Biomedical subjects

Lin-Lin Zhang

Publications and source records attributed to Lin-Lin Zhang.

7 recordsLinked to original sources

PubMed2006

Spatial memory performance and hippocampal neuron number in osteoporotic SAMP6 mice.

The senescence-accelerated mouse strain P6 (SAMP6) is an inbred mouse that represents a clinically relevant model of senile osteoporosis. However, whether osteoporotic SAMP6 mice have cognitive deficits remains largely unexplored. Here, we used Morris water maze to assess reference memory and working memory performance in SAMP6 mice and SAMR1 controls, at 4 and 8 months of age. In addition, unbiased stereological techniques were used to estimate total neuron number in hippocampal CA1 subfield of the mice used in the behavioral study. Morris water maze test revealed impairments in working memory but not in reference memory of the 4- and 8-month-old SAMP6 mice compared with the SAMR1 mice at the same age. However, there were no significant differences in the total numbers of neurons in hippocampal CA1 subfield when comparing 4-month-old SAMR1 and 4-month-old SAMP6 and 8-month-old SAMR1 and 8-month-old SAMP6, which indicate that, in SAMP6 mice, the structural correlates of working memory deficits are to be found in parameters other than the number of neurons in hippocampal CA1 subfield. These findings suggest that SAMP6 mice exhibit selective cognitive deficits and highlight the importance of this mouse model for studying the brain alterations associated with osteoporosis.

Age Factors↗

PubMed2006

[Establishment of bone metastasis model of prostate cancer in nude mice by intratibia injection of human prostate cancer cell line Du145].

OBJECTIVE: To establish a bone metastasis model of prostate cancer by intratibia injection of Du145 in nude mice, observe the local growth of tumor in tibia and then assess application value of this model. METHODS: For 9 male nude mice, Du145 (5 x 10(6)) was injected in tibia by a TB syringe with a 29-gauge needle at a dose of 30 microl per mouse. Then the vital signs of the nude mice were observed. When the mice were dying, they were sacrificed, and the tissues of right hindlimbs, lymphatic nodes, lungs and livers were taken out, fixed in 10% formalin, embedded in paraffin, stained by HE and then observed microscopically. RESULTS: Incidence of bone tumor after intratibia injection was 67% (6 out of 9). About 48 days later, there were some small palpable nodes in right hind-limbs of the 6 mice and they couldn't walk normally. About 55 days later, cachexia occurred in them. After dissection, some carrion-like tissue grew from marrow cavity to muscular spatium, which was identified as tumor tissue by HE. The envelop of livers became crampy, and acute hepatitis could be diagnosed through microscopy, which represented a large scale of hepatocytic death, liver sinus dilatation and hyperemia, hepatic lobule infiltrated by lymphocyte, macrophage and inconspicuous hyperplasia. Since hypohepatia occurred too early, we couldn't detected distant metastases. CONCLUSION: The intratibia injection model is an optimal animal model to study metastasis of prostate cancer. It mimics the natural situation of human prostate cancer and will help to understand the mechanisms of androgen-independence and osseous metastasis, and tumor-host determinants of PSA expression.

Animals↗

PubMed2006

[Expression patterns of sonic hedgehog signaling molecules in human fetal prostate development].

OBJECTIVE: To investigate whether the sonic hedgehog signaling pathway is involved in the development of human fetal prostate, and to evaluate the changing staining patterns of its molecules, sonic hedgehog (SHH), patchedl (PTC1), smoothened (SMO), and GLI1, in the human fetal prostate at various gestation stages. METHODS: Fifteen human fetal prostate specimens at various developmental stages (10 - 39 weeks) were included in this study. SHH, PTC1, SMO and GLI1 were detected in all the specimens by immunohistochemical technique. All the slides were observed and assessed under the light microscope. RESULTS: SHH, PTC1, SMO and GLI1 could be detected in human fetal prostate tissues, and their expression formed two surges, the former at week 16, and the latter at week 28. The staining of SHH and SMO was distributed only in the ductal epithelium but not in the stroma. The expression of PTC1 and GLI1 could be found mainly in the epithelium, with minimal staining in the stroma. CONCLUSION: The sonic hedgehog signaling pathway is involved in the development of the human fetal prostate. The high expression of its molecules at early gestation stages might be associated with the induction of prostatic buds, while their abundant expression at later gestation stages might be related to the prostate ductal branching, growth, differentiation and morphogenesis.

Gene Expression Regulation, Developmental↗

PubMed2006

[Type IV collagenase expression in human prostate carcinoma cell lines with different metastasis potentials].

OBJECTIVE: To investigate the correlation between type IV collagenase expression and metastatic potential of human prostate carcinoma cells. METHODS: Human prostate carcinoma cell lines (LNCaP and C4-2B) with different metastatic potentials were selected. Using SABC immunocytochemical staining and zymographic analysis, we detected the difference of type IV collagenase expression and activity between the two cell lines. RESULTS: The expression of type IV collagenase (MMP-2, MMP-9) could be detected in both LNCaP and C4-2B, mainly in cytoplasm, much higher in C4-2B than in LNCaP (P < 0.01). The activities of type IV collagenase in the conditioned medium of prostatic carcinoma cell LNCaP was the lowest, and the quantitative estimation values of MMP-2 and MMP-9 were 0.89 +/- 0.02 and 0.86 +/- 0.01, respectively. However, the quantitative estimation values of MMP-2 and MMP-9 in the conditioned medium of C4-2B were 96.32 +/- 4.36 and 33.89 +/- 1.84, respectively. Compared with LNCaP, the activity of type IV collagenase in C4-2B was much higher (P < 0.01). CONCLUSION: Compared with LNCaP, the higher production capability of type IV collagenase in C4-2B may possibly contribute to its invasive and metastatic potentials. The expression of type IV collagenase of human prostate carcinoma cells is closely correlated to the metastatic and invasive potential.

Cell Line, Tumor↗

PubMed2005

[Study on rhG-CSF modified with polyethylene glycol].

Monomethoxy Polyethylene Glycol(mPEG20000) was activated by N-hydroxysuccinimede and analyzed by infrared spectrum and hydrolysis kinetics. In order to propose the optimized reaction conditions of mono-PEGylated rhG-CSF, orthogonal design of the experiment was investigated. Ion exchange chromatography was used to separate and purify PEGylated rhG-CSF from unPEGylated rhG-CSF. The purity of mono-PEGylated rhG-CSF was analyzed by high performance liquid chromatography (HPLC) to be 97%.

Granulocyte Colony-Stimulating Factor↗

PubMed2004

[Principle of determining the composition of complexes with the ratio of double peak values at double wavelengths by UV spectrophotometry].

In this paper, a new method for determining composition ratio of complexes was studied with ratio of double peak values at double wavelengths by UV spectrophotometry. The ratio of the maximum peak value to the minimum peak value and the composition ratio of complexes are the same. The calculation formula for the composition of complexes is deduced in accordance with beer's law and the theory of dissociation equilibrium of complexes: N = (deltaA2epsilonlambda1(MR) - deltaA1epsilonlambda2(MR)/(deltaA2epsilonlambda1(R) - deltaA1epsilonlambda2(R). The calculated value and that obtained by traditional method are agreeable. The method is reliable, simple, visual and quick.

Algorithms↗

PubMed2002

[Genetic polymorphisms of 9 STR loci in Dongxiang ethnic group of China].

Genetic distribution for nine STR loci was determined in a Chinese Dongxing ethnic group based on STR genescan marked by fluorescence. Seventy-two alleles and 182 genotypes were observed in 94 unrelated Chinese Dongxiang individuals,with the corresponding gene frequency and genotype frequency being 0.0053-0.5825 and 0.0106-0.2660 respectively. The genotypes of nine STR loci were in accordance with the Hardy-Weinberg equilibrium (P>0.05). The statistical analysis of nine STR loci showed PIC (polymorphism information content, PIC) = or > 0.6378, H(heterozygosity, H) = or > 0.6500, DP (discrimination power, DP) = or > 0.8216, PPE (probabilities of paternity exculation, PPE) = or > 0.4903. The result indicated that there was a significant difference between Dongxiang ethnic group and the white and the black. There was no significant difference in Han nationality. These result filled the Dongxiang ethnic group-a specific group of Chinese into the genetic database and played an important role in Chinese population genetic study and forensic medicine application.

English Abstract↗