Biomedical subjects
Publications and source records attributed to C Zhang.
This paper deals with the microscopic identification of the bulbs of 5 Fritillaria species from Yunnan Province, namely: F. cirrhosa, F. cirrhosa var. purpurea, F. cirrhosa var. viridiflava, F. delavayi and F. crassicaulis. Based on the shape, size, hilum and striation of the starch grain and the cuticular veins of the upper epidermis cell of the scales, these species could be distinguished obviously.
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1HNMR was employed to determine the liquid-crystalline transition temperature (TC) of the temperature-sensitive liposomes of futraful. It is a method with high sensitivity, high accuracy and furnishing more information. The 1HNMR spectra were made and studied. The rate of peak height increase of phospholipid correlates to the thermotropic phase transition of liposomes. The study shows that the TC of DPPC-liposomes and DSPC-liposomes is 36 degrees C and 48 degrees C, respectively. The TC of DPPC-DSPC-liposomes correlates with the proportion of the amount of DPPC and DSPC. The TC is not affected by futraful. The temperature-sensitive liposomes of futraful with TC of 41 degrees C were prepared which consisted of 60% DPPC and 40% DSPC.
In this paper we introduce a method and an implementation of blood flow imaging by means of backscattered Doppler ultrasound power. Compared with Color Flow Map technique based on autocorrelation, this technique is relatively angle independent, aliasing free and more sensitive to blood flow signal with noise background. We present the theory, experimental system and in-vitro experimental results. The realization of this technique means a new stage of color Doppler ultrasound imaging technique in our country is coming.
In this study the soft tissue cephalometric data of normal occlusion between 39 middle-old-aged people and 30 young people were compared. The results indicated: the upper lips of adults were getting thinner and longer, the soft tissues of lower lips and chins were getting thicker, so that the profiles changed obviously with the increasing of ages.
In this study the skeletal cephalometric data of normal occlusion between 39 middle-old-aged people and 30 young people were compared. The results indicated: the growth and reconstruction of the skeletal tissues of skull and jaws and face could still maintain for a period of time after grown-up. It mainly showed that skeletal tissues increased in vertical direction, the declination of occlusion plane became flat along with the increasing of ages.
A reliable CGC method was developed for the determination of docosahexenoic acid (DHA) in human serum. The serum sample was acidified by adding two drops of 4.5 mol.L-1 H2SO4, and DHA was extracted from serum using ethyl acetate. The extract was evaporated to dryness under nitrogen stream. To each residue, 1 ml 1.3 mol.L-1 methanolic hydrogen chloride solution was added and the mixture was allowed to stand for 30 min in 60 degrees C water bath. After derivatization, the mixture was extracted with 1 ml of n-hexane. The solvent was evaporated under a stream of nitrogen to dryness and the residue was dissolved in 30 microliters n-hexane and subjected to capillary GC, which was equipped with a fused silica capillary column (26.3 m x 0.25 mm ID) coated with FFAP (free fatty acid phase, 0.1 micron film thickness). Tricosanoic acid was used as an internal standard. The retention time of DHA-M and internal standard was 23.41 min and 20.79 min, respectively. The minimum detection concentration of DHA in serum was 40 ng.ml-1 with a serum volume of 200 microliters and S/N value of 2. A good linear relationship between the peak area ratios and concentrations was found at the DHA concentrations ranging from 25 to 200 micrograms.ml-1. The within-day and between-day precision was 5% and 9%, respectively.
Cholagogic capsule is mainly composed of Fiuctus Cardui, Mariae, Oleum Menthae Piperilae, Radix Currmae, olia taraxaci, Oleum Hyperici. It is shown that Cholagogic Capsule increase the rat's bile secretion significantly, but bile component is not influenced effectively, the retention jaundice models of which are created by ANIT isn't influenced effectively. It can reduce the mouse pinna swelling caused by dimethythenzene and depress the metatarsal swelling induced by carragenin, the antiinflammatory effect keeps for more than 4 h. It inhibits the contraction of gallbladder smooth musele of Guinea Pig caused by Ach. The results show that cholagogic Capsule increase bile secretion, antispasmodic and antiinflammatory effect. It is suggested the therapeutic effects of Cholagogic Capsule in sand-like calcul and acute chronic cholecystitis are related to the above pharmaological effects.
The experiments of some cultivated medthods of Polygonum multiforum show that the direct sowing of seeds is better than the cuttage, the index of reproduction and yield are higher, and the cultivated method can decrease expense. To cultivation period of 5 years, high yield and excellent qualty is available.
A new ELISA inhibition test for measuring serum Pre-S2Ab was developed to avoid the "double positive" phenomenon. One hundred and twenty samples with Pre-S2Ab negative were detected for Pre-S2Ab, the critical range for Pre-S2Ab in normal population was confirmed: a positive result was decided while the inhibition ration was over 50%, a negative result was decided while the inhibition ratio was less than 34%, and a dubious result was decided while the ratio was over 34% but less then 50%. At the same time, serum samples from sixty patients with chronic hepatitis B were detected for Pre-S2Ag and Pre-S2Ab, it showed that (1) the positive ratio of HBV DNA in patients with Pre-S2Ag positive was much higher than in patients with Pre-S2Ag negative (P < 0.01); (2) to the 46 patients with HBV DNA positive, Pre-S2Ag had a better relationship with HBV DNA than the HBeAg/Ab did (P < 0.01). Furthermore, to patients with acute hepatitis B, the presence of Pre-S2Ab was closely related to the prognosis of the disease, and the Pre-S2Ab assay could also be used to evaluate the preventive effect of HB vaccine containing Pre-S2Ag.
A fluorometric determination of trace Shachongdan (SCD) [(CH3)2NHCH (CH2S2O3- )CH2S2O3Na x H2O] is described. The method is based on the calcein display fluorescence in pH6-7 phosphate buffer solution, it react with Pd2+ to the fluorescence disappeared. The complex of SCD-Pd2+ is more stability than the complex of calcein-Pd2+, when SCD react with calcein -PdZ+, the calcein can be freed and its fluorescence appears once again. The fluorescence excitation and emission wavelenghts are 494 and 514nm. The linear range is 2 x 10(-7) mol/L-3 x 10(-6)mol/L and the detection limit is 6 x 10(-8)mol/L.
A 120-base phage phi29 encoded RNA (pRNA) has a novel role in DNA packaging. This pRNA possesses five single-base bulges, one three-base bulge, one bifurcation bulge, one bulge loop, and two stem loops. Circularly permuted pRNAs (cpRNA) were constructed to examine the function of these bulges and loops as well as their adjacent sequences. Each of the five single-base bulges was nonessential. The bifurcation bulge could be deleted and replaced with a new opening to provide flexibility for maintaining an overall correct folding in three-way junction. All of these nonessential bulges or their adjacent bases could be used as new termini for cpRNAs. The three-base (C18C19A20) bulge was dispensable for procapsid binding, but was indispensable for DNA packaging. The secondary structure around this CCA bulge and the phylogenetically conserved bases within or around it were investigated. Bases A14C15U16 were confirmed, by compensatory modification, to pair with U103G102A101. A99 was needed only to allow the proper folding of CCA bulge in the appropriate sequence order and distance constraints. Beyond these, the seemingly phylogenetic conservation of other bases has little role in pRNA activity. Each of the three stem loops was essential for procapsid binding, DNA packaging, and phage assembly. Disruption of the middle of any one of the loops resulted in dramatic reductions in procapsid binding, subsequent DNA packaging, and phage assembly activities. However, disruption of the loops at sequences that were close to double-stranded regions of the RNA did not interfere with pRNA activity significantly. Our results suggest that double-stranded helical regions near these loops were most likely not involved in interactions with components of the DNA-packaging machinery. Instead, these regions appear to be merely present to serve as a scaffolding to display the single-stranded loops that are important for pRNA tertiary structure or for interaction with the procapsid or other packaging components.
Calmodulin (CaM) is involved in cellular processes that are vital to cell proliferation and viability. Elevated CaM content is seen in transformed cells. Anti-CaM compounds alone are cytotoxic to tumor cells and are synergistic with certain cancer chemotherapeutic agents. However, all known CaM antagonists are nonselective, complicating interpretation of these studies. To more rigorously analyze the relationship between CaM protein expression and the behavior of cancer cells, tumor-derived cell lines were engineered such that CaM concentration could be manipulated by overexpressing CaM RNA. A full-length rat CaM I cDNA was inserted into the mammalian expression vector pMTCB6+ so that either CaM mRNA (sense) or antisense RNA was expressed under the control of an inducible metallothionein promoter. Constructs were introduced into C6 glioblastoma cells by liposome-mediated transfection and colonies were selected in G418. Significantly fewer clones were recovered from transfections with antisense vectors compared to CaM sense RNA or control (empty) vector alone. This difference was attributed to the cytotoxic effects of antisense CaM RNA as opposed to differences in transfection efficiencies. CaM expression was analyzed at the RNA level by Northern blotting and CaM protein concentrations were quantitated by immunofluorescence. Clones were identified in which CaM protein could be increased or decreased following exposure to zinc ions. Changes in CaM mRNA preceded changes in CaM protein by several hours. Overexpression of CaM had no significant effects on the growth of C6 cells. However, reductions in CaM lead to decreased growth rates of C6 cells and lowered cell viability.
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PURPOSE: Transgenic pigs with rhodopsin (Pro347Leu) mutation exhibited rod-cone degeneration. We compared the pathologic characteristics of the rod degeneration versus those of the cone cells. METHODS: The posterior and peripheral retinas of these transgenic pigs of age 4, 6, 8, 12, 24 and 33 weeks and normal pigs of age 4 and 8 weeks were studied by light and EM and morphometry. RESULTS: The pathologic changes observed in the posterior and peripheral retinas of the transgenic pigs could be conveniently described in 3 phases: I) an initial phase of rapid and extensive degeneration of the rod cells in the first 6 weeks of age; II) an acute phase of cone cell degeneration involving approximately half of the population and lingering rod degeneration in the 6 to 12 weeks of age; and III) a partial cone recovery to be followed by a chronic degenerative phase of the remaining cones cells from 12 to 33 weeks of age. CONCLUSION: Our study showed that the degenerative changes of rod cells could be differentiated from those of the cone cells. Cone and rod populations degenerated along different time schedule with different pathologic features. Hence, treatment for retinitis pigmentosa might vary with the different stages of the disease.
OBJECTIVE: To determine the antoantibodies and anti-interferon antibody in chronic viral hepatitis patients treated with interferon and the relation of the antibodies to the curative effect of interferon. METHODS: Forty chronic viral hepatitis patients (twenty cases for hepatitis B; twenty patients for hepatitis C) were studied. Indirect immunofluorescence assay (IFA) was used to measure the autoantibodies. Enzyme immunoassay (EIA) was used to measure the anti-interferon total antibody. RESULTS: Compared with normal groups, the autoantibodies in patients increased significantly (P < 0.01), and the anti-interferon antibody in chronic hepatitis B and hepatitis C patients had an obvious difference (P < 0.05). As for the curative effect, the presence or absence of autoantibodies did not have a distinct significance in patients treated with alpha-interferon, but the patients with anti-interferon antibody before or after therapy might have a different response to alpha-interferon. CONCLUSIONS: It was suggested that the presence of autoantibodies was not a contraindication to the use of interferon in patients with chronic viral hepatitis; the clinical significance of anti-interferon antibody should be further studied.
OBJECTIVE: To search and clone novel genes related to hypertension. METHODS: Using differential display, a RNA mapping method, we identified differentially expressed RNAs from cultured VSMCs of WKY and SHR. Down-expressed cDNAs of WKY were cloned. RESULTS: A novel cDNA (rHRG-1) obtained contained 4,160 bp nucleotides and an open reading frame which encoded 551 amino acid residues. Its molecular weight was 62,644. Northern blot analysis showed that the mRNA was expressed not only in VSMCs but in various rat tissues (heart, liver, brain, lung and kidney). Besides, the expression of rHRG-1 mRNA in various tissues (heart, liver, brain and kidney) of WKY rat was higher than that in those tissues of SHR. Semi-quantitative RT-PCR analysis showed that the expression of rHRG-1 mRNA was down-regulated by treating cells with angiotensin-II, endothelin-I or interleukin-I. VSMCs proliferation and hypertension-stimulating factor, but was up-regulated when treating cells with ANF, CGRP or adrenomedullin which could inhibit the proliferation of VSMCs and attenuate hypertension. These effects could be blocked or attenuated by corresponding antagonists or antibodies. CONCLUSION: The isolated novel rat cDNA (rHRG-1) is related to VSMCs proliferation or hypertension. It may antagonize the proliferation of VSMCs and may be involved in the formation of hypertension.
The two-dimensional image makes it difficult to determine the anatomic locations during the Functional Endoscopic Sinus Surgery (FESS), which causes many complications. The nasal columella is the best mark to identify the distance to the operating sites during the FESS. In this study, we measured the distances and angles from the base of columella to each important landmark: the anterior end of the middle turbinate, the ethmoid bulla, the posterior and superior end of the uncinate process, the basal lamina, the posterior wall of the ethmoid sinus, the posterior and superior wall of the sphenoid sinus, the anterior and posterior ethmoid artery and the ostia of the frontal sinus and the maxillary sinus in 12 Chinese adult cadavers (24 sides). Then a simple method was proposed to identify where you are operating on and where is the most perilous point. We also paid attention to the thickness of bony wall of the optic nerve canal, the superior wall of the sphenoid sinus, the papyraceous lamina and the septa of the ethmoid air cells and found that the former two were much thicker than the latters. The thicker bony wall may contribute enough safety to the optic nerve and the hypophysis in FESS.