Biomedical subjects

Qing Li

Publications and source records attributed to Qing Li.

187 records · Page 11Linked to original sources

PubMed2002

Diabetes-induced dysfunction of the glutamate transporter in retinal Müller cells.

PURPOSE: A decrease in the ability of Müller cells to remove glutamate from the extracellular space may play a critical role in the disruption of glutamate homeostasis that occurs in the diabetic retina. Because this amino acid is toxic to retinal neurons and is likely to exacerbate oxidative stress, elucidation of the mechanisms by which glutamate levels are elevated in diabetes may help in the understanding of the pathogenesis of diabetic retinopathy. This study tested the hypothesis that the function of the glutamate transporter in Müller cells of the diabetic retina is compromised by a mechanism involving oxidation. METHODS: Müller cells were freshly isolated from normal rats and those made diabetic by streptozotocin injection. The activity of the Müller cell glutamate transporter, which is electrogenic, was monitored by the perforated-patch configuration of the patch-clamp technique. RESULTS: Four weeks after the onset of hyperglycemia, a significant dysfunction of the Müller cell glutamate transporter was detected. After 13 weeks of streptozotocin-induced diabetes, the activity of this transporter was decreased by 67%. Consistent with oxidation's causing this dysfunction, exposure to a disulfide-reducing agent rapidly restored the activity of the glutamate transporter in Müller cells of diabetic retinas. CONCLUSIONS: Early in the course of diabetic retinopathy, the function of the glutamate transporter in Müller cells is decreased by a mechanism that is likely to involve oxidation.

Amino Acid Transport System X-AG↗

PubMed2002

[Phase III clinical study of a new anticancer drug atofluding].

BACKGROUND & OBJECTIVE: Atofloding (ATFU) is a new derivative of 5-fluorouracil. The phase I and II clinical study have been finished. The current study was a phase III clinical trail of ATFU. The aim of this study was to evaluate the efficacy, toxicity of ATFU combination chemotherapy and compare with ftorafur (FT-207) in patients with gastric cancer, colorectal, esophageal cancer, and liver cancer. METHODS: A multicenter, open randomized controlled trial was carried out. A total of 320 patients with gastric cancer, colorectal, esophageal cancer and liver cancer were randomized into ATFU group (study group) and FT207 group (control group) (a ratio of 2:1), treated with MMC + VP-16 + ATFU (FT-207), DDP + HCPT + ATFU (FT-207), DDP + VDS + ATFU (FT-207), and ADM + MMC + ATFU (FT-207) regimen, respectively. The same dosage of combine drugs were used in the two groups. RESULTS: The response rates of the study group (213 cases) and the control group (107 cases) were 17.1% and 7.9% in gastric cancer (P > 0.05), 16.7% and 9.4% in colorectal cancer (P > 0.05), 20.0% and 24.6% in esophageal cancer (P > 0.05), 5.0% and 9.0% in liver cancer (P > 0.05), respectively. The major adverse effects were mylosuppression and gastrointestinal reactions which frequency and intensity had no statistical difference in the two groups. CONCLUSION: ATFU combination chemotherapy is effective and similar to FT207 in the efficiency and adverse effects for treatment of advanced GI cancers.

Adult↗

PubMed2002

[Evaluation of TGF-beta1 expressed by oral and maxillofacial malignant neoplasm].

OBJECTIVE: To investigate the relationship between the level of transforming growth factor beta I(TGF-beta(1)) in oral and maxillofacial malignant neoplasms and the biological characteristics of these carcinoma cells. METHODS: The level of TGF-beta(1) in the carcinoma tissue cells, human tongue squamous cell carcinoma cell line Tca8113, human minor salivary gland carcinoma cell line ACC-2 and highly metastatic adenoid cystocarcinoma cell line ACC-M was measured by ELISA KIT. RESULTS: The level of TGF-beta(1) in the carcinoma tissue cells had significant difference to that of normal cells(P<0.01). The level in Tca8113 and ACC-2 cells was significantly higher(P<0.05). Squamous cell carcinoma cell line Tca8113 had the same level of TGF-beta(1) as the adenoid cystocarcinoma cell line ACC-2, but the highly metastatic adenoid cystocarcinoma cells(ACC-M) expressed far less compared to ACC-2 cells (P<0.01). The level of TGF-beta(1) secreted by ACC-M cells to the culture without serum was also lower than that of any of the other carcinoma cells or normal cells. CONCLUSION: The level of TGF-beta(1) expression had significant relation to the proliferation, invasion and metastasis of oral and maxillofacial malignant neoplasms.

English Abstract↗

PubMed2002

The influence of central corneal thickness and corneal curvature and axial length on the measurement of intraocular pressure.

PURPOSE: To examine the influence of central corneal thickness (CCT), corneal curvature (CC), and axial length (AL) on intraocular pressure (IOP). METHODS: Eighty-one clinically normal eyes were included in our study. The IOP, CCT, CC, AL were measured using a Goldmann applanation tonometer, optical pachymeter, keratometer and A-scan ultrasound biometer respectively in all subjects. RESULTS: A highly significant positive correlation was identified between IOP and CCT. Linear regression analysis suggests that an increase in CCT of 0.010 mm is associated with a 4.946 mmHg increment in IOP. No significant positive correlation was identified between IOP and CC. P values are 0.724 and 0.414 respectively for vertical and horizontal readings. A paradoxically reversed correlation was present between IOP and axial length. CONCLUSION: Corneal thickness is a very important confounding factor in the measurement of intraocular pressure, which warrants further attention in our clinical practice.

Adolescent↗

PubMed2002

[The surface treatment of artificial joint metal materials].

The surface treatment method for improving the functions of artificial joint metal materials and its properties have been sketched out in this paper. The purpose and the method of ceramic materials for coating and metal surface pre-treatment are explained and we have also discussed the bioactive ceramic coating and its function.

Ceramics↗

PubMed2001

The protein SET binds the neuronal Cdk5 activator p35nck5a and modulates Cdk5/p35nck5a activity.

The neuronal Cdk5 kinase is composed of the catalytic subunit Cdk5 and the activator protein p35(nck5a) or its isoform, p39(nck5ai). To identify novel p35(nck5a)- and p39(nck5ai)-binding proteins, fragments of p35(nck5a) and p39(nck5ai) were utilized in affinity isolation of binding proteins from rat brain homogenates, and the isolated proteins were identified using mass spectrometry. With this approach, the nuclear protein SET was shown to interact with the N-terminal regions of p35(nck5a) and p39(nck5ai). Our detailed characterization showed that the SET protein formed a complex with Cdk5/p35(nck5a) through its binding to p35(nck5a). The p35(nck5a)-interacting region was mapped to a predicted alpha-helix in SET. When cotransfected into COS-7 cells, SET and p35(nck5a) displayed overlapping intracellular distribution in the nucleus. The nuclear co-localization was corroborated by immunostaining data of endogenous SET and Cdk5/p35(nck5a) from cultured cortical neurons. Finally, we demonstrated that the activity of Cdk5/p35(nck5a), but not that of Cdk5/p25(nck5a), was enhanced upon binding to the SET protein. The tail region of SET, which is rich in acidic residues, is required for the stimulatory effect on Cdk5/p35(nck5a).

Amino Acid Sequence↗

PubMedDate not supplied

Capillary leak syndrome in children with C4A-deficiency undergoing cardiac surgery with cardiopulmonary bypass: a double-blind, randomised controlled study.

BACKGROUND: Capillary leak syndrome is a life-threatening complication after cardiopulmonary bypass (CPB), with an incidence of about 4-37% in children worldwide. On the basis of previous results, we undertook a randomised controlled study to investigate the priming with plasma rich in the C4A isotype of complement component 4 on the incidence of capillary leak syndrome in children with C4A deficiency. METHODS: In a hospital in Wuhan, China, we randomly assigned 116 neonates, infants, and children lacking complement component C4A to receive C4A-free or C4A-rich plasma priming (n=58 each, 20 mL/kg). The primary outcome was capillary leak syndrome, identified as an increased transvascular escape rate of Evans blue dye from plasma. Concentrations of activated complement components C4 and C3, inflammatory mediators interleukin 6, interleukin 8, tumour necrosis factor (TNF) alpha, plasma protein, and PaO2/F(I)O2 ratios (ratio of the partial arterial pressure of oxygen to the fractional concentration of oxygen in inspired air) were measured before and 4 h after CPB. Analysis was by intention to treat. FINDINGS: Three (5%) patients given C4A-rich plasma priming had capillary leak syndrome compared with 56 (97%) given C4A-free plasma (p<0.0001). At 4 h after CPB, activated C4, interleukin 6, interleukin 8, and TNFalpha concentrations were higher, whereas PaO2/F(I)O2 ratios and plasma protein concentrations were significantly lower in the C4A-free group than changes in the C4A-rich group. Activated C3 rose equally in both groups. Activated C4 significantly correlated with interleukin 6, interleukin 8, and TNFalpha concentrations; PaO2/F(I)O2 ratios; and the escape rate of Evans blue dye at 4 h after CPB. Two patients in the C4A-free group died of respiratory and renal failure on day 3 after CPB. INTERPRETATION: In paediatric patients with C4A deficiency, C4A-rich plasma priming reduces the incidence of CPB-related capillary leak syndrome by blocking the activated C4 increase and attenuating the systemic inflammatory response after CPB.

Capillary Leak Syndrome↗