[Determination of cinobufagin and resibufogenin in liver tissue by HPLC-MS/MS].

OBJECTIVE: To develop a sensitive and accurate assay for detecting cinobufagin and resibufogenin in liver tissue using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). METHODS: The homogenization of liver tissue with internal standard dexamethasone was extracted with dichloromethane. The extracts with methanol were purified through ProElut C18 solid phase extraction and tested in positive electrospray ionization with multiple reaction monitoring of HPLC-MS/MS. RESULTS: The good linear relationship of cinobufagin and resibufogenin in liver tissue were 1-204 ng/g and 1-206 ng/g, respectively. The minimal detection threshold (S/N > or = 3) of this method was 0.3 ng/g for both cinobufagin and resibufogenin. The matrix effect was 96.5%-126.7%. The extraction recovery coefficient was 70.0%-82.3%. The precision of intra-day and inter-day was less than 10%. CONCLUSION: This method is sensitive and reliable, and can be used in forensic toxicological analysis.

Ophthalmic findings in a family with early-onset isolated ectopia lentis and the p.Arg62Cys mutation of the fibrillin-1 gene (FBN1).

PURPOSE: The purpose of this paper is to describe ophthalmic findings in a family with isolated ectopia lentis (EL) caused by a specific FBN1 mutation. METHODS: Detailed family histories and clinical data were recorded for six isolated EL patients of 11 family members. The ophthalmological and systematic examinations were performed on patients and unaffected members of the investigated family. The detailed ocular examinations included visual acuity, anterior chamber depth, pupil size, lens location, optometry, central corneal thickness, keratometry, slitlamp examination, fundus examination, axial length, ocular B-ultrasound, gonioscope checking, ultrasound biomicroscopy (UBM) and intraocular pressure (IOP; Goldmann applanation tonometer). Systematic examinations included the measurement of echocardiogram, height, arm span, skull, face, jaw, tooth, breast bone, spinal column, and skin. Genomic DNA was extracted using the phenol-chloroform extraction method for all subjects, and sequencing was carried out on an ABI Prism 3730 Genetic Analyzer. RESULTS: A heterozygous mutation, c.184C>T (p.Arg62Cys) in exon 2 of FBN1 was identified in all affected members but was not found in any unaffected member of the family. Our study presented detailed clinical manifestations, including some novel ophthalmic findings, such as pupillary abnormality, different types of glaucoma, and progressive hyperopia. CONCLUSIONS: Ophthalmic findings and the p.Arg62Cys mutation of FBN1 gene were reported in a family with early-onset isolated ectopia lentis.

[LC-MS/MS analysis of determination of strychnine and brucine in formaldehyde fixed tissue].

OBJECTIVE: To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis. METHODS: The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid : 0.1% formic acid-acetonitrile (75:25). Electrospray ionization (ESI) source was utilized and operated in positive ion mode. Multiple reactions monitoring (MRM) mode was applied. External standard method was applied for quantitation. RESULTS: The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002-2.0 microg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection (LOD) of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%. CONCLUSION: Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.

[Subcellular mimical localization of the ATP synthase B subunit from Clonorchis sinensis under different conditions of cell cycling].

OBJECTIVE: To investigate the subcellular localization of ATP synthase b subunit from Clonorchis sinensis under different conditions of Hela cell cycling, and the effect of this protein on the expression of its encoding-gene and homologous host genes. METHODS: pEGFP-N1-CsATP-synt_B and the vector pEGFP-N1 were transfected into Hela cells, respectively. Transfected cells were synchronized in G0/G1 by serum starvation, G1/S, S cells by double thymidine block, and G2/M cells by thymidine-Nocodozale block. After synchronization, the subcellular localization of the expressed fusion protein was observed with a laser confocal microscope. The expression level of this fusion protein in cells was detected by flow cytometry (FCM). The expression of CsATP-synt_B and HomoATP-synt_B in different cell cycle phases accessed by RT-PCR. RESULTS: FCM results indicated that in the G0/G1 phase the expression of pEGFP-N1 vector was decreased significantly, while pEGFP-N1-CsATP-synt_B expression showed an upward trend. In the other phases of cell cycle, the protein expression was similar in the above two kinds of plasmids. The intact CsATP-synt_B was expressed in mitochondria in the G0/G1, S, and G2/M phases and nucleus during G1/S phase. After the fusion proteins entered the nucleus, the mRNA expression of CsATP-synt_B and HomoATP-synt_B increased significantly. CONCLUSION: CsATP-synt_B can be expressed in the nucleus during G1/S phase, and regulated by the cell cycle and energy requirements.

[Tissular and subcellular localization of the ATP synthase B subunit in Clonorchis sinensis].

OBJECTIVE: To illustrate the distribution of ATP synthase b subunit in the tissue of Clonorchis sinensis adult and its subcellular mimical localization in HeLa cells. METHODS: With the antiserum against recombinant CsATP-synt_B protein raised from SD rats as primary antibody, paraffin sections of the adult of C. sinensis were processed by the method of fluorescent immunohistochemistry to observe the distribution of CsATP-synt_B protein in adult worm. According to the prediction by bioinformatics of the definite mitochondrial targeting sequence (MTS) and probable Bipartite nuclear localization signals (NLS_BP)in CsATP-syntB sequence, recombinant pEGFP-N1 plasmids containing the intact and three defective CsATP-synt_B sequence with single defect of MTS or NLS_BP or double defect respectively were constructed. The recombinant plasmids and the control plasmid-pEGFP-N1, pEYFP-Mito and H2B-CFP, were transfected into the HeLa cells by Lipofectamine 2000 reagent and the subcellular location of the GFP fusion protein was observed with confocal microscopy. RESULTS: The CsATP-synt_B protein appeared to distribute all over the adult worm, especially abundant on the acetabulum, ovary, vitellarium and tegument. The intact CsATP-synt_B was definitely expressed in mitochondria and/or nucleus of infected HeLa cells, whereas the MTS-deleted mutant only in cytoplasma and nucleus, the NLS_BP-deleted mutant in mitochondria and cytoplasm, and the double defect mutant only in cytoplasm. CONCLUSION: The distribution of CsATP-synt_B in adult is accord with that of mitochondria, and mainly exits in the organs and the tissues of active energy metabolism. This study first predicted and confirmed that CsATP-synt_B can be expressed in the nucleus.