[Effects of salivary microbiota on tryptophan-aryl hydrocarbon receptor signaling axis in mice with periodontitis]

Objective: To study the effects of salivary microbiota in patients with periodontitis on the tryptophan-aryl hydrocarbon receptor (AhR) signaling axis in mice with periodontitis and to provide theoretical basis as well as new ideas for the influences of periodontitis on systemic metabolism. Methods: Salivary microbiota of 12 healthy individuals and 14 patients with periodontitis were collected in Nanjing Stomatological Hospital, Medical School of Nanjing University from June to December of 2020. According to the random number table method, twenty-four mice were randomly divided into three groups: Sham group (control group), P group (periodontitis patients' salivary microbiota group) and H group (periodontal healthy individuals' salivary microbiota group). The maxillary second molars of all mice were treated with silk thread ligation to induce periodontitis. Phosphate buffer as well as salivary microbiota of periodontal healthy individuals and periodontitis patients were gavaged into periodontitis mice for 2 weeks. The expression of inflammatory factors in mice serum were detected by enzyme linked immunosorbent assay, and the expression of tryptophan and indole metabolites in intestinal tract and serum were detected by liquid chromatography-mass spectrometry. The expression of AhR in intestinal tract of mice was detected by immunohistochemistry and quantitative real time-PCR while gut microbiota constitution was detected by 16S rRNA gene sequencing. The remaining saliva samples of periodontitis patients and periodontal healthy individuals were applied to detect the expression of tryptophan and indole metabolites themselves. Results: The salivary microbiota of periodontitis patients could induce the expression of interleukin-1β [P group: (162.38±39.46) pg/ml, H group: (82.83±20.01) pg/ml; t=4.40, P=0.001) and tumor necrosis factor-α [P group: (361.16±123.90) pg/ml, H group: (191.66±106.87) pg/ml; t=2.54, P=0.030) in serum of periodontitis mice, and reduce the expression of AhR in colon (P group: 1.18±0.05, H group:1.83±0.47; t=3.09, P=0.015) and ileum (P group: 0.80±0.13, H group: 1.18±0.11; t=4.93, P=0.001). After gavage of salivary microbiota of periodontitis patients to the mice, tryptophan (P group: (18.1±3.8)×10⁷, H group: (26.6±6.6)×10⁷; t=2.49, P=0.037] and indole lactic acid [P group: (1.9±0.7)×10⁷, H group: (3.7±0.6)×10⁷; t=4.49, P=0.002) in serum of periodontitis mice were significantly decreased, but was relatively disorder in intestinal tract. However, the expressions of tryptophan and indole metabolites in saliva of periodontitis patients were higher than those of periodontal healthy individuals. There were significant differences in indole propionic acid [P group: (1 239.39±818.72) nmol/L, H group: (56.96±38.33) nmol/L; t=2.83, P=0.022]. What we find noteworthy was that the expressions of indolelactic acid metabolism in saliva, serum and intestinal were consistent, and salivary microbiota of periodontitis patients could reduce the relative abundance of indolelactic acid-producing bacteria in the gut, suggesting that the salivary microbiota of periodontitis patients might affect the expression of AhR through gut microbiota disorder and indolelactic acid downregulation. Conclusions: Salivary microbiota in patients with periodontitis may affect the systemic inflammatory state through down-regulating the expression of tryptophan-AhR signal axis.

[Current status and research progress of third-line treatment for patients with gastric cancer in China]

Gastric cancer (GC) is one of the most common malignant tumors in the world. The prognosis of advanced GC is extremely poor, characterized by the high recurrence or disease progression rate after the first-line chemotherapy, and the extremely low long-term survival rate. Meanwhile, the options for subsequent treatment are limited. Studies have shown that the third-line therapy can provide significant survival benefits for selected patients with advanced GC. Currently, a series of randomized controlled trials and real-world studies related to chemotherapy, targeted therapy, and immunotherapy are conducted. In addition, the explorations of combination therapy, and screening the optimal clinical features or predictive biomarkers for the suitable population who might benefit from the third-line regimens are the hot spots for researchers. This article will provide a detailed overview of the current status and progress of the third-line treatment for advanced GC, and to illustrate the characteristics of Chinese GC treatment.

Perioperative outcomes of women with and without class III obesity undergoing hysterectomy for endometrioid endometrial cancer: A population-based study

OBJECTIVE

Population-based data on perioperative complications among women with endometrial cancer and severe obesity are lacking. We evaluated 30-day complication rates among women with and without class III obesity (body mass index ≥ 40 kg/m²) undergoing primary surgical management for endometrioid endometrial cancer (EEC), and how outcomes differed according to surgical approach (open vs. minimally invasive).

METHODS

We performed a retrospective population-based cohort study of women with EEC undergoing hysterectomy in Ontario, Canada, between 2006 and 2015. We evaluated perioperative complications in the whole cohort, and in a 1:1 matched analysis using hard and propensity score matching to ensure similar distributions of patient, tumour, provider and institution-level factors between women with and without class III obesity (identified using a surgical billing code). The primary outcome of interest was the 30-day perioperative complication rate.

RESULTS

12,112 women met inclusion criteria; 2697 (22.3%) had class III obesity. We matched 2320 (86%) women with class III obesity to those without. The composite complication rate was significantly higher among women with class III obesity (23.2% vs. 18.4%, standardized mean difference [SMD] = 0.12), primarily due to wound infection/disruption (12.1% vs. 6.2%). There was no difference in outcomes for women with and without class III obesity when a minimally invasive approach was used.

CONCLUSIONS

Wound infection/disruption was increased for women with class III obesity compared to women without. Otherwise, perioperative complications were similar between the matched pairs. When minimally invasive approaches were used, women with class III obesity had a similar risk of complications as women without obesity.

Temperature and excitation wavelength dependence of circular and linear photogalvanic effect in a three dimensional topological insulator Bi2Se3

The circular (CPGE) and linear photogalvanic effect (LPGE) of a three-dimensional topological insulator Bi₂Se₃ thin film of seven quintuple layers excited by near-infrared (1064 nm) and mid-infrared (10.6 [Formula: see text]m) radiations have been investigated. The comparison of the CPGE current measured parallel and perpendicular to the incident plane, together with the comparison of the CPGE current under front and back illuminations, indicates that the CPGE under front illumination of 1064 nm light is dominated by the top surface states of the Bi₂Se₃ thin film. The CPGE current excited by 10.6 [Formula: see text]m light is about one order larger than that excited by 1064 nm light, which may be attributed to the smaller cancelation effect of the CPGE generated in the two-dimensional electron gas when excited by 10.6 [Formula: see text]m light. Under the excitation of 1064 nm light, the LPGE current is dominated by the component which shows an even parity of incident angles, while the LPGE current excited by 10.6 [Formula: see text]m light is mainly contributed by the component which is an odd parity of incident angles. Both of the CPGE and LPGE currents excited by 1064 nm decrease with increasing temperature, which may be owing to the decrease of the momentum relaxation time and the stronger electron-electron scattering with increasing temperature, respectively.

The generation of two specific cancer costing algorithms using Ontario administrative databases

Cancer treatment and management have become increasingly economically burdensome. Consequently, to help with planning health service delivery, it is vital to understand the associated costs. Administrative databases can be used to help understand and generate real-world system-level costs. Using databases to generate costs can take one of two approaches: top-down or bottom-up. Top-down approaches disaggregate the total health care spending from a global health care budget by sector and provider. A bottom-up approach begins with individual-level health care use and its costs, which are then aggregated.

Effects of an Oral-Pharyngeal Motor Training Programme on Children with Obstructive Sleep Apnea Syndrome in Hong Kong: A Retrospective Pilot Study

Background

This study aimed to investigate the effects of an oropharyngeal motor training programme on children with Obstructive Sleep Apnea Syndrome (OSAS) in Hong Kong.

Methods

In this retrospective study, we reviewed the outcomes of 10 children with OSAS who had received an oropharyngeal motor training programme in Occupational Therapy Department of an acute hospital in Hong Kong over a 1-year programme. Each participant attended an individual oropharyngeal motor training programme plus a follow-up session after 2 months. The training programme consisted of 10 individual mobilization exercises involving the orofacial and pharyngeal area for 45 minutes. Each exercise had to be repeated for 10 times. Three outcome measures were chosen to study the effectiveness of the training programme including tongue strength, tongue endurance level and orofacial function. Tongue strength and tongue endurance level were assessed using the Iowa Oral Pressure Instrument (IOPI). The Nordic Orofacial Test-Screening (NOT-S) Assessment was used to assess the orofacial function. Seven out of 10 participants completed the training programme and attended the follow-up session after two months.

Results

The tongue strength and the scores of NOT-S of the 7 participants were found to have significant improvement after training. However, there was no significant difference in tongue endurance level.

Conclusion

The findings of this study support the role of occupational therapist in oromotor training modalities to improve the respiratory function for children with OSAS in Hong Kong. Copyright © 2017, Hong Kong Occupational Therapy Association. Published by Elsevier (Singapore) Pte Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

[Clinical value of T-cell interferon releases detection of tuberculosis infection assay in quick diagnosis of spinal tuberculosis]

OBJECTIVE

To evaluate the value of T-cell interferon releases detection of tuberculosis infection(T-SPOT.TB)assay in quick diagnosis of spinal tuberculosis.

METHODS

From January 2012 to June 2015, a group of 122 diagnosed patients with spinal tuberculosis in the Qingdao Municipal Chest Hospital and a group of 86 patients suspected with spinal tuberculosis in Department of Orthopaedic, the Qingdao Third People's Hospital were accepted to undergone TB-DOT, T-SPOT.TB and TB-DNA PCR tests Department of Clinical Laboratory.

RESULTS

The sensitivity of TB-DOT, T-SPOT.TB and TB-DNA PCR tests were 69.7%, 86.1% and 56.6%, respectively.The sensitivity of T-SPOT.TB was significantly higher than TB-DOT and TB-DNA PCR tests (χ(2)=9.51, P<0.05; χ(2)=25.96, P<0.05). The specificity of TB-DOT, T-SPOT.TB and TB-DNA PCR tests were 62.8%, 88.3% and 91.9%, respectively.The specificity of T-SPOT.TB was significantly higher than TB-DOT test (χ(2)=15.25, P<0.05).

CONCLUSIONS

T-SPOT.TB assay possesses high sensitivity and specificity in quick diagnosis of patients with spinal tuberculosis, which is valuable in diagnosis of spinal tuberculosis.

[Second-line treatment for metastatic or locally advanced gastric cancer]

Gastric cancer is one of the major causes of cancer-related deaths. Many patients with metastatic gastric cancer after first-line chemotherapy received salvage chemotherapy in routine clinical practice. Recent phase Ⅲ trials demonstrated substantial prolongation of overall survival to support this chemotherapy or targeted therapy as a second-line treatment. Both ramucirumab monotherapy and ramucirumab plus paclitaxel were approved by FDA in patients with previously treated advanced gastric or gastroesophageal junction adenocarcinoma. In addition, paclitaxel, irinotecan, or docetaxel monotherapy is also recommended for preferred regimens. This review will summarize chemotherapy or targeted therapy as a second-line treatment in advanced gastric cancer.

Radiation costing methods: a systematic review

OBJECTIVE

Costs for radiation therapy (rt) and the methods used to cost rt are highly diverse across the literature. To date, no study has compared various costing methods in detail. Our objective was to perform a thorough review of the radiation costing literature to identify sources of costs and methods used.

METHODS

A systematic review of Ovid medline, Ovid oldmedline, embase, Ovid HealthStar, and EconLit from 2005 to 23 March 2015 used search terms such as "radiation," "radiotherapy," "neoplasm," "cost," " cost analysis," and "cost benefit analysis" to locate relevant articles. Original papers were reviewed for detailed costing methods. Cost sources and methods were extracted for papers investigating rt modalities, including three-dimensional conformal rt (3D-crt), intensity-modulated rt (imrt), stereotactic body rt (sbrt), and brachytherapy (bt). All costs were translated into 2014 U.S. dollars.

RESULTS

Most of the studies (91%) reported in the 33 articles retrieved provided rt costs from the health system perspective. The cost of rt ranged from US$2,687.87 to US$111,900.60 per treatment for imrt, followed by US$5,583.28 to US$90,055 for 3D-crt, US$10,544.22 to US$78,667.40 for bt, and US$6,520.58 to US$19,602.68 for sbrt. Cost drivers were professional or personnel costs and the cost of rt treatment. Most studies did not address the cost of rt equipment (85%) and institutional or facility costs (66%).

CONCLUSIONS

Costing methods and sources were widely variable across studies, highlighting the need for consistency in the reporting of rt costs. More work to promote comparability and consistency across studies is needed.

Expression Patterns of Three Genes Under Short and Long Term Cold Exposure in Thitarodes pui (Lepidoptera: Hepialidae), A Host of Ophiocordyceps sinensis

　　BACKGROUND: Thitarodes larvae are the host of the caterpillar fungus Ophiocordyceps sinensis. Low temperature is the main environmental limitation for larvae growth.

OBJECTIVE

To better understand the cold adaption process in T. pui larvae, the expression patterns of trehalose-6-phosphate synthase (TpTPS), heat shock protein 70 (TpHSP70), and heat shock protein 90 (TpHSP90) were investigated upon short and long-term exposure to 0°C.

MATERIALS AND METHODS

The 6th instar T. pui larvae were collected in July 2013. TpTPS was firstly sequenced and expression patterns of TpTPS, TpHSP70 and TpHSP90 were investigated using quantitative PCR.

RESULTS

Full-length cDNA of TpTPS was 3,012 bp, with an open reading frame of 2,472 bp and an encoding protein of 823 amino acids. TpTPS up-regulation was induced by cold exposure. TpHSP70 expression is altered by cold exposure, but remained low. TpHSP90 expression was obviously up regulated in long-term cold stimulation.

CONCLUSION

All three genes (TpTPS, TpHSP70 and TpHSP90) have likely contributed to cold tolerance in T. pui larvae, TpTPS and TpHSP90 potentially being more important.

Molecular cloning and characterization of GbMECT and GbMECP gene promoters from Ginkgo biloba

Ginkgolides are key pharmaceutical components in Ginkgo biloba. Using the cDNA sequence of the MECP and MECT genes to design primers, we obtained the promoters of these genes from Ginkgo genomic DNA using the genome walking method. The two promoters were 744 and 982 bp in length, respectively. The cis-elements of the GbMECPs and GbMECT promoters were predicted and analyzed using the plant cis-acting regulatory element database. We found major cis-elements in the sequence of the GbMECT and GbMECPs promoters. The GbMECP promoter contains six TATA boxes and eight CAAT boxes. The GbMECT contains five TATA boxes and seven CAAT boxes. Furthermore, some cis-elements in the promoters of GbMECPs and GbMECT included hormone and light-regulated elements, UB-B-induced elements, and stress-related dehydration-responsive elements. Expression analysis results showed that the MECP gene is mainly involved in responses to CCC (cycocel) and UV-B, and that MECT is mainly involved in responses to wounding treatment. These results also showed that the expression model was consistent with the cis-elements present. During the annual growth cycle, the level of GbMECPs was significantly correlated with terpene lactones accumulation in leaves. A fitted quadratic curve showed the best model for correlating GbMECPs with terpene lactones in leaves. These results will help us to understand the transcriptional regulatory mechanisms involved in key gene expression and ginkgolide accumulation in G. biloba.

Dietary Supplementation of Magnesium Sulfate during Late Gestation and Lactation Affects the Milk Composition and Immunoglobulin Levels in Sows

This experiment was conducted to investigate the effects of dietary supplementation of magnesium sulfate (MgSO₄) during late gestation and lactation on sow and litter performance, fecal moisture, blood biochemistry parameters, immunoglobulin levels and milk composition in sows. Forty-eight sows (Yorkshire×Landrace, 4th to 5th parity) were randomly allocated to 1 of 4 dietary treatments supplemented with 0, 200, 400, or 600 mg/kg MgSO₄ (n = 12). The experiment started on day 90 of gestation and continued through day 21 of lactation. Blood samples were collected on day 107 of gestation, day 0 (farrowing) and 21 (weaning) of lactation for the analyses of the blood biochemistry parameters and immunoglobulin levels. The colostrum and milk samples were obtained on day 0 and 14 of lactation, respectively. Fecal samples were collected from the sows on day 107 of gestation as well as day 7 and 20 of lactation to determine fecal moisture content. The results showed that the survival percentage of piglets and the litter weight at weaning were decreased linearly (p<0.05) and other parameters of the sow or litter performance were not influenced (p>0.05) by MgSO₄ supplementation. The fecal moisture content of the sows were increased (p<0.05) linearly as dietary MgSO₄ increased on day 7 and 20 of lactation. Supplementation with MgSO₄ increased the plasma magnesium (Mg) level linearly (p<0.05) and had a trend to increase total protein level (p>0.05 and p<0.10). However, an increase in the dietary MgSO₄ level resulted in a linear decrease in the colostrum fat content (p<0.05). Dietary MgSO₄ supplementation enhanced the immunoglobulin G (IgG) level (linear, p<0.05) in plasma on day of farrowing and immunoglobulin A (IgA) level in colostrum (quadratic, p<0.05) and milk (linear, p<0.05) of the sows. These results indicated that supplementation with MgSO₄ during late gestation and lactation may have the potential to prevent sow constipation, but may also result in some negative effects.

Functional characterization of the Ginkgo biloba chalcone synthase gene promoter in transgenic tobacco

The regulative sequence (2273 bp) of the chalcone synthase gene promoter of biloba was cloned by genomic walking. A 2273-bp promoter 5' upstream translation start site of GbCHS was cloned and designated as GbCHSP. pBI121+CHSP:GUS and pBI121-35S:GUS were constructed and transformed into tobacco by LBA4404. We found that GbCHSP could drive transient expression of GUS in tobacco and differentially expressed in root, stem and leaf tissues of this plant. GUS activity regulated by the CHSP promoter were located in tissues (apical meristems) at the growing points of roots and stems. pBI121+CHSP:GUS could be induced by wounding, copper, UV-B, abscisic acid, and ethephon treatments of transgenic seedlings. This activity was weakly inhibited by gibberellin. Deletion analysis of the CHSP promoter in transgenic tobacco showed that CHSP1 complete promoter conferred a GUS expression and activity similar to that of 35 S(CaMV). GUS activity dropped dramatically when there were CHSP4, CHSP5 constructs and was almost totally absent when the CHSP6 construct was present. We conclude that the upstream sequence -1548 to -306 of GbCHSP is the main region for transcriptional regulation of the CHS gene and that it is activated by hormone and stress factors in G. biloba. These results will help us to understand the transcriptional regulatory mechanisms involved in GbCHS expression and flavonoid accumulation in G. biloba.

Effectiveness of maifanite in reducing the detrimental effects of cadmium on growth performance, cadmium residue, hematological parameters, serum biochemistry, and the activities of antioxidant enzymes in pigs

This study was conducted to investigate the toxicity of cadmium and to evaluate the effectiveness of maifanite in preventing cadmium-induced adverse effects. Thirty-two crossbred pigs (Duroc × Landrace × Large white, sex balanced, 17.25 ± 0.07 kg average body weight) were randomly allotted to one of four dietary treatments in a 2 × 2 factorial arrangement, with eight replicates per treatment and one pig per replicate. The dietary treatments included two cadmium (as CdCl2) doses (0.32 and 30.49 mg/kg) and two maifanite doses (0 and 1%). The results showed that pigs treated with cadmium decreased their average daily feed intake (P < 0.05) and increased (P < 0.05) the feed/gain ratio. Cadmium was found in the tissues of pigs that were fed with cadmium-contaminated diets, but the level of cadmium was much lower when maifanite was added to the cadmium-contaminated diets. Ingestion of diets that were artificially contaminated with cadmium (30.49 mg/kg of cadmium) reduced (P < 0.05) the number of lymphocytes, the total erythrocyte count, the hemoglobin level, and the hematocrit. However, the activities of serum aspartate aminotransferase and gamma glutamyltransferase were increased (P < 0.05). The total protein level was lower (P < 0.05) in pigs fed with cadmium-contaminated diets. The contents of malondialdehyde increased (P < 0.05), while the total antioxidant capacity and the activities of total superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and catalase decreased (P < 0.05) in pigs fed with cadmium-contaminated diets. Dietary addition of maifanite can, to some extent, prevent the negative effects associated with feeding cadmium diets (30.49 mg/kg of cadmium) to pigs.

EGFRvIII stimulates glioma growth and invasion through PKA-dependent serine phosphorylation of Dock180

Glioblastomas (GBMs), the most common and malignant brain tumors, are highly resistant to current therapies. The failure of targeted therapies against aberrantly activated oncogenic signaling, such as that of the EGFR-PI3K/Akt pathway, underscores the urgent need to understand alternative downstream pathways and to identify new molecular targets for the development of more effective treatments for gliomas. Here, we report that EGFRvIII (ΔEGFR/de2-7EGFR), a constitutively active EGFR mutant that is frequently co-overexpressed with EGFR in clinical GBM tumors, promotes glioma growth and invasion through protein kinase A (PKA)-dependent phosphorylation of Dock180, a bipartite guanine nucleotide exchange factor (GEF) for Rac1. We demonstrate that EGFRvIII induces serine phosphorylation of Dock180, stimulates Rac1 activation and glioma cell migration. Treatments of glioma cells using the PKA inhibitors H-89 and KT5720, overexpression of a PKA inhibitor (PKI), and in vitro PKA kinase assays show that EGFRvIII induction of serine phosphorylation of Dock180 is PKA-dependent. Significantly, PKA induces phosphorylation of Dock180 at amino acid residue S1250 that resides within its Rac1-activating DHR-2 domain. Expression of the Dock180(S1250L) mutant, but not wild type Dock180(WT), protein in EGFRvIII-expressing glioma cells inhibited receptor-stimulated cell proliferation, survival, migration in vitro and glioma tumor growth and invasion in vivo. Together, our findings describe a novel mechanism by which EGFRvIII drives glioma tumorigenesis and invasion through PKA-dependent phosphorylation of Dock180, thereby suggesting that targeting EGFRvIII-PKA-Dock180-Rac1 signaling axis could provide a novel pathway to develop potential therapeutic strategies for malignant gliomas.

Molecular cloning and characterization of GbDXS and GbGGPPS gene promoters from Ginkgo biloba

Ginkgolides are key pharmaceutical components in Ginkgo biloba leaves. 1-Deoxy-D-xylulose-5-phosphate synthase (GbDXS) and geranylgeranyl pyrophosphate (GbGGPPS) genes are critical genes involved in ginkgolide biosynthesis. In this study, the promoters of GbDXS and GGPPS, with 676 and 570 bp in length, respectively, were cloned by chromosome walking. The cis-elements of GbDXS and GbGGPPS promoters were predicted and analyzed by the plant cis-acting regulatory element (CARE) database. We found some major cis-elements in the sequence of GbDXS and GbGGPPS promoters. The GbDXS promoter has 3 TATA boxes, 10 CAAT boxes, 6 GATA boxes, and 1 I box. The GbGGPPS promoter has 1 TATA box, 6 CAAT boxes, 6 GATA boxes, and 4 I boxes. Furthermore, some stress-related cis-elements in the promoters of GbDXS and GbGGPPS were found to be light-regulated elements, including sequences over-represented in light-induced promoters (SORLIP1- AT), GATA box, and I box, a gibberellin-responsive element (WRKY), salicylic acid-induced (GT-1), cold- and dehydration-responsive (MYC-Core), and copper-inducible (CURE-Core). Further analyses of these cis-elements will aid in elucidating the molecular mechanisms regulating the expression of the GbDXS and GbGGPPS genes during ginkgolide accumulation in G. biloba.

Changes in first hip fracture rates in British Columbia Canada, 1990-2004

We determined age-standardized first hip fracture rates in British Columbia between 1990 and 2004. We found sex and fracture type rates in keeping with previous reports and that fracture rates have decreased approximately 18% overall in both men and women.

INTRODUCTION

To determine whether there have been changes in the age-, sex-, and subtype-specific first hip fracture rates in Canadian province of British Columbia (BC) between 1990 and 2004.

METHODS

Records of all persons aged 60 years and older hospitalized with hip fractures in BC between 1985 and 2004 were obtained from the Canadian Institute for Health Information Discharge Abstract Database. Only the first hip fracture records were included, and fractures likely due to causes other than trauma were excluded. Age- and sex-specific rates were calculated using population denominators from Statistics Canada and direct standardization was used. Age-standardized rates allowed for comparison across years with adjustment for age distribution.

RESULTS

There were 41,990 records of first hip fracture included, and 73% were in women. Trends in age-specific rates by fracture type were similar to previous reports. Between 1990 and 2004, there has been an age-adjusted 18% decrease in first hip fracture rates in women, and 19% decrease in first hip fracture rates in men. The decrease was statistically significant in femoral neck fractures in women, but not in men.

CONCLUSIONS

There has been a decrease in age-adjusted hip fracture rates in BC between 1990 and 2004, which is in contrast to previous projections for hip fracture rates in Canada.

Geographic trends in incidence of hip fractures: a comprehensive literature review

A comprehensive review of literature was conducted to investigate variation in hip fracture incident rates around the world. The original crude incidence rates were standardized for age and sex for comparability. After standardization, the highest rates of hip fracture were found in Scandinavia and the lowest rates in Africa.

INTRODUCTION

This study was conducted to investigate the geographic trends of the incidence of osteoporotic hip fractures through a comprehensive review of literature.

METHODS

Studies were identified for inclusion in the review by searching the MEDLINE database via PubMed and applying strict inclusion and exclusion criteria. Age-specific incidence rates were extracted from the articles, and in order to provide a common platform for analysis, we used directly age-standardized and age-sex-standardized rates (using the 2005 United Nations estimates of the world population as standard) to complete the analysis.

RESULTS

Forty-six full text articles spanning 33 countries/regions were included in the review. For ease of comparison, the results were analyzed by geographic regions: North America, Latin America, Scandinavia, Europe (excluding Scandinavia), Africa, Asia, and Australia. The highest hip fracture rates were found in Scandinavia and the lowest in Africa. We found comparable rates from countries in North America, Australia, and Europe outside of Scandinavia. The diverse makeup of the Asian continent also resulted in quite variable hip fracture rates: ranging from relatively high rates in Iran to low rates, comparable to those from Africa, in mainland China.

CONCLUSIONS

Given the aging of populations globally, and in the industrialized countries specifically, hip fractures will become a progressively larger public health burden. The geographic trends observed in hip fracture incidence rates can provide important clues to etiology and prevention.

Activation of tumor cell proliferation by thyroid hormone in a mouse model of follicular thyroid carcinoma

Thyroid cancers are the most common malignancy of the endocrine system in humans. To understand the molecular genetic events underlying thyroid carcinogenesis, we have generated a mouse model that spontaneously develops follicular thyroid carcinoma similar to human thyroid cancer (Thrb(PV/PV) mouse). This mutant mouse harbors a dominant-negative mutated thyroid hormone receptor β (denoted PV). The PV mutation was identified in a patient with resistance to thyroid hormone (TH). Thrb(PV/PV) mice exhibit highly elevated serum thyroid-stimulating hormone levels and increased TH. We have previously shown that thyroid-stimulating hormone is required, but not sufficient to induce metastatic follicular thyroid cancer in Thrb(PV/PV) mice. However, whether the elevated TH also contributes to the thyroid carcinogenesis of Thrb(PV/PV) mice was not elucidated. To understand the role of TH in thyroid carcinogenesis, we blocked the production of TH by treating Thrb(PV/PV) mice with propylthiouracil (Thrb(PV/PV)-PTU mice) and compared the development of thyroid cancer in Thrb(PV/PV)-PTU and untreated Thrb(PV/PV) mice. We found that thyroid tumor growth was reduced by ∼42% in Thrb(PV/PV)-PTU mice as compared with Thrb(PV/PV) mice. Analysis by bromodeoxyuridine-nuclear labeling showed decreased incorporation of bromodeoxyuridine in thyroid tumor cells of Thrb(PV/PV)-PTU mice, indicative of decreased tumor cell proliferation. However, cleaved-caspase 3 staining showed no apparent changes in apoptosis of tumor cells in Thrb(PV/PV)-PTU mice. Molecular studies identified a marked attenuation of the PI3K-AKT-β-catenin signaling pathway that led to decreased protein levels of cyclin D2, thereby decreasing tumor cell proliferation in Thrb(PV/PV)-PTU mice. Furthermore, matrix metalloproteinase-2, a downstream target of β-catenin and a key regulator during tumor invasion and metastasis, was also decreased. Thus, the present study uncovers a critical role of TH in promoting the thyroid carcinogenesis of Thrb(PV/PV) mice via membrane signaling events. Importantly, these findings suggest that anti-thyroid drugs could be considered as possible therapeutic agents of thyroid cancer.

Play fighting and corticotropin-releasing hormone in the lateral septum of golden hamsters

This study was focused on determining the possible role of corticotropin-releasing hormone (CRH) on play fighting in juvenile golden hamsters. As no specific neural sites have been proposed, we looked for changes in CRH innervations at the peak of play-fighting activity on postnatal day 35 (P-35) from a week before on P-28. We noted that the increase in play-fighting activity between these two dates was associated with a 100% increase of the density of CRH fibers within the lateral septum. We, then, tested the possible role of CRH receptors on play fighting within the lateral septum through microinjections of alpha-helical CRH, a CRH receptor antagonist (either 0, 30, or 300 ng), directly into the area. The treatments inhibited play-fighting attacks and pins as well as reduced the duration of time that the resident hamsters spent in contact with the intruders, though locomotor activity remained unaffected. The possible source of CRH release in the lateral septum was addressed by quantification of CRH neurons also labeled with a marker of cellular activity, c-Fos, after consummation of play fighting. CRH neurons in the horizontal part of the diagonal band, an area reciprocally connected with the lateral septum, showed a 75% increase in double labeling with c-Fos as compared to controls. Together, these data show that CRH receptors in the lateral septum have a general role on play fighting, not just facilitating its consummation, but also likely enhancing appetitive aspects as well. In addition, this effect is associated with enhanced CRH availability in the area and enhanced neuronal activity within interconnected areas.

CALHM1 variant is not associated with Alzheimer's disease among Asians

In a case control study involving 484 study subjects, we showed that the CALHM1 allele (13.5% vs 16.7%) and genotype frequency was not significantly different between Alzheimer's disease (AD) and controls. Logistic regression analysis did not reveal any interaction between ApoE4 allele and CALHM1 allele.

Modeling thyroid cancer in the mouse

Thyroid carcinomas, the most common endocrine tumors in humans, have an increasing incidence in the U.S. and worldwide. There are four major types of thyroid cancers: papillary, follicular, anaplastic, and medullary carcinomas. In recent years, significant progress has been made in the identification of genetic alterations in thyroid carcinomas, particularly, papillary and medullary thyroid cancers. Mouse models of thyroid cancer are valuable tools in elucidating molecular genetic changes underlying thyroid carcinogenesis and in identifying potential molecular targets for therapeutic intervention. Representative mouse models of papillary, follicular, and medullary carcinomas are reviewed here with particular emphasis on those for follicular thyroid carcinomas. Challenges for further development in the modeling of thyroid cancer will also be discussed.

Distinct dysregulation of lipid metabolism by unliganded thyroid hormone receptor isoforms

Thyroid hormone receptors (TRs) play critical roles in energy homeostasis. To understand the role of TRs in lipid homeostasis in vivo, we adopted the loss-of-function approach by creating knock-in mutant mice with targeted mutation in the TRalpha gene (TRalpha1PV mouse) or TRbeta gene (TRbetaPV mouse). The PV mutation, identified in a patient with resistance to thyroid hormone, exhibits potent dominant-negative activity. Here we show that in contrast to TRalpha1PV mouse, TRbetaPV mice exhibited no significant reduction in WAT but had significant increases in serum free fatty acids and total triglycerides. Moreover, the liver of TRbetaPV mice was markedly increased (33%) with excess lipid accumulation, but the liver mass of TRalpha1PV mouse was decreased (23%) with paucity of lipids. These results indicate that apo-TRbeta and apo-TRalpha1 exerted distinct abnormalities in lipid metabolism. Further biochemical analyses indicate that increased lipogenic enzyme expression, activated peroxisome proliferator-activated receptor gamma (Ppargamma) signaling, and decreased fatty acid beta-oxidation activity contributed to the adipogenic steatosis and lipid accumulation in the liver of TRbetaPV mice. In contrast, the expression of lipogenic enzymes and Ppargamma was decreased in the liver of TRalpha1PV mice. These results suggest that the regulation of genes critical for lipid metabolism by TRs in the liver is isoform dependent. These results indicate that apo-TRbeta and apo-TRalpha1 had different effects on lipid metabolism and that both TR isoforms contribute to the pathogenesis of lipid metabolism in hypothyroidism.

Hedgehog signaling promotes the degradation of tumor suppressor Sufu through the ubiquitin-proteasome pathway

Sustained Sonic hedgehog (Shh) pathway activity is associated with tumorigenesis in a wide variety of tissues. Mutational inactivation of Shh receptor Patched (Ptch) and a downstream gene Suppressor of fused (Sufu), both of which are negative regulators of the pathway, increases susceptibility to cerebellum cancer in humans and mice. Sufu is a binding partner of Shh pathway transcription factor Gli. Recent data indicate that inactivation of Sufu, through either gene targeting in mice or RNAi-mediated silencing in cultured fibroblasts, is sufficient to turn on Shh target gene expression. Here, we report that Sufu is degraded rapidly in certain cancer cells and we show that Shh signaling promotes ubiquitination of Sufu, which leads to its destruction in the proteasomes. We identified an ubiquitin attachment site on K257 of Sufu, and showed that Sufu-K257R mutant is more potent as a transcription repressor and cell growth inhibitor because of increased stability. These results indicate that Shh signaling regulates Sufu activity by inducing its turnover via the ubiquitin-proteasome system.

PTEN deficiency accelerates tumour progression in a mouse model of thyroid cancer

Inactivation and silencing of PTEN have been observed in multiple cancers, including follicular thyroid carcinoma. PTEN (phosphatase and tensin homologue deleted from chromosome 10) functions as a tumour suppressor by opposing the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signalling pathway. Despite correlative data, how deregulated PTEN signalling leads to thyroid carcinogenesis is not known. Mice harbouring a dominant-negative mutant thyroid hormone receptor beta (TRbeta(PV/PV) mice) spontaneously develop follicular thyroid carcinoma and distant metastases similar to human cancer. To elucidate the role of PTEN in thyroid carcinogenesis, we generated TRbeta(PV/PV) mice haploinsufficient for Pten (TRbeta(PV/PV)Pten(+/-) mouse). PTEN deficiency accelerated the progression of thyroid tumour and increased the occurrence of metastasis spread to the lung in TRbeta(PV/PV)Pten(+/-) mice, thereby significantly reducing their survival as compared with TRbeta(PV/PV)Pten(+/+) mice. AKT activation was further increased by two-fold in TRbeta(PV/PV)Pten(+/-) mice thyroids, leading to increased activity of the downstream mammalian target of rapamycin (mTOR)-p70S6K signalling and decreased activity of the forkhead family member FOXO3a. Consistently, cyclin D1 expression was increased. Apoptosis was decreased as indicated by increased expression of nuclear factor-kappaB (NF-kappaB) and decreased caspase-3 activity in the thyroids of TRbeta(PV/PV)Pten(+/-) mice. Our results indicate that PTEN deficiency resulted in increased cell proliferation and survival in the thyroids of TRbeta(PV/PV)Pten(+/-) mice. Altogether, our study provides direct evidence to indicate that in vivo, PTEN is a critical regulator in the follicular thyroid cancer progression and invasiveness.

Neural circuitry of play fighting in golden hamsters

In hamsters, play fighting matures gradually into adult aggression. As these two behaviors share many similarities in this species, we predicted that a single neural circuitry controls their offensive component. The goal of the present study was to identify neural systems associated with offensive play fighting in male juvenile golden hamsters. The neural circuitry related to this behavior was identified through quantification of c-Fos immunolabeling. We also looked for vasopressin cells possibly associated with play fighting. We found that areas previously associated with offensive aggression in adult hamsters, including the ventrolateral hypothalamus, the medial amygdala, and the bed nucleus of the stria terminalis, also showed enhanced c-Fos expression after play fighting. In addition, vasopressin neurons in the nucleus circularis and the medial division of the supraoptic nucleus expressed enhanced c-Fos immunolabeling in juveniles after play fighting, as previously reported in adult hamsters after aggression. Finally, enhanced c-Fos expression associated with play fighting was also found in areas previously unexplored in adult hamsters, such as the prefrontal cortex. Together, our results support the hypothesis of a single core neural circuitry controlling the offensive components of play fighting and adult aggression throughout puberty in hamsters.

Good death study of elderly patients with terminal cancer in Taiwan

OBJECTIVES

Over half of all terminal cancer patients in Taiwan are 65 or older, thus demonstrating the importance of terminal care for elderly people. This study investigates the good death status of elderly patients with terminal cancer, comparing the differences in the degree of good death among elderly and younger groups, and exploring the factors related to the good death score.

METHODS

Three hundred and sixty-six patients with terminal cancer admitted to a palliative care unit were enrolled. Two structured measurements, the good death scale and the audit scale for good death services, were used as the instruments in the study.

RESULTS

The scores of individual items and of the good death scale were increased significantly in both elderly (n = 206, 56.3%) and younger (n = 160, 43.7%) groups from the time of admission to just prior to death. However, the elderly group had significantly lower scores in 'awareness' (t = -3.76, P < 0.001), 'propriety' (t = -2.92, P < 0.01) and 'timeliness' (t = -2.91, P < 0.01) than the younger group prior to death. Furthermore, because of a lack of truth-telling, the elderly group also had significantly lower scores than the younger group in both 'respect for autonomy' and 'decision-making participation' (t = -2.17, P < 0.05; t = -2.21, P < 0.05, respectively). Multiple regression analysis revealed that 'respect for autonomy' (OR = 1.22, 95% CI = 0.76-1.67) and 'verbal support '(OR = 0.93, 95% CI = 0.34-1.51) were two independent correlates of the good death score in the elderly group.

CONCLUSION

The dilemma of truth-telling compromises the autonomy of the elderly patients with terminal cancer and consequently affects their good death scores. The palliative care team should emphasize the issue of truth-telling in the process of caring for terminally ill cancer patients, especially elderly patients.

Silencing Livin gene expression to inhibit proliferation and enhance chemosensitivity in tumor cells

Livin, a novel member of the human inhibitors of apoptosis protein (IAP) family, plays an important role in tumor progression and occurrence by inhibiting cell apoptosis. It is selectively expressed in the most common human neoplasms and appears to be involved in tumor cell resistance to chemotherapeutic agents. To investigate its possibility as a therapeutic target for human malignancies, we established two genetically different stable tumor cell lines (LoVo and SPCA-1) and RNA interference (RNAi) technique was employed to downregulate Livin expression in two human tumor cell lines. The specific downregulation of Livin expression in tumor cell lines significantly inhibited in vitro cell proliferation and in vivo tumorigenicity. Furthermore, Livin knockdown led to cell arrest in the G(1)/G(0) phase of cell cycle, eventual apoptosis and chemosensitivity enhancement in tumor cells. All these results indicate that RNAi-mediated downregulation of Livin expression can lead to potent antitumor activity and chemosensitizing effects in human cancers.

Adrenocorticotropic hormone elevates gene expression for catecholamine biosynthesis in rat superior cervical ganglia and locus coeruleus by an adrenal independent mechanism

Classically, upon hypothalamic stimulation, adrenocorticotropic hormone (ACTH) is released from the pituitary and acts on melanocortin 2 receptors (MC2R) in the adrenal cortex, stimulating glucocorticoid synthesis and release. Our earlier studies suggested that ACTH might have a direct effect on sympathetic ganglia. To analyze further the involvement of ACTH in regulation of gene expression of norepinephrine (NE) biosynthetic enzymes, we examined the effect of bilateral adrenalectomy (ADX) of Sprague-Dawley male rats. Fourteen days post-ADX, as expected, plasma ACTH was elevated, and levels of tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH) and MC2R mRNAs in superior cervical ganglia (SCG), and TH mRNA in locus coeruleus (LC) were increased compared with sham-operated animals. To determine effect of pulsatile elevation of ACTH, corticosterone pellets were implanted to ADX rats. Similar to immobilization (IMO) stress ACTH injections to these animals caused a rise in ACTH in plasma and triggered elevation of TH and DBH mRNAs in SCG and in LC with single and repeated daily injections, and MC2R mRNA in SCG with single injections. To study the effect of ACTH in isolated cells, primary cultures of rat SCG were transfected with TH and DBH promoter constructs and treated with ACTH. In agreement with the in vivo data, ACTH elevated their promoter activities similar to levels triggered by cyclic AMP analog. ACTH in the human SK-N-SH neuroblastoma cells increased TH and DBH promoter activity and endogenous DBH mRNA levels. The results show that ACTH can have a direct effect on transcription and gene expression of NE biosynthetic enzymes even without contribution of adrenal hormones.

Separase, securin and Rad21 in neural cell growth

The key mitotic regulator securin is expressed at low levels in fetal brain compared with adult, and modulates the proliferation of human embryonic neuronal N-Tera2 (NT2) cells. We now examine the function and expression of securin's interacting partner separase, along with Rad21, the functional component of cohesin, which is cleaved by separase following interaction with securin. In contrast to securin, the cleaved forms of separase and Rad21 were highly expressed in human fetal cerebral cortex compared with adult. In a murine model of absent securin expression - the PTTG knock-out mouse - separase and Rad21 were over-expressed in multiple brain regions. In addition, cDNA array analysis of other key mitotic regulators additionally identified cyclin C and sestrin 2 to be induced in the brains of securin-null mice compared with wild type. Further, Rad21 mRNA expression was highly correlated with that of securin, separase, cyclin C and sestrin 2 in fetal brains. In embryonic neuronal NT2 cells, siRNA repression of separase failed to significantly alter cell turnover, whereas repression of securin expression resulted in increased levels of the activated forms of Rad21 and separase, and promoted cell proliferation. Our data suggest that the co-ordinated expression of separase, securin and Rad21 is fundamental for the developing brain.

Effect of microwave annealing temperatures on lead zirconate titanate thin films

Lead zirconate titanate (Pb(1.1)(Zr(0.52)Ti(0.48))O(3)) thin films of thickness 260 nm on Pt/Ti/SiO(2)/Si substrates were densified by 2.45 GHz microwave annealing. The PZT thin films were annealed at various annealing temperatures from 400 to 700 °C for 30 min. X-ray diffraction showed that the pyrochlore phase was transformed to the perovskite phase at 450 °C and the film was fully crystallized. The secondary (again pyrochlore) phase was observed in the PZT thin films, which were annealed above 550 °C. The surface morphologies were changed above 550 °C of the PZT thin films due to the secondary phase. Higher dielectric constant (ε(r)) and lower dielectric loss coercive field (E(c)) were achieved for the 450 °C film than for the other annealed films.

The steroid receptor coactivator-3 is a tumor promoter in a mouse model of thyroid cancer

The molecular genetic events underlying thyroid carcinogenesis are not well understood. Mice harboring a dominant-negative mutant thyroid hormone receptor-beta (TRbeta(PV/PV) mice) spontaneously develop follicular thyroid carcinoma similar to human cancer. The present study aimed to elucidate the role of the steroid receptor coactivator-3 (SRC-3) in thyroid carcinogenesis in vivo by using the offspring from the cross of TRbeta(PV/PV) and SRC-3(-/-) mice. TRbeta(PV/PV) mice deficient in SRC-3 (TRbeta(PV/PV)SRC-3(-/-) mice) had significantly increased survival, decreased thyroid tumor growth, delayed tumor progression and lower incidence of distant metastasis as compared with TRbeta(PV/PV) mice with SRC-3 (TRbeta(PV/PV)SRC-3(+/+) mice). Further, in vivo and in vitro analyses of multiple signaling pathways indicated that SRC-3 deficiency could lead to (1) inhibition of cell cycle progression at the G(1)/S transition via controlling the expression of cell cycle regulators, such as E2F1; (2) induction of apoptosis by controlling the expression of the Bcl-2 and caspase-3 genes and (3) suppression of neovascularization and metastasis, at least in part, through modulating the vascular endothelial growth factor gene expression. Taken together, SRC-3 could play important roles through regulating multiple target genes and signaling pathways during thyroid carcinogenesis, understanding of which should direct future therapeutic options for thyroid cancer.

Endothelial dysfunction in a murine model of thyroid hormone resistance

BACKGROUND

The development of a knockin mouse model of resistance to thyroid hormone (RTH) has led to a greater understanding of both the molecular and clinical behaviour of this syndrome. We have investigated the vascular response in RTH using a specific (TRbeta PV) knockin mouse model targeting the PV mutation to the thyroid hormone receptor beta gene locus.

MATERIALS AND METHODS

Ring segments of the thoracic aorta were used to assess the response of homozygous, heterozygous and wild-type controls to contractile agents, potassium chloride and phenylephrine. Each genotype after maximal contraction was exposed to increasing concentrations of relaxing agents, acetylcholine (ACh) and sodium nitroprusside (SNP).

RESULTS

The response of these aortic ring segments to ACh and SNP demonstrates that endothelium-dependent relaxation to ACh was significantly impaired in both heterozygous and homozygous mice compared to controls (69.8 +/- 2.0%, 59.7 +/- 1.4% and 75.0 +/- 1.7%, respectively; P < 0.001). However, endothelium independent responses to SNP showed no difference between genotypes (114.4 +/- 3.2%, 116.8 +/- 2.6% and 106.9 +/- 4.9%; P = NS).

CONCLUSION

These data suggest that endothelial function is impaired in the RTH mouse aorta. The respective roles of elevated thyroid stimulating hormone (TSH), elevated thyroid hormone concentrations and the mutated thyroid hormone beta receptor require further elucidation.

Neuropilin-1 promotes human glioma progression through potentiating the activity of the HGF/SF autocrine pathway

Neuropilin-1 (NRP1) functions as a coreceptor through interaction with plexin A1 or vascular endothelial growth factor (VEGF) receptor during neuronal development and angiogenesis. NRP1 potentiates the signaling pathways stimulated by semaphorin 3A and VEGF-A in neuronal and endothelial cells, respectively. In this study, we investigate the role of tumor cell-expressed NRP1 in glioma progression. Analyses of human glioma specimens (WHO grade I-IV tumors) revealed a significant correlation of NRP1 expression with glioma progression. In tumor xenografts, overexpression of NRP1 by U87MG gliomas strongly promoted tumor growth and angiogenesis. Overexpression of NRP1 by U87MG cells stimulated cell survival through the enhancement of autocrine hepatocyte growth factor/scatter factor (HGF/SF)/c-Met signaling. NRP1 not only potentiated the activity of endogenous HGF/SF on glioma cell survival but also enhanced HGF/SF-promoted cell proliferation. Inhibition of HGF/SF, c-Met and NRP1 abrogated NRP1-potentiated autocrine HGF/SF stimulation. Furthermore, increased phosphorylation of c-Met correlated with glioma progression in human glioma biopsies in which NRP1 is upregulated and in U87MG NRP1-overexpressing tumors. Together, these data suggest that tumor cell-expressed NRP1 promotes glioma progression through potentiating the activity of the HGF/SF autocrine c-Met signaling pathway, in addition to enhancing angiogenesis, suggesting a novel mechanism of NRP1 in promoting human glioma progression.

Transgenic mice expressing a human mutant beta1 thyroid receptor are hyperactive, impulsive, and inattentive

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed childhood psychiatric disorder. We have found that a transgenic mouse bearing a human mutant thyroid receptor (TRbeta1) expresses all of the defining symptoms of ADHD--inattention, hyperactivity, and impulsivity--as well as a 'paradoxical' response to methylphenidate (MPH). As with ADHD, the behavioral phenotypes expressed by the TRbeta transgenic mice are dynamic and sensitive to changes in environmental conditions, stress, and reinforcement. TRbeta transgenic mice are euthyroid except for a brief period during postnatal development, but the behavioral phenotypes, elevated dopamine turnover, and paradoxical response to MPH persist into adulthood. Thus, like the vast majority of children with ADHD, the TRbeta transgenic mice exhibit the symptoms of ADHD in the complete absence of thyroid abnormalities. This suggests that even transient perturbations in developmental thyroid homeostasis can have long-lasting behavioral and cognitive consequences, including producing the full spectrum of symptoms of ADHD.

PPARgamma insufficiency promotes follicular thyroid carcinogenesis via activation of the nuclear factor-kappaB signaling pathway

The molecular genetic events underlying thyroid carcinogenesis are poorly understood. Mice harboring a knock-in dominantly negative mutant thyroid hormone receptor beta (TRbetaPV/PV mouse) spontaneously develop follicular thyroid carcinoma similar to human thyroid cancer. Using this mutant mouse, we tested the hypothesis that the peroxisome proliferator-activated receptor gamma (PPARgamma) could function as a tumor suppressor in thyroid cancer in vivo. Using the offspring from the cross of TRbetaPV/+ and PPARgamma+/- mice, we found that thyroid carcinogenesis progressed significantly faster in TRbetaPV/PV mice with PPARgamma insufficiency from increased cell proliferation and reduced apoptosis. Reduced PPARgamma protein abundance led to the activation of the nuclear factor-kappaB signaling pathway, resulting in the activation of cyclin D1 and repression of critical genes involved in apoptosis. Treatment of TRbetaPV/PV mice with a PPARgamma agonist, rosiglitazone, delayed the progression of thyroid carcinogenesis by decreasing cell proliferation and activation of apoptosis. These results suggest that PPARgamma is a critical modifier in thyroid carcinogenesis and could be tested as a therapeutic target in thyroid follicular carcinoma.

Use of glucose-responsive material to regulate insulin release from constitutively secreting cells

Genetically-engineered cells offer a solution to the cell availability problem in tissue engineering a pancreatic substitute for the treatment of insulin-dependent diabetes. These cells can be non-beta cells, such as hepatocytes or myoblasts, retrieved as a biopsy from the same patient and genetically engineered to secrete recombinant insulin constitutively or under transcriptional regulation. However, the continuous or slowly responsive insulin secretion dynamics from these cells cannot provide physiologic glucose regulation in patients. Our objective consists of using such cells as an insulin source and of regulating insulin release by incorporating a glucose-responsive material, which acts as a control barrier for insulin in a cell-material hybrid device. Experiments were performed with insulinoma betaTC3 cells, HepG2 hepatomas, and C2C12 myoblasts, the latter two genetically-modified to constitutively secrete insulin. The control barrier consisted of concanavalin A (con A)-based glucose-responsive material, which forms a gel at low and a sol at high glucose concentrations. Results demonstrated that the device released insulin at a higher rate in response to glucose challenges. In contrast, a device containing an inert hydrogel instead of glucose-responsive material released insulin at an essentially constant rate, irrespective of the surrounding glucose concentration. Necessary material improvements include increased sensitivity to glucose, so that the material responds to physiologically relevant glucose concentrations, and increased stability. The prospects of developing a properly functional, implantable substitute based on engineered non-beta cells and glucose-responsive material, and the material and device improvements that need to be made prior to in vivo experiments, are discussed.

Hybrid pancreatic tissue substitute consisting of recombinant insulin-secreting cells and glucose-responsive material

Insulin-dependent diabetes is a serious pathological condition, currently treated by blood glucose monitoring and daily insulin injections, which, however, do not prevent long-term complications. A tissue-engineered pancreatic substitute has the potential to provide a more physiologic, less invasive, and potentially less costly treatment of the disease. A major issue in developing such a substitute is the cells being used. Nonpancreatic cells, retrieved from the same patient and genetically engineered to secrete insulin constitutively or with some glucose responsiveness, offer the significant advantages of being immune-acceptable and relaxing the tissue availability limitations, which exist with islets from cadaveric donors. These cells, however, do not have insulin secretion dynamics appropriate for restoration of euglycemia in higher animals and, eventually, humans. In this study, we present the concept of a hybrid pancreatic substitute consisting of such cells sequestered in a material exhibiting glucose-dependent changes of its permeability to insulin. A Concanavalin A-glycogen material sandwiched between two polycarbonate membranes and exhibiting glucose-dependent sol-gel transformations was used. Rates of insulin transport through this material in gel and sol forms were characterized for both FITC-labeled insulin in solution and insulin secreted by betaTC3 mouse insulinoma cells. Effective diffusivities through sol were found to be up to 3.5-fold higher than through the gel state of the material. A mathematical model of a hybrid construct was formulated and analyzed to simulate the secretory behavior in response to step ups and downs in the surrounding glucose concentration. The experimental and modeling studies indicate that a hybrid pancreatic substitute consisting of constitutively secreting cells and glucose-responsive material has the potential to provide a more physiologic regulation of insulin release than the cells by themselves or in an inert material.

Increased production and excretion of urea in the kuruma shrimp (Marsupenaeus japonicus) exposed to combined environments of increased ammonia and nitrite

Marsupenaeus japonicus (6.37 +/- 1.29 g) individually exposed to 9 different combined solutions of ambient ammonia (C) and nitrite (C') ammonia at 0.003 [control], 0.39, and 1.49 mmol/L combined with nitrite at 0.001 [control], 0.38, and 1.49 mmol/L in 30 ppt were examined for nitrogenous excretion accumulations of ammonia, nitrite, urea, and uric acid in tissues after 48 hours. M. japonicus exposed to 0.39 mmol/L ammonia-0.38 mmol/L nitrite displayed higher levels of urea-nitrogen (UNE) and organic-N (ONE) excretion by a factor of 2.2 and 5.7, respectively, compared with shrimp exposed only to 0.39 mmol/L ammonia. Exposure to 0.39 mmol/L ammonia-0.38 mmol/L nitrite resulted in lower levels of hemolymph uric acid (HUA), gill ammonia (GAM), gill urea (GUE), gill uric acid (GUA), hepatopancreas ammonia (HPAM), hepatopancreas urea (HPUE), and hepatopancreas uric acid (APUA), respectively, compared with shrimp exposed only to 0.39 mmol/L ammonia. We concluded that M. japonicus exposed to combined environments of ammonia and nitrite display increased nitrogen metabolism and production of urea-N and other organic-N.

Overexpression of VEGF121, but not VEGF165 or FGF-1, improves oxygenation in MCF-7 breast tumours

Vascular endothelial growth factor (VEGF) is an intensively studied molecule that has significant potential, both in stimulating angiogenesis and as a target for antiangiogenic approaches. We utilised MCF-7 breast cancer cells transfected with either of two of the major VEGF isoforms, VEGF(121) or VEGF(165), or fibroblast growth factor-1 (FGF-1) to distinguish the effects of these factors on tumour growth, vascular function, and oxygen delivery. While each transfectant demonstrated substantially increased tumorigenicity and growth rate compared to vector controls, only VEGF(121) produced a combination of significantly reduced total and perfused vessel spacing, as well as a corresponding reduction in overall tumour hypoxia. Such pathophysiological effects are of potential importance, since antiangiogenic agents designed to block VEGF isoforms could in turn result in the development of therapeutically unfavourable environments. If antiangiogenic agents are also combined with conventional therapies such as irradiation or chemotherapy, microregional deficiencies in oxygenation could play a key role in ultimate therapeutic success.

The induction of amyloid precursor protein and α-synuclein in rat hippocampal astrocytes by diethyldithiocarbamate and copper with or without glutathione

alpha-Synuclein is the major component of Lewy bodies. Its aggregation can be accelerated by copper, iron, or beta-amyloid (Abeta) and has been thought to provide a nucleation center during the formation of amyloid plaques. The main structural component of amyloid plaque is Abeta, which is derived from a larger protein, amyloid precursor protein (APP). Xenobiotics have been implicated in the etiology of the neurodegenerative disease. Mechanisms of diethyldithiocarbamate (DDC) neurotoxicity involve copper chelation and interactions with SH groups resulting in oxidative stress. In this study, rat hippocampal astrocytes were treated with DDC (75 microM), CuCl(2) (0.2 microM), or DDC (75 microM) plus CuCl(2) (0.2 microM) for 1h. Cells were allowed to recover with or without 10 mM GSH. Results showed an increase of APP and alpha-synuclein production occurring in a time-dependent manner. At 4 h post-treatment, cells contained small positively stained material deposited throughout the cytosol for APP and by 8 h post-treatment increases were seen in both APP and alpha-synuclein. Immunoblots supported immunocytochemical results. Glutathione (GSH) decreased the accumulation of these proteins at 8 h post-treatment.

An integrated subsurface modeling and risk assessment approach for managing the petroleum-contaminated sites

Soil and groundwater contamination can lead to a variety of impacts and risks to the communities. Identifications of management schemes with sound environmental and socio-economic efficiencies is desired. In fact, before any decisions regarding site remediation actions can be made, three major questions may have to be answered. They include "What happened underground, and what will happen in the future under the given remediation scenarios?," "Are there specific risks on the surrounding community?" and "What remediation alternatives are suitable for the site?" In this study, an integrated subsurface modeling and risk assessment method for petroleum-contaminated site management is proposed. It incorporates multi-phase flow multi-component transport modeling and ELCR-based human health risk assessment into a general framework. The proposed method is applied to a case study within a western Canada context for identifying effective management schemes with improved environmental and socio-economic efficiencies. Given conditions at the study site, six remediation alternatives based on combinations of several technologies are recommended, with the provision of analyses for equipment/manpower requirements, system designs, operations, efficiencies, and costs. These alternatives can be categorized into two groups: hybrid ex situ and in situ remediation approaches, and integrated in situ remediation approaches. This study is a new attempt that integrates issues of subsurface-contamination simulation, risk assessment, and site remediation for a real-world problem within a general research framework. The research outputs are directly useful for the industry to gain insight of the site and to make decisions of the relevant remediation actions.

Germline and somatic thyroid hormone receptor mutations in man

Thyroid hormone plays important roles in metabolism, growth, and differentiation. Germline mutations in thyroid hormone receptor beta (TRbeta) have been identified in many individuals with resistance to thyroid hormone (RTH), a syndrome of hyposensitivity to T3. However, it has become increasingly apparent that somatic mutations can also occur in individual tissues, and are associated with tumors and malignancies in man. Herein we review the occurrence and identification of germline and somatic TR mutations and characterization of their pathological effects on hormone resistance and tumorigenesis.

Marked potentiation of the dominant negative action of a mutant thyroid hormone receptor beta in mice by the ablation of one wild-type beta allele

Mutations in the thyroid hormone receptor (TR) beta gene result in resistance to thyroid hormone (RTH), characterized by reduced sensitivity of tissues to thyroid hormone. To understand which physiological TR pathways are affected by mutant receptors, we crossed mice with a dominantly negative TRbeta mutation (TRbetaPV) with mice carrying a TRbeta null mutation (TRbeta(-/-)) to determine the consequences of the TRbetaPV mutation in the absence of wild-type TRbeta. TRbeta(PV/-) mice are distinct from TRbeta(+/-) mice that did not show abnormalities in thyroid function tests. TRbeta(PV/-) mice are also distinct from TRbeta(PV/+) and TRbeta(-/-) mice in that the latter shows mild dysfunction in the pituitary-thyroid axis, whereas the former exhibit very severe abnormalities, including extensive papillary hyperplasia of the thyroid epithelium, indistinguishable from that observed in TRbeta(PV/PV) mice. Similar to TRbeta(PV/PV) mice, TRbeta(PV/-) mice exhibited impairment in weight gain. Moreover, the abnormal regulation patterns of T3-target genes in the tissues of TRbeta(PV/-) and TRbeta(PV/PV) mice were strikingly similar. Using TR isoforms and PV-specific antibodies in gel shift assays, we found that in vivo, PV competed with TRalpha1 for binding to thyroid hormone response elements in TRbeta(PV/-) mice as effectively as in TRbeta(PV/PV) mice. Thus, the actions of mutant TRbeta are markedly potentiated by the ablation of the second TRbeta allele, suggesting that interference with wild-type TRalpha1-mediated gene regulation by mutant TRbeta leads to severe RTH.

Accumulations of nitrite and nitrate in the tissues of Penaeus monodon exposed to a combined environment of elevated nitrite and nitrate

Penaeus monodon (11.86 +/- 0.63 g) exposed individually to six different nitrite and nitrate regimes [nitrite at 0.002 (control), 0.360, and 1.455 mM combined with nitrate at 0.005 (control) and 7.275 mM] in 25 ppt sea water were examined for the nitrite and nitrate concentrations in tissues and nitrite uptake and nitrate uptake after 24 h in 25.3 degrees C. In P. monodon following exposure to 1.455 mM nitrite only, nitrite levels increased by factors of 0.33, 1.05, 1.36, 1.79, 2.10, 2.16, 2.21, and 3.58 in muscle, hepatopancreas, gill, foregut, hemolymph, heart, eyestalk, and midgut, respectively, over the ambient nitrite level. In P. monodon, following exposure to combined solutions of 1.455 mM nitrite and 7.275 mM nitrate, nitrite levels were factors of 0.34, 1.05, 1.44, 1.86, 2.21, 2.30, 2.67, and 3.83 in muscle, hepatopancreas, gill, foregut, heart, hemolymph, eyestalk, and midgut, respectively, over the ambient nitrite levels, whereas nitrate levels were factors of 0.06, 0.11, 0.27, 0.29, 0.45, 0.51, 0.57, and 0.61 in muscle, hepatopancreas, foregut, heart, hemolymph, gill, midgut, and eyestalk, respectively, over the ambient nitrate levels. It is concluded that incorporation of nitrite is converted to nitrate in midgut, heart, hemolymph, foregut, and eyestalk, whereas incorporation of nitrate in tissues is converted to nitrite and accumulated in eyestalk when P. monodon are exposed to combined nitrite and nitrate environments.

Estimation of atmospheric mixing heights over large areas using data from airport meteorological stations

For this study, ground and sounding meteorological data at 16 airports were used for estimating the atmospheric mixing heights in Hebei Province of China, including Beijing and Tanjing areas. Three methods were compared for this purpose, which are the dry adiabatic method, the conventional Nozaki model, and a modified Nozaki model. The feasibility of using airport meteorological data to determine mixing heights in large area was verified through the use of measured mixing heights and observed SO2 vertical profiles. The study not only estimated the mixing heights over large areas but also compared different early morning sounding temperature profiles to identify feasibility of using 2:00 a.m. sounding profiles to estimate mixing height by the dry adiabatic method. The paper also described the mixing heights over different areas such as mountain, sea boundary and plain areas. The results have considerable significance for air quality prediction and environmental management. A novel approach to estimation of atmospheric mixing heights over large area is introduced, requiring only the input of readily available airport meteorological data.