Using QuEChERS and HPLC Method to Monitor the Background Concentration of Polycyclic Aromatic Hydrocarbons in Commercial Black Tea Leaves and Infusions in Taiwan

Tea is an integral part of Taiwanese culture and is a popular drink as it contains many beneficial compounds. However, during the processing of tea, polycyclic aromatic hydrocarbons (PAHs) may form. This study investigated the concentrations of PAH4 in different black tea leaves and tea infusions based on the origin of the tea. The samples were extracted using QuEChERS, while the content of PAH4 was analyzed by high performance liquid chromatography coupled to a fluorescence detector (HPLC-FLD). The content of PAH4 in the tea leaves ranged from 2.88 µg/kg to 218.2 µg/kg (dry weight), with the highest concentration being found in teas from Vietnam. The concentration of BaP ranged from ND to 47.92 µg/kg. The release of PAH4 from tea leaves to tea infusions was significantly low, with the highest transfer being 25.8%. In this study, all PAH4 compounds in commercial black tea leaves can be detected by QuEChERS extraction with a simple HPLC method.

Dietary Exposure and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Black Tea Consumed in Taiwan

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds found in many foods and drinks, and there have been some concerns over these compounds due to their carcinogenic nature. This study evaluated the concentrations of PAH4 (BaP, BaA, BbF, and CHR) in different black tea infusions and drinks based on the origin of the tea. The release of PAH4 from tea leaves to tea infusions was significantly low, with the highest transfer being 25.81%. The mean concentrations of BaP and PAH4 in tea infusions were used to conduct a risk assessment for the Taiwanese population, which showed that the 19-65 age group had the highest estimated intake of PAH4 and BaP among all age groups. These results, however, also showed margin of exposure (MOE) values well above the benchmark of 10,000. This indicated that PAH exposure from black tea consumption for the Taiwanese population constitutes a low-level health concern.

Estimating arsenic biotransfer factors from feed to chicken: a viable approach to animal feed risk assessment

Reliable biotransfer factor (BTF) data are critical for animal-feed studies in human risk assessment. A wide range of BTF values have been reported (0.0015-0.83 d/kg), expressed as the ratio of total arsenic (tAs) concentration (µg/kg) in chicken to daily intake rate (µg/d) of tAs in feed (tAs/tAs). Data on inorganic As (iAs) for chicken meat and tAs concentrations for feed were obtained from our related study. Using the linear regression technique developed in this study, we estimated the BTF as 0.016 d/kg, as iAs/tAs (R² > 0.7702) and 0.55 d/kg as tAs/tAs (R² =  0.9743) for whole chicken meat. From a mass-balance perspective, we suggest that tAs be used as the denominator for the BTF unit. To illustrate our feed-risk assessment method, we analyzed commercial feeds for tAs concentration (n = 79). Consumption data for the general population (n = 2479) were obtained from a Taiwanese total diet study. Bivariate Monte Carlo simulations (n = 10,000) showed that the 95^th percentile (P95) of estimated daily intake (EDI) was 0.002 µg/kg body weight (bw)/d as iAs (< the benchmark dose lower limit of 3.0 µg/kg bw/d). Our results thus show that the commercial chicken feeds assessed in this study are of low health concern for the general Taiwanese population. We discuss the factors that may have affected the assessment, such as the type of animals investigated, type of feeds, feed tested, type of chemical species used for BTF estimation and statistical approach.

Protective Effect of Hawthorn Fruit Extract against High Fructose-Induced Oxidative Stress and Endoplasmic Reticulum Stress in Pancreatic β-Cells

Hyperglycemia has deleterious effects on pancreatic β-cells, causing dysfunction and insulin resistance that lead to diabetes mellitus (DM). The possible causes of injury can be caused by glucose- or fructose-induced oxidative and endoplasmic reticulum (ER) stress. Hawthorn (Crataegus pinnatifida) fruit has been widely used as a hypolipidemic agent in traditional herbal medicine. The study aimed to investigate whether high fructose-induced pancreatic β-cell dysfunction could be reversed through amelioration of ER stress by the treatment of polyphenol-enriched extract (PEHE) from hawthorn fruit. The extract was partitioned using ethyl acetate as a solvent from crude water extract (WE) of hawthorn fruits, followed by column fractionation. The results showed that the contents of total polyphenols, flavonoids and triterpenoids in PEHE could be enhanced by 2.2-, 7.7- and 1.1-fold, respectively, in comparison to the original obtained WE from hawthorn fruit. In ER stress studies, a sharp increase in the inhibitory activity on the gene expression levels of GRP79, ATF6, IRE1α and CHOP involved in ER stress was evident when dosages of PEHE at 50–100 μg/mL were used against high-fructose (150 mM)-treated cells. HPLC–MS/MS analysis showed that polyphenols and flavonoids collectively accounted for 87.03% of the total content of PEHE.

[Attention should be paid to glaucoma following pediatric cataract surgery]

Glaucoma following cataract surgery is one of the common complications after pediatric cataract surgery, and it is the main cause of "second blindness" in children. Since this atypical disease is difficult to diagnose and evaluate, it has been gradually paid more attention by clinicians. There are still some controversies and challenges related to the characteristics of the disease, diagnostic criteria, and treatment options. This article discusses the definition, diagnostic criteria, related risk factors, treatment strategies, follow-up, and prognoses of glaucoma following cataract surgery. Establishment of a diagnosis and treatment system can better improve the visual rehabilitation of pediatric cataract children.

Dietary exposure assessment of methylmercury and polyunsaturated fatty acids in saltwater fish and processed foods among Taiwanese women of child-bearing age and children: A novel core food-matching approach

Saltwater fish is rich in health-promoting polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Excessive fish intake may also cause health hazards due to methylmercury (MeHg). A novel dose estimation method was proposed in this study to improve the quality of food matching by considering the usage ratio of cooking and processing methods in sampling design. In total, 39 table-ready samples were specified according to 2-3 common cooking methods, and MeHg and total mercury (THg) were analyzed. The results showed that mercury was detected in 20 samples (LOD = 0.01 μg/g). High MeHg samples included fried-Spanish mackerel (1.23 μg/g), non-cooked shredded swordfish (0.325 μg/g), pan-fried Spanish mackerel (0.248 μg/g), and non-cooked shredded salmon (0.208 μg/g). Consumption data (n = 166,911) were obtained from 24-h recalls in the 2005-2008 Nutrition and Health Surveys in Taiwan (NAHSIT). The average whole-group estimated daily intake (EDI_WG) was 0.018 (7.9% tolerable daily intake, TDI) for women of child-bearing age and 0.031 μg/day per kg body weight (13.6% TDI) for children. However, 95th percentile values (P95) of 90.4% TDI and 185% TDI were estimated for the two consumer-only populations, which have raised public health concerns. The ratio of % TDI to % daily reference intake (% DRI) was used as a risk-benefit (R/B) indicator. The top 4 R/B foods were: tuna sashimi (0.089 and 0.14), non-cooked shredded swordfish (0.033 and 0.052), fried-Spanish mackerel (0.027 and 0.043) and deep-fried fish balls (0.022 and 0.035) in the two perspective populations.

Effects of Hsian-tsao (Mesona procumbens Hemsl.) extracts and its polysaccharides on the promotion of wound healing under diabetes-like conditions

Hsian-tsao extracts and its polysaccharides accelerate wound healing in cell models and diabetic mice.

Potential effect of advanced glycation end products (AGEs) on spermatogenesis and sperm quality in rodents

The aim of the present study was to assess whether dietary advanced glycation end products (AGEs) induce testicular dysfunction. Using a BALB/c mouse model, AGE intake and serum levels were found to increase in AGE diet-treated mice relative to the controls. Histopathological damage was detected in the testes and epididymides of the AGE diet-induced mice. The total number of epididymal sperm decreased, and increased abnormal sperm rate was found in the mice. Moreover, the mice testes showed an increased level of the receptor for AGEs (RAGE) and malondialdehyde (MDA). Using a Sprague-Dawley rat model, AGE diet-induced rats showed 3- to 4-fold higher AGE intake than the controls. In these rats, higher serum and sperm MDA levels, decreased epididymal sperm numbers, and increased abnormal sperm rates were also observed. Silymarin, a natural AGE inhibitor, was found to restore these AGE-induced phenomena. Concluding from the above findings, dietary AGEs may promote testicular dysfunction.

The Integration of Recipes with a Standardizable Food Description FACET for Cadmium Exposure Risk Assessment

Existing food classification and description systems provide users with limited information related to exposure assessment. Our aim in this work is to propose a standardized food description facet called the Taiwan Food Recipe (TFR) system as an emerging tool for food composition, with detailed food ingredient information, including names, proportions, weights of uncooked and cooked foods, etc. The composite foods listed in the Taiwan Nutrition and Health Survey were collected into a list and as consumption data. The TFR system is intended to help analysts reduce potential estimation bias, where, for example, risk assessment results may be overestimated or underestimated due to the complexity of the composition in the composite foods. Based on a Taiwanese food database, we further illustrate and demonstrate how the TFR system can be applied to the assessment of risk of cadmium (Cd) exposure in rice ingredients in the composite food products. In the original system (HFDFC system), the composite food intakes used total weight to estimate the hazard index (HI) of cadmium in the exposure risk assessment, but the percentage of rice was not 100%. The proposed TFR system estimates the percentage of rice and actual intakes in composite foods. Fried rice, sushi, and rice balls in the study were the most common foods containing rice and had higher consumption rates among Taiwan’s rice-based composite foods. The HIs of fried rice, sushi, and rice balls were 0.09, 0.10, and 0.13, respectively, in the HFDFC system. In the TFR system, the HIs of rice in fried rice, sushi, and rice balls were 0.06, 0.04 and 0.05, respectively. The HI of other components in fried rice, sushi, and rice balls were 0.03, 0.06 and 0.08, respectively. More precise HIs were thus shown. The TFR system contributes to global food classification and description systems by providing an appropriate, standardized, and generalized framework for exposure assessments.

Application of food description to the food classification system: Evidence of risk assessment from Taiwan as Acrylamide of grain products

Harmonization of national consumption data for international comparison is an important but challenging work, yet to date there is a lack of comparable food classification system that incorporates food description in Taiwan. In 2015, European Food Safety Authority (EFSA) released a new standardized food classification and description system called FoodEx2, which provides a flexible combination of classifications and descriptions. Based on FoodEx2 and a unique data set of daily food consumption offered by Taiwan Food Consumption Database, this study aims to provide a harmonized, food description incorporated, food classification system (HFDFC system) that captures all the useful details of food groups in exposure assessments. The HFDFC system was built according to six risk-assessment-related facets including food sources, processed products, cooking methods, manufacturers (brand), food additives and specialty foods. The HFDFC system includes 199 foods in the core list and 131 foods in the extended list. This study also compared the Acrylamide hazard index estimated under the HFDFC system with that under the National Food Consumption Database in Taiwan (NFCDT). The findings indicated that the HFDFC system provides useful and detailed information that helps the users to quickly identify food information in a harmonized manner and to reduce estimation bias. The HFDFC system is expected to facilitate global comparisons in the food risk assessment because it is built based upon EU Foodex2.

[Clinical characteristics and surgical effect observation of congenital aniridia combined with cataract]

Objective: To analyze the clinical manifestations, surgical approaches and postoperative prognosis for the cases of congenital aniridia combined with cataract. Methods: In this retrospective case series, 26 patients diagnosed with congenital aniridia combined with cataract were collected from Zhongshan Ophthalmic Center from February 2002 to August 2016. The Clinical data were collected to analyze the clinical features, surgical approaches and postoperative prognosis. T-test was used for statistical analysis. Results: Twenty-six bilateral congenital aniridia patients were included in the case series, with 50% male cases. The average age for the first visit was (8.72±8.06) years old. Hereditary patients constitutes 30.8% (8/26) of the total number. The proportions for bilateral and unilateral cataracts were 88.5% (23/26) and 11.5% (3/26) respectively, and 49 eyes suffering from both congenital aniridia and cataract were therefore included in the final analysis. The most common morphology cataract subtypes were lamellar cataract (24.5%, 12/49), posterior subcapsular cataract (22.4%, 11/49), and total cataract (18.4%,9/49). The observed ocular comorbidities included nystagmus (36.7%, 18/49), vitreous opacity (28.6%, 14/49), foveal hypoplasia (20.4%, 10/49), ametropia (12.2%, 6/49), exotropia (12.2%, 6/49), congenital glaucoma (12.2%, 6/49), esotropia (4.1%, 2/49), congenital ptosis (4.1%, 2/49), lens ectopia (4.1%, 2/49), scleral staphyloma (2.0%, 1/49) and pigmentary degeneration of retina (2.0%, 1/49). 30.6% (15/49) eyes were performed the cataract extraction surgery. The percentage of postoperative best corrected visual acuity (BCVA) for ≥0.1 and ≥0.3 were 93.3% (14/15) and 20.0% (3/15) respectively. Evaluated ocular pressure (33.3%, 5/15), severe posterior capsular opacification (PCO) (13.3%, 2/15) and choroidal hemorrhage combined with choroidal detachment (6.7%, 1/15) were detected as the postoperative complications. Followed by cataract extraction, 80.0% (12/15) eyes were sequentially performed the intraocular lens implantation, while, 20.0% (3/12) eyes remained aphakia due to ocular comorbidities. Conclusions: Congenital aniridia combined with cataract are rare diseases, calling for the precious retrospective researches. This disorder tended to affect both eyes and occurred hereditary. The clinical courses of the cases presented progressive features. Ocular comorbidities were the crucial factors to influence the surgical approaches and postoperative prognosis. (Chin J Ophthalmol, 2017, 53: 821-827).

Solid-state, ambient-operation thermally activated delayed fluorescence from flexible, non-toxic gold-nanocluster thin films: towards the development of biocompatible light-emitting devices

Luminescent gold nanoclusters (AuNCs) with good biocompatibility have gained much attention in bio-photonics. In addition, they also exhibit a unique photo-physical property, namely thermally activated delayed fluorescence (TADF), by which both singlet and triplet excitons can be harvested. The combination of their non-toxic material property and unique TADF behavior makes AuNCs biocompatible nano-emitters for bio-related light-emitting devices. Unfortunately, the TADF emission is quenched when colloidal AuNCs are transferred to solid states under ambient environment. Here, a facile, low-cost and effective method was used to generate efficient and stable TADF emissions from solid AuNCs under ambient environment using polyvinyl alcohol as a solid matrix. To unravel the underlying mechanism, temperature-dependent static and transient photoluminescence measurements were performed and we found that two factors are crucial for solid TADF emission: small energy splitting between singlet and triplet states and the stabilization of the triplet states. Solid TADF films were also deposited on the flexible plastic substrate with patterned structures, thus mitigating the waveguide-mode losses. In addition, we also demonstrated that warm white light can be generated based on a co-doped single emissive layer, consisting of non-toxic, solution-processed TADF AuNCs and fluorescent carbon dots under UV excitation.

Subchronic Immunotoxicity Assessment of Genetically Modified Virus-Resistant Papaya in Rats

Papaya is an important fruit that provides a variety of vitamins with nutritional value and also holds some pharmacological properties, including immunomodulation. Genetically modified (GM) papaya plants resistant to Papaya ringspot virus (PRSV) infection have been generated by cloning the coat protein gene of the PRSV which can be used as a valuable strategy to fight PRSV infection and to increase papaya production. In order to assess the safety of GM papaya as a food, this subchronic study was conducted to assess the immunomodulatory responses of the GM papaya line 823-2210, when compared with its parent plant of non-GM papaya, Tainung-2 (TN-2), in Sprague-Dawley (SD) rats. Both non-GM and GM 823-2210 papaya fruits at low (1 g/kg bw) and high (2 g/kg bw) dosages were administered via daily oral gavage to male and female rats consecutively for 90 days. Immunophenotyping, mitogen-induced splenic cell proliferation, antigen-specific antibody response, and histopathology of the spleen and thymus were evaluated at the end of the experiment. Results of immunotoxicity assays revealed no consistent difference between rats fed for 90 days with GM 823-2210 papaya fruits, as opposed to those fed non-GM TN-2 papaya fruits, suggesting that with regard to immunomodulatory responses, GM 823-2210 papaya fruits maintain substantial equivalence to fruits of their non-GM TN-2 parent.

Temporal trend of polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran and dioxin like-polychlorinated biphenyl concentrations in food from Taiwan markets during 2004-2012

The levels of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) or polychlorinated biphenyl (PCB) in foodstuffs have decreased over the past decade in many countries. However, the trend for the levels of these compounds in foodstuffs in Taiwan remains unknown. In this study, we compared the distribution of PCDD/F and PCB in nine foodstuff categories acquired from Taiwan markets from 2004 to 2012. The levels expressed as World Health Organization toxic equivalents (WHO-TEQs) in the different foodstuffs tested were as follows: fish, average 0.463 pg WHO₉₈-TEQ/g sample > seafood, 0.163 pg WHO₉₈-TEQ/g > eggs, 0.150 pg WHO₉₈-TEQ/g > oils, 0.126 pg WHO₉₈-TEQ/g > meats, 0.095 pg WHO₉₈-TEQ/g > dairy products, 0.054 pg WHO₉₈-TEQ/g > cereals, 0.017 pg WHO₉₈-TEQ/g > vegetables, 0.013 pg WHO₉₈-TEQ/g > fruits, 0.009 pg WHO₉₈-TEQ/g. Levels were particularly high in crab (average: 0.6 pg WHO₉₈-TEQ/g sample (1.243 pg WHO₉₈-TEQ/g sample) and large marine fish (0.6). In Taiwan, a decreasing trend of PCDD/Fs or dioxin-like PCBs (dl-PCBs) was observed in meat, dairy, eggs, and vegetables, whereas an elevated trend was observed in cereals or the levels were nearly equal in fruits and oils at alternative time shift. Dl-PCBs contributed to 60–65% toxicity equivalence levels in fish and seafood, but only to 13–40% in meat and cereal samples. The decreasing trend was consistent with the results in other countries; however, the trends in cereals, fruits, and oils were in contrast to previous results reported in other countries. Cereals and fruits are important crops in southern Taiwan, and the local pollution generated by industries or incinerators may seriously affect the distribution of PCDD/Fs and dl-PCBs. To ensure food safety, a risk assessment for residents living in different areas should be adopted for all food categories simultaneously in the future.

A Facile and Low-Cost Method to Enhance the Internal Quantum Yield and External Light-Extraction Efficiency for Flexible Light-Emitting Carbon-Dot Films

Solution-processed, non-toxic carbon dots (CDs) have attracted much attention due to their unique photoluminescence (PL) properties. They are promising emissive layers for flexible light-emitting devices. To this end, the CDs in pristine aqueous solutions need to be transferred to form solid-state thin films without sacrificing their original PL characteristics. Unfortunately, solid-state PL quenching induced by extra non-radiative (NR) energy transfer among CDs would significantly hinder their practical applications in optoelectronics. Here, a facile, low-cost and effective method has been utilized to fabricate high-performance CD/polymer light-emitting flexible films with submicron-structured patterns. The patterned polymers can serve as a solid matrix to disperse and passivate CDs, thus achieving high internal quantum yields of 61%. In addition, they can act as an out-coupler to mitigate the waveguide-mode losses, approximately doubling the external light-extraction efficiency. Such CD/polymer composites also exhibit good photo-stability, and thus can be used as eco-friendly, low-cost phosphors for solid-state lighting.

Influenza A plasma and serum virus antibody detection comparison in dogs using blocking enzyme-linked immunosorbent assay

Background and Aim:

The influenza A virus (IAV) is an important zoonotic pathogen with infections also reported in dogs. IAV infections can be detected through the presence of antibodies using the enzyme-linked immunosorbent assay (ELISA). Serum is the only standard sample source; however, there is no information on the availability of other sample sources for IAV antibody detection in dogs. Compared with serum, plasma is more widely employed in most animal hospitals. The object of this study is to investigate whether plasma collected in ethylenediaminetetraacetic acid (EDTA) tubes (EDTA plasma) or heparin tubes (heparin plasma) could be used in the ELISA protocol instead of serum for IAV antibody detection in dogs.

Materials and Methods:

Totally, 82 matched EDTA plasma and serum sample pairs and 79 matched heparin plasma and serum sample pairs were employed using blocking enzyme-linked immunosorbent assay (bELISA). The agreement and correlation between the plasma (EDTA or heparin plasma) and serum were assessed using the agreement index kappa (kD) calculation and Pearson correlation coefficient, respectively.

Results:

The agreement index kD of EDTA plasma and serum was 1.0, and that of heparin plasma and serum was 0.85. The Pearson correlation coefficient of EDTA plasma and serum was 0.87 (p<0.01), and that of heparin plasma and serum was 0.82 (p<0.01).

Conclusion:

The results proved that plasma, especially EDTA plasma, could be substituted for serum in the bELISA test. This might greatly expand the clinical applicability of IAV antibody detection in dogs.

Repeated Dose 90-Day Feeding Study of Whole Fruits of Genetically Modified Papaya Resistant to Papaya Ringspot Virus in Rats

Genetically modified (GM) papaya plants resistant to infection by Papaya ringspot virus (PRSV) have been successfully generated by cloning the coat protein (CP) gene of PRSV to increase fruit production. In this study, the GM papaya line 823-2210 was used to conduct a 90-day feeding toxicity study and compared to its parent plant of non-GM papaya, Tainung-2 (TN-2) based on the experimental guidance reported by the European Food Safety Authority.1 Ten male and 10 female Sprague-Dawley albino rats were gavaged at low (1 g/kg bw) and high (2 g/kg bw) doses of non-GM and GM lyophilized papaya fruits for 90 days. Hematology, coagulation, biochemistry, urinalysis, and pathology were examined in all animals. Although some differences were found in feed consumption, hematology, and serum chemistry examinations between non-GM and GM papaya, the results were within historical control values and not considered biologically significant in rats. In addition, there were no treatment-related gross or microscopic lesions in male or female rats attributable to the non-GM or GM papaya fruit. This 90-day feeding study of GM papaya fruit did not reveal adverse effects in rats and indicates that GM papaya fruits may be substantially equivalent to their non-GM parent plants.

Toxicity assessment of transgenic papaya ringspot virus of 823-2210 line papaya fruits

The transgenic papaya is a valuable strategy for creating plants resistant to papaya ringspot virus (PRSV) infection and increasing production. This study was further performed to evaluate the comparative toxicity effects of the newly developed transgenic line of the fruits of two backcross transgenic papaya lines (2210 and 823) and one hybrid line (823-2210) and compare to their parent non-transgenic (TN-2) counterparts. The stability analysis of coat protein (CP) of PRSV was investigated using the digestion stability assays in simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and bile salts to detect the CP fragments. Results revealed that the CP fragments were rapidly hydrolyzed in SGF and were undetectable in organs and gastrointestinal contents in rats. For the genotoxicity, three in vitro assays were conducted and exhibited that non-transgenic and backcross transgenic papaya fruits were negative. Moreover, a repeated animal feeding study was conducted by feeding 2 g/kg of body weight (bw) of non-transgenic and backcross transgenic papaya fruits for 28 days in rats. There were no biological or toxicological significances between non-transgenic and backcross transgenic papaya fruits in rats. The results demonstrated that the backcross transgenic papaya fruit can be recognized as an equivalent substitution for traditional papaya in food safety.

Pitfalls of CT for deep neck abscess imaging assessment: a retrospective review of 162 cases

OBJECTIVES

To investigate the diagnostic value of contrast-enhanced computed tomography (CT) for the prediction of deep neck abscesses in different deep neck spaces and to evaluate the false-positive results.

METHOD

We retrospectively analysed the clinical charts, CT examinations, surgical findings, bacteriology, pathological examinations and complications of hospitalised patients with a diagnosis of deep neck abscess from 2004 to 2010. The positive predictive values (PPV) for the prediction of abscesses by CT scan in different deep neck spaces were calculated individually on the basis of surgical findings.

RESULTS

A total of 162 patients were included in this study. All patients received both intravenous antibiotics and surgical drainage. The parapharyngeal space was the most commonly involved space. The overall PPV for the prediction of deep neck abscess with contrast-enhanced CT was 79.6%. The PPV was 91.3% when more than one deep neck space was involved but only 50.0% in patients with isolated retropharyngeal abscesses. In the false-positive group, cellulitis was the most common final result, followed by cystic degeneration of cervical metastases. Five specimens taken intra-operatively revealed malignancy and four of these were not infected.

CONCLUSIONS

There are some limitations affecting the differentiation of abscesses and cellulitis, particularly in the retropharyngeal space. A central necrotic cervical metastatic lymph node may sometimes also mimic a simple pyogenic deep neck abscess on both clinical pictures and CT images. Routine biopsy of the tissue must be performed during surgical drainage.

Influence of dietary supplementation with Bacillus-fermented adlay on lipid metabolism, antioxidant status and intestinal microflora in hamsters

BACKGROUND

The effects of polished and dehulled Bacillus-fermented adlay on lipid metabolism, antioxidant status and intestinal microflora were examined in hyperlipidaemic hamsters fed a high-cholesterol diet.

RESULTS

Hamsters administered Bacillus-fermented adlay experienced significantly reduced (P < 0.05) serum and hepatic total cholesterol (by 37-43% and 42-49% respectively) and triglyceride (by 22-27% and 30-35% respectively) levels compared with the high-cholesterol group. Lower low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratios in serum and increased cholesterol (by 47-52%) and triglyceride (by 40-47%) contents in faeces were also observed. Bacillus-fermented adlay lowered the levels of thiobarbituric acid-reactive substances, thus increasing total antioxidant and superoxide dismutase activities. In particular, polished Bacillus-fermented adlay had satisfactory antioxidant activity, similar to that of commercially available natto. Moreover, hamsters fed Bacillus-fermented adlay harboured greater populations of lactic acid bacteria, few coliforms and little Clostridium perfringens.

CONCLUSION

This study has shown that changes in lipid metabolism, antioxidant status and intestinal microflora can be greatly modulated by Bacillus-fermented adlay, suggesting potential novel approaches to the treatment of primary cardiovascular and intestinal diseases.

Use of murine models to detect the allergenicity of genetically modified Lactococcus lactis NZ9000/pNZPNK

By introducing aprN into Lactococcus lactis NZ9000, the genetically modified L. lactis NZ9000/pNZPNK successfully expressed the nattokinase. The safety assessment of this novel strain was based on allergenicity of pepsin digestion stability and murine model serologic identity. Subjecting to the GM strain and host to pepsin digestion, the soluble fractions and cell debris were fast degraded completely. Feeding with ovalbumin resulted in significantly higher production of IgG1 and IgE as compared to that of L. lactis NZ9000/pNZPNK or L. lactis NZ9000. Further, the serum IgG2a level increased dose-dependently at week 2 and induced immune reaction toward Th1 pathway. Secretion of cytokines IL-4 and IL-10 fed with lactococci was significantly lower than that of the OVA group. L. lactis NZ9000/pNZPNK did not increase the proliferation of type 2 helper T cells in spleen or induce allergenicity in BALB/c mice. On the basis of the results, the new GM lactic acid bacterium is regarded as safe to use.

Energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding

We present the first observation of resonance energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding. Steady-state and time-resolved photoluminescence measurements provide conclusive evidence of resonance energy transfer and obtain an optimum transfer efficiency of ~72%. A set of rate equations is successfully used to model the kinetics of resonance energy transfer.

Orally administered mycelial culture of Phellinus linteus exhibits antitumor effects in hepatoma cell-bearing mice

AIM OF THE STUDY

The aim of this study was to evaluate the anticancer effect of a mycelial culture from Phellinus linteus PL-7 (MCPL-7) and to elucidate its potential mechanism in vivo.

MATERIALS AND METHODS

SCID CB-17 mice received a transplant of Hep3B cells followed by daily MCPL-7 administrations for 8 weeks. Following tumor implantation, groups C-E were subcutaneously administered 50 mg/kg, 100 mg/kg, or 250 mg/kg MCPL-7 powder per day, respectively, for 8 weeks. Groups A and B received saline solution subcutaneously for 8 weeks.

RESULTS

MCPL-7 administration induced a significant reduction in tumor size and was associated with a significant increase in T cell numbers; IL-12, IFN-γ and TNF-α secretion; NK cell activity; and phagocytic ability. Therefore, increased numbers of CD4(+) cells could have been caused by greater numbers of dendritic cells and macrophages in the spleen. Furthermore, the activation of dendritic cells and macrophages resulted in increased IL-12 secretion, which could upregulate NK cell activation. The increased secretion of IL-12, IFN-γ, and TNF-α enhanced the activity and phagocytic ability of NK cells. Thus, MCPL-7 may provide a potential therapeutic approach for both immunomodulatory and antitumor effects.

Allergenicity assessment of genetically modified cucumber mosaic virus (CMV) resistant tomato (Solanum lycopersicon)

Cucumber mosaic virus (CMV) has been identified as the causal agent of several disease epidemics in most countries of the world. Insect-mediated virus diseases, such as those caused by CMV, caused remarkable loss of tomato (Solanum lycopersicon) production in Taiwan. With expression of the CMV coat protein gene (Cmvcp) in a local popular tomato cultivar L4783, transgenic tomato line R8 has showed consistent CMV resistance through T(0) to T(8). In this report, the allergenicity of the CMV coat protein (CMV cp) expressed in transgenic tomato R8 was assessed by investigation of the expression of the transgene source of protein, sequence similarity with known allergens, and resistance to pepsin hydrolysis. There is no known account for either the CMV or its coat protein being an allergen. The result of a bioinformatic search also showed no significant homology between CMV cp and any known allergen. The pepsin-susceptible property of recombinant CMV cp was revealed by a simulated gastric fluid (SGF) assay. Following the most recent FAO/WHO decision tree, all results have indicated that CMV cp was a protein with low possibility to be an allergen and the transgenic tomato R8 should be considered as safe as its host.

Artificial neural network analysis for reliability prediction of regional runoff utilization

Many factors in the reliability analysis of planning the regional rainwater utilization tank capacity need to be considered. Based on the historical daily rainfall data, the following four analyzing procedures will be conducted: the regional daily rainfall frequency, the amount of runoff, the water continuity, and the reliability. Thereafter, the suggested designed storage capacity can be obtained according to the conditions with the demand and supply reliability. By using the output data, two different types of artificial neural network models are used to build up small area rainfall-runoff supply systems for the simulation of reliability and the prediction model. They are also used for the testing of stability and learning speed assessment. Based on the result of this research, the radial basis function neural network (RBFNN) model, using the Gaussian function that has a similar trend as the nature as basic function, has better stability than using the back-propagation neural network (BPNN) model. Despite the fact that RBFNN was more reliable than BPNN, it still made a conservative estimate for the actual monitoring data. The error rate of RBFNN was still higher than the correction of BPNN 4-3-1-1. This should have significant benefit in the future application of the instantaneous prediction or the development of related intelligent instantaneous control equipment.

Anticancer effects of flavonoid derivatives isolated from Millettia reticulata Benth in SK-Hep-1 human hepatocellular carcinoma cells

Millettia reticulata Benth is cultivated in Asian countries. M. reticulata Benth has multiple biological functions and is one of the oldest tonic herbs in traditional Chinese medicine. It has been elevated to one of the most commonly used herbs in modern Chinese medicine. The aims of this work were to study the in vitro anticancer activity of flavonoid derivatives isolated from the stems of M. reticulata Benth. Six flavonoid derivatives including (-)-epicatechin (1), naringenin (2), 5,7,3',5'-tetrahydroxyflavanone (3), formononetin (4), isoliquiritigenin (5), and genistein (6) were isolated from the stems of M. reticulata Benth. The structures of 1-6 were determined by spectroscopic methods. The effects of flavonoid derivatives (1-6) on the viability of human cancer cells (including HepG2, SK-Hep-1, Huh7, PLC5, COLO 205, HT-29, and SW 872 cells) were investigated. The results indicated that genistein (6) had the strongest inhibitory activity with an IC(50) value of 16.23 microM in SK-Hep-1 human hepatocellular carcinoma cells. Treatment of SK-Hep-1 cells with genistein (6) caused loss of mitochondrial membrane potential. Western blot data revealed that genistein (6) stimulated an increase in the protein expression of Fas, FasL, and p53. Additionally, treatment with genistein (6) changed the ratio of expression levels of pro- and anti-apoptotic Bcl-2 family members and subsequently induced the activation of caspase-9 and caspase-3, which was followed by cleavage of poly(ADP-ribose) polymerase (PARP). These results demonstrate that genistein (6) induces apoptosis in SK-Hep-1 cells via both Fas- and mitochondria-mediated pathways.

Safety assessment and detection method of genetically modified Chinese Kale (Brassica oleracea cv. alboglabra )

Sporamins are tuberous storage proteins and account for 80% of soluble protein in sweet potato tubers with trypsin-inhibitory activity. The expression of sporamin protein in transgenic Chinese kale (line BoA 3-1) conferred insecticidal activity toward corn earworm [ Helicoverpa armigera (Hubner)] in a previous report. In this study, we present a preliminary safety assessment of transgenic Chinese kale BoA 3-1. Bioinformatic and simulated gastric fluid (SGF) analyses were performed to evaluate the allergenicity of sporamin protein. The substantial equivalence between transgenic Chinese kale and its wild-type host has been demonstrated by the comparison of important constituents. A reliable real-time polymerase chain reaction (PCR) detection method was also developed to control sample quality. Despite the results of most evaluations in this study being negative, the safety of sporamin in transgenic Chinese kale BoA 3-1 was uncluded because of the allergenic risk revealed by bioinformatic analysis.

Thermal modeling and performance analysis of a thermoacoustic refrigerator

A heat-driven thermoacoustic refrigerator has been designed and tested. A detailed thermal model of the device is presented. Energy balances within the system are discussed using external, heat exchanger, and stack control volumes in order to clarify the relationships of work and heat fluxes below and above onset. Thermal modeling is discussed as a tool for performance analysis as well as for determining system heat losses and finding input heat flows required by a thermoacoustic code. A method of using the control volume balance equations to find stack work and device efficiencies is presented. Experimental measurements are compared to DELTAE thermoacoustic modeling predictions. Modeling results show that viscous losses within the system have a significant impact on the device performance as well as on the ability of DELTAE to accurately predict performance. Modeling has led to an understanding of system performance and highlighted loss sources that are areas for improvement in a redesign.

Dissipation of epoxiconazole in the paddy field under subtropical conditions of Taiwan

The environmental fate and distribution of fungicide epoxiconazole were studied by a rice paddy field model ecosystem. One week before the head-sprouting stage, rice plant was treated separately once with OPUS (tradename of epoxiconazole) 12% SC 2.1 kg ha(-1) and 1.4 kg ha(-1), respectively. Soil, water and rice plant were sampled seven days intervals nine times after application. The bioconcentration factor of epoxiconazole on mosquito fish in the ecosystem was also determined, based on the amounts of epoxiconazole content both in fish and water. This was initiated one day after the fungicide treatment, and continued for four days. In addition, the residue of epoxiconazole in rice grains was analyzed after harvest. After harvest, both planted water spinach (Ipomoea aquatica Forsk) and edible amaranth (Amaranthus mangostanüs L.) were analyzed. The results showed that epoxiconazole degraded in the local environment under the experimental conditions described. The degradation equations were in accordance with the first order kinetics. The DT50 of soil, field water and rice plant were 20-69 days, 11-20 days and 14-39 days, respectively. The bioconcentration factors of epoxiconazole on mosquito fish were 12.9 and 10.6 from 2.1 kg ha(-1) and 1.4 kg ha(-1) treatment, respectively. Residues of epoxiconazole in both rice and harvest vegetables were non-detectable. This indicates that epoxiconazole applied to rice at the recommended rates and application frequencies will not accumulate on rice grain and successive cropping vegetables.

Hantavirus infection in Taiwan: the experience of a geographically unique area

Hantaviruses are rodent-borne viruses, and they, mainly the Hantaan (HTN) serotype, are the causative agents of a group of febrile nephropathies known as "hemorrhagic fever with renal syndrome (HFRS). " Despite the fact that HFRS is frequently reported in China, with an annual incidence of 50,000-100,000 cases, one puzzling observation that no local case of HFRS has been confirmed in Taiwan has yet to be explained. We hypothesized that the hantavirus strain prevailing in Taiwan mainly belongs to the mild strain, the Seoul (SEO) strain, and the absence of severe disease was related to the absence of HTN. To test these hypotheses, this epidemiologic study was performed, including a seroprevalence survey and phylogenetic analysis on hantavirus isolated from the rodent population trapped in major seaports, rural, and mountainous areas of Taiwan. This study also included rodents and viruses from two isolated islands, Kinmen and Matzu, which are geographically adjacent to the east coast of mainland China. There were a total of 5,461 rodents of 16 species captured, and R. norvegicus was the most common species, with an antibody prevalence much higher in international seaports (20%) than in rural regions (approximately 5%) and intermediate in some domestic seaports. By reverse transcriptase polymerase chain reaction (RT-PCR), 33.9% of the seropositive R. norvegicus were found to have amplifiable hantavirus sequences in their lung tissues, and subsequent phylogenetic analyses indicated that almost all hantavirus in Taiwan was most closely related to the prototype SEO strain, and no HTN strain was recovered from any rodent species indigenous to Taiwan. The seroprevalence of SEO infection in R. norvegicus on Kinmen and Matzu was also different from that in southern provinces of China but closely resembled that in seaports in Taiwan, and the SEO identified was genetically linked to Taiwanese SEO strains. These results substantiate our hypotheses, and suggest that the epidemiology of hantavirus infection in Taiwan are different from that in China, where the HTN and SEO strains and HFRS concurrently prevail.

Changes in volatile flavor components of guava juice with high-pressure treatment and heat processing and during storage

The changes in volatile flavor components of guava juice during pressure processing (25 degrees C, 600 MPa, 15 min), heat processing (95 degrees C, 5 min), and storage at 4 and 25 degrees C were evaluated by purge and trap/gas chromatography/mass spectrometry. Esters were the major volatile fraction in guava juice, and alcohols were the second. Pressure processing could maintain the original flavor distribution of the juice. Heat processing (95 degrees C, 5 min) caused decreases in the majority of flavor components in the juice when compared with freshly extracted juice. High-pressure treatment at 600 MPa for 15 min can effectively sterilize microbes but partially inactivate enzymes of guava juice; therefore, volatile components in pressure-treated juice gradually changed during storage periods. Pressure-treated guava juice showed increases in methanol, ethanol, and 2-ethylfuran with decreases in the other components during storage period. Nevertheless, the volatile distribution of 600 MPa treated guava juice was similar to that of freshly extracted juice when stored at 4 degrees C for 30 days.

High pressure and heat treatments effects on pectic substances in guava juice

Effects of high pressure treatment on changes in pectic substances in guava juice were investigated and compared with those of heat treated samples. The viscosity and turbidity of guava juice pressurized at 6000 atm and 25 degrees C for 10 min increased slightly, whereas the viscosity of juice heated at 95 degrees C for 5 min decreased from 362 to 285 cps while turbidity increased from 0.87 to 1.15 (OD 600 nm). There were no apparent changes in water soluble, oxalate soluble and alkali soluble pectins in the pressurized juice. However, heat treated juice exhibited a decrease in its water and alkali soluble pectins and a slight increase in oxalate soluble pectin. The DEAE-cellulose profiles of pectic substances in guava juice were apparently unchanged after high pressure treatment while they were markedly changed by heat treatment, due to coagulation or degradation. During thermal processing, the degradation of pectin in guava juice caused a decrease in viscosity while the coagulation of pectin resulted in an increase in turbidity and cloud content. High pressure treatment showed no marked changes in pectic substances and cloud content in guava juice and maintained its natural viscous properties.

Quantitative analysis of mRNA encoding MUC1, MUC2, and MUC5AC genes: a correlation between specific mucin gene expression and sialomucin expression in non-small cell lung cancer

The expression of mucins is important for tumor invasiveness and metastasis. In our previous report (Am. J. Respir. Crit. Care Med. 1997; 155:1419-1427), non-small cell lung cancers bearing sialomucin expression tended to relapse earlier than those without sialomucin. However, it remained unclear whether the expression of sialomucin in lung cancer is caused by an abnormal glycosylation process or by the expression of a specific mucin gene product. To address this problem, we established a modified quantitative competitive polymerase chain reaction (QC-PCR) analysis. RNA internal standards of MUC1, MUC2, and MUC5AC non-tandem repeat sequences were constructed, and known copy numbers of mucin RNA internal standards were introduced into reverse transcription-polymerase chain reactions (RT-PCR) for each mucin gene in order to compete with native mucin gene RNA during the reaction. The RNA of Gbeta-like gene (a housekeeping gene) was used as internal control for the RNA analysis. Twenty-five lung cancer tissues (13 adenocarcinomas and 12 squamous cell carcinomas) were used for analysis. Mann-Whitney rank sum test was applied to compare the expression amounts of different mucin genes in tissues. The results revealed that adenocarcinoma expressed higher amounts of MUC5AC gene than did squamous cell carcinoma (P = 0.03). The expression amount of MUC5AC correlated positively with the expression status of sialomucin (P = 0.012). Further studies are anticipated to elucidate the underlying mechanism contributing to this phenomenon.

99Tcm-HMPAO-labelled white blood cell scans to detect acute appendicitis in older patients with an atypical clinical presentation

Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0%, 91.7%, 91.8%, 92.0% and 91.7% respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.

Tc-99m HMPAO-labeled WBC scans to detect appendicitis in women

Fifty female patients with acute abdomen and suspected appendicitis but atypical findings were included in this study. After intravenous injection of Tc-99m HMPAO-labeled WBCs, serial anterior abdominal/pelvic images at 30, 60, 120, and 240 minutes were obtained by a gamma camera. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen with equal to or greater than bone marrow activity was considered as a positive scan. Thirty patients had positive WBC scans and underwent laparotomy, 28 had proven appendicitis, and 2 were not related to appendicitis. Twenty patients had negative WBC scans, 2 patients underwent laparotomy and were proved to have appendicitis. The remaining 18 patients did not undergo surgery and revealed no evidence of appendicitis after follow-up. The overall sensitivity, specificity, accuracy, and positive and negative predictive values for WBC scans to diagnose appendicitis is 93.3%, 90.0%, 92.0%, 93.3%, and 90.0%, respectively. In conclusion, Tc-99m HMPAO-labeled WBC imaging provides a rapid and highly accurate method for diagnosis of appendicitis in female patients with equivocal clinical examinations.

Supine lung clearance of Tc-99m DTPA and HMPAO aerosols

The speed of Tc-99m DTPA/HMPAO radioaerosol clearance from the lungs that is represented as a slope from lungs to blood was measured in 23 male normal controls using commercial lung radioaerosol delivery units in the supine position in order to avoid the influences of gravity. The right lung was selected and three regions of interest were created for equal subdivisions of the upper, middle, and lower third. The results show that the clearance of Tc-99m DTPA/HMPAO aerosols in the upper lung is slowest. The differences between upper and lower lungs for Tc-99m DTPA/HMPAO aerosol clearances are significant. The clearance of Tc-99m DTPA aerosols was significantly faster than those of Tc-99m HMPAO in any region. The authors conclude that, although the effect of gravity disappears in the supine position in our study, the differences of aerosol clearance in different regions are still significant. Lipophilic Tc-99m HMPAO aerosols were slower than those of hydrophilic Tc-99m DTPA, which suggests there are at least two different mechanisms.

Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Alveolar integrity in pulmonary emphysema using technetium-99m-DTPA and technetium-99m-HMPAO radioaerosol inhalation lung scintigraphy

The alveolar integrity (AI) in 17 male patients with pulmonary emphysema (EMPH) diagnosed by chest x-ray was measured by 99mTc-DTPA and 99mTc-HMPAO radioaerosol inhalation lung scintigraphy.

METHODS

The patients were divided into two groups: (A) nine patients with pulmonary emphysema and normal carbon monoxide diffusion capacity (DLCO) and (B) eight patients with pulmonary emphysema and abnormal DLCO. The degree of AI damage in EMPH was presented as the slope of the time-activity curves from the dynamic left lung imagings in DTPA and HMPAO. The AI of EMPH patients were compared with the AI of 16 normal controls.

RESULTS

The results show that: (1) the slope of DTPA is larger than that of HMPAO in each of the portions of the left lung for any of the study groups; (2) statistical differences were found between the normal controls and EMPH patients in HMPAO but not in DTPA; and (3) the correlation was not good between DLCO and DTPA/HMPAO in EMPH patients.

CONCLUSION

Our results suggest that: (1) at least two different mechanisms in the lungs were at work; (2) the AI damage in EMPH developed mainly in the lipophilic part of the alveoli; and (3) the AI damage presented as slopes of DTPA/HMPAO in our study was different from the traditional pulmonary function such as DLCO.

Lung inflammation in patients with systemic lupus erythematosus detected by quantitative 67Ga-citrate lung scanning

The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.

Relationship of alveolar permeability and lung inflammation in patients with active diffuse infiltrative lung disease detected by 99Tcm-DTPA radioaerosol inhalation lung scintigraphy and quantitative 67Ga lung scans

The alveolar permeability (AP) in 21 patients with active diffuse infiltrative lung disease (ILD) was measured by 99Tcm-diethylenetriaminapentaacetate (DTPA) radioaerosol inhalation lung scintigraphy. The degree of AP damage in ILD was presented as the slope (% min-1) of the time-activity curve from the dynamic lung image. Meanwhile, the quantitative Ga lung scan (GA) was performed as a Ga uptake index (GUI) to evaluate the severity of lung inflammation in active ILD. The results show that no good correlation between the degree of AP damage and lung inflammation was found. When the patients were divided into two groups of (A) eight active ILD with normal chest X-ray (X-ray) and (B) 13 active ILD with abnormal X-ray, there was no significant difference between groups A and B for the DTPA and Ga results. In conclusion, the relationship between the degree of AP damage and lung inflammation in active ILD is not significant. This was not consistent with X-ray findings. There was, however, a significant difference between those with ILD and normal controls.

Influences of noise on the occurrence of period doubling in distributed-feedback laser diodes under direct-current modulation

The influences of Langevin noise on period doubling (PD) of a strongly modulated distributed-feedback laser have been investigated. The onset of PD was confirmed to be reduced through the use of the rate equations as a model. The threshold values of PD were examined in terms of driving frequency and rf power and have been compared with the measurements of PD.

[The management of sinus tracts of dental origin]

The purpose of this study was to evaluate the results of conservative endodontic therapy of 86 fistulous cases of dental origin at the Department of Conservative Dentistry, Kaohsiung Medical College Hospital. Approximately 60% (52/86) endodontically treated teeth, with a minimum recall period of 6 months, were evaluated for success or failure. The results are as follows: (1) The overall success rate was 82.7% (43/52) fistulous cases. There was no significant statistical difference between male and female patients. (2) There was a better success rate with cases over a 2-year recall period than with cases under a 2-year recall period, but there was no significant statistical difference between these two groups. (3) Cases with periapical pathosis less than 5 mm in diameter, had a better success rate than those with periapical pathosis larger than 5 mm in diameter, but there was no significant statistical difference between these two groups. (4) There was a 79.1% (34/43) success rate in non-surgically treated cases, and a 66.7% success rate (6/9, excluding three successfully retreated cases which had been originally treated with a non-surgical technique) in surgically treated cases.

[Sinus tracts of dental origin. A clinical study. Part I]

Chronic draining sinus tracts on the oral mucosa or the skin of the face frequently have dental pathosis. The purpose of this study was to investigate the incidence and the distribution of age, sex, opening, and tooth position of sinus tract cases with dental origin. A total of 678 teeth requiring endodontic treatment and having periapical pathosis at the Department of Conservative Dentistry, Kaohsiung Medical College Hospital, were studied. There were 86 (12.7%) teeth associated with sinus tracts, among these 47 (16.3%, 47/288) were from males and 39 (10.0%, 39/390) were from females. Of the openings of the sinus tracts, 70 were on the facial, 2 were on the palatal, 1 was on the distal, 4 were on the lingual, 2 were on both facial and lingual surfaces of teeth, and 7 were extraorally. The sinus tracts occurred more frequently in the mandibular than maxillary teeth. The maximum number of 34 cases (39.5%, 34/86) were from the 21-30 years of age group. In addition, we also found that the teeth with periapical lesions of larger than 5 mm in diameter are more frequently associated with sinus tracts than those teeth with lesions of smaller than 5 mm in diameter.