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Biomedical subjects

Qiang Chen

Publications and source records attributed to Qiang Chen.

82 records · Page 5Linked to original sources
PubMed2002

Mitral valve surgery for acute papillary muscle rupture following myocardial infarction.

BACKGROUND AND AIM OF THE STUDY: Acute papillary muscle rupture (PMR) is a rare but fatal complication of myocardial infarction (MI). Surgery represents the best treatment option, but carries a high risk. Our experience of emergency mitral valve surgery in patients with acute PMR following MI during the past 22 years is reviewed. METHODS: Between 1978 and 2000, 33 patients (20 males, 13 females; mean age 64 years; range: 46-80) underwent emergency surgery for acute post-infarct PMR in our institution. The site of MI was anterior in three patients and inferior in 30. Preoperatively, 17 patients had an intra-aortic balloon pump (IABP) inserted, 26 were on inotropic support, and 17 were ventilated. Twenty patients (61%) underwent concomitant coronary bypass grafting (CABG). The valve was replaced in 31 patients and repaired in two. Mean (+/- SD) duration of follow up was 63+/-54 months (range: 0-183 months). RESULTS: Early mortality (in-hospital) was 21% (n = 7). Factors associated with significant risk of early mortality included raised preoperative serum creatinine (p = 0.02), need for preoperative inotropic support (p = 0.03) and preoperative ventilation (p = 0.03). Raised preoperative serum creatinine remained significant on multiple logistic regression (p = 0.04). Postoperatively, 21 patients required an IABP. Mean duration of intensive care unit stay was 4+/-2.5 days (range: 0-10 days). Survival, including in-hospital mortality, at one, five and 10 years was 75+/-7.4, 65+/-8.6 and 32+/-9.7%, respectively. Four patients required valve-related reoperation (three for a paraprosthetic leak, one for failed repair). CONCLUSION: Patients with acute post-infarct PMR present in a severely compromised state. Early mortality is high, but the intermediate outcome is encouraging for operative survivors.

Aged↗
PubMed2002

[Measuring human arm motion parameters based on high-speed camera].

A sensing method based on high-speed camera is proposed to recognize human arm motion in this paper. A sensing system for human arm motion was established. A fast image processing algorithm was developed to accurately extract marker positions in the image. Angle parameter results were further improved with the instantaneous joint center principle. The human motion information results can serve as the research references of medical treatment, gym, bionics, and so on. The sensing method can also be applied to other fields of the human motion recognition.

Algorithms↗
PubMed2002

[Attachment and growth of cultured fibroblast cells on chitosan/PHEA-blended hydrogels].

The chitosan/PHEA-blended hydrogels were prepared from PHEA and chitosan in various blend ratios. The water contents of the hydrogels were in the range of 50%-80% (wt). The attachment and growth of fibroblast cells(L929) on the hydrogels were studied. The results indicated the PHEA content in hydrogels has great effect on cell attachment but has little effect on the growth of L929 cells.

Animals↗
PubMed2002

[The application of arterialized venous digital island flap in fingertip reconstruction].

OBJECTIVE: To introduce an operation for fingertip reconstruction. METHODS: The vascularity of the reverse dorsal island flap is augmented by performing an arteriovenous anastomosis between the dorsal vein in the flap and a digital artery at the fingertip. The flap was used in ten patients for reconstruction of their fingertip defects. RESULTS: All the ten flaps survived and the appearance was good. CONCLUSION: The method is easy except for the necessity of performing standard microvascular surgery. The flap is a good option for repairing fingertip defects.

Adult↗
PubMed2002

[Comprehensive treatment of aquariculture water pollution by flocculant and complex strain].

In order to purify aquariculture water, decrease fish-disease and sewage discharge, the purification efficiency of several types of flocculants such as PFS, PDMDAAC, EM, and combining PFS-PDMDAAC, PFS-PDMDAAC-EM used for treatment of soft-shelled turlle pond water were studied, and optimal mathematical of water qualities effected by several types of purification method were established. The results showed that the comprehensive treatment had the best purifcation efficiency, the flocculation rate was above 98%, CODcr removed rate was above 95%, BOD5/CODcr of pond water and effluent decreased from 0.61 and 0.51 to 0.24 and 0.29 respectively, the biodegradable matter in waters have been effectively removed, when 30 mg.L-1 PFS, 0.5 mg.L-1 PDMDAAC and 30 ml.m-3 EM were added. The various major water qualities were keeded stabilization and had attained special aquariculture water quality standard. The water qualities of pond water and that of effluent were showed no difference, which had attained pollution-free discharge and ecological equilibrium aquariculture.

Ecology↗
PubMed2002

[Vector propagation algorithm based ECG simulation of bundle branch block].

The simulation of excitation propagation's process in human heart is one of the main aspects of ECG forward problem. The simulation results not only are the criterion of the simulation model's precision and reliability, but also have great value in researches and diagnoses. We performed the simulation of QRST waves of complete left bundle branch block (LBBB) and right bundle branch block (RBBB) in virtue of a vector propagation algorithm (VPA), which is accurate, efficient and applicable to anisotropic computer heart models. The simulation results accord with the actual QRST wave in clinical practice.

Algorithms↗
PubMed2002

[Separation and cryopreservation of cord blood mononuclear cells].

The influencing factors on cord blood storage after collection and mononuclear cell separation as well as cryopreservation were studied. The mononuclear cell are separated from blood after blood collection, then cryopreserved and washed after thawed. Results showed that the cord blood kept at 4 degrees C or room temperature less than 24 hours after blood collection, mononuclear cell separated by hydroxyethylstarch and 2 centrifugations, mononuclear cell cryopreserved with 50% DMSO and autoplasma from cord blood as protectives and washing the cells after thawing. In conclusion, the optimal project in this study can effectively preserve cord blood mononuclear cells.

Blood Preservation↗
PubMed2000

[A Nude Mouse Model for Human Umbilical Cord Blood Transplantation]

To evaluate the hematopoietic potentiality and the migration and homing routine of separated as well as cryopreserved umbilical cord blood hematopoietic cells, the BALB/cnu(+) mice were used to establish a murine model. This can prepare for the clinical transplantation and the establishment of a large-scale cord blood bank. The result indicated that the hydroxyethyl starch (HES) sedimentation and DMSO step-by-step cryopreservation procedure resulted in only less losses of hematopoietic progenitor cells and also unharmful to the hematopietic potentiality. We can found evidence for successful transplantation in each mouse which received (1.0 - 2.0) x 10(7) separated or cryopresered hematopoietic cells from cord blood, which lasted for about fifty days. The results demonstrated that (1) HES sedimentation and DMSO cryopreservation procedure can keep the hematopoietic potentiality of cord blood, and so can be used to clinical transplantation or establishment of a cord blood bank; (2) Rich hematopoietic stem cells in human cord blood can cross the xenogenetic barriers and successfully engraft mice; (3) The hematopoietic cells migrated among bone marrow, liver, spleen, lung and kidney in the mice and homed to bone marrow by the end. Cryopreservation may influence the adhesion molecule on the hematopoietic cells and the homing behaviour, but not influence their hematopoietic potentiality.

Journal Article↗
PubMedDate not supplied

Class V lupus nephritis: a clinicopathologic study in 152 patients.

BACKGROUND: Class V lupus nephritis (LN) can be divided into two subgroups according to the 1995 WHO modified classification, but the difference in clinical characteristics between these subgroups is not well known. METHODS: We classified 152 patients with Class V LN, confirmed by renal biopsy, into two subgroups (61 Class Va, 91 Class Vb), and enrolled 488 patients with Class IV as controls. The clinical manifestations, serologic results and prognosis were compared for Classes Va and Vb. RESULTS: The incidence of hypertension and anemia in Class Vb patients was significantly higher than in Class Va (38.5% vs 21.3%, 72.5% vs 52.5%, p<0.05). The incidence of hematuria and renal insufficiency in Class Vb was 64.8%and 15.4%, which was higher than Class Va (44.2% and 3.3%), but lower than Class IV (89.1% and 35%), p<0.05. The percentage of patients with positive anti-dsDNA antibody and hypocomplementemia in Class Vb tended to be higher than Class Va (35.2% vs 26.2%, 50.6% vs 31.2%). Repeated renal biopsies in 24 patients (11 Class Va, 13 Class Vb) showed that eight Class Vb patients had "transformed" to Class IV LN, while only two Class Va patients did (p<0.05). In three Class Va patients serum creatinine doubled during follow-up, but none of them progressed to end-stage renal disease (ESRD). In Class Vb serum creatinine doubled in ten patients, and three progressed to ESRD. CONCLUSIONS: The renal injury and extrarenal manifestations of Class Vb patients were severer than Class Va. Class Vb patients were more likely to shift to Class IV LN, and the prognosis was poorer than for Class Va.

Adult↗