Biomedical subjects

Yu Zhao

Publications and source records attributed to Yu Zhao.

At least 127 records · Page 7Linked to original sources

PubMed2004

[Biocompatibility of p(3HB-co-3HH) and marrow mesenchymal stem cells].

OBJECTIVE: To investigate the biocompatibility of p(3HB-co-3HH) and marrow mesenchymal stell cells (MSCs). METHODS: MSCs were inoculated to p(3HB-co-3HH), and then cultured for 2-4 weeks in vitro and embedded for 2 weeks in vivo. The growth, proliferation, morphology and phenotype properties of MSCs were observed by use of phase contrast microscope, electron microscope, HE staining and staining of type I collagen. RESULTS: p(3HB-co-3HH) had good compatibility. The inoculated MSCs could be well-distributed, attached well and obtain the phenotype of MSCs in p(3HB-co-3HH). After osteogenic inducer were added, MSCs differentiated to osteoblasts and secreted matrix. Type I collagen was stained positively by immunohistochemical techenique. CONCLUSION: The above results demonstrate that there is satisfactory biocompatibility between p(3HB-co-3HH) and MSCs.

3-Hydroxybutyric Acid↗

PubMed2004

[Re-growth of induced-osseous tissue encapsulated in muscular fasciae for prefabrication of an osteo-musculo-cutaneous flap].

OBJECTIVE: To improve the survival of mesenchymal stem cells (MSCs) for prefabrication of an osteo-musculo-cutaneous flap. METHODS: In a mouse model, the compound of MSCs and p(3HB-co-3HH) were embeded in the latissimus dorsi muscle as an experimental group and the muscle pocket of the buttock as the control. The examinations of the HE staining, hybridization in situ of osteonectin mRNA and Von kossa staining were used to evaluate the results. RESULTS: The expression of osteonectin mRNA and the Von kossa staining showed that the latissimus dorsi muscle group was superior to the control in 2 weeks and 4 weeks after the surgery in vivo. CONCLUSION: The results indicate that the above-mentioned technique may be a good alternative for the prefabrication of the osteo-musculo-cutaneous flap.

Animals↗

PubMed2004

[Expression of neuronal nitric oxide synthase and inducible nitric oxide synthase in the erector spinal muscles in idiopathic scoliosis].

OBJECTIVE: To explore the possible mechanism of the erector spinal muscles in idiopathic scoliosis by comparing the expression and localization of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) of the thoracic erector spinal muscles on convex side and concave side. METHODS: The patient group comprised 8 females and 2 males who were scheduled for spinal surgery. The apex of scoliotic curve in these patients arose between T6 and T11. The mean age was 14.3 (range 12-17) years, and the mean Cobb angle was 57.7 degrees (range 45 degrees-85 degrees). Muscle biopsies were taken bilaterally during surgery from the superficial multifidus muscle at the apex of the curve between the 6th and 11th thoracic vertebral levels. Part of the tissue was fixed in formalin and stained with hematoxylin and eosin; the remaining tissue was snap frozen and processed for immunohistochemistry and Western blot. Immunocytochemistry for nNOS and iNOS were performed using the EnVision two-step method. Western blot was done with antibodys to nNOS and iNOS. Immunoreactive bands were visualized by enhanced chemiluminescence according to the manufacturer's specifications (Amersham Corp). RESULTS: nNOS protein in the erector spinal muscles was localized at the sarcolemma. Western blot demonstrated that nNOS protein expression in the concave side of erector spinal muscles is more than that in the convex side. A significant decrease in nNOS protein and activity was found on the convex side of erector spinal muscles from idiopathic scoliosis patients; There was a little immunoreactivity to iNOS in erector spinal muscles. There was little difference in iNOS protein expression between both sides of the curve. Western blot detected the same results. CONCLUSION: There is a greater expression of nNOS and iNOS on the concave side than on the convex side, suggesting nNOS and iNOS may play a role in the pathogenesis of idiopathic scoliosis.

Adolescent↗

PubMed2004

[Clinical and histological evaluation of the injectable hydrophilic polyacrylamide gel].

OBJECTIVE: To investigate the clinical and histological features of the complications after hydrophilic polyacrylamide gel injection. METHODS: Fifty-two patients were included in this study, who had undergone hydrophilic polyacrylamide gel injection in other units from 1998 to 2003 and later came to our department for removal of the injected gel. The tissue samples taken from each cyst were sectioned and stained with hematoxylin and eosin. The sections were investigated and analyzed under light microcopy. The tissue sections of 12 patients who had ever received liquid silicone injection from 1988 to 1994 were used as the control group. The difference in histological features was assessed. RESULTS: The inflammatory reaction of the hydrophilic polyacrylamide gel was characterized by an increased number of foreign-body giant cells. The mild lymphocyte infiltration was shown in the slides of hydrophilic polyacrylamide gel. On the contrary, there were much more clusters or lymphocyte infiltration in the slides of liquid silicone. The differences between the hydrophilic polyacrylamide gel and liquid silicone were significant in terms of thickness of the fibrous capsule. CONCLUSIONS: The security of hydrophilic polyacrylamide gel injection for soft tissue augmentation is in doubt.

Acrylic Resins↗

PubMed2004

[Comparison of endoscopic versus open surgical treatment of carpal tunnel syndrome].

OBJECTIVE: To compare the results of endoscopic surgical decompression of carpal tunnel release (CTR) with open CTR in patients with idiopathic carpal tunnel syndrome (CTS). METHODS: Forty patients with CTS were randomly chosen for a prospective study from April 2000 to August 2002. Endoscopic CTR was performed in 23 CTS patients (26 sides) and open CTR was performed in 17 CTS patients (21 sides). Five parameters were evaluated, including each patient's symptom amelioration, complication, operation time, hospitalization time, and the time needed to resume normal lifestyle. The mean follow-up time was 2 years. RESULTS: No significant difference was observed between the endoscopic CTR group and open CTR group in regard to symptom amelioration, electromyographic testing, and complications. In comparison to open CTR, endoscopic CTR significantly decreased operation time, hospitalization time, and the time needed to resume normal lifestyle and activity (P < 0.01). CONCLUSION: Compared with open CTR, endoscopic CTR has the advantage of reduced pain of scar and shortened time of hospitalization and recovery. It is a safe and effective method for treating idiopathic CTS.

Adult↗

PubMed2004

[Establishment of plantlet regeneration system of medicinal plant Aconitum coreanum].

OBJECTIVE: To set up the rapid propagation and plantlet regeneration system of medicinal plant Aconitum coreanum (Levi.) Rpaics. METHOD: Adventitious buds and regenerated plantlet were obtained by shoot tip culture through different media and combination of plant growth regulators. RESULT: MS medium was the optimal medium for differentiation and proliferation of shoot tip. MS medium with 6-BA 2 to approximately 5 mg/L was found to be most suitable for the induction of bud. MS with 6-BA 2 mg/L + GA3 1 to approximately 5 mg/L or adenine 1 to approximately 5 mg/L was best combination for the growth and proliferation of adventitious buds, and MS with IBA 0.5 to approximately 1 mg/L for the induction of root. CONCLUSION: Tip culture may be used as a useful method to get regenerated plantlet of Aconitum coreanum under certain conditions.

Aconitum↗

PubMed2003

Antidepressant-induced increase in high-affinity rolipram binding sites in rat brain: dependence on noradrenergic and serotonergic function.

The effects of antidepressant treatment on the high- and low-affinity rolipram binding sites on type 4 phosphodiesterase (PDE4) were determined; previous work had shown that repeated antidepressant treatment increases the overall expression of PDE4. Rats were administered different doses of the antidepressant drugs desipramine or fluoxetine, or saline, for 1, 7, or 14 days. [3H]Rolipram and [3H]piclamilast were used to assess the high-affinity rolipram binding sites (HARBS) and low-affinity rolipram binding sites (LARBS) on PDE4 in the hippocampus and cerebral cortex. Repeated, but not acute, treatment with the antidepressants increased [3H]rolipram binding to membrane fractions in a dose-dependent manner; the HARBS component of [3H]piclamilast binding also was increased by these treatments. By contrast, the LARBS component of [3H]piclamilast binding was not altered. [3H]Rolipram and [3H]piclamilast binding to the cytosolic fractions of rat cerebral cortex and hippocampus was not altered by the antidepressant treatments. 6-Hydroxydopamine (6-OHDA; 300 microg i.c.v.) and 5,7-dihydroxytryptamine (5,7-DHT; 200 microg i.c.v.) were used to lesion noradrenergic and serotonergic neurons, respectively. The effects of desipramine, but not fluoxetine, on [3H]rolipram and [3H]piclamilast binding to rat hippocampal membranes were blocked by the 6-OHDA-induced lesion. By contrast, the effects of fluoxetine, but not desipramine, were reduced by the 5,7-DHT-induced lesion. This indicates that the up-regulation of the HARBS by desipramine and fluoxetine requires the integrity of noradrenergic and serotonergic neurons, respectively. Collectively, these results suggest that antidepressants, although acting through different pathways, may eventually lead to the regulation of components of the cAMP signal transduction system.

Animals↗

PubMed2003

Extracellular signal-regulated kinases and contractile responses in ovine adult and fetal cerebral arteries.

Accumulating evidence suggests that extracellular signal-regulated kinases (ERK1/2) play a key role in regulating vascular tone. To test the hypotheses that ERK1/2 modulate cerebral artery agonist-induced contraction, and that this changes with developmental age, we measured both total and phosphorylated ERK1/2 in adult and fetal ovine cerebral arteries. In middle cerebral arteries (MCA) we also examined tension and [Ca2+]i responses to phenylephrine (PHE), in the absence and presence of the ERK1/2 inhibitor U-0126 and the mitogen-activated protein kinase kinase (MAPKK or MEK) inhibitor PD-98059. In the fetus, but not adult, U-0126 potentiated PHE-induced contraction. In both age groups, inhibition by U-0126, but not PD-98059, decreased the PHE-induced [Ca2+]i increase; in fact for adult, this eliminated any significant [Ca2+]i increase. In turn in the adult, but not fetus, protein kinase C (PKC) inhibition by staurosporine (3 x 10(-8) M) prior to ERK1/2 inhibition by U-0126 (10(-5) M) prevented this elimination of [Ca2+]i increase. In adult and fetal cerebral arteries basal total ERK1/2 levels were similar. However, in fetal arteries the basal phosphorylated ERK1/2 levels were significantly less than in adult. In fetal, but not adult, cerebral arteries, 10(-6)-10(-4) M PHE increased ERK1/2 phosphorylation in a concentration- and time-dependent manner. The ERK1/2 inhibitor U-0126, but not the MEK inhibitor PD-98059, lowered basal activated ERK1/2 levels in vessels of both age groups. These results suggest that basal levels of phosphorylated ERK1/2 play an important role in suppressing Ca2+ sensitivity, perhaps by PKC inhibition. The developmental increase in cerebral artery basal phosphorylated ERK levels from fetus to adult, suggests a transition in the regulation of contraction from Ca2+ sensitivity in the fetal arteries to Ca2+ concentration in the adult vessels.

Adrenergic alpha-Agonists↗

PubMed2003

Solid-solid contacts due to surface roughness and their effects on suspension behaviour.

Solid-solid contacts due to microscopic surface roughness in viscous fluids were examined by observing the translational and rotational behaviours of a suspended sphere falling past a lighter sphere or down an inclined surface. In both cases, a roll-slip behaviour was observed, with the gravitational forces balanced by not only hydrodynamic forces but also normal and tangential solid-solid contact forces. Moreover, the nominal separation between the surfaces due to microscopic surface roughness elements is not constant but instead varies due to multiple roughness scales. By inverting the system, so that the heavy sphere fell away from the lighter sphere or the plane, it was found that the average nominal separation increases with increasing angle of inclination of the plane or the surface of the lighter sphere from horizontal; the larger asperities lift the sphere up from the opposing surface and then gravity at large angles of inclination is too weak to pull the sphere back down to the opposing surface before another large asperity is encountered. The existence of microscopic surface roughness and solid-solid contacts is shown to modify the rheological properties of suspensions. For example, the presence of compressive, but not tensile, contact forces removes the reversibility of sphere-sphere interactions and breaks the symmetry of the particle trajectories. As a result, suspensions of rough spheres exhibit normal stress differences that are absent for smooth spheres. For the conditions studied, surface roughness reduces the effective viscosity of a suspension by limiting the lubrication resistance during near-contact motion, and it also modifies the suspension microstructure and hydrodynamic diffusivity.

Computer Simulation↗

PubMed2003

Eudesmane and megastigmane glucosides from Laggera alata.

Four eudesmane glucosides, alatosides A-D (1-4), and one megastigmane glucoside, alatoside E (5), were isolated from the BuOH fraction of Laggera alata along with six known compounds. Structures of the new compounds were elucidated by a combination of chemical and spectroscopic methods. Alatosides A-E were characterized as: 1alpha-O-(beta-D-glucopyranosyloxyl)-7-epi-eudesma-11-en-2beta,4alpha-diol (1), 2beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4alpha-hydroxyl-11(13)-en-12-oic-acid (2), 5beta-O-(beta-D-glucopyranosyloxyl)-eudesma-4(15),11(13)-dien-12-oic-acid (3), 5alpha-O-(beta-D-glucopyranosyloxyl)-eudesma-3,11(13)-dien-12-oic acid (4) and 3beta-O-(beta-D-glucopyranosyloxyl)-megastigma-9-one (5), respectively. Based on the chemical characteristics of eudesmane derivatives isolated from the Laggera genus, it was suggested that there are probably two different biogenetic pathways for these secondary metabolites in this genus.

Asteraceae↗

PubMed2003

Eudesmane derivatives from Laggera pterodonta.

A new eudesmane derivative, 4alpha,5alpha-dihydroxyeudesma-11(13)-en-12-oic acid, was isolated from Laggera pterodonta. Its structure was elucidated as (1) on the basis of spectroscopic evidence. Moreover, six known compounds were isolated: pterodontriol A (2), pterodontriol B, pterodonta acid (3), ilicic acid (4), costic acid and beta-amyrin. Cytotoxic activity of compounds 2, 3 and 4 was investigated.

Antineoplastic Agents↗

PubMed2003

Eudesmane derivatives and other sesquiterpenes from Laggera alata.

Three new eudesmane sesquiterpenes, 5 beta-hydroxyilicic acid (1), 5 alpha-hydroxyl-4-epi-ilicic acid methyl ester (2), and 3 alpha-hydroxyilicic acid (3), together with 12 known sesquiterpenes were isolated from the aerial part of Laggera alata. Their structures were elucidated primarily by NMR and mass spectroscopic methods. The structures of 1 and 2 were confirmed by X-ray crystallography.

Asteraceae↗

PubMed2003

Inhibitor binding to type 4 phosphodiesterase (PDE4) assessed using [3H]piclamilast and [3H]rolipram.

Piclamilast is a type 4 phosphodiesterase (PDE4) inhibitor with equal affinity for the high-affinity rolipram binding site (HARBS) and low-affinity rolipram binding site (LARBS). The binding of [(3)H]piclamilast to preparations of rat brain and peripheral tissue was investigated and compared with that of [(3)H]rolipram. [(3)H]piclamilast binding was high-affinity, saturable, reversible, and partially Mg(2+)-dependent. Binding was detected both to membrane and soluble fractions, with K(d) values of 3.1 and 4.5 nM, respectively. The B(max) values for [(3)H]piclamilast were about 1.5-fold greater than that of [(3)H]rolipram binding, suggesting that [(3)H]piclamilast, but not [(3)H]rolipram, binds to LARBS as well as the HARBS. The HARBS was present in all the brain regions examined, but not in peripheral tissues. All PDE4 inhibitors tested were potent competitors for [(3)H]piclamilast binding; the competition curves for rolipram, desmethylpiclamilast, ICI 63,197, and Ro 20-1724 were better described by a two-site model, while the competition curves for piclamilast, cilomilast, roflumilast, and CDP 840 were adequately described by a one-site model. Inhibitors of other PDE families were much less potent. The inhibition of [(3)H]piclamilast was further tested in the presence of 1 microM rolipram to isolate the LARBS. Under this condition, the competition curves for all the inhibitors were adequately described by a one-site model, with K(i) values close to that for the LARBS. The results indicated that [(3)H]piclamilast is a useful tool to directly study inhibitor interaction with the HARBS and the LARBS in rat brain.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed2003

Autoregulation in the biosynthesis of ribosomes.

The synthesis of ribosomes in Saccharomyces cerevisiae consumes a prodigious amount of the cell's resources and, consequently, is tightly regulated. The rate of ribosome synthesis responds not only to nutritional cues but also to signals dependent on other macromolecular pathways of the cell, e.g., a defect in the secretory pathway leads to severe repression of transcription of both rRNA and ribosomal protein genes. A search for mutants that interrupted this repression revealed, surprisingly, that inactivation of RPL1B, one of a pair of genes encoding the 60S ribosomal protein L1, almost completely blocked the repression of rRNA and ribosomal protein gene transcription that usually follows a defect in the secretory pathway. Further experiments showed that almost any mutation leading to a defect in 60S subunit synthesis had the same effect, whereas mutations affecting 40S subunit synthesis did not. Although one might suspect that this effect would be due to a decrease in the initiation of translation or to the presence of half-mers, i.e., polyribosomes awaiting a 60S subunit, our data show that this is not the case. Rather, a variety of experiments suggest that some aspect of the production of defective 60S particles or, more likely, their breakdown suppresses the signal generated by a defect in the secretory pathway that represses ribosome synthesis.

Blotting, Northern↗

PubMed2003

Studies of five microelement contents in human serum, hair, and fingernails correlated with aged hypertension and coronary heart disease.

Using atomic absorption spectrometry (AAS), five microelements in human serum, hair, and fingernails of aged hypertension, coronary heart disease (diseased group) and aged health control (healthy group) were detected. Results of the t-test are as follows: The iron, zinc, and cadmium contents and Zn/Cu (mol/mol) ratio of the diseased group were significantly higher than that of the healthy group in serum (p<0.01, p<0.05, p<0.01, and p<0.05, respectively); the chromium contents in the serum, hair, and fingernails (p<0.05, p<0.01, and p<0.05, respectively); the iron and zinc contents in the hair and fingernails (p<0.01, p<0.001, p<0.05, and p<0.01 respectively) and Zn/Cu ratio in the hair (p<0.01) of the diseased group were significantly lower than that of the healthy group.

Aged↗

PubMed2003

[Comparison of curative effect of autologous peripheral blood stem cell transplantation versus bone marrow transplantation for acute leukemia].

To compare the clinical outcome of autologous peripheral blood stem cell transplantation (APBSCT) and autologous bone marrow transplantation (ABMT) in treatment of patients with acute leukemia in first remission, 41 patients received APBSCT, 17 patients received unpurged ABMT and 30 patients received purged ABMT. The results showed that hematopoietic recovery was significantly earlier after APBSCT than that after purged or unpurged ABMT. The 3-year disease-free survival (DFS), relapse rate (RR) and transplant-related mortality (TRM) for all patients of 3 groups were 51.7%, 41.7% and 6.8%, respectively. DFS and RR were significantly influenced by disease types (ALL or AML) and intervals between diagnosis and CR(1) or CR(1) and transplant. The main causes of transplant-related death were infection and hemorrhage. After APBSCT, DFS, RR and TRM were 48.4%, 43.9% and 4.9%, respectively, and did not differ significantly from those found in unpurged ABMT (47.1%, 45.6% and 11.8%) or purged ABMT (66.5%, 29.6% and 6.7%). It is concluded that the clinical outcome of APBSCT is similar to unpurged or purged ABMT but APBSCT allows faster recovery of hematopoiesis and needs less transfusion support.

Acute Disease↗

PubMed2003

[Classification and treatment of asymmetrical breast deformity].

OBJECTIVE: To evaluate the classification and the treatment of the asymmetrical breast deformity. METHODS: From April of 1997 to October of 2001, 90 patients with the asymmetrical breast deformity were undergoing in the study. The patients were classified and the results of the treatment were evaluated with the pre-operative and post-operative photographs. RESULTS: The deformities of the asymmetrical breast could be divided into seven types according to the selected treatment techniques. The results were very satisfactory in 77 cases (87%), general satisfactory in 10 cases (11%) and unsatisfactory in 3 cases (2%). There were 54 cases (60%) with complete symmetry results, 32 cases (35.5%) with general symmetry and 4 cases (4.5%) with still asymmetry. CONCLUSION: The indications for treatment of the breast asymmetry deformities should be correlated with the classification so as to achieve more satisfactory results, in fact, it is still difficult to be a complete symmetry.

Breast↗

PubMed2003

[A pathologic analysis on 9,666 cases of tumors of nose, pharynx and throat].

OBJECTIVE: To analyze nasal, pharyngeal and laryngeal tumor patients age, sex and tumors' sites, to find out the relationship of above indices and tumor's pathologic types. METHODS: 9,666 cases of tumors on nose, pharynx and throat diagnosed in West-China Hospital in 1984 to 1999 were analyzed for the constitution of histological type. RESULTS: 1. the ratio of benign and malignant tumor is 1:8.6, it is 1:62.0 in nasalpharynx; 2. papilloma, angiofibroma and angioma are more commonly seen in all 21 kinds of benign tumors; 3. differentiated squamous cell carcinoma, non-keratinized is the most common types in 25 kinds of malignant tumors, the ratio of carcinoma and sarcoma is 11.98 to 1; 4. The average age of patients with malignancy is about 10 years older than that of the patients with benign tumors, and malignant patients are male predominant; 5. squamous cell papilloma of oralpharynx was the most common in all benign tumors; nasopharyngeal carcinoma is the most common in all malignancies, nasal lymphomas are the most common seen sarcoma. CONCLUSION: The histologic types of nasal, pharyngeal and laryngeal tumors are related with patients' age, sex and sites of tumors.

Adolescent↗