Biomedical subjects

Y Song

Publications and source records attributed to Y Song.

At least 217 records · Page 12Linked to original sources

PubMed1999

Induction of macrophage C-C chemokine expression by titanium alloy and bone cement particles.

Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1alpha), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1alpha expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1alpha in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1alpha were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1alpha inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.

Antibodies, Monoclonal↗

PubMed1999

Effects of TGFbeta on bone ingrowth in the presence of polyethylene particles.

We implanted bone harvest chambers (BHCs) bilaterally in ten mature male New Zealand white rabbits. Polyethylene particles (0.3+/-0.1 microm in diameter, 6.4 x 10(12) particles/ml) were implanted for two, four or six weeks bilaterally in the BHCs, with subsequent removal of the ingrown tissue after each treatment. In addition to the particles, one side also received 1.5 microg of recombinant transforming growth factor beta1 (TGFbeta1). At two weeks, the bone area as a percentage of total area was less in chambers containing TGFbeta compared with those with particles alone (7.8+/-1.3% v 16.9+/-2.7% respectively; 95% confidence interval (CI) for difference -14.0 to -4.30; p = 0.002). At four weeks, the percentage area of bone was greater in chambers containing TGFbeta compared with those with particles alone (31.2+/-3.4% v 22.5+/-2.0% respectively; 95% CI for difference 1.0 to 16.4; p = 0.03). There were no statistical differences at six weeks, despite a higher mean value with TGFbeta treatment (38.2+/-3.9% v 28.8 +/-3.5%; 95% CI for difference -4.6 to 23.3; p = 0.16). The number of vitronectin-receptor-positive cells (osteoclast-like cells) was greater in the treatment group with TGFbeta compared with that with particles alone; most of these positive cells were located in the interstitium, rather than adjacent to bone. TGFbeta1 is a pleotropic growth factor which can modulate cellular events in the musculoskeletal system in a time- and concentration-dependent manner. Our data suggest that there is an early window at between two and six weeks, in which TGFbeta may favourably affect bone ingrowth in the BHC model. Exogenous growth factors such as TGFbeta may be a useful adjunct in obtaining osseointegration and bone ingrowth, especially in revisions when there is compromised bone stock and residual particulate debris.

Animals↗

PubMed1999

Drug pharmacophores covalently linked to the red cell surface are active without prior release. Drug targeting of renin with a synthetic ligand conjugated to red blood cells.

Red blood cells have been labeled with an anti-renin pharmacophore using the activated labeling agent Boc-Phe-His-ACHPA-Ile-6-NH(CH2)5CO-NHS (4) and the corresponding sulfo-NHS-ester (5). Renin inhibition by labeled cells varies according to the concentrations of 4 or 5 used in the labeling protocols, and with the densities of the red cells employed. Flow cytometry measurements using specific polyclonal antibodies toward the anti-renin pharmacophore confirm that red cells are labeled on their outer surfaces with anti-renin pharmacophores. Inhibitory activity of labeled red cells is clearly associated with the cells themselves, and does not require prior release of an inhibitory entity: renin inhibition increases as a function of the concentration of NHS-ester used to label cells suspended in buffer, and with cell density; on the other hand, the separated supernatant portions of the medium make only minor contributions to the observed inhibitory activities. Renin inhibition also increases with increasing concentrations of ghosts derived from labeled red cells, firmly establishing that activity is intimately associated with cell membranes. Thus, the composite evidence is strongly supportive of inhibitory activity specific to the extracellular surface of red cells, which has been modified by the introduction of anti-renin pharmacophores. This study of inhibitory activity by drug/red blood cell-conjugates represents one of the few examples of a red cell-bound ligand of synthetic origin capable, without prior release, of specifically blocking the activity of its target enzyme. As well, it demonstrates the feasibility of exploiting the activity of covalently bound pharmacophores, free from interference of their carriers, for drug targeting.

Antibodies↗

PubMed1999

Mechanisms of inactivation of p14ARF, p15INK4b, and p16INK4a genes in human esophageal squamous cell carcinoma.

The 9p21 gene cluster, harboring growth suppressive genes p14ARF, p15INK4b, and p16INK4a, is one of the major aberration hotspots in human cancers. It was shown that p14ARF and p16INK4a play active roles in the p53 and Rb tumor suppressive pathways, respectively, and p15INK4b is a mediator of the extracellular growth inhibition signals. To elucidate specific targets and aberrations affecting this subchromosomal region, we constructed a detailed alteration map of the 9p21 gene cluster by analyzing homozygous deletion, hypermethylation, and mutation of the p14ARF, p15INK4b, and p16INK4a genes individually in 40 esophageal squamous cell carcinomas (ESCCs) and compared the genetic alterations with mRNA expression in 18 of these samples. We detected aberrant promoter methylation of the p16INK4a gene in 16 (40%), of p14ARF in 6 (15%), and of p15INK4b in 5 (12.5%) tumor samples. Most p16INK4a methylations were exclusive, whereas all but one of the p14ARF/p15INK4b methylations were accompanied by concomitant p16INK4a methylation. We detected homozygous deletion of p16INK4a in 7 (17.5%), of p14ARF-E1beta in 13 (33%), and of p15INK4b in 16 (40%) tumor samples. Most deletions occurred exclusively on the E1beta-p15INK4b loci. Two samples contained p14ARF deletion but with p16INK4a and p15INK4b intact. No mutation was detected in the p14ARF and p16INK4a genes. Comparative RT-PCR showed good concordance between suppressed mRNA expression and genetic alteration for p15INK4b and p16INK4a genes in the 18 frozen samples, whereas 5 of the 13 cases with suppressed p14ARF mRNA expression contained no detectable E1beta alteration but aberrations in the p16INK4a locus. Our results show that in human ESCCs, p14ARF is a primary target of homozygous deletion along with p15INK4b, whereas p16INK4a is the hotspot of hypermethylation of the 9p21 gene cluster. The frequent inactivation of the p14ARF and p16INK4a genes may be an important mechanism for the dysfunction of both the Rb and p53 growth regulation pathways during ESCC development.

Carcinoma, Squamous Cell↗

PubMed1999

Osseointegration of total hip arthroplasties: studies in humans and animals.

Total hip replacement is a successful, time-proven surgical procedure for reconstruction of the arthritic hip joint. The state of the bone-implant interface is crucial to the long-term integration and durability of hip replacements whether cemented or cementless. This review summarizes current clinical implant retrieval and animal research in hip-joint reconstruction. Future research must attempt to extend the longevity of hip replacements to avoid complex revision surgery.

Animals↗

PubMed1999

[The influences of genetic and environmental factors on plasma plasminogen activator inhibitor-1 levels in patients with essential hypertension].

OBJECTIVE: To investigate the influence of a 4G/5G polymorphism in the PAI-1 gene promoter and environmental factors on plasma plasminogen activator inhibitor-1(PAI-1) levels in subjects with essential hypertension. METHODS: A total of 240 patients with essential hypertension(males 120, females 120, aged 33-89 years, mean 65 years) were randomly enrolled in this study. Plasma PAI-1 antigen was measured by ELISA. The 4G/5G polymorphism was analyzed by the allele specific oligonucleotide hybridization method. RESULTS: Plasma PAI-1 levels were significantly associated with 4G/5G polymorphism with the highest levels occurring in subjects with 4G/4G genotype, the intermediate levels in 4G/5G subjects and the lowest levels in 5G/5G subjects. 4G/5G polymorphism, diabetes mellitus and triglyceride(TG) were three independent predictors of plasma PAI-1 levels in a stepwise multiple regression model. Furthermore, the relationship between plasma PAI-1 levels and TG was genotype dependent. CONCLUSION: Plasma PAI-1 levels are not only under genetic control, but also influenced by several environmental factors. There is an interaction between genetic and environmental factors.

Adult↗

PubMed1999

[Anatomical basis for the newly developed facelifting].

OBJECTIVE: To investigate the relationship between the SMAS and the facial nerve divisions in the cheek area. METHOD: We dissected 12 cadaver heads(24 sides). RESULTS: 1. SMAS distributed over the middle face. It became thinner as it extended forward and there was a small aperture lateral to the mouth. The branches of facial nerve lay directly beneath the parotidomassetric fascia after emerging from the parotid gland. 2. The frontal branch penetrated the deep fascia to the SMAS at about 0.5 cm below the zygomatic arch. 3. Some buccal branches went through the cheek fat pad while the others lay on its surface directly under the thin SMAS. 4. There was constantly a zygomatic ramus went into the upper one third of the zygomaticus. It innervated the lower and lateral orbicularis oculi muscle in 9 of 24 sides (37.5%) of the cadaver heads, zygomaticus major and minor and orbicularis oculi muscle in 8 of 24 sides (33.3%), and the zygomaticus major and minor in 7 of 24 sides (29.2%). CONCLUSION: During facelifting, wide dissection of the SMAS should be done directly above the parotidomassetric fascia and 0.5 cm below the zygomatic arch. While approaching the middle face, the dissection should be limited to the lower two third of the zygomaticus, followed by elevating the zygomatic fat. The authors dissect the nasolabial fold through the lower eyelid incision, then the dissection should go downwards, under the orbicularis oculi muscle, to the nasolabial area. In a clinical situation, care must be taken not to damage the facial nerve trunk, and dissection of the upper one third of the zygomaticus should be avoided.

Adult↗

PubMed1999

[The distribution of the frontal branch of the facial nerve and its significance in facelift].

OBJECTIVE: To further understand the distribution and course of the frontal branch of the facial nerve in the temporal and zygomatic areas. METHODS: Facial dissection was performed on 9 cadaver heads(18 sides). RESULTS: It was found that the frontal of the facial nerve had 3 to 7 divisions (average 5) instead of one. The divisions of the frontal branch showed no constant course and distributed nearly all over the zygomatic arch. We divided the zygomatic arch into 3 equal parts and found that the middle third had the highest density of the branch distribution, accounting for 44.44% of the total divisions; the anterior third and the lateral third possessed 38.89% and 16.66% of the total divisions respectively. These divisions entered deeply into the temporoparietal fascia(the superficial temporal fascia). The divisions in the anterior third of the zygomatic arch innervate the lower and lateral orbicularis oculi muscle; the divisions in the middle third innervate the lateral orbicularis oculi muscle and the frontal muscle; the divisions in the lateral third innervate the frontal muscle and the anterior auricularis. CONCLUSION: We recommend discriminating the layers of the soft tissue over the zygomatic arch, not limiting the dissection range of the zygomatic arch to avoid damaging the nerve divisions while doing subperiosteal dissection of the zygomatic arch in facelifting.

Adult↗

PubMed1999

[Tissue response in circum-maxillary sutures after transverse palated suture expansion].

OBJECTIVE: This study was carried out to investigate the histological reactions of midfacial sutures induced by transverse palatal suture expansion. METHODS: Nine mongrel dogs of 8-week old were used in the study. Six of them were used as experimental group as described in a previous paper. The additional three served as controls. In the experimental dogs, a NiTi-shape memory alloy (NiTi-SMA) arch wire was used to expand the transverse palatal suture. Tetracycline was injected intramuscularly (50 mg/kg) three days before operation and at the time of sacrifice. Tissue reactions of premaxillo-maxillary suture, transverse palatal suture, zygomatico-maxillary suture, zygomatico-temporal suture and fronto-maxillary suture were observed in undecalcified tetracycline labeled sections and decalcified histological sections. RESULTS: The sutures in normal young dogs showed active bone formation. With the increase of age, the cellular components of the suture decreased. A great amount of new bone apposition was found in the bony front of expanded transverse palatal suture of the experimental dogs. Degenerative changes were found in premaxillo-maxillary suture at the expanded side while the contralateral showed active osteogenesis. Other sutures manifested both bone apposition and deposition due to the irregular interdigitations. CONCLUSION: After expansion, a great amount of new bone formed in the transverse palatal suture and thus the hard palate was lengthened. All the circum-maxillary sutures reacted in different patterns.

Animals↗

PubMed1999

[A study on guided tissue regeneration and tissue engineering-transplantation of collagen membrane seeded with cultured hyaline chondrocytes].

OBJECTIVE: Lack of transplant material is a main problem in the repair and reconstruction of tissue or organ defects. To seek the succedaneum of transplants, we studied and used tissue-engineered growth hyaline cartilage. METHODS: The articular hyaline cartilage obtained from newborn calf within 6 hours of sacrifice was enzymatically dissolved. The chondrocytes were then seeded onto the medical collagen membrane of guided tissue regeneration in a 24 well plate in RPMI1640 medium. One week later, the chondrocyte medical collagen membrane of guided tissue regeneration complex was implanted subcutaneously into the back of nude mice. Eight weeks after implantation, the animals were sacrificed. RESULTS: The present study seems to demonstrate that the cartilage-like tissue was strong enough to be transferred after being implanted for 8 weeks. The cartilage-like tissue was proved to be tissue-engineered hyaline cartilage by HE stain. The chondrocytes could secrete chondroitin sulfate as proved by Lev-Spicer stain. CONCLUSION: Tissue engineering technique was used to make tissue-engineered cartilage in vitro. It will provide a new transplant material for the repair of tissue or organ defects.

Animals↗

PubMed1999

[Suture expansion osteogenesis for closing the posterior hard palate: an experimental study in dogs].

OBJECTIVE: This study investigated the possibility of a new approach, e.g. suture expansion osteogenesis for closing the posterior hard palate. By this technique we might hope to replace missing tissue in the clefts by tissue regeneration and achieve bony repair in the posterior hard palate and circumvent the problems of speech and facial growth seen in traditional cleft surgery. METHODS: Nine 8-month mongrel dogs were divided into three groups: the control(n = 1), sham control(n = 2) and the experimental group(n = 6). In six experimental dogs, an 8 mm wide cleft was made surgically. Suture expansion devices made of NiTi-shape memory alloy with force levels of 200 g, 360 g and 480 g were secured in the palatine bones to expand the lateral sutures of the palatine bones. Clinical and histological examinations were performed to observe the changes. RESULTS: The clefts in the experimental group were closed completely sooner or later within a period from 5 to 14 days. While the clefts in the sham group became a little larger than their original size. There was significant new bone formation at the edge of the expanded suture. CONCLUSION: The clefts in young dogs could be closed by the technique of suture expansion. The NiTi-SMA expander used in the study was consistently effective and all the force levels could induce a great amount of new bone formation with the trabeculae being thinner and longer by heavy forces.

Animals↗

PubMed1999

Association of polymorphism of apolipoprotein E gene with coronary heart disease in Han Chinese.

OBJECTIVE: To investigate the association between apolipoprotein E (apoE) gene polymorphism and coronary heart disease(CHD) in Han Chinese. METHODS: Apo E genotype was examined with the methods of hot start polymerase chain reaction (PCR) and restriction isotyping in samples of 113 unrelated Chinese healthy individuals and 93 patients with CHD. The relation of the gene polymorphism of apoE and levels of serum lipids, lipoproteins, and apolipoproteins was also studied. RESULTS: The results showed that the epsilon 4/3 genotype was more frequent in CHD cases than in control subjects (31.2% vs. 11.5%, P < 0.01). The frequency of the epsilon 4 allele in CHD cases was significantly higher than in control subjects (17.2% vs 7.5%, P < 0.01). The epsilon 4 allele was associated with high concentrations of serum TC (r = 0.265, P < 0.05), LDL-C (r = 0.266, P < 0.05), and apoB (r = 0.360, P < 0.01). CONCLUSIONS: Hot start PCR assay is considered a rapid and simple technique for apoE genotyping. This method is suitable for routine laboratories and large scale population studies. Genetic polymorphism of the apoE gene might contribute to the determination of serum lipid profile and the development of CHD among Han Chinese.

Alleles↗

PubMed1999

[Hard palate lengthening by palatal suture expansion: an experimental study in dogs].

OBJECTIVE: Scar contraction and lack of bony support for soft palate in traditional surgery of cleft palate are main causes of a shortening soft palate and its developmental deficiency. The wound and scar also lead to aberration of facial growth. In order to resolve these problems, lengthening of hard palate by transverse palatal suture expansion was studied. METHODS: Six mongrel dogs of 8-week age were used in the study. Amalgam markers were implanted in the hard palate of the animal. A NiTi-shaped memory alloy (NiTi-SMA) arch wire with a force level of 600 g was used to expand the palato-maxillary suture with a retention period of 8 weeks. The dogs were killed at the age of 36 weeks. Serial X-ray and cephalometry were used to investigate the changes. RESULTS: The suture expansion was generally completed in 4 weeks. The distance of separation of the palatine bone and maxilla was 1.0 to 1.5 cm. Premaxilla became protrusive significantly at the beginning of the suture expansion, then restored gradually to its original position. The length of hard palate increased 4.6 to 5.9 mm by dry skull measurement. CONCLUSION: Hard palate could be permanently lengthened anterior-posteriorly by transverse palatal suture expansion.

Animals↗

PubMed1999

[Transfection of Fas(CD95) gene into HL-60 cell and its role in rhG-CSF-induced apoptosis].

OBJECTIVE: To explore the role of Fas gene in rhG-CSF-induced apoptosis. METHODS: Mediated by lipofection (DOTAP), Fas cDNA was transferred into HL-60 cells. In situ hybridization, Western blotting and FCM analysis were used to demonstrate the successful transfection. The apoptosis percentages of HL-60 and Fas transfected HL-60 cells were compared after coculturing with rhG-CSF at the same final concentration. RESULTS: After cocultured with rhG-CSF (10 ng/ml) for 96 hours, the apoptosis percentage of Fas transferred HL-60 cells was significantly higher than that of HL-60 cells, and the Fas expressions could be up-regulated by rhG-CSF. CONCLUSIONS: Fas is an apoptosis-induction oncogene, and rhG-CSF induces apoptosis of HL-60 cells through Fas signalling pathway.

Apoptosis↗

PubMed1999

[Expressions of cellular M-CSF and M-CSFR in hematopoietic cells].

OBJECTIVE: To study the distribution of cellular M-CSF and its receptor in abnormal hematopoiesis. METHODS: Six hematopoietic cell lines, 144 bone marrow (BM) and 160 peripheral blood (PB) samples were investigated with ABC immunoperoxidase assay. RESULTS: Cellular M-CSF and/or M-CSFR were positive in all the 6 hematopoietic cell lines, a few normal BM(4 cases) and PB (32 cases) samples, hematological malignancies and a few benign hematological disorder samples. M-CSF and M-CSFR were found mainly in granulocytic lineage cells, seldom in erythroid and megakaryocytic lineage cells and never in lymphocytes. M-CSF and M-CSFR usually presented in cytoplasma and membrane and in some cases in nuclei. CONCLUSION: Cellular M-CSF and M-CSFR is widely distributed in abnormal hematopoiesis, and is especially high in myeloid leukemias.

HL-60 Cells↗

PubMed1999

[Successful treatment of AML by HLA-compatible sibling umbilical cord blood stem cell transplantation--the first case report in China].

OBJECTIVE: To apply umbilical cord blood stem cell transplantation (UCBSCT) to the treatment of hematological malignancies, and to observe the persistent hematopoietic reconstitution, graft-versus-host disease (GVHD) and transplantation-related complications. METHODS: An 11-year-old patient with acute myeloid leukemia in complete remission (CR) received UCBSCT from a HLA-compatible sibling. The conditioning regimen was BU/CY (busulfan 4 mg.kg-1.d-1 x 4, cyclophosphamide 60 mg.kg-1.d-1 x 2). CsA was given for prophylaxis of acute GVHD. The patient received 0.35 x 10(8) nucleated cells/kg, including 1.82 x 10(4) CFU-GM/kg and 2.04 x 10(5) CD34+ cells/kg. RESULTS: The recipient showed hematopoietic reconstitution on day 14 post-transplantation; ANC > 1.0 x 10(9)/L on day 21; DNA fingerprinting showed engraftment on day 60, the blood type of the patient changed from O group to B group. In the follow-up of 330 days, the patient was in good condition without acute or chronic GVHD. CONCLUSION: It is the first case reported in China that have succeeded in the treatment of acute myeloid leukemia by allogeneic UCBSCT.

Blood Grouping and Crossmatching↗

PubMed1999

Clinical analysis of 1539 cases undergoing coronary artery bypass grafting.

OBJECTIVE: To analyze clinical factors affecting the outcome of coronary artery bypass grafting (CABG). METHODS: 1539 patients were divided into the following two groups based on admission sequence: group I (n = 570), 1974-1994; group II (n = 969), 1995-1998. Comparison of clinical data and procedure between the two groups was made. RESULTS: After CABG, 1482 patients were alleviated from angina, 57 patients died within 30 days of operation, with an overall mortality rate of 3.7%. The mortality rates in group I and group II were 7.9% and 1.2%, respectively. Since 1995, the mortality rate has significantly decreased. CONCLUSION: CABG is a safe and effective therapy for coronary heart disease. Surgical technique is a key factor affecting the outcome of CABG in selected patients.

Adult↗

PubMed1999

[The role of apoptosis and Fas/FasL in lung tissue in patients with acute respiratory distress syndrome].

OBJECTIVE: To evaluate the effects of apoptosis and expression of apoptotic related genes on acute respiratory distress syndrome (ARDS). METHODS: Nine patients with ARDS and 5 non-ARDS patients were included. By using TUNEL, histopathology and immunocytochemistry techniques, apoptosis and Fas, FasL protein expression were studied in patients with ARDS in acute stage and in control subjects. RESULTS: Apoptosis ratio was significantly higher in lung tissues in the patients with ARDS than in those of control subjects, especially in alveolar epithelial cells and pulmonary vascular endothelial cells. Fas, FasL protein expression were up-regulated in lung tissues of patients with ARDS. There was a significant correlation between expression of Fas, FasL and ratio of apoptosis. CONCLUSIONS: During the acute stage of ARDS, increase of apoptosis ratio in alveolar epithelial cells and pulmonary vascular endothelial cells, and activation of Fas/FasL system may contribute to the pathogenesis of this syndrome.

Adult↗