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Biomedical subjects

Z Wang

Publications and source records attributed to Z Wang.

At least 757 records · Page 42Linked to original sources
PubMed2000

[Anatomical study and clinical applications of the tensor fascia lata myocutaneous flap].

OBJECTIVE: To explore the causes of blood circulation problems in 3 of 6 cases of pedicled tensor fascia lata myocutaneous flap transferring. METHODS: Anatomical study was performed on 16 cadavers (32 sides) after red emulsion injection. RESULTS: On 22 sides of 12 cadavers, the nutrient arteries lie in the muscle; on 2 sides of 2 cadavers, intramuscular nutrient arteries coexist with the big branches anterior to the muscle; on 4 sides of 3 cadavers, intramuscular nutrient arteries coexist with the big branches in the loose connective tissue deep to the muscle; on 4 sides of 3 cadavers, the nutrient arteries locate in the subcutaneous layer. According to the anatomical observations, much attention were paid to protect the vessels deep, superficial and anterior to the muscle during surgery, which resulted in successful clinical applications in 8 cases. CONCLUSIONS: The supplying arteries of the tensor fascia lata myocutaneous flap may exit not only intramuscularly, but also deep, superficial and anterior to the muscle. Special attention should be paid to them during operation.

Adolescent↗
PubMed2000

[Effect of acute hypobaric hypoxia on renal function and structure in rats].

OBJECTIVE: To observe renal damage due to acute hypobaric hypoxia. METHOD: Thirty-six male wistar rats were randomly divided into three groups A, B and C (n = 12 for each). Group A served as control, while groups B and C were exposed to 5000 m altitude for 30 min. Sample of serum and renal tissues were taken from group B rats 20 min and from group C rats 24 h after the exposure respectively. RESULT: Serum ureanitrogen (BUN) and creatinine (Crea) increased significantly in group B and C rats after exposure to hypoxia (P< 0.01). Cl- and alkaline phosphatase (AKP) in serum also increased (P < 0.05), but renal endothelin (ET) decreased significantly (P < 0.01). All changes in group C rats tended to recover to normal level, except Cl- which continued to increase. Dilation of renal vessels was found under optic-microscope, and pathological changes were found in mitochondra and epithelial cells. CONCLUSION: Acute hypobaric hypoxia might be harmful to renal function and structure.

Alkaline Phosphatase↗
PubMed2000

Chemical characterization and immunological activities of an acidic polysaccharide isolated from the seeds of Cuscuta chinensis Lam.

AIM: To study chemical characterization and immunological activities of an acidic polysaccharide, CHC-1, isolated and purified from the seeds of Cuscuta chinensis Lam. METHODS: Both chemical and spectral methods were used to investigate the chemical characterization of CHC-1. Effect of CHC-1 on the proliferation rates of T- and B-lymphocytes both in vivo and in vitro, and antibody production in vivo was measured at various concentrations of CHC-1. RESULTS: The molecular weight of CHC-1 was estimated to be more than 1.0 x 10(6). The analytical results of sugar components indicated that CHC-1 was composed of Rha, Ara, Gal, and GalA in a molar ratio of 0.8:1.0:1.5:0.3. Methylation analysis and 1H, 13C NMR further identified the linkages of the residues of CHC-1. CHC-1 0.1 g/L promoted remarkably the proliferation of T-cells and B-cells in vitro. CHC-1 25 mg/kg, 50 mg/kg caused an evident increase in spleen weight, lymphocyte proliferation, antibody production, etc. But its effect on IgG levels was not significant. CONCLUSION: CHC-1 is a highly branched heteropolysaccharide and possessed immune enhancement activities.

Animals↗
PubMed2000

[Application of competition index in assessing intraspecific and interspecific spatial relations between manchurian ash and dahurian larch].

The competition among trees within a stand includes aboveground and underground parts. How to determine the zone of competition influence is important for predicting tree growth. We divide the zone into two parts: one part is defined as inside radius, the distance from nearest competitors to subject tree, in which, the competition influence is the sum of both aboveground and underground; the another part is defined as outside radius, the distance of competitors to subject tree, where the competition influence comes mostly from underground. Thus, the competition index, based upon the divided two radii, could be decomposed into different components. We used the data of manchurian ash(MA) (Fraxinus mandshurica) and dahurian larch(DL) (Larix gmelini) from pure and mixed stands to analyze the competition influence of aboveground and underground in inside and of underground in outside radius. The results show that for MA in pure stand, the competition effect was 59.06% from inside radius, and 40.94% from outside radius. For DL in pure stand, the competition effects in both radii were 71.31% and 28.69%, respectively. There was a stronger competition influence in inside than in outside radius. Underground competitions were the important issues for both species in pure stands. In a mixed stand of MA and DL, there were two species in both radii, and the effects of competition came from intraspecific and interspecific competitors. For subject tree of MA, the effect of interspecific competition was 49.55%, and that of intraspecific was 50.45%. For subject tree of DL, the effects were 81.11% and 18.89%, respectively. DL displayed a stronger interspecific competition than MA in the zone of competition influence, and was a main effect of competition on MA. For subject tree of MA, the effect of competition from inside radius was 25.33%, which was the sum of competition influence from aboveground and underground, and about 74.67% was from outside radius. For subject tree of DL, both in inside and outside radii were 55.37% and 44.64%, respectively. Comparing with the information from both species and two radii, the root-root competition from underground was an important component. DL grew well, and could reduce the impact of intraspecific competition for MA when both species mixed in a stand.

Ecosystem↗
PubMed2000

[Individual tree growth-competition model in mixed plantation of manchurian ash and dahurian larch].

Based on distance-dependent competition models and neighborhood interference models, the competition index components and competition effect coefficients were used to quantify the spatial competition among trees in the mixed plantation of ash(Fraxinus mandshurica) and larch(Larix gmelini). Taking each component of competition index as independent variables and the yearly volume growth as dependent variable, the competition-growth model was established with good regression result. The study provided a new approach to deal with the further improvement of spatial competition models and the plant competition-growth relationship ecological study.

Ecosystem↗
PubMed2000

[Effect of different nitrogen forms on growth of Fraxinus mandshurica seedlings].

The effect of NO3(-)-N and NH4(+)-N and their different supply ratios on the growth of Fraxinus mandshurica seedlings was studied by sand culture in greenhouse. The highest seedling growth was obtained at a NH3(-)-N/NH4(+)-N ratio of 75/25 in nutrient solution. The growth of seedlings declined with the increasing ratio of NH4(+)-N to NO3(-)-N. Excessive NH4(+)-N inhibited root growth, and the root/shoot ratio of the seedlings significantly decreased as the NH4(+)-N/NO3(-)-N ratio was over 50%. Increasing NH4(+)-N in nutrient solution led to the decrease of net photosynthetic rate, the increase of phosphorus content in plant tissues, and the decrease of Zn and Fe contents. The pH value of cultural medium was affected markedly by nitrogen form, which was increased with increasing NO3(-)-N and decreased with increasing NH4(+)-N in nutrient solution. The pH value was up to 7.22 in the medium contained NO3(-)-N alone, while decreased to 4.20 only with NH4(+)-N.

Hydrogen-Ion Concentration↗
PubMed2000

[Utilization of insoluble phosphate by Larix gmelini seedlings under phosphorus starvation].

The utilization of insoluble phosphate by 2 years old larch(Larix gmelini) seedlings was studied in greenhouse. The seedlings were grown in sand and AlPO4 was supplied as a source of P. The results showed that larch seedlings could utilize some amount of AlPO4. Supplied with AlPO4 but not incubated with mycorrhizal-fungi, the seedlings could absorb 35.1% and 64.9% of the phosphorus uptake when supplied with soluble phosphate. The effects of various mycorrhizal-fungi on utilization of phosphate were different, i.e., the utilization rate of AlPO4 was higher when incubated with Suillus granulatus, but was similar to control when incubated with Suillus grevillei. The proportion of root/crown became higher under P-starvation, and larch seedlings could gain more P by enlarging their root growth.

Aluminum Compounds↗
PubMed2000

[Qingshishan watershed agro-ecology information system and its application with the support of Geographic Information System (GIS)].

Geographic Information System(GIS) is applied to establish Qingshishan Watershed Agro-Ecology Information System (QWAEIS), QWAEIS integrates spatial information such as land use, soil, water and topography with basic information such as population, climate and agricultural production. The watershed agro-ecology information was effectively analyzed and managed by QWAEIS, land suitable classes were evaluated by QWAEIS and the land evaluation result are given, QWAEIS also can support watershed planning with its spatial information.

Agriculture↗
PubMed2000

[N cycle of rubber-tea-chicken agro-forestry model in tropical area of China].

The N cycle of rubber-tea-chicken eco-agricultural model, a typical tropical agro-forestry system in Wenchang municipality of Hainan province, was studied with quantitative experiment and qualitative analysis, compared with rubber and rubeer-tea systems. The results showed that the N cycling rate, N output and soil surplus N of chicken garden were all the highest, being 43%; 196.5% kg.hm-2 and 237.6 kg.hm-2, respectively. The N output/input rate of chicken sub-system was 91%, and the transformation rate was very high. Compared with the other two systems, the chicken garden had a decreased external N input rate, and its internal cycling N was the highest, being 824.1 kg.hm-2. Rubber-tea-chicken agro-forestry system had a rational N cycling structure, and its N cycle was most active.

Animals↗
PubMed2000

[A wintering habitat model for red crown crane].

A mathematical model was established based on GIS and RS to simulate and predict the habitat distribution of red crown crane(Grus japonensis) in Yancheng Biosphere Reserve, Jiangsu Province, China. The model was tested through calculating the match coefficience of observed and predicted presence/absence data, which was 72.63%, showing that the model could be used to reflect the habitat distribution of red crown crane.

Animals↗
PubMed2000

[A method for designing buffer zone in Yancheng Biosphere Reserve: taking red crown crane as objective species].

Social, economic, ecological and geomorphic factors are needed to be considered when designing the buffer zone of natural reserve. In this paper, the Analytic Hierarchy Process(AHP) was applied to design the width of buffer zone. Under considerating the influences in different sections around the reserve, different widths of the buffer zone were designed, and a case study was carried out in Yancheng Biosphere Reserve. The results showed that the proposed method was reasonable and practicable in designing the buffer zone of nature reserve.

Animals↗
PubMed2000

[Effect of cadmium on soil animal community structure].

A indoor simulating test showed that there existed a close relationship between the community structure of soil animal and the concentration of soil Cd. When the concentration of soil Cd was high (99.48 mg.kg-1), the species, quantity, diversity index, homogeneous index, and abundance of soil animal were low. With the concentration going down, all indexes above increased gradually. When the concentration of soil Cd was 2.27 mg.kg-1, all the indexes were the same as control. The species and individuals of soil animal were negatively related with the natural logarithm of Cd concentration in soil.

Animal Population Groups↗
PubMed2000

[Molecular ecology of Cryptocarya chinensis populations in different communities].

The amplified fragment length polymorphism (AFLP) method was used to analyze two populations of Cryptocarya chinensis, the succession climax species in lower subtropical broadleaved forest. The across two communities of evergreen broadleaved forest and mixed coniferous-broadleaved forest. The analysis of molecular variance (AMOVA) indicated that the genetic variation was mostly due to the difference within individuals of the population (89.55%), with high significant genetic variation (10.45%) due to the different communities. The microenvironment of different communities and population biological characteristics resulted in the genetic divergence.

Analysis of Variance↗
PubMed2000

[Molecular markers and their application in plant population research].

This review surveys kinds of markers such as allozyme, AFLP, RAPD, SSR, RFLP and their application in molecular ecology of plant populations. The advantages and disadvantages of these molecular markers in plant population research are discussed based on the comparison of the methods and the experience in research work. It is considered emphatically that the adoption of the molecular markers is dependent on the various research purposes and different quality and quantity of the molecular information are acquired from various molecular marker methods.

DNA, Plant↗
PubMed2000

The circadian rhythm of blood pressure and the effect of salt intake in salt-sensitive subjects.

OBJECTIVE: To investigate the effect of salt intake on the circadian rhythm of blood pressure and the characteristics of ambulatory blood pressure (ABP) in salt-sensitive (SS) subjects. METHODS: Twenty-three normotensive subjects and forty-three patients with essential hypertension were included in this study. Salt sensitivity was determined with a chronic dietary salt loading test and an acute venous saline loading test, respectively. 24-hour ABP measurements were performed twice in normotensive subjects when they were on a high salt diet and when they had a low salt diet. Blood and urine samples were collected for measurement of plasma norepinephrine concentration (PNE), plasma renin activity (PRA), angiotensin II, aldosterone, erythrocyte sodium content and urinary sodium excretion. 24-hour ABP readings were also obtained in patients with essential hypertension when antihypertensive drugs were discontinued for at least 2 weeks. RESULTS: High salt intake attenuated the circadian rhythm of blood pressure in SS normotensive subjects, and the nocturnal decline in blood pressure was smaller in SS patients with essential hypertension than in salt-resistant (SR) patients. The level of PNE was higher and the suppression of PRA was smaller in SS subjects than in SR subjects when they had a high salt diet, and the urinary sodium excretion decreased and the erythrocyte sodium content increased significantly in SS subjects on high salt intake. CONCLUSIONS: High salt intake caused an abnormal circadian rhythm of blood pressure in SS subjects. The blunted nocturnal decline in blood pressure may be a characteristics of SS patients with essential hypertension.

Adult↗
PubMed2000

Hemostatic abnormalities associated with acute promyelocytic leukemia and corrective effects of all-trans-retinoic acid or arsenic trioxide treatment.

OBJECTIVE: To study in vivo effect of all-trans-retinoic acid (ATRA) or arsenic trioxide (As2O3) on the expression of tissue factor (TF) and the hemostatic disorders, a series of parameters were measured in bone marrow blasts and plasma from acute promyelocytic leukemia (APL) patients. METHODS: The plasma variables were measured by ELISA or chromogenic study. The TF transcription was assessed using reverse transcription-polymerase chain reaction technique (RT-PCR). RESULTS: The blast cell procoagulant activity (PCA), TF antigen of APL cell lysates, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As2O3 therapy. The plasma level of platelet alpha-granular membrane protein-140, soluble fibrinomonomer complex, thrombomodulin, tissue plasminogen activator and D-dimer significantly increased, fibrinogen, antigen level of protein C, plasminogen, alpha 2-plasminogen inhibitor and plasminogen activator inhibitor decreased at diagnosis, were restored to normal after complete remission but protein C activity and protein S remained elevated in ATRA group. CONCLUSIONS: There existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment. Both ATRA and As2O3 therapy down-regulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, inhibited coagulation activation, secondary hyperfibrinolysis and recorrected other hemostatic abnormalities, thus greatly improved the bleeding symptom in early stage of the treatment.

Adolescent↗
PubMed2000

Change of apoptotic status in the human colorectal adenoma-carcinoma sequences and its correlation with carcinogenesis and prognosis.

OBJECTIVE: To assess apoptotic status during the development of colorectal cancer and its prognostic value. METHODS: The apoptotic frequency of 168 fresh adenocarcinoma specimens and primary cultured cells at 2, 12, 24 and 48 hours (9 normal mucosa, 4 adenomas and 9 adenocarcinomas) were measured by flow cytometry (FCM). Apoptotic indices (AI) in situ for 25 adenomas and 77 adenocarcinomas were visualized by TdT-mediated dUTP nick end labeling (TUNEL), Ki-s5 labeling indices (KI), bcl-2, bax, waf1 and p53 were immunostained with ABC method. RESULTS: The culture-related apoptosis at 24-48 hours in vitro was obviously decreased in cultured tumor cells when compared with mucosa cells. Spontaneous apoptosis in situ occurred more frequently in tumor with aneuploid type at late stage. There was positive relationship between apoptosis and proliferative activity, determined by both TUNEL and FCM methods. The well-differentiated or early stage lesions with intensive bcl-2/bax expression were significantly more likely to have low AI. p53 accumulation and waf1 depression were mainly related to KI, whereas bax and waf1 overexpression led to a comparatively higher AI/KI ratio. bcl-2 and KI were found to be independent risk factors. CONCLUSIONS: The data suggest that the depressed susceptibility to inductive apoptosis may contribute to the initial phase of tumorigenesis, and spontaneous apoptosis in vivo may serve as a marker of tumor progression. The bcl-2 and KI may be valuable in predicting prognosis in colorectal cancer.

Adenocarcinoma↗