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Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 325 records · Page 18Linked to original sources

[Numerical dynamics of sediment bacteria in shrimp polycultural ecosystems].

The numerical dynamics of sediment bacteria was studied from May to September 1997, in the Shrimp Farm of Huanghai Fisheries Group Corporation with five experimental enclosures. It shows that the numbers of sediment bacteria ranged from 4.10 x 10(8) to 12.36 x 10(8) cells.g-1, averaged 8.09 x 10(8) +/- 2.17 x 10(8) cells.g-1, and increased gradually with increasing cultural time. The maximum was in 0-1 cm layer, and decreased obviously bellow 2-3 cm layer.

Animals↗

[Ecosystem management of settlement area in Xingshan County].

In the immigrant settlement area of Three-Gorges reservoir region in Xingshan County, Hubei Province, the ecological problems were the restoration of degraded ecosystem, rehabilitation of degraded crop land, and reconstruction of towns and villages. The key to the construction of the settlement area was reassigning the way of land use. The major aim of restoration of natural ecosystems should be to improve water conservation capacity of the land, because this area is located in the catchment of the Xiangxi River. The goals of management were determined as the coordinated development of both agricultural and natural forest ecosystems, the maintenance and increase of water conservation capacity of ecosystems, and the maintenance and extension of wildlife habitats. For the purpose of effective ecosystem management, the area was classified into four divisions of functional conservation region, functional rehabilitation, natural reserves and natural maintenance. The ecosystem management of the settlement area in Xingshan County was implemented in every land cell, using GIS and the typical grid-square survey method. The approach of multi-objects optimal spatial plan was developed in this paper, in which, special emphasis was put on the ecological, economic and social benefits in the construction of towns and villages. According to the scheme of management, the cover of forest in the settlement area, would increase by 30.19%, and water conservation capacity of the ecosystems would raise by 38.7%.

Agriculture↗

[Genetic variation of geographical provenance of Pinus massoniana--review and analysis].

Pinus massoniana is a significant tree species constituting the subtropical forests in China. Based on morphological, physio-ecological, chromosome, and molecular levels, the genetic variation of geographical provenance of P. massoniana and its distribution were reviewed, and the methodologies on genetic diversity and the genetic variation patterns of geographical provenance of P. massoniana were synthetically analyzed. The Key problems on molecular ecology of P. massoniana were discussed.

Ecology↗

[Beta-diversity of Stipa communities in Inner Mongolia Plateau].

The beta-diversity characteristics of four Stipa communities (S. baicalensis, S. grandis, S. krylovii and S. klemenzii) were studied using comparable plots methods. As a measurement of species turnover within communities, Whittacker's index(beta ws) was size-dependent, and reduced gradually with the increasing quadrat size. Under the same scale, beta ws indices of the communities were similar. Cody's index (beta c) was also affected by sampling size. beta c increased initially as quadrat size enlarged, then stabilized over the size of 0.5 m2 for S. baicalensis and S. grandis communities, and 2 m2 for S. krylovii and S. klemenzii communities. S. baicalensis community had the highest Cody index, while S. klemenzii community had the lowest one. In most cases, the within-community distance interval had a relatively high effect on Cody index; From S. baicalensis to S. klemenzii community, the functional group diversities of forbs, perennial bunch and rhizome grasses decreased greatly, the diversity of intermediate xerads reduced significantly, and the diversity of xerads increased firstly, and then declined for S. klemenzii community. The changes in species composition of four Stipa communities could give a reflection to the degrees of community replacement along ecological gradients, and Cody indices between the communities reduced gradually. The Morisita-Horn similarity coefficient between S. baicalensis and S. grandis community was significantly higher (0.72) than those between S. grandis and S. krylovii communities (0.55), and between S. krylovii and S. klemenzii communities(0.42).

China↗

[Effect of temperature on energy budget of Taiwanese red tilapia hybrid (Oreochromis niloticus x O. mossambicus)].

The energy budget of Taiwanese red tilapia hybrid (Oreochromis niloticus x O. massambicus) with a body weight of 25.33-26.23 g was measured at salinity 14 and at water temperature 22, 28 and 34 degrees C in July-August 1996. The results showed that its specific growth rate, conversion efficiency and maximum food consumption were significantly affected by temperature, and reached peaks of 1.79, 60.01% and 2.59% B.W.d-1 at 28 degrees C. The effect of temperature on the absorption efficiency was not significant, with an average absorption efficiency 64.58%. The effect of temperature on the proportions of food energy allocated to each component of the energy budget was significant. The ratio of growth energy was the highest(26.4%) at temperature 28 degrees C, and that of metabolism energy was 37.23%.

Absorption↗

Emodin on hepatic fibrosis in rats.

OBJECTIVE: To investigate effect of emodin on hepatic fibrosis in rats. METHODS: The rat hepatic fibrosis model was induced by the subcutaneous injection of 40% CCl4 (twice a week for 6 weeks) dissolved in olive oil. The emodin-treated rats were treated with low-dose, mediate-dose and high-dose emodin (20, 40 and 80 mg/kg body weight, once a day for 42 days) dissolved in 0.5% sodium carboxymethylcellulose (CMC), except receiving CCl4. Control group received only olive oil and 0.5% CMC. Liver functions were determined by standard procedure. Serum hyaluronic acid and laminin were determined by radioimmunoassay. Liver hydroxyprolines were determined. Histopathological changes were examined by optical microscopy. RESULTS: Compared with model group, the emodin-treated rats showed (1) liver functions were improved, alanine transaminase (ALT) and alkaline phosphatase (AKP) were obviously reduced, and total protein (TP) and albumin (ALB) were significantly increased; (2) serum hyaluronic acid and laminin were markedly reduced; (3) liver hydroxyproline was significantly decreased; (4) the degrees of fibrosis were reduced. The changes of parameters mentioned above were significant (P < 0.05 or P < 0.01). CONCLUSION: Emodin has effect on hepatic fibrosis in rats. The hepatoprotective of emodin may be one of mechanisms for liver fibrosis.

Animals↗

[The effect of plasma from women with preeclampsia on endothelial cells activators in vitro].

OBJECTIVE: To study the effect of plasma from women with preeclampsia on endothelial cell activators in vitro and determine whether factor(s) in the plasma of women with preeclampsia induces activation of vascular endothelial cells. METHODS: Twenty women with preeclampsia and 15 normal ones at late trimester of pregnancy were studied, from whom maternal venous blood samples were collected. Plasma 6-keto-PGF1 alpha, the end products of prostacyclin (PGI2) and TXB2, the end products of thromboxane A2(TXA2), were measured by radioimmunoassay. Plasma from women with preeclampsia or from normal women at late trimester was added to the bovine pulmonary microvessel endothelial cells in vitro. Twenty-four hours later, levels of 6-keto-PGF1 alpha produced by cultured endothelial cells were measured. RESULTS: The mean values of 6-keto-PGF1 alpha in matrnal venous plasma were (94.49 +/- 25.23) ng/L in preeclamptic group and (248.81 +/- 51.99) ng/L in normal pregnant group. Plasma TXB2 values were (104.61 +/- 13.12) ng/L in preeclamptic group and (66.26 +/- 38.80) ng/L in normal pregnant group. TXB2/6-keto-PGF1 alpha ratios were (1.11 +/- 0.03) in preeclamptic group and (0.28 +/- 0.02) in normal pregnant group. Maternal plasma values of 6-keto-PGF1 alpha were lower in peeclamptic group than those of normal pregnant group (P < 0.01). On the other hand, plasma TXB2 values were higher in preeclamptic group than in normal pregnant group (P < 0.01). TXB2/6-keto-PGF1 alpha ratios, however, were significantly different between the two groups (P < 0.01). The values of 6-keto-PGF1 alpha produced by cultured endothelial cells exposed to 2% plasma were (1,363.00 +/- 99.16) ng/L in preeclamptic group and (819.49 +/- 96.62) ng/L in normal pregnant group (P < 0.01). CONCLUSIONS: PGI2 and TXA2 may play an important role in preeclampsia. Plasma from women with preeclampsia could stimulate the production of prostacyclin in cultured endothelial cells in vitro.

6-Ketoprostaglandin F1 alpha↗

[Effect and mechanism of garlic juice and hydrogen peroxide on the degradation of lipopolysaccharide].

OBJECTIVE: To elucidate the effect and mechanism of garlic juice and hydrogen peroxide on the degradation of lipopolysaccharide (LPS). METHODS: Hot phenol-water method, phenol-chloroform-petroleum ether procedure, limulus lysate test, lowry's ash spetrographical examination and gas-liquid chromatography etc. were used in this study. RESULTS: The sequence of degradation effect was 30% hydrogen peroxide (H), the most powerful, followed by garlic juice (G), 1:1 diluted G and 3% H, their effects were dose dependent and G group was time dependent. The mechanism of H on LPS degradation was fractionization of phosphoryl in position 1 from lipid A, while that of G was complex, it could bound LPS molecule and influenced its effect besides LPS hydrolysis. CONCLUSION: The study may imply that the degradation position and mechanism on LPS are different and remain to be elucidated.

Biodegradation, Environmental↗

[Treatment of bacterial peritonitis with dachengqi decoction and rhubarb in mice].

OBJECTIVE: To observe the antiseptic effect of Dachengqi Decoction (DCQD) or rhubarb, one of the ingredients of DCQD in mice. METHODS: The model mice were established by peritoneal injection of Escherichia coli (10(8)/ml) or Proteus vulgaris (10(6)/ml) respectively. DCQD or rhubarb was given from 2 days before to 2 days after modelling for preventing and treating. RESULTS: The mortality and bacteremia occurrence of the treatment group were significantly lower than those of the control group (P < 0.05). Both DCQD and rhubarb showed protective effect on Escherichia. coli or Proteus vulgaris infection in mice. The cardiac blood smear and culture of survival mice in prevention plus treatment group and model group showed negative (bacteria) results but those of dead mice showed positive result. CONCLUSION: DCQD and rhubarb have excellent bactericidal effect.

Animals↗

[Effect of emodin on development of hepatic fibrosis in rats].

OBJECTIVE: To investigate the effect of emodin on the development of hepatic fibrosis in rats. METHODS: Forty percent of carbon tetrachloride (CCl4) dissolved in olive oil was injected subcutaneously to rats twice a week, for 6 weeks to produce hepatic fibrosis model, the rats of treated group were simultaneously injected with CCl4, treated with emodin in low, medium and high dose (20, 40 and 80 mg/kg body weight respectively) once a day for 42 days, which was dissolved in 0.5% sodium carboxymethylcellulose (CMC), while for rats of the control group, they only received CCl4 and CMC. Changes of serum hyaluronic acid, laminin and liver hydroxyproline were determined and histopathologic changes of liver was examined by optical microscopy and electronmicroscopy. RESULTS: Compared with the model group, in the emodin treated group: (1) Serum hyaluronic acid and laminin were markedly reduced (P < 0.05 or 0.01); (2) liver hydroxyproline was significantly decreased (P < 0.05 or 0.01); (3) degree of fibrosis was reduced (P < 0.05 or 0.01); (4) hepatocyte injury was ameliorated. CONCLUSION: Emodin has therapeutic effect on the development of hepatic fibrosis in rats. The effect might be related to slowing hepatocyte injury.

Animals↗

[Clinical study on ultra-early intravenous thrombolysis with high-dose urokinase in treatment of acute cerebral infarction].

OBJECTIVE: To determine the clinical curative effect and safety of ultra-early intravenous thrombolysis with high-dose urokinase in treatment of acute cerebral infarction. METHODS: Thirty-one patients with atherosclerotic cerebral infarction were treated with a single dose of 1.5 x 10(4) U/kg urokinase as intravenous thrombolytic therapy within 6 h after the onset. The decrease degree of nerve function defect integral, the cure rate, the effectual rate, and the total effective rate were observed 3 h and 21 days after thrombolysis, respectively, and the results were compared with those of conventional treatment. The infarct volume of patients treated with the two therapies were compared 21 days after treatment. RESULTS: The nerve function defect integral examined 3 h after thrombolysis (14.2 +/- 2.1) was markedly lower than that before thrombolysis (26.5 +/- 9.1). A remarkable difference (n = 31, t = 4.669, P < 0.05) was noticed between them. The cure rate and effectual rate reached 22.58% (7/31) and 67.74% (21/31), respectively. The decrease degree of nerve function defect integral, the cure rate, the effectual rate and the total effective rate evaluated 21 days after thrombolysis were all higher than those of conventional therapy group (from 26.5 +/- 9.1 to 8.8 +/- 2.8 vs from 26.4 +/- 8.1 to 16.3 +/- 4.1, t = 2.417; 51.61% vs 15. 38%, chi(2) = 5.037; 70.96% vs 42.30%, chi(2) = 4.765; 87.09% vs 65.38%, chi(2) = 3.886, respectively; all P < 0.05). The infarct volume was markedly smaller than that of the conventional therapy group (3.7 cm 3 +/- 3.0 cm(3) vs 5.3 cm(3) +/- 3.1 cm(3), t = 2.165, P < 0.05). CONCLUSION: Ultra-early intravenous thrombolysis with a single dose of 1.5x10(4) U/kg urokinase in the treatment of atherosclerotic cerebral infarction has a better clinical curative effect and less complication, and it can also have the infarct volume markedly reduced.

Cerebral Infarction↗

[Single cell analysis of H(2)O(2) mediated Fas mRNA expression and Ca(2+) influx in LO(2) cells].

OBJECTIVE: To investigate whether apoptotic injury is induced by Fas mRNA expression mediated by H(2)O(2) and concerned with intracellular Ca(2+) unbalance at a single cell level. METHODS: Fas mRNA expression in human hepatocyte (LO(2) cell) was analyzed by whole-cell patch-clamp combined with single cell reverse transcription polymerase chain reaction (RT-PCR). Cytosolic Ca(2+) concentration was measured with another whole-cell patch-clamp combined with single-cell microfluorescence [Ca(2+)] i measurement at the same time. The index of early phase apoptotic cells (Annexin-V(+) cells) measured with flow cytometry (FCM) and the hepatocytic morphological changes were observed by scanning electron microscopy. RESULTS: Fas mRNA of LO(2) cells cultured with H(2)O(2) (10 micromol/L) was expressed at 2 h. The single cell [Ca(2+)] i analyzed by another whole-cell patchclamp increased to 1 115 nmol/L +/- 227 nmol/L (P < 0.01, t = 13.37); at the same time, an elevated Ca(2+) wave was recorded. The index of Annexin-V(+) cells was as high as 16.18 +/- 0.65 (P < 0.01, t = 48.41), and the membrane surface protuberances were observed. CONCLUSIONS: The activation of Fas mRNA, as a major apoptotic factor mediated by H(2)O(2) in LO(2) cells, is probably associated with the imbalance of intracellular Ca(2+).

Apoptosis↗

[Separation of thoracopagus conjoined twins].

OBJECTIVE: To sam up the experience in diagnosis and separation of a thoracopagus conjoined twins. METHODS: Thoracopagus twin boys were admitted for evaluating possible separation and repair at age of 21 days. X-rays, CT, MRI, and ultrasound scan of torso showed separate and normal gastrointestinal and biliary tracts, little shared vasculature, but shared pericardium, diaphragm and liver parenchyma. The chest junctions were at the sternums and the most inferior two pairs of the ribs. One twin (twin A) had a protruding heart with VSD and ASD. RESULTS: The infants were separated successfully at age of 45 days. The chest defect of twin A was closed with aid of a polyester pericardial patch graft and a silicon supporter. Managing anesthesia met some difficulty in understanding of the anatomical and physiological consequences of the complex anomaly. They are had brain edema and multiple system organ failures after separation, and were cured under intensive care. They are alive and well 6 months after surgery. CONCLUSIONS: Careful preoperative evaluation proper anesthesia and surgical technique, and postoperative care are essential to the successful separation of the conjoined twins.

Anesthesia↗

[Total meso-rectal excision in low anterior resection with double stapling technique].

OBJECTIVE: To elucidate the value of total meso-rectal excision (TME) in low anterior resection with double stapling technique. METHODS: During January 1993 to October 1998, 306 cases of rectal lesions were treated by total meso-rectal excision in low anterior resection (LAR) with double stapling technique. Among the patients with rectal cancer, 235 (78.86%) were treated by low anterior resection and 97 (41.28%) by ultra-low anterior resection. RESULTS: No operative death was noted, and anastomotic leakage occurred in 9 (2.94%) patients. Ureter injury occurred in 2 (0.65%) patients. 32 (10.46%) patients suffered from anastomotic stenosis, 31 mm diameter of stapler for 27 (12.68%) patients and 33 mm diameter of stapler for 5 patients (5.38%). Local recurrence occurred in 20 (6.71%) patients: Dukes'B 4 (2.33%) patients, Dukes'C 9 (12.5%) patients, and Dukes'D 7 (53.85%) patients. CONCLUSIONS: Total meso-rectal excision can effectively reduce the local recurrence rate after LAR with double stapling technique. Since the recurrence is closely related to the stage of the disease, early detection, early diagnosis and early treatment are extremely important.

Adult↗

[Surgical treatment of anomalous origin of the left coronary artery from the pulmonary artery].

OBJECTIVE: To introduce the experience in surgical correction of anomalous origin of the left coronary artery from the pulmonary artery in 8 patients. METHODS: From 1991 August to 1999 March, 8 patients underwent surgery. Intrapulmonary tunnel procedure was performed in 7 patients, and coronary artery bypass grafting using the saphenous vein in 1. Mitral valve incompetence was repaired in 1 patient. ECG, echocardiographic and angiographic studies were made in all patients. 7 patients were followed up for 327 months (mean 46.8 +/- 10.7) months. RESULTS: No hospital deaths and later deaths occurred nor major complications during hospitalization. Because of suture of intrapulmonary tunnel loose, artery-pulmonary artery leakage 1 patient was reoperated on successfully. Follow-up showed cardiac function New York Heart Association function class I, mean LVMD (46.4 +/- 3.7) mm, vs mean (54.4 +/- 2.8) mm before the operation (P < 0.01), and mean EF (69.4 +/- 2.3)% vs mean 59.6% +/- 2.8% before the operation (P < 0.05). CONCLUSIONS: Anomalous origin of the left coronary artery from the pulmonary artery is a very rare congenital malformation. To correct the anomalous origin of the left coronary artery from the pulmonary artery is to reconstruct the normal two-coronary system and to treat the other associated diseases. Intrapulmonary tunnel operation is easy to perform satisfactorily.

Adolescent↗

[A serological investigation of Legionella infection in eight-species of poultry and domestic animals in Sichuan province].

OBJECTIVE: To understand the prevalence rates of Legionella infection in poultries and domestic animals in Sichuan province. METHODS: Serological investigation of antibodies against Legionella pneumophila serogroups 1 - 14 and Legionella micdadei was carried out, using microagglutination test (MAT) in eight species of poultries and domestic animals. RESULTS: Infections with multiple serogroups were identified. However, each species had its own major serogroup with positive rates of different serogroups ranging from 0.83% to 59.18%. Positive rates of the poultry and domestic animals were accounted for 7.73% and 4.25% respectively. CONCLUSION: It was suggested that poultries and domestic animals were widely infected with Legionella. It is important to carry out epidemiological surveillance in these domestic animals, poultries and environment for a better control program of this disease.

Animals↗

[Study on beta-adrenoceptors mechanism of cadmium immunotoxicity].

OBJECTIVE: To study if the beta-adrenoceptors mechanism plays important role in the immunotoxicity of cadmium. METHODS: The beta-adrenoceptor density, cellular cyclic adenosine 3',5' monophosphate (cAMP) levels, and DNA damage of rat spleen lymphocytes were studied. Beta-antagonist propranolol was used to block the beta-adrenoceptor. RESULTS: In the single Cd administration group: beta-adrenoceptor density of spleen lymphocytes in the middle and high Cd concentration groups was higher than that in the non-Cd treated control group (P < 0.05), the levels of cAMP increased with the increase of Cd doses, and the result of the high Cd group was higher than that of the control group (P < 0.05). The proliferation function of T lymphocytes was lower in each Cd group than that in the control group (P < 0.05). Single cell gel electrophoresis (SCGE) detected that DNA damage of spleen lymphocytes in each Cd group were more severe than the control (P < 0.05). Pretreated with Pro group: After blocked with propranolol, beta-adrenoceptor density increased in the Pro control group and the density in all Cd treated groups was higher than the control group (P < 0.05), but all Cd treated groups showed no statistical significance than the Pro control group (P > 0.05). The cAMP levels, MTT and the subsets of T lymphocytes showed no statistical significance among all the groups (P > 0.05). The results of SCGE showed that DNA damage was most severe only in the high Cd group than other groups (P < 0.05). CONCLUSION: The results suggest that the nerve-internal secretion system plays an important role in the immunotoxicity of cadmium, and the beta-adrenoceptor mechanism is important in the immunotoxic mechanism of cadmium.

Adrenergic beta-Antagonists↗