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Biomedical subjects

M Li

Publications and source records attributed to M Li.

At least 667 records · Page 37Linked to original sources

[The investigation of children's Helicobacter pylori infection by 13C-urea breath test in Yangzhong area of Jiangsu province].

OBJECTIVE: Yangzhong area in Jiangsu province is one of the places in China with high gastric cancer incidence (73.19/1000,00). In order to investigate the relations between gastric cancer and helicobacter pylori infection rate. METHODS: 13C-urea breath test was conducted for 119 children aged from 4 to 12 years old. RESULTS AND CONCLUSIONS: Total H. pylori infection rate was 73.11%, and 81.08% for boys, 60.00% for girls.

Breath Tests↗

[Mutation induced by space conditions in Escherichia coli strains].

To study the mutagenesis of microorganism under space conditions, three Escherichia coli strains CSH108, A2 and A3, were flown on board the Chinese recoverable satellite (JB1 - B9611020) in Oct . 1996. Three ways of sample boarding were designed . After recovery, survival and frequency of lacI- mutation and Arg+ reversion were determined in the flight strains. The results showed that: E. coli strains could survive after the flight conditions. The lacI- mutation frequency of A3 strain in the biocabin was sixty - seven times that of the ground control, the Arg+ reversion frequency of CSH108 in the lead chamber, was ten times that of the ground control; and among the revertants the mutation frequency of non-sense suppressor increased remarkably. The results indicate that the space conditions may greatly enhance the mutation frequency of certain genes in the microorganism and may provide an effective method for microorganism breeding.

Arginine↗

[Effect of neurotoxin on spinal cord injury in rats].

OBJECTIVE: To elucidate the effect of neurotoxin, excitatory amino acid and neuropeptide on spinal cord injury post trauma. METHODS: We detected the changes of concentration of EAA, glutamate(Glu) and aspartate(Asp) at injured segment tissue after spinal cord injury. Changes in dynorphin DynA1-13, an endogenous opioid, immnoreactivity following traumatic spinal cord injury in the rat were examined. We observed the effects of Glu and dynorphin DynA1-13 administered intrathecally on function of spinal cord in rats and the effects of 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP), an antagonist of EAA receptor, and antisera against dynorphin administered intrathecally on secondary spinal cord injury. RESULTS: The concentrations of EAA and dynorphin DynA1-13 increased progressively along with the severity of injury, and were related to injury time. Glu exacerbated the extent of spinal cord injury. Dynorphin DynA1-13 administered intrathecally caused dose-related hindlimb paraplysis in rats, whereas CPP and antisera against dynorphin DynA1-13 were found to have protective effect on spinal cord injury. CONCLUSION: These findings further support the potential pathophysiological role of EAA and dynorphin DynA1-13 as neurotoxin in spinal cord injury.

Animals↗

[Lung autotransplantation technique in the treatment of stage III bronchogenic carcinoma].

OBJECTIVE: To perform a double sleeve right upper and middle bilobectomy with transposing the inferior pulmonary vein to the superior one stump in a lung cancer patient. METHOD: The "cut-down" lobe was immersed in heparin solution in vitro for 15 minutes. It took 15, 14 and 10 minutes to finish the anastomosis of pulmonary vein, bronchus, and artery. The pulmonary artery was blocked for 3 hours. Postoperatively, the patient underwent ventilation for 6 hours. RESULT: In the 5th day after operation, re-implanted lung inflated well, the chest tube was retreated, and the patient can walk around. The reconstruction of pulmonary vessels and airway was done by spiral CT, which demonstrated no stenoses of bronchi and the pulmonary blood perfused and returned very well 3 weeks after operation. Follow-up more than 6 months showed the patient had a good quality of life and resumed his work. CONCLUSION: It is indicated to apply the technique of lung autotransplantation for operation on the central bronchogenic carcinoma when the main bronchus or pulmonary artery involved by tumor is too long to perform the anastomosis in the double sleeve bilobectomy.

Bronchi↗

[Interventional endovascular therapeutic modalities of giant intracranial aneurysm].

OBJECTIVE: To treat 28 cases of intracranial giant aneurysms in the last 7 years and study the therapeutic methods and their effectiveness on this disease. METHOD: The cases of giant aneurysms were divided into several groups. The advantages and disadvantages of the methods were compared. The main modality of endovascular therapy was to use balloon to occlude the parent artery. RESULT: In the 16 cases treated by the proximal balloon occlusion, 13 were cured angiographically with complete obliteration of the aneurysmal sac and in 4 of them the aneurysms disappeared both on CT and MRI. No deterioration after operation was encountered with the exception of 2 deaths. CONCLUSION: Endovascular therapy can cure the intracranial aneurysms which were difficulty treated by direct open operation.

Adolescent↗

[Diagnostic value of serum creatine kinase MB in patients with cardiac damage after electric injuries].

OBJECTIVE: To investigate the incidence of cardiac damage and the diagnostic value of serum myocardial enzyme following electric injuries. METHOD: 32 patients with electrical contact injuries were evaluated by serial electrocardiograms (ECG), creatine kinase (CK) and creatine kinase MB isoenzyme (CK-MB) determinations. The patients were divided into two groups according to the ECG. RESULT: 17 patients showed abnormal ECG (Group A), and 15 normal ECG (Group B). Positive correlations were noted between CK, CK-MB and the size of electric burns. The difference of serum CK-MB and 1.1% of total CK (CK-MB in skeletal muscle) was defined as CK-MB difference. CK, CK-MB, CK-MB/total CK ratio and the CK-MB difference were significantly higher in group A than in group B (all P < 0.05). The CK-MB difference of 88% (15/17) patients in group A was more than 25 U/L, whereas that was 6.7% (1/15) in group B (P < 0.01). Six patients with CK-MB difference greater than 100 U/L had obvious cardiac damage. CONCLUSION: Cardiac damage is a common complication of electric injuries. The cardiac damage could be estimated by serum CK-MB, particularly by the CK-MB difference. The CK-MB difference might be a useful indicator for evaluating the severity of the cardiac damage.

Adolescent↗

[Surgical treatment of spinal dural arteriovenous fistulas].

OBJECTIVE: To discuss the operation modalities of spinal dural arteriovenous fistulae (SDAVFs) and treatment with anticoagulant agents after surgery. METHOD: The medical records, radiographic studies and operations of 23 patients with SDAVFs were reviewed. Laminectomy was performed at the level of the arterialized venous entry into the subarachnoid space in 18 patients with thoracic and lumbar lever AVFs, followed by coagulation, clipping and division of the vein. In 14 of 18 patients, the arteriovenous nidus in the dura was identified and obliterated by coagulation. The draining veins were interrupted at L(5) - S(1) level in 5 patients with sacral AVFs. Anticoagulant treatment was given in 13 patients. RESULT: Outcome was good in 20 patients and 2 of the 20 had transient postoperative neurological deterioration that reversed by anticoagulant agents. No changes were seen in 2 patients except one deteriorated. CONCLUSION: Surgical interruption of arterialized radicular-medullary draining vein of SDAVFs provides lasting occlusion of the fistula, and postoperative anticoagulant therapy can prevent thrombosis of the coronal venous plexus.

Adult↗

[Human trabecular cell culture in vitro].

OBJECTIVE: To search the method of human trabecular cell (HTC) cultured in vitro, which could provide the necessary condition of experimental study on primary open angle glaucoma. METHOD: Organ and tissue culture were taken to get the different passages of human trabecular cells. In the meantime, human scleral fibrous cells were also cultured to contrast with HTC in morphology. RESULTS: (1) It took rather shorter time to get HTC by using organ culture method than simple tissue culture. (2) The 3rd to 5th passage of HTC was the most stable growth period, at that time they could be used in experiment. CONCLUSION: Stable growth shape and characteristic HTC could be obtained by HTC culture in vitro.

Cells, Cultured↗

[The effects of epinephrine and adrenergic antagonists on adenosine 3', 5'-monophosphate level of bovine trabecular cells in vitro].

OBJECTIVE: To determine the effects of epinephrine (EPI) and adrenergic antagonists on adenosine 3', 5'-monophosphate (cAMP) level of bovine trabecular cells (BTC) in vitro. METHOD: (3)H-cAMP was used in protein binding assay for measuring the intracellular level of cAMP. RESULTS: (1) 10(-5) mol/L EPI induced a fold increase of cAMP in cultured BTC in vitro; (2) Timilol and ICI 118, 551 blocked efficiently the effect of EPI at a lower concentration (10(-6) mol/L). (3) Bisoprolol did not efficiently block the effect of EPI unless at high concentrations (>or= 10(-5) mol/L). CONCLUSION: The effects of EPI increasing outflow facility may be associated with its increase of cAMP in trabecular cells; BTC contains beta-adrenergic receptors, and beta(2)-adrenergic receptors are dominant.

Adrenergic beta-Antagonists↗

[An experimental study of human trabecular cell growth on a filter and hydraulic conductivity].

OBJECTIVE: To search a method of culturing human trabecular meshwork cells (HTC) on a filter support and provide a model to study the hydraulic conductivity of HTC in vitro. METHODS: The 3rd passage of HTC was cultured on a nylon filter, after that we measured the rate of different irrigation through the filter with HTC [Lp, microl/(min x mmHg x cm(2))]. RESULTS: HTC could continuously grow on the filter. The normal Lp was 10.45 microl/(min x mmHg x cm(2)). When the model was irrigated respectively by the solution containing epinephrine (EPI) and dexamethasone (DEX), the Lp value of HTC cultured in the same period was significantly higher than that of the normal group. However, after HTC exposed to DEX for a few days, Lp was significantly decreased. CONCLUSIONS: (1) Better information of hydraulic conductivity and the effects of medicine on HTC can be obtained from the dynamic filter model; (2) EPI can improve the conductivity of HTC, and DEX can do the same in early period.

Animals↗

[Culture of human trabecular meshwork cells and the cell characteristics of immunohistochemical studies].

OBJECTIVE: To look for better cultural methods in order to obtain numerous human trabecular cells in vitro for glaucoma experimental studies, and describe the immunohistochemical characteristics of the cells. METHOD: Human trabecular meshwork cells were cultured, then 4 monoclonal antibodies were used for immunohistochemical stains of the cultured cells. RESULTS: At the primary period, the growth of human trabecular cells was obviously slower than that of cows and pigs. The immunohistochemical stains showed that the cells presented positive reactions to neuronal specific enolase (NSE) and vimentin and negative reactions to factor VIII related antigen (VIIIR:Ag) and desmin. CONCLUSIONS: The culture of human trabecular meshwork cells in vitro needs more careful and better cultural conditions. The cells originally are derived from embryonic neural crest, not from mesodermal endothelium of blood vessels. There is middle filament vimentin and no desmin in the cells.

Cell Division↗

[The regulating effects of dopamine receptors on the level of adenosine 3, 5-cyclic monophosphate in bovine trabecular cells in vitro].

OBJECTIVE: To assay the regulating effects of dopaminergic agonists and antagonists on adenosine 3, 5-cyclic monophosphate (cAMP) level in bovine trabecular cells (BTC) in vitro. METHOD: H(3)-cAMP was used in protein binding assay to determine the level of cAMP in bovine BTC. RESULTS: Dopamine, a dopamine receptor agonist, and fenoldopam, a selective DA(1) receptor agonist, caused a fold increase of cAMP in cultured BTC in vitro. These effects were blocked by halporide, a non-selective dopamine antagonist, and SCH23309, a selective DA(1) antagonist, but not blocked by phenoxybenzamin, an alpha-adrenergic antagonist, and timolol, a beta-adrenergic antagonist. CONCLUSION: Bovine trabecular cells contain not only beta-receptors but also DA(1) receptors.

Animals↗

[Mandibular swing procedure for resection of pharyngeal and skull base tumors].

OBJECTIVE: To seek for a better approach for the resection of pharyngeal and skull base tumors. METHODS: The overall tumor distribution for the entire group was nasopharyngeal 2 cases, oropharyngeal 4, parapharyngeal space 5 and parapharyngeal infratemporal area 2 cases. All 13 cases of pharyngeal and skull base tumors had their tumors thoroughly resected via mandibular swing approaches. Five cases had retropharyngeal node dissections, 2 cases had unilateral modified radical neck dissections, 5 cases with defect oropharynx were reconstructed with the pectoralis major myocutaneous flap, 10 cases with malignant tumors had received adjutant radiotherapy after surgical procedures. RESULTS: Of the 13 cases, 10 were malignant, 3 were benign. The incision in 12 cases healed primarily, one case with malignant fibrocystic tumor got infective necrosis of pectoralis major myocutaneous flap, this case healed completely after more than two months. One case developed dysphagia postoperatively and was recovered by swallow training. One case had minimal occlusion disorder. All patients were followed up from 15 months to 3 years. Three cases with benign tumors achieved good clinical results and are living well. In the malignant group, one died of recurrence at 6 months postoperatively, one died of lung metastasis, 2 cases survived for 3 years, 2 for two years, 4 for one year. CONCLUSION: This procedure provides good exposure of the base of the skull, the pharynx and the parapharyngeal space as well as the clivus and upper cervical vertebrae; it allows dissection along the internal carotid artery and facilitates resection of the tumor en bloc. It provides operative safety and minimal morbidity.

Adolescent↗

[Cloning and sequence analysis of the gene encoding the partial region CS protein of a Plasmodium falciparum isolate from Yunnan].

AIM: Determining nucleotide sequence of the circumsporozoite protein partial gene of the Plasmodium falciparum PFD-3/YN (Yunnan of China) and finding out the differences of the CS gene sequence between Chinese Plasmodium falciparum isolate and other isolates. METHODS: The circumsporozoite protein gene fragment was amplified by polymerase chain reaction and cloned into M13 bacteriophage. M13-CSP single strand DNAs of the three positive clones were extracted respectively. Then, the nucleotide sequence of the CS gene fragment was determined by the dideoxy chain termination method. PCGENE software was used to compare and analyze the CS gene sequence of the six isolates. RESULTS: Different degrees of diversity of the CS gene sequences were found among P. falciparum PFD-3/YN and other isolates(T4, Wellcome, NF54, 3D7 and 7G8). A non-silent substitution at the nucleotide level being found in the P. f Th/Tc antigenic epitope region. CONCLUSION: There were differences in the CS gene sequence among P. falciparum PFD-3/YN and those of other isolates.

Amino Acid Sequence↗

[Human trabeculer cells in culture and cell identification].

PURPOSE: To establish the method of culturing human trabecular cells(HTCs) in vitro and to determine identifyng main points concerning cultured HTCs. METHODS: Trabecular meshwork, corneal and scleral tissue were collected from sixty-eight eyeballs of thirty-four human donors less than six years of age within 24 hours after death. The tissues were primarily cultured and the cells subcultured. Cultured cells were observed by light and electron microscopes. Fibronectin(FN), laminin(LN) and IV collagen (IV C) in extracellular matrix(ECM) of the cultured cells were immunohistocytochemically stained by S-P method. RESULTS: HTCs easily grew in the event of young donors and short-time drawing materials. Trabecular meshwork should be accurately separated. Techniques in primary culture, and time and proportion in subculture should be suitabled. Experimental studies should select the third to fifth passages. The growing characteristics, morphological features of cultured HTCs under light and electron microscopes differed from those of corneal and scleral cells adjoining them. Ultramicrostucture distinguished HTCs from corneal interstitial cells. ECM stained by S-P method distinguished HTCs from scleral fibroblast. CONCLUSIONS: These studies suggest that it is not difficult to culture HTCs in general culturing condition as long as the main points about culturing them are known-well. The identification of cultured HTCs must be combined with three aspects: the growing characteristics and morphological features of cultured cells under light and electron microscopes, and the immunohistochemical stained peculiarities of FN, LN and IV C in ECM of cultured cells. To establish the method of culturing HTCs in vitro and to determine identifyng main points concerning cultured HTCs become an essential condition and an important guarantee in order to investigate the pathogenesis and mechanism on primary open angle glaucoma(POAG) deeply.

Cells, Cultured↗

Unilateral acute idiopathic maculopathy.

PURPOSE: To discuss the fluorescein angiographic features and diagnosis as well as differential diagnosis. METHODS: In our hospital, we have found three cases of UAIM, one of them has eccentric maculopathy, another has papillitis, and the third associates with pregnancy. Each has characteristic clinical findings. We have made the diagnosis base on ophthalmoscopy and fluorescein angiography (FA). RESULTS: Three patients with UAIM have been experienced sudden unilateral decreased visual acuity. The significant changes on fundus are retinal pigment epithelium (RPE) thickening with neurosensory retinal detachment with in the macular area. FA showed early patchy hypofluorescence and hyperfluorescence at the level of the RPE. 'Bull's eye appearance may occur in the macular area after the acute stage of the disease. The clinical findings are similar to what the foreign report described. But there were no previous reports in China. CONCLUSION: We can establish the diagnosis on the base of clinical and fundus features associated with fluorescein angiographic findings. However, the etiology and pathology could not be identified. It required further research.

Acute Disease↗