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Biomedical subjects

C Li

Publications and source records attributed to C Li.

At least 613 records · Page 34Linked to original sources
PubMed1999

[Observation on efficacy of artemether compound against vivax malaria].

AIM: To observe the efficacy of artemether compound against vivax malaria. METHODS: Each artemether compound tablet contains 120 mg benflumetolum and 20 mg artemether. 132 patients with vivax malaria were divided into 3 groups. Group A, 36 patients received 8 tablets as an initial dose, followed by 4 tablets daily for 2 days; group B, 41 patients received 8 tablets as an initial dose, followed by 3 tablets daily for 4 days; group C, 55 patients receiving chloroguine-primaquine served as control. Two patients of group A were voluntarily to be bitten by Anopheles dirus before and after medication to observe the influence of artemether compound on the sporogony. RESULTS: The average defervescence times for groups A, B and C were 22.3 h, 23.2 h and 25.0 h (P > 0.05), respectively, the average parasite clearance times were 33.5 h, 30.5 h and 44.9 h, respectively, the average parasite clearance times of groups A and B were all significantly shorter than that of group C (P < 0.01). The replase rates of groups A, B and C were 84.9%, 78.8% and 22.9%, respectively, followed-up at nine months, the relapse rates of groups A and B were higher than that of group C(P < 0.01). CONCLUSION: Two regimens of artemether compound have the advantage of high efficacy against vivax malaria.

Adolescent↗
PubMed1999

[The applied anatomy and measure of nasolacrimal duct].

OBJECTIVE: To know the anatomy of nasolacrimal duct. METHOD: 80 half-skulls of chinese adult were used to observe shapes of the orifice. RESULT: Five shapes of the orifice were found. Slit-shape was the most in all shapes. 73 nasolacrimal ducts and situation of orifices have been measured with results as follows: (1) The nasolacrimal duct length is 14.14 mm (mean value); (2) The distance from the inferior margin of the anterior nostril to the anterior margin of the orifice (D.N.O.) is 29.00 mm (mean value); (3) The distance from the anterior attachment of the inferior turbinate to the anterior margin of the orifice is 11.70 mm (mean value); (4) The distance from the inferior margin of the anterior nostril to the anterior attachment of the inferior turbinate (D.N.T) is 18.30 mm (mean value). With analysis of linear regression, the relationship between the "D.N.T." and the nasolacrimal duct length, the "D.N.T." and the "D.N.O." is positive linear correlation respectively, "D.N.T." has been able to be measured easily, so the nasolacrimal duct length and the situation of the orifice have been recognized. CONCLUSION: D.N.T. may be used in clinical teaching and researching work.

Adult↗
PubMed1999

[Identification study on pig's hoofnail].

The identification characteristics of pig's hoofnail on properties and tissue slice was initially probed from the viewpoint of identification in this paper in order to make basis for the systematic research on replacing Squama manitis.

Animals↗
PubMed1999

Loss of anterior chamber-associated immune deviation during normal pregnancy in primates.

PURPOSE: We recently found that loss of anterior chamber-associated immune deviation was associated with normal pregnancy in rabbits. The purpose of this study is to further investigate whether the same events occurred in nonhuman primates. METHODS: Mid-pregnant cynomolgus monkeys were randomly selected. Bovine serum albumin (BSA) was inoculated in anterior chamber of eyes of nonpregnant and mid-pregnant monkeys that were subsequently immunized with BSA in adjuvant. Delayed-type hypersensitivity (DTH) was assessed by skin challenge. RESULTS: Non-pregnant monkeys of intracameral BSA proved able to acquire antigen-specific suppression of delayed-type hypersensitivity. By contrast, inoculation of BSA to anterior chamber of pregnant monkeys abolished the DTH-suppression effect. CONCLUSIONS: This is the first demonstration in primates that loss of anterior chamber-associated immune deviation occurred during normal pregnancy. The fluctuations of systemic hormone levels during normal pregnancy might influence local immunoregulation within the eye.

Animals↗
PubMed1999

[The role of spleen in induction and maintenance of anterior chamber-associated immune deviation in different species of animals].

PURPOSE: The importance of the spleen to the induction of anterior chamber-associated immune deviation (ACAID) in mice has been known for some time. Removal of the spleen within the first 4 days of injecting antigen into anterior chamber can abolish immune deviation and result in immunity. The purpose of this study is to explore the role of spleen in ACAID in other different species of animals. METHODS: After splenectomy and sham-splenectomy, bovine serum albumin (BSA) as a soluble antigen was inoculated into the anterior chamber (AC) of different animals (rat, rabbit and monkey) respectively. Recipient animals were immunized with BSA and complete Freund's adjuvant. Delayed-type hypersensitivity (DTH) was assessed by skin challenge. The maintenance time of deviant immune response was evaluated in the fixed interval. RESULTS: All the animals with receiving intraocular antigen inoculation, both in splenectomized group and in sham-splenectomized group, did not display DTH reaction. In addition, the maintenance time of immune deviation in both groups after AC inoculation of antigen was not significantly different. In contrast, all the animals without receiving intraocular antigen inoculation, both in splenectomized group and in sham-sple-nectomized group, displayed positive DTH reaction. CONCLUSIONS: The spleen may not play an important role in the induction and maintenance of ACAID in rat, rabbit and monkey. These data suggest that as the evolution progresses, the function of spleen may be replaced by other lymphatic organs.

Animals↗
PubMed1999

[The development of a hemorrhologity observating and measuring instrument].

A new instrument for observing blood cell state and the process of variation on hemorrheology has been developed. There are three ways of shear rate: setting by hand, automatically setting and simulating pulsative state. It can provide different variable flow fields. The shear rate can be set in the range from 0.1 to 1000 s-1. It needs only a little blood. It can be easyly and rapidely operated. it has clear images. The hemorrheology state of blood cells can be directly perceived through thd instrument by eyes. The display and measurement and record of blood cell's hemorrheology state can be finished in real time dynamically and simultaneously.

Equipment Design↗
PubMed1999

[Analysis of Cu-O bond stretching vibration in CuO2 plane of Bi-system high temperature superconductor].

Infrared absorption spectra of Bi-system high zero resistance temperature (Tc) superconductors were measured. The relation between Cu-O bond stretching vibration in CuO2 plane and superconducting properties of Bi-system high Tc superconductors were analysed and discussed. The result of analysis indicated that the change of absorption peak strength of Cu-O bond stretching vibration was similar to the change of Tc. The reason was related to the coupling between the phonon and free carrier. And according to the theory of molecule vibration, the frequencies of Cu-O bond stretching vibration in CuO2 plane were calculated on the base of simplified model.

English Abstract↗
PubMed1999

[The Raman spectra of rubidium titanyl arsenate].

The Raman spectra of rubidium titanyl arsenate (RTA) single crystal with different geometric arrangements were obtained and compared with those of rubidium titanyl phosphate (RTP), potassium titanyl arsenate (KTA) and potassium titanyl phosphate (KTP) single crystals. The assignments of various vibration modes were made according to the experimental results. The strong Raman scattering intensity implies that RTA crystal possesses large nonlinear optical property and the strongest scattering is from the TiO6 octahedron. From the mode splitting of AsO4 tetrahedron, we conclude that the distortion of AsO4 in RTA is larger than that of PO4 in KTP.

English Abstract↗
PubMed1999

[Determination of P in superhigh-P cast iron by EDXRF].

In this paper preparation of standard samples of superhigh-P cast iron has been studied and P in the samples has been determined by EDXRF and powder compacting. In the process the procedure of powder compacting and the software of a multifunctional Lucas-Tooth intenstity correction have been developed. The method is rapid and simple. Analytical results were satisfactory.

English Abstract↗
PubMed1998

A targeted disruption of the murine Brca1 gene causes gamma-irradiation hypersensitivity and genetic instability.

Germline mutations of the Brcal gene are responsible for most cases of familial breast and ovarian cancers, but somatic mutations are rarely detected in sporadic events. Moreover, mouse embryos deficient for Brca1 have been shown to die during early embryogenesis due to a proliferation defect. These findings seem incompatible with the tumor suppress function assigned to this gene and raise questions about the mechanism by which Brca1 mutations cause tumorigenesis. We now directly demonstrate that BRCA1 is responsible for the integrity of the genome. Murine embryos carrying a Brca1 null mutation are developmentally retarded and hypersensitive to gamma-irradiation, suggesting a failure in DNA damage repair. This notion is supported by spectral karyotyping (SKY) of metaphase chromosomes, which display numerical and structural aberrations. However, massive chromosomal abnormalities are only observed when a p53-/- background is introduced. Thus, a p53 dependent cell cycle checkpoint arrests the mutant embryos and prevents the accumulation of damaged DNA. Brca1-/- fibroblasts are not viable, nor are Brca1-/-:p53-/- fibroblasts. However, proliferative foci arise from Brca1-/-: p53-/- cells, probably due to additional mutations that are a consequence of the accumulating DNA damage. We believe that the increased incidence of such additional mutations accounts for the mechanism of tumorigenesis associated with Brca1 mutations in humans.

Animals↗
PubMed1998

A long terminal repeat of the human endogenous retrovirus ERV-9 is located in the 5' boundary area of the human beta-globin locus control region.

Transcription of the human beta-like globin genes in erythroid cells is regulated by the far-upstream locus control region (LCR). In an attempt to define the 5' border of the LCR, we have cloned and sequenced 5 kb of new upstream DNA. We found an LTR retrotransposon belonging to the ERV-9 family of human endogenous retroviruses in the apparent 5' boundary area of the LCR. This ERV-9 LTR contains an unusual U3 enhancer region composed of 14 tandem repeats with recurrent GATA, CACCC, and CCAAT motifs. This LTR is conserved in human and gorilla, indicating its evolutionary stability in the genomes of the higher primates. In both recombinant constructs and the endogenous human genome, the LTR enhancer and promoter activate the transcription of cis-linked DNA preferentially in erythroid cells. Our findings suggest the possibility that this LTR retrotransposon may serve a relevant host function in regulating the transcription of the beta-globin LCR.

Animals↗
PubMed1998

Olfactory dysfunction in multiple sclerosis. Relation to plaque load in inferior frontal and temporal lobes.

The question of whether and to what degree multiple sclerosis (MS) influences the ability to smell is controversial. We administered the University of Pennsylvania Smell Identification Test (UPSIT) to 26 MS patients and concurrently employed high-resolution magnetic resonance imaging (MRI) to quantify the number of demyelinating plaques within central brain structures. 38.5% of the patients demonstrated olfactory loss, with 7.7% exhibiting severe microsmia, 19.2% moderate microsmia, and 11.5% mild microsmia. None was anosmic, and no consistent left:right asymmetry in olfactory function or in hemispheric plaque numbers was observed. A strong negative correlation was found (Spearman r = -0.94) between UPSIT scores and the number of plaques within the inferior frontal and temporal lobes, but not within the rest of the brain. This study unequivocally demonstrates that a sizable proportion of MS patients suffer from olfactory loss commensurate with plaque activity within olfactory-related central brain regions, and is the first to explicate a physical basis for the olfactory dysfunction of any common neurologic disease.

Adult↗
PubMed1998

Role of transforming growth factor beta3 in lymphatic metastasis in breast cancer.

Transforming growth factor-betas (TGFbetas) play a prominent role in tumour growth and metastasis by enhancing angiogenesis and suppressing immune surveillance. Despite the increased interest in the effect of TGFbetas on tumour progression, little is known about the importance of TGFbeta3 and its receptor CD105 in breast cancer. In the present study, we measured the plasma levels of TGFbeta3, CD105-TGFbeta3 complexes and TGFbeta1 in 80 patients with untreated early-stage breast cancer using an enhanced chemiluminescence ELISA method. Of the 80 patients, 14 were histologically confirmed as having axillary lymph node metastases, while the remainder had no evidence of lymph node involvement. The results showed that levels of both TGFbeta3 and CD105-TGFbeta3 complex were significantly elevated in patients with positive lymph nodes compared to those without node metastasis. Furthermore, the levels of both TGFbeta3 and CD105-TGFbeta3 complex correlated with lymph node status. The only patient who died of the disease had very high plasma levels of TGFbeta3 and CD105-TGFbeta3 complex and positive lymph nodes; this patient developed lung metastases within 2 years of diagnosis. No significant correlation was seen between either TGFbeta3 or CD105-TGFbeta3 complex levels and tumour stage, size or histological grade. Plasma TGFbeta1 levels were not correlated with node metastasis, tumour stage, grade or size. Our data suggest that plasma levels of TGFbeta3 and CD105-TGFbeta3 complex may be of prognostic value in the early detection of metastasis of breast cancer.

Adult↗
PubMed1998

[Detection of Hep-2 and hepatoma cell line chromosomal aberration by using fluorescence in situ hybridization].

OBJECTIVE: To study the chromosomal aberration of hepatoma cell line (1172) and laryngocarcinoma cell line (Hep-2). METHODS: Fluorescence in situ hybridization (FISH) was used with nine chromosomal special libraries. RESULTS: The abnormal signals indicated that very complicated aberrations existed in the two cell lines. This suggested that the aberrations also existed in other chromosomes not yet studied. In 1172, the major type was structure aberration, but in Hep-2, numerical abnormality was shown in almost all chromosomes studied. CONCLUSION: Compared with traditional cytological methods, this technique has the advantages of being quicker and more accurate and sensitive.

Carcinoma↗
PubMed1998

Characterization of the promoter region of the rat neprilysin gene.

The neprilysin gene is composed of three distinct 5' noncoding exons which can be joined to the first coding exon to generate multiple mRNA species, all encoding the same protein. Genomic fragments containing upstream sequences of each of these three noncoding exons from the rat neprilysin gene were subcloned in the promoterless vector pXp1, which contains the luciferase reporter gene. Expression was compared between a neprilysin positive human spinal cord cell line, HSC-2, and neprilysin negative lines MCF-7, a human breast adenocarcinoma cell line and Hep G2, a human liver carcinoma cell line. The first and second promoter regions showed high activity in the positive cell line, but low activity in the negative cell lines. An analysis of the exon 1 promoter region showed that the proximal 85 nucleotides exhibited basal promoter activity. An enhancer-like sequence was found to be located within a 22-bp fragment located at -136 to -115. Scanning mutagenesis of a 29-bp fragment containing the enhancer-like sequence showed that changes in each 5- or 6-bp segment throughout this fragment decreased activity; however, mutations of the segment encompassing positions 19 to 24 eliminated >98% of the promoter activity. Binding of nuclear proteins from HSC-2 cells to this 29-bp fragment was observed by gel shift analysis. The ability of mutations within the 29-bp fragment to affect enhancer activity correlated with the ability of these mutant oligonucleotides to compete for the wild-type sequence in gel shift assays.

Animals↗
PubMed1998

A robust method for determining DNA binding constants using capillary zone electrophoresis.

Capillary zone electrophoresis (CZE or CE) with on-line UV detection was utilized to measure the binding constants between purified calf thymus DNA and a library of designed tetrapeptides which had been constructed using unnatural amino acids with thiazole ring side chains. Mixtures containing a constant amount of a tetrapeptide, the neutral marker (mesityl oxide), and varying concentrations of DNA were prepared and equilibrated at 8 degreesC for 12 h. CE was then utilized to separate unbound tetrapeptides from the DNA-peptide complex. The UV absorbance of the peak representing unbound tetrapeptide decreased incrementally as a result of increasing the concentration of DNA in the equilibrium mixture. The absorbance of the peak corresponding to the unbound tetrapeptide was obtained directly from the electropherogram and used in the calculation of the DNA-peptide binding constants. The binding constant for each tetrapeptide to calf thymus DNA was obtained from the negative slope of a Scatchard plot and a comparison of the binding constants for different peptides showed that the tetrapeptides in the library have DNA-binding affinities ranging from 10(2) to 10(6) M-1.

DNA↗