Luminescence Properties of Epitaxial Cu2O Thin Films Electrodeposited on Metallic Substrates and Cu2O Single Crystals

The luminescent properties of epitaxial Cu₂O thin films were studied in 10-300 K temperature range and compared with the luminescent properties of Cu₂O single crystals. Cu₂O thin films were deposited epitaxially via the electrodeposition method on either Cu or Ag substrates at different processing parameters, which determined the epitaxial orientation relationships. Cu₂O (100) and (111) single crystal samples were cut from a crystal rod grown using the floating zone method. Luminescence spectra of thin films contain the same emission bands as single crystals around 720, 810 and 910 nm, characterizing VO2+, VO+ and VCu defects, correspondingly. Additional emission bands, whose origin is under discussion, are observed around 650-680 nm, while the exciton features are negligibly small. The relative mutual contribution of the emission bands varies depending on the thin film sample. The existence of the domains of crystallites with different orientations determines the polarization of luminescence. The PL of both Cu₂O thin films and single crystals is characterized by negative thermal quenching in the low-temperature region; the reason of this phenomenon is discussed.

[Exploratory study on detection of drug resistance of Mycobacterium tuberculosis in sputum specimens by next-generation sequencing]

Objective: To compare the diagnostic performance of next-generation sequencing (NGS) detection methods in sputum samples and Mycobacterium tuberculosis strains, in order to explore the feasibility of the NGS method to detect drug resistance in sputum specimens. Methods: In this retrospective study, the sputum specimens and corresponding clinical isolates of 50 pulmonary tuberculosis patients admitted to Beijing Chest Hospital from January 2017 to December 2017 were collected. The gene mutations of katG, inhA, rpoB, embA, embB, rpsL, rrs, gyrA, gyrB and tlyA in sputum specimens and corresponding clinical isolates were detected by NGS method. The phenotypic drug susceptibility test (DST) of the strains was carried out by the proportion method. Using DST results as a reference, the sensitivity, specificity, positive predictive value and negative predictive value of the NGS method for clinical strains and sputum specimens, as well as the consistency statistic (Kappa) with phenotype DST were calculated respectively. The Chi-square test was used to compare the accuracy of the NGS testing in sputum samples and strain samples. Results: The results showed that rpoB(63.83%, 30/47) and rrs(57.45%, 27/47) were the most common mutated genes, followed by katG(46.81%, 22/47), rpsL(29.79%, 14/47), gyrA(27.66%, 13/47), embB(21.28%, 10/47), tlyA(12.77%, 6/47), gyrB(8.51%, 4/47), and inhA promoter(19.15%, 9/47), embA promoter region (12.77%, 6/47) mutation. when the NGS method was compared with the resistance phenotype of isoniazid, rifampicin, ethambutol, second-line injectable drugs (streptomycin, capreomycin, kanamycin, amikacin), levofloxacin, the sensitivity were 85.71%, 91.67%, 77.78%, 81.82%, 100.00%, 87.50%, 100.00%, 69.23%, and the specificity were 100.00%, 94.12, 87.50%, 89.47%, 97.06%, 96.97%, 94.29%, 89.29% in sputum samples, while in strain samples, the sensitivity were 92.86%, 100.00%, 81.82%, 86.96%, 88.89%, 80.00%, 100.00%, 85.71%. The specificity were 100.00%, 92.86%, 87.10%, 94.74%, 100.00%, 100.00%, 97.14%, 92.86%. Compared with the phenotypic drug susceptibility results, the NGS method has better detection performance for isoniazid, rifampicin, capreomycin, kanamycin, and amikacin in sputum specimens (Kappa≥0.75); while among the strains, the NGS method had a good detection performance for isoniazid, rifampicin, streptomycin, capreomycin, kanamycin, amikacin and levofloxacin (Kappa≥0.75). With the accuracy of the NGS method for detecting strains as a reference, there was no statistically significant difference in the accuracy of all drug resistance detected between strains and sputum specimens. Conclusions: This study showed that the NGS technology was effective in predicting the resistance of isoniazid, rifampicin, and second-line injectable drugs (capreomycin, kanamycin and amikacin) by detecting sputum samples and strain genotypes, suggesting the feasibility and potential of direct detection of sputum samples by the NGS method as an early detection method for drug resistance.

Navigational Transmaxillary Endoscopic Approach for Inferomedial Tumors

Orbital tumors encompass a heterogeneous range of histopathology and usually variable in location. Traditionally, transconjunctival medial orbitotomy is used to access the medial orbital wall. However, it creates potential risk of soft tissue sequelae such as scarring, lid contracture, or entropion/ectropion. For the lesions close to the orbital apex, increased risk of optical nerve injury should be cautious during orbitotomy procedure. Transnasal endoscopic approach to the orbital walls has been applied since 1999. Although it provides good surgical visualization and prevents the soft tissue and neural complications, the narrow nasal corridor increases the surgical complexity. Extensive sphenoethmoidectomy is usually required to gaining access. Furthermore, the resultant medical orbital defect is difficult to repair. The maxillary sinus is the largest paranasal sinuses which is located beneath the orbital floor. It provides an ample working space for instrumentation. Meanwhile, repair of the orbital floor defect is feasible and with high degree of accuracy under navigation control. In this report, we propose a novel computer-assisted endoscopic protocol to excise the medial orbital tumors with immediate repair of the wall defect.

True vertical changes in patients with skeletal class III malocclusion after nonsurgical orthodontic treatment—a retrospective study comparing different vertical facial patterns

Background/purpose

Rotating mandible backward downward is one of the treatment options in non-surgical skeletal class III malocclusion. The purpose of this study was to compare the true vertical changes after camouflage orthodontic treatment of adult patients with skeletal class III malocclusion categorized by vertical facial type.

Materials and methods

This retrospective study included 27 adult patients (age >18 years) with skeletal class III malocclusion (ANB<1°) who underwent nonsurgical orthodontic treatment at Taipei Veterans General Hospital. The patients were divided into the low-angle (SN-MP<28°), high-angle (SN-MP>36°), and normal-angle (28°≤ SN-MP ≤ 36°) groups according to the original vertical facial pattern. Pretreatment (T1) and post-treatment (T2) lateral cephalograms were superimposed and treatment changes were evaluated.

Results

In all cases, proper overjet and occlusion were achieved after treatment, and the lower anterior facial height increased with the backward rotation of the mandibular plane. Increase in vertical dimension was the most obvious in the high-angle group, while it was the least obvious in the low-angle group. Extrusion of both the maxillary and mandibular incisors was observed in the high-angle group; however, intrusion of the maxillary and mandibular incisors and decreased overbite were observed in the low-angle group.

Conclusion

Camouflage orthodontic treatment of skeletal class III malocclusion improves the facial profile by increasing the vertical dimension and clockwise rotation of the mandible. According to our results, patients with a high mandibular plane angle showed better response to vertical dimension increment treatment mechanics than those with low and normal mandibular plane angles.

A digital photograph study evaluating facial taperness and square face perception of Taiwanese females

BACKGROUND

This study assessed the perception of facial taperness in Taiwanese females among people with dental knowledge and laypersons. Additionally, this study also specified the criteria by which "square face" was defined regarding Taiwanese females' facial taperness.

METHODS

A series of digitally modified photos with different levels of facial taperness (Gonion to Gonion/Zygoma point to Zygoma point-Go-Go/Zy-Zy ratio ranges from 65% to 90%) were randomly arranged and presented to the raters. Visual analog scale (VAS) lines were used for scoring the photos on a scale of 0-100. The true or false question about "defining square face" was incorporated in the same questionnaire. The reliability of the true/false square face question and the esthetic evaluation by VAS were assayed. The receiver operating characteristic curve was used to define the cutoff point on "square face." The effects on the raters' genders, orthodontic treatment experience, and their professional background on the perception of a square face were assayed.

RESULTS

The overall reliability of the raters was within the acceptable range. The VAS score evaluation revealed that the average expectation for best facial taperness was 75%, whereas the facial taperness of over 83% was considered as the square face. The facial taperness reaching to 90% was regarded as the most unattractive. Gender, therapy, and professional experience have no impact on the standard of square facial form evaluation.

CONCLUSION

A face with a taperness greater than 83% was evaluated as a square face, and a face with a taperness around 75% was considered as the most attractive.

Evaluation of factors associated with the risk stratification of survivorship for stage IV squamous cell carcinoma of the oral cavity: A 10-year retrospective study

BACKGROUND

Oral squamous cell carcinoma (OSCC) leads to thousands of deaths every year in Taiwan. Nearly 40% of OSCC patients are diagnosed with stage IV disease, which has a poor prognosis. Multimodality treatments including surgery and adjuvant therapy have been utilized, but their treatment outcomes are generally poor. In this study, we sought to identify possible clinical impact factors that may contribute to the survival of stage IV OSCC.

METHODS

Data for patients with malignant neoplasms of the oral cavity registered in the Cancer Registry Database of Taipei Veterans General Hospital between 2002 and 2011 were retrieved. The study patients consisted of OSCC patients with clinical stage IV disease who had undergone a surgery and adjuvant therapy. The primary endpoints were the 5-year disease-free survival (DFS) and overall survival (OS) rates. The clinicopathological characteristics of the patients were also stratified and compared.

RESULTS

A total of 191 OSCC patients were included for retrospective analysis. The different subgroups of stage IV disease presented different treatment outcomes. The 5-year OS versus DFS rates of each subgroup were as follows: T4N0: 70.9% versus 52.6%; T1-3N23: 66.1% versus 49.8%; T4N1: 49.6% versus 31.6%; and T4N23: 40.9% versus 31.0% (p < 0.01). Patients with diabetes, moderate or poor cell differentiation, perineural invasion, and extracapsular spread presented lower 5-year OS rates (hazard ratio [HR] = 1.87, 1.65, 2.42, and 2.14, respectively), and patients with perineural invasion, positive cut margin, and extracapsular spread presented lower 5-year DFS rates (HR = 1.57, 1.62, and 1.71, respectively).

CONCLUSION

In this study, we elucidated the different survival rates of different subgroups of stage IV OSCC following the same treatment scheme. The results of the study provide clinical physicians with references by which to evaluate prognosis and determine post-operative disease monitoring timetables based upon different characteristics.

[Analyses of diagnosis and treatment of foreign body aspiration in children with tracheobronchial variations]

Objective: To investigate the key issues in the diagnosis and treatment of foreign body aspiration in children with tracheobronchial variations. Methods: A retrospective study was performed for 11 pediatric patients who were treated in Department of Otorhinolaryngology and Head and Neck Surgery, Henan Province People's Hospital after a diagnosis of foreign body aspiration with tracheobronchial variations between January 2015 and December 2017. There were 7 males and 4 females among the 11 cases of foreign body aspiration with tracheobronchial variations, ranging between 9 months and 11 years of age. Results: Among 11 cases, the types of variationswere tracheal bronchus in 9 cases, bridging bronchus in 1 case and simple tracheal stenosis in 1 case. All of the pediatric patients were under general anesthesia, and the foreign bodies were removed by bronchoscopy successfully with no significant complications. Conclusions: The possibility of tracheobronchial variations should be considered in children with recurrent wheezing and poor efficacy of regular treatment before foreign body aspiration. Removal of foreign body via rigid bronchoscope under general anesthesia is a safe and effective treatment. These children are needed to combine the situation oftracheobronchial variations and the location of foreign bodies to guide the operation, and strengthened the perioperative treatment.

Deep intronic variant c.5999-277G>A of F8 gene may be a hot spot mutation for mild hemophilia A patients without mutation in exonic DNA

BACKGROUND

In 10%-18% of mild-type hemophilia A (HA) patients, mutations cannot be found by routine DNA analysis.

OBJECTIVE

We aimed to identify the genetic defects by mRNA analysis of F8 gene in mild HA patients without mutation in exonic DNA.

PATIENTS AND METHODS

From 2006 to 2016, we identified F8 exon mutations in 39 of 49 mild HA patients using routine genetic testing. We then evaluated the 10 remaining patients from six unrelated families without exonic DNA mutation by performing cDNA sequence analysis.

RESULTS

Nine of the 10 (90%) patients were confirmed to have F8 gene mutation. Eight patients from four unrelated families were notably found to have presence of an aberrant 675-bp fragment. Sequencing of this fragment showed that there were two separate new alternative splicing exons of 35 bp and 55 bp within intron 18, which formed a 90-bp insertion between exon 18 and exon 19 (E18ins90bpE19) in the mRNA. Based on direct sequencing, this alternative splicing transcript appears to have resulted from deep intronic variant c.5999-277G>A of intron 18.

CONCLUSIONS

Our study suggests that deep intronic variant of c.5999-277G>A may be a hot spot mutation for mild hemophilia patients without mutation in exonic DNA.

Comparing the reliability and accuracy of clinical measurements using plaster model and the digital model system based on crowding severity

BACKGROUND

This study aims to clarify whether 3Shape™ digital model system could be applied in orthodontic diagnostic analysis with certainty, especially under different crowding condition. Reliability, accuracy and efficiency of 3Shape™ digital model system were assessed by comparing them with traditional plaster cast.

METHODS

29 plaster casts with permanent dentition were transformed into digital models by 3Shape™ D800 scanner. All 29 models were categorized into mild-crowding (arch length discrepancy <3 mm), moderate-crowding (arch length discrepancy >3 mm and <8 mm), and severe-crowding group (arch length discrepancy >8 mm). Fourteen linear measurements were made manually using a digital caliper on plaster casts and virtually using the 3Shape™ Ortho Analyzer software by two examiners. Intra-class Correlation Coefficient (ICC) was used to evaluate intra-examiner reliability, inter-examiner reliability and reliability between two model systems. Paired t test was used to evaluate accuracy between two model systems. Kruskal-Wallis test followed by Mann-Whitney U test was used to evaluate the measurement differences between 3 groups in two model systems.

RESULTS

Both intra-examiner and inter-examiner reliability were generally excellent for all measurements made on 3Shape™ digital model and plaster cast (ICC: 0.752-0.993). Reliability between different model systems was also excellent (ICC: 0.897-0.998). Half of the accuracy test showed statistically significant differences (p < 0.05) when digital models were compared with plaster casts. Furthermore, while assessing measurement differences between 3 groups in two model systems, the mandibular required space showed significant difference (p = 0.012) between mild crowding group (0.27 + 0.01 mm) and severe crowding group (0.20 + 0.09 mm). However, the differences were less than 0.5 mm and would not affect clinical decision.

CONCLUSION

Using 3Shape™ digital model system instead of plaster casts for orthodontic diagnostic measurements is clinically acceptable.

Peripheral nerves are pathologically small in cerebellar ataxia neuropathy vestibular areflexia syndrome: a controlled ultrasound study

BACKGROUND AND PURPOSE

Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls.

METHODS

We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 patients with CANVAS with 14 healthy controls and 14 age- and gender-matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of patients with CANVAS and neuropathy with the reference values of our laboratory control population.

RESULTS

The nerve cross-sectional area of patients with CANVAS was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (P < 0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger in neuropathy controls than healthy controls (P < 0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one patient with CANVAS.

DISCUSSION

Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy.

A new dispersion interferometer on HL-2A

In order to avoid a fringe jump caused by high plasma density and pellet injection [Y. Zhou et al., Rev. Sci. Instrum. 87, 11E107 (2016)], a new CO₂ dispersion interferometer is designed and commissioned on HL-2A for average line-density measurement and density feedback control. The second harmonic technology in this system eliminates the phase shift caused by mechanical vibration. Signals are processed by a digital phase comparator and can be monitored in real time. A series of experiments are conducted to study the characteristics of the system such as a second harmonic coefficient and long-term stability. The resolution of density measurement is less than 8 × 10¹⁷/m³, and the experiment result on HL-2A demonstrates the interferometer's capability to track plasma density evolution with rapid change. The system also shows good stability against mechanical vibrations.

Trends in hip fracture rates in Taiwan: a nationwide study from 1996 to 2010

There was an initial increase and a later decrease in hip fracture rates in Taiwan between 1996 and 2010 (457.9 to 390.0 fractures per 100,000 people per year). Mortality rates decreased but re-emerged later (2.26 to 1.91 deaths per 100 hip fracture admissions). The turning point for change in trends was 2003.

INTRODUCTION

Fractures of the proximal femur remain a major cause of mortality and morbidity. We aimed to examine recent trends in hip fracture rates, in-hospital mortality rates, and length of hospital stay (LOS) due to hip fractures in people aged 55 and over in Taiwan.

METHODS

This is a time-trend study. We used data from the National Health Insurance Research Database between 1996 and 2010 in Taiwan. Insurants aged 55 and over were included. The outcome measures were age-adjusted hip fracture rates, age-adjusted in-hospital mortality rates, and LOS due to hip fractures. We classified hip fractures into femoral neck, trochanteric, and subtrochanteric fractures.

RESULTS

We identified 250,919 hospitalizations for hip fractures. The total number of hip fractures increased steadily from 12,479 to 19,841 cases. There was a trend towards initial increase and then later decrease in hip fracture rates (from 457.9 to 390.0 fractures per 100,000 people per year). LOS decreased by 46.5 % (17.53 to 9.38 days). By contrast, mortality rates for hip fractures decreased initially, but re-emerged later with a total decrement of 15.5 % (2.26 to 1.91 deaths per 100 hip fracture admissions). Women outnumbered men in all types of hip fractures, but men had higher in hospital mortality rates. LOS was similar between genders and among age groups. The turning point for change in trends was year 2003.

CONCLUSIONS

While LOS shortened gradually since 1996, the absolute number of hip fractures in Taiwan continues to rise. There is still room for improvement in reducing mortality due to hip fractures.

Comparison of job burnout and life satisfaction between native and foreign female direct care workers in disability institutions

BACKGROUND

There is little information about the burnout and wellbeing of institutional caregivers working for people with intellectual and developmental disabilities; information is particularly limited in the understanding of experiences of direct care workers.

OBJECTIVE

The aims of the study were to provide a profile of self-perceived burnout and wellbeing of direct-care caregivers working in disability institutions, and to compare the difference between native- and foreign caregivers.

METHODS

A cross-sectional survey was conducted. We recruited 46 female living assistants of people with intellectual and developmental disabilities in two disability institutions in Taiwan. There were 23 subjects who were local residents and 23 subjects who were foreign providers of labor. A self-administered questionnaire which included scale of the Copenhagen Burnout Inventory (CBI), the Subjective Happiness Scale (SHS), and the Satisfaction with Life Scale (SWLS) were employed in the survey.

RESULTS

Findings revealed the local caregivers were slightly higher than foreign caregivers in personal burnout score (PBS) and work-related burnout score (WBS), although there were no significant differences. Those caregivers from foreign countries seem to be slightly happier and have higher life satisfaction than native caregivers.

CONCLUSIONS

In order to decrease the burnout and improve wellbeing of caregivers of people with intellectual and developmental disabilities, service providers should understand the experiences which caregivers encounter in their workplaces. Caregivers can benefit if they receive appropriate support to improve positive health while working for their service clients.

HOTAIR inhibited intracellular Ca2+ via regulation of Cav1.2 channel in human cardiomyocytes

HOTAIR, a long non&mdash;coding RNA (lncRNA), is reported to regulate chromatin organization and promote tumor progression. However, little is known about the roles of this gene in the modulation of calcium homeostasis in human cardiomyocytes. In the present study, we demonstrated that up&mdash;regulation of HOTAIR could suppress the expression of CaV1.2 in human cardiomyocytes. However, HOTAIR knockdown promoted CaV1.2 expression in human cardiomyocytes. In addition, we found that HOTAIR overexpression significantly reduced the intracellular Ca2+ contents; while knockdown of HOTAIR enhanced the Ca2+ contents in the cardiomyocytes. Moreover, enforced expression of CaV1.2 increased the calcium level in cardiomyocytes overexpressing HOTAIR. down&mdash;regulation of HOTAIR and up&mdash;regulation of CaV1.2 further enhanced the Ca2+ contents in the cardiomyocytes Taken together, these results for the first time demonstrate that HOTAIR inhibited the intracellular Ca2+ via regulation of CaV1.2 in human cardiomyocytes.

Hospital-based integrated diabetes care management: an overview

To provide continuous, accessible, and quality care, a diabetes share-care program has been in place in Taiwan for several years. Lukang Christian Hospital, a member of the diabetes share-care network, endeavors to provide "patient-centered" care aimed at increasing care quality and reducing diabetic complications. Information technology has been employed by the hospital for monitoring care quality and analyzing cost-effectiveness. Structured health-care programs have also been developed to ensure the completeness of diabetes care and to encourage self-management of individuals at high risk for diabetes. The implementation of these strategies has led to progressive improvement in quality measures and spawned novel and creative ways to deliver care services.

An exploratory study of health behaviors and the risks for triple H (hypertension, hyperlipidemia, and hyperglycemia) in young adults with disabilities between 20 and 39 years of age

Metabolic syndrome is highly prevalent and has important implications for the health care sector. However, information on the implications of metabolic syndrome for people with disabilities is limited. The purpose of this study was to explore the relationship between health behaviors and the risk for triple H (hypertension, hyperlipidemia, and hyperglycemia) in young adults with disabilities. The present study analyzed the annual health examination charts of 705 young adults with disabilities between ages 20 and 39 in Taiwan. Results found that the prevalence of hyperglycemia, hyperlipidemia, and hypertension in adults with disabilities was 5%, 15% and 17.7%, respectively. These prevalence figures were higher than those for the general population of the same age group in Taiwan. Multivariate logistic regression analyses revealed that almost none of the health behaviors were significantly correlated with the occurrence of triple H disorders among young adults with disabilities. Only one factor, BMI, independently predicted the occurrence of triple H disorders. We suggest that future studies should scrutinize the effects of health behaviors on triple-H disorders in people with disabilities to initiate personalize health promotion programs for this group.

Angiotensin II type 1 receptor antagonist attenuates lung fibrosis in hyperoxia-exposed newborn rats

Bronchopulmonary dysplasia (BPD) remains a major cause of morbidity and mortality during the first year of life, and many infants have significant respiratory problems throughout childhood. Currently no effective therapy is clinically available to prevent the long-term pulmonary sequelae of BPD. Previous research has demonstrated that the renin-angiotensin system is up-regulated in human lung fibroblasts. Angiotensin II type 1 receptor (AT₁R) antagonists and AT₁R short interfering RNA diminished hyperoxia-increased collagen expression, whereas AT₂R antagonists did not have any effects on these hyperoxia-induced changes. The in vivo therapeutic effects of AT₁R antagonists on hyperoxia-induced lung fibrosis remain unknown. The present study assessed the effects of an AT₁R antagonist (losartan) on preventing hyperoxia-induced lung fibrosis in newborn rats. Rat pups were exposed to 7 days of > 95% O₂ and an additional 2 weeks of 60% O₂. AT₁R antagonist-treated pups were injected intraperitoneally with losartan at a dose of 10 mg/kg/day from postnatal days 1 to 7 and a dose of 5 mg/kg/day from postnatal days 8 to 21. Control group pups were injected with an equal volume of normal saline. AT₁R antagonist treatment attenuated the hyperoxia-induced lung fibrosis on postnatal days 7 and 21 and also decreased the hyperoxia-induced expression of extracellular signal-regulated protein kinase and α-smooth muscle actin. AT₁R antagonist treatment did not affect body weight or lung weight of the rats. These data suggest that AT₁R antagonist may offer a novel therapeutic strategy for preventing hyperoxia-induced lung fibrosis.

The renin-angiotensin system mediates hyperoxia-induced collagen production in human lung fibroblasts

A high concentration of oxygen can cause lung injury and lead to pulmonary fibrosis. Angiotensin (Ang) II induces human lung fibroblast proliferation and stimulates collagen synthesis. However, the role of the renin-angiotensin system (RAS) in the pathogenesis of hyperoxia-induced collagen production is unclear. The aims of this study were to investigate the effects of hyperoxia on the components of the RAS and collagen expression in human lung fibroblasts (MRC-5). Hyperoxia increased total collagen, collagen type I, and alpha-smooth muscle actin (alpha-SMA) mRNA and protein expression. RAS components and Ang II production were also significantly increased after hyperoxic exposure. Hyperoxia induced Ang II type 1 receptor (AT1R) expression but did not alter AT2R expression, furthermore, silencing of AT1R signaling with small interfering RNA suppressed hyperoxia-induced phosphorylated-ERK (p-ERK) 1/2, alpha-SMA, and collagen type I expression. Ang II increased p-ERK 1/2 and collagen type I expression, and these increases were inhibited by the AT1R inhibitor, losartan, but not by the AT2R inhibitor, PD123319 under both normoxic and hyperoxic conditions. These data suggest Ang II-mediated signaling transduction via AT1R is involved in hyperoxia-induced collagen synthesis in human lung fibroblasts.

Impact of diabetes mellitus on the prognosis of patients with oral squamous cell carcinoma: a retrospective cohort study

BACKGROUND

Diabetes mellitus (DM) is a prevalent chronic metabolic disease reported to affect the treatment outcomes of malignancies. This study explores the impact of diabetes on the prognosis of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Clinicopathological characteristics and survival in terms of overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) of patients with OSCC who underwent surgical intervention at the Taipei Veterans General Hospital between 2002 and 2005 were stratified by diabetic status and compared.

RESULTS

Patients with DM tend to have a lower OS, RFS, and CSS compared with nondiabetics (adjusted hazard ratio [HR] = 2.22, 2.42, and 2.16, respectively) even in less aggressive tumor stages (stage I and II). In advanced tumors, diabetic patients who were not prescribed adjuvant therapy had a significantly higher recurrence rate than nondiabetic patients (HR = 2.66). However, there was no significant difference in treatment outcome in patients with locally advanced tumors amenable to receive adjuvant therapy, even with the delayed initiation of adjuvant therapy in the DM group (49.1 +/- 22.3 days vs. 40.0 +/- 16.6 days, P = .04). DM was also associated with a higher frequency of perineural invasion (adjusted odds ratio [OR] = 2.53).

CONCLUSION

DM status could be a prognostic factor for OSCC, particularly for its effect in the survival and perineural invasion. Although diabetes-associated comorbidities may impair decision making toward less aggressive therapeutic modality, adjuvant treatment may be essential for DM patients to improve their survival.

Factors associated with the stability of mini-implants for orthodontic anchorage: a study of 414 samples in Taiwan

PURPOSE

To evaluate failure rates and factors associated with the stability of mini-implants used for orthodontic anchorage.

PATIENTS AND METHODS

We enrolled 166 patients (35 male patients and 131 female patients) who had consecutively received mini-implants for orthodontic anchorage at the Section of Orthodontics and Pediatric Dentistry, Taipei Veterans General Hospital (Taipei, Taiwan) from January 2001 to December 2006. A total of 414 mini-implants with diameters ranging from 1.2 to 2.0 mm were evaluated. Clinical variables for analysis were divided into host-related and implant-related factors. Mini-implants that could be maintained for orthodontic anchorage for more than 6 months were considered to be successful. Statistical analysis was used to evaluate the failure rate in our study cohort and to identify possible associated factors.

RESULTS

The overall failure rate was 10.1% (42 of 414 screws) with orthodontic force loading for more than 6 months. Most failures were due to loosening and occurred within the first 2 weeks. Differences in overall failure rates for the maxilla and mandible (9.3% and 16.3%, respectively) were not statistically significant. A lower failure rate was found for the maxilla with implant diameters equal to or less than 1.4 mm (P = .036). The left side had a lower failure rate than the right (6.7% vs 13.9%, P = .019). Length and type of mini-implants, age, and gender were not associated with mini-implant failure.

CONCLUSIONS

Use of mini-implants for anchorage is reliable. In our study the overall success rate was 89.9%. Careful diameter selection for different locations is essential. In the maxilla an implant diameter equal to or less than 1.4 mm is recommended. In the mandible an implant diameter larger than 1.4 mm is suggested for better orthodontic anchorage. Hygienic care of implantation sites should also be emphasized for long-term success of mini-implant anchorage.

Murine B16 melanoma vaccination-induced tumor immunity: identification of specific immune cells and functions involved

Vaccination using inactivated B16 melanoma cells that have been treated in vitro for > 2 weeks with interferon-alpha (IFN-alpha) (B16alpha cells) has been shown to elicit a protective host antitumor immunity. In these studies, vaccination with B16alpha cells has been shown to provide protection against primary B16 tumor challenge, established B16 tumors, and metastatic B16 tumors. Specific immune cells and factors that might mediate this tumor immunity have now been evaluated. Macrophage depletion studies suggest that macrophage function is required for expression of tumor immunity either for processing of antigen or for cytokine production but that macrophage function is not involved in direct cytotoxicity against the B16 challenge tumor. CD8(+) T cell depletion studies show that cytotoxic T cell function is required for expression of tumor immunity. Syngeneic knockout mouse experiments offer further insights into the immune cells and factors that mediate the development and expression of tumor immunity. First, interleukin-12 (IL-12) knockout mouse experiments identify IL-12 as an important cytokine in mediating the development of tumor immunity. Second, specific knockout mouse experiments show that tumor immunity requires the function of CD4(+) T cells, CD8(+) T cells, and natural killer (NK) cells. Third, specific knockout mouse experiments show that tumor immunity does not require the function of B cells. The results suggest that vaccination with inactivated B16alpha cells induces an active, cell-mediated immunity to B16 melanoma cells. The tumor vaccination protocol with B16alpha cell vaccinations establishes a potent tumor immunity against B16 melanoma tumors in mice and may serve as a model for induction of tumor immunity against primary or secondary melanoma tumors in humans.

Solid-phase synthesis of 2,3,5-trisubstituted indoles

2,3,5-Trisubstituted indoles are synthesized in three steps starting from resin-bound aniline 2. R1 is introduced by a palladium-mediated coupling of the aryl iodide with terminal alkynes followed by intramolecular cyclization to form the indole core. Acylation at C-3 with an acid chloride in the presence of AlCl(3) catalyst introduces R2. The indole C-5 position is then diversified either by Sonagashira or Suzuki couplings with the aryl bromide. Finally, indole N-1 can be modified by post-cleavage methylation. [reaction: see text]

Disseminated cutaneous infection with Mycobacterium kansasii: genotyping versus phenotyping

Mycobacterium kansasii is a common and virulent pathogen. However, primary cutaneous M kansasii infection has rarely been reported, totaling to only 34 cases since 1965. This low incidence has not been explained, but probably is due to difficulty in culture or phenotyping. We describe the first reported case of cutaneous M kansasii diagnosed by genotyping, which is based on the DNA extracted from the formalin-fixed and paraffin-embedded tissue.

Sequence polymorphism in the coding region of mitochondrial genome encompassing position 8389-8865

Analysis of the polymorphic sequences in mitochondrial DNA (mtDNA) has been widely applied to forensic tests and anthropology studies. However, these polymorphic data in human have thus far been derived from the displacement-loop and intergenic regions only. Here, we report the identification of clustered polymorphic sites in the mitochondria coding region encompassing position 8389-8865. The DNA sequences of 119 unrelated Chinese were determined by PCR amplification and direct sequencing. The results showed that heteroplasmy was found in five individuals, 39 sites were noted in this 477 bp region, and 41 haplotypes were identified. The probability of identity and allelic diversity were estimated as 0.1265 and 0.8809, respectively. The results suggest that sequence polymorphism from position 8389-8865 in human mtDNA can be used as a marker for identity investigation.

Growth of immigrant Chinese infants in the first year of life

PURPOSE

To understand the growth patterns of Chinese-American infants from birth to 1 year old.

METHODS

Retrospective cohort design comparing the growth patterns of 163 Chinese infants living in Ann Arbor, Michigan, and 158 Chinese infants living in Taipei, Taiwan. All infants were born at full-term, without major medical illnesses.

RESULTS

Chinese-American infants were significantly heavier and longer than Taiwanese infants for all age groups and for both genders. Chinese-American infants were born at average weights, rose to the 70th to 80th percentile between 2 and 6 months, and declined to the 50th percentile or less at 9 to 12 months (when measured by American growth charts). When these infants' lengths and weights are plotted on Taiwan's growth curves, no such fluctuations were seen.

CLINICAL IMPLICATIONS

Our findings suggest that rapid weight gain in Chinese-American infants in the first 6 months after birth can be expected, and may then lessen. By the first year, on average, these infants' weights will be < 50th percentile using the American National Center for Health Statistics growth standard. These findings can reassure health providers and help them to provide sound nutritional recommendations and counselling to parents.

Tubulointerstitial nephritis associated with a novel mitochondrial point mutation

BACKGROUND

Nephropathy caused by mitochondrial disorders is a relatively newly recognized disease. Only a few cases have been reported in the literature, and most of them are proximal tubulopathy-presenting Fanconi syndrome. Here we report on a novel mutation in two familial cases of tubulointerstitial nephropathy associated with concentrating defect.

METHODS

Renal biopsy specimens were examined by light microscopy and electron microscopy. Mitochondrial genomic DNA isolated from renal biopsy specimens was amplified by polymerase chain reaction (PCR) and sequenced in its entirety. The DNA sequences were analyzed by (1) comparing with the Anderson et al's mitochondrial sequences; (2) comparing with DNA sequences obtained from 97 human controls, including both healthy individuals and patients with renal diseases; and (3) comparing with the counterparts in 90 different species.

RESULTS

Dismorphic mitochondria with occasional intramitochondrial inclusions were found in the renal tubular epithelial cells. A novel mitochondrial point mutation was identified at the position 608, that is, the distal end of the anticodon stem of the tRNA(Phe) molecule. The A to G substitution at this position was not observed in 97 human controls and was found to be highly conserved in evolution.

CONCLUSIONS

We have identified an A608G mutation of mitochondrial genome in two cases whose presentation include tubulointerstitial nephritis and stroke.

Expression of highly controllable genes in insect cells using a modified tetracycline-regulated gene expression system

A modified tetracycline-responsive expression system (TRES) for use in insect cells was developed. The TRES contains two components: one encodes a tetracycline-controllable transactivator (tTA) and the other contains a tet operator DNA sequence to drive the luciferase gene. Our results show that the human cytomegalovirus (CMV) promoter, an essential part for strong tTA expression in mammalian system, was not functional in insect cells. Thus further modifications were required. Functional tTA was efficiently expressed in Sf9, Sf21, and TN368 cells by the p10 promoter of Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) in plasmid form with virus co-infection. An increase of up to 258-fold of luciferase activity was detected in these cells when both components in modified TRES were co-transfected. In order to further simplify the experiment, tTA, which is driven by the p10 promoter, was inserted into AcMNPV. Luciferase activity was also strongly stimulated by the infection of this tTA expression-recombinant virus with the transfection of a plasmid containing the second TRES component expressing luciferase. The luciferase expressions in these systems, either in plasmids or the tTA gene in virus and luciferase in plasmid, were significantly suppressed by tetracycline. The time course kinetics of tetracycline action to the TRES were further studied. Within a time span of 50 h, the luciferase activities could be fully suppressed or activated, respectively, corresponding to the addition or removal of tetracycline. These experiments have established a well-regulated gene expression system for further broad applications of molecular biological studies in insect cells.

Enhancement of radiosensitivity in human glioblastoma U138MG cells by tetrandrine

Tetrandrine, a natural lipid-soluble alkaloid with a low molecular weight, has both anti-tumor activity and a tissue-protective effect, as demonstrated in our previous studies. We studied tetrandrine to determine whether or not it enhanced radiosensitivity in human glioblastoma U138MG cells. Tetrandrine at concentration of 5.0 and 7.5 eg/ml dramatically enhanced the growth-inhibiting effect of radiation. This effect is dose-dependent on the dose of both tetrandrine and radiation. Moreover, we found that tetrandrine eliminated the cell cycle perturbation induced by radiation. Cells treated with tetrandrine alone as well as with a combination of tetrandrine and radiation became rounded, floated up and grew sparsely under observation under an inverted light microscope, DNA fragmentation was also noted by gel electrophoresis. These findings suggest that tetrandrine has potential as an adjunct to radiotherapy for glioblastoma.

Efficacy of B16 melanoma cells exposed in vitro to long-term IFN-alpha treatment (B16alpha cells) as a tumor vaccine in mice

B16 melanoma cells exposed to >2 weeks of in vitro interferon-alpha (IFN-alpha) treatment (B16alpha cells) were UV inactivated and used for vaccination. This vaccination was efficacious against challenge with parental B16 cells in the absence of adjuvant therapy. Vaccinations based on parental cells and B16 cells exposed to short-term in vitro IFN-alpha treatment were not effective. The efficacy of B16alpha vaccination was evaluated using three B16 tumor models. Using intraperitoneal (i.p.) tumor challenge given after vaccination, vaccination efficacy depended on the concentration of IFN-alpha to which B16alpha cells were exposed, the number of inactivated B16alpha cells inoculated, the number of inoculations administered, and the amount of tumor burden. A significant fraction (30%) of vaccinated mice surviving initial challenge had durable immunity against a second parental tumor challenge. This immunity increased to 92% with administration of a single booster vaccination. Using metastatic tumor challenge given after vaccination, vaccination reduced lung metastases by approximately 67%. Using vaccination begun 3 days after subcutaneous (s.c.) tumor challenge, regression of established tumor occurred when vaccination was given i.p. (39%) or contralaterally s.c. (53%). Taken together, the results suggest that vaccination with inactivated B16alpha cells may serve as a model for induction of host tumor immunity against primary or secondary tumors.

Use of sodium polystyrene sulfonate for reduction of plasma lithium concentrations after chronic lithium dosing in mice

OBJECTIVES

Previous studies have shown that oral sodium polystyrene sulfonate lowers plasma lithium concentrations after acutely administered oral doses of lithium chloride. However, a significant proportion of lithium overdose cases resulting in morbidity and mortality are those in which exposure to lithium is chronic. This study was designed to determine whether multiple oral doses of sodium polystyrene sulfonate are effective in reducing plasma lithium concentrations after chronic dosing.

DESIGN

Placebo-controlled animal study.

INTERVENTIONS

One hundred thirty mice were given 75 mM lithium chloride in their drinking water for a period of 14 days. At the end of that period, half of the animals were given orogastric sodium polystyrene sulfonate at 5 g/kg/dose 0, 60, 120, 180, and 360 minutes after the cessation of lithium chloride; the remaining half received orogastric water at equivalent times. Subgroups of each group were sacrificed at 90, 150, 330, 480, 1440, and 2880 minutes after lithium chloride cessation and plasma analyzed for lithium content. Lithium concentrations were compared by analysis of variance and single degree of freedom contrasts. Significance was set at an alpha level of 0.05.

RESULTS

Lithium concentration was lower overall in the animals treated with sodium polystyrene sulfonate (p < .0001) and specifically at 150, 330, and 480 minutes after lithium chloride cessation (p < .05).

CONCLUSIONS

Repetitive oral doses of sodium polystyrene sulfonate effectively lowered plasma lithium concentrations. Further study may ultimately define a role for the use of sodium polystyrene sulfonate in the treatment of patients with chronic lithium toxicity.

A 2.9-kilobase noncoding nuclear RNA functions in the establishment of persistent Hz-1 viral infection

Differential viral gene expression during both productive and persistent infections of Hz-1 virus in insect cells was elucidated. Despite more than 100 viral transcripts being expressed during productive viral infection, massive viral gene shutoff was observed during viral persistency, leaving the 2.9-kb persistence-associated transcript 1 (PAT1) as the only detectable viral RNA. Persistence-associated gene 1 (pag1), which encodes PAT1, was cloned and found to contain no significant open reading frames. PAT1 is not associated with the cellular translation machinery and is located exclusively in the nucleus. Further experiments showed that PAT1 is functional in the establishment of persistent Hz-1 viral infection in the cells. All the evidence collectively indicates that PAT1 is a novel nuclear transcript of viral origin. Our results showed that although PAT1 and XIST RNA, a mammalian X-inactive specific transcript, are transcribed by different genes, they have interesting similarities.

Induction of apoptosis in human leukemic U937 cells by tetrandrine

Tetrandrine, a calcium channel antagonist, is a plant alkaloid possessing various pharmacological activities including anti-tumor activity. We studied tetrandrine to determine whether or not this anti-tumor effect occurs through induction of apoptosis. Tetrandrine inhibited both proliferation and clonogenicity of human leukemic U937 cells at an optimal concentration of 2.5 microg/ml. This growth inhibition was dose and time dependent, and accompanied with evidence of apoptotic changes. The characteristic morphological changes of apoptosis were observed in U937 cells under light microscopy and DNA fragmentation was noted by gel electrophoresis. Moreover, flow cytometric detection of surface phosphatidyl serine expression of U937 cells after treatment with tetrandrine confirmed the induction of apoptosis in these cells. The induction of apoptosis by tetrandrine would appear to proceed via non-Ca2+-dependent pathways.

Orally administered IFN-alpha acts alone and in synergistic combination with intraperitoneally administered IFN-gamma to exert an antitumor effect against B16 melanoma in mice

Administration of interferons (IFN) via the intranasal route recently has been shown to exert an antitumor activity against a variety of tumors in mice, including B16 melanoma inoculated intravenously. This study confirms the antitumor activity of orally administered IFN-alpha against B16 melanoma challenge using another route of tumor inoculation, the intraperitoneal route. It further demonstrates that orally administered IFN-alpha can synergistically interact with intraperitoneally administered IFN-gamma but not with intraperitoneally administered IFN-alpha. The results support the interpretation that the oral route may provide an effective alternative or supplement to current methods of IFN administration for the control of malignancies.

Exercise performance of Tibetan and Han adolescents at altitudes of 3,417 and 4,300 m

The difference was studied between O2 transport in lifelong Tibetan adolescents and in newcomer Han adolescents acclimatized to high altitude. We measured minute ventilation, maximal O2 uptake, maximal cardiac output, and arterial O2 saturation during maximal exercise, using the incremental exercise technique, at altitudes of 3,417 and 4,300 m. The groups were well matched for age, height, and nutritional status. The Tibetans had been living at the altitudes for a longer period than the Hans (14.5 +/- 0.2 vs. 7.8 +/- 0.8 yr at 3,417 m, P < 0.01; and 14.7 +/- 0.3 vs. 5.3 +/- 0.7 yr at 4,300 m, P < 0.01, respectively). At rest, Tibetans had significantly greater vital capacity and maximal voluntary ventilation than the Hans at both altitudes. At maximal exercise, Tibetans compared with Hans had higher maximal O2 uptake (42.2 +/- 1.7 vs. 36.7 +/- 1.2 ml . min-1 . kg-1 at 3,417 m, P < 0.01; and 36.8 +/- 1.9 vs. 30.0 +/- 1. 4 ml . min-1 . kg-1 at 4,300 m, P < 0.01, respectively) and greater maximal cardiac output (12.8 +/- 0.3 vs. 11.4 +/- 0.2 l/min at 3,417 m, P < 0.01; 11.5 +/- 0.5 vs. 10.0 +/- 0.5 l/min at 4,300 m, P < 0. 05, respectively). Although the differences in arterial O2 saturation between Tibetans and Hans were not significant at rest and during mild exercise, the differences became greater with increases in exercise workload at both altitudes. We concluded that exposure to high altitude from birth to adolescence resulted in an efficient O2 transport and a greater aerobic exercise performance that may reflect a successful adaptation to life at high altitude.

B16 melanoma cells exposed in vitro to long-term IFN-alpha treatment (B16 alpha cells) as activators of tumor immunity in mice

Mice inoculated with B16 melanoma cells exposed to long-term in vitro IFN-alpha treatment (> or = 14 days, B16 alpha cells) but not short-term in vitro IFN-alpha treatment (24 h) exhibited an enhanced survival time. Enhanced survival time also occurred when inactivated B16 alpha cells were inoculated at the same time as live B16 cells. Further, an even greater improvement in survival time was observed when the inactivated B16 alpha cells were inoculated before live B16 cell challenge. No enhancement in survival time was observed when mice were inoculated with inactivated, untreated B16 cells. Enhancement of survival time by B16 alpha cells was unrelated to retrovirus surface antigen expression. Long-lasting protective immunity to B16 cells was observed in mice that survived B16 alpha cell, but not normal B16 cell, challenge and subsequent IFN treatment. It is evident that inoculation with inactivated B16 alpha cells, but not with inactivated untreated B16 cells, was able to prolong significantly the survival time of mice either simultaneously or subsequently challenged with live B16 cells. Additionally, survival of B16 alpha-inoculated but not B16-inoculated mice was accompanied by a durable immunity. Inoculation of inactivated B16 alpha cells may serve as a model for the induction of host immunity to a parental primary or secondary tumor.

A study of the oligomeric state of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-preferring glutamate receptors in the synaptic junctions of porcine brain

The number of the subunits in an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-preferring L-glutamate receptor in the synaptic junctions of porcine brain was investigated in this study. Upon incubation of the synaptic junctions with three cross-linking regents, dimethyl adipimidate (DMA), dimethyl suberimidate (DMS) and N-succinimidyl-(4-azidophenyl)-1,3'-dithiopropionate (SADP), AMPA receptor subunits in higher-molecular-mass aggregates were detected by immunoblotting. These aggregates migrated as proteins of approx. 200, 300 and 400 kDa. The number and identity of the subunits in a solubilized AMPA receptor were also investigated here. Two samples, W1 and W2, enriched in AMPA receptors were prepared from synaptic junctions by a combination of detergent-solubilization, anion-exchange chromatography and wheatgerm agglutinin affinity chromatography. Hydrodynamic behaviour analyses revealed that the majority of the AMPA receptors in either one of these samples were asymmetrical detergent-surrounded particles with a protein mass around 350 kDa. SDS/PAGE analysis revealed that the majority of AMPA receptors in the W1 sample were comprised of dimers of 106 kDa subunits which were covalently linked by disulphide bonds. Cross-linking these receptors with SADP yielded a new band of approx. 400 kDa. The results obtained here, either from the studies of AMPA receptors embedding in synaptic junctions or from those of detergent-solubilized and partially purified receptors, suggest that AMPA receptors contain a basic core structure comprising of four 106 kDa subunits.

Purification and biochemical characterization of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate-sensitive L-glutamate receptors of pig brain

Two preparations of glutamate receptors were purified from the synaptic junctions of pig brain by a combination of detergent solubilization, anion-exchange chromatography, wheat-germ agglutinin affinity chromatography and sedimentation through sucrose gradients. These preparations were enriched in specific L-[3H]glutamate binding activity (> 5000 pmol of glutamate binding sites/mg of protein), and the rank order of ligand affinity for binding to these preparations was: quisqualate > 6-cyano-7- nitroquinoxaline-2,3-dione > alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) > L-glutamate > kainate > > N-methyl-D-aspartate approximately L-2-amino-4-phosphonobutyrate. SDS/PAGE analysis revealed that more than 80% of the protein in either of these preparations appeared as a single protein band of 106 kDa. Two-dimensional gel electrophoresis further revealed that these 106 kDa proteins consisted of a series of acidic proteins which were recognized by antibodies against rat AMPA receptor subunits. These 106 kDa proteins were also recognized by wheatgerm agglutinin and concanavalin A; in addition, peptide N-glycosidase F treatment of these preparations decreased their size to 99 kDa. Our results suggest that the putative glutamate receptors isolated here are likely to belong to the AMPA subtype of glutamate receptors in pig brain. Using the purification procedure reported here, 5 micrograms of AMPA receptor proteins can be isolated from 250 g of pig brain tissue.

Optimal solutions for cellular neural networks by paralleled hardware annealing

An engineering annealing method for optimal solutions of cellular neural networks is presented. Cellular neural networks are very promising in solving many scientific problems in image processing, pattern recognition, and optimization by the use of stored program with predetermined templates. Hardware annealing, which is a paralleled version of mean-field annealing in analog networks, is a highly efficient method of finding optimal solutions of cellular neural networks. It does not require any stochastic procedure and henceforth can be very fast. The generalized energy function of the network is first increased by reducing the voltage gain of each neuron. Then, the hardware annealing searches for the globally minimum energy state by continuously increasing the gain of neurons. The process of global optimization by the proposed annealing can be described by the eigenvalue problems in the time-varying dynamic system. In typical nonoptimization problems, it also provides enough stimulation to frozen neurons caused by ill-conditioned initial states.

Hydrodynamic and pharmacological characterization of putative alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate-sensitive L-glutamate receptors solubilized from pig brain

L-[3H]Glutamate binding sites with characteristics resembling that of membrane-bound alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate-subtype L-glutamate receptors have been solubilized from pig brain synaptic junctions by Triton X-114. Binding of [3H]AMPA to these soluble sites in the presence of KSCN results in a curvilinear Scatchard plot that can be resolved into a high-affinity component and a low-affinity component. These Triton-X-114-solubilized sites can be further separated into two species of binding sites by gel-filtration chromatography or sucrose-density-gradient centrifugation. The pharmacological profiles of these two species of binding site are almost identical, and the rank orders of potency for glutamatergic drugs in displacing L-[3H]glutamate binding to these sites are quisqualate > 6,7-dinitroquinoxaline-2,3-dione > 6-cyano-7-nitroquinoxaline-2,3-dione > AMPA > L-glutamate > kainate >> N-methyl-D-aspartate = L-2-amino-4-phosphonobutyrate. Both sites are found to bind [3H]AMPA, and in the presence of KSCN the binding activities are significantly enhanced. Analysis of the hydrodynamic behaviour of these binding sites by sucrose-density-gradient centrifugation in H2O- and 2H2O-based solvents and gel-filtration chromatography has revealed that one of these sites (Stokes radius 8.3 nm, sedimentation coefficient 18.5 S) consists of 562 kDa protein and 281 kDa detergent, and the other site (Stokes radius 9.6 nm, sedimentation coefficient 13.4 S) consists of 352 kDa protein and 569 kDa detergent. Frictional coefficients of these sites indicate that these receptor-detergent complexes are asymmetrical in structure, consistent with large transmembrane proteins.

Effects of high altitudes on finger cooling test in Japanese and Tibetans at Qinghai Plateau

The influences of both hypobaric hypoxia and cold on peripheral circulation were studied using the finger cooling test (measurement of the decrease in finger temperature, measured at the dorsal surface of the finger, during immersion of the hand in 0 degrees C water for 20 min) at Qinghai Plateau. The same test was carried out at simulated altitudes in a 25 degrees C climatic chamber to separate the hypobaric hypoxia influence from that of cold. In Japanese subjects at Qinghai Plateau there was a significant difference between finger skin temperatures (FSTs) during 20 min of 0 degrees C water immersion at altitudes of 2260 m and 4860 m by ANOVA. Mean finger skin temperature during the 20-min immersion (5-20 min, MST) measured at 4860 m was significantly lower than that at 2260 m. In Tibetan subjects, there was also a significant difference between FSTs at 2260 m and at 4860 m by ANOVA. MST at 4860 m tended to be lower than that at 2260 m. In the 25 degrees C climatic chamber, there was a significant difference between FSTs of Japanese expedition members at 2000 m and at 4000 m by ANOVA. MST was higher at 4000 m than at 2000 m, contrary to the data obtained in Qinghai. In conclusion, the higher skin temperature in response to local cold immersion, which would have been caused by stronger hypobaric hypoxia, must have been masked by the lower ambient temperature.

Localization of specific repetitive DNA sequences in individual rice chromosomes

This paper describes the characterization and chromosomal distribution of three different rice (Oryza sativa) repetitive DNA sequences. The three sequences were characterized by sequence analysis, which gave 355, 498 and 756 bp for the length of the repeat unit in Os48, OsG3-498 and OsG5-756, respectively. Copy number determination by quantitative DNA slot-blot hybridization analysis showed 4000, 1080 and 920 copies, respectively, per haploid rice genome for the three sequences. In situ DNA hybridization analysis revealed that 95% of the silver grains detected with the Os48 probe were localized to euchromatic ends of seven long arms and one short arm out of the 12 rice chromosomes. For the OsG3-498 repetitive sequence, the majority of silver grains (58%) were also clustered at the same chromosomal ends as that of Os48. The minority (28%) of silver grains were located at heterochromatic short arms and centromeric regions. For the OsG5-756 repetitive sequence, 81% of the silver grains labeled the heterochromatic short arms and regions flanking all of the 12 centromeres. Thus, each of these three repetitive sequences was distributed at specific defined chromosomal locations rather than randomly at many chromosomal locations. The approximate copy number of a given repetitive DNA sequence at any specific chromosomal location was calculated by combining the information from in situ DNA hybridization analysis and the total copy number as determined by DNA slot-blot hybridization.

A new rice repetitive DNA shows sequence homology to both 5S RNA and tRNA

Moderately repetitive DNA sequences are found in the genomes of all eucaryotes that have been examined. We now report the discovery of a novel, transcribed, moderately repetitive DNA sequence in a higher plant which is different from any of the known repetitive DNA sequences from any organism. We isolated a rice cDNA clone which hybridizes to multiple bands on genomic blot analysis. The sequence of this 352 bp cDNA contains four regions of homology to the wheat phenylalanine tRNA, including the polymerase III-type promoter. Unexpectedly, two regions of the same 352 bp sequence also show homology to the wheat 5S RNA sequence. Using the cDNA as a probe, we have isolated six genomic clones which contain long tandem repeats of 355 bp sequence, and have sequenced nine repeat units. Our findings suggest that the rice repetitive sequence may be an amplified pseudogene with sequence homology to both 5S RNA and tRNA, but organized as long tandem repeats resembling 5S RNA genes. This is the first example showing homology between the sequences of a moderately repetitive DNA with unknown function and 5S RNA.