Biomedical subjects

Jian Sun

Publications and source records attributed to Jian Sun.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Relaxant effect of Astragalus membranaceus on smooth muscle cells of rat thoracic aorta].

OBJECTIVE: To investigate the effect of Astragalus membranaceus(AM) on vascular circles and the underlying mechanisms. METHODS: The study was performed with the model of isolate rat thoracic aorta rings in organ bath. When the endothelium of rat thoracic aorta was removed,the effect of accumulated AM on aorta rings in resting tension, or pre-constricted with KCl, or pre-constricted with phenylephrine (PE) was observed. And to explove the mechanism, the aorta rings were incubated with Ca(2+)-free medium alone, or Ca(2+)-free medium plus heparin, or propranolol alone before pre-contraction with PE. RESULTS: AM had no significant effects on aorta rings in resting tension or pre-constricted with KCl. When the concentration of AM was cumulated to 10(-1), 3 x 10(-1),10(0), 3 x 10(0) g/L, it caused concentration-dependent relaxation while aorta rings were pre-constricted with PE(3 x 10(-7)mol/L), compared with the control [(90.4 +/-4.2)% compared with (94.7 +/-2.4)%,(86.1 +/-5.0)% compared with (92.6 +/-3.2)%, (82.3 +/-5.9)% compared with (90.4 +/-3.6) %, (78.3 +/-6.0)% compared with (88.1 +/-4.0)%]. This effect was not inhibited by Ca(2+)-free medium or propranolol alone. However, the effect was attenuated by the co-incubation with heparin and Ca(2+)-free medium [without heparin:(76.2+/-4.3)% compared with (92.3 +/-5.9)%, with heparin: (95.3+/-0.5)% compared with (95.1+/-0.6)%]. CONCLUSION: The results indicate that AM can relax the rat thoracic aorta rings without endothelium. The mechanism may include the inhibition of intracellular calcium ions release by the 1,4,5-triphosphate inositol-receptor-dependent pathway in vascular smooth muscle cells.

Animals↗

PubMed2005

[Changes of endothelial progenitor cells from peripheral blood in patients with coronary heart diseases].

OBJECTIVE: To investigate alterations of endothelial progenitor cells (EPCs) from peripheral blood in patients with coronary heart diseases. METHODS: Twenty patients with coronary heart diseases (CHD) and 20 matched control subjects were included in the study. Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After cultured for 7 days, attached cells were cytochemically analyzed. EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin-binding by laser scanning confocal microscope with direct fluorescent staining. EPCs proliferation and migration were measured by MTT assay and modified Boyden chamber assay, respectively. EPCs adhesion assay was performed by replating on fibronectin-coated dishes, then adherent cells were counted. RESULTS: The number of EPCs was significantly reduced in patients with CHD compared with that of age-matched control subjects (31.8+/-7.7 compared with 59.5 +/-10.6 EPCs/x 200 field; P<0.05). In addition, the functional activity of EPCs such as proliferation, migration and adhesive capacity was also impaired in patients with CHD. CONCLUSION: EPCs number and functional activity are significantly decreased in patients with CHD.

Aged↗

PubMed2005

[Retention and rehabilitation of complex maxillofacial defects based on bar-clip and stud attachment].

PURPOSE: To evaluate the application of precise attachment in restoration of complicated maxillofacial defect. METHODS: A framework with bar-clip and stud attachment was designed and fabricated. Maxillofacial prosthesis with this framework was applied to treat a patient with defects of nose, entire upper lip and the corresponding maxillofacial areas. The retention force was tested with Universal Testing Device. RESULTS: After treatment, the patient got a better appearance, normal function of mastication and clear pronunciation. The dislodgement test showed the retention force was 40N. CONCLUSION: Application of precise attachment in complicated maxillofacial defects can get satisfactory result.

Humans↗

PubMed2005

[Evaluation of mastication function after three-dimensional maxillary reconstruction].

OBJECTIVE: To evaluate the mastication function of the patient whose maxilla was reconstructed with individual titanium mesh and Chinese flap or combined with fibular flap. The superiority of this method on maxillary functional reconstruction was testified. METHODS: Since March of 2001, 10 cases of maxillary defect were reconstructed with individual titanium mesh and Chinese flap or combined with fibular flap, and routine removal partial dentures were fixed after 3 - 6 months postoperatively. Assessment of occlusal force was proceeded by T-Scan II system (Tekscan company, USA). RESULTS: The occlusal force analysis results indicated the asymmetry index of bite force and asymmetry index of occlusal contact area differed significantly between preoperation and postopertion (P < 0.05). The recovery rate of total occlusal force was between 27.05%-74.06%, and the average was 50.15%. CONCLUSION: This new three-dimensional maxillary functional reconstruction method had a satisfactory recovery in both of contour and function recently, especially restored the mastication function effectively.

Humans↗

PubMed2005

[The diagnostic application of bedside measurement of plasma brain natriuretic in patients with heart failure].

OBJECTIVE: To investigate differential diagnoses value of ultra-rapid bedside measurement of brain natriuretic peptide (BNP) in patients with dyspnea. METHODS: Plasma BNP concentration were measured with immunofluorescence assay in 103 patients with dyspnea. Left ventricular ejection fraction (LVEF) and pulmonary capillary wedge pressure (PCWP) were determined by echocardiography and Swan-Ganz catheter in these patients on the same time, respectively. RESULTS: (1) Plasma BNP levels in the patients with heart failure were higher than those in the non-heart failure patients [(716 +/- 86 vs 46 +/- 7) ng/L, P < 0.01]. (2) The sensitivity, specificity and negative predictive values of Plasma BNP levels > or = 100 pg/ml for predicting heart failure were 95.2% (60/63), 93.0% (40/43) and 97.1% (100/103), respectively. (3) Plasma BNP levels were positively related to PCWP, and negatively related to LVEF (r = -0.56, both P < 0.01). CONCLUSION: Bedside BNP assay is sensitive and specific for diagnosing heart failure, and is useful in evaluating dyspnea in emergency care.

Aged↗

PubMed2005

[Reversing effect of brassinolide on multidrug resistance of-CCRF-VCR1000 cells and a preliminary investigation on its mechanisms].

AIM: To investigate the effect of brassinolide, a plant growth modulator, on multidrug resistance (MDR) of human T lymphoblastoid cell line CCRF-VCR 1000 which was obtained by progressively addition of vincristine (VCR) to sensitive CCRF-CEM cells, and to explore preliminarily the mechanism of reversing action. METHODS: MTT method was used to detect the resistant factor of resistant cell line and the reversing fold after addition of brassinolide. The intracellular accumulation of rhodamine 123, a fluorescent dye transported by P-glycoprotein was detected by flow cytometry, the catalytic activity of topoisomerase II was assessed by Sulliven method to find the effect of brassinolide on resistance. The protein expression of p53 was measured using Western blotting in the sensitive cells and resistant cells to explore the effect of brassinolide. RESULTS: The resistant factors of CCRF-VCR cells on adriamycin, VP-16 and VCR are respectively as 153.1, 55.9 and 8123.1 folds comparing to the sensitive cell line CCRF-CEM. After treatment of brassinolide under the concentration of 0.001 - 10.0 microg x mL(-1), the resistance of CCRF-VCR was reversed partly with the reversing folds respectively as 4.4 - 11.6. The intracellular accumulation of rhodamine 123 was significantly reduced in the resistant cells. After treatment of brassinolide, the accumulation increased, the level of fluorescent dye was situated between resistant cells and sensitive cells. No alteration of the catalytic activity of topoisomerase II was found among three groups. The level of protein expression of p53 in resistant cells was higher than that of sensitive cells. After brassinolide treatment, the expression of p53 in CCRF-VCR cells restored to the level of sensitive cells. CONCLUSION: Brassinolide could effectively reverse the resistance of CCRF-VCR cells by inhibiting the effusion of drug transported by P-glucoprotein. To down regulate the abnormal expression of p53 maybe one of the mechanisms of reversing MDR for brassinolide.

Brassica rapa↗

PubMed2005

[Resection of carotid body tumor under interrupted block of common carotid artery].

7 patients with carotid body tumor (CBT) were evaluated by DSA preoperatively. Carotid artery (CA) blocking test was carried out under local anesthesia before operation. With CA blocked temporarily, tumors were resected under general anesthesia after the test was normal. Meanwhile some cases underwent restoration with CA repair, end-to-end anastomosis or artificial vascular grafting. No case underwent internal bypass. CA was blocked 2 to 4 times in operation. The average blocking time of CA was 22 minutes and the longest blocking time of that reached 28 minutes. The average blood loss of cases without embolization preoperatively was 1100 ml, cases with embolization was 480 ml. 3 cases had nerve complications. DSA is of important value in the diagnosis and treatments of CBT. Temporary blocking artery method can help to judge when to use internal bypass, make operation easy, decrease blood loss and nerve complications.

Blood Loss, Surgical↗

PubMed2005

[Clinical study on laser therapy of the venous malformations and hemangioma in oral and maxillofacial regions].

OBJECTIVE: To try to find the best method of laser therapy for the management of venous malformation and hemangioma in oral and maxillofacial regions. METHODS: From June, 1999 to July, 2002, 2 481 cases of venous malformations and hemangiomas were treated by several kinds lasers in our department. The lesions included port-wine stains, venous malformations, telangiectasia and hemangioma. The lasers used were continuous wave CO(2), Nd:YAG and Krypton lasers, pulsed dye laser and ultra-pulsed CO(2) lasers. The treatment modalities were direct irradiation, irradiation after surgical flap raising and photodynamic therapy. RESULTS: Follow up between 2 - 5 years revealed the treatment results as follows: excellent is 79.24%, good is 14.31% and poor is 6.45%. CONCLUSIONS: Laser therapy is one of the best method to treat venous malformations and hemangiomas. The key point is to apply different lasers properly.

Adolescent↗

PubMed2005

[Zygomatic implants anchorage for the rehabilitation of maxillary defects].

PURPOSE: Prosthetic reconstruction of the upper jaw in patients with extensive bone and soft tissue defects is still a significant challenge. This study evaluated the functional results of zygomatic implants and vascularized bone graft reconstruction of the maxillary defects in 4 patients. METHODS: Complex resections of the maxilla produced a three-dimensional defect in 4 patients. On the basis of an axial spiral CT data, anatomical models of natural size by CAD/CAM system was manufactured to enable preoperative measurements of relevant parameters. After tumor resection, reconstruction using the fibula or iliac osteocutaneous flap with titanium osseointegrated implants was performed. Maxillary and zygomatic measurements were also used to obtain information for installing 6 zygomatic implants and 7 dental implants. RESULTS: The bone from the fibula or iliac osteocutaneous flap was contoured to recreate the maxillary arch in 4 patients. The anatomical model and surgical palate was used for preoperative planning and intraoperative control of the insertion of 6 zygomatic fixtures after subtotal maxillectomy. The implants could be positioned precisely as preoperatively planned. CONCLUSIONS: The use of zygomatic fixtures after ablative tumor surgery with resection of the maxillary bone is valuable in providing new zygomatic buttresses that play a key role in the form of the midface. Maxillary rehabilitation can be further improved by using the vascularized bone graft and zygomatic implants. Reconstitutions of the buttresses system ensure a stable base for occlusion, which is essential to optimal functional and esthetic maxillary rehabilitation. Supported by Research Fund (No. 2004BA720A27) of National Tenth Five-Year Project.

Bone Transplantation↗

PubMed2005

[Digital geometry processing and its applications in maxilla and mandible reconstruction surgery].

A new method to fabricate exact-fit medical implants is proposed. Medical image processing and digital geometry processing are adopted for bone triangular mesh modeling from CT image series. After geometric operations such as decimation, defragmentation, cutting and mirroring are applied to the original triangular mesh, an RP model of same size as the bone is fabricated with LOM method. RP models are used for manufacturing exact-fit implants and they also serve surgery-guiding purpose. This novel technique has been applied in over 30 clinical cases, and it is proven to be practicable.

Humans↗

PubMed2005

[The research on 3-D maxillofacial soft tissue reconstruction by spiral CT].

PURPOSE: To evaluate the role of spiral CT in 3-D reconstruction of maxillofacial soft tissues. METHODS: Spiral CT was given to a patient who had his right ear absent. The data was recorded in DICOM format. Digital image was reconstructed on GE advantage workstation in SSD way. RESULTS: Spiral CT can quickly and precisely scan and reconstruct the whole head, the reconstructed images of facial soft tissues and apparatus were very clear, but the site of pupil can not display. CONCLUSION: Except for the pupils, spiral CT is a useful way for maxillo-facial soft tissue reconstruction. It can be widely used in hospitals.

Face↗

PubMed2005

[Evaluation of the speech outcomes in patients with unilateral maxillary defect rehabilitated with maxillary obturator prosthesis].

PURPOSE: Evaluation of the outcomes in 15 patients with unilateral maxillary defect before and after maxillofacial obturator prosthesis. METHODS: 15 patients with unilateral maxillary defect were included in this study, who received obturator prosthesis for maxillary rehabilitation. The pronunciation of the examined phonetics such as /a/, /o/, /e/, /i/, /u/ were transferred into CSL4400 before and after treatment. The mean value of the first, second, third formant were measured. Paired t test of SPSS11.0 was used for statistical analysis. RESULTS: There was statistically significant difference on F2 and F3 before and after treatment (P<0.05). After treatment the value of F3 was increased significantly. CONCLUSIONS: The soft palate was reconstructed after obturator treatment. The space between the nasal and oral cavity was sealed,through which a similar normal oral cavity was obtained. Except F1, F2 and F3 of all the vowels changed after treatment. Maxillofacial prosthesis can improve the speech function of patients with unilateral maxillary defect effectively.

Humans↗

PubMed2005

[Axial split osteotomy of free fibular flap for mandibular angle reconstruction: a clinical study].

PURPOSE: To introduce an axial split osteotomy of free fibular flap for mandible angle reconstruction and discuss its indications and surgical technique. METHODS: 16 patients underwent axial split osteotomy of free fibular flap(12 males and 4 females, aged from 23 to 62). 11 patients with benign tumors (8 ameloblastomas and 3 odontogenic keratocyst), 3 patients with osteoradionecrosis, and 2 patients with secondary mandibular deformity were included. The length of free fibular flap ranged from 10-17 cm (mean 14.6 cm). The length of the vascular pedicel ranged from 5-11 cm (mean 8.2 cm). The fibular flap harvested was performed in routine manner. After elevating the periosteum and performing minimal dissection at osteotomy site only, axial splitting was performed using an oscillating saw. The first osteotomy was made on the external surface of the fibula, perpendicular to the main axis of the bone down to the level of the medullary canal. The second osteotomy was made along the main axis of the bone. The length of this osteotomy was between 2 and 3 cm. The last osteotomy was made perpendicular to the internal surface at one junction of the anterolateral and posteromedial surfaces down to the medullary canal, as was done for the first osteotomy. Then the harvested flap was contoured, which was achieved by raising the two bone segments and fitting them together. The angulation was 120 degrees. RESULTS: 16 flaps were monitored by Doppler ultrasound postoperatively and examined by colored ultrasound 3 months, 6 months after operation. The results revealed that the recipient sites healed primarily without complications. CONCLUSIONS: Axial split osteotomy is a reliable technique with maximum contact surface for bone union, and less bone loss, which can lengthen the transplanted bone to a certain extent. It is suitable especially for reconstruction of the defect of the angle of the mandible.

Adult↗

PubMed2005

[A comparison of clinical and virological characteristics of 1686 cases of HBeAg-negative and HBeAg-positive chronic hepatitis B].

OBJECTIVE: To investigate the clinical characteristics of HBeAg-negative and HBeAg-positive chronic hepatitis B (CHB). METHODS: A total of 1686 hospitalized CHB cases were analyzed retrospectively. The serum ALT values, HBV DNA levels and hepatic inflammation and fibrosis were analyzed by their serum HBeAg status. RESULTS: Among the 1686 cases, 628 (37.3%) were HBeAg-negative and 1058 (62.7%) were HBeAg-positive. Compared with HBeAg-positive group, HBeAg-negative group had a lower serum ALT and HBV DNA levels. However, hepatic necroinflammation grading and fibrosis staging in HBeAg-negative group were more advanced than that of HBeAg-positive group. Irrespective to serum HBeAg status, patients with serum HBV DNA less than 10(5)copies/ml, had a lower hepatic necroinflammation activity. CONCLUSIONS: HBeAg-positive CHB is still the predominant form of CHB in Chinese patients. Compared with patients with low HBV replication, patients with active HBV replication had a higher hepatic necroinflammation activity. The liver histological grading and staging in HBeAg-negative CHB patients were more advanced than that in HBeAg-positive patients.

Adolescent↗

PubMed2005

[Repair and reconstruction of oral and maxillofacial defect--clinical analysis of 1973 cases].

OBJECTIVE: To compare the reconstructive method of oral and maxillofacial defect with free tissue flaps. METHODS: The clinical materials were collected from 1 973 reconstructive cases between January 2000 and June 2004 and analyzed in terms of the distribution of age, gender, disease type, defect location, reconstructive method and the incidence of vascular crisis of free flaps as well as success rate of free flap respectively. SAS 6. 12 was adopted for statistical analysis. RESULTS: A total of 1973 reconstructive cases included 764 in middle age (>45 years to < or =60 years, 38.72%), 527 in old age (>60 years, 26.71%), 450 young adults (>28 years to < or =45 years, 22.81%), 187 in young age (>14 years to < or =28 years, 9.48%) and 45 children (< or =14 years, 2.28%). The ratio of male to female was 1.5 : 1. The ratio of benign to malignancy lesion was 1 : 1.94. The tongue defect accounted for 20.63%, followed by mandibular defect(17.38%), parotid defect(13.74%), buccal defect(12.72%), maxillary defect (8.16%), oral pharynx defect (7.60%), floor of mouth defect (5.68%) and others (14.09%). Vascular free flap transfers accounted for 45.82%(904), followed by axial flap(38.17%, 753), random flap (10.19%, 201), a vascularized bone graft (1.52%, 30) and others(4.30%, 85). The most frequently used flap was the forearm flap(594 cases), followed by the fibula free flap(143 cases) and the pedicled pectoralis major myocutaneous flap(369 cases); these three flaps accounted for 56.06% (1106/1973). In 47 free tissue flaps (5.20%) having vascular crisis, 30 were saved (63.83%). The success rate of total free tissue flaps was 98.19% (923/940). CONCLUSION: The majority of reconstructive cases of oral and maxillofacial defects is the middle aged and the old aged male patients with malignancy. The tongue defect accounts for about one fifth of all the cases. The vascularized free flap has a high success rate, so it is a main method for reconstruction of oral and maxillofacial defects. The forearm flap, the fibular free flap and the pedicled pectoralis major myocutaneous flap are the main management for repairing oral and maxillofacial defects.

Adolescent↗

PubMed2005

[The research on maxillofacial soft tissue reconstruction by 3-D laser scanning].

PURPOSE: To evaluate the role of 3-D laser scanning on reconstruction of maxillofacial soft tissues. METHODS: 3-D laser scan was given to a patient who had his right ear absent and reconstruct the image. RESULTS: 3-D laser scanning can reconstruct facial soft tissue quickly and precisely, but the image of the ear was not very clear. CONCLUSION: In the living, laser scanning can reconstruct all the maxillofacial soft tissues except for the ear. It can be widely used in clinic and research.

Ear↗

PubMed2005

[The mechanic retention of the casting post with keeper in magnetic retentor overdenture].

PURPOSE: To reduce the cost of the fabrication of the magnetic retentor,and meet the clinical requirements, nonprecious alloy such as Co-Cr alloy was used to fabricate the magnetic retentor in overdenture , instead of the precious alloy. METHODS: A mandibular canine was chosen for root canal preparation in vitro. Thirty two resin posts were made in the same root canal with self-curing resin. The 32 resin posts were randomly divided into 4 groups. Among them,2 groups were fabricated with soft Co-Cr alloy, gold alloy(55.6%Au) respectively in vitro. Another 2 groups were fabricated with Co-Cr alloy, and the surface of the root casting post with keeper were treated with gold deposit and gold coating technique. After that, test of dislodgment force was done and one-way ANOVA was performed with SAS 6.2 software package. RESULTS: The dislodgment force of the root casting posts with keeper which were fabricated with the Co-Cr, Ni-Cr, and gold alloy had significant difference(P<0.01). While after surface treatment by gold deposit and gold coating technique on root casting posts with keeper that were fabricated with Co-Cr and Ni-Cr alloy, there was no significant difference in dislodgment force, compared with that of gold alloy. CONCLUSIONS: After surface treatment of the root casting posts with keeper which were fabricated with the Co-Cr and Ni-Cr alloy, the same clinical retentive effect can be obtained as the one that was fabricated with gold alloy.

Chromium Alloys↗

PubMed2005

[Study on synergic or antagonistic effects of different acupoint groups on vertebro-basilar insufficiency].

OBJECTIVE: To observe the synergic or antagonistic effect of needling acupoints Fengchi (GB 20) and Tianzhu (BL 10), and Jiaji C4-C6 (EX-B2) on vertebro-basilar insufficiency (VBI). METHODS: Self-control method was used and 20 cases of VBI were respectively treated with acupuncture at Fengchi (GB 20) and Tianzhu (BL 10), Jiaji (EX-B2). Their combination and the changes of vertebro-basilar artery's (VBA) systolic velocity of blood flow was detected. RESULTS: The VBA's systolic velocity of blood flow after acupuncture were increased in all the 3 groups (P < 0.05 or P < 0.01), with no significant difference among the 3 groups (P > 0.05). CONCLUSION: Acupuncture at Fengchi (GB 20) and Tianzhu (BL 10) or Jiaji (C4-C6 ) or their combination can increase VBA's systolic velocity of blood flow, improving blood supply of vertebro-basilar artery, but they have no synergic or antagonistic effects.

Acupuncture Points↗