Biomedical subjects

Q Zhu

Publications and source records attributed to Q Zhu.

At least 145 records · Page 8Linked to original sources

PubMed1999

Proliferative activity as detected by immunostaining with Ki-67 and proliferating cell nuclear antigen in benign and malignant epithelial lesions of the human parotid gland.

OBJECTIVE: A retrospective immunohistochemical study of parotid gland lesions was designed to evaluate the diagnostic and prognostic value of the proliferating cell nuclear antigen (PCNA) and Ki-67 with monoclonal antibodies PC 10 and MIB-1, respectively. STUDY DESIGN: Tissue samples comprised normal parotid gland (N, n = 10), chronic sialadenitis (CS, n = 8), Warthin's tumor (W, n = 10), benign pleomorphic adenoma (BPA, n = 8), mucoepidermoid carcinoma (MEC, n = 13), carcinoma in pleomorphic adenoma (CPA, n = 8) and adenoid cystic carcinoma (ACC, n = 12). The morphometric parameters for PCNA and MIB-1 comprised the PI and MI labelling indices (the numerical percentage of positive nuclei), NAP and NAM (the numerical density of positive nuclei), and NPI and NMI (volume corrected index). RESULTS: The values of MIB-1 parameters increased progressively in benign lesions in comparison with the N group and in malignant neoplasms in comparison with nonneoplastic groups and benign lesions. Values for all parameters in BPA were significantly lower than those in malignant groups. Spearman rank correlation analysis showed a highly positive correlation between the morphometric parameters and severity of the lesions. The mean values of MI and NMI were significantly higher in patients who died of the malignant tumors than in those who survived. The same quantitative parameters for PCNA did not differ significantly from those obtained for MIB-1 and showed similar trends. CONCLUSION: PCNA and MIB-1 indices are reliable markers for discriminating between benign and malignant tumors of the parotid gland, and the parameters PI, MI, NPI and NMI may have prognostic applications.

Adenocarcinoma↗

PubMed1999

Effects of BRL 55 834 on allergen-induced bronchoconstriction and airway inflammation in sensitized guinea pigs.

OBJECTIVE: To investigate the effects of potassium channel activator on allergen-induced bronchoconstriction and airway inflammation and to discuss which role it plays in asthma therapy. METHODS: Airway insufflation pressure, examination of inflammatory cells in bronchial alveolar lavage fluid, analysis of airway pathology and airway Evans blue dye extravasation measurement were employed to detect airway resistance and airway inflammatory responses. RESULTS: [(3s, 4R)-3, 4-dihydro-2, 2-dimethyl-4-(2-oxopiperidin-l-yl)-6-pentafluoroethyl-2H-1-benzopyran-3-ol] (BRL) 55 834 (8 micrograms/kg) inhibited not only ovalbumin-induced airway insufflation pressure increase but also inflammatory cell infiltration (ICI) in sensitized guinea-pigs; moreover, it did not decrease blood pressure; in contrast to BRL 55 834, single dose of BRL 38 227 (200 micrograms/kg) and verapamil (0.5 mg/kg) had a little effect on ICI; single dose of aminophylline (25 mg/kg) and dexamethasone (1 mg/kg) could not inhibit ICI, but the former could inhibit airway insufflation increase; drugs, besides aminophylline, could reduce microvascular leakage; single dose of BRL 38 227, verapamil and dexamethasone had no inhibition of airway insufflation pressure; BRL 38 227 and verapamil decreased blood pressure markedly. CONCLUSIONS: Selective potassium channel activator BRL 55 834 not only decreases airway resistance, but also inhibit airway inflammation, and both of them are of benefit to asthma therapy.

Animals↗

PubMed1999

[Preoperative staging of patients with primary ovarian carcinoma by CT and MRI].

OBJECTIVE: To investigate values and limitations of CT and MRI applied in staging of patients with primary ovarian carcinoma (POC). METHODS: Forty two patients with POC proven by radical surgery, laparotomy, and postoperative pathology were studied. In comparison to surgical and pathological findings, sensitivity, specificity, and accuracy of CT, MRI and CT plus MRI were calculated. Staging by the three imaging methods was obtained according to FIGO's classification. RESULTS: CT and MRI showed higher accuracy in evaluation of invasion to uterus (89.5% and 94.7%) and disease of Douglas pouch (94.7% and 97.4%). CT was to some extent superior to MRI in assessing ipsilateral or bilateral tumor and lesions related to peritoneal seeding; MRI, however, had better capability of diagnosing invasion to ovarian capsule, pelvic organs excluding bowel, nodules in Douglas pouch, and metastasis to lymph nodes. The overall accuracy of staging by CT, MRI, and CT plus MRI was 73.7%, 68.4%, and 70.6%, respectively (P > 0.05). CONCLUSION: CT and MRI are useful imaging modalities in staging of POC, but low sensitivity for detecting involvement in some anatomic regions needs to be improved.

Adult↗

PubMed1999

[Clinical observation of side effects of Tripterygium preparation].

OBJECTIVE: To observe the side effects of Tripterygium preparation (TP) in the course of treatment. METHODS: Two hundred and seventy-one cases of patients with rheumatoid arthritis (RA) were treated using various TP to observe the occurrence of adverse reaction. RESULTS: The influence on reproductive system with TP extracted from the leaf ester tab were less than that from the root (TP tab and TP multiglycoside tab, TPMG). In group of TPMG the rate of side effect of 60 mg daily dosage was more than 30 mg daily (P < 0.01). The main influence on digestive tract and irregular menstruation was before age of 50 years and on renal function was after age of 50 years. Those adverse reactions mainly occur within first ten years in long therapy period. The side effects of TPMG produced in the Dampness-Heat type of RA were lower than Yin-Deficiency of Liver and Kidney type of RA (P < 0.05). CONCLUSION: TP ester tab is available for young woman and TPMG tab is suitable for the Dampness-Heat type of RA with lower dosis maintenance therapy.

Adult↗

PubMed1999

[The effect of sandostatin on sphincter of Oddi in acute severe pancreatitis in dogs].

OBJECTIVE: To study the pressure change of sphincter of Oddi (SO) in acute severe pancreatitis (ASP) and the effect of sandostatin on it. METHODS: Fifteen dogs were used and allocated into 2 groups: ASP untreated group and sandostatin group. The ASP model was prepared by retrograde ductal injection of a mixture of 5% taurocholic acid and autologous bile. SO manometic parameters including basal pressure (BP) and phasic contraction amplitude (PCA) were measured at each time spot before and after the preparation of ASP and after the administration of sandostatin. RESULTS: BP was obviously increased after ASP preparation and sandostatin could significantly decrease the BP of SO in ASP group but not PCA. CONCLUSION: Dysmotility of SO might play an important role in the severity and progression of ASP. Sandostatin may have beneficial effects in the treatment of ASP by decreasing BP of SO.

Acute Disease↗

PubMed1999

[Biomechanical evaluation of five fixation techniques for the lower cervical spine].

OBJECTIVE: This study biomechanically investigated the three-dimensional motion stability of five reconstruction methods in the cervical spine, in order to provide the biomechanical basis for the clinical selection of fixation methods. METHODS: With eight adult cervical spine fresh specimens, the three-column injury was produced at C(4 - 5) level. The spinal constructs, reconstructed by various techniques including anterior titanium locking screw plate (TLSP), posterior interspinous wiring (IW), combined fixation with the TLSP and IW (TLSP + IW), Roy-Camille plate (RP), and transpedicular screw plate (TP), were tested under six loading modes-flexion, extension, right/left lateral bending, and right/left axial rotation. RESULTS: The three-dimensional motion stability of either TLSP or IW was less than that of intact cervical spine. The TLSP + IW and RP provided increased stability compared with the intact spine. The stabilizing capabilities of transpedicular screw plate fixation was the best in all loading modes. CONCLUSIONS: In three-column instability of cervical spine injury, exclusive use of the anterior plate or the posterior interspinous wiring was not supported by the results. The stabilizing capabilities provided by combined anterior and posterior instrumentation and posterior plate were good. The three-column fixation for the cervical spine using transpedicular screw plate fixation offers increased stability significantly over that of other conventional cervical fixation systems.

Adult↗

PubMed1999

[The complications of excimer laser in-situ keratomileusis for myopia].

OBJECTIVE: To analyze the complications of excimer laser in-situ keratomileusis (LASIK) for myopia, investigate the causes and discuss the prevention of these complications. METHODS: The SCMD microkeratome and Schwind Keratom F excimer laser were used to correct myopia on 1,265 eyes in 662 cases. The eyes were divided into 3 groups: A: -10.00 D, 252 eyes. All of them were followed up for a period of 12 months. RESULTS: Intraoperative corneal disk completely detached: 6 eyes (0.5%); corneal disk incomplete sectioned: 3 eyes (0.2%); corneal epithelial disk: 2 eyes (0.2%); corneal interface minute foreign metal bodies: 11 eyes (0.9%); postoperative steroid intraocular hypertension: 21 eyes (1.7%); macular hemorrhage: 2 eyes (0.2%). At postoperative 3 months, there was refractive regression > 1.00 D in 0.0%, 3.1% and 7.9% respectively in the 3 groups; the increase in astigmatism > 1.00 D, 0.4%, 2.8% and 4.4% respectively. CONCLUSION: LASIK is a safe effective method for correcting myopia. Yet attention should be paid on the complications during and after operation. With the improvement in operative technique and better designed procedure, these complications can be decreased and the preoperative correctness in estimation of the postoperative results and the postoperative accuracy in the correction of myopia can be elevated.

Adolescent↗

PubMed1999

[Effects of vitamin A deficiency on the development and growth of rat embryos].

Effects of vitamin A deficiency on the development and growth of rat embryos were studied. Serious vitamin A deficiency markedly reduce body weight, body length and tail length, and induce incomplete development of skeleton and induce pathological change of brain and kidney of rat fetus. It was concluded that the development and growth of the embryos was affected and the brain and the kidney of fetus were damaged in serious vitamin A deficient rats.

Animals↗

PubMed1999

[Detection of 8-hydroxyguanine in the DNA of the H2O2-treated HL-60 cells by GC/FID].

This paper describes the DNA damage by hydrogen peroxide in HL-60 cells and the detection of 8-hydroxyguanine produced. The number of cells was at least about 2 x 10(7)/sample. Treatment of HL-60 cells with 0.4 mmol/L hydrogen peroxide for 24 h would result in DNA damage. The DNA samples were isolated, then qualitatively and quantitatively analyzed before hydrolysis. The results of experiments showed that 100-300 microL 98% formic acid could hydrolyze about 0.12 mg DNA samples completely in 150 degrees C for 1 h. After lyophilizing the DNA samples for 6-8 h, one DNA sample was trimethylsilylated completely with 150 microL BSTFA in 150 degrees C for 1 h. The recovery of trimethylsilylated 8-hydroxyguanine was 81.70%. The trimethylsilylated 8-hydroxyguanine was identified by GC/FID and CGC/MS-SIM parallely.

Chromatography, Gas↗

PubMed1999

[Detection of human papillomavirus gene in biopsies from colon carcinoma by PCR].

OBJECTIVE: To detect the human papillomavirus gene (HPVs) in biopsies from colon carcinoma by PCR and to study the relationship between HPV infection and colon carcinoma. METHODS: 46 biopsies from colon carcinoma, 10 biopsies from tissue around carcinoma and 16 control biopsies were collected and DNA were extracted. The HPV DNA in biopsies were amplified by PCR using general primers (GP) and primers for HPV6/11, HPV16/33 and HPV18. RESULTS: 20 out of 46 biopsies from colon carcinoma showed HPV gene positive, HPV6/11, HPV6/33 and HPV18 positivity were 3, 11 and 6 respectively. HPV DNA was found in 1 case from 10 biopsies of surrounding tissue of carcinoma. 16 control biopsies were negative. CONCLUSION: HPV may be related to the etiology of colon carcinoma.

Colorectal Neoplasms↗

PubMed1999

Evolutionary relationships among seventeen human papillomavirus genotypes.

The DNA and the protein sequences of the six major open reading frames (ORFs) of 17 human papillomavirus (HPV) genotypes have been carefully aligned. Conserved primary and probable secondary structural features of the proteins have been identified. From the analysis of variations in the aligned positions, the most consistent evolutionary relationships have been reconstructed for each gene and for the genomes as a whole. The L1 gene encoding the major capsid protein and the E1 gene encoding a replication protein are the most conserved. The hinge region in E2 is the most divergent. With varying degrees of sequence relatedness, the major groups and subgroups of HPV genotypes can be recognized, these clusters: the mucosotrophic virus types (33, 58), (16, (31, 35)), (18, 39), (51), (6b, 11); mucosal/cutaneous transitional virus types (2a, 57); and the cutaneous virus types (47, (5, 8)), (1a), (41), closely reflect epithelial tissue-type predilections and clinical pathogenicities.

Amino Acid Sequence↗

PubMed1999

[Joint rotational analysis of twenty six bands of the H2(80) Se molecule].

This paper expressed the theory of Global fit model. Global fit of all known up today rotation-vibration energies of twenty four states of the H2(80) Se molecule had been made, and the corresponding set of 112 parameters, which reproduce the initial 3516 upper energies with the mean accuracy of 10.6 x 10(-3) cm(-1), were obtained. On this base fine rotational structures of the local-mode bands (500, A1) and (401, B2) were analyzed with 252 upper energies, which were analyzed in the normal-molde and local-mode also. In the end, with the results above, joint rotation-vibration energies of twenty six states of H2(80) Se molecule were made, and the corresponding set of 114 parameters obtained, which reproduce the initial 3768 upper energies with the mean accuracy of 9.62 x 10(-3) cm(-1).

English Abstract↗

PubMed1998

Comparison of the strengths of lumbosacral fixation achieved with techniques using one and two triangulated sacral screws.

STUDY DESIGN: The strength of sacral screw fixation achieved with techniques using one sacral screw and two triangulated sacral screws with Chopin block was tested on 10 fresh human sacrum specimens. OBJECTIVES: To compare the stiffness and the failure strength of single sacral screw fixation and those of two divergent triangulated sacral screw fixation under different loading conditions. SUMMARY OF BACKGROUND DATA: Weak sacral screw fixation is the major cause of failure in instrumented lumbosacral fusion. Although previous studies have evaluated the strength of anteromedially and anterolaterally inserted sacral screws, the strength of two divergent triangulated sacral screws has not been evaluated biomechanically. It is assumed that increasing the number of sacral screws and using a triangulated insertion technique may increase the strength of purchase for lumbosacral fixation. METHODS: Ten fresh human sacrum specimens were used in this study. Six specimens were from donors less than 30 years of age (younger group), and the other four were from donors more than 60 years of age (aged group). The specimens were assigned randomly to either one side one S1 pedicle screw inserted anteromedially or to the other side with two screws directed anteromedially and anterolaterally. All specimens were tested with an Instron material testing machine (Instron Limited, High Wycombe, England). The average stiffness under compression, tension, and torsion were calculated from the average slopes of the load deformation curves. The failure load was applied for the final testing. RESULTS: The results showed significant differences in stiffness between fixation with one screw and fixation with two divergent triangulated screws. With one S1 pedicle screw fixation, the average stiffness was 203 N/mm for compression, 147 N/mm for tension, and 2 Nm/degree for torsion. With two-screw fixation the average stiffness increased to 255 N/mm (126%), 185 N/mm (126%) and 2.4 Nm/degree (120%), respectively. The average failure strength under tension loads was found to be 1450 N in the younger specimens and was reduced to 980 N in the aged specimens. CONCLUSION: This study showed that fixation with two divergent triangulated screws to the sacrum was significantly stronger than one-screw fixation for lumbosacral fusion. The strength of fixation seems to have a negative correlation with aging.

Adult↗

PubMed1998

Transforming growth factor beta signaling through Smad1 in human breast cancer cells.

Previous results have suggested that Smad1 transduces signals in response to bone morphogenetic proteins (BMPs), but not in response to transforming growth factor beta (TGF-beta). Here we investigated the ability of TGF-beta to regulate Smad1 phosphorylation, hetero-oligomerization with Smad4, translocation to the nucleus, and transcriptional activation of 3TP-luciferase reporter activity in TGF-beta- and BMP-responsive Hs578T human breast cancer cells. We demonstrate that Smad1 was rapidly phosphorylated in vivo in response to both TGF-beta3 and BMP2 as determined using an antibody against the epitope-tagged Smad1 being expressed. In addition, both TGF-beta3 and BMP2 increased Smad1-Smad4 hetero-oligomerization in Hs578T cells. Visualization of Smad1 nuclear translocation with the aid of green fluorescent protein (GFP) in live cells demonstrated nuclear accumulation of GFP-Smad1 fluorescence in response to either TGF-beta or BMP2 stimulation. After ligand stimulation, approximately 60-70% of transfected cells displayed prominent nuclear fluorescence. Expression of Smad1 in Hs578T cells increased the activity of the TGF-beta-responsive reporter 3TP-Lux. Moreover, TGF-beta treatment further potentiated the effect of Smad1 on 3TP-luciferase activity. Collectively, our results demonstrate that TGF-beta as well as BMP can signal through Smad1.

Animals↗

PubMed1998

Disruption of the NF-H gene increases axonal microtubule content and velocity of neurofilament transport: relief of axonopathy resulting from the toxin beta,beta'-iminodipropionitrile.

To investigate the role of the neurofilament heavy (NF-H) subunit in neuronal function, we generated mice bearing a targeted disruption of the gene coding for the NF-H subunit. Surprisingly, the lack of NF-H subunits had little effect on axonal calibers and electron microscopy revealed no significant changes in the number and packing density of neurofilaments made up of only the neurofilament light (NF-L) and neurofilament medium (NF-M) subunits. However, our analysis of NF-H knockout mice revealed an approximately 2.4-fold increase of microtubule density in their large ventral root axons. This finding was further corroborated by a corresponding increase in the ratio of assembled tubulin to NF-L protein in insoluble cytoskeletal preparations from the sciatic nerve. Axonal transport studies carried out by the injection of [35S]methionine into spinal cord revealed an increased transport velocity of newly synthesized NF-L and NF-M proteins in motor axons of NF-H knockout mice. When treated with beta,beta'-iminodipropionitrile (IDPN), a neurotoxin that segregates microtubules and retards neurofilament transport, mice heterozygous or homozygous for the NF-H null mutation did not develop neurofilamentous swellings in motor neurons, unlike normal mouse littermates. These results indicate that the NF-H subunit is a key mediator of IDPN-induced axonopathy.

Actin Cytoskeleton↗

PubMed1998

Protective effect of neurofilament heavy gene overexpression in motor neuron disease induced by mutant superoxide dismutase.

To investigate the role of neurofilaments in motor neuron disease caused by superoxide dismutase (SOD1) mutations, transgenic mice expressing a amyotrophic lateral sclerosis-linked SOD1 mutant (SOD1(G37R)) were mated with transgenic mice expressing human neurofilament heavy (NF-H) subunits. Unexpectedly, expression of human NF-H transgenes increased by up to 65%, the mean lifespan of SOD1(G37R) mice. Microscopic examination corroborated the protective effect of NF-H protein against SOD1 toxicity. Although massive neurodegeneration occurred in 1-yr-old mice expressing SOD1(G37R) alone, spinal root axons and motor neurons were remarkably spared in doubly SOD1(G37R);NF-H-transgenic littermates.

Amyotrophic Lateral Sclerosis↗

PubMed1998

Absence of neurofilaments reduces the selective vulnerability of motor neurons and slows disease caused by a familial amyotrophic lateral sclerosis-linked superoxide dismutase 1 mutant.

Mutations in superoxide dismutase 1 (SOD1), the only proven cause of amyotrophic lateral sclerosis (ALS), provoke disease through an unidentified toxic property. Neurofilament aggregates are pathologic hallmarks of both sporadic and SOD1-mediated familial ALS. By deleting NF-L, the major neurofilament subunit required for filament assembly, onset and progression of disease caused by familial ALS-linked SOD1 mutant G85R are significantly slowed, while selectivity of mutant-mediated toxicity for motor neurons is reduced. In NF-L-deleted animals, levels of the two remaining neurofilament subunits, NF-M and NF-H, are markedly reduced in axons but are elevated in motor neuron cell bodies. Thus, while neither perikaryal nor axonal neurofilaments are essential for SOD1-mediated disease, the absence of assembled neurofilaments both diminishes selective vulnerability and slows SOD1(G85R) mutant-mediated toxicity to motor neurons.

Amyotrophic Lateral Sclerosis↗

PubMed1998

Cancer gene therapy by direct tumor injections of a nonviral T7 vector encoding a thymidine kinase gene.

Previously, we described a nonviral cytoplasmic gene therapy vector system based on the T7 autogene concept. This system has been shown to achieve rapid and high levels of gene expression in a variety of animal cells and tissues. To test the utility of the system in vivo tumor ablation, a T7 cancer gene therapy plasmid vector, pT7T7/T7TK, was constructed. This nonviral vector contains a T7 autogene, T7T7, and a human herpes simplex virus thymidine kinase (HSV-TK) gene driven by a second T7 promoter (T7TK). When co-transfected with T7 RNA polymerase (T7 RNAP) into cultured human osteosarcoma 143B cells, abut 10-20% of the cells were found to express HSV-TK, and more than 90% of the cells were killed in the presence of 1 microM ganciclovir (GCV) within 4 days after DNA transfection. The increase in killing above the transfection frequency is due to a "bystander" effect among transfected and untransfected 143B cells. Direct injections of pT7T7/T7TK into 143B tumors grown in nude mice resulted in TK gene expression in tumor cells located near the injection sites as revealed by the immunohistochemical staining. Repeated tumor injections of the pT7T7/T7TK vector and intraperitoneal (i.p.) injections of GCV resulted in inhibition of tumor growth and in tumor shrinkage in 6 out of 10 treated nude mice. Three of those six tumors fully regressed shortly after the end of the GCV injections. All of the full tumor regressions were found to be permanent and no apparent tumor relapses were observed for the rest of the lives of the treated nude mice after the initial tumor ablations. These results, combined with the nonviral and rapid cytoplasmic gene expression features, suggest that the T7 vector may be a good candidate for cancer gene therapy and other medical and biological applications.

Animals↗