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Biomedical subjects

J Zhou

Publications and source records attributed to J Zhou.

At least 685 records · Page 38Linked to original sources
PubMed1997

[Effects of cigarette smoking on antioxidant vitamin and activities of antioxidases].

Levels of plasma vitamin C and E (P-VC, P-VE), beta-carotene (P-beta-Car), lipoperoxides (P-LPO), and activity of erythrocyte superoxide dismutase (E-SOD) were measured in 871 healthy smokers and 348 healthy non-smokers to study the relationship between cigarette smoking and antioxidant vitamins and oxygen free radicals. Results showed that levels of P-VC, P-VE, P-beta-Car and E-SOD reduced significantly, and level of P-LPO increased significantly in smokers, as compared with those in non-smokers. Levels of P-VC, P-VE, P-beta-Car and E-SOD reduced and level of P-LPO increased in 65 male smokers at the same age, with the increase of duration of smoking and quantity of cigarettes smoked, showing a linear correlationship. It suggested that there existed serious imbalance between oxidation and antioxidation in the bodies of smokers, and oxygen free radical reaction and reaction of lipoperoxidation obviously intensified.

Adolescent↗
PubMed1997

[Inhibition of transient outward potassium current in rat ventricular myocytes by propofol].

Whole-cell patch-clamp technique was applied to investigate the effect of propofol (25, 50 mumol/L) on transient outward potassium current (Ito) in rat ventricular myocytes. It was shown that the amplitude of Ito was decreased significantly after exposure to propofol. The effect is partially reversible after washing. At applied potential > or = 0 mV, statistical significant differences reached between propofol (25 and 50 mumol/L) group and the control group could be found. The voltage-dependent manner and the outward rectifier character were not affected by the drug at the two concentrations. It seems possible that the inhibition of potassium channels by propofol could underlie, at least in part, its beneficial effects in various cardiovascular diseases, including certain types of cardiac arrhythmia.

Anesthetics, Intravenous↗
PubMed1997

Adenovirus-mediated delivery of p16 to p16-deficient human bladder cancer cells confers chemoresistance to cisplatin and paclitaxel.

We have previously established the efficacy of adenoviral gene delivery vectors for the treatment of bladder carcinoma in vivo. In the present work, we developed a gene therapy strategy for bladder cancer based on the replacement of the tumor suppressor p16, which is known to be mutated or deleted in a variety of human tumors, including those derived from the bladder. Previous reports have demonstrated that reconstitution of p16 has marked effects on the proliferative capacity of tumor cell lines both in vitro and in vivo, and that p16 expression causes resistance to some chemotherapeutic agents. In the present study, we describe the construction of the recombinant adenovirus Adp16, expressing the p16 gene, to evaluate the effects of transient p16 replacement in the context of bladder carcinoma. To identify candidate target cell lines, we screened a panel of bladder cancer cell lines for p16 and retinoblastoma (RB) protein expression. We demonstrate that Adp16 can mediate high-efficiency p16 replacement to the p16-negative cell lines EJ and UMUC-3. In addition, the reconstitution of p16 to the highly transducible p16-negative, RB-positive bladder cancer cell line EJ caused a profound inhibition of cell proliferation mediated by arrest in the G1 phase of the cell cycle. In contrast, the p16-positive, RB-negative cell line J82 was unaffected by this treatment. However, when adenovirally mediated p16 replacement was combined with the chemotherapeutics cisplatin and paclitaxel, a marked chemoresistance was observed in genetically corrected cells. This work has implications for future gene therapy strategies based on p16 replacement.

Adenoviridae↗
PubMed1997

[Clinical and experimental study on improving cellular immunological function of uterine myoma patients by xiaoliu tablet].

OBJECTIVE: To explore the effect of Xiaoliu Tablet (XLT) in treating uterine myoma (UM) and the relationship between effect and the cellular immunological function of the UM patients. METHODS: Seventy-one UM patients by treatment with XLT was observed. The activities of natural killer (NK) cells of 50 patients and 30 normal women were determined. RESULTS: There were good effect in reducing the volume of myoma and improving the menses by XLT, especially in patients whose myoma were singly and small. The activity of NK cells of these patients (24.61 +/- 6.04%, n = 50) was significantly different from that of normal women (45.42 +/- 9.05%, n = 30), P < 0.01. There was a notable rise of NK cells of the patients (37.54 +/- 5.01%, n = 39), after the treatment of six months by XLT (P < 0.01). CONCLUSION: Improving the immunological function might be one of the mechanisms of the effect of XLT.

Adjuvants, Immunologic↗
PubMed1997

[The study of epidermal growth factor in acceleration of skin wound healing].

In order to investigate the function of epidermal growth factor (EGF), the following experiments were performed. Thirty white rats were chosen and divided into 3 groups. In the back of each rat, two 2 cm x 2 cm wounds were made bilaterally, the skin and subcutaneous tissue was removed. EGF were used in one of the two wounds randomly, while those without EGF usage in control. After 1, 2 and 3 weeks, the rats were sacrificed. The area of the wounds was measured, and the healing time of each wound was recorded. The results showed that the healing time of EGF group was 14.6 days while that of control group was 18.5 days (P < 0.01). Furthermore, the DNA, protein and hydroxyproline contents of EGF group were higher than those of the control group (P < 0.01). It was suggested the EGF could accelerate wound healing and shorten the healing time.

Animals↗
PubMed1997

[Internal fixation with U-shaped pin in the treatment of fracture-dislocation of the cervical spine].

Twenty cases with fracture-dislocation of the cervical spine were treated by U-shaped pin fixation. The U-shaped pin made of Steiman pin was used to hold sublaminar fixation of two segments above and below the vertebra of fracture. When atlas or axis was injured, a pair of small holes were drilled on the occipitale. The closed end of the U-Shaped pin was wired through the holes. Early postoperative ambulation was allowed without external fixation. 18 cases were followed up for 8-35 months. 5 cases of six patients with neurologic deficits recovered completely. The remaining one improved, no failure or loosening of the U-Shaped pin or wires was observed. Sound union of the bone grafts was obtained in all the patients. The results suggest that the operative procedure is simple, with sound fixation and satisfactory reduction and union of the fractures.

Adolescent↗
PubMed1997

[A clinicopathological immunohistochemical and cytomorphometric study on midline T cell lymphoma].

One hundred and twenty-two cases of midline malignant reticulosis (MMR) were studied. A series of antibodies including anti-LCA, UCHL-1, L26, CD45R, and anti-lysozyme were used on paraffin sections by ABC and PAP methods. The results were as follows: 112 cases exhibiting T-cell origin, 4 cases showing B-cell origin, and 6 cases being of uncertain lineage. This result is in accordance with the point of view that most of MMR are T cell lymphoma. Two histological types were classified: sarcomatoid type and granulomatoid type. By using image analyzer, the sarcomatoid type was subdivided into small, medium and large cell types. Sixty-two cases with follow-up data were collected for clinicopathologic analysis. One-year and five-year survival rates in cases with different histologic types were compared and statistically analysed. The results showed that the prognosis was closely related to the histological type.

Adolescent↗
PubMed1997

[Preliminary evaluation on bone mass of tibia by ultrasonic measurement].

The speed of ultrasound (SOS) in right middle tibia and bone mineral density (BMD) of left radius at the distal one-third were measured by ultrasonic measurement and single photoabsorptionmetry in 260 healthy individuals simultaneously. SOS of tibia was positively correlated with BMD of radius (r = 0.64). The peak bone mass of both measurements was at 33 to 36 years of age. Height was positively correlated with the SOS of tibia, while weight was positively correlated with SOS of female tibia, period of menopause negatively correlated with female's SOS of tibia. The concordance of SOS of tibia and BMD of radius in diagnosis of osteoporosis was 36.8%. The results suggest that ultrasonic measurement of tibia is an effective method of bone mass measurement.

Adolescent↗
PubMed1997

[Image analysis of tumor cells from common intracranial neoplasms on frozen and paraffined slices].

Image analysis technique was used to measure four parameters [the form factor (FF), area, perimeter and diameter] of nuclei in 76 cases of common intracranial tumors on forzen and paraffined slices. The results showed that the area, perimeter, diameter of nuclei on frozen slices were much larger than those on paraffined slices while the FF showed no significant difference between two kinds of slices (P > 0.05). The parameters of the area, perimeter, and diameter of nuclei on two kinds of slices became larger and the parameters of FF became smaller as the grade of astrocytoma ascended. It is considered that the results of present study will be helpful to the diagnosis of common intracranial tumors on frozen slices.

Astrocytoma↗
PubMed1997

[Comparison between intraarterial pulsegraphy and thermodilution method for determination of cardiac output during anesthesia and operation in patients undergoing cardiac valve replacement].

Comparison of intraarterial pulsegraphy and standard thermodilution methods for determination of cardiac output (CO) in 14 patients with poor cardiac function following valve replacement operation was performed. The CO, cardiac index (CI) were moderate to high correlated between the two methods before and after valve replacement respectively. The study indicates that intraarterial pulsegraphy provides a continous method of determining CO in patients with poor cardiac function during operation.

Adult↗
PubMed1996

The BDNF content of postnatal and adult rat brain: the effects of 6-hydroxydopamine lesions in adult brain.

Brain-derived neurotrophic factor (BDNF) has been well studied for its effects in improving survival and differentiation of the central and peripheral nervous system. In order to understand the developing CNS and the pathogenesis of brain injury, an enzyme immunoassay was employed to detect BDNF protein in the various tissues of developing and adult animals. Increased levels of the BDNF were found in the hippocampus, cerebrocortex, striatum, cerebellum and ventral mesencephalon in 2-week-old rats, compared with that in postnatal day 0 pups. In the adult rat, the highest level of BDNF was detected in the hippocampus (14.5 +/- 0.8 ng/g wet tissue), with a relatively high level also observed in the cerebrocortex and striatum. In peripheral tissues, a substantial amount of BDNF protein was observed in various organs. The changes in BDNF levels in the striatum and the ventral mesencephalon of unilaterally 6-hydroxydopamine-lesioned young adult rats were also examined. Significant increases of BDNF levels were detected during 2 weeks after lesion.

Analysis of Variance↗
PubMed1996

Initiation of Plant Disease Resistance by Physical Interaction of AvrPto and Pto Kinase

Resistance to bacterial speck disease in tomato occurs when the Pto kinase in the plant responds to expression of the avirulence gene avrPto in the Pseudomonas pathogen. Transient expression of an avrPto transgene in plant cells containing Pto elicited a defense response. In the yeast two-hybrid system, the Pto kinase physically interacted with AvrPto. Alterations of AvrPto or Pto that disrupted the interaction in yeast also abolished disease resistance in plants. The physical interaction of AvrPto and Pto provides an explanation of gene-for-gene specificity in bacterial speck disease resistance.

Journal Article↗
PubMed1996

The Fab-7 element of the bithorax complex attenuates enhancer-promoter interactions in the Drosophila embryo.

Enhancers integrate positive and negative regulatory information to direct localized patterns of gene expression in the Drosophila embryo. Here we present evidence for the occurrence of cis regulatory elements that control the levels of gene expression by modulating enhancer-promoter interactions. For this purpose we have investigated the Drosophila bithorax complex (BX-C) because genetic studies suggest that the BX-C contains as much as 300 kb of cis regulatory information. A specialized DNA element, Fab-7, has been proposed to function as a boundary element that separates the iab-6 and iab-7 cis regulatory regions within the Abd-B domain of the BX-C. A 1.2-kb Fab-7 DNA fragment was placed between divergently transcribed white and lacZ test promoters and challenged with several defined enhancers expressed in the early embryo. These studies suggest that Fab-7 functions as an attenuator, which weakens gene expression by reducing enhancer-promoter interactions. Fab-7 selectively blocks distal enhancers in an orientation-independent fashion, and can function when located far from either the distal enhancer or target promoter. Fab-7 may be related to insulator DNAs, which flank genetic loci and functionally isolate neighboring genes. We propose that specialized DNA elements, such as the Fab-7 attenuator, might play a general role in controlling the levels of gene expression by modulating enhancer-promoter interactions.

Animals↗
PubMed1996

Identification and localization of polycystin, the PKD1 gene product.

Polycystin, the product of autosomal dominant polycystic kidney disease (ADPKD) 1 gene (PKD1) is the cardinal member of a novel class of proteins. As a first step towards elucidating the function of polycystin and the pathogenesis of ADPKD, three types of information were collected in the current study: the subcellular localization of polycystin, the spatial and temporal distribution of the protein within normal tissues and the effects of ADPKD mutations on the pattern of expression in affected tissues. Antisera directed against a synthetic peptide and two recombinant proteins of different domains of polycystin revealed the presence of an approximately 400-kD protein (polycystin) in the membrane fractions of normal fetal, adult, and ADPKD kidneys. Immunohistological studies localized polycystin to renal tubular epithelia, hepatic bile ductules, and pancreatic ducts, all sites of cystic changes in ADPKD, as well as in tissues such as skin that are not known to be affected in ADPKD. By electron microscopy, polycystin was predominantly associated with plasma membranes. Polycystin was significantly less abundant in adult than in fetal epithelia. In contrast, polycystin was overexpressed in most, but not all, cysts in ADPKD kidneys.

Antibodies↗
PubMed1996

Endocytosis of activated TrkA: evidence that nerve growth factor induces formation of signaling endosomes.

The survival, differentiation, and maintenance of responsive neurons are regulated by nerve growth factor (NGF), which is secreted by the target and interacts with receptors on the axon tip. It is uncertain how the NGF signal is communicated retrogradely from distal axons to neuron cell bodies. Retrograde transport of activated receptors in endocytic vesicles could convey the signal. However, little is known about endocytosis of NGF receptors, and there is no evidence that NGF receptors continue to signal after endocytosis. We have examined early events in the membrane traffic of NGF and its receptor, gp140(TrkA) (TrkA), in PC12 cells. NGF induced rapid and extensive endocytosis of TrkA in these cells, and the receptor subsequently moved into small organelles located near the plasma membrane. Some of these organelles contained clathrin and alpha-adaptin, which implies that TrkA is internalized by clathrin-mediated endocytosis. Using mechanical permeabilization and fractionation, intracellular organelles derived from endocytosis were separated from the plasma membrane. After NGF treatment, NGF was bound to TrkA in endocytic organelles, and TrkA was tyrosine-phosphorylated and bound to PLC-gamma1, suggesting that these receptors were competent to initiate signal transduction. These studies raise the possibility that NGF induces formation of signaling endosomes containing activated TrkA. They are an important first step in elucidating the molecular mechanism of NGF retrograde signaling.

Animals↗