Molecular Dynamics Study on Permeability of Gas Molecules through Amorphous PPX Polymers

Amorphous poly-para-xylylene (PPX) polymers were constructed using molecular mechanics (MM) and NVT+NPT-annealing methods. They provide the cut-off free volumes to absorb and transfer gas molecules. The corresponding sorption and diffusion properties were determined via Grand Canonical Monte Carlo (GCMC), NVT-Molecular Dynamics (MD) and cluster analysis methods. The results showed that temperature and pressure influence the sorption properties of gases obviously, but not to the diffusion coefficients of gases. Analyzing on the mean square displacement (MSD) data, this work finds that gases walk randomly through amorphous PPX polymers. The relative cluster permeability approaches to the experimental data.

Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs

The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.

Trends in seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus among patients seeking care in China

We determined seroprevalence of antibodies to pandemic influenza H1N1 (2009) virus in outpatients in China from December 2009 to March 2010. Serum antibody titers were determined by a hemagglutination-inhibition (HI) assay using the seroprevalence data for 2006-2008 (1.2%) as baseline. The overall seroprevalence was 7.6%, 18.6%, 20.5%, and 20.0% in December 2009, January 2010, February 2010, and March 2010, respectively. In comparison of monthly data, the seroprevalence values for the first three months exhibited statistically significant differences. As for the age-specific seroprevalence, the individuals aged demic virus.

Fasting capillary blood glucose: an appropriate measurement in screening for diabetes and pre-diabetes in low-resource rural settings

OBJECTIVE

To evaluate the efficiency of fasting capillary blood glucose (FCG) measurement as compared with fasting venous plasma glucose (FPG) measurement in screening diabetes and pre-diabetes in low-resource rural settings.

SUBJECTS AND METHODS

In 2010, 993 participants were randomly selected from 9 villages in Yunnan province using cluster sampling method. Samples for FCG and FPG test were obtained after demographics and physical examination. The oral glucose tolerance test was performed in parallel as gold standard for diagnosis. Diagnostic capacities of the FCG measurement in predicting undiagnosed diabetes and pre-diabetes were assessed. The performance of FCG and FPG tests was compared.

RESULTS

Fifty-seven individuals with undiagnosed diabetes and 145 subjects with pre-diabetes were detected. The concordance between FCG and FPG levels was high (r = 0.75, p < 0.001). The area under the curve (AUC) for FCG test in predicting diabetes was 0.88 [95% confidence interval (CI) 0.82-0.93] with the optimal cutoff value of 5.65 mmol/l, sensitivity of 84.2%, and specificity of 79.3%. The corresponding values in FPG tests were 0.92 (95% CI 0.88-0.97) (AUC), 6.51 mmol/l (optimal cutoff point), 82.5% (sensitivity) and 98.3% (specificity), respectively. No significant difference was found in the AUC for the two screening strategies.

CONCLUSION

FCG measurement is considered to be a convenient, practicable screening method in low-resource rural communities with acceptable test properties.

WE-D-213AB-03: Preparing for the ABR Diagnostic Medical Physics Board Exams - Oral Exam

Part III (oral exam) is the final part of ABR board exam for Diagnostic Medical Physics. In this exam, each of five oral examiners questions the candidate in each of five question categories. Oral exam has unique challenges to the candidate compared with the written exams. The candidate is expected to have not only adequate knowledge on each aspect of imaging physics, but also extensive clinical experience on different imaging modalities. The candidate needs to demonstrate her/his knowledge and clinical experience by correctly and effectively answering specific questions during the exam. Depending on the response of the candidate to original question, different follow-up questions are usually asked. Therefore, the interaction with examiners plays a critical role in the oral exam. The format and question categories of the oral exam in diagnostic medical physics will be reviewed. Study materials and effective study methods will be discussed. Practical tips on answering questions and interactions with examiners during the oral exam will also be shared.

LEARNING OBJECTIVES

1. Understand the format and scope of oral exam. 2. Develop an effective method for exam preparation. 3. Learn how to effectively answer questions and interact with examiners during the exam.

Response to the first wave of pandemic (H1N1) 2009: experiences and lessons learnt from China

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.

Posterior lumbar interbody fusion using spinous process and laminae

Posterior lumbar interbody fusion (PLIF) is indicated for many patients with pain and/or instability of the lumbar spine. We performed 36 PLIF procedures using the patient's lumbar spinous process and laminae, which were inserted as a bone graft between two vertebral bodies without using a cage. The mean lumbar lordosis and mean disc height to vertebral body ratio were restored and preserved after surgery. There were no serious complications. These results suggest that this procedure is safe and effective.

A systematic-analysis of predicted miR-21 targets identifies a signature for lung cancer

INTRODUCTION

The well-known oncomiR-miR-21 was previously reported oncogenic activity in lung cancer. We sought to determine the expression of all predicted target genes of miR-21 and their potential function, pathways and networks, which are involved in the biological behavior of lung cancer.

METHODS

After a systematic review of English language studies of lung cancer-related molecules were pooled; genes were classified in three functional groups by gene ontology (GO) analysis. The key molecules were indentified by establishing lung cancer related networks and pathways. MiR-21 targets were predicted by computational method, followed by screening for matched gene symbols in NCBI human sequences and GO, pathway and network analysis. MiR-21 targets and their network, which are involved in the malignant mechanisms of lung cancer, were obtained by the final integrative analysis.

RESULT

We indentified the potential functions, pathways and networks of lung cancer relating molecules and miR-21 targets respectively in the initial analysis. In the final integrative analysis of lung cancer related miR-21-targets analysis, 24 hub genes were identified by overlap calculation, suggesting that miR-21 may play an important role in the development and progression of lung cancer through JAK/STAT signal pathway, MAPK signaling pathway, Wnt signaling pathway, cell cycle, PPAR signaling pathway, apoptosis pathway and other pathways.

CONCLUSION

Our data may help researchers to predict the molecular mechanisms of miR-21 in the development and progression of lung cancer comprehensively. Moreover, the present data indicate that miR-21-targets may be a series of promising candidates as biomarkers for lung cancer.

Enhanced antitumor activity of epirubicin combined with cerulenin in osteosarcoma

Osteosarcoma (OS) is the most common primary malignant neoplasm in children and adolescents. Epirubicin is one of the chemotherapeutic agents currently used for the treatment of OS; however, the efficacy of chemotherapy is hampered by the acquired drug resistance of OS. Cerulenin, an inhibitor of fatty acid synthase, has been defined as a candidate tumor suppressor. In this study, we explored the combined effect of cerulenin plus the chemotherapy drug, epirubicin, on human OS U2-OS cells in vitro and in vivo. We demonstrated that cerulenin plus epirubicin induced synergistic growth inhibition and enhanced apoptosis in U2-OS cells. We also demonstrated that cerulenin plus epirubicin synergistically suppressed tumor growth in subcutaneously xenografted U2-OS cells in athymic nude mice. Our results indicate that cerulenin enhances the anti-OS effects of epirubicin in vivo and in vitro.

The glutaminergic, GABAergic, dopaminergic but not cholinergic neurons are susceptible to anaesthesia-induced cell death in the rat developing brain

Neuronal cell death induced by anaesthetics in the developing brain was evident in previous pre-clinical studies. However, the neuronal cell types involved in anaesthesia-induced neuronal cell death remains elusive. The aim of this study was to investigate glutamatergic, GABAergic, cholinergic and dopaminergic neuronal cell apoptosis induced by anaesthetic exposure in specific brain regions in rats. Separate cohorts of 7-day-old Sprague Dawley (SD) rat pups were randomly assigned to two groups: Naive and anaesthetics alone (70% nitrous oxide and 0.75% isoflurane exposure for 6 h). The brains were sectioned and the slices that contained the basal forebrain, substantia nigra, cornu ammonis area 1 (CA1) subarea of hippocampus or cingulate cortex were selected and subsequently subjected to double-labelled fluorescent immunohistochemistry for choline acetyltransferase, dopamine, vesicular glutamate transporter 1 (vGLUT1) or glutamic acid decarboxylase 67 (GAD67) together with caspase 3, respectively. Compared to the naive control, anaesthetic exposure significantly increased the number of caspase-3 positive cells in the CA1 subarea of hippocampus, cingulate cortex, and substantia nigra, but not in the basal forebrain. 54% and 14% of apoptotic cells in the CA1 subarea of hippocampus were GABAergic and glutamatergic neurons respectively. In the cingulate cortex, 30% and 37% of apoptotic cells were GABAergic and glutamatergic neurons respectively. In the substantia nigra, 22% of apoptotic cells were dopaminergic neurons. Our data suggests, anaesthetic exposure significantly increases neuroapoptosis of glutamatergic, GABAergic and dopaminergic neurons in the developing brain but not that of the cholinergic neurons in the basal forebrain.

[Investigation of allergens in 3,504 children with allergic diseases]

OBJECTIVE

To investigate the allergens of various allergic diseases in children.

METHODS

Serum levels of Fx5E, Phadiatop and specific IgE were measured by the UniCAP100 System in 3 504 children with allergic diseases.

RESULTS

The positive rate of aeroallergens was obviously higher than that of food allergens in children with allergic rhinitis, allergic conjunctivitis, asthma and papular urticaria. In contrast, the positive rate of food allergens was obviously higher than that of aeroallergens in children with Henoch-Schonlein purpura and digestive diseases. The serum specific IgE level of aeroallergens was higher than that of food allergens. The dust and mite specific IgE levels reached to grade 6, while the food allergen specific IgE levels were lower than grade 3.

CONCLUSIONS

Aaeroallergens or food allergens vary remarkably in different allergic diseases in children. The level of specific IgE of aeroallergens is higher than that of food allergens.

[Laparoscopic transhiatal extended gastrectomy for type II, III esophagogastric junction cancer: a preliminary report of 55 cases]

OBJECTIVE

To explore the feasibility and safety of laparoscopic extended gastrectomy through the transhiatal approach in patients with esophagogastric junction cancer.

METHODS

From Feb 2008 to May 2010, 55 cases with Siewert type II or III esophagogastric junction cancer underwent laparoscopic transhiatal extended gastrectomy at the West China hospital. Clinical data were analyzed retrospectively.

RESULTS

Esophagogastric junction cancer was Siewert type II in 36 patients and Siewert type III in 19. Thirty-five cases underwent proximal gastrectomy, 20 total gastrectomy. There were 53 D2 lymph node excisions and 2 palliative resections. Fifty patients underwent laparoscopic extended gastrectomy successfully, with 5 converted to open operations. A safe anastomosis between inferior pulmonary vein and pulmonary hilum was achieved in the majority of patients. The mean operative time was(236.2±35.5) min and the mean estimated blood loss was(60.6±33.9) ml. There were no postoperative mortalities or anastomotic leakage/stenosis. No reoperations were required. Pleural laceration occurred in 11 cases during operation, of whom 10 were repaired intraoperatively and one was managed with drainage postoperatively. There were 3 patients developed pulmonary infection and one wound infection. Postoperative recovery was uneventful in other patients.

CONCLUSION

Laparoscopic transhiatal extended gastrectomy is feasible and safe for patients with esophagogastric junction cancer.

[Detection of serum specific IgE in 437 children with allergic disease]

OBJECTIVE

To investigate the distribution of allergens in children with allergic disease in Changsha.

METHODS

Total IgE and specific IgE against some allergens were examined by the AllergyScreen system in the sera of 437 children from Changsha with allergic disease.

RESULTS

The positive rates of total IgE and special IgE were 68.9% and 69.1% respectively. Dermatophagoides farina, beef, mutton, milk and fur of cats and dogs were found as common allergens. The IgE positive rate against dermatophagoides farina was the highest in children with allergic rhinitis (86.0%), followed by in those with atopic dermatitis (41.2%), eczema (27.6%) and urticaria (20.0%). Serum IgE was positive against the fur of cats and dogs in 23.5% of children with atopic dermatitis and in 18.1% of children with eczema. The IgE positive rate was lower in children with urticaria and allergic rhinitis (10.0% and 8.7% respectively). IgE positive rates against milk, beef and mutton were high in the above four allergic diseases (range: 14.0%-24.0%), but no significant differences were observed for the IgE positive rate among the four allergic diseases. The IgE positive rate to inhalant allergens in children at ages of less than 3 years was markedly higher than that in children at ages of more than 3 years (p<0.01).

CONCLUSIONS

Allergic diseases are mainly mediated by allergens. Allergens, especially dermatophagoides farina, fur of cats and dogs, beef, mutton and milk, play an important role in childhood allergic diseases in Changsha.

Occurrence and prognostic value of circumferential resection margin involvement for patients with rectal cancer

BACKGROUND AND AIM

Total mesorectal excision (TME) was advocated owning to the reduction in local failure, while deficiency in pathologic details limited monitoring of surgical quality assurance. Here, we aimed to examine circumferential resection margin (CRM) by large tissue slice, discussing its rule in occurrence and relationship with prognosis, thus providing proof for the adoption of TME principles and the application of adjuvant therapy.

MATERIALS AND METHODS

Specimens of 106 patients with rectal cancer, who underwent potentially curative resection from December 2001 to September 2002, were examined. Follow-up data were collected.

RESULTS

Altogether, 2,068 mesorectal nodes were examined with 272 involved by tumor. CRM involvement (CRMI) was examined in 20 specimens. In these 20 cases, seven, nine, and four were caused by tumor infiltration, lymph node metastasis, and both, respectively. Occurrence of CRMI was more common for lower-located cancers while also statistically related to tumor differentiation, infiltration, and lymph node metastasis. The difference in local recurrence rate, general recurrence rate, disease-free survival rate, and overall survival rate between the group with CRMI and the group without were all proven to be significant.

CONCLUSIONS

Detailed pathologic examination, including status of CRM, is advocated since it provides accurate prognostic information. Surgeons could maximize the probability of cure by following the principle of TME. Preoperative adjuvant therapy was essential for advanced staged and lower-located lesions, which implied likelihood of CRMI.

Normal pregnancy resulting from a non-pronuclear oocyte at the time of examination for fertilization

PURPOSE

To report the case of a patient undergoing in vitro fertilization (IVF) in which a non-pronuclear (0PN) oocyte resulted in a normal pregnancy.

METHODS

A 36-year-old woman underwent an IVF-embryo transfer treatment cycle.

RESULTS

Four oocytes were retrieved for insemination by IVF. Examination for fertilization revealed two polypronuclearpolygynic and two non-pronuclear oocytes. The non-pronuclear oocytes were observed further for development. One embryo developed from the non-pronuclear cohort and was transferred at the 8-cell stage on day 3. Subsequently, a pregnancy developed, and resulted in the delivery of a healthy term infant.

CONCLUSIONS

Non-pronuclear oocytes may represent a source of developmentally competent embryos, and further observation of this cohort should be considered, particularly in situations involving a low yield of oocytes at retrieval.

Sequential evaluation of a medical diagnostic test with binary outcomes

In a study evaluating a medical diagnostic test, human samples are valuable and often costly, therefore prime concerns require termination of the study if the test is evidently inefficient (or efficient) in diagnosis of diseases in order to keep the number of samples as low as possible. In this paper, we propose sequential designs to evaluate the sensitivity and specificity of a diagnostic test. One method allows early stopping if the sensitivity and specificity of a new medical test are both within the level of tolerance. Another method terminates the study if either the sensitivity or the specificity is below the minimally acceptable level. The latter method minimizes the expected sample size when the test does not meet expectations on performance, and illustrates substantial advantage of having smaller expected sample sizes in various two-stage designs compared to the sample sizes of single-stage designs when a diagnostic test is not promising.

Shaping ability of progressive versus constant taper instruments in curved root canals of extracted teeth

AIM

To compare the shaping ability of progressive versus constant taper shaft instruments in curved root canals of extracted human teeth.

METHODOLOGY

A total of 40 root canals of mandibular molars with curvatures ranging between 20 degrees and 40 degrees were divided into two groups of 20 canals each and embedded in a muffle system. The root canals sectioned horizontally at three levels before preparation and then remounted into the mould. All root canals were prepared with ProTaper (progressive taper) or Hero Shaper (constant taper) instruments. Pre- and post-instrumentation radiographs and cross-sectional images were obtained. The parameters evaluated were: working safety (instrument failure, apical blockage and loss of working length) and shaping ability (straightening, cross-sectional area, transportation and centring ability). The data were analysed statistically using Student's t-test.

RESULTS

No instrument fractured during preparation. One Hero Shaper instrument permanently deformed. Both instrument systems maintained working length well. The canals prepared with Hero Shaper instruments were straightened to a lesser degree (P < 0.05). ProTaper instruments removed more dentine in the coronal and the middle sections of the canals. Canals prepared with Hero Shaper instruments had less transportation (P < 0.01) and better centring ability (P < 0.05) in the apical section.

CONCLUSIONS

Both instrument systems were safe to use and maintained working length well. The canals prepared with Hero Shaper had less transportation and were better centred in the apical region, possibly because their smaller taper reduced instrument stiffness.

Effect of genetic variation in the organic cation transporter 1, OCT1, on metformin pharmacokinetics

The goal of this study was to determine the effects of genetic variation in the organic cation transporter 1, OCT1, on the pharmacokinetics of the antidiabetic drug, metformin. Twenty healthy volunteers with known OCT1 genotype agreed to participate in the study. Each subject received two oral doses of metformin followed by collection of blood and urine samples. OCT1 genotypes had a significant (P<0.05) effect on metformin pharmacokinetics, with a higher area under the plasma concentration-time curve (AUC), higher maximal plasma concentration (Cmax), and lower oral volume of distribution (V/F) in the individuals carrying a reduced function OCT1 allele (R61C, G401S, 420del, or G465R). The effect of OCT1 on metformin pharmacokinetics in mice was less than in humans possibly reflecting species differences in hepatic expression level of the transporter. Our studies suggest that OCT1 genotype is a determinant of metformin pharmacokinetics.

Increasing tripartite cooperation of ER-alpha, c-Src, and IGF-1R plays an important role in tamoxifen resistance

11037

Background: Acquired resistance to tamoxifen is a serious therapeutic problem that limits its clinical benefit. The precise mechanisms for acquired tamoxifen resistance, however, are still not fully understood. Our prior studies suggest that enhancement interaction between growth factors and ERa was associated with development of tamoxifen resistance. Cross-talk between growth factor receptors and estrogen receptor alpha (ERa) makes this problem more complicated. We hypothesized that some other proteins may be involved in this association between two kinds receptors in the development of TAM resistance. Methods: To test our hypothesis, MCF-7 breast cancer cells were continuously treated with TAM (10–7 M) until the cells resist to tamoxifen treatment, which were named as tamoxifen resistant cells (TAM-R). Results: TAM-R cells were more sensitive to E2 and IGF-1 stimulation to express higher level phospho-MAPK than that of control cells. Inhibitory effect of AG1024 on TAM-R cells was about as 2 folds as many as that of control cells. MAPK inhibitor caused dramatic inhibition of growth of TAM-R cells. It was interestingly found that ERa translocated from nucleus to cytosol and an increased amount of ERa was co-immunoprecipitated with IGF-1R from TAM-R cells even though there was no change in the levels of these receptors compared to the control cells. c-Src was an important adapter protein between these two receptors, which increasingly combined with both IGF-1R and ERa in TAM-R cells. Pure antiestrogen ICI, AG1024/IGF-1R SiRNA, and Src family inhibitor PP2 could inhibit the interaction between IGF-1R and ERa. However, only PP2 could completely inhibit ERa translocate from nucleus to cytosol and cytoplasm membrane. Conclusions: Our results suggested that IGF-1R/MAPK signaling pathway was very important for TAM-R cells to develop resistance. c- Src was an critical elements to form a ternary complex with IGF-1R and ERa. This may be one mechanism responsible for tamoxifen resistance in breast cancer cells.

No significant financial relationships to disclose.

[Impact of mesorectal involvement on the outcome of patients with rectal cancer]

OBJECTIVE

To assess the relationship between the incidence and prognostic significance of mesorectal involvement.

METHODS

328 cases of rectal cancer resected with total or subtotal mesorectal excision in our hospital from Jan. 1997 to Dec. 1998 were followed up and analyzed in this study. The neoplastic foci were identified at the pathologic examination of the mesorectum.

RESULTS

Neoplastic mesorectal metastasis was found in 234 cases (71.3%); node involvement in 59.8% and microscopic foci involvement in 36% of all cases (isolated in 11.6%, microfoci alone without any kind of other mesorectal involvement). Microscopic deposits were found in 10.3% of TNM Stage I tumors, in 18.4% of Stage II and in 45.1% of Stage III cancers. Five-year disease-free survival rate (49.6% vs. 91.4%) were observed in patients with mesorectal involvement, compared with those without deposits.

CONCLUSION

The incidence of neoplastic foci in the mesorectum seem to affect prognosis, even in early staged tumors. The presence of mesorectal foci should be considered an index in modifying the conventional staging of the rectal tumor.

The Biomolecular Interaction Network Database and related tools 2005 update

The Biomolecular Interaction Network Database (BIND) (http://bind.ca) archives biomolecular interaction, reaction, complex and pathway information. Our aim is to curate the details about molecular interactions that arise from published experimental research and to provide this information, as well as tools to enable data analysis, freely to researchers worldwide. BIND data are curated into a comprehensive machine-readable archive of computable information and provides users with methods to discover interactions and molecular mechanisms. BIND has worked to develop new methods for visualization that amplify the underlying annotation of genes and proteins to facilitate the study of molecular interaction networks. BIND has maintained an open database policy since its inception in 1999. Data growth has proceeded at a tremendous rate, approaching over 100 000 records. New services provided include a new BIND Query and Submission interface, a Standard Object Access Protocol service and the Small Molecule Interaction Database (http://smid.blueprint.org) that allows users to determine probable small molecule binding sites of new sequences and examine conserved binding residues.