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Biomedical subjects

S Zhou

Publications and source records attributed to S Zhou.

At least 109 records · Page 6Linked to original sources
PubMed2001

Reversible binding of the novel anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid to plasma proteins and its distribution into blood cells in various species.

The plasma protein binding and distribution in blood cells of the novel anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) has been investigated in-vitro using filtration and an HPLC method to measure DMXAA. DMXAA (500 microM) was extensively bound in plasma from all species with an unbound fraction (fu) of 4.61+/-1.10 (mouse), 2.59+/-0.32 (rat), 2.02+/-0.48 (rabbit) and 2.07+/-0.23% (human). The binding was concentration dependent with DMXAA concentrations > or = 1,000 microM markedly increasing the fu in the plasma from all species. The estimated number of binding sites in plasma were 2.4+/-0.2 (mouse), 1.7+/-0.2 (rat), 0.8+/-0.1 (rabbit) and 2.1+/- 0.2 (human). The major binding protein in human plasma was albumin, with negligible binding to gamma-globulin and alpha1-acid glycoprotein. There was a significant linear relationship between the bound:free DMXAA concentration ratio (Cb/Cu) and albumin concentration in human serum albumin solution (r = 0.955; P < 0.05) and in healthy human plasma (r = 0.998; P< 0.05), but not in plasma from cancer patients (n = 5), nor across species. In cancer patients (n = 5) DMXAA had a significantly higher (P < 0.05) fu (4.60+/- 0.42%) compared with healthy human plasma (2.07+/-0.23%). In human plasma, the fu of DMXAA (500 microM) was significantly reduced by 500 microM diazepam (P < 0.05), but not by warfarin, phenylbutazone, salicylic acid, ibuprofen or clofibric acid at that concentration. DMXAA significantly reduced the binding of dansylsarcosine (a Site-II binder) to HSA, but significantly increased the binding of dansylamide (a Site-I binder). Within species, the blood:plasma concentration ratio (CBL/CP) of DMXAA was relatively constant (mouse, 0.581+/-0.005; rat, 0.667+/-0.025; rabbit, 0.637+/-0.019; human, 0.673+/-0.103) over the range 50-1000 microM, but increased significantly at DMXAA concentrations > 1000 microM in all species except the rabbit. These results indicate that significant alterations in DMXAA plasma binding and distribution into blood cells occur with increasing concentrations of DMXAA in all species, and also that significant interspecies differences exist. It would be more appropriate to compare plasma unbound concentrations when assessing DMXAA exposure in cancer patients or when extrapolating across species.

Animals↗
PubMed2001

Effect of ubidecarenone on warfarin anticoagulation and pharmacokinetics of warfarin enantiomers in rats.

Interaction between the antioxidant ubidecarenone and the oral anticoagulant warfarin enantiomers was investigated in rats. The decreased hypoprothrombinemic response, assessed by means of percent changes of prothrombin complex activity and clotting factor VII activity, to warfarin, was observed following oral administration of 1.5 mg/kg racemic warfarin to rats during an 8-day oral regimen (10 mg/kg daily) of ubidecarenone. The antioxidant had no apparent effect on the in vitro rat serum protein binding of warfarin enantiomers. Treatment with ubidecarenone did not affect the absorption and distribution of the S- and R-enantiomers of warfarin, but produced a significant increase in the total serum clearance values of both R- and S-warfarin in rats. This effect was more pronounced with R-warfarin than with S-warfarin. The increased clearance values are attributable to acceleration of certain metabolic pathways and renal excretion of the warfarin enantiomers.

Animals↗
PubMed2001

Variation in health and risk behavior among youth living with HIV.

Lifetime and current health practices and risk behaviors were examined among 350 youth living with HIV (YLH) aged 14-23 years from four AIDS epicenters (72.6% male; 26.2% African American, 36.9% Latino). YLH were relatively healthy (M CD4 cells = 499), had used substantial health care and were satisfied with the care. YLH's sexual and substance-use histories indicated substantial HIV related risk acts: the median number of lifetime partners was 25 with only 8% using condoms consistently; 14.9% had injected drugs, and 61.2% had used hard drugs. Compared with females, males had more lifetime and recent sexual partners and had used more drugs. Youth who were recently sexually active (81.3%) had multiple partners. Most of the sexually active YLH used condoms consistently (81.6%). YLH who were symptomatic or had an AIDS diagnosis were likely to have recently had more seropositive sexual partners than the asymptomatic youth. Youth disclosed their serostatus to about half of their sexual partners (53.9%). YLH with AIDS used fewer hard drugs than those without an AIDS diagnosis. Health and risk behaviors of the YLH varied significantly based on their disease stage, gender, and ethnicity, suggesting the need for tailoring interventions for subgroups of YLH.

Adolescent↗
PubMed2001

Carboplatin/paclitaxel or carboplatin/vinorelbine followed by accelerated hyperfractionated conformal radiation therapy: a preliminary report of a phase I dose escalation trial from the Carolina Conformal Therapy Consortium.

The maximum tolerated dose of conformal radiation therapy delivered at 1.6 Gy bid is being assessed in patients with unresectable stage IIB-IIIB non-small cell lung cancer who have been treated with induction regimens consisting of carboplatin plus paclitaxel or carboplatin plus vinorelbine. Data from the early stages of this parallel phase I study show that the two induction regimens are similar in toxicity and that both induce partial responses in 45% of patients. Both regimens can be followed by conformal radiotherapy using an accelerated hyperfractionated schedule to a dose of at least 80 Gy without experiencing unacceptable toxicity. Key morbidity observed thus far has involved the esophagus. Further cohorts of patients will receive higher doses of conformal radiotherapy (in 6.4 Gy increments) until the maximum tolerated dose is reached.

Aged↗
PubMed2001

The thromboxane A2 receptor activates mitogen-activated protein kinase via protein kinase C-dependent Gi coupling and Src-dependent phosphorylation of the epidermal growth factor receptor.

The mitogen-activated protein kinase signaling cascade is used by many G protein-coupled receptors to initiate functional events. In this study, activation of the Gq/G11-coupled thromboxane A2 (TxA2) receptor (TP) by the TxA2 mimetic IBOP in ECV304 cells was found to induce extracellular regulated kinase (ERK) phosphorylation and tyrosine phosphorylation of the epidermal growth factor receptor (EGFR), which were inhibited by the TP antagonist SQ29548, the EGFR kinase inhibitor AG1478, the Src family kinase inhibitor PP1, the Gi/o protein inhibitor pertussis toxin (PTX), or the protein kinase C (PKC) inhibitor calphostin C. TP activation also increased Src kinase activity, which was blocked by PTX, PP1, and calphostin C, but not by AG1478, indicating that Src activation occurs before phosphorylation of EGFR. Blockade of Src activity by expression of dominant negative mutant of Src inhibits mitogen-activated protein kinase (MAPK) activation induced by TxA2. ERK activation induced by the PKC activator phorbol myristate acetate was inhibited by PTX, PP1, AG1478, and calphostin C. In contrast, activation of ERK by lysophosphatidic acid, a Gi-coupled receptor activator, was inhibited by PTX, PP1, and AG1478, but not by calphostin C. Thus, TP-stimulated ERK activation requires Gi, which in turn requires PKC activation. Immunoprecipitation of Galphai showed increased association of Galphai with TPalpha following PKC activation. In conclusion, TPalpha is directly coupled to the Gi protein by a PKC-regulated mechanism; Gi coupling causes Src-dependent transactivation of the EGFR, which is the dominant pathway in TP-mediated ERK activation.

Cell Line↗
PubMed2001

[Phosphorus loss potential of soil-water in sites of the main rice-yield area in the Northern Zhejiang].

Phosphorus (P) loss potential and its environmental impact from soil-water were surveyed in Jiashan Yuyao, Deqing and Yuhang, named main rice-yield areas in Northern Zhejiang province China. High P input has resulted in soil P accumulation. Higher soil Olsen-P contributed its bio-available P, water extracted P and increased soil P loss potential. The role of P in paddy soils is of environmental rather than agronomic concern in the process of soil P build-up. During the no-rice time, total P (TP) concentration in the various water including ditch drain inside/outside field, field surface water and pipe drain et al are over the critical values associated with accelerated waters eutrophication. The average proportion of dissolved reactive P (DRP) concentration in TP was 40%, however, these current DRP levels in partly ditch drain outside field and surface or ground water in no-rice time could not caused serious impact to the outside waters nearby rice-yield agriculture area. No significant line correlation between soil P tests and P in field surface water was found in no-rice time due to differences in field tillage among rice-yield areas, while P application increased both soil P and its correspondingly field surface P level after rice was planted at the same time.

Oryza↗
PubMed2001

Clinical prognosis of patients with early-stage human immunodeficiency virus (HIV) disease: contribution of HIV-1 RNA and T lymphocyte subset quantitation.

Systems for the staging of individuals with human immunodeficiency virus type 1 (HIV-1) infection were developed 15 years ago. Subsequently, assays for quantitating HIV-1 RNA and immunophenotyping of lymphocyte subsets have been developed and validated. The utility of these assays for improved staging in early disease was evaluated in 256 HIV-infected adults (52% minority) with CD4 counts > or = 400 cells/microL followed in U.S. military medical centers before the highly active anti-retroviral therapy era. HIV viral load (RNA) was quantitated; the frequencies of select CD4+ immunophenotypes were determined in 112 subjects. The results were analyzed in relation to three outcome measures: death, first acquired immunodeficiency syndrome-defining opportunistic infection, and CD4 count < or = 200 cells/microL. Serum RNA level and CD4 count were each found to be predictive of all three outcomes. In addition, increases in the T-cell subsets CD28-CD4+ and CD29+CD26-CD4+ were found to be independently predictive of more rapid progression. The classification of early-stage HIV patients is improved by the quantitation of both viral RNA and T-lymphocyte subsets.

Adult↗
PubMed2001

[Dynamic pressure-volume curve predicts the optimal positive end-expiratory pressure in patients with acute respiratory distress syndrome].

OBJECTIVE: To predict the best positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS) patients with dynamic lung pressure-volume (P-V) curve. METHODS: Dynamic and static lung P-V curves were determined in 8 patients with ARDS. The pressure of lower inflection point from dynamic lung P-V curve (Pinfd) was compared with the pressure of lower inflection point from static lung P-V curve (Pinfs). The effect of PEEP on hemodynamics, lung mechanics and gas exchange was observed. RESULTS: When PEEP increased from Pinfd -6 cm H2O to Pinfd +6 cm H2O, partial pressure of arterial oxygen, saturation of arterial oxygen, peak inspiratory pressure and mean airway pressure increased significantly (P < 0.05). Dynamic compliance was improved markedly with PEEP at Pinfd -4 cm H2O when compared with PEEP at Pinfd +6 cm H2O. Cardiac index reduced at Pinf +6 cm H2O. Oxygen delivery was increased at Pinfd -4 cm H2O. When Pinfs and Pinfd were (11.0 +/- 3.2) cm H2O and (12.8 +/- 3.2) cm H2O, they were well correlated (r = 0.99, P < 0.05) and the regression equation was Pinfd = 1.66 + 1.01 x Pinfs. According to the regression equation, it was evident that Pinfd -4 cm H2O equaled to Pinfs -2 cm H2O. CONCLUSION: When ARDS patients are treated with mechanical ventilation, Pinfd -4 cm H2O and Pinfs -2 cm H2O may yield the best PEEP and show maximal oxygen delivery.

Acute Disease↗
PubMed2001

[Epidemiologic survey on mental health of maxillofacial traumatic inpatients].

OBJECTIVE: To Analyze the mental health level of maxillofacial traumatic inpatients. METHODS: The mental test was carried out in 126 maxillofacial traumatic inpatients of Department of Oral and Maxillofacial Surgery of the Fourth Military Medical University from 10/1998 to 09/1999 with the SCL-90 (symptom check list-90). RESULTS: The total mark of SCL-90 was 153.76 +/- 62.44. The number of symptomatic items was 31.52 +/- 24.55, which was higher than that of domestic norm (P < 0.01). The inpatient constitutes at different level of SCL-90 total mark showed normal distribution. The every factor mark of SCL-90 was also higher than that of domestic norm (P < 0.01). The former four factors were melancholy, anxiety, horror and psychosis. The SCL-90 factors mark had an increased trend along with injury severity score (RISS). The age and sex had not notable influence on the mental health level (P > 0.05), but the educational level had notable influence on the mental hralth level (P < 0.05). CONCLUSIONS: The mental health level of maxillofacial traumatic inpatients is lower than normal people and has a decreasing trend along with the RISS. The inpatient that has lower educational level also has lower mental health level. The mental handicap is caused by traumatic event and nosocomial stress.

Adolescent↗
PubMed2001

Reversing drug resistance in the ovarian carcinoma cell line SKOV3/mdr1 in vitro by antisense oligodeoxynucleotides.

OBJECTIVE: To investigate the effect of multidrug resistance gene 1 (mdr1) antisense oligodeoxynucleotides (ODNs) on reversing multidrug resistance in the drug resistant ovarian carcinoma cell line SKOV3/mdr1. METHODS: The ovarian carcinoma cell line SKOV3 transducted with a human multidrug resistance gene (mdr1) served as the drug resistant model (SKOV3/mdr1). The mdr1 antisense ODNs was transfected into SKOV3/mdr1 cells while mediated by lipofectamine. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression and the amount of the mdr1 mRNA in the cells. The positive rate and function of the mdr1 gene product P-glycoprotein (Pgp) in the mdr1 antisense ODNs treated SKOV3/mdr1 cells were determined by flow cytometry and rhodamine 123 efflux. Drug resistance in the SKOV3/mdr1 cell line was observed by MTT assay and cell colony culture. RESULTS: The mdr1 mRNA level was decreased to about 60% of that of beta-actin after mdr1 antisense ODNs treatment. The Pgp positive rate of mdr1 antisense ODNs treated SKOV3/mdr1 cells decreased from 100% to 52.6% (P < 0.01). The intracellular rhodamine 123 retention was increased from 9.1% to 33.8% (P < 0.01). The chemoresistance to taxol decreased to 58% of SKOV3/mdr1 with mdr1 antisense ODN treatment. Compared with SKOV3/mdr1 cells in the control group, under a certain range of drug concentrations, the number of drug resistance colonies in mdr1 antisense ODNs treated SKOV3/mdr1 cells for taxol and doxorubicin decreased by 8.6 +/- 0.8 fold and 3.1 +/- 0.6 fold, respectively. Some non-specific functions during oligodeoxyncleotide treatment was also detected. CONCLUSION: mdr1 expression in the SKOV1/mdr1 cell line was partially inhibited after mdr1 antisense ODNs treatment at the mRNA and protein level, increasing the chemotherapy sensitivity of this drug resistant ovarian carcinoma cell line.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Cordotomy for bilateral cord abductal paralysis.

OBJECTIVE: To investigate the clinical effects of cordotomy on bilateral cord abductal paralysis. METHODS: With unilateral cordotomy, we treated 4 patients with bilateral cord paralysis whose glottis size was about 2.0 mm to 2.5 mm. They were followed up for over one year. RESULTS: One week after surgery, the tracheotomy tubes of all 4 patients were plugged and no dyspnea occurred during rest and mild action. Their voices were more hoarse than before surgery. After 3 months, the tracheotomy tubes were successfully decannulated, and in the following one year, their respiration was normal and then speech was clear, although their voices were still a little hoarse. CONCLUSION: We suggest that cordotomy be one option in the treatment of bilateral cord abductal paralysis.

Adult↗
PubMed2001

[Relations of mechanical properties of human mandible to strain rate and density under tension load].

OBJECTIVE: To study the biomechanical properties of human mandible under tension load and deduce the constitutive equation. METHODS: 100 specimens taken from five mandible of fresh human cadavers were examined on INSTRON by a group of tensile tests at different strain rates (0.0003/s, 0.0030/s, 0.0300/s, 0.3000/s). Bone mineral density of every individual mandible was measured. The effect of strain rate (epsilon), bone mineral density (rho) on young modulus (E), strength (sigma u) and ultimate strain (epsilon u) was studied and the constitutive equation was deduced using the following model: Y = a rho b epsilon c. RESULTS: (1) sigma u = 126.36 rho 1.88 x epsilon 0.044 (P < 0.01), (2) E = 25,170.97 rho 0.44 x epsilon 0.052 (P < 0.01), (3) epsilon u = 0.0088 rho 1.89 x epsilon -0.028 (P < 0.01), (4) sigma u = 6,309.57 rho 0.96 epsilon 0.056 x epsilon 0.80 (P < 0.01). CONCLUSIONS: Strain rate and bone mineral density are important factors for the biomechanical properties of human mandible under tension load. The results above may modelize and characterize the constitutive relation within small strain rates. From the constitutive equation, we could estimate the stress level of the mandible and assess the possibility and degree of mandible injury.

Biomechanical Phenomena↗
PubMed2001

[Analysis of the relation between the operation time and functional recovery for the injured facial motor nerve].

OBJECTIVE: To analyse the relation between the operation time and functional recovery of the facial motor nerve. METHODS: 133 cases of facial motor nerve injury between 1983 and 1998 were involved in this survey. Most of them (130 cases) suffered from traumatic facial palsy. 73 cases were followed up for evaluating their functional recovery of mimic muscles according to the suggestion by the International Muscle Transplant Registry (1991). RESULTS: More than 80% cases of facial nerve injury were sharp cut. There were 28 cases undergone immediate or early repair of the facial nerve, 90 cases secondary repair, 15 cases neuromuscular transfer. The functional recovery was achieved in 24/28 cases in which the broken nerves were immediately or early repaired. CONCLUSIONS: The time to repair the injured motor nerve should be as early as possible, even for the facial palsy caused by tumor or tumor resection. There is still an urgent need to improve the method for objectively evaluating the functional recovery of the facial nerve.

Adolescent↗
PubMed2001

Effects of recombinant human basic fibroblast growth factor on cell proliferation during mandibular fracture healing in rabbits.

OBJECTIVE: To investigate the effects of recombinant human basic fibroblast growth factor (rhbFGF) on the cell proliferation during mandibular fracture healing in rabbits. METHODS: The complex of rhbFGF and bovine type I collagen was implanted into the mandibular fracture site under periosteum of the animal. The whole mandible was harvested at 7, 14, 28, 56 and 84 days respectively after operation. The expression of proliferating cell nuclear antigen (PCNA) in callus was examined with immunohistochemical staining. RESULTS: PCNA-positive cells in callus in the rhbFGF-treated group on days 7 and 14 were more than that in the control group (P<0.01). CONCLUSIONS: It indicates that rhbFGF can stimulate cell proliferation during mandibular fracture healing in rabbits.

Animals↗
PubMed2001

[Ultrasonic multiple measurement estimation of fetal weight in parturient].

OBJECTIVE: To evaluate the ultrasonic measurements of parturient fetal cerebellar diameter (CD), liver length(LL), kidney length (KL) and femur thigh soft tissue thickness(FSTT) for the estimation of fetal weight. METHODS: Ultrasonic measurements of the parturient fetal cerebellar diameter, liver length, kidney length and femur thigh soft tissue thickness were made in 115 cases. The data on these parameters were analyzed with statistical methods, and a multiple linear regressional equation for predicting the fetal body weight was derived. The calculated value of fetal body weight and the estimated parameters of the fetal body were compared with the actually measured values immediately after birth. The error of estimation was analyzed. RESULTS: CD, LL, KL and FSTT were significantly correlated with neonatal birth weight, the coefficient of multiple correlation R = 0.9425 (P < 0.001); among the 115 cases, 101 had absolute error less than +/- 200 g, with an agreement rate of 88%. The sensitivity and accuracy for detection of normal fetus were 98.13% and 94.78% respectively. The multiple linear regression equation derived was BW = -1009.914 + 356.1303FSTT + 354.0682KL + 236.8484 LL + 179.7384 CD. CONCLUSION: The equation is a simple, accurate and valuable equation for the estimation of fetal weight and can be used in clinical practice.

Birth Weight↗
PubMed2001

[Clindamycin soluble suppository-production and its efficacy in treating bacterial vaginosis].

OBJECTIVE: To make the soluble suppository of clindamycin which is an effective drug for treatment of Bacterial vaginosis and to treat patients in clinical trials. METHODS: Outpatients who had vaginal infections from Sept. 1998 to Jan. 1999 were investigated. The diagnoses of bacterial vaginosis were made according to Amsel's criteria and 80 patients were included in this study. They were divided into two groups to be treated respectively by metronidanole suppository and clindamycin suppository which were made by our hospital pharmacy. RESULTS: The cure rate of metronidanole was 87.5% and that of clindamycin 90.3%; No significant difference was noted between the two groups(P > 0.05). The new clindamycin suppository was not irritant and it was easy to dissolve in vagina. There was no discontinued treatment because of side-effect. CONCLUSION: The clindamycin suppository does not irritate the mucosa of vagina, it is an efficacious remedy for bacterial vaginosis.

Administration, Intravaginal↗
PubMed2001

[Study of the changes and effect of VEGF and bFGF in early stage of maxillofacial blast injury in rabbits].

OBJECTIVE: The aim of this study is to determine the content of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the wound fluid during maxillofacial soft tissue blast injury, and to evaluate their effects on angiogenesis of wound healing. METHODS: The rabbit model of maxillofacial blast injury was made by KTY-04 blasting cap. The content of VEGF and bFGF in wound fluid which was collected by using polying alcohol (PVA) sponge, were detected by ELISA. The distributions of VEGF and bFGF in the wound tissue were observed by using the techniques of in situ hybridization and immunohistochemistry. RESULTS: In the wound fluid of maxillofacial blast injury, the content of VEGF was rising steadily at the first week after injury. Comparing with natural sera, it showed difference from the first day after injury, and showed obvious different from the third day (P < 0.01), on which the content was 2.9 ng/ml +/- 2.7 ng/ml. It reached the peak on the seventh day after injury. The bFGF level in wound fluid was 565 pg/ml +/- 436 pg/ml, the peak value was gained at the sixth hour after injury. In the following days, it declined close to the serum level three to five days after injury, and then moved up slightly on the seventh day after injury. The expression of VEGF was located in epithelial cells, vascular endothelial cells and some chronic inflammatory cells. The mRNA transcription of bFGF was present in fibroblasts, endothelial cells and macrophages. CONCLUSION: VEGF and bFGF take part in two angiogenic cascades with synergistic action in maxillofacial blast injury. The bFGF stimulates the initial angiogenesis and induces the production of VEGF. The subsequent and more prolonged angiogenic stimuli can be mediated by VEGF.

Animals↗