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Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 361 records · Page 20Linked to original sources
PubMed2001

[Pharmacological study on the extracts from Typhonium flagelliforme Blume].

OBJECTIVE: To study the pharmacological action of Typhonium flagelliforme Blune(TFB). METHODS: Relieving a cough and eliminating expectoration were observed by strong aqua spray and pheol red determining methods. The antiasthmatic action was observed by whole spraying method. The analgesia and anti-inflammation were studied by the twisting test induced by acetic acid and ear swelling induced by xylene. The sedation was determined by autonomic action test. The toxicity of TFB was studied through the acute toxicity test in mice. RESULTS: All the water, alcohol and ester extracts of TFB could significantly decrease cough times, increase phenol red outage in trachea, prolong asthma incubation period, decrease twisting times, inhibit ear swelling and decrease autonomic action times. CONCLUSION: All water, alcohol and ester extracts of TFB have effects of relieving a cough, eliminating expectoration, antiasthmatic, analgesia, anti-inflammation and sedation. The maximum tolerances of TFB for acute toxicity were 720 g/kg(water extract), 900 g/kg (alcohol extract) 3240 g/kg(ester extract) respectively.

Analgesics↗
PubMed2001

Perceived discrimination and early substance abuse among American Indian children.

This study investigated internalizing and externalizing symptoms as potential mediators of the relationship between perceived discrimination and early substance abuse among 195 American Indian 5 through 8 graders from three reservations that share a common culture (e.g., language, spiritual beliefs, and traditional practices) in the upper Midwest. The findings indicated that, although perceived discrimination contributed significantly to internalizing symptoms among the adolescents, internalizing symptoms were unrelated to early substance abuse. Rather, the effects of perceived discrimination on early substance abuse were mediated by adolescent anger and delinquent behaviors. The results are discussed in terms of the consequences of perceived discrimination on the development of American Indian early adolescents.

Adaptation, Psychological↗
PubMed2001

Observation of wounding characteristics in dogs wounded by super velocity projectile.

OBJECTIVE: To understand wounding characteristics in dogs wounded by super velocity projectile with a purpose of providing a basis for prevention and treatment of such wounds. METHODS: A specially-made explosive gun was used to shoot aluminium bullet weighing 3.0 g and 1.4 g to injure both legs of dogs at velocities of 2330 m/s, 3200 m/s and 4250 m/s, respectively, and the soap specially made was also shot. At the same time, steel ball of 1.03 g was shot with a Type 53 smooth chamber gun at a speed of 1280 m/s. Within 30 min after wounding, debridement and pathological anatomy were performed and specimens were taken for light microscope observation. RESULTS: When the dogs were wounded by the 3 g bullet at speed of 2330 m/s, the entrance of the left leg was penetrated explosively with a defect area of 225 cm(2), and the femur trunk was also injured and the residual femur had comminution fracture. The exit of the right leg was blindly wounded with a defect area of 63 cm(2), but only the skin was not penetrated. Both testes and part pelvis were injured too. Under light microscope, degenerative myofibers and bleeding of the spatium between the myofibers could be found at the place 4 cm away from the wounding track. Furthermore, serious bleeding of the bladder and blood vessels of the brain could be observed. The lungs showed changes of blast injury. Vacuolar change was presented in the cytoplasm of hepatocytes. Injuries of the animals in other two experimental groups were similar to those described above, but the defect area of the wounded track was 124 cm(2) in the group of 4250 m/s. Injuries caused by the steel ball were milder than caused by the explosive gun. The volume of the residual cavity in the soap was 5000 ml. CONCLUSIONS: The super-velocity projectile causes destructive damage to the local tissues and multi-organ injuries. Therefore, the practical medical care needs not only amputation but also management of multi-organ injuries.

Animals↗
PubMed2001

Trauma-related xanthogranulomatous interstitial nephritis: a clinicopathological analysis.

OBJECTIVE: To investigate the pathogenesis, exact nature, histologic feature of xanthogranulomatous interstitial nephritis (XGIN) as well as its significance in clinical medicine. METHODS: The medical histories concerned were collected with diagnostic images including CT scanning, ultrasonography, intravenous urography (IVU) and laboratory data being synthesized by comparison with what was discover ed during operations and pathologic examinations. RESULTS: All patients were ever struck on their loins or backs by blunt violence over 4-12 years. The diseases were clinically diagnosed as "renal cancer" before, during and after operations, and treated with ra dic al nephrectomy. Located at cortical parts, the tumor focus had penetrated the renal capsules and invaded other organs. However, immunohistochemistry demonstrated that the lesions were xanthogranulomas, not tumors, in which there were stacks of foam cells and lymphocytes with vast extends of fibrotic tissues obliterating the cortical interstitial structures. Urinary tracts yielded no bacterium, obstruction or calculus. CONCLUSIONS: XGIN is likely to be one kind of immunologic mediated granuloma following blunt renal trauma. It is imperative to clarify pathogenesis and character of this lesion so as to find out any approach to diagnosis and cure of such an unusual nephropathy.

Adult↗
PubMed2001

[Sources analysis and contribution identification of polycyclic aromatic hydrocarbons in indoor and outdoor air of Hangzhou].

Twelve polycyclic aromatic hydrocarbons (PAHs) were measured in eight homes in Hangzhou during the summer and autumn in 1999. The sources of PAHs and the contributions of the sources to the total concentration of PAHs in the indoor air were identified by the combination of correlation analysis, factor analysis and multiple regression, and the equations between the concentrations of PAHs in indoor and outdoor air and factors were got. It was indicated that the factors of PAHs in the indoor air were domestic cuisine, the volatility of the mothball, cigarette smoke and heating, the waste gas from vehicles. In the smokers' home, cigarette smoke was the most important factor, and it contributed 25.8% of BaP to the indoor air of smokers' home.

Air Pollutants↗
PubMed2001

[The influence of flexible open-loop anterior chamber intraocular lens on the structure of ocular anterior segment].

OBJECTIVE: To evaluate the therapeutic effects and safety of flexible open-loop anterior chamber intraocular lens (FOAC-IOL). METHODS: By ultrasound biomicroscopy, the positions of the haptics of FOAC-IOL in 20 patients (20 eyes) and the relationships of the haptics with iris and anterior chamber angle structures were observed postoperatively to evaluate the impact of these lenses on the structures of ocular anterior segment. Follow-up duration was from 6 to 20 months. RESULTS: Among 40 IOL's haptics, twenty-six haptics were fixed at the recess of the chamber angle; and other fourteen haptics penetrated the iris and invaded into the ciliary stroma, which caused recurrent uveitis. There was 1 eye with eccentric lens. There were 8 eyes with anterior synechiae of iris, which were related to the haptics of intraocular lens. CONCLUSIONS: Ultrasound biomicroscopy works well in dynamic observation of the influence of intraocular lens on ocular anterior segment. The haptics of flexible open-loop anterior chamber intraocular lens should be modified.

Aged↗
PubMed2001

[Preparation of green fluorescent protein retrovirus and its application in mediating gene transfer into retinal pigment epithelial cells].

OBJECTIVE: To determine whether human retinal pigment epithelial (RPE) cells can be infected by retrovirus and modified by retrovirus-mediated gene transfer. METHODS: Recombination retroviral vector pLNCX-GFP (green fluorescent protein, GFP) was generated by inserting 780 bp GFP cDNA fragment into the MCS site of pLNCX. pLNCX-GFP was transfected into ecotropic packaging cell line PhiX-Eco and amphotropic packaging cell line PhiX-Ampho and PA317. Retroviral titer was tested by counting GFP expression of NIH3T3 cells. Then RPE cells were infected by using GFP retrovirus-containing supernatant. RESULTS: GFP was expressed and retrovirus was produced upon pLNCX-GFP being transfected into packaging cell line. The GFP retrovirus was able to infect primary cultured human RPE cells and immortalized RPE cell line. CONCLUSION: The retrovirus can introduce a foreign gene into RPE cells efficiently, thereby it can be used as an important tool to deliver gene into RPE for therapy of fundus diseases.

Cells, Cultured↗
PubMed2001

[The clinical effect of non-penetrating trabecular surgery with reticulated sodium hyaluronate implant for treatment of primary open-angle glaucoma].

OBJECTIVE: To evaluate the clinical effect of non-penetrating trabecular surgery (NPTS) with reticulated sodium hyaluronate implant in primary open-angle glaucoma (POAG). METHODS: NPTS with reticulated sodium hyaluronate implant was performed on 27 eyes of 25 patients with POAG. The procedure consisted of excising a deep scleral tissue including the external wall of the Schlemm's canal under a scleral flap without opening the anterior chamber, as the inner wall of the canal was left in place. Then placing a 3.0 mm x 4.5 mm x 0.5 mm or 3.5 mm x 3.5 mm x 3.5 mm reticulated sodium hyaluronate implant was placed under the flap, so that the aqueous humor may filter through the thin layer of trabeculocorneal membrane spontaneously without forming a flat chamber. The postoperative intraocular pressure (IOP), inflammation and filtering bleb were analyzed. All of patients undertook ultrasound biomicroscopy (UBM) and gonioscopy to evaluate the surgical site on the postoperative 2 weeks, 3, 6 and 9 months. The mean follow-up was (6.61 plus minus 2.47) months. RESULTS: The IOP decreased from a mean preoperative value of (26.36 +/- 9.02) mm Hg (1 mm Hg = 0.133 kPa) to a mean postoperative value of (14.18 +/- 3.51) mm Hg (t = 6.875, P < 0.05). The number of anti-glaucomatous medications, topical or systemical, was reduced from (2.96 +/- 1.43) sorts preoperatively to (0.77 +/- 1.07) sorts postoperatively. The visual acuity remained stable (no statistical difference with chi(2) test). Six eyes had elevated IOP after operation and were controlled by eyedrops or trabecular puncture with ND: YAG laser. A slight hyphema occurred in 4 eyes with small puncture during operation. The complications such as flat chamber, inflammation and choroidal detachment were not observed. The UBM showed that the sodium hyaluronate implant degraded and a transparent liquid space existed under the scleral flap in all of patients at postoperative 3 months. The gonioscopy showed that at the surgical site the thinner and semitransparent trabecular membrane and changes of a transparent cavity could be seen in 23 eyes. In the other eyes, at the site the trabecula was translucent. The filtering blebs were formed in 8 eyes. CONCLUSION: Non-penetrating trabecular surgery with reticulated sodium hyaluronate implant can effectively lower the IOP and reduce the sorts of anti-glaucomatous medications. The visual acuity may remain unchanged, and no serious complications commonly seen in the traditional trabeculectomy occur. The procedure is a new simple and effective one for the treatment of POAG.

Adolescent↗
PubMed2001

[The protective effects of Zn-metallothionein on severely scalded rats inflicted by oxygen free radicals].

OBJECTIVE: To investigate the protective effects of metallothionein (MT) on severely scalded rats inflicted by oxygen free radicals after delayed resuscitation. METHODS: Wistar rats inflicted by 30% TBSA III degree scalding injury were taken as the model. Fifty-Six rats were randomly divided into four groups, i.e. normal control, delayed resuscitation, MT treated and VitC treated groups. The changes in superoxide dismutase (SOD) and malondialdehyde (MDA) contents in plasma and subeschar edematous fluid were determined at 24 and 48 postburn hours with traditional indirect detecting method and electron spin resonance (ESR). Pathomorphological examination was simultaneously carried out for cardiac, hepatic, renal and intestinal samples. Plasma biochemical indices were determined at the same time. RESULTS: In delayed resuscitation group, SOD content decreased and the MDA contents increased in plasma and subeschar fluid obviously, with remarkable changes in the pathomorphology of all the internal organs and the blood biochemical indices. But in MT treating group, SOD content increased (P < 0.05) with decreased content of MDA (P < 0.05) and the pathomorphology and blood biochemical indices improved significantly when compared with those in delayed resuscitation group and VitC treatment group. CONCLUSION: MT treatment might be beneficial in the management of severely scalding rats infliced by oxygen free radicals.

Alanine Transaminase↗
PubMed2001

[Malignant transformation of human bronchial epithelial cells induced by benzo(a)pyrene metabolite dihydroxyepoxy benzo pyrene].

The malignant transformation of human bronchial epithelial cell 16HBE induced by benzo (a) pyrene metabolite--dihydroxyepoxy benzo pyrene (BPDE) was studied. 16HBE cells were treated several times with BPDE at different concentrations in vitro. The identification on the malignancy of transformed 16HBE cells was investigated. The transformed cells in foci were proliferated rapidly, exhibited in extensive random orientation and crossed over. The transformed cells could grow on soft agar. The colony forming frequency of each BPDE group on soft agar was significantly higher than that of control group and showed dose-reaction relations with the concentrations of BPDE. The transformed cells could grow into tumors in nude mice. The tumor was squamose carcinoma confirmed by histopathological examination. The culture system in this study provided a potential tool for studying the molecular mechanism of carcinogenesis of human bronchial epithelial cells induced by BPDE.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed2001

[Effects of exogenous adenosine 5'-monophosphate on proliferation and apoptosis of small intestinal epithelial cells].

The effect of exogenous adenosine 5'-monophosphate (AMP) on proliferation and apoptosis of a normal rat small intestinal epithelial cell line, IEC-6, was investigated. Proliferation of IEC-6 was measured by MTT. Cell cycle and apoptosis was determined by flow cytometry. Expression of Bax was detected by immunohistochemistry. The results showed that AMP remarkably inhibited the proliferation of IEC-6 in a dose- and time-dependent way. AMP also significantly changed the distribution of cell cycle, arrested cells in S phase and enhanced apoptosis by inducing Bax expression.

Adenosine Monophosphate↗
PubMed2001

[Observation on the effect of GM-CSF and alpha-INF joint treatment on chronic hepatitis B].

OBJECTIVE: To observe the effect of GM-CSF and alpha-INF joint treatment on chronic hepatitis B. METHODS: GM-CSF treatment combined with alpha-INF was set up as experimental group and alpha-INF alone as the control. At the same time, we counted the blood leukocytes, monocytes and granulocytes of the patients. RESULTS: The short-term and long-term effective rates of the experimental group were 61% (11/18) and 67% (12/18) respectively, while those of the control group were 44% (8/18) and 33% (6/18) respectively. The leukocyte, monocyte and granulocyte counting in blood of patients treated with GM-CSF and alpha-INF increased significantly. CONCLUSION: GM-CSF and alpha-INF joint treatment is effective for chronic hepatitis B. The mechanism may be related with the increasing number of monocytes in blood, hence to improve the antigen delivering ability.

Adolescent↗
PubMed2001

[The effect of leukotriene antagonist on the parameters of dose-response curve obtained after methacholine challenge test].

OBJECTIVE: To investigate the effect of leukotriene antagonist (zafirlucast) on the parameters of dose-response curve (DRC) obtained after methacholine challenge test. METHODS: A therapy trial was conducted with the use of zafirlucast in 20 cases of cough variant asthma (CVA) and 20 cases of asthma. Placebo was used in 4 cases of CVA and 10 cases of asthma for comparison with the two therapy groups respectively. Before and after the zafirlucast treatment a series of parameters of DRC were obtained after the methacholine challenge test and were calculated. These included the response threshold (PC35sGaw), the dose-response slope (DRS), the ratio of the area under the curve to the logarithm of the maximal concentration (AUC/1 g[Cmax]), and the maximal response. RESULTS: Zafirlucast significantly increased the PC35sGaw in the CVA and asthma groups. It conspicuously decreased all the parameters of DRS and AUC/1 g[Cmax] except for maximal response in the cases of CVA, and it had no significant effects on all the parameters of DRS and AUC/1 g[Cmax] except for PC35sGaw in the cases of asthma. CONCLUSION: Short-term use of Zafirlucast in asthmatic patients could improve the parameters of dose-response curve obtained after the methacholine challenge test.

Adult↗
PubMed2001

[Measurement of the parameters of dose-response curve obtained after the methacholine challenge test].

OBJECTIVE: To investigate the clinical value in the measurement of parameters of the dose-response curve (DRC) obtained after the methacholine challenge test. METHODS: Twenty-seven cases of cough variant asthma (CVA), 29 of mild asthma, 19 of moderate asthma, and 15 healthy volunteers underwent the methacholine challenge test. The dose-response curves were constructed. The following parameters were calculated: position (PC35sGaw), dose-response curve (DRS), ratio of the area under the curve to the logarithm of the maximal concentration (AUC/lg[Cmax]) and maximal response. RESULTS: A plateau appeared in 11 cases among the healthy subjects, while a plateau appeared only in 2 cases of CVA and 2 of asthma. There were no significant differences among the asthmatic groups in the measurements of PC35sGaw and AUC/lg[Cmax] (geometric mean PC35sGaw: mild asthmatics = 0.369, moderate asthmatics = 0.251, cough variant asthmatics = 0.547), AUC/lg[Cmax] was significantly greater in the asthmatic groups than in the normal group [AUC/lg [Cmax](mean +/- s): mild asthmatics = 24.7 +/- 4.7, moderate asthmatics = 26.6 +/- 4.3, cough variant asthmatics = 25.6 +/- 3.7, normal subjects = 15.5 +/- 4.3, P < 0.01]. DRS of moderate asthmatics was significantly greater as compared with cough variant asthmatics (geometric mean DRS: mild asthmatics = 30.761, moderate asthma-tics = 59.020, cough variant asthmatics = 19.231, P < 0.05), but there was no difference between the other groups. PC35sGaw was negatively correlated with DRS (r = 0.866, P < 0.001) and with AUC/lg[Cmax] (r = 0.502, P < 0.001). CONCLUSION: Four parameters of DRC obtained after the methacholine challenge represent airway sensitivity and reactivity respectively. The parameters of DRC of asthmatic patients are different from those of normal subjects. The sensitivity is related to the reactivity, but they are not completely parallel with each other.

Adult↗
PubMed2001

[Effects of mechanical stretch on collagen type I and total protein synthesis of human periodontal ligament fibroblasts].

OBJECTIVE: The aim of this study is to investigate the effects of mechanical stretch on type I collagen and total protein synthesis of human periodontal ligament fibroblasts (PDLFs). METHODS: Enzyme link immunosorbent assay (ELISA) and Coomassie brilliant blue stain method were used to examine the anabolism of PDLFs growing on the flexible culture plates subjected to mechanical stretch. The five loading devices of PDLFs were designed and the stain varied from 1% to 8%. RESULTS: Mechanical stretch had no effect on type I collagen synthesis. However, in the range of 1% to 8% of stretch, the protein synthesis was reduced. The mechanical stretching of 2% strain affected the protein synthesis most obviously. CONCLUSION: Mechanical stretch can modify the composition of extracellular matrix of PDLFs.

Cells, Cultured↗
PubMed2001

[A survey of oral health status of the elderly individuals in Chengdu of China].

OBJECTIVE: The aim of this survey is to investigate the oral health status of the oldsters over 65-year-old in Chengdu of China. METHODS: The oral health status, including oral hygiene, caries, periodontal diseases and the tooth loss of 468 elderly individuals over 65 years old were surveyed and analyzed. RESULTS: It was found that all these older individuals brushed their teeth everyday, but most of them had tooth decay, gingivitis and periodontitis. About 7.47% of them were edentulous, and 2.56% of them were half edentulous. The masticatory ability of most of them declined and the chewing ability of them was low. CONCLUSION: The oral health status of these elderly individuals in Chengdu is poor. It is therefore necessary to improve the health status of this population.

Aged↗
PubMed2001

[The effects of MMPs and TIMPs on the metastasis of oral squamous cell carcinoma to neck lymph nodes].

OBJECTIVE: This study is aim at investigating the relationship between the expression and activity of MMP-2,9, TIMP-1,2 and the metastasis of oral squamous cell carcinoma to neck lymph node. METHODS: The expression of MMP-2,9, TIMP-1,2 in 30 oral squamous cell carcinoma, two oral squamous cell carcinoma cell lines GNM and TSCCa was detected by in situ hybridization; Zomography was performed to determined the activity of MMP-2,9 in cancer tissue and conditioned medium of GNM and TSCCa; Ability of invasion of GNM and TSCCa was measured with in vitro invasion assays. RESULTS: Both tumor cells and stroma expressed both MMP-2,9 and TIMP-1,2; It was found that MMP-2,9, TIMP-1,2 had a higher expression in patients with neck lymph node metastasis than those without metastasis (P < 0.05), positive percentage of MMP-2,9 in GNM was higher than that in TSCCa; The MMP-2,9 in node-positive patients was more active than in node-negative ones (P < 0.05); GNM had more active MMP-2, 9 and higher invasive potential than TSCCa. CONCLUSION: MMP-2,9 may play an important role in metastasis of oral squamous cell carcinoma; Elevation of TIMP-1,2 is likely to be the result of interaction of tumor and stroma.

Adult↗