The expression of BTG1 is downregulated in nasopharyngeal carcinoma and possibly associated with tumour metastasis

To determine the expression and function of B cell translocation gene 1 (BTG1) in nasopharyngeal carcinoma. Nasopharyngeal samples were taken from cancer lesions (n = 75) and adjacent normal tissue (n = 33) in nasopharyngeal cancer patients immediately after endoscopic biopsy. BTG1 expression was determined by immunohistochemistry and Western blotting. The effect of BTG1 overexpression was examined in vitro utilizing a human nasopharyngeal cancer cell line CNE2 stably transfected with a recombinant lentivirus (LeBTG1 cells) and compared to empty vector-transfected controls (LeEmpty). BTG1 overexpression was verified by real-time reverse transcriptase polymerase chain reaction and Western blot. The expression of proteins involved in cell cycle regulation (cyclin D1), apoptosis (Bcl-2) and cell migration (MMP-9) in LeBTG1 cells were analyzed by Western blot. The effect of BTG1 overexpression on cell viability and proliferation was assessed by an MTT assay in LeBTG1 and LeEmpty cells. Flow cytometric analyses were used to evaluate the effect of BTG1 expression on cell cycle distribution and apoptosis. The migration and invasion potential of LeBTG1 cells was examined by plating cells in Matrigel-coated chambers. BTG1 protein expression was significantly lower in nasopharyngeal cancer tissue biopsies than normal tissue as measured by immunohistochemistry (36.0 vs. 81.8 % of tissues; P < 0.05) and Western blotting (0.221 ± 0.019 vs. 0.652 ± 0.055; P < 0.05). Decreased expression of BTG1 was significantly correlated with nasopharyngeal cancer tumor stage, lymph node metastasis, clinical stage and pathologic differentiation (P < 0.05), as well as with reduced overall five-year survival rates compared to patients with higher expression levels (31.2 vs. 70.2 %; P < 0.05). In vitro analyses revealed that LeBTG1 cells had a reduced survival fraction compared to control LeEmpty cells, with higher rates of apoptosis (9.3 ± 0.7 vs. 2.3 ± 0.3 %; P < 0.05). The proportion of LeBTG1 cells in G0/G1 stage and S phase was also significantly different from LeEmpty cells (82.6 ± 3.8 and 10.1 ± 1.0 %, vs. 62.2 ± 2.4 and 28.9 ± 2.0 %, respectively; Ps < 0.05), and the migration and invasion of LeBTG1 cells was significantly impaired with respect to LeEmpty cells (96.0 ± 13.0 and 91.0 ± 11.0 vs. 158.0 ± 17.0 and 142.0 ± 15.0, respectively; Ps < 0.05). These effects were accompanied by decreased protein expression of cyclin D1, Bcl-2 and MMP-9 in LeBTG1 cells (0.231 ± 0.021, 0.413 ± 0.046, 0.131 ± 0.011, respectively) compared to control LeEmpty cells (0.636 ± 0.067, 0.821 ± 0.083, 0.451 ± 0.041, respectively; Ps < 0.05). Reduced BTG1 expression is associated with increased disease severity, suggesting it is a negative regulator of nasopharyngeal cancer and can serve as a prognostic indicator.

BTG1 underexpression is an independent prognostic marker in esophageal squamous cell carcinoma

To determine the expression and function of B cell translocation gene 1 (BTG1) in esophageal carcinoma, esophageal samples were taken from cancer lesions (n = 74) and adjacent normal tissue (n = 34) in esophageal cancer patients immediately after endoscopic biopsy. BTG1 expression was determined by immunohistochemistry and Western blotting. The effect of BTG1 overexpression was examined in vitro utilizing a human esophageal cancer cell line ECA-109 stably transfected with a recombinant lentivirus (LeBTG1 cells) and compared to empty vector-transfected controls (LeEmpty). BTG1 overexpression was verified by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot. The expression of proteins involved in cell cycle regulation (cyclin D1) and apoptosis (Bcl-2) and cell migration (MMP-9) in LeBTG1 cells was analyzed by Western blot. The effect of BTG1 overexpression on cell viability and proliferation was assessed by an MTT assay in LeBTG1 and LeEmpty cells. Flow cytometric analyses were used to evaluate the effect of BTG1 expression on cell cycle distribution and apoptosis. The migration and invasion potential of LeBTG1 cells was examined by plating cells in Matrigel-coated chambers. The level of BTG1 protein expression was found to be significantly lower in esophageal cancer tissue than normal tissues (P < 0.05). Decreased expression of BTG1 was significantly correlated with lymph node metastasis, clinical stage, and histological grade of patients with esophageal cancer (P < 0.05). Meanwhile, loss of BTG1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function shown that Eca-109 cell-transfected BTG1 had a lower survival fraction, higher percentage of the G0/G1 phases, higher cell apoptosis, significant decrease in migration and invasion, and lower cylin D1, Bcl-2, and MMP-9 protein expression compared with Eca-109 cell-untransfected BTG1 (P < 0.05). Reduced BTG1 expression is associated with increased disease severity, suggesting it is a negative regulator of esophageal cancer and can serve as a prognostic indicator.

EMP1 regulates caspase-9 and VEGFC expression and suppresses prostate cancer cell proliferation and invasion

This study aimed to analyze the expression, clinical significance of f epithelial membrane protejn-1 (EMP-1) in prostate carcinoma, and the biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and Western blot were used to analyze EMP1 protein expression in 76 cases of prostate cancer and 34 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. EMP1 lentiviral vector and empty vector were respectively transfected into prostate cancer PC-3 cell line. Quantitative real-time reverse transcription polymerase chain reaction and Western blot were used to detect the mRNA level and protein of EMP1. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, migration, and invasion assays were also conducted as to the influence of the upregulated expression of EMP1 that might be found on PC-3 cell biological effect. Immunohistochemistry: The level of EMP1 protein expression was found to be significantly lower in prostate cancer tissue than normal tissues (P < 0.05). Western blot: The relative amount of EMP1 protein in prostate cancer tissue was found to be significantly lower than in normal tissues (P < 0.05). The level of EMP1 protein expression was not correlated with age and prostate-specific antigen (PSA) concentration (P > 0.05), but it was correlated with T stages, lymph node metastasis, clinic stage, and Gleason score (P < 0.05). The result of biological function shown that PC-3 cell transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher caspase-9, and lower VEGFC protein expression compared with PC-3 cell untransfected EMP1 (P < 0.05). EMP1 expression decreased in prostate cancer and correlated significantly T stages, lymph node metastasis, clinic stage, and Gleason score, suggesting that EMP1 may play important roles as a negative regulator to prostate cancer PC-3 cell by regulating the expression of regulation of caspase-9 and VEGFC protein.

EMP1 inhibits nasopharyngeal cancer cell growth and metastasis through induction apoptosis and angiogenesis

This study aimed to analyze the expression, clinical significance of epithelial membrane protein-1 (EMP1) in nasopharyngeal carcinoma, and the biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and Western blot were used to analyze the EMP1 protein expression in 75 cases of nasopharyngeal cancer and 31 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. Recombinant lentiviral vector was constructed to overexpress EMP1 and then infect nasopharyngeal cancer CNE2 cell line. Quantitative real-time RT-PCR and Western blot were used to detect the mRNA level and protein of EMP1. MTT assay, cell apoptosis, migration, and invasion assays were also conducted to determine the influence of the upregulated expression of EMP1 that might be found on CNE2 cells' biological effect. Immunohistochemistry and Western blot: The level of EMP1 protein expression was found to be significantly lower in nasopharyngeal cancer tissue than in the normal tissues (P < 0.05). Decreased expression of EMP1 was significantly correlated with T stages, lymph node metastasis, clinic stage, and histological grade of patients with nasopharyngeal cancer (P < 0.05). Meanwhile, the loss of EMP1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function has shown that CNE2 cell-transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher caspase-9, and lower vascular endothelial growth factor C protein expression compared with CNE2 cell-untransfected EMP1 (P < 0.05). EMP1 expression decreased in nasopharyngeal cancer and correlated significantly T stages, lymph node metastasis, clinic stage, histological grade, and poor overall survival, suggesting that EMP1 may play important roles as a negative regulator to nasopharyngeal cancer cell.

Effect of cyclin G2 on proliferative ability of prostate cancer PC-3 cell

This study aimed to analyze the expression, clinical significance of cyclin G2 (CCNG2) in prostate carcinoma, and the biological effect in its cell line by CCNG2 overexpression. Immunohistochemistry and Western blot were used to analyze CCNG2 protein expression in 85 cases of prostate cancer and normal tissues to study the relationship between CCNG2 expression and clinical factors. CCNG2 lentiviral vector and empty vector were, respectively, transfected into prostate cancer PC-3 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the mRNA level and protein of CCNG2. MTT assay and cell cycle were also conducted as to the influence of the upregulated expression of CCNG2 that might be found on PC-3 cells biological effect. The level of CCNG2 protein expression was found to be significantly lower in prostate cancer tissue than normal tissues (P < 0.05). The level of CCNG2 protein expression was not correlated with age, PSA contention, and tumor size (P < 0.05), but it was correlated with lymph node metastasis, clinic stage, and Gleason score (P < 0.05). The result of biological function shown that PC-3 cell transfected CCNG2 had a lower survival fraction, more percentage of the G0/G1 phases, and lower CDK2 protein expression compared with PC-3 cell untransfected CCNG2 (P < 0.05). CCNG2 expression decreased in prostate cancer and correlated significantly with lymph node metastasis, clinic stage, and Gleason score, suggesting that CCNG2 may play important roles as a negative regulator to prostate cancer cell.

Liquid chromatography-tandem mass spectrometry determination of the toxicity and identification of fish species in a suspected tetrodotoxin fish poisoning

Suspected tetrodotoxin (TTX) poisoning was associated with eating unknown fish in April 2009 in Taiwan. After ingestion of the fish, symptoms of the victim included perioral paresthesia, nausea, vomiting, ataxia, weakness of all limbs, respiration failure, and death within several hours. The toxicity in the remaining fish was determined, with the mice exhibiting symptoms of neurotoxin poisoning. The implicated fish and deceased victim tissues were analyzed for TTX by liquid chromatography-tandem mass spectrometry. The urine, bile, cerebrospinal fluid (spinal cord), pleural effusion, and pericardial effusion of the victim contained TTX. In addition, the partial cytochrome b gene of the implicated fish was determined by PCR. The DNA sequence in the partial 465-bp cytochrome b gene identified the implicated fish as Chelonodon patoca (puffer fish). These results indicate that people should avoid eating unknown fish species from fish markets where harvested fish may include toxic species.

Evaluation of the genetic diversity and population structure of Chinese indigenous horse breeds using 27 microsatellite markers

We determined the genetic diversity and evolutionary relationships among 26 Chinese indigenous horse breeds and two introduced horse breeds by genotyping these animals for 27 microsatellite loci. The 26 Chinese horse breeds come from 12 different provinces. Two introduced horse breeds were the Mongolia B Horse from Mongolia and the Thoroughbred Horse from the UK. A total of 330 alleles were detected, and the expected heterozygosity ranged from 0.719 (Elenchuns) to 0.780 (Dali). The mean number of alleles among the horse breeds ranged from 6.74 (Hequ) to 8.81 (Debao). Although there were abundant genetic variations found, the genetic differentiation was low between the Chinese horses, which displayed only 2.4% of the total genetic variance among the different breeds. However, genetic differentiation (pairwise FST) among Chinese horses, although moderate, was still apparent and varied from 0.001 for the Guizou-Luoping pair to 0.064 for the Jingjiang-Elenchuns pair. The genetic differentiation patterns and genetic relationships among Chinese horse breeds were also consistent with their geographical distribution. The Thoroughbred and Mongolia B breeds could be discerned as two distinct breeds, but the Mongolia B horse in particular suffered genetic admixture with Chinese horses. The Chinese breeds could be divided into five major groups, i.e. the south or along the Yangtze river group (Bose, Debao, Wenshan, Lichuan, Jianchang, Guizhou, Luoping, Jinjiang and Dali), the Qinghai-Tibet Plateau group (Chaidamu, Hequ, Datong, Yushu, Tibet Grassland and Tibet Valley), the Northeast of China group (Elenchuns, Jilin and Heihe), the Northwest of China group (Kazakh, Yili and Yanqi) and the Inner Mongolia group (Mongolia A, Sanhe, Xinihe,Wuzhumuqin and Sengeng). This grouping pattern was further supported by principal component analysis and structure analysis.

Recent population changes in HbA(1c) and fasting insulin concentrations among US adults with preserved glucose homeostasis

AIMS/HYPOTHESIS

Although diagnosed type 2 diabetes has increased in the past decade, little is known about accompanying changes in fasting plasma glucose (FPG), HbA(1c) and fasting serum insulin (FI) levels in the non-diabetic population.

METHODS

Using population estimates from National Health and Nutrition Examination Surveys, we compared distribution of FPG, HbA(1c) and FI in non-diabetic US persons who were >or=20 years old in 1999 to 2006 with that in persons of the same age in 1988 to 1994.

RESULTS

Age-, sex- and race-adjusted mean FPG levels between the two study periods did not change, but mean HbA(1c) and FI levels increased (0.10% and 4.8 pmol/l, respectively; p < 0.001 for both). The increased HbA(1c) level was driven largely by an upward shift in the lower end of the HbA(1c) distribution. In contrast, the increased FI level was driven primarily by an upward shift in the middle and higher end of FI distribution, especially among persons aged 20 to 44 years. After adjustments for BMI or waist circumference, the increase in the mean HbA(1c) level was attenuated (0.06%; p < 0.001), whereas the mean FPG level decreased by 0.1 mmol/l (p < 0.001) and the mean FI level no longer demonstrated significant change.

CONCLUSIONS/INTERPRETATION

Despite little change in the distribution of FPG levels, HbA(1c) and FI levels increased in the non-diabetic population in the past decade. The increase in FI levels suggests that levels of insulin resistance were greater among US adults, especially young adults, than in the previous decade.

Inhibitory activity of tea polyphenol and Hanseniaspora uvarum against Botrytis cinerea infections

AIMS

To investigate the effect of tea polyphenol (TP) and Hanseniaspora uvarum alone or in combination against Botrytis cinerea in grapes and to evaluate the possible mechanisms involved.

METHODS AND RESULTS

TP alone was effective in controlling grey mould in grape at all concentrations. TP at 0.5 and 1.0% in combination with H. uvarum (1 x 10(6) CFU ml(-1)) showed a lower infection rate of grey mould. TP at 0.01% or above significantly inhibited the spore germination of B. cinerea. TP at 0.1% showed inhibition ability on mycelium growth of B. cinerea. The addition of TP did not affect the growth of H. uvarum in vitro and significantly increased the population of H. uvarum in vivo.

CONCLUSIONS

TP exhibited an inhibitory effect against B. cinerea and improved the biocontrol efficacy of H. uvarum. The inhibitory effects of spore germination and mycelial growth of B. cinerea and the increased populations of H. uvarum in vivo may be some of the important mechanisms of TP.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggested that TP alone or in combination with biocontrol agents has great potential in the commercial management of postharvest diseases of fruits.

Inhibitory activity of tea polyphenol and Candida ernobii against Diplodia natalensis infections

AIMS

To investigate the effect of tea polyphenol (TP) and Candida ernobii alone or in combination against postharvest disease (Diplodia natalensis) in citrus fruit and to evaluate the possible mechanisms involved.

METHODS AND RESULTS

TP at concentrations of 0.1%, 0.5% and 1.0% alone, or in combination with C. ernobii (1x10(6) CFU ml(-1)), showed a lower infection rate of stem-end rot. TP at the concentration of 0.5% or above significantly inhibited the spore germination of D. natalensis. TP at the concentration of 1.0% showed inhibitary ability on mycelium growth of D. natalensis. The addition of TP did not affect the growth of C. ernobii in vitro and significantly increased the population of C. ernobii in vivo.

CONCLUSIONS

TP exhibited an inhibitory effect against D. natalensis and improved the biocontrol efficacy of C. ernobii. It was direct because of the inhibitory effects of TP on spore germination and mycelial growth of D. natalensis in vitro and indirect because of the increased populations of C. ernobii in vivo.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggested that TP alone or in combination with biocontrol agents has great potential in commercial management of postharvest diseases in fruits.

Intraoperative coagulation was more interfered by HES 200/0.5 than normal saline in off-pump coronary artery bypass surgery

AIM

Rapid fluid administration is often necessary for anesthesiologists to maintain intravascular volume in off-pump coronary artery bypass (OPCAB) with acceptable hematocrits. Postoperative hypocoagulation involving postoperative bleeding and hypercoagulation involving graft patency were focused in previous studies but bleeding and blood transfusion are often peaked during vascular anastomoses during OPCAB. This study is designed to investigate the sequential effects of intraoperative coagulation with normal saline and hydroxyethyl starch (HES) solution by thromboelastography (TEG) and standard coagulation tests (SCT).

METHODS

Twenty adult patients scheduled for OPCAB were enrolled in this study. After anesthetic induction, one group received HES 200/0.5 infusion up to 20 mL/kg and the other received 0.9% normal saline (NS) to maintain central venous pressure (CVP) and pulmonary artery occlusion pressures (PAOP). SCT and TEG were measured at T0 (baseline), T1 (after heparin 150 IU/kg, before vascular anastomoses), T2 (after protamine reversal), and T3 (24 hrs after the surgery) to compare the coagulation status.

RESULTS

Baseline data were comparable in both groups. The number of patient who need blood components is higher in HES group. Dilutional hypocoagulation was shown by a significant prolongation of R time at T1 and T2 but also returned comparable at T3 in both groups. K, a-angle, CI and G remained unchanged in NS group but significantly affected in HES group. A statistically significant interaction between groups and treatments on maximal amplitude (MA) (P<0.01) with more blood loss in HES group 24 hours postoperatively (P=0.05). International Normalized Ratio (INR) increased significantly at T2 and T3 in both groups.

CONCLUSION

A rapid infusion of either normal saline or HES solution to maintain intraoperative intravascular volume induce a significant diluted hypocoagulation during OPCAB. The use of HES solution has a prolonged dilutional hypocoagulation and a significant decrease of MA by specific platelet inhibition effects and more transfusion of blood components. All the above changes were not shown in standard coagulation tests.

Bilateral Video-Assisted Thoracoscopic Thymectomy vs. Extended Transsternal Thymectomy in Myasthenia Gravis: A Prospective Study

The optimal approach to thymectomy remains controversial. This study is designed to prospectively compare the results between bilateral video-assisted thoracoscopic thymectomy (BVTx) and extended transsternal thymectomy (ETTx) in patients with myasthenia gravis (MG) without thymoma. Fifteen patients who had undergone BVTx and 16 patients who had undergone ETTx were compared for age, gender, severity of disease, preoperative duration of disease, operative time, intraoperative blood loss, postoperative complications, hospital stay, duration of chest tube drainage, thymic histopathology, pain perception by visual analog scale (VAS), remission and improvement rate, period of follow-up, and activities of daily living (ADL). Fisher's exact test, t test and paired t test were used for statistical analysis. BVTx had longer operative time and less intraoperative blood loss than that of the ETTx. Their remission rates and their degree of postoperative ADL improvement were not significantly different. However, the lowering of VAS was significantly greater in the sternotomy group at 3 months. All other parameters were not significantly different. No mortality was noted in the series. We consider BVTx as an effective alternative procedure to the transsternal approach for patients with nonthymomatous MG. As more and more people care about cosmetics, BVTx could become the future trend.

Broadband and omnidirectional antireflection employing disordered GaN nanopillars

Disordered GaN nanopillars of three different heights: 300, 550, and 720 nm are fabricated, and demonstrate broad angular and spectral antireflective characteristics, up to an incident angle of 60? and for the wavelength range of lambda=300-1800 nm. An algorithm based on a rigorous coupled-wave analysis (RCWA) method is developed to investigate the correlations between the reflective characteristics and the structural properties of the nanopillars. The broadband and omnidirectional antireflection arises mainly from the refractive-index gradient provided by nanopillars. Calculations show excellent agreement with the measured reflectivities for both s- and p- polarizations.

Longitudinal changes in BMI and in an index estimating excess lipids among white and black adults in the United States

BACKGROUND

Adult obesity prevalence is influenced by rates of weight gain or loss among individual persons, but few studies have measured individual weight change in large populations. Changes in weight may not coincide with changes in the lipid accumulation product (LAP), a continuous index derived from waist circumference and triglycerides concentration for estimating excess lipids.

DESIGN AND MEASUREMENTS

Descriptive report of longitudinal changes from US studies that included body mass index (BMI, kg/m(2)) and LAP.

SUBJECTS

A total of 16 763 white and black adults studied between 1989 and 1996 in three observational cohorts (Coronary Artery Risk Development in Young Adults, Atherosclerosis Risk in Communities Study and Cardiovascular Health Study).

RESULTS

The means of individual annual changes in BMI were positive for young adults, but the mean changes were reduced at older ages (P for linear trend <0.001), becoming negative after 73-83 years old. These mean, individual changes in BMI, specific to sex and age, were approximately 0.1 U/year greater than those reported from previous, representative, longitudinal measurements collected in the United States between 1971 and 1984. Mean, individual annual changes in LAP were strongly positive before middle age. For men, the annual LAP changes were reduced at older ages (P linear trend <0.05). For women, they were greater at older ages (white women, P<0.001) or remained unchanged (black women, P>0.3). With increasing age, there was a greater proportion of persons whose positive LAP change was accompanied by simultaneous BMI change that was negative or zero.

CONCLUSIONS

These longitudinal observations made during 1989-1996 suggest greater annual changes in BMI compared to an adult cohort studied during 1971-1984. As estimated by LAP, adults of all ages tended to accumulate excess lipids, including circumstances in which they lost weight.

Interaction between cigarette, alcohol and betel nut use on esophageal cancer risk in Taiwan

OBJECTIVE

In 2003 esophageal cancer was the sixth leading cause of death among men in Taiwan, but it is the fastest increasing (70%) alimentary tract cancer. The aim of this study was to investigate the impact of different habits of betel nut chewing on esophageal squamous cell carcinoma (SCC) and its interaction with cigarette use and alcohol consumption.

MATERIALS AND METHODS

All 165 cases were pathologically proven esophageal SCC patients (all male, mean age = 56.0, range = 35-92 years) diagnosed by biopsy during gastroendoscopic examinations. The control group comprised 255 subjects (all male, mean age = 54.8, range = 40-92 years) selected from patients who had visited the Otolaryngology Outpatient or Inpatient Department of KMUH owing to a benign lesion over this field. All were interviewed to collect demographic and substance use information by a trained interviewer using a standardized questionnaire.

RESULTS

Smoking (aOR = 5.4, 95% CI = 2.4-12.9, PAR = 72%), alcoholic beverage drinking (aOR = 17.6, 95% CI = 9.3-35.2, PAR = 76%) and low education level are independent risk factors for esophageal cancer. Although betel nut chewers only had a borderline significant higher risk than nonchewers (aOR = 1.7; 95% CI = 0.8-3.1), those who chewed with a piece of betel inflorescence (aOR = 4.2, 95% CI = 1.4-16.0) and swallow betel-quid juice (aOR = 3.3, 95% CI = 1.3-9.3) had a significant higher risk. Significant dose-response effects were found in daily quantity of drinking and smoking. There is a synergistic effect of these three substances on the development of esophageal cancer.

CONCLUSION

Betel nut chewing plays a relevant role in the development of esophageal SCC but adds to the carcinogenetic effect of smoking and alcohol drinking. Direct mucosal contact of betel juice may contribute to its carcinogenesis.

The Inhibitory Effect of Altered Collagen II Peptide on HLA-DRB1-Restricted T-Cell Activation

It has been known that rheumatoid arthritis (RA)-associated antigenic peptides CII263-272 are coupled with human leucocyte antigen (HLA)-DRB1 and recognized by T-cell receptor (TCR), which in turn induced T-cell proliferation and pathogenesis of RA. Non-T-cell-stimulating type II collagen (CII) peptides might be generated by removing the amino acids responsible for TCR contact and keeping the HLA-DR-binding residues intact. In this study, a panel of altered CII peptides (APs) with consecutive or single substitutions of the TCR-contacting residues were synthesized. Through peptide binding and T-cell activation assays, we demonstrated that altered CII263-272 peptides with substitution of the TCR-contacting residues did not or barely induced T-cell activation; one of the best non-T-cell-stimulating peptide AP268-270 inhibited the binding of wild-type CII263-272 to HLA-DR1 and T-cell activation triggered by wild-type CII263-272 and HA306-318 in a dose-response manner. These data suggest that removal of the TCR-contacting residues of CII263-272 leads to HLA-DRB1 binding and low T-cell-stimulating peptides, which could potentially inhibit the T-cell response induced by HLA-DRB1-binding antigenic peptides.

Targeted cybridization in citrus: transfer of Satsuma cytoplasm to seedy cultivars for potential seedlessness

CMS (cytoplasmic male sterility) can be controlled by the mitochondrion genome in higher plants, including Satsuma mandarin. Somatic fusion experiments in citrus combining embryogenic callus protoplasts of one parent with leaf protoplasts of a second parent often produce cybrid plants of the leaf parent, a phenomenon occurring most often with interspecific fusion combinations. In an attempt to practically exploit this cybridization phenomenon, we conducted somatic fusion experiments combining embryogenic suspension-derived protoplasts of Satsuma mandarin, Citrus unshiu Marc. cv. Guoqing No. 1 (G1), a male-sterile cultivar, with leaf protoplasts of other seedy types--Hirado Buntan Pink pummelo (HBP) [Citrus grandis (L.) Osbeck], Sunburst mandarin (C. reticulata Blanco), Orie Lee hybrid (C. reticulata cv. Clementine x Murcott tangor), and Murcott tangor [C. reticulata x C. sinensis (L.) Osbeck], respectively--in an attempt to generate seedless cybrids by the targeted transfer of CMS. The genetic identities of regenerated plants from all four parental combinations were determined by flow cytometry, SSR, CAPS (or PCR-RFLP), RFLP, and chloroplast-SSR analyses. Regenerated plants from the first three parental combinations were diploids, and the cybrid nature of G1 + HBP with the mitochondrion genome from G1 and the chloroplast genome from HBP was confirmed, whereas the cybrid nature of the remaining two combinations was difficult to confirm because of the close phylogenetic relatedness of both fusion parents, as expected. Plants from G1 + Murcott were confirmed as tetraploid somatic hybrids. This is the first report of targeted citrus cybrid production by symmetric fusion with male-sterile Satsuma as the callus parent and other seedy cultivars as the leaf parents.

Effects of physical activity on exercise tests and respiratory function

BACKGROUND

Exercise is an important component of pulmonary rehabilitation for patients with chronic lung disease.

OBJECTIVE

To explore the role of physical activity in maintaining cardiac and respiratory function in healthy people.

METHODS

Cardiorespiratory fitness was measured by a maximal treadmill test (MTT), and respiratory function was tested by spirometry. The cross sectional study included data from 24 536 healthy persons who were examined at the Cooper Clinic between 1971 and 1995; the longitudinal study included data from 5707 healthy persons who had an initial visit between 1971 and 1995 and a subsequent visit during the next five years. All participants were aged 25-55 years and completed a cardiorespiratory test and a medical questionnaire.

RESULTS

In the cross sectional study, after controlling for covariates, being active and not being a recent smoker were associated with better cardiorespiratory fitness and respiratory function in both men and women. In the follow up study, persons who remained or became active had better MTT than persons who remained or became sedentary. Men who remained active had higher forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC) than the other groups. Smoking was related to lower cardiorespiratory fitness and respiratory function.

CONCLUSIONS

Physical activity and non-smoking or smoking cessation is associated with maintenance of cardiorespiratory fitness. Change in physical activity habits is associated with change in cardiorespiratory fitness, but respiratory function contributed little to this association during a five year follow up.

Oxidative stress in bilateral total knee replacement, under ischaemic tourniquet

Free radicals, such as reactive oxygen species (ROS) which are released abruptly after deflation of an ischaemic tourniquet, cause reperfusion injuries. Ischaemic precondition (IPC), however, can reduce the injury. In clinical practice, the sequential application and release of tourniquets is often used in bilateral total knee replacement (TKR) to obtain a clearer operative field, but the effects on the production of free radicals and lipid peroxidation have not been studied. In this study, we have observed the production of free radicals and the subsequent lipid peroxidation in bilateral TKR with sequential application of a tourniquet to examine the effect of IPC. Patients undergoing elective TKR under intrathecal anaesthesia were studied. Blood samples were obtained after spinal anaesthesia, one minute before and five and 20 minutes after release of each tourniquet. We used the lucigenin chemiluminescence analysis and the phosphatidylcholine hydroperoxide (PCOOH) assay to measure the production of ROS and lipid peroxidation. Our results showed that production of ROS significantly increased at five and 20 minutes after release of the first tourniquet and at five minutes after release of the second tourniquet, but returned to normal at 20 minutes after the second reperfusion. The peak production of ROS was at 20 minutes after the first reperfusion; lipid peroxidation did not change significantly. We conclude that in spite of significant production of ROS after the release of tourniquet, the IPC phenomenon occurs during bilateral TKR with sequential application of a tourniquet.

Molecular characterization of cytoplasmic and nuclear genomes in phenotypically abnormal Valencia orange (Citrus sinensis) + Meiwa kumquat (Fortunella crassifolia) intergeneric somatic hybrids

Organelle DNA inheritance of four 10-year-old somatic hybrid trees between Valencia orange [Citrus sinensis (L.) Osbeck] and Meiwa kumquat (Fortunella crassifolia Swingle) was analyzed by cleaved amplified polymorphic sequence (CAPS) and restriction fragment length polymorphisms (RFLPs). Five chloroplast (cp) and three mitochondrial (mt) universal primer pairs were amplified, but no polymorphisms were detected. When the polymerase chain reaction products were digested by 15 restriction enzymes, four polymorphic cpDNA-CAPS and two mtDNA-CAPS markers were found. Both the cpDNA and mtDNA in the somatic hybrids were derived from Valencia orange (the embryogenic suspension parent). Genomic DNA of the somatic hybrids and corresponding parents was digested by five restriction endonucleases and hybridized with one chloroplast probe (RbcL- RbcL) and nine mitochondrial probes (coxI, coxII, c oxIII, c ob, atpA, tyr, proI, atp6 and atp9). The results indicated that three hybrid plants shared one strong cpDNA band with both parents and that the remaining one plant had two additional novel bands besides the shared band, while their mtDNA was identical to that of Valencia orange plus non-parental bands. When data on the mtDNA banding patterns were combined with observations on phenotypic performance in the field, it was found that the more complex mtDNA banding pattern coincided with increased vigor of the plant. The stability of the organelle genomes was studied by extracting the genomic DNA of one hybrid plant at monthly intervals for 1 year and then analyzing it using RFLPs. Before the dieback of the shoots, two fragments of the mtDNA were lost while the cpDNAs remained stable. Ploidy analysis by flow cytometry showed that all of the hybrids were stable tetraploids. Four simple sequence repeat primer pairs were applied to detect microsatellite alleles of the four hybrid plants, both parents and the 12 DNA samples from one plant. The results showed that all hybrids had biparental bands uniformly, which indicated that they had the same nuclear background. These results suggest that the mtDNA pattern is correlated with the phenotypic abnormality of Valencia and kumquat somatic hybrid plants and that nuclear-cytoplasm incompatibility may be the cause of dieback.

Occupational exposure to wood, formaldehyde, and solvents and risk of nasopharyngeal carcinoma

Our objective was to evaluate the link between occupational exposures to wood dust, formaldehyde, and solvents and the development of nasopharyngeal carcinoma (NPC). A case-control study was conducted among 375 newly diagnosed cases of NPC in Taipei, Taiwan, and 325 community controls matched to cases on sex, age, and geographical residence (99 and 87% response rates, respectively). Most cases (>90%) were diagnosed with WHO Types 2 or 3 (nonkeratinizing and undifferentiated carcinomas), whereas the remaining cases were diagnosed with WHO Type 1 (squamous cell carcinomas). A complete occupational history was obtained via a personal interview and blindly assessed by an industrial hygienist for intensity and probability of exposure to wood dust, formaldehyde, and solvents. Information on socio-demographic characteristics, cigarette smoking, dietary consumption of nitrosamines, and other potential confounding factors was obtained via a personal interview. Blood specimens were tested for human leukocyte antigen class I/II genotypes, polymorphisms in cytochrome P450 2E1 genotype, and various anti-EBV antibodies known to be associated with NPC. Analysis was performed using logistic regression; relative risk (RR) estimates and 95% confidence intervals (CI) were calculated. Individuals exposed to wood dust had an adjusted RR of 1.7 (95% CI = 1.0-3.0). Those exposed to wood dust for >10 years had an adjusted RR of 2.4 (95% CI = 1.1-5.0; p(trend) = 0.02). Risk was strongest for those first exposed before the age of 25 years and those seropositive to EBV. Individuals exposed to formaldehyde were at a more modest and nonsignificant increased risk of NPC (RR = 1.4; 95% CI = 0.93-2.2). Those exposed to formaldehyde for >10 years had an adjusted RR of 1.6 (95% CI = 0.91-2.9). The association between formaldehyde and NPC was stronger in analyses restricted to EBV seropositive individuals (RR = 2.7; 95% CI = 1.2-5.9). However, no dose response was observed with increasing duration or cumulative use. No association was observed between solvent exposure and NPC (RR = 1.2; 95% CI = 0.86-1.7). Occupational exposure to wood dust is likely to be involved in the development of NPC, a finding that is consistent with the known link between wood exposure and nasal adenocarcinomas. Formaldehyde exposure is less clearly linked to NPC, whereas exposure to solvents is unlikely to be involved in NPC pathogenesis.

Bedside pericardiocentesis under the guidance of transesophageal echocardiography in a 13-month-old boy

Pericardial effusion is a common sequel to cardiac surgery. Urgent pericardiocentesis is required in the case of cardiac tamponade. In adult patients, most pericardiocentesis is accomplished using transthoracic echocardiographic imaging. However, transthoracic echocardiographic imaging may interfere with the procedure field in children. We report the case of a 13-month-old boy who developed cardiac tamponade resulting in heart failure after surgical repair of tetralogy of Fallot. Urgent pericardiocentesis was safely performed at the bedside under transesophageal echocardiographic guidance. Transesophageal echocardiographic monitoring during pericardiocentesis in children has the advantages of better imaging of pericardial effusion without procedure-field interference.