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Biomedical subjects

Jun Zheng

Publications and source records attributed to Jun Zheng.

At least 37 records · Page 2Linked to original sources
PubMed2004

The internet-based knowledge acquisition and management method to construct large-scale distributed medical expert systems.

The Internet offers an unprecedented opportunity to construct powerful large-scale medical expert systems (MES). In these systems, a cost-effective medical knowledge acquisition (KA) and management scheme is highly desirable to handle the large quantities of, often conflicting, medical information collected from medical experts in different medical fields and from different geographical regions. In this paper, we demonstrate that a medical KA/management system can be built upon a three-tier distributed client/server architecture. The knowledge in the system is stored/managed in three knowledge bases. The maturity of the medical know-how controls the knowledge flow through these knowledge bases. In addition, to facilitate the knowledge representation and application in these knowledge bases as well as information retrieval across the Internet, an 8-digit numeric coding scheme with a weight value system is proposed. At present, a medical KA and management system based on the proposed method is being tested in clinics. Current results have showed that the method is a viable solution to construct, modify, and expand a distributed MES through the Internet.

Computer Systems↗
PubMed2004

Signal peptide of potato PinII enhances the expression of Cry1Ac in transgenic tobacco.

The modified Cry1Ac was expressed in transgenic tobacco plants. To allow secretion of the Cry1Ac protein into the intercellular space, the signal peptide sequence of potato proteinase inhibitor II (pinII) was N-terminally fused to the Cry1Ac encoding region. Expression of Cry1Ac in transgenic tobacco plants was assayed with ELISA. The results showed that pinII signal peptide sequence enhanced the expression of Cry1Ac protein and led to the secretion of the Cry1Ac protein in transgenic tobacco plants. GFP gene was also fused to the signal peptide sequence and transformed to tobacco. The results of fluorescent detection showed that GFP had localized in the apoplast of transgenic plants.

Amino Acid Sequence↗
PubMed2004

Development of thyroid-stimulating hormone beta subunit-producing cells in the chicken embryonic pituitary gland.

In previous studies, the distribution of thyrotropes in the chicken pituitary gland has been analyzed by immunohistochemistry using heterologous antibodies. In this study, we examined the distribution of thyroid-stimulating hormone beta subunit-immunopositive (TSHbeta-ip) cells and the expression of TSHbeta mRNA in the pituitary glands of chicken embryos by immunohistochemistry using a specific antiserum to the chicken TSHbeta, in situ hybridization and RT-PCR. Immunohistochemical and morphometric analyses revealed that the TSHbeta-ip cells first appeared on embryonic day 10 (E10) in the pituitary gland and were mainly distributed in the cephalic lobe and that the cell density on E20 was almost 4 times greater than that on E10. The chicken TSHbeta-ip cells could be classified into two types based on morphological characteristics: round-shaped cells and club-shaped cells, which have long cytoplasmic processes. In situ hybridization analysis revealed that TSHbeta mRNA-expressing cells were expressed from E9 in the cephalic lobe and that the extent of TSHbeta mRNA-expressing cells coincided with that of TSHbeta-ip cells. RT-PCR also showed that TSHbeta mRNA was expressed from E9 and that Pit-1 mRNA was expressed from E5. These results clearly demonstrated that the expression of chicken TSHbeta mRNA starts on E9, that TSHbeta-ip cells appear on E10, mainly in the cephalic lobe, and that TSHbeta-ip cells can be classified into two cell types (round- and club-shaped cells).

Animals↗
PubMed2004

Development of gonadotropes in the chicken embryonic pituitary gland.

Although a number of immunohistochemical studies have been carried out on the differentiation of chicken gonadotropes during embryogenesis, the temporal and spatial properties of appearance of gonadotropes are not clear. In this study, we studied the appearance and morphological characteristics of gonadotropes in the embryonic and adult chicken anterior pituitary glands using RT-PCR, in situ hybridization and immunohistochemistry. For this purpose, we raised specific antisera against chicken follicle-stimulating hormone beta-subunit (cFSHbeta) and chicken luteinizing hormone beta-subunit (cLHbeta) based on each putative amino acid sequence. RT-PCR analysis revealed that cFSHbeta mRNA was expressed from embryonic day 7 (E7). Chicken FSHbeta mRNA-expressing (-ex) and -immunopositive (-ip) cells started to appear in the ventral part of the caudal lobe in the anterior pituitary gland at E8. Chicken LHbeta-ip cells were also first observed there at E8, but cLH mRNA expression was confirmed from E4 by RT-PCR analysis. The distribution of these chicken gonadotropin-ex and -ip cells spread from the ventral part to dorsal part in the caudal lobe around E10 and subsequently expanded to the cephalic lobe from E12 to E20. These cells were morphologically classified into two types (round- and club-shaped cells). It was found that the density of gonadotropin-ip cells in the caudal lobe was always higher than that in the cephalic lobe throughout the period of development. To the best of our knowledge, this is the first report focusing on the differentiation of chicken gonadotropes by assessment of both protein and mRNA of chicken gonadotropin.

Amino Acid Sequence↗
PubMed2004

[Multi-channel cochlear implants in patients with Mondini malformation].

OBJECTIVE: To describe clinical experiences with multi-channel cochlear implantation in patients with Mondini malformation. METHODS: Among 300 patients who received multi-channel cochlear implants from 1996 to 2002 in Beijing Tongren Hospital, 15 patients were diagnosed with Mondini malformation. A retrospective analysis was performed dealing with the surgical techniques, mapping and rehabilitations characteristics after surgery. 15 patients with normal cochlear structure are consider as control group. RESULTS: Gusher is found more common than the normal cochlear implantation, most of them are serious. The electrodes are inserted in the "cochleostomy" in full length of 13 Patients, 2 pairs of electrodes remains outside of "cochleostomy" in 2 patients. No serious complications occurred after implantation. All patients have auditory sensations. The impedance of the electrodes, the T level, C level and the hearing threshold are similar with the normal cochlear implantation group. The results have no significant difference in compare with normal cochlear group(P > 0.05). CONCLUSION: Multi-channel cochlear implantation could be performed safely in patients with Mondini malformation. The primary outcome for patients with Mondini malformation are similar to those with normal cochlear structure following the multi-channel cochlear implantation.

Adolescent↗
PubMed2004

[The psychophysical tests in different age of patients with cochlear implants].

OBJECTIVE: The aim of this research is to analyse and compare the psychophysical tests in different age of patients with a cochlear implant. METHOD: One hundred and seventy patients with Nucleus CI24M cochlear implant system participated in this study. The patients were divided into four groups according to their age. They were group A (<3 year), B(3-<6 year) C(6-12 year) and D(>12 year). The psychophysical tests included T and C-Level evaluation. RESULT: C-Levels of each electrode (except electrode No. 20) were significantly different between group A and D at the time of one month after switch-on (P<0.01, P<0.05 for the No. 2, 18, 19, 21, 22 electrode). The normalized differences between used C-Levels and C-Levels for group D were significantly higher than the other three groups at the switch-on session (P<0.01, P<0.05 between group D and C). The normalized differences between used C-Levels and C-Levels were significantly different for the group A and D at one week after first programming session (P<0.05). CONCLUSION: T and C-Level for different age groups were different. The normalized differences between used C-Levels and C-Levels were significantly different among the four groups in the few weeks after switch-on.

Adolescent↗
PubMed2004

[Innovation and practice of college educational system in otorhinolaryngology].

OBJECTIVE: A series of educational innovation was performed in order to resolve the difficulties and conflict in the education of otorhinolaryngology of medical college. METHOD: The college educational system of otorhinolaryngology was established and put in practice in four grades of medical undergraduate students of 1997-2000 grade. RESULT: The scores and ability of medical students in otorhinolaryngology are improved significantly. Educational supervisors and the managers give high appreciation to the educational innovation of otorhinolaryngology. It was demonstrated that the innovated educational system is satisfactory for the college education of otorhinolaryngology. CONCLUSION: The innovated college educational system of otorhinolaryngology afford a good way to solve the difficulties and conflict in the college education of otorhinolaryngology. It is also valuable to other subjects in the clinical medical education of college education system.

Education, Medical, Undergraduate↗
PubMed2004

[Cochlear implantation in patients with inner ear malformations].

OBJECTIVE: To describe clinical experiences with multi-channel cochlear implantation in patients with bilateral inner ear malformations. METHODS: Among 410 patients who received multi-channel cochlear implantations from 1996 to 2004 in Beijing Tongren Hospital, 82 patients were diagnosed with inner ear malformations and implanted. A retrospective analysis was performed about the surgical characteristics and mapping characteristics after implantation. RESULTS: (1) All patients had auditory sensations. (2) Gusher was more common than the normal cochlear implantation. (3) The electrodes were inserted in the "cochleostomy" in full length of 80 Patients, but 2 pairs of electrodes remained outside of "cochleostomy" in 2 patients. (4) No serious complications occurred after implantation. (5) The impedance of the electrodes, the T level and C level were similar with the normal cochlear implantation. The results had no significant difference in compare with normal cochlear group (P > 0. 05). (6) The abilities of speech discrimination and spoken language were improved through rehabilitation. CONCLUSIONS: The cochlear implantation can be performed safely in inner ear malformations. The outcome of hearing rehabilitation for patients with inner ear malformations are similar to those children with normal cochlear structure followed the multi-channel cochlear implantation.

Adolescent↗
PubMed2004

[Innovation of the curriculum system of otorhinolaryngology and its impact on education of capable medical students].

OBJECTIVE: The impact of the curriculum system innovation of otorhinolaryngology in the education of capable medical student was investigated. METHOD: The curriculum system of otorhinolaryngology in our college was innovated. The innovated curriculum of otorhinolaryngology was put in practice in 3 grades of undergraduate students and 2 grades of seven-year education system students. RESULT: The clinical practice ability and the mast of the knowledge of otorhinolaryngology were improved significantly. CONCLUSION: The principle of the curriculum system innovation of otorhinolaryngology in our college is effective and, therefore, valuable in education of potential and capable medical students for other subjects of clinical medicine.

Curriculum↗
PubMed2004

[Myocardial ultrastructural changes in rats following different levels of acute +Gz exposure].

OBJECTIVE: To observe the effects of different levels of acute +Gz exposure on myocardial ultrastructure of rats and provide experimental basis for further development of anti-G measures. METHOD: Twenty male Wistar rats were randomly divided into 4 groups (n=5): normal control group, +20 Gz group, +10 Gz group and +5 Gz group. Profile of the centrifuge +Gz exposure was trapezoidal, in which +20 Gz lasted for 30 s, +10 Gz for 1.5 min. +5 Gz exposure was repeated for 3 times with 30 min interval and each for 1.5 min. Myocardial tissue of left ventricle was sampled for transmission electron microscopy 5 h after exposure. RESULT: +20 Gz and +10 Gz exposure caused obvious edema of myocardial and endothelial cells, myofibril disorder and injuries of mitochondria and nucleus. Breaks of myocardial fiber, formation of contraction bands and rupture of mitochondria were also observed in +20 Gz group. In +5 Gz group, there was still slight edema of myocardial and endothelial cells, while organic changes of myocardial ultrastructure were not observed. CONCLUSION: High +Gz exposure can cause myocardial ultrastructural injury in rats. Slight reversible injured response can also be observed in myocardial cell after repeated moderate level of +Gz exposure. This indicates that attention should be paid to the study of the effect of high +Gz on heart in pilots.

Acceleration↗
PubMed2003

Characterization of PTM5 in aspen trees: a MADS-box gene expressed during woody vascular development.

The vascular component of trees possesses some of the most specialized processes active in the formation of roots, stems, and branches, and its wood component continues to be of primary importance to our daily lives. The molecular mechanisms of wood development, however, remain poorly understood with few well-characterized regulatory genes. We have identified a vascular tissue-specific MADS-box gene, Populus tremuloides MADS-box 5 (PTM5) that is expressed in differentiating primary and secondary xylem and phloem. Phylogenetic analysis has shown that PTM5 is a member of the SOC1/TM3 class of MADS-box genes. Temporal expression analysis of PTM5 in staged vascular cambium and other tissues indicated that PTM5 expression is seasonal and is limited to spring wood formation and rapidly expanding floral catkins. Spatial expression analysis using in situ hybridization revealed that PTM5 expression is localized within a few layers of differentiating vascular cambium and xylem tissues as well as the vascular bundles of expanding catkins. Since many MADS-box genes are known to act as transcription factors, these results suggest that the coordinated expression of PTM5 with other vascular developmental genes may be a hallmark of the complex events that lead to the formation of the woody plant body.

Amino Acid Sequence↗
PubMed2003

Quantitative analysis of hydroperoxyl radical using flow injection analysis with chemiluminescence detection.

The hydroperoxyl radical (HO2) is one of the most abundant free radicals in the atmosphere, where it participates in a series of photochemical reactions that determine the fate of natural and anthropogenic emissions. In addition, HO2 is found in droplets and surface water as a result of photochemical formation and gas-phase scavenging. We describe a quantitative method for determining trace concentrations of HO2 radicals that exploits the chemiluminescence produced upon reaction with a synthetic analogue of luciferin from the crustacean Cypridina. The technique is linear at least up to 1 microM HO2(aq) and has a minimum detection limit of 0.1 nM. A unique feature of this analysis is a calibration method using stable aqueous HO2 standards produced in submicromolar concentrations using 60Co gamma-radiolysis. The advantage of this method in comparison to others in consideration of field deployment is its simplicity, low cost, and minimal size and power requirements. One intended application of this technique is the measurement of atmospheric HO2 radicals following collection into aqueous solution.

Animals↗
PubMed2003

[Cochlear implantation in patients with inner ear malformations, clinical analysis of 25 cases].

OBJECTIVE: To explore the clinical experience of multi-channel cochlear implantation in patients with bilateral inner ear malformations. METHOD: Multi-channel cochlear implantation was conducted among 180 patients from 1997 to 2001. Twenty-five of them, being with inner ear malformations, were given hearing and speech rehabilitation including sound detection, word discrimination, auditory comprehension and spoken language skill development. A follow-up lasting 4 - 24 months was conducted after the operation. A retrospective analysis was performed among these 25 patients to observe the surgical outcomes and mapping characteristics after surgery. RESULTS: (1) All patients restored their auditory sensations after the operation. (2) Stapedial gusher was found in 13 cases with inner ear malformations, especially those with Mondini malformation, much more frequently than among the patients with other malformations. (3) Most of the action electrodes were inserted in the "cochleostomy" in full length, only 2 pairs of them remained outside of the "cochleostomy". (4) No serious complications occurred after implantation. (5) The impedance of the electrodes, T level and C level were higher in the 25 cases than in the normal cochlear implantation, however, with the hearing similar hearing threshold. (6) After training, the abilities of speech discrimination and spoken language were improved in comparison with those before operation. CONCLUSION: The cochlear implantation can be performed safely in patients with bilateral inner ear malformations. The primary outcome of cochlear implantation in hearing rehabilitation is similar for both the patients with inner ear malformations and those with normal cochlear structure.

Adolescent↗
PubMed2003

[Treatment of hypopharyngeal stricture after total laryngectomy by interventional therapy with inner-cavity cradle].

OBJECTIVE: To investigate the main factors in the treatment of hypopharyngeal stricture after total laryngectomy by interventional therapy with inner-cavity cradle. METHOD: Nine patients of hypopharyngeal stricture after total laryngectomy accepted the interventional therapy with inner-cavity cradle. RESULT: The interventional therapy with inner-cavity cradle succeeded in 8 patients, the difficulty of swallowing was obviously improved immediately after the therapy. The therapy failed in 1 patient. The follow-up period lasted from 5 months to 36 months. For the 8 patients, the inner-cavity cradle helped them to overcome the difficulty of swallowing, gained more time for further treatment. CONCLUSION: A suitable inner-cavity cradle can extend the hypopharyngeal stricture after total laryngectomy, help the patient to overcome the difficulty of swallowing. The therapy is easy to perform, the effect is reliable. It can be a utility treatment for the hypopharyngeal stricture.

Aged↗
PubMed2003

[Cochlear implants in children with enlargement of vestibular aqueduct].

OBJECTIVE: To describe the clinical experiences with multi-channel cochlear implantation in the children with enlargement of vestibular aqueduct. METHOD: Fifteen patients were diagnosed with enlargement of vestibular aqueduct and received multi-channel cochlear implantation at Beijing Tongren Hospital. A cochleostomy was performed for all patients by a standard facial recess approach to anterior inferior to the round window niche. RESULTS: (1) Most of the electrodes were totally inserted in the cochlear, and gusher appeared in 6 implantations. (2) No serious complications occurred after implantation. (3) All patients have auditory sensations after implantations. (4) The hearing threshold in this series were similar to that of the normal cochlear implantation (the average threshold was 30 dB). (5) The rehabilitation concept was developed by Rehabilitation Research Center for Deaf Children in Beijing and Beijing Tongren Hospital. The training sessions included sound detection, word discrimination, auditory comprehension and spoken language skill development. The abilities of speech discrimination and spoken language were improved comparing with that of pre-operation. Two of the patients could go to the normal school after implantations. CONCLUSION: The outcome of hearing rehabilitation for children with enlargement of vestibular aqueduct were similar to those children with "normal" cochlear structure followed the multi-channel cochlear implantation.

Adolescent↗