Examination of rofecoxib solution decomposition under alkaline and photolytic stress conditions

Rofecoxib is a highly active and selective cyclo-oxygenase II inhibitor. A stability-indicating method for the assay of rofecoxib has been developed using reverse-phase high-performance liquid chromatography (HPLC). Stress testing of rofecoxib was conducted during the method development and validation. HPLC analysis of rofecoxib solutions stressed under alkaline and photolytic conditions revealed the presence of several degradates. Two main degradates were determined to be the cyclization product formed by photo-cyclization and the dicarboxylate formed by ring opening in the presence of base and oxygen. The identities of these degradates were confirmed by comparison of UV spectra and HPLC retention time with the independently synthesized products. The mechanistic pathways for the formation of these degradates are discussed. Further improvement of the HPLC method's ruggedness has been made based on these studies.     

Species differences in the in vitro metabolic activation of the hepatotoxic pyrrolizidine alkaloid clivorine

Clivorine is a representative naturally occurring hepatotoxic otonecine-type pyrrolizidine alkaloid. Our previous study has demonstrated that clivorine induces liver damage via metabolic activation to form the reactive pyrrolic ester followed by covalent binding to liver tissue constituents. The present study investigated species differences in the in vitro metabolic activation of clivorine in the male rat and guinea pig of both sexes. In the male rat, the activation of clivorine to form the reactive pyrrolic ester was found as the only metabolic pathway. Moreover, the toxic tissue-bound pyrroles and four isolatable metabolites identified, namely DHR, 7-GSH-DHR, 7,9-diGSH-DHR, and clivoric acid, were all generated from further metabolism of this reactive intermediate. In the case of both sexes of guinea pig, the same activation was observed as the minor biotransformation, while an additional metabolic pathway, a direct hydrolysis of clivorine to form novel clivopic acid was identified as the predominant detoxification pathway. Furthermore, the formation rates for the toxic tissue-bound pyrroles and less toxic DHR were significantly slower and higher, respectively, compared with those in the male rat. In addition, the formation of the reactive pyrrolic ester was mediated by the CYP3A subfamily in both animals, while carboxylesterases might be responsible for the detoxification hydrolysis in guinea pig. The results suggest that the higher metabolic rates for detoxification hydrolyses and the lower formation rate for the toxic tissue-bound pyrroles play the key roles in guinea pig resistance to clivorine intoxication. Therefore, the male rat and guinea pig should be the suitable animal models for further studies of bioactivation and deactivation of otonecine-type PA, respectively.     

Reference range of hematocrit in the elderly with respect to altitude

The purpose of this paper is to provide a scientific basis for a unified standard of the reference value of old people's hematocrit in China. The reference values of healthy old people's hematocrit have been collected according to the Wintrobe methods; the relationship between the reference values of old people's hematocrit and altitude has been tested in this paper. It has been found that the reference value of old people's hematocrit increases when the altitude gradually increases, and such relationship is quite significant. The method of mathematical univariate regression analysis is used to deduce two regression equations: Y_1=44.1+0.00351x+/-4.5, Y_2=39.5+0.00298x+/-4.1. If the altitude value of a particular area of China is known, the reference value of old people's hematocrit there can be calculated by means of the regression equations. Furthermore, depending on the altitude, China can be divided into three districts: Qingzang District, Central District and Eastern District.     

Clinical and experimental study on separately decocted and mingly decocted jianweishu granule

Objective

To observe the difference in therapeutic effect of Chinese herbal granule decocted separately and mingly.

Methods

One hundred patients of functional dyspepsia of Spleen deficiency and Liver stagnancy type were treated with Jianweishu Granule (JWSG, ,a self-formulated recipe by the authors). Half of the patients received JWSG decocted separately, half of them received that decocted mingly. The therapeutic effects between the two groups were compared. Experimental observation on the effects of differently decocted remedies in rats was also conducted.

Results

The therapeutic effects obtained in the two groups were similar, with respective cure rate of 72 % and 70 % and the total effective rate 96 % in both group. There was insig1nificant difference between the two groups (P <0.05). Experimental study all showed no difference between the differently decocted remedies in inhibiting gastric acid, pepsin activity, gastric function regulation, small intestine movement improvement and pain alleviation in rats.

Conclusion

The therapeutic effects of JWSG decocted separately or mingly are the same. This fact provides a scientific basis for clinical use of granule form of single Chinese herbs.     

Secreted protein acidic and rich in cysteine promotes glioma invasion and delays tumor growth in vivo

Secreted protein acidic and rich in cysteine (SPARC) is highly expressed in human astrocytomas, grades II-IV. We demonstrated previously that SPARC promotes invasion in vitro using the U87MG-derived clone U87T2 and U87T2-derived SPARC-transfected clones, A2b2, A2bi, and C2a4, in the spheroid confrontation assay. Additional in vitro studies demonstrated that SPARC delays growth, increases attachment, and modulates migration of tumor cells in extracellular matrix-specific and concentration-dependent manners. Therefore, we propose that SPARC functionally contributes to brain tumor invasion and delays tumor growth in vivo, and that the effects of SPARC are related to the level of SPARC secreted into the extracellular matrix. To test these hypotheses, we stereotactically injected these clones into nude rat brains (six animals were injected per clone). Animals were sacrificed on day 7 to assess growth and invasion for all clones at the same time in tumor development. To determine whether SPARC delayed but did not inhibit growth, rats were injected with U87T2 or clone A2b2, and the animals were sacrificed on days 9 (U87T2) and 20 (A2b2), when the animals demonstrated neurological deficit. Brains were removed, fixed, photographed, paraffin embedded, and sectioned. Sections were then serially stained with H&E for morphological assessment of invasion and to measure tumor volume, immunohistochemically stained to visualize SPARC, subjected to in situ hybridization with the human AluII DNA-binding probe to identify human cells, and immunohistochemically stained with MIB-1 to measure proliferation index. The results demonstrate that SPARC promotes invasion in vivo at day 7. Both the low (A2bi) and the high (A2b2) SPARC-secreting clones produced invasive tumors, invading with fingerlike projections and satellite masses into adjacent brain, as well as along the corpus collosum. The intermediate SPARC secreting clone (C2a4) primarily migrated as a bulk tumor along the corpus collosum. SPARC significantly decreased tumor growth at day 7, as measured both by adjusted MIB-1 proliferation indices (U87T2 = 95.3 +/- 1.4 versus A2bi = 73.4 +/- 4.0, A2b2 = 30.8 +/- 6.7 and C2a4 = 15.7 +/- 13.0) and tumor volumes (U87T2 = 13.4 +/- 0.6 mm(3) versus A2bi = 4.5 +/- 0.6 mm(3), A2b2 = 1.1 +/- 0.1 mm(3), and C2a4 = 0.4 +/- 0.1 mm(3)). Furthermore, SPARC delayed but did not inhibit tumor growth. The patterns of invasion and the extent of growth delay correlated with the level of SPARC expression. We propose that the ability of SPARC to promote invasion depends on the level of its secretion and the resultant modulation of the level of adherence and motility induced. This demonstration that SPARC functionally contributes to brain tumor invasion in vivo suggests that SPARC is a candidate therapeutic target for the design of therapies directed toward inhibition of the invasive phenotype.     

Clone and expression of mutant M-CSF and its receptor from human leukemic cell line J6-1

Macrophage colony-stimulating factor (M-CSF) plays important roles in hematopoietic and immunologic systems. Some isoforms or mutations have been demonstrated including membrane-bound and cellular M-CSF, which associated with some leukemia, lymphoma and other solid tumors. We previously reported that the M-CSF-like membrane-associated factor (MAF-J6-1) and its receptor was found from human leukemic cell line J6-1. In this report, the cDNA of MAF-J6-1 and its receptor were cloned. The cDNA sequence of MAF-J6-1 shows a 768bp open reading frame (ORF) with 99.2% homology to m-M-CSF, but six site mutations, including two synonymous mutations and four missense mutations. The cDNA of MAF-J6-1-R has a 2916bp ORF shared 99.6% homology with M-CSF-R, but 13 site mutations, including six synonymous mutations and seven missense mutations. At the same time, a 1662bp mutant s-M-CSF cDNA, which has 10 site mutations including three synonymous mutations and seven missense mutations, was cloned from J6-1 cells. The cDNAs of MAF-J6-1 and MAF-J6-1-R were inserted into a mammalian expression plasmid pTARGET and were expressed in COS-7 cells that demonstrated by their specific MAb. COS-7 cells transfected with MAF-J6-1-R show obvious protein tyrosine kinase (PTK) activity. Our present work shows that MAF-J6-1 and its receptor are mutations of M-CSF and its receptor.     

Age-related total gray matter and white matter changes in normal adult brain. Part I: volumetric MR imaging analysis

BACKGROUND AND PURPOSE: A technique of segmenting total gray matter (GM) and total white matter (WM) in human brain is now available. We investigated the effects of age and sex on total fractional GM (%GM) and total fractional WM (%WM) volumes by using volumetric MR imaging in healthy adults. METHODS: Fifty-four healthy volunteers (22 men, 32 women) aged 20-86 years underwent dual-echo fast spin-echo MR imaging. Total GM, total WM, and intracranial space volumes were segmented by using MR image-based computerized semiautomated software. Volumes were normalized as a percentage of intracranial volume (%GM and %WM) to adjust for variations in head size. Age and sex effects were then assessed. RESULTS: Both %GM and %WM in the intracranial space were significantly less in older subjects (> or =50 years) than in younger subjects (<50 years) (P <.0001 and P =.02, respectively). Consistently, %GM decreased linearly with age, beginning in the youngest subjects. %WM decreased in a quadratic fashion, with a greater rate beginning only in adult midlife. Although larger GM volumes were observed in men before adjustments for cranium size, no significant differences in %GM or %WM were observed between the sexes. CONCLUSION: GM volume loss appears to be a constant, linear function of age throughout adult life, whereas WM volume loss seems to be delayed until middle adult life. Both appear to be independent of sex. Quantitative analysis of %GM and %WM volumes can improve our understanding of brain atrophy due to normal aging; this knowledge may be valuable in distinguishing atrophy of disease patterns from characteristics of the normal aging process.     

Reference values of erythrocyte sedimentation rate of adult healthy subjects

BACKGROUND: The purpose of this paper is to provide a scientific basic (rather than basic) for a unified standard of the erythrocyte sedimentation rate (ESR) reference value of healthy subjects in China between the ages of 41 and 75 years [corrected]. METHODS: ESR reference values of healthy subjects between 41 and 75 years of age were collected according to Wintrobe methods. The relationship between these healthy subjects' ESR reference values and altitude was tested in this paper. RESULTS: It was found that the ESR reference value of 41- to 75-year-old healthy subjects decreases when altitude gradually increases; the relationship is quite significant. Method of mathematical univariate regression analysis was used to deduce two regression equations: Y (1) = 14.89-0.00273 X +/- 3.52, and Y (2) = 23.92-0.00423 X +/- 5.34. CONCLUSION: If the altitude value of a particular area of China is known, ESR reference value of healthy subjects (41-75 years) ) can be calculated by regression equations. Furthermore, in terms of altitude, China can be divided into the following three districts: Qingzang District; Central District, and Eastern District.     

加强学生综合素质教育 培养合格的医学人才

实施素质教育,培养高素质的优秀人才是中国教育改革与发展的重大举措。将加强学生的素质教育摆在教学改革的首位;原有的教育模式已不能适应社会发展的需要,教育必须实行改革;人才素质必须更加优化,这些都为高等院校实施素质教育提出了新的任务和课题。因此,实施素质教育已成为时代的呼唤,科学技术和社会发展的需要。本文就如何提高大学生综合素质进行了一些探讨和实践。