Biomedical subjects

X Hao

Publications and source records attributed to X Hao.

At least 19 recordsLinked to original sources

PubMed2001

Model-based evaluation of two BNR processes--UCT and A2N.

The activity of denitrifying P-accumulating bacteria (DPB) has been verified to exist in most WWTPs with biological nutrient removal (BNR). The modified UCT process has a high content of DPB. A new BNR process with a two-sludge system named A2N was especially developed to exploit denitrifying dephosphatation. With the identical inflow and effluent standards, an existing full-scale UCT-type WWTP and a designed A2N process were evaluated by simulation. The used model is based on the Delft metabolical model for bio-P removal and ASM2d model for COD and N removal. Both processes accommodate denitrifying dephosphatation, but the A2N process has a more stable performance in N removal. Although excess sludge is increased by 6%, the A2N process leads to savings of 35, 85 and 30% in aeration energy, mixed liquor internal recirculation and land occupation respectively, as compared to the UCT process. Low temperature has a negative effect on growth of poly-P bacteria, which becomes to especially appear in the A2N process.

Algorithms↗

PubMed2001

Neuroprotective effects in gerbils of spiramine T from Spiraea japonica var. acuta.

The neuroprotective effects of spiramine T, an atisine-type diterpenoid alkaloid isolated from the Chinese herbal medicine Spiraea japonica var. acuta (Rosaceaee), on cerebral ischemia-reperfusion injury produced by 10-min bilateral occlusion of the common carotid arteries followed by 5-day reperfusion in gerbils were investigated. Intravenous spiramine T (0.38, 0.75, and 1.5 mg.kg-1) markedly reduced the stroke index, enhanced the recovery of EEG amplitude during reperfusion and decreased the concentrations of cortex calcium and LPO in a dose-dependent manner. However, no significant effects on water and sodium contents were observed. These results suggested that spiramine T exhibited protective effects on cerebral ischemia-reperfusion injury in gerbils, and its mechanism might be related to reducing calcium accumulation and lipid peroxidation. This is the first report on spiramine T as a natural product with neuroprotective effects.

Animals↗

PubMed2001

Segmenting high-frequency intracardiac ultrasound images of myocardium into infarcted, ischemic, and normal regions.

Segmenting abnormal from normal myocardium using high-frequency intracardiac echocardiography (ICE) images presents new challenges for image processing. Gray-level intensity and texture features of ICE images of myocardium with the same structural/perfusion properties differ. This significant limitation conflicts with the fundamental assumption on which existing segmentation techniques are based. This paper describes a new seeded region growing method to overcome the limitations of the existing segmentation techniques. Three criteria are used for region growing control: 1) Each pixel is merged into the globally closest region in the multifeature space. 2) "Geographic similarity" is introduced to overcome the problem that myocardial tissue, despite having the same property (i.e., perfusion status), may be segmented into several different regions using existing segmentation methods. 3) "Equal opportunity competence" criterion is employed making results independent of processing order. This novel segmentation method is applied to in vivo intracardiac ultrasound images using pathology as the reference method for the ground truth. The corresponding results demonstrate that this method is reliable and effective.

Algorithms↗

PubMed2001

Contribution of P-bacteria in biological nutrient removal processes to overall effects on the environment.

P-bacteria can combine denitrification and P-uptake. This category of P-bacteria is abbreviated DPB. Use of DPB in BNR processes, instead of obligate aerobic PAOs, reduces oxygen consumption. Moreover, less COD is needed for the nitrogen removal. Non-required COD can be removed by presettling and used for methanation. This leads to a lower sludge production. As a result, CO2 emissions are reduced owing to less net energy consumption. Simulation for a planned WWTP with the BCFS process indicates that DPB can save 53-59% of required COD. The optimal ratios of COD/N and COD/P for simultaneous N and P removal are determined to be 3.9-4.5 and 32.2-35.2 at 12-20 degrees C. 80-95% of particulate COD can be removed from the influent, thereby CH4 production is increased by 154-271%, and the total volume of reactors can be reduced by about 50% compared to a minimised process design. Less net energy consumption over the whole WWTP contributes to a net reduction of the total CO2 emissions up to 16-21%. The energy production from CH4 is excessive enough to balance the energy consumption from aeration, dewatering and incineration. It is concluded that contribution of P-bacteria to saving COD has overall positive effects on the environment.

Bacteria↗

PubMed2000

Antiplatelet and antithrombotic effects of the diterpene spiramine Q from Spiraea japonica var. incisa.

Spiramine Q, a diterpene, was isolated from a Chinese herbal plant Spiraea japonica var. incisa Yu. Born's and Wan HY's methods were used to investigate effects of spiramine Q on rabbit platelet aggregation and serotonin release, respectively. Its antithrombotic effect in mice was also evaluated by Myers' method. Spiramine Q selectively inhibited arachidonic acid-induced platelet aggregation in vitro or ex vivo, and decreased serotonin secretion from rabbit platelets. Spiramine Q (5 mg/kg) decreased the mouse mortality caused by injection of 80 mg/kg arachidonic acid in the tail vein. The results suggested that spiramine Q showed potent antiplatelet and antithrombotic activites.

Animals↗

PubMed2000

Poly

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Journal Article↗

PubMed2000

Maturational differences in soluble guanylate cyclase activity in ovine carotid and cerebral arteries.

Basal cGMP concentrations are greater in immature than in mature cranial arteries, which may help explain why cerebrovascular resistance is lower in neonates than in adults. The present studies explore the hypothesis that this difference derives from age-related differences in soluble guanylate cyclase (sGC) activity. Maturation depressed (p < 0.01) maximal sGC activity (pmol cGMP/mg/min) in both carotid (from 11.10 +/- 0.50 to 3.60 +/- 0.20) and cerebral (from 3.10 +/- 0.31 to 1.45 +/- 0.08) arteries. Western blot analysis of relative sGC abundance (relative to sGC expression in adult kidney) found that sGC abundance was significantly greater (p < 0.05) in newborn carotid (0.38 +/- 0.04) and cerebral arteries (0.37 +/- 0.06) than in adult arteries (0.25 +/- 0.05 and 0.17 +/- 0.03, respectively). Basal Km values in carotid and cerebral arteries did not differ significantly between newborns (3- to 7-d old) and adults. Activation of sGC with nitrosylated heme significantly reduced Km values 3- to 5-fold in both types of artery and in both age groups. Within artery type, maturation had no significant effect on activated Km. Between artery types, activated Km values were greater (p < 0.05) in cerebral (200 +/- 40 microM) than in carotid (80 +/- 10 microM) arteries. Together, these data suggest that variations in sGC substrate affinity contribute to observed differences in sGC activity between artery types but not those between age groups. In contrast, variations in enzyme abundance, and possibly also enzyme-specific activity, appear responsible for differences in sGC activity associated with both age and artery type.

Animals↗

PubMed2000

[Study on the relationships between leptin levels and weights of mothers and infants and the relationships of cord serum leptin to C-peptide, insulin and insulin like growth factor-II].

OBJECTIVE: To determine the relationships between serum leptin levels and maternal weights in late pregnancy and cord blood leptin levels to birth-weights, C-peptide, insulin and insulin like growth factor (IGF-II). METHODS: Fifty normal pregnant women at 37-38 weeks and their newborns were studied, and 29 non-pregnant women were set as control. Venous blood was taken from women and from the cord at delivery. Blood leptin and cord blood C-peptide, insulin, and IGF-II were measured by radio-immunoassay. RESULTS: The average leptin level in maternal sera was (13.62 +/- 3.68) micrograms/L, significantly higher than that in the control (6.60 +/- 3.04) micrograms/L and that in cord blood (8.05 +/- 4.61) micrograms/L. Maternal leptin levels were significantly correlated with maternal weights and body mass index (BMI. r = 0.33, 0.35, P < 0.05), but not with infant birth-weights (r = 0.10, P > 0.05). Cord blood leptin levels were significantly correlated with birth-weights and BMI (r = 0.54, 0.49, P < 0.001) but have no correlation with maternal leptin levels (r = 0.19, P > 0.05). Significant difference of the cord leptin levels was not seen between the males and females. The cord blood C-peptide was (0.86 +/- 0.35) microgram/L, insulin (8.49 +/- 4.76) mU/L and IGF-II (0.218 +/- 0.076) microgram/T. Cord leptin levels were correlated with C-peptide levels (r = 0.37, P < 0.05), but not with insulin and IGF-II levels (r = 0.19, -0.14, P > 0.05). CONCLUSIONS: Maternal leptin levels in late pregnancy were significantly higher than those in normal non-pregnant women and positively correlated with maternal weights and BMI. Cord blood leptin levels were positively correlated with birth-weights and BMI of the newborns. The leptin levels of cord blood were correlated with those of C-peptide but not insulin and IGF-II.

Adult↗

PubMed2000

[The superficial vein, cutaneous nerve and its nutrient vessels in the forearm: anatomic study and the clinical implication].

OBJECTIVE: To provide an anatomic basis for designing the flap pedicled with neurocutaneous nutrient vessels, and for further understanding of this flap and its relations with other local venous flaps. METHODS: Microanatomy and red-and-blue latex injection transparency method were applied to study 1. The medial antebrachial cutaneous nerve (MACN), the lateral antebrachial cutaneous nerve (LACN) and their nutrient vessels; 2. The relationship between the basilic vein and MACN and its nutrient vessels; and 3. The relationship between the cephalic vein and LACN and its nutrient vessels. RESULTS: MACN is vascularized by paraneural vessels and LACN is by both paraneural vessels and the long artery. MACN is accompanied by its paraneural vessels and the basilic vein, so do LACN by its nutrient vessels and the cephalic vein. The distance range from the cutaneous nerve to its accompanying superficial vein is less than 1 cm, to its paraneural vessels is less than 0.4 cm; and the distance range from the paraneural vessel to the superficial vein is about 0.3-1.2 cm. CONCLUSIONS: A flap pedicled with cutaneous nutrient vessels could be designed along a superficial vein. The type of flap might be different because of the different neurocutaneous blood supply. Some locally transferred venous flap might be a flap pedicled with neurocutaneous nutrient vessels.

Adult↗

PubMed2000

[Anatomical study and clinical application of a leg flap pedicle-included with cutaneous nerve and its concomitant vessels].

OBJECTIVE: To investigate the blood supply patterns and the clinical liability of a leg flap pedicle-included with cutaneous nerve and its concomitant vessels. METHODS: Fresh cadaver legs with thirty-two in infants and two in adults were anatomically examined after the intravenous injection of the red Chlorinated Poly Vingl Choride (CPVC). Five patients with the soft tissue defects were selected for the treatment with the flap pedicle-included with the cutaneous nerve and its concomitant vessels. RESULTS: Four main cutaneous nerves were found in the leg after they perforated the deep fascia out. They were companioned with their concomitant vessels with different blood-supply pateeerns, which the upper part of the leg was in an axial pattern and the lower part was in a "chain-type anastomosing" pattern. Following the above-mentioned findings, five cases were successfully treated with this led flap. CONCLUSIONS: The leg flap should be designed along the cutaneous nerve and its concomitant vessels. When the flap is applied in the area of blood supply with "chain-type anastomosing" pattern, the deep fascia should also be included in the flap.

Adult↗

PubMed2000

[The effects of beta-aminopropionitrile on the proliferation in cultrured human hypertrophic scar fibroblasts].

OBJECTIVE: To observe the effects of BAPN on the proliferation in cultured human hypertrophic scar fibroblasts. METHODS: By means of colorimetric MTT(tetrazolium) assay and flow cytometry, we tried to find the effects of BAPN with different concentrations and different time on the proliferation in cultured human hypertrophic scar fibroblasts. RESULTS: Concentrations of BAPN 0.074, 0.222, 0.667, 2.0, 6.0 mg/ml could inhibit proliferation in cultured human hypertrophic scar fibroblasts, but had no effects on cultured human normal dermal fibroblasts. Its ID50 is 2.53 mg/ml. CONCLUSIONS: BAPN could inhibit proliferation in cultured human hypertrophic scar fibroblasts and was dependent on concentration and time.

Adolescent↗

PubMed2000

[Mobilization of autologous peripheral blood stem cells by chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF)].

OBJECTIVE: To observe the efficacy of chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF, Glycosylated) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in autologous peripheral blood stem cells (APBSC) mobilization. METHODS: The mobilization regimen: CBP 350 mg/m(2) intravenously injected at day 1, Vp16 350 mg/m(2) intravenously injected from day 1 to day 3. G-CSF and GM-CSF 5 microg x kg(-1) x d(-1) each, subcutaneously injected and DXM 5 mg/d intramuscularly injected, from the day of white blood cell (WBC) recovery to (2.4 - 6.4) x 10(9)/L from nadir to the day before the end of APBSC harvesting. APBSC harvesting started when WBC > 20.0 x 10(9)/L and ended when accumulated mononuclear cells (MNC) > 5 x 10(8)/kg. CFU-GM assay and CD(34)(+) cells counting of the APBSC were performed. RESULTS: Twenty cases underwent APBSC mobilization. APBSC harvest began at day 22.15 +/- 3.66 for two successive days. Accumulated MNC was (5.93 +/- 1.62) x 10(8)/kg, CD(34)(+) cells (23.10 +/- 11.53) x 10(6)/kg and CFU-GM (3.44 +/- 2.85) x 10(5)/kg. No severe toxicity was observed. Hematopoiesis was well reconstituted in 8 patients received single and in 1 patient received double APBSC transplantations. CONCLUSION: Chemotherapy combined with G-CSF + GM-CSF was a safe and highly effective method for APBSC mobilization.

Adult↗

PubMed1999

The effects of pain severity on health-related quality of life: a study of Chinese cancer patients.

BACKGROUND: The health-related functioning of patients with cancer is compromised by several factors, including the disease process, treatment, and the various symptoms that are produced by both disease and treatment. This study was designed to specify the relationship between patients' pain severity and their self-reported quality of life. METHODS: The study enrolled 216 consecutive consenting adult patients from 2 Chinese cancer centers with pathologically-diagnosed metastatic cancer who could understand and complete the self-report measures. The majority had cancer-related pain and were receiving analgesics. The Chinese version of the Brief Pain Inventory was used to assess the severity and interference of pain. A Chinese translation of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) was used to assess health-related functional status. Patients' physicians completed a form that indicated characteristics of the patients' cancer, Eastern Cooperative Oncology Group performance status, pain, and current pain treatment. RESULTS: Increasing severity of pain was associated with worsening health-related functioning, even when an estimate of disease severity was taken into account. The correlation between pain severity and impairment was nonlinear. The functional health and well-being of cancer patients with no or mild pain was significantly less impaired than that of patients with moderate or severe pain. The impairment of patients with moderate and severe pain did not differ. CONCLUSIONS: Pain severity is an important variable to be taken into account when quality of life outcome measures are considered. The functioning of cancer patients with well-controlled (mild) pain did not differ significantly from that of patients without pain. Providing pain relief should significantly improve the functional status of cancer patients.

Adolescent↗

PubMed1999

Early expression of cyclo-oxygenase-2 during sporadic colorectal carcinogenesis.

Regular administration of non-steroidal anti-inflammatory drugs (NSAIDs) may reduce the incidence of colorectal cancer by targeting cyclo-oxygenase-2 (Cox-2), a key enzyme in arachidonic acid metabolism. To evaluate the role of Cox-2 in sporadic colorectal cancer development, Cox-2 expression was investigated by immunohistochemistry in 85 adenomas, 53 carcinomas, 34 hyperplastic lesions and 104 samples of histologically normal mucosa adjacent to adenoma or carcinoma. In addition, Cox-2 mRNA expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR) in six adenomas and 14 carcinomas with paired grossly normal mucosa. Immunohistochemistry for the proliferation-associated antigen Ki-67 and in situ end labelling for demonstrating apoptotic bodies were also used to analyse the associations between Cox-2 expression and proliferation and apoptosis. Cox-2 protein expression was increased in 76/85 (89.4 per cent) adenomas and 44/53 (83.0 per cent) carcinomas compared with normal mucosa. Cox-2 protein expression was unrelated either to the degree of dysplasia or to the size of the adenomas (p > 0.50, p > 0.10, respectively) or to differentiation, Dukes stage or lymph node metastasis of carcinomas (all p > 0.50). Interestingly, 20/34 (58.8 per cent) hyperplastic lesions adjacent to adenomas or carcinomas displayed expression higher than in normal mucosa (18.3 per cent) (p < 0.0001) but lower than in adenomas or carcinomas (p < 10(-5), p < 0.001, respectively). There were no correlations between Cox-2 protein expression and proliferative or apoptotic index in either adenomas or carcinomas (all p > 0.25). Cox-2 mRNA expression was significantly increased in adenomas and carcinomas compared with normal mucosa (p < 0.005, p < 0.001, respectively). There were no differences between adenomas and carcinomas in either protein or mRNA levels (p > 0.25, p > 0.90, respectively). These data indicate that enhanced expression of Cox-2 occurs early during colorectal carcinogenesis and may contribute to tumour formation.

Adenoma↗

PubMed1999

Changes in the expression of syndecan-1 in the colorectal adenoma-carcinoma sequence.

Syndecan-1, a transmembrane heparan sulphate proteoglycan (HSPG), functions as a matrix receptor on the basal surface of epithelial cells. It also co-localizes with E-cadherin at the lateral cell surface where its function is uncertain. Tumour development in the large bowel is associated with loss of normal epithelial adhesion and altered patterns of expression of cell adhesion molecules, possibly including syndecan-1. To evaluate changes in syndecan-1 expression during the development of colorectal neoplasia, 59 adenomas and 20 carcinomas arising from adenomas were investigated by immunohistochemistry. The staining intensity and distribution of syndecan-1 and E-cadherin in sequential sections was examined, semi-quantified and compared. Staining of syndecan-1 and E-cadherin was uniform in normal colorectal epithelial cells, and located at the basolateral surface. No significant change was seen in either molecule in mildly or moderately dysplastic adenomas. A significant reduction in expression of both syndecan-1 and E-cadherin was seen in severely dysplastic epithelium as compared to moderate dysplasia (P = 0.001 and P = 0.004 respectively). Similarly, there was a significant reduction of both molecules in carcinomas compared with associated adenomas (syndecan-1 P = 0.00003; E-cadherin P = 0.002). In both cases the loss of syndecan-1 expression was more striking than that of E-cadherin. Previous in vitro studies have shown that epithelial cells made deficient in syndecan-1 cease to express E-cadherin, suggesting a causal association. Our results support these findings and indicate that disruption of cell-matrix adhesion is critical in colorectal carcinogenesis, probably preceding changes in the purely homotypic cell-cell adhesion mediated by E-cadherin.

Adenoma↗

PubMed1999

A novel multiscale nonlinear thresholding method for ultrasonic speckle suppressing.

This paper presents a novel speckle suppression method for medical B-scan ultrasonic images. An original image is first separated into two parts with an adaptive filter. These two parts are then transformed into a multiscale wavelet domain and the wavelet coefficients are processed by a soft thresholding method, which is a variation of Donoho's soft thresholding method. The processed coefficients for each part are then transformed back into the space domain. Finally, the denoised image is obtained as the sum of the two processed parts. A computer-simulated image and an in vitro B-scan image of a pig heart have been used to test the performance of this new method. This technique effectively reduces the speckle noise, while preserving the resolvable details. It performs well in comparison to the multiscale thresholding technique without adaptive preprocessing and two other speckle-suppression methods.

Animals↗

PubMed1999

[Preliminary experimental study on free radicals in expanded soft tissue].

OBJECTIVE: To inquire into the formation of free radicals during tissue expansion and its influence on tissue expansion. METHOD: Expanders of 20 ml were placed beneath the dorsal skin of SD rats, and the conventional expansion course took about 23 to 25 days. The activity of SOD and the content of MDA in skin were determined prior to the last expansion, 1 h, 6 h, 12 h and 24 h after the last expansion, respectively. Meanwhile, the effect of SOD on expansion area and length was observed. RESULT: The activity of SOD and the content of MDA at 1 h, 6 h, and 12 h after expansion were significantly different from those before expansion, while the activity of SOD and the content of MDA at 24 h after expansion were almost the same as those before expansion. The difference of expansion area and length between SOD and NS groups was significant, especially during 16 to 24 days. CONCLUSION: Tissue expansion produces free radicals and SOD can increase expansion area and length. The study provides a clue to find a way for safe, rapid and effective soft tissue expansion.

Animals↗

PubMed1999

[Effect of beta-carotene on mouse transplantable mammary cancer MA737].

OBJECTIVE: To study the effect of beta-carotene (BC) on the growth of MA737 in TA II mice. METHODS: BC (250 mg/kg) dissolved in vegetable oil was given per os by gavage once every other day. Mice were treated with BC alone or in combination with chemotherapy (CMF protocol). Control mice were given solvent vehicle. Tumor volume and survival period of the treated and control mice were recorded. RESULTS: In mice treated with BC alone, the growth of the tumor was retarded, but the tumor inhibitory effect was more marked in mice treated with BC + CMF (growth inhibition rate: 49.1% versus 60.5%). The therapeutic effect of combined use of BC and CMF was only slightly better than that of CMF alone. However, BC helped alleviate toxic side effects of the chemotherapeutic drugs so that the survival period was significantly prolonged in the BC + CMF treated mice. Long term treatment with beta-carotene was without side effect. CONCLUSION: beta-carotene inhibits tumor growth, prolongs survival and alleviates toxic side effects of chemotherapy in a mouse mammary cancer model.

Animals↗