Search PubMed⌕ Search

Biomedical subjects

Q Ye

Publications and source records attributed to Q Ye.

At least 181 records · Page 10Linked to original sources
PubMed1994

Intracellular Ca2+ and Ca(2+)-binding proteins in chemically transformed rat fibroblasts.

Disturbed Ca2+ handling and altered levels of Ca(2+)-binding proteins (CaBPs) have been found in many transformed cells. To investigate whether there exists a correlation between expression of CaBPs and intracellular Ca2+ we analyzed three transformed rat fibroblast cell lines (T14, T10, and T43) exhibiting different levels of CaBPs. All three cell lines express calmodulin (CaM) at elevated levels compared to normal tissues. In addition, oncomodulin (OM) is expressed at high levels in T14 cells and at much lower levels in T10 cells, while T43 cells do not express OM. We demonstrate that CaBP levels are affected by changes of extracellular [Ca2+] ([Ca2+]o). In reduced [Ca2+]o, CaM levels were increased up to 60%, while OM levels were decreased up to 65% in T14 and T10 cells. Increase of [Ca2+]o, on the other hand, led to a decrease of CaM levels and an increase of OM levels, suggesting that [Ca2+]o exerts its effect on OM and CaM differently. Comparison of the growth rates in reduced [Ca2+]o revealed that T14 cells with the most pronounced CaM increase induced by low [Ca2+]o grew best under these conditions. These results indicate that elevated CaM expression but not the presence of OM reduces the Ca2+ requirement for growth. Intracellular [Ca2+] transients are not buffered by the high concentration of CaBPs in T14 cells. In contrast, [Ca2+]i transients induced by increase of [Ca2+]o or addition of serum were most pronounced in T14 cells compared to T10 and T43 cells.

Animals↗
PubMed1994

Effects of voltage perturbation of the lingual receptive field on chorda tympani responses to Na+ and K+ salts in the rat: implications for gustatory transduction.

Taste sensory responses from the chorda tympani nerve of the rat were recorded with the lingual receptive field under current or voltage clamp. Consistent with previous results (Ye, Q., G. L. Heck, and J. A. DeSimone. 1993. Journal of Neurophysiology. 70:167-178), responses to NaCl were highly sensitive to lingual voltage clamp condition. This can be attributed to changes in the electrochemical driving force for Na+ ions through apical membrane transducer channels in taste cells. In contrast, responses to KCl over the concentration range 50-500 mM were insensitive to the voltage clamp condition of the receptive field. These results indicate the absence of K+ conductances comparable to those for Na+ in the apical membranes of taste cells. This was supported by the strong anion dependence of K salt responses. At zero current clamp, the potassium gluconate (KGlu) threshold was > 250 mM, and onset kinetics were slow (12 s to reach half-maximal response). Faster onset kinetics and larger responses to KGlu occurred at negative voltage clamp (-50 mV). This indicates that when K+ ion is transported as a current, and thereby uncoupled from gluconate mobility, its rate of delivery to the K+ taste transducer increases. Analysis of conductances shows that the paracellular pathway in the lingual epithelium is 28 times more permeable to KCl than to KGlu. Responses to KGlu under negative voltage clamp were not affected by agents that are K+ channel blockers in other systems. The results indicate that K salt taste transduction is under paracellular diffusion control, which limits chemoreception efficiency. We conclude that rat K salt taste occurs by means of a subtight junctional transducer for K+ ions with access limited by anion mobility. The data suggest that this transducer is not cation selective which also accounts for the voltage and amiloride insensitive part of the response to NaCl.

4-Aminopyridine↗
PubMed1994

Patella and patellofemoral resurfacing (37 cases report).

Chondromalacia and patellofemoral osteoarthritis are common diseases that cause pain and disablement of the knee. Conservative therapy is not always effective. Since 1983 we have used isolated polyethylene patellar prosthesis for patella resurfacing of 19 patients with patellofemoral osteoarthritis. After an average of 44.9 months follow-up, we found the treatment was not as satisfactory as earlier trials. The main reason is the wide erosion of femoral condyle caused by the polyethylene patella. To overcome this shortness, we designed a new type of patellofemoral prosthesis which is named Y-L-Q. From January, 1991 to November, 1993, we used this prosthesis to treat 16 knees of 13 patients with patellofemoral osteoarthritis. Most of those patients improved both symptomatically and functionally. The good to excellent results rate was 87.5% (14/16 knees) at the time of an average 16 months follow-up. The early results of our experience with patellofemoral resurfacing are encouraging, and extended follow-ups are in progress.

Aged↗
PubMed1994

[Modified en bloc resection procedure for malignant tumor of the shoulder girdle].

En bloc resection of the shoulder girdle (Tikhoff-Linberg procedure) is a valuable limb-sparing surgical technique for bony and soft tissue malignant tumor in and around the proximal humerus and shoulder girdle. Significant amount of hand-elbow function is maintained with the procedure, and long time results in the treatment of neoplasms by this technique was found to be the same as by the method of a forequarter amputation or the shoulder disarticulation in the English literature. Four cases with malignant tumor in the shoulder girdle was treated with this modified method in our department. The average follow-up was 8 years. One case died due to another kind of tumor 6 years after operation, and other 3 cases are alive and disease free.

Adult↗
PubMed1994

Human alpha atrial natriuretic peptide fermentation by using a genetically engineered yeast strain.

The genotype of the recombinant yeast strain Y33::YFD71-3 used in this study is alpha, his, leu, ade and suc. Preliminary batch cultures in shaking flasks showed the expression level of atrial natriuretic peptide (ANP) was 1-2 mg/L. Shaking flask cultures were carried out in YG medium which contained glucose, yeast nitrogen base (YNB), and different amounts of adenine, histidine and leucine. When the growth was limited by adenine, protein secreted from Y33::YFD71-3 cells was increased obviously. Adenine became the limiting substrate when the YG medium was supplemented with 5 g/L of casamino acid (CAA) and the level of ANP expression was influenced by the concentrations of adenine, YNB and leucine in the medium. In fed batch cultures carried out in a RIBE-5 fermenter, the cultures were fed with glucose and a mixture of YNB, CAA, adenine, histidine and leucine to improve cell growth and ANP expression, and the maximum ANP concentration in the culture reached 24.8 mg/L.

Adenine↗
PubMed1994

[The use of internal fixation in the treatment of spinal tuberculosis].

We have applied debridement with grafting and internal fixation techniques (including Luque and Dick procedures) in the treatment of tuberculosis of the spine in the past few years. Analysis of 18 patients showed good prognosis after the Luque or Dick procedure. The patients are able to walk around within a few days after operation. One to five years of follow-up showed no recurrence or kyphotic deformity.

Adolescent↗
PubMed1994

[The prevention and treatment of complications with pedicle screws].

Pedicle screws are more commonly used by spinal surgeons recently. Although Roy-Camile, Dick, Steffee, R-F etc., are all different surgical procedures, all need pedicle screw techniques. Up to March 1991, 61 cases with 334 screws inserted by Steffee and Dick operations had been performed in our hospital. Neurological symptoms, among all complications, are the most serious problems associated with these procedures. By analyzing the insertion point, transverse screw angle, sagittal angle and other causes of complications of pedicle screws, we present here our experiences for prevention and treatment of these complications.

Adult↗
PubMed1994

Application of internal fixation in the treatment for tuberculosis of the spine.

This is a study of 18 patients who had surgical treatment for spinal tuberculosis. All patients were admitted with the spinal tuberculosis and treated with a combination of anterior debridement and bone graft with posterior internal fixation using the Luque or Dick technique. The patients were able to walk within a few days postoperation. Three to seven years follow-ups show no recurrence, kyphosis and/or solid fusion.

Adolescent↗
PubMed1994

[Long-term follow-up of patients with patella resurfacing].

Patellar resurfacing was performed by the authors. From 1983 to 1988, 19 cases (22 knees) with patello-femoral osteoarthritis were treated with this procedure in our hospital. Excellent and good results were recorded in 13 cases (59.1%) one year after operation, but were zero in the long-term follow-up (average 8.7 years) because of recurrent knee pain due to the wearing of the cortex of the femoral groove. Further operation was necessary for those cases, such as patellectomy or total knee replacement. Since 1991 Y-L-Q's type of patellofemoral replacement has been used in 11 cases in our department to alter the isolated resurfacing of the patella. The femoral groove was replaced with a metallic implant that allows sliding of a polyethylene patella to prevent the wearing of the femoral cortex. Preliminary results are good.

Aged↗
PubMed1994

Effect of 5' non-coding region on expression of LT-B gene.

The different construction of mRNA 5' non-coding region may affect gene expression. To improve gene expression levels, we constructed recombinant plasmids with different nucleotide composition of the 5' non-coding region which direct the synthesis of human toxicogenic E. coli heat-labile enterotoxin B subunit coded by LT-B gene under the control of the PRPL tandem promoter of vector pBV220. These recombinants were expressed in E. coli HB101 and DH5 alpha, respectively. The results show that the expression levels of LT-B gene with two tandem SD sequences upstream from the initiation codon are lower than those with only one SD sequence and translation coupling can improve the expression levels; the different SD sequences can affect the expression of LT-B gene a little. The SD sequence of LT-B gene itself may be better for expression than that of the vector pBV220; the length of 5' non-coding region in the recombinants harboring only one SD sequence has no effect on the expression of LT-B gene; the expression of LT-B gene in HB101 is higher than that in DH5 alpha.

Bacterial Toxins↗
PubMed1993

Ion pathways in the taste bud and their significance for transduction.

Taste buds share a topology with ion-transporting epithelial and evidence now indicates that neural responses in rats to Na+ salts of differing anion are mediated by both transcellular and paracellular ion transport. Na+ exerts its effects mainly on the transcellular pathway. Neural responses to Na+ salts are enhanced by negative voltage clamp and suppressed by positive clamp in a manner indicating modulation of the apical membrane potential of receptor cells. Anion effects are mainly paracellular. Under zero current clamp increasing anion size reduces the neural response at constant Na+ concentration. Below about 50 mM this difference is entirely eliminated under voltage clamp. This suggests that paracellular transepithelial potentials normally create an anion difference. At higher concentrations the relatively high permeability of the paracellular shunt to Cl- permits sufficient electroneutral diffusion of NaCl below the tight junctions to stimulate cells that do not make direct contact with the oral cavity. In general, the sensitivity of a response to perturbations in the apical membrane potential indicates that some phase of Na+ salt taste transduction is accompanied by changes in an apical membrane channel conductance.

Animals↗
PubMed1993

Voltage dependence of the rat chorda tympani response to Na+ salts: implications for the functional organization of taste receptor cells.

1. Voltage-clamp and current-clamp data were obtained from a circumscribed region of the anterior rat lingual epithelium while simultaneously monitoring the afferent, stimulus-evoked, neural response from the same receptive field. 2. Chorda tympani (CT) responses at constant Na(+)-salt concentration were enhanced by submucosa negative voltage clamp and suppressed by positive voltage clamp. The complete CT response profile, including the time course of adaptation, was not uniquely determined by NaCl concentration alone. The response could be reproduced at different NaCl concentrations by applying a compensating voltage. 3. The form of the concentration and voltage dependence of the CT response indicates that the complete stimulus energy is the Na+ electrochemical potential difference across receptor cell apical membranes, and not Na+ concentration alone. This is the underlying principal behind the equivalence of chemical and electric taste for Na+ salts. 4. CT responses to sodium gluconate (25 and 200 mM) and 25 mM NaCl produced amiloride-insensitive components (AIC) of low magnitude. NaCl at 200 mM produced a significantly larger AIC. The AIC was voltage-clamp independent. The relative magnitude of the AIC was positively correlated with the transepithelial conductance of each salt. This suggests that the large AIC for 200 mM NaCl results from its relatively high permeability through the paracellular pathway. 5. Analysis of the CT response under voltage clamp revealed two anion effects on Na(+)-salt taste, both of which act through the paracellular shunt. 1) Anions modify the transepithelial potential (TP) across tight junctions and thereby modulate the cell receptor potential. This anion effect can be eliminated by voltage clamping the TP. 2) Sufficiently mobile anions facilitate electroneutral diffusion of Na+ salts through tight junctions. This effect is observed especially when Cl- is the anion and when the stimulus concentration favors NaCl influx, allowing Na+ to stimulate receptor cells from the submucosal side. Because the submucosal intercellular spaces are nearly isopotential regions, this effect is insensitive to voltage clamp of the TP. The large AIC associated with this anion effect is due to the low permeability of amiloride.

Afferent Pathways↗
PubMed1993

Dietary Na(+)-restriction prevents development of functional Na+ channels in taste cell apical membranes: proof by in vivo membrane voltage perturbation.

1. Chorda tympani (CT) neural responses to NaCl were recorded while the potential across the apical membrane of taste cells was perturbed by voltage clamp in rats fed a Na(+)-restricted diet pre- and postnatally (Na(+)-restricted rats) and in controls. 2. Control rats gave CT responses that were enhanced at negative voltage clamp and suppressed at positive voltage clamp. In contrast, CT responses from Na(+)-restricted rats were virtually voltage insensitive. 3. Analysis of the voltage-sensitivity of the CT response shows that Na(+)-restricted rats have < 10% of the density of functional apical Na+ channels normally present in control rats demonstrating that early dietary Na(+)-restriction prevents the functional expression of these key elements in salt taste transduction. Furthermore, the data demonstrate the value of this technique in assessing involvement of distinct cellular domains in taste transduction.

Animals↗
PubMed1993

Production of interferon alpha A by Escherichia coli W3110 (pEC901).

The maximum specific growth rate, saturation constant, maintenance coefficient and growth yield for E. coli W3110 (pEC901) and the host, W3110, were estimated through continuous cultivation of the two strains. The growth rate of the transformant was lower than that of the host, while its maintenance metabolism increased due to the existence of plasmids pEC901. Both the plasmid stability and the expression level of interferon increased with the increase in dilution rate. In fed-batch culture, the growth rate of W3110 (pEC901) was maintained at a high level by controlling the feeding rate of glucose, and the interferon titer reached 2.5 x 10(10) u/l, which was greatly improved compared with those reached in shaker flask cultures.

Escherichia coli↗
PubMed1993

Application of Steffee operation in spinal surgery.

Steffee operation is a surgical method of internal fixation for unstable conditions of the spine. Up to March 1991, 32 cases of various spine disorders were treated with the Steffee system in our hospital. These operations brought good results, as 83.4% of the cases received either good or excellent functional and clinical ratings postoperatively. Among patients with spondylolisthesis, the degree of slip correction averaged 58.5% postoperatively. Neurological complications are avoided by accurate localization of the screws.

Adult↗
PubMed1993

[The application of Dick instrumentation in the field of spine surgery].

From June, 1989 to March, 1991, 24 cases were treated in our department with the Dick technique. The study population included 7 patients with fresh horacolumber spine fracture, 10 with late spinal fracture (15 of the above 17 cases had incomplete paraplegia), 3 with ankylosing spondylitis, 2 with tuberculosis, and one each with spondylolisthesis and spine tumor. The results of these 24 cases were as follows. In the fresh fracture group, all the spine fractures were reduced completely. The 2 patients without neurological defects returned to work 3 months after operation. The 3 with incomplete paraplegia had rapid neurological recovery and could walk with a brace 3 months after surgical treatment. The 2 with complete paraplegia did not recover after toperation. In the late fracture group, traumatic kyphotic curve were reduced partially and back pain was decreased markedly in all 10 cases. Muscular power was increased significantly in 3 cases; they are all able to walk with a cane. Spasticity was remarkably improved in 2 patients after operation; they can now walk with crutches. Three patients obtained complete cure of incontinence. Four patients had no significant improvement. In the 3 patients with ankylosing spondylitis, the initial average kyphotic curve was 73.3 degrees, while the postoperative average curve was 28.3 degrees. The result in treating spinal stenosis due to degenerative spondylolisthesis was good: the slipping vertebrae were stabilized and fused with the Dick system after thorough decompression. In the tumor and Tb-spine cases, the patients recovered and were ambulatory soon after operation, thanks to rigid internal fixation.

Adult↗