1,103 research outputs found
Dual fluorescence from aqueous 1-naphthylamine solutions of high pH - Excited-state acidic dissociation of naphthylamine
Dual fluorescence at ca. 447 nm and 545 nm was observed from the aqueous 1-naphthylamine (NA) solutions at pH higher than 13.6. Similar dual fluorescence was also found with sodium 1-naphthylaminoacetate(NAA), but not with N, N-disubstituted 1-aminonaphthalenes such as sodium 1-naphthylaminodiacetate (NADA) and 1-dimethylaminonaphthalene (DMAN). No change in absorption spectra of NA and NAA was observed in this pH region. It was proposed that the dual fluorescence observed with NA and NAA was due to the excited state dissociation of the primary and secondary amines at high pH. From the dual fluorescence intensity ratio pH titration curve, the pK(a)(.)'s of NA and NAA were estimated to be between 14 and 15 which are much lower than the ground state pK(a). The novel approach is such a simple, convenient and frequent analysis technique that it can be widely used in detecting the substitutional derivatives of aminonaphthalene
Determining the role of external beam radiotherapy in unresectable intrahepatic cholangiocarcinoma: a retrospective analysis of 84 patients
<p>Abstract</p> <p>Background</p> <p>Intrahepatic cholangiocarcinoma (ICC) is the second most common type of primary liver cancer. Only few studies have focused on palliative radiotherapy used for patients who weren't suitable for resection by surgery. This study was conducted to investigate the effect of external beam radiotherapy (EBRT) for patients with unresectable ICC.</p> <p>Methods</p> <p>We identified 84 patients with ICC from December 1998 through December 2008 for retrospective analysis. Thirty-five of 84 patients received EBRT therapy five times a week (median dose, 50 Gy; dose range, 30-60 Gy, in fractions of 1.8-2.0 Gy daily; EBRT group); the remaining 49 patients comprised the non-EBRT group. Tumor response, jaundice relief, and survival rates were compared by Kaplan-Meier analysis. Patient records were reviewed and compared using Cox proportional hazard analysis to determine factors that affect survival time in ICC.</p> <p>Results</p> <p>After EBRT, complete response (CR) and partial response (PR) of primary tumors were observed in 8.6% and 28.5% of patients, respectively, and CR and PR of lymph node metastases were observed in 20% and 40% of patients. In 19 patients with jaundice, complete and partial relief was observed in 36.8% and 31.6% of patients, respectively. Median survival times were 5.1 months for the non-EBRT group and 9.5 months for the EBRT group (<it>P </it>= 0.003). One-and two-year survival rates for EBRT versus non-EBRT group were 38.5% versus 16.4%, and 9.6% versus 4.9%, respectively. Multivariate analysis revealed that clinical symptoms, larger tumor size, no EBRT, multiple nodules and synchronous lymph node metastases were associated with poorer prognosis.</p> <p>Conclusions</p> <p>EBRT as palliative care appears to improve prognosis and relieve the symptom of jaundice in patients with unresectable ICC.</p
Mild to moderate influenza A(H7N9) infections detected through China’s national influenza-like Illness sentinel surveillance system
Poster Session: News and Views from the H7N9 OutbreakBackground: The “clinical iceberg” phenomenon, where there are usually many more infected cases
than is apparent symptomatically and even less so registered in the clinical setting, is a common
feature of influenza disease. While this is certainly true for interpandemic influenza and the 2009
influenza A(H1N1) pandemic, this appeared to be less substantial for the Dutch A(H7N7) outbreak,
and with A(H5N1) being an acknowledged exception. It remains unknown whether the “iceberg”
applies to the influenza A(H7N9) virus that emerged in early 2013 in China. While the majority of
laboratory-confirmed A(H7N9) cases presented with a severe clinical picture to a hospital, a small
number of laboratory-confirmed cases have been identified through the sentinel influenza-like illness
(ILI) surveillance system nationwide. The objective of our study was to describe the clinical
characteristics of the complete case series of A(H7N9) cases as of May 15, 2013, that were identified
through routine testing by the ILI sentinel surveillance system. Materials and Methods: ILI sentinel
surveillance in China is conducted through a network of 554 hospitals across the country, with the
total number of outpatient and/or emergency department visits and the number of patients fitting the
WHO standard ILI case definition reported weekly online to the China CDC, and 10-15
nasopharyngeal swabs collected from ILI patients each week for routine laboratory testing and
subtyping. All A(H7N9) cases detected through the ILI surveillance system by May 15, 2013, were
identified by cross-referencing the laboratory-confirmed A(H7N9) line list with the routine sentinel ILI
surveillance system. Demographic and epidemiologic data were extracted from field investigation
records, and clinical and laboratory data were obtained from medical chart review. Results: Five
(3.8%) of a total of 130 laboratory-confirmed influenza A(H7N9) cases reported as of May 28, 2013,
were detected through the routine ILI surveillance system. Four (80%) of them were male. Mean age
was 13 (range = 2-26) years and none had any underlying medical condition. Exposure history,
geographic location and timing of symptom onset were otherwise similar to the general cohort of all
laboratory-confirmed cases to date. All patients experienced only mild or moderate disease with an
uneventful course of recovery. Among them three (60%) were managed only as outpatients and all
quickly recovered after 3-5 days, with nasopharyngeal swabs tested positive for A(H7N9) only after
their full recovery. Two patients (40%) were hospitalized for treatment. One was a 4-year-old child
from Shanghai who presented initially as an outpatient with fever and mild rhinorrhea to a routine
sentinel clinic, and was admitted on the next day for oseltamivir treatment after his nasopharyngeal
swab was tested positive for A(H7N9). The other was a 26-year-old man from Jiangsu who presented
initially with fever and productive cough to a sentinel clinic, being given ceftazidime without
improvement. He was admitted 4 days later with radiologic evidence of left-sided pneumonia, and
started on oseltamivir and moxifloxacin. Both remained clinically stable with quick resolution of
symptoms within 10 days. Conclusions: Our complete case series of A(H7N9) cases detected through
the routine ILI surveillance system provide contrasting clinical presentations to the generally much
more severe clinical picture of the majority of laboratory-confirmed A(H7N9) cases detected otherwise.
Our findings provide indirect evidence of a substantial proportion of mild disease and support the
existence of a “clinical iceberg” phenomenon in influenza A(H7N9) infections. For the clinician, our
findings reinforce vigilance to the diverse presentation that can be associated with influenza A(H7N9)
virus infections. Our results also suggest that large-scale community surveillance networks can be
useful as a population-based sampling tool to enhance understanding of the full spectrum of disease,
especially in the early phase of an evolving epidemic.published_or_final_versio
Detection of mild to moderate influenza A/H7N9 infection by China's national sentinel surveillance system for influenza-like illness: case series
published_or_final_versio
Illegal births and legal abortions – the case of China
BACKGROUND: China has a national policy regulating the number of children that a woman is allowed to have. The central concept at the individual level application is "illegal pregnancy". The purpose of this article is to describe and problematicize the concept of illegal pregnancy and its use in practice. METHODS: Original texts and previous published and unpublished reports and statistics were used. RESULTS: By 1979 the Chinese population policy was clearly a policy of controlling population growth. For a pregnancy to be legal, it has to be defined as such according to the family-level eligibility rules, and in some places it has to be within the local quota. Enforcement of the policy has been pursued via the State Family Planning (FP) Commission and the Communist Party (CP), both of which have a functioning vertical structure down to the lowest administrative units. There are various incentives and disincentives for families to follow the policy. An extensive system has been created to keep the contraceptive use and pregnancy status of all married women at reproductive age under constant surveillance. In the early 1990s FP and CP officials were made personally responsible for meeting population targets. Since 1979, abortion has been available on request, and the ratio of legal abortions to birth increased in the 1980s and declined in the 1990s. Similar to what happens in other Asian countries with low fertility rates and higher esteem for boys, both national- and local-level data show that an unnaturally greater number of boys than girls are registered as having been born. CONCLUSION: Defining a pregnancy as "illegal" and carrying out the surveillance of individual women are phenomena unique in China, but this does not apply to other features of the policy. The moral judgment concerning the policy depends on the basic question of whether reproduction should be considered as an individual or social decision
Interaction between CRHR1 and BDNF Genes Increases the Risk of Recurrent Major Depressive Disorder in Chinese Population
BACKGROUND: An important etiological hypothesis about depression is stress has neurotoxic effects that damage the hippocampal cells. Corticotropin-releasing hormone (CRH) regulates brain-derived neurotrophic factor (BDNF) expression through influencing cAMP and Ca2+ signaling pathways during the course. The aim of this study is to examine the single and combined effects of CRH receptor 1 (CRHR1) and BDNF genes in recurrent major depressive disorder (MDD). METHODOLOGY/PRINCIPAL FINDING: The sample consists of 181 patients with recurrent MDD and 186 healthy controls. Whether genetic variations interaction between CRHR1 and BDNF genes might be associated with increased susceptibility to recurrent MDD was studied by using a gene-based association analysis of single-nucleotide polymorphisms (SNPs). CRHR1 gene (rs1876828, rs242939 and rs242941) and BDNF gene (rs6265) were identified in the samples of patients diagnosed with recurrent MDD and matched controls. Allelic association between CRHR1 rs242939 and recurrent MDD was found in our sample (allelic: p = 0.018, genotypic: p = 0.022) with an Odds Ratio 0.454 (95% CI 0.266-0.775). A global test of these four haplotypes showed a significant difference between recurrent MDD group and control group (chi-2 = 13.117, df = 3, P = 0.016. Furthermore, BDNF and CRHR1 interactions were found in the significant 2-locus, gene-gene interaction models (p = 0.05) using a generalized multifactor dimensionality reduction (GMDR) method. CONCLUSION: Our results suggest that an interaction between CRHR1 and BDNF genes constitutes susceptibility to recurrent MDD
Construction of Vascular Tissues with Macro-Porous Nano-Fibrous Scaffolds and Smooth Muscle Cells Enriched from Differentiated Embryonic Stem Cells
Vascular smooth muscle cells (SMCs) have been broadly used for constructing tissue-engineered blood vessels. However, the availability of mature SMCs from donors or patients is very limited. Derivation of SMCs by differentiating embryonic stem cells (ESCs) has been reported, but not widely utilized in vascular tissue engineering due to low induction efficiency and, hence, low SMC purity. To address these problems, SMCs were enriched from retinoic acid induced mouse ESCs with LacZ genetic labeling under the control of SM22α promoter as the positive sorting marker in the present study. The sorted SMCs were characterized and then cultured on three-dimensional macro-porous nano-fibrous scaffolds in vitro or implanted subcutaneously into nude mice after being seeded on the scaffolds. Our data showed that the LacZ staining, which reflected the corresponding SMC marker SM22α expression level, was efficient as a positive selection marker to dramatically enrich SMCs and eliminate other cell types. After the sorted cells were seeded into the three-dimensional nano-fibrous scaffolds, continuous retinoic acid treatment further enhanced the SMC marker gene expression level while inhibited pluripotent maker gene expression level during the in vitro culture. Meanwhile, after being implanted subcutaneously into nude mice, the implanted cells maintained the positive LacZ staining within the constructs and no teratoma formation was observed. In conclusion, our results demonstrated the potential of SMCs derived from ESCs as a promising cell source for therapeutic vascular tissue engineering and disease model applications
Two-photon dual imaging platform for in vivo monitoring cellular oxidative stress in liver injury
Oxidative stress reflects an imbalance between reactive oxygen species (ROS) and antioxidants, which has been reported as an early unifying event in the development and progression of various diseases and as a direct and mechanistic indicator of treatment response. However, highly reactive and short-lived nature of ROS and antioxidant limited conventional detection agents, which are influenced by many interfering factors. Here, we present a two-photon sensing platform for in vivo dual imaging of oxidative stress at the single cell-level resolution. This sensing platform consists of three probes, which combine the turn-on fluorescent transition-metal complex with different specific responsive groups for glutathione (GSH), hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). By combining fluorescence intensity imaging and fluorescence lifetime imaging, these probes totally remove any possibility of crosstalk from in vivo environmental or instrumental factors, and enable accurate localization and measurement of the changes in ROS and GSH within the liver. This precedes changes in conventional biochemical and histological assessments in two distinct experimental murine models of liver injury. The ability to monitor real-time cellular oxidative stress with dual-modality imaging has significant implications for high-accurate, spatially configured and quantitative assessment of metabolic status and drug response
- …