Biomedical subjects

B Li

Publications and source records attributed to B Li.

At least 163 records · Page 9Linked to original sources

PubMed2001

Allitridum mimics effect of ischemic preconditioning by activation of protein kinase C.

AIM: To investigate whether allitridum has the effect of pharmacological preconditioning and whether protein kinase C (PKC) plays a role in myocardial protection. METHODS: Thirty-four isolated rabbit hearts which subjected to 30 min of regional myocardial ischemia and 2 h reperfusion, were randomly divided into 5 groups: control group, ischemic preconditioning (PC) group, allitridum (A) group, polymyxin B (Poly B) group, allitridum + polymyxin B (A + Poly B) group. Infarct size was determined by triphenyltetrazolium staining. RESULTS: Pharmacological preconditioning in hearts with a 5 -min allitridum infusion 10 min before the prolonged regional ischemia resulted in significantly smaller infarcts (7 % +\- 6 % of risk area) than in control hearts (25 % +\- 7 %, P < 0.05). There is no significant difference in infarct size between (A+Poly B) group and control hearts (23 % +\- 5 % vs 25 % +\- 7 %, P > 0.05). CONCLUSION: These data indicate that allitridum can precondition rabbit ischemic myocardium and this protection can be effectively blocked by administration of Poly B, an inhibitor of PKC, implying that PKC has an important role in preconditioning.

Allyl Compounds↗

PubMed2001

[Histopathology and immunohistochemical expression of precursor lesions of cervical adenocarcinoma].

OBJECTIVE: To discuss the histopathology and immunohistochemical expression in precursor lesion of cervical adenocarcinoma-cervical intraepithelial glandular neoplasia (CIGN). METHODS: Histopathological examination and immunohistochemical study (SP method) were performed on 101 cases of CIGN. RESULTS: Criteria for histological grading of CIGN into three degrees, grade I to III, were proposed according to the hyperchromasia and the stratification of nuclei, number of mitoses and the amount of intracellular mucin. Adenocarcinoma in situ was classified as CIGN-III. 46.53% (47/101) CIGN showed a co-existence of CIN (SIL). 45 cases were CEA positive (44.55%) and 38 showed apical and luminal positivity. The positive rate of PCNA was 63.54% and was 100% in CIGN-III. The positive rate of ER was 81.48% (66/81). The expression of ER was often decreased or missing in certain cases. The positive rate of HPV 6/11 in CIGN I-III was 34.09% (30/88), 31.82% (28/88), and 3.41% (3/88), respectively. CONCLUSIONS: Histological grading of CIGN is important. Immunohistochemical staining for CEA, PCNA and ER may be helpful in diagnosis and differential diagnosis of CIGN.

Adenocarcinoma↗

PubMed2001

[Degradation of phenanthrene and pyrene in contaminated soil by immobilized Zoogloea sp. and Fusarium sp].

Immobilized with PVA, sodium alginate and activated carbon, both Zoogloea sp. and Fusarium sp. strains could degrade phenanthrene and pyrene efficiently. The optimal carrier was made of 100 rho.g-1 L PVA, 5 sodium alginate rho.g-1 L and 50 activated carbon rho.g-1 L. The degradation rates of phenanthrene and pyrene in 10 days were 87.48% and 75.34% by the immobilized bacterium, 37.04% and 20.85% higher than those by the free bacterium, and the rates in 15 days were 84.36% and 74.87% by the immobilized fungus, 5.35% and 11.23% higher than those by the free fungus.

Biodegradation, Environmental↗

PubMed2001

[Photobacterium phosphoreum assay on the toxicity of soil contaminated by heavy metals].

The toxicity of soil artificially contaminated by heavy metals was assessed with Photobacterium phosphoreum. The results showed that the duration of optimum balance was 24 hours, and that of optimum extraction was 2 hours. Two leaching methods were compared, and data showed that optimum leaching solvent was hydrocarbon chloride with a concentration of 0.1 mol.L-1 HCL. Dose-response curve indicated that the content of heavy metals was positively related with the toxicity of soil. The general detection limit given by EC50 of soil contaminated by single heavy metal were Cd 26.12 mg.kg-1, Cu 291.48 mg.kg-1, Zn 72.46 mg.kg-1 and Pb 2174.93 mg.kg-1. This study also indicated the toxicity of complex heavy metals pollution in soil was stronger than that of individual element. The research could provide a theoretic base for the remediation of soil contaminated by heavy metals.

Cadmium↗

PubMed2001

[Co-metabolic degradation of pyrene in soil].

High molecular weight Polycyclic Aromatic Hydrocarbons (PAHs) are always degraded by means of co-metabolism. This study compared the degradation process of pyrene as sole source of carbon and energy and co-metabolic degradation process of pyrene. The degradation rate of pyrene after 25 days in the first process was 57%, while the degradation rate of pyrene in the co-metabolic processes were about 80%. The half-life of pyrene in the co-metabolic process was shorter than those in the processes without co-metabolism. Salicylic acid, phthalic acid, sodium succinate could serve as co-metabolic substrate to enhance the degradation rate of pyrene, and sodium succinate has the best effect. There was co-metabolic relationship between pyrene and phenanthrene which was a kind of low molecular weight PAHs, phenanthrene accelerated the degradation of pyrene, while naphthalene didn't. The principle of the co-metabolism and the optimal material used as co-metabolic substrate were demonstrated in this paper.

Environmental Pollution↗

PubMed2001

[Catalytic reduction of NO by chars loaded with Ca and Fe].

The effects of calcium and iron impregnated on coal chars as catalysts in NO-char reaction were investigated. The NO-char reaction was studied in a quartz fixed bed reactor at atmospheric pressure. Temperature programmed reaction (TPR) and isothermal reaction were used to determine the catalytic activities of calcium and iron at various atmosphere environments. The results showed that the higher the temperatures of pretreatment, the lower the catalytic activity of calcium, while the pretreatment temperatures had little effect on the catalytic activity of iron. Both calcium and iron promoted the NO-char reaction, but the catalytic activity of the latter was higher than that of the former. NO reduction by CO was strongly promoted by Fe and Ca. The addition of O2 in the char-NO-Ca or char-NO-Fe system promoted the NO reduction significantly. Oxidation/reduction mechanisms were proposed for the NO reduction by char catalyzed by Ca and Fe.

Calcium↗

PubMed2001

[Human telomerase RNA (hTR) expression in lung cancer in the Gejiu and Xuanwei regions of Yunnan].

OBJECTIVE: To investigate the correlation between the expression of hTR in and the pathogenesis of lung cancer in Gejiu and Xuanwei regions of Yunnan province. METHODS: By use of in situ hybridization, the expression of hTR gene was observed in 81 cases of lung cancer tissues including 24 cases of Gejiu Tin miners (GTM), 36 cases of Xuanwei farmers (XF) and 21 cases of other regions. RESULTS: hTR was detected in 65.4% (53/81) of the lung cancer cases. The positive rate of hTR in GTM, XF and other regions was 66.7% (16/24), 58.3% (21/36) and 76.2% (16/21) respectively. Positive hTR expression was not found in normal bronchial and alveolar epithelia, but was found in highly proliferating type II alveolar epithelial cells adjacent to the carcinoma (12.3%, 10/81). No significant difference was observed with regard to the positive rate of hTR expression among three different regions. There was no statistically significant correlation between the expression of hTR, the patients' sex, age and the differentiation degree of the tumor, but the expression of hTR was correlated with histological type and lymph node metastasis (P < 0.05). CONCLUSION: The expression of hTR is a prevailing event in lung cancer and therefore can be used as an indicator of lung malignancy.

Adult↗

PubMed2001

[An investigation on morphology of experimental corneal neovascularization].

OBJECTIVE: To observe the morphologic character of the corneal neovascularization in experimental rabbits and also compare it with the morphology of that after irradiation with beta-rays. METHODS: A model of new blood vessels on the corneas of New Zealand rabbits was established with silver nitrate burning. The growth character of the neovascularization was compared between the irradiated and non-irradiated groups. The casting of the new blood vessels in different periods was made and the morphologic differences between the two groups were compared under a scanning electron microscope. RESULTS: The corneal new blood vessels occurred and continuously proliferated with the typical method of budding. The formation of buds was obviously inhibited and damaged after irradiation with &#61538 or &#61485 beta-rays, and the irradiated new branches were also atrophic and necrotic. CONCLUSIONS: Stopping the budding procedure of the corneal neovascularization may inhibit the formation and development of the corneal new blood vessels.

Animals↗

PubMed2001

[The relationship between maternal infection with human parvovirus B19 and fetal death and congenital malformation].

OBJECTIVE: To study the relationship between matanal infection with human parvovirus B19 and fetal death and congenital malformation. METHOD: B19-DNA was detected by Polymerase Chain Reaction (PCR) in blood samples from 335 pregnant women. The pregnant outcomes were followed. RESULTS: In 335 pregnant women, 67 cases were B19-DNA positive and 268 cases were B19-DNA regative. There were four fetal deaths and one anencephalus in B19-DNA positive group. There was no fetal deaths or congenital malformation in B19-DNA negative group. The difference is significant (P < 0.05). CONCLUSIONS: Maternal infection with human parvovirus B19 may contribute to fetal death and congenital malformation.

Congenital Abnormalities↗

PubMed2001

Gynecological procedures under gasless laparoscopy.

OBJECTIVE: To evaluate gasless laparoscopy in treating gynecological conditions. METHODS: With Kirschner wire lifting, transversely or longitudinally introduced into abdominal wall subcutaneously, we exposed the operative field and pelvic organs with routine operative instruments under epidural anesthesia. When a dense pelvic adhesion was confronted, we used the temporarily low-pressured pneumolaparoscopy to dissect it. RESULTS: All procedures were carried out without organ injury, hematoma, or other complications. The operative field can be clearly seen with this method. The mean time for appendagectomy was one hour and for laparoscopic assisted vaginal hysterectomy 80 minutes. CONCLUSION: Gasless laparoscopy avoids the complications which occur in the routine laparoscopy such as subcutaneous or mediastinal pneumatoma, hypercarbonemia, air embolism, cardiopulmonary dysfunction. Our lifting method is simple, convenient, time and money saving, as well as more flexible for treating gynecological conditions.

Adult↗

PubMed2001

[Study of mechano-sensitive K+ channel in cerebral microvascular endothelial cells from rats].

This study was conducted to gain an understanding of the electrophysiologic characteristics of cerebral microvascular endothelial cells. The stress response of the potassium ion channel in cerebral microvascular endothelial cells was explored. We developed a model of the opening shear stress effect device and used it for calculation of shear stress. The cultured cerebral microvascular endothelial cells from rats were seeded on glass slide of 1 cm x 1 cm. K+ ion channel current was recorded by Patch-Clamp amplifier of Axonpatch 200A type and whole cell Patch-Clamp technique. The inward rectifier potassium current of cerebral microvessel endothelial cells has been elicited by flow stimulus of 1.1 dynes/cm2 shear stress, and there is good relationship between the current and voltage changing. The various stress responses of the cerebral vascular endothelial cells are related to the stress sensitive potassium ion channels of cellular membrane.

Animals↗

PubMed2001

[The achievement of industrialized healthy aquatic breeding of hippocampus and its application prospects].

The artificial industrialized aquatic breeding of Hippocampus, which is a kind of Chinese medicinal marine material, has been achieved in the artificial aquatic breeding base of Hippocampus of Guangdong Richvast Group Company since 1983. This article reported part of the achievements of the large-scale artificial aquatic breeding experiments. The prospects for the research and application of Hippocampus as health foods and drugs were also analyzed.

Animals↗

PubMed2001

[Study on variation and interrelations of characteristics at ginseng germplasms].

The variation and interrelations of some characteristics of Panax ginseng germplasms(lines), which were five selfmating generations of some single plants were studied. Methods of multivariate analysis, such as correlation, regression, or clustering, and coefficient of variation were used. The results were of benefit to the breeding and standardized planting of Panax ginseng.

Genetic Variation↗

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

[Clinical and histopathologic analyses of after cataract in rabbit eyes having undergone three different cataract surgeries].

OBJECTIVE: To discuss the surgical method which can efficiently prevent the occurrence of after cataract. METHODS: Eighteen experimental rabbits were randomly divided into 3 groups. Group A was treated with phacoemulsification, group B with phacoemulsification combined with posterior continuous curvilinear capsulorhexis (PCCC) and Group C phacoemulsification combined with PCCC and anterior vitrectomy. Post-operatively, all the surgical eyes were checked with slit lamp microscope and ophthalmoscope. At the post-operative 3 months, histopathologic examinations were performed. RESULTS: There were no post-operative complications, such as retinal detachment, cystoid macular edema, etc. There were Elschnig's pearls and fibers in the peripheral area of the posterior capsule, and the amount was about the same in the 3 groups. There were Elschnig's pearls and fibers at the central area in group A. The fibrous membrane grew from the edge of the PCCC in group B. But in group C, the central area of the posterior capsule was clear, and there was no obvious pathological changes. CONCLUSION: Phacoemulsification combined with PCCC and anterior vitrectomy is a safe cataract surgical method which can effectively prevent the formation of after cataract.

Animals↗

PubMed2001

[Clinical pathological analysis of adenomatoid tumor in uterus and ovaries].

OBJECTIVE: To study the immunohistochemical feature and the differential diagnosis of adenomatoid tumors in uterus and ovaries. METHODS: Clinical pathological analysis and immunohistochemical studies were performed on 24 cases of adenomatoid tumors in the uterus and ovaries. RESULTS: Of the 24 cases, 21 cases were in the uterus, 2 cases in the ovaries and 1 cases in both the uterus and the ovary. Grossly, the mean diameter of the 22 uterus tumors was 2.2 cm, ranging from 0.2 - 5.5 cm. 14 (63.6%) were located in the subserosa or near by the subserosa of the uterine cornua. The other 8 tumors located in the myometrium. The cut surface presented a nodular pattern with grayish white or yellowish in color, partially cystic. 3 ovarian tumors became all cystic, without a clear-cut margin from the surroundings. Microscopically, the tumor consisted of various gland-like structure or luminal spaces lined with flat, cuboidal or low columnar cells, similar to blood vessels in structure. Among the tumor cells, there were scattered vesicular cells with large or small vacuoles, but no nuclear atypia and mitotic figures detected. Immunohistochemical staining showed the tumor cells positive for vimentin, AE(1)/AE(3) and calretinin, but negative for F VIII-Rag. S-100 and EMA were positive in 20 (83.3%) and 4 (16.7%) cases respectively. CONCLUSION: Adenomatoid tumor of the female genital tract is mesothelial in origin and uterus was considered as the most common site of occurance. Immunohistochemical phenotypes can be used as an important evidence for differential diagnosis. The biological behavior of adenomatoid tumor is benign and with a good prognosis.

Adenomatoid Tumor↗

PubMed2001

[Risk of leukemia among medical X-ray workers in China between 1950 and 1995].

OBJECTIVE: To explore the relationship between low dose radiation and leukemia and assess resultant risk of leukemia. METHODS: The leukemia incidences (1950 - 1995) in 27,011 medical diagnostic X-ray workers and in 25 782 non-radiation workers in hospital employed between 1950 and 1980 in China were compared by O/E system. RESULTS: The relative risk (RR) of leukemia in the medical X-ray workers was 2.17 (95% CI = 1.58 - 2.91, P < 0.01). The highest RR of leukemia was found in those who engaged in X-ray work before 1960 or at age under 20 years. CONCLUSION: There was a relationship between incidence of leukemia and X-ray radiation in X-ray workers and accumulation of radiation dosage and employment at younger age increased the risk of leukemia.

China↗

PubMed2001

[The expression of glucocorticoid receptor beta messenger RNA in peripheral white blood cells of hormone-resistant nephrotic syndrome patients].

OBJECTIVE: To study the molecular mechanism contributing to hormone resistance of nephrotic syndrome. METHODS: The specific hormone binding sites of receptor was determined by radioligand binding assay. Messenger RNA of receptor was determined by quantitative reverse transcription-polymerase chain reaction. RESULTS: No significant differences of specific hormone binding sites of peripheral white blood cells were observed among hormone-sensitive patients, hormone-resistant patients and healthy volunteers. However, in hormone-resistant patients, GR alpha/GR beta mRNA ratio decreased significantly as compared with that of hormone-sensitive patients and healthy volunteers. CONCLUSION: Results of the experiments indicated that the increased expression of GR beta, which leads to the decrease of the GR alpha/GR beta ratio, may be one of the mechanism responsible for hormone resistance in some nephrotic syndrome patients.

Binding Sites↗