associated infection (n = 5, 19%), renal parenchymal mass (n = 2, 7%), hydronephrosis (n = 2, 7%), and chronic pyelonephritis with renal atrophy (n = 4, 15%). XGP was considered a possible diagnosis in only 11 patients (41%).

CONCLUSIONS

XGP has no specific sonographic features but is suggested by parenchymal thinning and hydronephrosis, sonographic signs of chronic obstructive uropathy caused by stones; echoes in the dilated collecting system; and a perinephric fluid collection. CT, needle biopsy, or both are recommended to further evaluate and confirm sonographically suspected XGP.

Identification of peroxisome proliferator-responsive human genes by elevated expression of the peroxisome proliferator-activated receptor alpha in HepG2 cells

In mice and other sensitive species, PPARalpha mediates the induction of mitochondrial, microsomal, and peroxisomal fatty acid oxidation, peroxisome proliferation, liver enlargement, and tumors by peroxisome proliferators. In order to identify PPARalpha-responsive human genes, HepG2 cells were engineered to express PPARalpha at concentrations similar to mouse liver. This resulted in the dramatic induction of mRNAs encoding the mitochondrial HMG-CoA synthase and increases in fatty acyl-CoA synthetase (3-8-fold) and carnitine palmitoyl-CoA transferase IA (2-4-fold) mRNAs that were dependent on PPARalpha expression and enhanced by exposure to the PPARalpha agonist Wy14643. A PPAR response element was identified in the proximal promoter of the human HMG-CoA synthase gene that is functional in its native context. These data suggest that humans retain a capacity for PPARalpha regulation of mitochondrial fatty acid oxidation and ketogenesis. Human liver is refractory to peroxisome proliferation, and increased expression of mRNAs for the peroxisomal fatty acyl-CoA oxidase, bifunctional enzyme, or thiolase, which accompanies peroxisome proliferation in responsive species, was not evident following Wy14643 treatment of cells expressing elevated levels of PPARalpha. Additionally, no significant differences were seen for the expression of apolipoprotein AI, AII, or CIII; medium chain acyl-CoA dehydrogenase; or stearoyl-CoA desaturase mRNAs.

Evidence for direct protein kinase-C mediated modulation of N-methyl-D-aspartate receptor current

Protein kinase-C (PKC) activation differentially affects currents from N-methyl-D-aspartate (NMDA) type glutamate receptors depending upon their subunit composition. Experiments using chimeras initially indicated that the cytoplasmic C-terminal tails of NR2B (responsive to PKC) and NR2C (unresponsive to PKC) subunits contain the amino acid residues responsible for the observed disparity of PKC effects. However, truncation and point mutation experiments have suggested that PKC action on NMDA receptors may be entirely indirect, working via the phosphorylation of associated proteins. Here we suggest that PKC does, in fact, affect NR2B/NR1-011 NMDA currents by direct phosphorylation of the NR2B tail at residues S1303 and S1323. Replacement of either of these residues with Ala severely reduces PKC potentiation. To verify that S1303 and S1323 are sites of direct phosphorylation by PKC, synthetic peptides from the regions surrounding these sites were used as substrates for in vitro assays with purified rat brain PKC. These results indicate that PKC can directly phosphorylate S1303 and S1323 in the NR2B C terminus, leading to enhanced currents through NMDA receptor channels. The direct action of PKC on certain NMDA receptor subtypes may be important in any physiological or pathological process where PKC and NR2B/NR1 receptors interact.

A modeling study of water quality in main channel and estuarine wetland

A simple computation framework is applied to include estuarine wetland and their interaction with main channels in estuarine modeling. The concept and the model implementation of the scheme are explained using a vertical two-dimensional model of estuarine hydrodynamics and water quality. The model was applied to the Tanshui River estuary and Kuan-Du wetland. The model is calibrated and verified by the available measured data. Simulations are also conducted for various upstream freshwater discharges to predict water quality in the main channel and estuarine wetland. The results show that the inclusion of estuarine wetland in a water-quality model not only provides a framework for computing water-quality conditions but also accounts for the interaction between wetland and main channel. The model provides a useful tool for environmental planning, protection and proposed wetland restoration works.

Off-host observations of mating and postmating behaviors in the cat flea (Siphonaptera: Pulicidae)

A blood meal was necessary for a male cat flea, Ctenocephalides felis (Bouché), to display the mating attempts to an unfed or fed female. More mating pairs resulted when both sexes were fed. Copulation occurred when fed fleas were placed on surfaces with temperatures from 34 to 42 degrees C. This article not only describes the mating and postmating behaviors of cat fleas, but also compares them with those of other fleas. The sequence of mating behavior began when a male approached a female ventrally, and the male's antennae and claspers became erect to attach to the abdomen of the female. Clasper attachment lasted until copulation ended, whereas the male retrieved his antennae immediately after genitalia linkage. The male generally grasped the female's tarsi with his claws during mating. The length of the mating interval terminated by the male ranged from 25 to 110 min and was significantly longer than that terminated by the female (averaging 12.11 min). After the mating pair separated, the male displayed a series of postmating behaviors discussed herein. This article documents grasping and postmating behaviors of the male cat flea.

Autocrine regulation of interleukin-8 production in human monocytes

Interleukin (IL)-8 is a C-X-C chemokine that plays an important role in acute inflammation through its G protein-coupled receptors CXCR1 and CXCR2. In this study, we investigated the role of IL-8 as an autocrine regulator of IL-8 production and the signaling mechanisms involved in human peripheral blood mononuclear cells (MNCs). Sepharose-immobilized IL-8 stimulated a sevenfold increase in IL-8 production within 2 h. IL-8 induced the expression of its own message, and IL-8 biosynthesis was inhibited by cycloheximide and actinomycin D, indicating de novo RNA and protein synthesis. In contrast to MNCs, polymorphonuclear neutrophils did not respond to the immobilized IL-8 with IL-8 production despite cell surface expression of CXCR1 and CXCR2. Melanoma growth-stimulatory activity/growth-related protein-alpha (MGSA/GROalpha), which binds CXCR2 but not CXCR1, was unable to either stimulate IL-8 secretion in MNCs or desensitize these cells to respond to immobilized IL-8. The involvement of mitogen-activated protein kinase (MAPK) in IL-8-induced IL-8 biosynthesis was suggested by the ability of PD-98059, an inhibitor of MAPK kinase, to block this function. Furthermore, IL-8 induced a significant increase in extracellular signal-regulated kinase 2 phosphorylation, whereas MGSA/GROalpha was much less effective. These findings support the role of IL-8 as an autocrine regulator of IL-8 production and suggest that this function is mediated by CXCR1 through activation of MAPK.

Effects of multiple mating on female reproductive output in the cat flea (Siphonaptera: Pulicidae)

Multiple mating behavior of female cat fleas, Ctenocephalides felis (Bouché), was confirmed in this study, and its effects on fecundity and fertility were investigated as well. The number of fertile eggs produced by mated females was close to nil within 7 d after removal of males, but it was resumed when females were exposed to males again on day 7. Multiple-mated females displayed significantly higher fecundity (400.3 eggs per female) and fertility (182.8 viable eggs per female) than single-mated females (61.7 and 19.0, respectively) in the 24-d period, suggesting that multiple mating by females is an advantageous strategy for cat fleas. The duration of first mating averaged 63.1 min. The high ratio (55.56%) and short duration (34.0 min) of impotent mating suggested that cryptic female choice may be involved during copulation.

NF-kappaB activation is required for C5a-induced interleukin-8 gene expression in mononuclear cells

C5a, a potent peptide chemoattractant, stimulates interleukin-8 (IL-8) secretion from peripheral blood mononuclear cells (PBMC). Experiments were conducted to understand the mechanisms for C5a-induced IL-8 production, which was 14-fold greater than that in unstimulated cells by 2 hours. IL-8 secretion was accompanied by accumulation of IL-8 mRNA in the cytosol and by nuclear expression of a kappaB DNA binding activity within 30 minutes. AP-1 but not NF-IL-6 DNA binding activity was also detected in C5a-stimulated PBMC; however, its delayed expression (maximal at 4 hours) suggested a less important role in the rapid production of IL-8. The correlation between C5a-induced kappaB binding activity and IL-8 gene expression was examined in the RAW264.7 macrophage cells using reporter genes directed by the kappaB sequence from IkappaBalpha and IL-8 promoter regions. C5a-induced reporter gene expression was abolished by introducing mutations into the kappaB sites and by coexpression of a dominant negative IkappaBalpha construct resistant to agonist-induced phosphorylation. Pertussis toxin, which ADP-ribosylates the Gi proteins known to couple to the C5a receptor, produced minimal inhibition of C5a-induced IL-8 expression and had little effect on C5a-induced calcium mobilization in RAW264.7 cells. These results suggest that NF-kappaB activation is required for C5a-induced IL-8 gene expression and that this response is mediated primarily through a pertussis toxin-insensitive pathway.

A carboxyl-terminal extension of the zinc finger domain contributes to the specificity and polarity of peroxisome proliferator-activated receptor DNA binding

Heterodimers of the peroxisome proliferator-activated receptors (PPAR) and the retinoid X receptors (RXR) recognize response elements (PPREs) that exhibit the consensus sequence 5'-A(A/T)CT(A/G)GGNCAAAG(G/T)TCA-3'. The consensus PPRE includes both a 5'-extension and a direct repeat (DR1) comprised of two canonical core recognition sequences (underlined) for nuclear receptor zinc fingers separated by a single nucleotide spacer. The extended binding site recognized by PPARs is very similar to sites that bind monomers of the nuclear receptors Rev-ErbA and ROR suggesting that the latter could bind to PPREs and affect gene transcription. However, Rev-ErbA and ROR bind weakly to naturally occurring PPREs relative to the consensus binding site, and significant effects on PPARalpha transactivation of a CYP4A6-Z reporter were not observed. In contrast, PPAR/RXR heterodimers bind to a DR2 element containing the conserved 5'-extended sequence that is recognized by dimers of RORalpha or Rev-ErbA. PPARalpha/RXRalpha positively regulate transcription from this element, and co-expression of Rev-ErbA blocks this effect. The nuclear receptors NGFI-B and ROR utilize a carboxyl-terminal extension (CTE) of the zinc finger DNA binding domain in their interactions with the 5'-extension of a single zinc finger-binding site. DNA binding domains (DBD) of PPARs alpha, delta, and gamma that contain the zinc finger motif and a CTE display binding to core recognition sequences that is dependent on the 5'-extended sequence found in PPREs. Unlike DBDs of other nuclear receptors that form heterodimers with RXR, the PPAR-DBDs did not exhibit cooperative binding with the DBD of RXR and exhibit the opposite polarity for binding to the direct repeat motif. In contrast to the corresponding DBD of RXR, the PPAR-DBDs bind as monomers to a single extended binding site as well as to the consensus PPRE. A chimera linking the zinc finger domain of RXRalpha to the CTE from PPARalpha bound to a single extended binding site indicating a functional role for the CTE of PPARs in extended binding site recognition.

Identification of thyroid hormone response elements in the human fatty acid synthase promoter

To investigate the regulation of the human fatty acid synthase gene by the thyroid hormone triiodothyronine, various constructs of the human fatty acid synthase promoter and the luciferase reporter gene were transfected in combination with plasmids expressing the thyroid hormone and the retinoid X receptors in HepG2 cells. The reporter gene was activated 25-fold by the thyroid hormone in the presence of the thyroid hormone receptor. When both the thyroid hormone and the retinoid X receptors were expressed in HepG2 cells, there was about a 100-fold increase in reporter gene expression. 5'-Deletion analysis disclosed two thyroid hormone response elements, TRE1 (nucleotides -870 to -650) and TRE2 (nucleotides -272 to -40), in the human fatty acid synthase promoter. The presence of thyroid hormone response elements in these two regions of the promoter was confirmed by cloning various fragments of these two regions in the minimal thymidine kinase promoter-luciferase reporter gene plasmid construct and determining reporter gene expression. The results of this cloning procedure and those of electrophoretic mobility shift assays indicated that the sequence GGGTTAcgtcCGGTCA (nucleotides -716 to -731) represents TRE1 and that the sequence GGGTCC (nucleotides -117 to -112) represents TRE2. The sequence of TRE1 is very similar to the consensus sequence of the thyroid hormone response element, whereas the sequence of TRE2 contains only a half-site of the thyroid hormone response element consensus motif because it lacks the direct repeat. The sequences on either side of TRE2 seem to influence its response to the thyroid hormone and retinoid X receptors.

Cloning and functional characterization of the mouse C3a anaphylatoxin receptor gene

The mouse anaphylatoxin C3a receptor (mC3aR) gene was isolated using a human C3aR cDNA probe. The genomic fragment contains an open reading frame of 1431 base pairs that encodes a peptide of 477 amino acids. A cDNA with identical sequence was subsequently obtained from the mouse pre-B cell line 70Z/3 by reverse transcriptase polymerase chain reaction based on sequence of the mC3aR gene. Northern blot analysis suggested expression of the mC3aR in lung and heart, and to a lesser extent, in brain, liver, muscle, kidney, and testis. The deduced amino acid sequence of the mouse C3aR is 65% identical to that of the human C3aR. Like the human receptor, mouse C3aR contains a predicted large extracellular loop of approximately 165 amino acids (residues 161-325) between the fourth and fifth transmembrane domains. This loop, however, is the least conserved structure (45% identical sequence) of all the extracellular and intracellular domains between the mouse and human C3aRs. The mouse gene product bound 125I-labeled human C3a with a Kd of 2.54 nM when expressed in the stably transfected rat basophilic leukemic cell line RBL-2H3. Bound C3a could be effectively displaced by excess quantities of unlabeled C3a, but not by C4a or C5a. C3a induced dose-dependent calcium mobilization in the transfected cells, which could be blocked by pertussis toxin treatment. These results confirm that the cloned gene encodes a functional C3aR capable of coupling to a pertussis toxin-sensitive G protein. The sequence divergence of the large extracellular loop does not appear to affect C3a binding and transmembrane signaling.

Peroxisome proliferator activated receptor-alpha expression in human liver

The peroxisome proliferator activated receptor alpha (PPAR) is a member of the steroid/hormone receptor superfamily that mediates the peroxisome proliferator-dependent transcriptional activation of genes encoding several peroxisomal and microsomal enzymes as well as peroxisome proliferation. Human liver is refractory to the pathological effects of peroxisome proliferators that are seen in mice. With the use of RNase protection assays, the ratio of hepatic PPAR alpha mRNA to beta-actin mRNA was found to be 1 order of magnitude lower in humans than that observed in mice. In addition, the isolation of human cDNA for PPAR alpha that does not encode a functional PPAR because it lacks exon 6 as a result of alternate RNA splicing suggested that this process might also diminish the expression of PPAR alpha. RNase protection analysis of total RNA revealed the presence of splice variants lacking exon 6 at significant levels in all 10 human liver samples examined. Supershift analysis using the CYP4A6-Z peroxisome proliferator response element and antisera specific for PPAR alpha revealed easily detectable amounts of PPAR alpha DNA binding activity in mouse liver lysates, whereas human liver lysates contained > 10-fold lower amounts of PPAR alpha DNA binding activity. In contrast to mouse lysates, the amount of PPAR alpha binding in human lysates was generally less than that of other unidentified proteins. These results suggest that although humans retain the coding potential for a functional receptor, the low levels of PPAR alpha expression in liver may be insufficient to compete effectively with other proteins that bind to peroxisome proliferator response elements.

Phosphorylation of the N-formyl peptide receptor is required for receptor internalization but not chemotaxis

The human N-formyl peptide receptor (FPR) is a member of the family of leukocyte, G protein-coupled, chemoattractant receptors. To determine the role(s) of receptor phosphorylation in FPR processing and formylmethionylleucylphenylalanine (fMLF)-mediated chemotaxis, we utilized U937 cells expressing the recombinant wild type receptor and a mutant form of the FPR. This mutant, which lacks all of the serine and threonine residues in the C terminus of the receptor, DeltaST, has recently been shown to produce a receptor capable of fMLF binding and G protein activation but was demonstrated not to undergo fMLF-dependent phosphorylation or desensitization of the calcium mobilization response upon repeated exposure to agonist (Prossnitz, E. R. (1997) J. Biol. Chem. 272, 15213-15219). In this report, we examined the role of receptor phosphorylation in FPR internalization and leukocyte chemotaxis. Whereas the wild type receptor was rapidly internalized upon stimulation, the phosphorylation-deficient mutant was not, remaining entirely on the cell surface. In addition, contrary to the hypothesis that receptor processing and recycling are required for chemotaxis, we found no defect in the ability of the mutant FPR to migrate up a concentration gradient of fMLF. These results indicate that phosphorylation of the FPR is a necessary step in receptor internalization but that receptor phosphorylation, desensitization, and internalization are not required for chemotaxis.

Salvage neck dissection for cervical recurrence of nasopharyngeal carcinoma

OBJECTIVE

To evaluate the effectiveness of salvage neck dissection as part of a multidisciplinary treatment approach in persistent or recurrent metastatic nasopharyngeal carcinoma, after failure of initial radiotherapy at the regional site.

DESIGN

A retrospective study of 31 patients treated during a 14-year period from March 1981 through May 1995, with a maximum follow-up of 152 months. Factors evaluated include patients' sex, age, and initial stage of tumor, mobility and number of nodal recurrences, surgical and pathological findings, and postoperative irradiation.

SETTING

Academic tertiary referral center.

PATIENTS

Twenty-six men and 5 women were studied; one patient had neck dissection to both sides of the neck on separate occasions, for a total of 32 operations. All patients had pathologically proved nasopharyngeal carcinoma and had been previously treated at the primary site and both sides of the neck with definitive radiotherapy.

INTERVENTION

Patients underwent a radical, modified radical, or level I-sparing radical neck dissection.

MAIN OUTCOME MEASURE

Surgical morbidity, time to recurrence at the regional site, and survival time.

RESULTS

Clinically, there was a disease predilection of 81% at levels II and V. Surgical morbidity was minimal. Regional control was achieved in 20 (65%) of the patients, and the overall 5-year survival was 67%. Tumor involvement of the posterior triangle musculature and spinal accessory nerve was associated with failure to control neck disease. Extracapsular nodal extension correlated with a poor survival outcome.

CONCLUSION

Control of regional disease by salvage neck dissection when radiotherapy has failed is both safe and effective in properly selected patients.

Role of the peroxisome proliferator-activated receptor in cytochrome P450 4A gene regulation

Cytochrome P450s of the 4A subfamily generally catalyze the omega-hydroxylation of fatty acids. The induction of P450 4A enzymes by peroxisome proliferators or fatty acids is mediated by peroxisome proliferator-activated receptors (PPARs), which are members of the nuclear receptor family that regulates the expression of genes that control fatty acid synthesis, storage, and catabolism. PPARs bind as heterodimers with another member of the nuclear receptor family, the retinoid X receptor (RXR), to peroxisome proliferator response elements (PPREs) in the P450 4A1 and 4A6 genes. PPREs comprise two overlapping motifs for nuclear receptor binding. One motif consists of an imperfect, direct repeat of two copies of the nuclear receptor core binding site, AGGTCA, separated by a single nucleotide (a DR1 motif) that is recognized by other dimeric nuclear receptor complexes such as HNF-4 or ARP-1. A consensus sequence flanking the DR1 motif together with the 5' core binding site of the DR1 motif constitutes a second, overlapping motif resembling recognition elements for monomeric nuclear receptors, such as Rev-ErbA and the melatonin receptors. PPARs bind to the latter motif. The tripartite nature of PPREs together with imperfections in the core sites of DR1 motif confers specificity for PPAR alpha/RXR alpha binding to PPREs relative to other nuclear receptors.

Human fatty-acid synthase gene. Evidence for the presence of two promoters and their functional interaction

We have isolated and sequenced a genomic clone coding for the first three exons and the 5'-flanking region of the human fatty-acid synthase gene. The translation initiation site, ATG, is located in exon II. Primer extension and S1 nuclease analyses showed the presence of three transcription initiation (Ti) sites: Ti I, Ti II, and Ti III. The Ti I site is mapped to the beginning of the untranslated exon I and preceded by a promoter with recognizable TATA and CAAT boxes. The Ti II and Ti III sites are located in intron I, at 60 and 49 nucleotides upstream of the translation initiation site ATG in exon II, respectively. These two Ti sites are preceded by four putative Sp1 boxes, but lack TATA and CAAT boxes. Analysis of luciferase reporter gene expression in transient transfection assays confirmed the existence of two promoters. A 200-base pair 5'-flanking region, which has strong promoter activity comparable with that of the CMV promoter, is considered human fatty-acid synthase promoter I. In a wild-type human fatty-acid synthase-luciferase construct, in which promoter I and intron I are present in their natural configuration, the reporter gene activity is only 1% of that of promoter I. Deletion analysis showed the existence of promoter II, which is located in intron I immediately upstream of the Ti II site. The strength of promoter II is approximately th of that of promoter I in transient transfection assays. Further analysis of reporter gene constructs showed that promoter II inhibited the reporter gene activity of the wild-type construct that contained promoter I and intron I and that the spatial separation of the two promoters is important for this inhibition. A model is proposed based on the possibility that the assembly of transcription complexes on promoter II creates a "roadblock" and reduces the overall expression of the fatty-acid synthase gene by interfering with the progression of transcription from promoter I.

Regulation of the human bilirubin UDP-glucuronosyltransferase gene

The human UGT1 gene is a single copy gene consisting of four common exons and more than 13 variable exons which span more than 200 kb of the human genome. A single variable exon is spliced to the four common exons to form the mRNA for synthesis of a single UDP-glucuronosyltransferase (UGT) isoenzyme. Treatment of humans or hepatoma cell lines with drugs such as phenobarbital causes the induction of hepatic bilirubin UGT by increased transcription from the UGT1 gene. The upstream region of UGT1*1 (bilirubin UGT) was sequenced and found to contain consensus sequences for several transcriptional regulatory elements including a 'BARBIE box'. An unusual 'TATA' promoter sequence A(TA)6TAA was also observed. The 5' region flanking the UGT1*1 exon when cloned into reporter constructs and transfected into four cells lines was capable of promoting reporter gene expression, but not when transfected into monkey kidney cell fibroblasts (COS-7 cells) indicating a cell specific expression. Sequential deletion of the 5' flanking region in the plasmid constructs did not cause any significant reduction in reporter expression. Treatment of cells transfected with these plasmid constructs with drugs did not cause a significant increase in reporter expression except with retinoic acid plus WY 14643. Introduction of an additional two base pairs (TA) into the 'TATA' box of the 5' gene sequence (as observed in Gilbert's patients) did not significantly change reporter expression levels. The regulation of the biliruibin UGT gene by drugs is not yet understood and it will be important to identify additional genetic elements possibly further than -2kb upstream of the UGT1*1 coding region, which regulate the expression of this gene.

A single amino acid change in the mouse peroxisome proliferator-activated receptor alpha alters transcriptional responses to peroxisome proliferators

The mouse peroxisome proliferator-activated receptor alpha (mP-PAR alpha) can activate transcription from the CYP4A6 promoter in transient cotransfection experiments in the absence (intrinsic transactivation) or presence of added peroxisome proliferator. However, mPPAR alpha-G, in which glycine is substituted for Glu282, exhibits very low intrinsic transactivation and responds fully to added peroxisome proliferators. The two receptors, when expressed in COS-1 cells, are nuclear in localization, are expressed at similar levels, have similar stability, and bind DNA in vitro with similar efficiency. The phenotypic difference in intrinsic transactivation is not altered by overexpression of the human retinoid X receptor alpha. The mPPAR alpha-G mutant receptor displays a higher EC50 for pirinixic acid and for 5,8,11,14-eicosatetraynoic acid than the wild-type PPAR alpha. This difference in the apparent EC50 value is independent of the cell lines used and indicates that the Glu282 to glycine substitution alters the response of mPPAR alpha to peroxisome proliferators. The EC50 values obtained for each receptor with the CYP4A6 reporter construct are lower than those for a reporter derived from the acyl-CoA oxidase gene. In general, an inverse relation is evident between the apparent EC50 values and the extent of intrinsic transactivation observed. The difference in intrinsic transactivation may reflect the presence of an endogenous activator at a concentration that is not sufficient to activate the mPPAR alpha-G but that is sufficient to effect the intrinsic transactivation seen for the wild-type mPPAR alpha.

Novel sequence determinants in peroxisome proliferator signaling

The gene encoding cytochrome P-450 4A6 (CYP4A6) is transcriptionally activated by peroxisome proliferators. This response is dependent on a strong enhancer element (Z) and weaker elements (X and -27). The peroxisome proliferator response is mediated by the binding of heterodimers containing the peroxisome proliferator-activated receptor alpha (PPAR alpha) and the retinoid X receptor alpha (RXR alpha) to these elements. These peroxisome proliferator response elements (PPREs) contain imperfect direct repeats of the nuclear receptor consensus recognition sequence with a spacing of one nucleotide (DR1) (AGGTCA N AGGTCA). This DR1 motif is seen in the binding sites for other nuclear receptor complexes, such as ARP-1, HNF-4, and RXR alpha homodimers. Mutational analysis of the Z element reveals that the DR1 motif is required for the transcriptional activation of the CYP4A6 gene by peroxisome proliferators; however, deletion of sequences immediately upstream of this motif also abolishes this response. Oligonucleotides corresponding to truncated and mutated Z elements were assayed by gel retardation for binding to RXR alpha, PPAR alpha, and ARP-1. Deletions or mutations within six nucleotides 5' of the DR1 motif dramatically diminish PPAR alpha.RXR alpha binding without reducing the binding of either RXR alpha or ARP-1 homodimers, whereas mutation or deletion of the core DR1 sequences abolishes the binding of PPAR alpha.RXR alpha heterodimers and of RXR alpha or ARP-1 homodimers. Thus, the DR1 motif in the Z element is not sufficient to constitute a PPRE. Moreover, the binding of PPAR alpha.RXR alpha to the Z element requires sequences immediately 5' of the DR1. These sequences are conserved in natural PPREs and promote binding of PPAR alpha.RXR alpha heterodimers in preference to potential competitors such as ARP-1 and RXR alpha.

Interaction of the peroxisome proliferator-activated receptor alpha with the retinoid X receptor alpha unmasks a cryptic peroxisome proliferator response element that overlaps an ARP-1-binding site in the CYP4A6 promoter

P450 4A6 is highly induced by peroxisome proliferators in vivo. Gene transfer experiments indicate that this induction can be mediated by the mouse peroxisome proliferator-activated receptor alpha (PPAR alpha) and that it is dependent on upstream enhancer elements in the CYP4A6 gene. However, as has been seen for other peroxisome proliferator response elements (PPREs), PPAR alpha does not bind directly to a previously characterized PPRE of the CYP4A6 gene in the absence of additional proteins such as the retinoid X receptor alpha (RXR alpha). When PPAR alpha and RXR alpha are coexpressed, the overall transcription of the CYP4A6 reporter is increased, and a synergistic response to both retinoids and peroxisome proliferators is evident that is dependent on the presence of both receptors. In addition, a cryptic response element is unmasked in constructs lacking the upstream enhancers. DNase I protection assays indicate that when present together, but not singly, PPAR alpha and RXR alpha bind to a site located within 29 base pairs upstream of the CYP4A6 transcription start site. This region contains a sequence similar to that found in the apolipoprotein CIII gene that has been shown to bind RXR alpha and the orphan nuclear receptor, ARP-1. The corresponding sequence in the CYP4A6 gene also binds ARP-1. A similar sequence found in the promoter region of the rat CYP4A1 gene does not, however, bind either PPAR alpha/RXR alpha or ARP-1. Transfection of increasing amounts of the ARP-1 expression vector blocks the PPAR alpha/RXR alpha-mediated induction of transcription from the CYP4A6 promoter. Mutations that prevent the binding of either PPAR alpha/RXR alpha or ARP-1 to a double-stranded oligonucleotide corresponding to the proximal enhancer eliminate the peroxisome proliferator-induced transcriptional response observed for the promoter construct in the presence of PPAR alpha/RXR alpha, but these mutations do not eliminate the response seen when the upstream enhancers are present. These results indicate that the PPREs of the CYP4A6 gene are recognized by multiple members of the nuclear receptor family that are likely to contribute to the regulation of CYP4A6 expression in both an agonistic (RXR alpha) and an antagonistic (ARP-1) manner.

Photoreceptor damage following exposure to excess riboflavin

Flavins generate oxidants during metabolism and when exposed to light. Here we report that the photoreceptor layer of retinas from black-eyed rats is reduced in size by a dietary regime containing excess riboflavin. The effect of excess riboflavin was dose-dependent and was manifested by a decrease in photoreceptor length. This decrease was due in part to a reduction in the thickness of the outer nuclear layer, a structure formed from stacked photoreceptor nuclei. These changes were accompanied by an increase in photoreceptor outer segment autofluorescence following illumination at 328 nm, a wavelength that corresponds to the excitation maxima of oxidized lipopigments of the retinal pigment epithelium.