[Clinicopathological and molecular genetic features of Crohn's disease]

Objective: To investigate the clinicopathological and molecular genetic characteristics of Crohn's disease (CD). Methods: A retrospective analysis was conducted on 52 CD patients who underwent surgical resection at the First Affiliated Hospital of Nanjing Medical University between January 2014 and June 2023. Clinical presentations and histopathological features were assessed. Whole-genome sequencing was performed on 17 of the samples, followed by sequencing and pathway enrichment analyses. Immunohistochemistry was used to assess the expression of frequently mutated genes. Results: Among the 52 patients, 34 were males and 18 were females, male-to-female ratio was 1.9∶1.0, with a median age of 45 years at surgery and 35 years at diagnosis. According to the Montreal classification, A3 (51.9%,27/52), B2 (61.5%, 32/52), and L3 (50.0%,26/52) subtypes were the most predominant. Abdominal pain and diarrhea were the common symptoms. Histopathological features seen in all 52 patients included transmural inflammation, disruption of cryptal architecture, lymphoplasmacytic infiltration, varying degrees of submucosal fibrosis and thickening, increased enteric nerve fibers and neuronal proliferation. Mucosal defects, fissure ulcers, abscesses, pseudopolyps, and adenomatous proliferation were also observed in 51 (98.1%), 38 (73.1%), 28 (53.8%), 45 (86.5%), and 28 (53.8%) cases, respectively. Thirty-one (59.6%) cases had non-caseating granulomas, and 3 (5.8%) cases had intestinal mucosal glandular epithelial dysplasia. Molecular analysis showed that 12/17 CD patients exhibited mutations in at least one mucin family gene (MUC2, MUC3A, MUC4, MUC6, MUC12, MUC17), and MUC4 was the most frequently mutated in 7/17 of cases. Immunohistochemical stains showed reduced MUC4 expression in epithelial cells, with increased MUC4 expression in the epithelial surface, particularly around areas of inflammatory cell aggregation; and minimal expression in the lower half of the epithelium. Conclusions: CD exhibits diverse clinical and pathological features, necessitating a comprehensive multidimensional analysis for diagnosis. Mutations and expression alterations in mucin family genes, particularly MUC4, may play crucial roles in the pathogenesis of CD.

Measuring Glutathione Regeneration Capacity in Stem Cells

Glutathione (GSH) is a chief cellular antioxidant, affecting stem cell functions. The cellular GSH level is dynamically altered by the redox buffering system and transcription factors, including NRF2. Additionally, GSH is differentially regulated in each organelle. We previously reported a protocol for monitoring the real-time GSH levels in live stem cells using the reversible GSH sensor FreSHtracer. However, GSH-based stem cell analysis needs be comprehensive and organelle-specific. Hence, in this study, we demonstrate a detailed protocol to measure the GSH regeneration capacity (GRC) in living stem cells by measuring the intensities of the FreSHtracer and the mitochondrial GSH sensor MitoFreSHtracer using a high-content screening confocal microscope. This protocol typically analyses the GRC in approximately 4 h following the seeding of the cells onto plates. This protocol is simple and quantitative. With some minor modifications, it can be employed flexibly to measure the GRC for the whole-cell area or just the mitochondria in all adherent mammalian stem cells.

Peroxiredoxin 5 protects HepG2 cells from ethyl β-carboline-3-carboxylate-induced cell death via ROS-dependent MAPK signalling pathways

Peroxiredoxin 5 (PRDX5) is the member of Prxs family, widely reported to be involved in various types of cell death. We previously found that PRDX5 knockdown increases the susceptibility of cell death upon oxidative stress treatment. Ethyl β-carboline-3-carboxylate (β-CCE), an alkaloid extracted from Picrasma quassioides, has been reported to play a role in neuronal disease, but its anti-cancer potential on liver cancers remains unknown. Here, we studied the effect of PRDX5 on ethyl β-carboline-3-carboxylate (β-CCE)-induced apoptosis of hepatomas. High expression level of PRDX5 was deeply related with the postoperative survival of patients with liver cancer, indicating that PRDX5 may be a biomarker of live cancer processing. Moreover, PRDX5 over-expression in HepG2 cells significantly inhibited β-CCE-induced cell apoptosis and cellular ROS levels as well as mitochondrial dysfunction. Signalling pathway analysis showed that β-CCE could significantly up-regulate the ROS-dependent MAPK signalling, which were in turn boosts the mitochondria-dependent cell apoptosis. Moreover, PRDX5 over-expression could reverse the anti-cancer effects induced by β-CCE in HepG2 cells. Our findings suggest that PRDX5 has a protective role on β-CCE-induced liver cancer cell death and provides new insights for using its anti-cancer properties for liver cancer treatment.

[Correlation of VISTA and PD-L1 expression with the clinicopathological features and prognosis in triple-negative breast cancer]

Objective: To investigate the expression of VISTA and PD-L1 in triple-negative breast cancer (TNBC) and to explore its relationship with clinicopathologic features and prognosis. Methods: Ninety TNBC patients who underwent surgical resections between 2016 to 2018 in Jiangsu Province Hospital were selected. The expression of VISTA and PD-L1 in both tumor cells and immune cells was evaluated by immunohistochemistry, and the relationship with clinicopathologic parameters and prognosis was analyzed. Results: VISTA was expressed in 17.8% (16/90) of the tumors. The expression of VISTA in tumor cells was related to a higher Ki-67 proliferation index (P=0.02) and higher number of tumor-infiltrating lymphocytes (TIL, P<0.01). VISTA was expressed in 71.1% (64/90) of the immune cells and the expression correlated with smaller tumor size (P=0.02), lower T stage (P=0.04), higher number of TIL (P<0.01), higher number of CD8⁺T cells (P=0.03) and higher Ki-67 proliferation index (P=0.02). PD-L1 was expressed in 17.8% (16/90) of the immune cells and the expression correlated with higher histologic grade (P=0.04), higher Ki-67 proliferation index (P=0.02) and higher number of TIL (P<0.01). VISTA expression was higher in immune cells within TNBC patients than PD-L1 (P<0.01). Among 90 TNBC patients, complete follow-up was obtained in 85 patients, 8 of whom had recurrences or metastasis after surgery, and two patients cases died of recurrences or metastasis. Conclusions: The expression rate of VISTA is higher than that of PD-L1 in TNBC. The expression of VISTA in immune cells predicts a lower T stage. VISTA may act as an effective immunotherapy target.

Pharmacological effects of Picrasma quassioides (D. Don) Benn for inflammation, cancer and neuroprotection (Review)

Picrasma quassioides (D. Don) Benn is an Asian shrub with a considerable history of traditional medicinal use. P. quassioides and its extracts exhibit good therapeutic properties against several diseases, including anti-inflammatory, antibacterial and anticancer effects. However, the composition of compounds contained in P. quassioides is complex; although various studies have examined mixtures or individual compounds extracted from it, studies on the application of P. quassioides extracts remain limited. In the present review, the structures and functions of the compounds identified from P. quassioides and their utility in anti-inflammatory, anticancer and neuroprotectant therapies was discussed. The present review provided up-to-date information on pharmacological activities and clinical applications for P. quassioides extracts.

Anticancer Effect of ERM210 on Liver Cancer Cells Through ROS/Mitochondria-dependent Apoptosis Signaling Pathways

BACKGROUND/AIM

Asian Traditional medicines are renowned for their antitumor properties and are efficacious in the clinical treatment of various cancer types. ERM210 is a Korean traditional medicine comprising nine types of medicinal plants. In the present study, we examined the pro-apoptotic effect and molecular mechanisms of the effects of ERM210 on HepG2 liver cancer cells.

MATERIALS AND METHODS

The cytotoxicity of ERM210 on HepG2 cells was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound-healing assays, and apoptosis and signaling pathways by fluorescence microscopy flow cytometry and western blotting.

RESULTS

ERM210 significantly impaired HepG2 cell viability and enhanced mitochondria-dependent cellular apoptosis in a time- and dose-dependent manner by up-regulating the expression of caspases 3, 7 and 9, and of BCL2 apoptosis regulator (BCL2)-associated X, apoptosis regulator (BAX) proteins, whilst down-regulating that of BCL2 protein. Furthermore, ERM210 treatment increased accumulation of cellular and mitochondrial reactive oxygen species (ROS) and significantly inhibited cell migration. Additionally, all these phenomena were reversed by treating with the ROS scavenger N-acetylcysteine. The analysis of signaling proteins revealed that ERM210 significantly up-regulated the phosphorylation of ROS-dependent mitogen-activated protein kinases (p38, extracellular-regulated kinase, and c-Jun N-terminal kinase in HepG2 liver cancer cells.

CONCLUSION

ERM210 exerts anticancer effects in HepG2 liver cancer cells by up-regulating ROS/mitochondria-dependent apoptosis signaling, providing new insight into the possibility of employing this traditional medicine for the clinical treatment of liver cancer.

[Relationship between clinicopathological features and prognosis of pancreatic ductal adenocarcinoma]

Objective: To investigate the relationship between clinicopathologic features and prognosis of pancreatic ductal adenocarcinoma located in the head of pancreas. Methods: A retrospective study was performed on 169 patients undergoing radical resection for pancreatic head cancer collected in the First Affiliated Hospital with Nanjing Medical University from January 2018 to April 2019. Univariate analysis and multivariate analysis were performed. Results: Patient's age, tumor differentiation, tumor maximum diameter, resection margin (several resection margins including portal vein groove resection margin, posterior resection margin, and uncinate resection margin), number of positive lymph nodes, number of regional lymph node dissected, and some preoperative and postoperative indicators were associated with prognosis (P<0.05). Direct tumor invasion of organs and surrounding tissues, perineural and vascular invasion, pathologic variants etc. had no statistical significance for survival time. Patient's age, maximum tumor diameter, degree of differentiation, uncinate incision margin, number of regional lymph nodes dissected, and preoperative CA19-9 were independent factors affecting prognosis. Patients older than 74 years of age, with tumors larger than 3 cm in diameter, poorly differentiated, less than 7 regional lymph node dissected, positive uncinate margin, and preoperative CA19-9 higher than 1.5×10⁵ U/L were independent risk factors in patients with pancreatic head cancer. Conclusions: Old age, tumor lager than 3 cm, poor differentiation, low examined lymph nodes, direct uncinate margin involvement and (or) with preoperative CA19-9 higher than 1.5×10⁵ U/L are related to poor prognosis of head pancreatic cancer.

Curcumin Activates ROS Signaling to Promote Pyroptosis in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND/AIM

Curcumin is a polyphenol that exerts a variety of pharmacological activities and plays an anti-cancer role in many cancer cells. It was recently reported that gasdermin E (GSDME) is involved in the progression of pyroptosis.

MATERIALS AND METHODS

HepG2 cells were treated with various concentrations of curcumin and cell viability was examined using MTT assay, apoptosis was analysed using flow cytometry, reactive oxygen species (ROS) levels using dihydroethidium, LDH release using an LDH cytotoxicity assay, and protein expression using western blot.

RESULTS

Curcumin increased the expression of the GSDME N-terminus and proteins involved in pyrolysis, promoted HspG2 cell pyrolysis and increased intracellular ROS levels. Moreover, inhibition of the production of intracellular ROS with n-acetylcysteine (NAC) improved the degree of apoptosis and pyrolysis induced by curcumin.

CONCLUSION

Curcumin induces HspG2 cell death by increasing apoptosis and pyroptosis, and ROS play a key role in this process. This study improves our understanding of the potential anti-cancer properties of curcumin in liver cancer.

Picrasma quassioides Extract Elevates the Cervical Cancer Cell Apoptosis Through ROS-Mitochondrial Axis Activated p38 MAPK Signaling Pathway

BACKGROUND/AIM

Picrasma quassioides (P. quassioides) is used in traditional Asian medicine widely for the treatment of anemopyretic cold, eczema, nausea, loss of appetite, diabetes mellitus, hypertension etc. In this study we aimed to understand the effect of P. quassioides ethanol extract on SiHa cervical cancer cell apoptosis.

MATERIALS AND METHODS

The P. quassioides extract-induced apoptosis was analyzed using the MTT assay, fluorescence microscopy, flow cytometry and western blotting.

RESULTS

P. quassioides extract induced cellular apoptosis by increasing the accumulation of cellular and mitochondrial reactive oxygen species (ROS) levels and inhibiting ATP synthesis. Pretreatment with N-Acetylcysteine (NAC), a classic antioxidant, decreased the intracellular ROS production and inhibited apoptosis. In addition, the P38 MAPK signaling pathway is a key in the apoptosis of SiHa cells induced by the P. quassioides extract.

CONCLUSION

The P. quassioides extract exerts its anti-cancer properties on SiHa cells through ROS-mitochondria axis and P38 MAPK signaling. Our data provide a new insight for P. quassioides as a therapeutic strategy for cervical cancer treatment.

Peroxiredoxin V Silencing Elevates Susceptibility to Doxorubicin-induced Cell Apoptosis via ROS-dependent Mitochondrial Dysfunction in AGS Gastric Cancer Cells

BACKGROUND/AIM

Peroxiredoxin V (Prx V) plays crucial roles in cellular apoptosis and proliferation in various cancer cells by regulating the cellular reactive oxygen species (ROS) levels.

MATERIALS AND METHODS

Here, we examined the possible regulatory effects of Prx V on doxorubicin (DOX)-induced cellular apoptosis and its mechanisms in the human gastric adenocarcinoma cell line (AGS cells).

RESULTS

Our findings suggest that Prx V knockdown may significantly increase the DOX-induced apoptosis by aggravating intracellular ROS accumulation. We also found that DOX-induced mitochondrial ROS levels and membrane permeability were significantly higher in short hairpin Prx V cells than in mock cells, and these phenomena were dramatically reversed by ROS scavenger treatment. Prx V knockdown also significantly upregulated the cleaved caspase 9, 3, and B-cell lymphoma 2 (Bcl2)-associated agonist of cell death/Bcl2 protein expression levels, suggesting that Prx V knockdown activates mitochondria-dependent apoptotic signaling pathways.

CONCLUSION

Taken together, this study suggests that Prx V may be a strong molecular target for gastric cancer (GC) chemotherapy, and further elucidates the role of Prx V in oxidative stress-induced cell apoptosis.

Regulatory function of peroxiredoxin I on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung cancer development

Smoking is a major cause of lung cancer, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the most important carcinogens in cigarette smoke. NNK modulates the expression of peroxiredoxin (Prdx) I in lung cancer. Prdx1 is upregulated in lung squamous cell carcinoma and lung adenocarcinoma, and considered a potential biomarker for lung cancer. The current article reviewed the role and regulatory mechanisms of Prdx1 in NNK-induced lung cancer cells. Prdx1 protects erythrocytes and DNA from NNK-induced oxidative damage, prevents malignant transformation of cells and promotes cytotoxicity of natural killer cells, hence suppressing tumor formation. In addition, Prdx1 has the ability to prevent NNK-induced lung tumor metabolic activity and generation of large amount of reactive oxygen species (ROS) and ROS-induced apoptosis, thus promoting tumor cell survival. In contrast to this, Prdx1, together with NNK, can promote the epithelial-mesenchymal transition and migration of lung tumor cells. The signaling pathways associated with NNK and Prdx1 in lung cancer cells have been discussed in present review; however, numerous potential pathways are yet to be studied. To develop novel methods for treating NNK-induced lung cancer, and improve the survival rate of patients with lung cancer, further research is needed to understand the complete mechanism associated with NNK.

[Clinicopathological features in relapsed diffuse large B-cell lymphoma]

Objective: To study the clinical pathological features of patients with relapsed diffuse large B-celllymphoma (DLBCL) and to provide evidence for early clinical screening of recurrent cases. Methods: The clinical and pathological data of the 20 patients, who had relapsed DLBCL (relapsed group) and were admitted to the First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2019, were included. Meanwhile, other 34 patients with DLBCL who had achieved complete response (CR) for 36 months or more (CR group) were used as controls.Statistical methods were used to retrospectively analyze the differences in general conditions, clinical characteristics, lab resultsand pathological features between the two groups. Results: Clinically, there were 6 males and 14 females with a median age of 55.5 (33-85) years in the relapsed group and 14 males and 20 females with a median age of 53 (15-89) years in the CR group. The relapsed and CR groups had significant difference in Ann Arbor stage (P=0.001), International Prognostic Index score (P=0.006), primary lesions (P=0.003), extranodal involvement (P=0.002), and hepatitis B viral infection (P=0.046), β2-MG level (P=0.029), LDH level (P=0.005) and CRP level (P=0.006), while the age (P=0.732), gender (P=0.416), ECOG score (P=0.248), B symptoms (P=0.511), the presence of hypoalbuminemia (P=0.279), anemia (P=0.983) and A/G(P=0.416) showed no statistical difference.Pathologically, compared with the CR group, the relapsed group was mostly non-GCB type (85% vs. 59%,P=0.048), with a higher CD5 positive rate (25% vs.3%,P=0.014) and a lower bcl-6　positive rate (60% vs. 88%,P=0.017), while the expression of Ki-67, CD10, bcl-2, MUM1, CD20 and PAX5 was not different between the two groups. Conclusion: Most of the patients with relapsed DLBCL are non-GCB type. The patients with CD5 positivity, stage III-IV, International Prognostic Index score 3-5, nodal origin, often involving>1 extranodal organ, abnormally elevated LDH, CRP and β2-MG level, and HBV infection are more likely to relapse.

Anti-tumor Properties of Picrasma quassioides Extracts in H-RasG12V Liver Cancer Are Mediated Through ROS-dependent Mitochondrial Dysfunction

BACKGROUND

Picrasma quassioides (PQ) is a traditional Asian herbal medicine with anti-tumor properties that can inhibit the viability of HepG2 liver cancer cells. H-Ras is often mutated in liver cancer, however, the effect of PQ treatment on H-Ras mutated liver cancer is unclear. This study aimed to investigate the role of PQ on ROS accumulation and mitochondrial dysfunction in H-ras mutated HepG2 (HepG2^G12V) cells.

MATERIALS AND METHODS

PQ ethanol extract-induced HepG2^G12V apoptosis was analyzed by the MTT assay, fluorescence microscopy, flow cytometry and western blotting.

RESULTS

PQ treatment affected cell migration and colony formation in HepG2^G12V cells. Cleaved-caspase-3, cleaved-caspase-9 and BCL2 associated agonist of cell death (BAD) expression levels were increased, while the levels of B-cell lymphoma-extra large (Bcl-xL) were decreased with PQ treatment. PQ treatment led to a reduction of H-Ras expression levels in liver cancer cells, thus reducing their abnormal proliferation. Furthermore, it led to increased expression levels of Peroxiredoxin VI, which regulates the redox signal in cells.

CONCLUSION

Taken together these results provide a new functional significance for the role of PQ in treating HepG2^G12V liver cancer.

Peroxiredoxin V Reduces β-Lapachone-induced Apoptosis of Colon Cancer Cells

BACKGROUND/AIM

Peroxiredoxin (Prx) V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS). Also, Prx V has been shown to mediate cell apoptosis in various cancers. However, the mechanism of Prx V-induced apoptosis in colon cancer cells remains unknown. Thus, in this study we analyzed the effects of Prx V in β-lapachone-induced apoptosis in SW480 human colon cancer cells.

MATERIALS AND METHODS

β-lapachone-induced apoptosis was analyzed by the MTT assay, western blotting, fluorescence microscopy, Annexin V staining and flow cytometry.

RESULTS

Overexpression of Prx V, significantly decreased β-lapachone-induced cellular apoptosis and Prx V silencing increased β-lapachone-induced cellular apoptosis via modulating ROS scavenging activity compared to mock SW480 cells. In addition, to further explore the mechanism of Prx V regulated β-lapachone-induced SW480 cells apoptosis, the Wnt/β-catenin signaling was studied. The Wnt/ β-catenin signaling pathway was found to be induced by β-lapachone.

CONCLUSION

Prx V regulates SW480 cell apoptosis via scavenging ROS cellular levels and mediating the Wnt/β-catenin signaling pathway, which was induced by β-lapachone.

On-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits

A consequent tendency toward high-performance quantum information processing is to develop the fully integrated photonic chip. Here, we report the on-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits. By introducing a periodically poled structure into the waveguide circuits, two individual photon-pair sources with a controllable electro-optic phase shift are produced within a Hong-Ou-Mandel interferometer, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9±0.9% visibility Hong-Ou-Mandel interference. The photon flux reaches ∼1.4×10(7)  pairs nm-1 mW-1. The whole chip is designed to contain nine similar units to produce identical photon pairs spanning the telecom C and L band by the flexible engineering of nonlinearity. Our work presents a scenario for on-chip engineering of different photon sources and paves the way to fully integrated quantum technologies.

Compact engineering of path-entangled sources from a monolithic quadratic nonlinear photonic crystal

An integrated realization of photonic entangled states becomes an inevitable tendency toward integrated quantum optics. Here we report the compact engineering of steerable photonic path-entangled states from a monolithic quadratic nonlinear photonic crystal. The crystal acts as a coherent beam splitter to distribute photons into designed spatial modes, producing the heralded single-photon and appealing beamlike two-photon path entanglement. We characterize the path entanglement by implementing quantum spatial beating experiments. Such a multifunctional entangled source can be further extended to the high-dimensional fashion and multiphoton level, which paves a desirable way to engineering miniaturized quantum light sources.

Heralded generation of multipartite entanglement for one photon by using a single two-dimensional nonlinear photonic crystal

We propose a compact scheme for the heralded generation of single-photon multipartite entanglement by using a single two-dimensional nonlinear photonic crystal. Studies have shown that by appropriate structure design, the single-photon entanglement shared among three spatially distinct optical modes can be generated through three concurrent spontaneous parametric down-conversion processes by using the other photon in an identical spatial mode as a trigger. Furthermore, we analyze the entanglement of such heralded single-photon tripartite W-type state theoretically. This method can be expanded for the heralded single-photon N-partite entanglement generation. This compact and stable quantum light source may act as a key ingredient in quantum information science.

Hong-Ou-Mandel interference mediated by the magnetic plasmon waves in a three-dimensional optical metamaterial

We studied the quantum properties of magnetic plasmon waves in a three-dimensional coupled metamaterial. A Hong-Ou-Mandel dip of two-photon interference with a visibility of 86 ± 6.0% was explicitly observed, when the sample was inserted into one of the two arms of the interferometer. This meant that the quantum interference property survived in such a magnetic plasmon wave-mediated transmission process, thus testifying the magnetic plasmon waves owned a quantum nature. A full quantum model was utilized to describe our experimental results. The results showed that the metamaterials could not only steer the classical light but also the non-classical light and they might have potential application in the future quantum information.

Single nucleotide polymorphisms and haplotypes of TLR6 gene in Chinese Cantonese population

Sequence polymorphisms in the coding region of Toll-like receptor 6 gene were investigated in Chinese Cantonese population. By amplifying and sequencing a 2787 bp segment containing the entire coding region of TLR6 gene of 191 individuals in Chinese Cantonese population, a total of seven single nucleotide polymorphisms (SNP) along with their frequencies were detected. Comparing these data with SNP published in dbSNP database of National Center for Biotechnology Information (NCBI), two SNP (+176T/C and +1408G/T) were firstly reported, and five SNP caused amino-acid substitution. Sixteen haplotypes and their distributions were reconstructed. Linkage disequilibrium analysis and neutrality test were also performed. Comparing with other ethnic populations, Chinese Cantonese displayed obvious differences in TLR6 polymorphism. It may in part reflect the ethnic diversity of pathogen susceptibility and facilitate to develop the disease-association studies as well as population genetics and evolutionary research.

Stimulated emission as a result of multiphoton interference

By performing an experiment on stimulated emission by two photons in the parametric amplification process and comparing it to a three-photon interference scheme, we present evidence in support of the idea that the underlying physics of stimulated emission is simply the constructive interference due to photon indistinguishability. So the observed signal enhancement upon the input of photons can be interpreted as a result of multiphoton interference of the input photons and the otherwise spontaneously emitted photon from the amplifier.

Four-photon interference with asymmetric beam splitters

Two experiments of four-photon interference are performed with two pairs of photons from parametric downconversion with the help of asymmetric beam splitters. The first experiment is a generalization of the Hong-Ou-Mandel interference effect to two pairs of photons while the second one utilizes this effect to demonstrate a four-photon de Broglie wavelength of lambda/4 by projection measurement.

Simultaneous determination of ergosterol, nucleosides and their bases from natural and cultured Cordyceps by pressurised liquid extraction and high-performance liquid chromatography

A simple method is described for the simultaneous determination of ergosterol, nucleosides and their bases in Cordyceps. The samples were extracted by using pressurised liquid extraction (PLE). The effects of experimental variables, such as solvent, temperature, static extraction time and cycles, on PLE efficiency have been studied. The results showed a strong influence of the solvent and temperature on extraction efficiency of PLE. The determination was achieved by high-performance liquid chromatography (HPLC) using a Zorbax NH2 analytical column (250 x 4.6 mm i.d., 5 microm) with diode-array detector (DAD). The automated preparation of the sample permits a very fast analysis which is an important goal for routine purpose.

Simultaneous determination of six main nucleosides and bases in natural and cultured Cordyceps by capillary electrophoresis

A simple method is described for simultaneous determination of six main nucleosides and bases including adenine, uracil, adenosine, guanosine, uridine and inosine in Cordyceps by capillary electrophoresis (CE). Chemometric optimization based on central composite design was employed to find the optimum resolution. The optimum factor space was defined by three parameters: buffer concentration, pH and concentration of acetonitrile as organic modifier. Resolution (Rs) was employed to evaluate the response function. A running buffer composed of 500 mM boric acid, adjusted pH to 8.6 with sodium hydroxide and 12.2% acetonitrile as modifier was found to be the most appropriate for the separation. The contents of the six components were determined by using adenosine monophosphate as an internal standard. Furthermore, hierarchical clustering analysis based on characteristics of 32 peaks in CE profiles from the tested 12 samples showed that natural and cultured Cordyceps were in different clusters. Adenosine and inosine were extracted as markers for discrimination of natural Cordyceps. The result of clustering based on the two peaks characteristics was in excellent agreement with that based on 32 peaks'. Thus, adenosine and inosine could be used as markers for quality control of natural and cultured Cordyceps.

Trichosanthin induced calcium-dependent generation of reactive oxygen species in human choriocarcinoma cells

The type-I ribosome-inactivating protein trichosanthin (TCS) has a broad spectrum of biological and pharmacological activities, including abortifacient, anti-tumor and anti-HIV. We found for the first time that TCS induced the generation of reactive oxygen species (ROS) in human choriocarcinoma cells (JAR cells) at the level of the single cell by using the fluorescent probe 2',7'-dichlorofluorescein diacetate with confocal laser scanning microscopy. TCS-induced ROS formation was shown to be dependent on the presence of extracellular Ca2+ and was further reduced when cytosolic Ca2+ was chelated by BAPTA-AM. The production of ROS increased rapidly after the application of TCS, which paralleled TCS-induced increase in intracellular calcium monitored using fluo 3-AM. Simultaneous observation of the nuclear morphological changes via two-photon laser scanning microscopy and production of ROS via confocal laser scanning microscopy revealed that ROS were involved in the apoptosis of JAR cells. The contribution of ROS was confirmed by experiments in which the antioxidant alpha-tocopherol prevented TCS-induced ROS formation and cell death. The finding that TCS induced calcium-dependent generation of ROS in JAR cells and that ROS were involved in the apoptosis of JAR cells might provide new insight into the anti-tumor and anti-HIV mechanism of TCS.

[Transmission electron microscopic observation on the liver and cerebral cortex in aging mice treated with sijunzi decoction]

By means of Transmission Electron Microscope (TEM), it was observed that Sijunzi Decoction (SD) affected the liver and ultrastructure of cerebral cortex in aging mice. The results showed that SD could improve the liver cells and the ultrastructure of cerebral cortex in aging mice, nourish the Viscera with Qi and blood by replenishing Spleen and Qi, adjust the Deficienoy of Viscera and promote the health of body and longevity.

[Comparative study on the anti-free-radical damage by vital energy-reinforcing method and blood-tonifying method]

A comparative study has been conducted on the anti-free-radical damage by the vital energy-reinforcing and blood-tonifying methods. The results shows that Sijunzi decoction and Siwu decoction can increase the vitality of SOD, accelerate the elimination of free-radical and inhibit the growth of LPO and MAO-B. This means that both these two methods help to delay senility and the vital energy-reinforcing one is more effective.

Chemical synthesis, molecular cloning, overexpression, and site-directed mutagenesis of the gene coding for pumpkin (Curcubita maxima) trypsin inhibitor CMTI-V

The gene encoding for a pumpkin (Curcubita maxima) trypsin inhibitor CMTI-V was synthesized chemically. The synthetic gene was prepared from four overlapping oligonucleotides by overlapping extension. The synthetic gene was amplified by polymerase chain reaction, cloned into a T7 expression vector and expressed in Escherichia coli as a fusion protein. The clone, namely 70-1, encoded a fusion protein containing 7 amino acid residues of the N-terminus of the bacterial protein rho 10 and the entire 68 residues of CMTI-V. The wild-type fusion protein constituted approximately 15% of the total bacterial protein mass and was purified to homogeneity in a single step by antibody affinity chromatography. The wild-type fusion protein possesses inhibitory activity toward trypsin and beta-Factor XIIa, but to a lesser extent when compared to the natural CMTI-V. A mutant, T43A, in which threonine at position 43 (P2 position) was replaced by alanine, was constructed. This mutant showed considerably lower specific inhibitory activity toward both trypsin and beta-Factor XIIa.

[Comparison of the effect of sijunzi decoction, siwu decoction and bazhen decoction on immune function in mice]

Sijunzi decoction, Siwu decoction and Bazhen decoction can antagonize the suppressive effect of hydrocortisone on proliferation of lymphocyte by spleen cells in C57BL/6J mice in vitro, and of the three decoctions Sijunzi works best. Sijunzi Decoction can antagonize the suppressive effect of cyclophosphamide on the delayed cutaneous hypersensitivity (DCH) induced by DNCB in mice and the production of hemolysin in mice immunized with SRBC. The three prescriptions all can enhance the clearance rate of iv charcoal particles as well as bone marrow cells inhibited by cyclophosphamide in mice, but Sijunzi decoction functions best of all.

Two-dimensional NMR studies of squash family inhibitors. Sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III

The solution structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III*) was investigated by two-dimensional proton nuclear magnetic resonance (2D NMR) spectroscopy. CMTI-III*, prepared by reacting CMTI-III with trypsin which cleaved the Arg5-Ile6 peptide bond, had the two fragments held together by a disulfide linkage. Sequence-specific 1H NMR resonance assignments were made for all the 29 amino acid residues of the protein. The secondary structure of CMTI-III*, as deduced from NOESY cross peaks and identification of slowly exchanging hydrogens, contains two turns (residues 8-12 and 24-27), a 3(10)-helix (residues 13-16), and a triple-stranded beta-sheet (residues 8-10, 29-27, and 21-25). This secondary structure is similar to that of CMTI-I [Holak, T. A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648], which has a Glu instead of a Lys at position 9. Sequential proton assignments were also made for the virgin inhibitor, CMTI-III, at pH 4.71, 30 degrees C. Comparison of backbone hydrogen chemical shifts of CMTI-III and CMTI-III* revealed significant changes for residues located far away from the reactive-site region as well as for those located near it, indicating tertiary structural changes that are transmitted through most of the 29 residues of the inhibitor protein. Many of these residues are functionally important in that they make contact with atoms of the enzyme in the trypsin-inhibitor complex, as revealed by X-ray crystallography [Bode, W., Greyling, H. J., Huber, R., Otlewski, J., & Wilusz, T. (1989) FEBS Lett. 242, 285-292].(ABSTRACT TRUNCATED AT 250 WORDS)

Proton NMR studies of Cucurbita maxima trypsin inhibitors: evidence for pH-dependent conformational change and His25-Tyr27 interaction

A pH-dependent His25-Tyr27 interaction was demonstrated in the case of Cucurbita maxima trypsin inhibitors (CMTI-I and CMTI-III) by means of nuclear magnetic resonance (NMR) spectroscopy. pH titration, line widths, peak shapes, deuterium exchange kinetics, and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) were employed to characterize a conformational change involving Tyr27, which was shown to be triggered by deprotonation of His25 around pH 6. A hydrogen bond is proposed to be formed between N epsilon of His25 and OH of Tyr27, as a distance between the atoms, His25 N epsilon and Tyr27 OH, of 3.02 A is consistent with a model built with NOE-derived distance constraints. Both the X-ray [Bode, W., Greyling, J.H., Huber, R., Otlewski, J., & Wilusz, T. (1989) FEBS Lett. 242, 282-292] and NMR [Holak, T.A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648] structures of CMTI-I at low pH (4.7-5.3) rule out such an interaction between the two aromatic rings, as the ring planes are oriented about 10 A away from each other. The presently characterized relative orientations of His25 and Tyr27 are of functional significance, as these residues make contact with the enzyme in the enzyme-inhibitor complex. Furthermore, trypsin assay and inhibitor-binding studies showed that conformations of trypsin and the squash inhibitor were functionally relevant only in the pH range 6-8. The pKa of His25 was determined and found to be influenced by Glu9/Lys substitution and by the hydrolysis of the reactive-site peptide bond between Arg5 and Ile6.(ABSTRACT TRUNCATED AT 250 WORDS)

A new protein inhibitor of trypsin and activated Hageman factor from pumpkin (Cucurbita maxima) seeds

A protein inhibitor (CMTI-V; Mr 7106) of trypsin and activated Hageman factor (Factor XIIa), a serine protease involved in blood coagulation, has been isolated for the first time from pumpkin (Cucurbita maxima) seeds by means of trypsin-affinity chromatography and reverse phase high performance liquid chromatography (HPLC). The dissociation constants of the inhibitor complexes with trypsin and Factor XIIa have been determined to be 1.6 x 10(-8) and 4.1 x 10(-8) M, respectively. The primary structure of CMTI-V is reported. The protein has 68 amino acid residues and one disulfide bridge and shows a high level of sequence homology to the Potato I inhibitor family. Furthermore, its amino terminus consists of an N-acetylates Ser. The reactive site has been established to be the peptide bond between Lys44-Asp45. The modified inhibitor which has the reactive site peptide bond hydrolyzed inhibits trypsin but not the Hageman factor.

Rubella vaccine in the People's Republic of China

The results of seroepidemiologic surveys indicate that rubella is widely prevalent in China. Congenital rubella infection has posed a threat. To control rubella and decrease the incidence of congenital rubella infection, an attenuated strain of rubella virus was developed in China. The original strain was isolated from a throat-swab specimen from a six-year-old girl with a clinical diagnosis of rubella. The strain was passaged and attenuated in human diploid cells and named BRD-2. The results of clinical trials showed that the BRD-2 virus strain has mild reactogenicity, satisfactory immunogenicity, and no transmissibility. The antigenicity and reactogenicity are comparable to those of strain RA27/3. It is anticipated that it may be put into production in the near future.