Biomedical subjects

G Li

Publications and source records attributed to G Li.

At least 757 records · Page 42Linked to original sources

PubMed1996

Experimental study of right ventricular assist in acute right ventricular failing.

The efficacy of right atrial-pulmonary artery (RA-PA) bypass during acute right ventricular failure (RVF) produced by pulmonary artery constriction in dogs was examined in this study Control group (n = 7) was supported with conventional volume loading and inotropic therapy. In the experimental animals (n = 8), RA-PA bypass was initiated 5 min, after the onset of severe RVF. Three control animals died from refractory ventricular fibrillation within one hour of RVF. No animals in the experimental group died within two hours of RA-PA bypass, but the histological study of the lungs in these animals demonstrated peribronchial, perivascular and intraalveolar hemorrhage. Light microscopic and electron microscopic examination of the myocardial specimens of the right ventricular free wall displayed the myocardial structures and ultrastructures were maintained effectively with RA-PA bypass while irreversible myocardial injuries occurred in the control animals after two hours of RVF with conventional therapy. During the 2 hours of RA-PA bypass, the hemodynamic indices were also maintained better when compared to the control animals. It may be concluded, a roller pump right ventricular assist device effectively unloads the acute failing right ventricle, maintains systemic cardiac output, and significantly reverses the myocardial ischemia during right ventricular failure, but RA-PA bypass may induce pulmonary hypertension due to increased pulmonary vascular resistance secondary to pulmonary edema and interstitial hemorrhage.

Animals↗

PubMed1996

[Simultaneous rhinoplasty and blepharoplasty].

Simultaneous rhinoplasty and blepharoplasty are the commonest facial cosmetic operation. The paper presents 73 cases who underwent this procedure with satisfactory results from Jan. 1989 to Nov. 1993. The authors described operation steps, e.g., making lacuna in the dorsum, lengthening nasal columella, nasal tip plasty. It was emphasized that the pretarsal flap should contain complete network of the superficial fascia, and the soft tissue underneath be trimmed. All the dissection should be kept in the same cleavage, which would reduce intraoperative bleeding and postoperative edema.

Adolescent↗

PubMed1996

[Experimental study of circulatory dynamics following inhalation injury in dogs].

Early changes in respiratory and circulatory dynamics before and after steam-inhalation injury were made in a dog model were studied. The results showed that the resistance of the respiratory system was significantly higher 3 hours and 4 hours post injury than that before injury (P < 0.05), the compliances of both the lung 4 hours post-injury and the respiratory system 3 hours psot-injury significantly decreased (P < 0.05), and the heart rate markedly lowered (P < 0.01), and the cardiac output also decreased (P < 0.05) 2 hours after injury. It is suggested that the early changes in the respiratory and circulatory dynamics may be used as markers for the diagnosis and treatment of the inhalation injury.

Airway Resistance↗

PubMed1996

[The study of clinical pathology on bronchial hyperresponsiveness].

OBJECTIVE: To study mechanism of bronchial hyperresponsiveness (BHR) and the relationship between asymptomatic BHR and asthma. METHODS: Bronchial biopsies were taken through fiberoptic bronchoscope from 17 cases of asymptomatic BHR, 12 cases of chronic asthma with remission and 10 normal control subjects. Bronchial mucosas were investigated by light microscopy and transmission electron microscope. Analysed by morphometric technique for the granules in both eosinophils (EOS) and mast cells (MC). RESULTS: Airway allergic inflammation (AAI) existed in 9 cases (53%) with asymptomatic BHR. It was similar in bronchial mucosal pathologic changes to chronic asthma with remission. Inflammation existed in the other 8 cases (47%), but unlike AAI, there were no infiltration of EOS and MC in bronchial mucosa. CONCLUSIONS: The pathological changes of asthma in bronchial mucosa were existed in a part of patients with asymptomatic BHR.

Adult↗

PubMed1996

[Histochemical and electron microscopical study on mast cells in the stroma of thyroid tumours].

To understand the number and morphology of the mast cells of throid tumours stroma, the mast cells (MCs) of 62 cases of thyroid tumour stroma were studied histochemically and electron microscopically. The number of MCs was increased significantly in thyroid tumour as compared with that in normal tissues. The number of MCs between thyroid cancer and thyroid adenoma was of no difference. When stained with Alcian Blue-Safranin, MCs in the stroma of normal thyroid were blue whereas in the stroma of thyroid tumour both blue and red mast cells could be found. The ultrastructure of the granule of the MCs was homogeneous electron-dense, which was the characteristic feature of TMCs. Degranulation of MCs adjacent to tumour cells could be seen. The significance of MCs in the stroma of thyroid tumour was discussed.

Adenocarcinoma, Follicular↗

PubMed1996

[Epithelioid variant of malignant peripheral nerve sheath tumor].

Epithelioid variant of malignant peripheral nerve sheath tumor arising from deep soft tissue is an uncommon neoplasm, histopathologic features of which are usually not homogenous. The aim of this study was designed to investigate the relation between morphologic features and prognosis of the tumor. Twelve cases were studied with light microscopy, immunohistochemistry, and 7 cases were studied with electron microscopy. Histologically, there were three patterns: purely epithelioid (5 cases), mixed with areas of spindle cells (5 cases) and ossifying (2 cases). The results showed S-100 protein positivity and multiple cytoskeletal heterogeneity that included: (1) neuronal differentiation which indicated expression for NSE and neurofilament, and ganglion cell; (2) epithelial differentiation which revealed reactivity for Keratin, and desmosomes and tonofilament-like bundles in ultrastructural findings; (3) mesenchymal differentiation which manifested reactivity for vimentin, osteoid metaplasia, and rhabdoid phenotype. The present study indicates that the relation between the heterogeneity and the aggressiveness of the tumors is synchronous. Three of the patients with prominent heterogeniety died with clinical evidence of lung metastases within seven months to four years after diagnosis.

Adult↗

PubMed1996

[A morphometric study on hippocampus of epileptic rats induced by coriaria lactone].

This experiment was carried out with these rats were injected with 3.8 microliters (19 micrograms) convulsive dosage of coriaria lactone (CL) in the left cerebral motor cortex of the forelimb to induce acute focal epilepsy, while the other 5 rats as controls (no seizure) received normal saline solution of the same volume and at the same location. The brains were taken after seizuring for 60 min. The volume (water displacement method) and weight of the brain were measured. The brain was cut coronally and the structures of hippocampus were compared morphologically with those of the pair-matched control. The area of hippocampal formation was measured with paraffin section by test grid under 40x. The mean size (Feret's diameter) of pyramidal neurons in CA1 region was measured with semithin section by ocular micrometer under 1000x. The areal fraction of several organelles of the CA1 pyramidal cells was measured with EM negative film by magnifier. Under conditions of the consistent reference space, especially the size of CA1 pyramidal cells, the areal fraction of rough endoplasmic reticulum, lysosome and mitochondria increased significantly (P < 0.05) in epileptic rats. It indicated that their volume increased. The results show that certain ultrastructural changes have taken place after seizuring for 60 min.

Animals↗

PubMed1996

[On diagnostics of malignant meningioma and invasive meningioma].

We have made a clinicopathological study of 90 cases of malignant meningiomas and 18 cases of invasive meningiomas. The results show that the diagnostic features of malignant meningioma include increased cellularity, nuclear pleomorphism, tumorous giant cells, numerous mitotic figures, focal necrosis, cystic change and hemorrhage. The diagnosis of malignant meningioma can be more positively made when invasive growth, recurrence and metastasis are present. In making the diagnosis of invasive meningioma, both changes of benign meningioma and invasive growth should be present.

Adolescent↗

PubMed1996

[The relationship of non-Hodgkin's lymphoma with P16 protein expression].

The expression of P16 protein was examined in 45 cases of non-Hodgkin's lymphoma (NHL), 4 cases of reactive hyperplasia of lymph node (RHLN) and 6 cases of normal spleen with immunohistochemical staining. Positive reaction of P16 protein was observed in some lymphocytes of RHLN and splenic nodule and around splenic sinus. The positive rate of P16 protein expression in NHL was 37.8% (17/45). The positive rates of P16 protein expression for the low intermadiate- and high-grade malignancy groups were 66.7% (10/15), 37.5% (6/16) and 7.1% (1/14) respectively. There was a significant difference between the low malignancy NHL and the high malignancy NHL (P < 0.005) in expression rate of P16 protein. It suggests that P16 protein expression may be one of the important parameters in estimating the prognosis of patients with NHL.

Adolescent↗

PubMed1996

[T-cell receptor gene rearrangement analysis of midline malignant reticulosis: a PCR study of 14 cases].

Using PCR method, we analyzed the gene rearrangement of T-cell receptor chain (TCR-beta) in 14 cases of midline malignant reticulosis (MMR). Our results showed that there were non-germline, monoclonal rearrangements of TCR-beta in 12 of 14 cases of MMR (85.7%). In contrast, the same rearrangement pattern was found only in 6 of 10 cases of lymph node based T-cell lymphoma. The cases of reactive lymphoid hyperplasia were of a polyclonal rearrangement pattern. This study suggests that MMR is a monoclonal T-cell neoplasm and PCR method is a rapid, facilitated and useful method for the detection of clonalities of T-cell proliferations.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece↗

PubMed1996

[Early result comparison following mitral valve replacement with partial or entire subvalvular structure preservation].

21 patients after mitral valve replacement with partial subvalvular structure preservation and 20 patients with entire subvalvular structure preservation were compared with 26 patients after mitral valve replacement with entire subvalvular structure excision. We found that patients after mitral valve replacement with partial or entire subvalvular structure preservation had a more uneventful postoperative course with less inotropic therapy and more decreased left atrial dimension when compared to those with conventional mitral valve replacement. But the patients after mitral valve replacement with entire mitral structure preservation had more decreased left ventricular dimension and short hospital stay when compared to those of the other two groups. The authors suggest that mitral subvalvular structure should be preserved, and we especially recommend the procedure of intravalvular implantation of mitral prosthesis with entire mitral subvalvular structure preservation.

Adult↗

PubMed1996

[Translabyrinthine--transtentorial approach for removal of large acoustic neuromas].

In 30 consecutive patients with large acoustic neuromas, which were more than 4.0 cm in diameter, tumor excision was performed by a one-stage combined translabyrinthine-transtentorial approach. The tumors were totally removed in 29 patients (96.7%), without death. The facial nerve was preserved anatomically in 16 patients (53.3%), and functionally in 11 (36.7%). Main advantages of this approach include: (1) direct approach with a more extensive exposure; (2) identification of both the origin of the facial nerve at the brain stem or in the internal auditory canal: (3) minimal postoperative reaction; (4) combination with other approaches. A brief discussion is been made on operative technique, prevention of postoperative complications and facial nerve preservation.

Adult↗

PubMed1996

[The application of the expert system in prosthedontics].

In this study, we developed an expert system for designing of frame work of Removable Partial Denture by the method of Artificial Intelligence. Both of Quick Basic and Tuber C language are used in this program. This system consider more other relative factors in removable partial denture designing except the amount and position of missing teeth. Base the idea of multy-layer knowledge we divide the process RPD designing into different layers according to their logical relationships. So, this system could imitate better the expert of prosthedontics to do the clinical examination, diagnosis, treatment plan and denture designing. There are 11 modules in this system totally. They are used to accomplish the case register, first visit examination, treatment plan, abutment examination, denture designing, biomechanic analysis of abutment, reference, explanation and etc. We used this system for 20 partial edentulous patients and compared the results with the designing plans of expert of prosthedontics, the rate of conformity is 83.6%.

Denture, Partial, Removable↗

PubMed1996

[Application of PCR-SSCP technique in detection of rpoB gene mutation in rifampin-resistant Mycobacterium tuberculosis].

OBJECTIVE: To evaluate rpoB gene mutation in rifampin-resistant Mycobacterium tuberculosis and its relationship with rifampin resistance. METHODS: Forty clinical isolates of Mycobacterium tuberculosis were analyzed by PCR-SSCP technique, with H37Rv reference strains as control group. RESULTS: The sensitivity of amplication products of 411bp and 258bp were found to be 5 pg/microliters, 500 organisms per milliliter and 1 pg/microliter, 500 organisms per milliliter respectively. rpoB gene belongs to genus specificity. Characteristics of SSCP graph of 258bp fragment: Ten sensitive strains were the same as H37 Rv. Thirty strains of rifampin-resistant or multidrug resistance, including rifampin, were different from H37Rv except for three strains. Positive rate was 90%, while specificity 100%. CONCLUSIONS: Results showed that PCR-SSCP technique could detect rPOB gene mutation, which might associate with rifampin resistance and be helpful to rapid detection and research of rifampin-resistant Mycobacterium tuberculosis.

Antibiotics, Antitubercular↗

PubMed1996

[DNA replication and cellular proliferation in the noise damaged basilar papillar of chicks].

An acoustic trauma model for study of the repair of the auditory epithelia was established in postnatal 8-14 days chicks. The animals were continuously exposed to the wide band noise at 115 dB (A) for 72 hours. The tracer of DNA replication-[3H] thymidine (3H-dR) was given in vivo or in vitro during or after exposure. The basilar papilla were cultured and processed with autoradiographic technique. The results demonstrated that at 48 hours following initial labelling of tracer, the incorporation of 3H-TdR was found over the nucli of supporting cells (or precursor cells) in the injured region of basilar papilla. The labelled hair cells appeared at 96 hours near the labelled supporting cells. Until the fifth to sixth days of culturing, the regenerated hair cells were still immature morphologically. No sign of labelled hair cells were detected in the control animals. Our findings indicated the potential capability of cellular proliferation and DNA replication in damaged auditory epithelia in vitro. Some kind of supporting cells in damaged region could be the precursors for regenerating hair cells. The positive cells labelled with 3H-TdR migrated to the surface of basilar papilar and differentiated into hair cells eventually. Therefore, it could be speculated that a homogeneous relationship may exist between labelled supporting cells and labelled hair cells.

Animals↗

PubMed1996

[Studies on the fine structures of inner ear vessels in guinea pigs].

In order to investigate the characters of inner ear vessels using the microvascular corrosion casting technique and scanning electron microscope the three-dimensional spatial picture of the vessels in cochlear basilar membrane, utriculus, sacculus and three ampullae of guinea pig were observed. It was found that arteriole coils were present in the modiolus ampullae, utriculus and sacculus. The length of arterioles was therefore prolonged and could keep the blood supply in inner ear stable. The possibility of blood coagulation in these segments increased because the blood flow became slower here. Another character was that the capillary networks appeared denser in stria vascularis and central part of the crista, whereas the vessel meshes in basilar membrane of cochlea and in planum semiculatum of ampullae were looser. These findings suggested that the metabolism in stria vascularis and central part of the crista would be more prosperous than that in the basilar membrane and planum semiculatum of ampullae.

Animals↗

PubMed1996

[Effects of growth factors on the survival status and the neurite regeneration of auditory neurons in vitro].

To confirm the biological effects of peptide growth factors on auditory neuron (AN) in vitro, the influence of NFG and bFGF on the survival status and the neurite regrowth of dissociated primary AN in postnatal chicks was studied with serum-free culture technique and cytologic quantitative method. The results demonstrated that the growth of non-neuron elements such as Schwann's cell was predominant in the earlier stage of culture. The neurite regrowth (bipolarity or unipolarity) of AN was observed at 24 hours after seeding. The growth rate increase during 48-72 hours in the surviving AN. These findings indicated that both growth factors exerted direct neuronotrophic effect on dissociated AN in vitro. NGF and bFGF acted in cooperation to promote the axon regeneration of AN. The concentration-dependent effect of NGF on neurite regrowth and neurone survival was found in the present study. The biological mechanism of NGF and bFGF on AN in vitro has been discussed.

Animals↗

PubMed1996

[Determination of puerarin in gegen ginlian tablets by RP-HPLC].

A quantitative method was developed for the determination of puerarin in Gegen Qinglian Tablets by reversed phase HPLC. Chromatographic conditions included column ODS-C18, column temperature: 35 C, UV detector: 250 nm, mobile phase: EtOH-H2O (23:77), flow rate: 1 ml/min. The number of theoretical plates calculated for puerarin peak was no less than 2000. The standard curve was linear in the concentration range of 5-80 micrograms/ml, and the correlation coefficient was 0.9999. The average recovery and the relative standard deviation were 97.6% and 1.8% respectivily.

Chromatography, High Pressure Liquid↗