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Biomedical subjects

H Guo

Publications and source records attributed to H Guo.

At least 145 records · Page 8Linked to original sources
PubMed1999

The change of insulin-like growth factor-1 in diabetic patients with neuropathy.

OBJECTIVE: To evaluate the possible relationship between insulin-like growth factor-1 (IGF-1) and diabetic neuropathy (DNP). METHODS: Sixty-nine patients with Type 2 non-insulin-dependent diabetes (54 with peripheral neuropathy and 15 without neuropathy) were observed. Normal controls were 34 non-diabetic persons. Diabetic peripheral neuropathy diagnosis was carried out taking into account results of NS, ND, NC and AF. After an overnight fast, blood was taken for IGF-1, glucose, hemoglobin Alc, C-peptide, and insulin. Plasma IGF-1 was measured by radioimmunoassay (RIA) method. RESULTS: The neuropathic group had significantly lower levels for IGF-1 (86.43 ng/ml +/- 45.18 ng/ml) compared to normal controls (119.68 ng/ml +/- 89.42 ng/ml) (P < 0.05), and to diabetic patients without neuropathy (113.75 ng/ml +/- 66.58 ng/ml) (P < 0.05). No significant difference was found between diabetic non-neuropathic group and normal control subjects (P < 0.05). In diabetic subjects there was a positive correlation (gamma = 0.27, P < 0.05) between IGF-1 and beat to variation in heart rate. There were negative correlation between IGF-1 and postprandial blood glucose (gamma = -0.3, P < 0.05), and aspartic acid translocase (gamma = -0.27, P < 0.05). CONCLUSION: In diabetic patients with peripheral neuropathy there are abnormalities of IGF-1 that may contribute to the pathogeneses of diabetic neuropathy.

Aged↗
PubMed1999

[Surgical treatment of trigeminal neurinomas].

OBJECTIVE: To investigate the best surgical approach to remove of trigeminal neurinomas (TNs). METHODS: 75 patients with TNs in Huashan Hospital were reviewed retrospectively. RESULTS: In early group (1978 - 1984) conventional intradural approaches were used, and in late group (1985 - 1995) an epidural approach via the skull-base craniotomy was utilized. Total removal of was achieved in 58% (20/35) in the early group and 80% (32/40) (P < 0.05) in the late group. Temporary or permanent cranial nerves morbidities were 62.7%, 37% in the early group and 28.1%, 10% (P < 0.01) in the late group, respectively. CONCLUSIONS: The best surgical approach with microsurgical technique for removal of TNs is epidural approach or epiduro-transduro-transtentorial approach via a skull-base craniotomy except the tumor only confined to the posterior fossa.

Adolescent↗
PubMed1999

[Lutembacher's syndrome].

OBJECTIVE: To compare classical and acquired Lutembacher's syndrome (mitral restenosis after percutaneous balloon mitral valvuloplasty) in attempt to know their different in pathophysiology, diagnosis, and surgical treatment. METHODS: The data from 22 cases of classical and acquired Lutembacher's syndrome who underwent surgical treatment in the same period were analyzed. RESULTS: No death occurred in the classical group. In the acquired group the mortality however was 42.8% for those highly complicated with pulmonary hypertension and right heart failure. CONCLUSIONS: Classical Lutembacher's syndrome can be corrected satisfactorily. The acquired one deteriorates rapidly with severe pulmonary hypertension and right heart failure, and needs early surgical intervention reduce the operation mortality.

Adult↗
PubMed1999

[A follow-up study of anterior deciduous cross-bite].

OBJECTIVE: To determine the relationship between anterior deciduous crossbite and anterior permanent crossbite, Angle classification of malocclusion and class III jaw relationship through a follow-up study in community children. METHODS: A follow-up study was done six years later in 102 children who were out of 120 children having anterior deciduous crossbite detected in a survey of six years before. Other 102 children with normal occlusion of deciduous and permanent teeth were treated as the control group. RESULTS: There were 51 out of 102 cases developed anterior permanent crossbite. In comparison with the group with 1-2 anterior deciduous crossbite, the group with more than two neighboring anterior deciduous crossbite had more significant probability to turn into anterior permanent crossbite, OR = 6.8 (95% CI: 2.7-17.6). The patients with more than 2 neighboring anterior deciduous teeth crossbite had significantly more chance of developing Angle III malocclusion and class III jaw relationship than those in the control group and those with 1-2 anterior deciduous teeth crossbite. CONCLUSION: Clinical orthodontists should pay more attention to the patients with more than 2 neighboring anterior deciduous crossbite.

Adolescent↗
PubMed1999

[Influence of EBV latent membrane protein 1 gene on the proliferation of epithelial cells].

In order to study the influence of EBV latent membrane protein (LMP1) gene on the proliferation of epithelial cells and the role of LMP1 creating to epithelial cell carcinomas, EBV LMP1 gene eukaryotic expression plasmid was transfected into human embryo kidney epithelial cells. The expression of LMP1 protein in transfected cells was detected. Observing the formation of colonies in soft agar, the value of MTT absorbed and the expression of PCNA, the results showed that the transfected cells grew vigorously and formed more colonies in soft agar, the MTT uptake and PCNA expression were apparently increased. The conclusion was that LMP1 gene could alter the biological behaviours of epithelial cells, promote cell growth, proliferation and transformation and endowed the transfected cells with growth characteristics like tumor cells.

Cell Division↗
PubMed1999

[Immune responses in mice vaccinated with recombinant plasmid pcDNA3 containing ROP1 gene from Toxoplasma gondii].

AIM: To observe the immune responses in BALB/c mice vaccinated with the constructed recombinant plasmid, pcDNA3, containing ROP1 gene from Toxoplasma gondii. METHODS: The plasmid DNA obtained by alkaline lysis were injected into the left leg of each mouse at a dosage of 100 micrograms. A booster vaccine was given using the same dosage two weeks later. Control groups were injected with the pcDNA3 blank plasmid and normal saline, respectively. 30, 50 and 70 days after the booster injection, the proliferation activity of T lymphocytes and the NK cell activity were determined using MTT assay, the number of CD4+/CD8+ T cells with indirect immunofluorescence assay and the titer of IgG antibody by ELISA. RESULTS: The spleens of mice enlarged obviously after immunization with pcDNA3-ROP1. The activity of proliferation of spleen T lymphocytes was higher in the immunization group than in the control groups; The NK cell activity in the immunization group was higher than those of control ones. The number of CD4+ T cells showed no obvious increase but CD8+ T cells obviously increased. The titer of IgG antibody in the immunization group showed no significant increase until 90 days later. CONCLUSION: Vaccination of mice with the recombinant plasmid, pcDNA3-ROP1, could elicit cellular and humoral immune response in mice.

Animals↗
PubMed1999

[Cellular immune response in mice vaccinated with uv-attenuated Toxoplasma gondii ZS1 strain trophozoites].

AIM: To explore the protective effect and cellular immune response of uv-attenuated ZS1 strain trophozoites of Toxoplasma gondii in mice. METHODS: The ZS1 strain trophozoites of T. gondii were irradiated by uv-light with 2537 A wave length for 60 minutes. Mice were divided into 4 groups. Group 1 was vaccinated alone, group 2 was challenged with normal ZS1 trophozoites on d45 after vaccination, group 3 was infected alone, and group 4 was normal control. The changes in splenic T cell proliferation, level of CD4+ and CD8+ T cell, and NK cell activity were compared. RESULTS: Group 1 mice survived normally, no trophozoite, pseudo-cyst or cyst was detected in the tissues on d49 after vaccination. Group 2 mice survived longer than those of group 3. The T lymphocyte proliferation in response to soluble antigen of T. gondii was significantly enhanced in group 2, and suppressed in group 3. The level of CD4+ T cell in group 2 was decreased, resulting in a reverse of CD4+/CD8+ ratio. The NK cell activities in groups 1, 2 and 3 were all significantly increased. CONCLUSION: The uv-attenuated vaccine of T. gondii ZS1 strain could induce certain protective immunity against challenge infection, in which CD8+ T cell and NK cell might play an important role.

Animals↗
PubMed1999

[The objective evaluation of hearing aids].

OBJECTIVE: To objectively evaluate the effect of hearing aids. METHOD: The procedure involved eliciting ABRs by clicks and slow vertex response (SVRs) by tone pips to the aided and unaided ear presented in sound field. RESULT AND CONCLUSION: There has high relativity between the thresholds of SVRs and free field pure tone audiometry. There has no significant difference between the gains from SVRs and free field pure tone audiometry.

Adolescent↗
PubMed1998

Tumor-derived EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates collagenase transcription through MAPK p38.

EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates fibroblast metalloproteinases (MMP) 1, 2 and 3 (Kataoka et al. (1993) Cancer Res. 53, 3154-3158). Here we focus on MMP-1, showing that in lung tumors, MMP-1's cognate mRNA is strongly expressed in stromal fibroblasts adjacent to EMMPRIN-expressing tumor cells. In vitro, EMMPRIN upregulates MMP-1 mRNA expression in a concentration-dependent manner, with a peak accumulation at 24 h. The response is genistein-sensitive, suggesting it is dependent on tyrosine kinase activity. Analysis of tyrosine phosphorylation-dependent MAP kinases ERK 1/2, SAPK/JNK, and p38 showed that the activity of p38 but not that of the other 2 kinases was elevated in response to EMMPRIN. That p38 activity was required for EMMPRIN stimulation of MMP-1 was evident from results showing that the p38 inhibitor SB203580 blocked this response. This is the first available information regarding the mechanism by which tumor-associated molecules upregulate MMP synthesis in stromal fibroblasts.

Antigens, CD↗
PubMed1998

Brefeldin A-mediated apoptosis requires the activation of caspases and is inhibited by Bcl-2.

Brefeldin A (BFA) has recently been shown to induce apoptosis in human tumor cells in a p53-independent fashion. In this study, BFA-induced apoptosis was analyzed in the human Jurkat T-cell line. Apoptosis occurred 8 h after treatment with BFA and at concentrations as low as 10 ng/ml and increased with the duration of BFA exposure. Forskolin, an inhibitor of BFA-induced deaggregation of the Golgi-microtubular complex in some cell lines, failed to reverse BFA-mediated apoptosis. Further study of the mechanism of BFA-induced apoptosis was conducted by using a series of peptide protease inhibitors. Complete inhibition of cell death was achieved with benzyloxycarbonyl-Val-Ala-Asp-fluromethylketone, a peptide inhibitor of the caspase protease family, and Z-Asp-Glu-Val-Asp-FMK, a specific inhibitor of caspase-3. Both Acetyl-Tyr-Val-Ala-Asp-chloromethylketone and Acetyl-Tyr-Val-Ala-Asp-aldehyde, selective caspase-1 (interleukin-1beta converting enzyme) inhibitors, exerted only partial protection of cells from apoptosis at higher concentrations. Z-Phe-Ala-FMK, a cysteine protease inhibitor lacking aspartate at the P1 position, did not have any impact on BFA-induced apoptosis. Furthermore, Jurkat cells transfected with the proto-oncoprotein Bcl-2, which is able to block various apoptotic conditions, showed remarkable resistance to the apoptotic effect of BFA. Thus, the data indicate that BFA-induced apoptosis requires caspase(s) activation, primarily the activation of caspase-3, and is inhibited by overexpression of Bcl-2.

Amino Acid Chloromethyl Ketones↗
PubMed1998

Characterization of the gene for human EMMPRIN, a tumor cell surface inducer of matrix metalloproteinases.

EMMPRIN (extracellular matrix metalloproteinase inducer) also known as CD147 and basigin, is a member of the immunoglobulin family that is present on the surface of tumor cells and stimulates nearby fibroblasts to synthesize matrix metalloproteinases. Using our EMMPRIN cDNA, we have isolated a cosmid clone that contains the human EMMPRIN gene. S1 analysis with a fragment of the gene clone and primer extension of the mRNA was performed to determine the transcription start site. PCR and sequence analysis have defined the exon/intron organization of the gene and show that it is highly conserved with the mouse EMMPRIN/basigin gene. About 950 bases of the 5'-flanking region were examined for transcription factor consensus binding sites, locating three SP1 sites and two AP2 sites. The transcription start site was found to be located in a CpG island. Elements in the proximal promoter region were conserved in the human and mouse genes.

5' Untranslated Regions↗
PubMed1998

Enhancement of blue-light sensitivity of Arabidopsis seedlings by a blue light receptor cryptochrome 2.

Cryptochrome is a group of flavin-type blue light receptors that regulate plant growth and development. The function of Arabidopsis cryptochrome 2 in the early photomorphogenesis of seedlings was studied by using transgenic plants overexpressing CRY2 protein, and cry2 mutant plants accumulating no CRY2 protein. It is found that cryptochrome 2 mediates blue light-dependent inhibition of hypocotyl elongation and stimulation of cotyledon opening under low intensities of blue light. In contrast to CRY1, the expression of CRY2 is rapidly down-regulated by blue light in a light-intensity dependent manner, which provides a molecular mechanism to explain at least in part that cryptochrome 2 functions primarily under low light during the early development of seedlings.

Amino Acid Sequence↗
PubMed1998

Regulation of flowering time by Arabidopsis photoreceptors.

The shift in plants from vegetative growth to floral development is regulated by red-far-red light receptors (phytochromes) and blue-ultraviolet A light receptors (cryptochromes). A mutation in the Arabidopsis thaliana CRY2 gene encoding a blue-light receptor apoprotein (CRY2) is allelic to the late-flowering mutant, fha. Flowering in cry2/fha mutant plants is only incompletely responsive to photoperiod. Cryptochrome 2 (cry2) is a positive regulator of the flowering-time gene CO, the expression of which is regulated by photoperiod. Analysis of flowering in cry2 and phyB mutants in response to different wavelengths of light indicated that flowering is regulated by the antagonistic actions of phyB and cry2.

Arabidopsis↗
PubMed1998

An intravitreal sustained-release triamcinolone and 5-fluorouracil codrug in the treatment of experimental proliferative vitreoretinopathy.

OBJECTIVE: To determine the efficacy and pharmacokinetics of an intravitreal sustained-release triamcinolone acetonide and 5-fluorouracil (TA/5-FU) codrug in the treatment of experimental proliferative vitreoretinopathy (PVR). METHODS: The therapeutic efficacy of the TA/5-FU codrug was determined in a rabbit model that simulates human PVR. Intravitreal levels of triamcinolone and 5-fluorouracil were measured at different time points and drug release in vitro was tested. Toxic effects were evaluatedby electroretinograpy, clinical examination, and light microscopy. RESULTS: Both the severity of PVR grade and the percentage of eyes with moderate or worse tractional detachment were significantly less in eyes treated with the codrug. The therapeutic effect of the intravitreal codrug was paralleled by sustained intravitreal levels of triamcinolone and 5-fluorouracil. There were no drug-related toxic effects evident on clinical or histopathologic examination of eyes containing the TA/5-FU codrug. CONCLUSIONS: The intravitreal sustained-release TA/5-FU codrug effectively inhibits the progression of PVR in a rabbit model that closely resembles PVR in humans. The TA/5-FU codrug may simultaneously target different components of the wound-healing response.

Animals↗
PubMed1998

Up-regulated expression of decay-accelerating factor (CD55) confers increased complement resistance to sprouting neural cells.

We studied gene expression in relation to induced neural differentiation in a human neural crest-derived cell line, Paju. Messenger RNA isolated before and after treatment with phorbol 12-myristate 13-acetate was analyzed by differential display reverse transcription PCR. A strongly up-regulated expression of decay-accelerating factor (DAF, CD55) was found to parallel the induced neural sprouting while the expression of two other complement regulatory proteins (CD59/protectin, CD46/membrane cofactor protein) remained unaltered during neural differentiation. The increased membrane expression of DAF, which was also seen on neural processes and growth cones, conferred elevated resistance to complement-mediated lysis. Our findings suggest that in sprouting neurons DAF expression is up-regulated to provide additional complement resistance to pathfinding axons/dendrites invading new environment. It is also suggested that membrane expression of DAF may constitute a marker of growing and regenerating neurons.

CD55 Antigens↗
PubMed1998

I-2190A is a potent immunosuppressive drug for vascularized heart transplantation in rats.

The effect of a new immunosuppressant-I-2190A was tested in a rodent heart allograft model. Grafts were transplanted to recipients heterotopically. There were 5 groups: group 1 received no immunosuppressive agents; group 2 was given CsA (2.0 mg/kg, i.p.); group 3 was administered I-2190A (0.1 mg/kg, i.p.) in carboxymethyl cellulose (CMC); group 4 received injection of I-2190A (0.5 mg/kg, i.p. in CMC); group 5 received the combination treatment of I-2190A (0.1 mg/kg) and CsA (2.0 mg/kg). Immunosuppressants were discontinued 14 days after operation. No statistically significant difference in grafts median survival time (MST) was found between group 2 (9.5 days) and group 1 (9 days). The MSTs of grafts in group 3 (22 days, P < 0.05), group 4 (> 100 days, P < 0.01) and group 5 (> 100 days, P < 0.01) were significantly prolonged compared with control group 1 (9 days). Our results suggest that I-2190A is a potent immunosuppressant able to significantly prolong heart allograft survival in rats after a short time treatment, Low-dose I-2190A could potentiate the effect of sub-therapeutic dose of CsA as well.

Animals↗
PubMed1998

High expression of stanniocalcin in differentiated brain neurons.

Stanniocalcin (STC) is a glycoprotein hormone first found in fish, in which it regulates calcium homeostasis and protects against hypercalcemia. Human and mouse stc cDNA were recently cloned. We found a dramatically upregulated expression of STC during induced neural differentiation in a human neural crest-derived cell line, Paju. Immunohistochemical staining of sections from human and adult mouse brain revealed abundant presence of STC in the neurons with no activity in the glial cells. STC expression was not seen in immature brain neurons of fetal or newborn mice. Given that STC has been found to regulate calcium/phosphate metabolism in some mammalian epithelia, we suggest that STC may act as a regulator of calcium homeostasis in terminally differentiated brain neurons.

Animals↗