Search PubMed⌕ Search

Biomedical subjects

L Zhou

Publications and source records attributed to L Zhou.

At least 343 records · Page 19Linked to original sources
PubMed1998

[Studies on effects of cytokine released from alveolar macrophage induced by mineral dust on lung fibroblast].

OBJECTIVE: To understand the role of cytokine released from alveolar macrophage (AM) in lung fibrosis caused by mineral dust. METHODS: Rabbit's AM obtained by lavage was cultured with mineral dust in vitro. Activities of tumor necrosis factor (TNF) and interleukin 6 (IL-6) in its supernatant were determined with isotope labelling method and MTT colorimetry, respectively. Human fetal lung fibroblast WI-138 was cultured with this supernatant. Proliferation of fibroblast and synthesis of collagen were examined by 3H-thymidine (3H-TdR) and 14C-proline (14C-Pro) incorporation and its total hydroxyproline (HOP) level was analyzed by chloramine-T method. RESULTS: Proliferation of lung fibroblast and synthesis of collagen could be enhanced by the supernatant containing AM induced by quartz, asbestos and uranium mineral dust, with 3H-TdR incorporated counts per minute (cpm) of 6,584, 3,848 and 6,893 in the group of 100 micrograms 3H-TdR and 14C-Pro incorporated 27,952, 13,416 and 18,538 in the group of 200 micrograms respectively, which were significantly higher than those in the control group. Total HOP levels in the culture media for lung fibroblast enhanced by AM supernatant were 22.41, 24.00 and 21.39 micrograms/ml, respectively, and was significantly higher than that in the control group (12.91 micrograms/ml). Release of TNF and IL-6 could be stimulated by mineral dust, such as quartz, asbestos and uranium mineral dust, and their activities were significantly higher than those in the control group, with those of 1,396, 1,198 and 852 U/ml in TNF group and 1,336, 1511 and 1,335 U/ml in IL-6 group, respectively. Proliferation of lung fibroblast and synthesis of collagen could be inhibited by antibody against TNF and interferon-r (gamma), and the effect of the latter was weaker than that of the former on inhibition of fibroblast proliferation and the effect on collagen synthesis was just in the opposite direction. CONCLUSION: Lung fibrosis caused by mineral dust correlated with abnormal expression of TNF and IL-6. Antibody against TNF and gamma interferon could antagonize the effect of NTF and IL-6.

Animals↗
PubMed1998

[Dynamic analysis of incidence of silicosis in uranium miners].

OBJECTIVE: To understand the laws and characteristics of incidence of silicosis and to evaluate the effectiveness of prevention and treatment measures for it in uranium miners. METHODS: An epidemiological study was carried out in three uranium mines and two geological prospecting teams for uranium mines. RESULTS: Exposure to dust in all patients with silicosis initiated in 1950s to 1960s. Dust concentration and detection rate of silicosis have been decreasing, the length of employment in uranium mines and age at occurrence of the disease, interval between lower and upper stages of the disease, its duration and age at their death all have showed an increasing trend since the founding of the mines and geological prospecting teams more than thirty years ago. Those with delayed occurrence of the disease accounting for 20.31% of the total cases. The length of employment in the cases exposed to uranium dust averaged 7.47 years, and the age at occurrence averaged 36.74 years, less than in those exposed to mixed non-uranium dust. CONCLUSION: Effectiveness of comprehensive prevention and treatment measures for silicosis in uranium mines is significant. The average length of employment and age of the occurrence of the silicosis in those exposed only to uranium dust showed and younger.

Adult↗
PubMed1998

[Experimental study of the architecture of skin following tension traction and wound closure].

The experiment performed on domestic pig, was designed to investigate the architecture of the stretching skin and the effect of tension traction on the wound closure. An 7 cm x 3.5 cm was drawn at a standard position. Drawing horizontal and vertical lines on the traction area, points of 1 cm apart were tattooed on the lines. A traction force measuring device was used to draw the wound edges together. Measurements of the distances between the points were made. An 7 cm x 10 cm wound was made on identical sites of each hind leg. In the experiment the traction tension was applied on the edges of wound immediately after the wound debridement. The results showed the stretched distance in the two areas was 5-7 times the width of the wound. The gain of skin from traction was 61-89 percent in the width of the wound. The wounds from traction five days could be closed 5 days after traction. It was concluded that the skin which could be used for traction was abundant. Wound closure with the skin traction technique had many advantages, such as rapid decreasing the size of wound and early closing of wound.

Animals↗
PubMed1998

[Effect of mifepristone on the expression of progesterone receptor messenger RNA and protein in uterine leiomyomata].

OBJECTIVE: To determine the expression of progesterone receptor (PR) mRNA and PR protein levels in the myometrium and leiomyomata from untreated and mifepristone pretreated women with leiomyoma and to examine the mechanism of mifepristone treatment on uterine leiomyomata. METHODS: Expression of PR mRNA and PR protein were determined by Northern blot and HAP of single-dose saturated analysis in myometrium and leiomyomata (center and marginal area) from 27 untreated and 6 mifepristone pretreated women with leiomyomata. RESULTS: PR mRNA abundance and PR protein levels in both myomatous center and marginal area were significantly greater than those in corporal myometrium (P < 0.01) in both follicular and luteal phases, but similar between myomatous center and marginal area (P > 0.05). 6 cases pretreated with mifepristone 25 mg/day for 3 months were operated, all but one patient displayed a decrease in leiomyomata volume. PR mRNA abundance in both myometruim and leiomyomata (center and marginal area) was significantly decreased in 4 patients continuing mifepristone treatment before the operation but not in the other 2 patients stopping RU486 1 month before operation. PR protein levels in these tissues showed significant decrease in all 6 cases. CONCLUSION: There are overexpression of PRmRNA and PR protein in leiomyomata. One of the mechanism of mifepristone action on decreasing leiomyomata volume may be related to suppression on expression of PR gene. It seems that suppression on transcription of PR gene is reversible, but on translation of PR gene may maintain in a relatively longer period.

Adult↗
PubMed1998

[Study on the beta-lactamases of the Escherichia coli HX88108 resistant to ceforperazon].

E. coli HX88108 was isolated from a patient and found to produce plasmid-encode beta-lactamases with conferring highly resistance to ceforperazone(CPZ). The beta-lactamases of the E. coli HX88108 and transformants pFC, pFT1, pFT2 and pFT3 were studied. The beta-lactamases stability test among 11 beta-lactam antibiotics showed that beta-lactamases from E. coli HX88108. pFC, pFT1, readily hydrolyzed penicillins, the first, second-generation cephalosporins and CPZ. beta-lactamases of pFT2 and pFT3 hydrolyzed penicillins more strongly than cephalosporins. On the other hand, experiments of inhibiting enzyme were carried out. The results indicated that beta-lactamases of HX88108, pTF1, pFT2 and pFT3 were inhibited by clavulanic acid(CA) and sulbactam (SBT). Enzyme of pFC was inhibited poorly by CA and SBT. Through isoelectric focusing technique, the PIs were as follows: HX88108 contained three beta-lactamases, of which the PIs were 5.25, 5.3 and 5.6 respectively; the PIs of beta-lactamases from pFT2, pFT3, were 5.3 and 5.6. pFC and pFT1 were different plasmids encoded beta-lactamases with the same PI 5.25. The results indicate that the beta-lactamases of E. coli HX88108 may be a new member in TEM farmily.

Anti-Bacterial Agents↗
PubMed1998

[Expression of P62c-myc protein in breast cancer and its clinical significance].

The objective of this study was to determine the clinical significance of P62c-myc protein expression in breast cancer. P62c-myc protein was detected in 107 patients with breast cancer by immunohistochemical techniques (LSAB). The results showed that the positive rate of P62c-myc protein expression was 63.55% (68/107). The overexpression of P62c-myc protein related negatively with survival. 94.00% of the cases with overexpression of P62c-myc protein survived < or = 5 years, 65.00% survived > 5 years-< 10 years, and 21.62% survived > or = 10 years. There were significant associations of P62c-myc expression with advance clinical stage, high histological grade, and positive axillary node status in breast cancers. All of these findings suggested that overexpression of P62c-myc might be an important prognostic factor, and the detection of P62c-myc protein might be arranged as a regular pathological examination in the cases of breast cancer.

Adolescent↗
PubMed1998

[Randomized controlled study of leucomax (recombinant human granulocyte-macrophage colony stimulating factor, rhGM-CSF) in the treatment of cancer chemotherapy-induced leucopenia].

OBJECTIVE: To evaluate leucomax (rhGM-CSF) in prevention and treatment of leucopenia and neutropenia induced by chemotherapy in cancer patients. METHODS: A multicenter, randomized, matched and cross-over clinical trial of the effect of leucomax on leucopenia and neutropenia induced by combination chemotherapy in cancer patients was conducted. Fifty seven enrolled patients were randomized into AB group and BA group. Each patient received two cycles of treatment. In group AB, combination chemotherapy and leucomax were used in the first cycle and combination chemotherapy alone was used in the second cycle, while vice versa in group BA. In 2 patients, the study was stopped due to leucomax adverse reactions. Fifty five patients were eligible for analysis of clinical efficacy. RESULTS: Leucomax significantly increased the number of total white blood cell count and absolute neutrophil count at the nadir, decreased the incidence of leucopenia and neutropenia and shortened the time period of leucopenia and neutropenia induced by chemotherapy. Leucomax also resulted in quicker recovery of leucopenia and neutropenia. Leucomax ensured the scheduled chemotherapy. The main adverse reactions with mild to moderate fever, pain at the injection site, bone pain, myalgia, asthenia and skin rash were generally tolerable. CONCLUSION: Leucomax is a valuable adjunct in cancer chemotherapy.

Adult↗
PubMed1998

[A randomized trial of Zudan in the prophylaxis of nausea and vomiting induced by cisplatin].

OBJECTIVE: To study the anti-emetic effect of Zudan on high-dose cisplatin and its toxicity. METHODS: A randomized, crossover assay was used in thirty patients who received cisplatin chemotherapy to compare the efficacy and the toxicity of identical dose of Zudan and Zofran. RESULTS: The response rate of acute vomiting induced by cisplatin was 70.0% in patients receiving Zudan and 63.3% in those receiving Zofran. Complete response rate was 56.7% in Zudan arm and 53.3% in Zofran arm. The two arms were not remarkably different in response rates or adverse reactions. CONCLUSION: Zudan is safe and effective in the control of vomiting induced by cisplatin.

Adolescent↗
PubMed1998

[The relationship between LPS-induced apoptosis in hepatocyte, Kupffer cell and hepatocytic damage].

OBJECTIVE: To study the role of tumor necrosis factor (TNF alpha) in the mechanisms of liver injury and the relationship between LPS-induced apoptosis in hepatocyte (HC), kupffer cell (KC), and hepatic damage. METHODS: In vitro, kupffer cells (1 x 10/ml) were stimulated with different concentrations of endotoxin (1-10 micrograms/ml) for 1-24 hr; the kupffer cells, which had been cultured with endotoxin for 24 hr, were isolated to coculture with hepatocytes (1:1) for 1-24 hr. Two kinds of cells of apoptosis and the block effect of TNF alpha antibody were detected by cell death ELISA, and the supernatant was performed to determine the levels of alanine aminotransferase (ALT), lactate dehydrogenase (LDH) at different time points. RESULTS: Following stimulation with LPS, the number of positive apoptotic KC increased in a concentration and time (3 h-24 h) dependent manner. In contrast, coincubation of HC with LPS-stimulated KC resulted in a marked increase in positive apoptotic hepatocyte when LPS concentration was greater than 1 microgram/ml. TNF alpha antibody blocked apoptosis in both KC and HC. Only when the LPS concentration was higher than 1 microgram/ml and cultured for 6 hr, the release of liver enzymes (ALT, LDH), responsible for hepacyte damage, rose significantly, but the process was behind of apoptosis, and TNF alpha antibody couldn't block it. CONCLUSION: TNF alpha mediates LPS-induced apoptosis in KC and HC, and the apoptosis precedes cellular damage. Massive apoptosis of KC may lead to the decrease of clearance of LPS, thereby exacerbating septic shock, hepatocyte damage and apoptosis.

Apoptosis↗
PubMed1998

U-74389G suppresses lipid peroxidation and apoptosis following focal cerebral ischemia and reperfusion in rats.

OBJECTIVE: To study the antioxidant and antiapoptotic effects of U-74389G on ischemic brain in rats. METHODS: Right focal cerebral ischemia and reperfusion was induced by suturing in 103 male SD rats weighing 280-310 g. To determine LPO in the cortex and striatum, we randomly divided 78 rats into 5 groups: group 1, sham-operative group (6 rats); group 2, control (18); group 3, U-74389G administration before ischemia (18); group 4, U-74389G administration before reperfusion; group 5, CS-4 vehicle as negative control. Groups 2-5 were further divided into 3 subgroups according to the duration of reperfusion. Another 25 rats were similarly grouped (5) to detect apoptosis with TUNEL stain. RESULTS: The concentrations of MDA in groups 3 and 4 were reduced and the activities of SOD and concentrations of GSH were partially restored as compared with the control group. These effects were more significant in group 3 than in group 4. Otherwise, CS-4 can not provide protective effects. The number of apoptotic cells in groups 3 (P < 0.01) and 4 (P < 0.05) was significantly reduced as compared with the control group. CONCLUSIONS: U-74389G has antioxidant and antiapoptotic effects on ischemic brain in rats. The administration of U-74389G before the onset of ischemia was more useful than that before the onset of reperfusion.

Animals↗
PubMed1998

Extended frontotemporal epidural approach to cavernous sinus: surgical anatomy and technique.

OBJECTIVE: To investigate the surgical technique of trans-frontotemporal extended epidural approach to the cavernous sinus. METHODS: A microsurgical study on the exposure and dissection of the cavernous sinus and its surrounding structures on cadavers was performed via an extended epidural approach with frontotemporal skull-base craniectomy. RESULTS: The extended epidural approach offered an appropriate exposure of the cavernous sinus with minimal brain retraction and nerve damage. CONCLUSIONS: The extended frontotemporal epidural surgical approach is superior to the routine intradural or combined epi- and intradural approaches. It is suitable for most of the cavernous sinus surgeries.

Brain Neoplasms↗
PubMed1998

[RBC-CR1 genotype polymorphism and RBC immune function in childhood ITP].

OBJECTIVE: To investigate the RBC immune functions in childhood idiopathic thrombocytopenic purpura (ITP). METHODS: RBC-CR1 polymorphism genotype, RBC immune function and its regulator function were detected in 22 ITP, 30 allergic purpura (AP) and 50 normal children by PCR and Guo Feng's method. RESULTS: 1. There were 18 cases of high expression (82%) and 4 of medium expression (18%) of RBC-CR1 genotypes in the ITP cases. The rate of the medium expression genotype was significantly higher in ITP than that in AP and normal children (P < 0.01). 2. The rates of RBC-C3bRR and RBC-C3bRFER were much lower (P < 0.01), and the rates of RBC-ICR and RBC-C3bRFIR were significantly higher in ITP than those in normal children (P < 0.01). 3. RBC-CR1 genotypes in ITP were correlated negatively with RBC-C3bRR and RBC-C3bRFER (P < 0.05), but positively with RBC-ICR and RBC-C3bRFIR (P < 0.05). CONCLUSION: RBC immune participated in the pathogenesis of ITP.

Child↗
PubMed1998

[Regulatory role of 5-hydroxytryptamine and motilin in migrating motor complex of small bowel in dogs].

Migrating motor complex (MMC) was recorded by chronically implanted strain gauge transducers on the serosa of small bowel in conscious dogs. Two silastic catheters for injecting drugs and taking blood samples were put respectively in a vena jugularis externa and in a jejunal artery which perfused a 10-15 cm intestinal segment. The present study was undertaken to observe the effect of drugs administered intravenously and intraarterially on MMC and alterations of plasma 5-hydroxytryptamine (5-HT) and motilin in different phases of MMC. The results showed: (1) Levels of plasma 5-HT and motilin showed cyclical fluctuations in different phases of MMC, and 5-HT reached peak before peak of motilin. Plasma 5-HT level reached a peak [(41.2 +/- 1.3) ng/ml] in the later period of phase II, which increased significantly as compared with phase I [(22.4 +/- 1.1) ng/ml] (P < 0.01), but plasma motilin level had a peak [(580.0 +/- 30.2) pg/ml] in phase III of MMC, which was higher than that in phase I [(140.0 +/- 21.0) pg/ml] (P < 0.01). (2) Intravenous motilin and intraarterial 5-HT and motilin could induce phase III contraction in the canine proximal small bowel and in the perfused segment respectively. Amplitude of contractions caused by motilin was higher than that by 5-HT in the perfused segment. (3) 5-HT receptor antagonist, motilin antiserum, 5,6-dihydroxytryptamine and tetrodotoxin perfused intra-arterially inhibited expression of MMC in the perfused segment and its caudal propagation. We conclude that plasma 5-HT and motilin may be dominant factors which initiate MMC of canine small bowel, and 5-HT peak appears before peak of motilin. 5-HT neurons and motilin neurons in enteric nervous system may play an important role in controlling MMC of canine small bowel.

Animals↗
PubMed1998

[Long term results of Majer-Piquet's operation in the treatment of laryngeal carcinoma].

OBJECTIVE: To investigate the long term results of Majer-Piquet's operation in the treatment of glottic type of laryngeal carcinoma. METHODS: A series of 32 cases operated on between October 1990 and February 1995 were analysed, of whom 21 were T1N0M0, 3 were T1N1M0, 5 were T2N0M0 and 1 each for T2N1M0, T3N0M0, T3N1M0. RESULTS: In T1 cases, 2, 3 and 5 years survival rate were 95.8, 93.7 and 90.9% respectively, while in T2 cases, 2, 3 and 5 years survival rate were 100%, 83.3% and 60% respectively. Decannulation rate was 96.9%. All patients could finally take food by mouth without inspiration, and could speak as soon as decannulated. By modifing the operative technique, the cases operated on after 1994 got relatively better results in phonation. CONCLUSION: Majer-Piquet's operation not only is effective in the treatment of T1, T2 and some T3 glottic type of laryngeal carcinomas, but also can satisfactorily reserve laryngeal function and improve the quality of patient's life.

Adult↗
PubMed1998

[Development and applications of high performance membrane chromatography].

Development and applications of high performance membrane chromatography (HPMC) are introduced. Base membranes, membrane geometries and separations of biomolecules using high performance affinity membrane chromatography (HPAMC), high performance ion-exchange membrane chromatography (HPIEMC) and high performance hydrophobic interaction membrane chromatography (HPHIMC) are reviewed. Enantiomeric separation using HPMC are prospected. Seventy-six references are cited.

Chromatography, Affinity↗
PubMed1998

[Parameters of arterial occlusion during intracranial aneurysm surgery].

OBJECTIVE: To evaluate parameters, owing to temporary and/or permanent intraoperative arterial occlusion, could be related to the postoperative development of ischemic injury. METHOD: During 3-year period between October 1994 and March 1997, 27 patients with intracranial aneurysm were operated on with the aid of temporary and/or permanent arterial occlusion. Continuous intraoperative monitoring lCBF of the territories undergoing occlusion was carried out using LDF. Univariate analysis was used to study the relationship between the study variable and cerebral infarction. These variables included patient age, sexuality, aneurysm size, preoperative Hunt and Hess grades, LDF baseline value, LDF value following arterial occlusion and release of occlusion, the duration of arterial occlusion, the numbers of occlusive episodes, and the degree of arterial occlusion. Student's t-test was used for comparison of continuous variable such as age, and chi-square analysis was used to test the association of categorical variables. RESULT: The LDF value following arterial occlusion or residual lCBF, the duration of arterial occlusion, the numbers of occlusive episodes, and the occlusive degree were found to be significantly related to the postoperative development of ischemic injury. CONCLUSION: The residual lCBF and collateral circulation following arterial occlusion can be evaluated using LDF monitoring. When residual lCBF is more than 50 per cent of the baseline and the duration of arterial occlusion less than 20 minutes, temporary arterial occlusion is safe and does not develop postoperative ischemic injury.

Adolescent↗
PubMed1998

[Effect of ischemia-reperfusion on membrane structure and function in rat retina].

OBJECTIVE: To study the effect of ischemia-reperfusion on membrane structure and function in rat retina. METHODS: Thirty-two SD rats were randomly grouped into 4 groups. Group 1 served as the control group, group 2, 3 and 4 served as reperfusion 3 hours, 30 hours and 5 days respectively. The intraocular pressure (IOP) was raised to occlude retinal and choroidal blood vessels to form retinal ischemia; afterwards the IOP was lowered to normal to allow reperfusion. The animal was sacrificed after reperfusion. The colorimetric determination of phosphorus was used to investigate Na(+)-K(+)-ATPase activity of rat retina; the cellular membrane was labelled by fluorescence probe DPH to detect its fluidity which was measured by means of fluorescence spectrophotometer. RESULTS: Na(+)-K(+)-ATPase and membrane influidity were damaged at early stage. The longer the ischemia, the more serious was the reperfusion injury. CONCLUSIONS: The mechanism of the decrease of Na(+)-K(+)-ATPase activity is due to the production of substances involved in peroxidation and excitatory amino acid (EAA) which are produced during reperfusion. They can damage the Na(+)-K(+)-ATPase directly. Lipid peroxidation disrupts membrane integrity and causes decrease of membrane influidity. For these reasons, membrane stability is reduced and Na(+)-K(+)-ATPase protein function is changed.

Animals↗