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Biomedical subjects

Z Cao

Publications and source records attributed to Z Cao.

At least 199 records · Page 11Linked to original sources
PubMed1996

[A study of intraarticular irrigation-injection therapy of temporomandibular joint and its mechanism].

According to the research that there were some immune and inflammatory substances in the synovial fluid of temporomandibular joint disturbance syndrome (TMJDS), we improved the traditional intraarticular injection and developed an intraarticular irrigation-injection therapy to treat 43 cases of TMJDS and got a good result. The controls include two groups, the simple rinsing and the traditional injection. Statistical analysis showed a highly significant difference in the effects between test and control groups. In order to study the mechanism of the therapy, the tumor necrosis factor (TNF) in synovial fluid of 8 cases were assessed. It was found that the concentration of TNF was reduced markedly after treatment. We think that the new therapy is effectable for TMJDS and could be used widely.

Adult↗
PubMed1996

[The value of CA125 and LDH assays in assisting diagnosis of epithelial ovarian carcinoma].

40 first-treated cases of epithelial ovarian cancer, 13 cases of cervical cancer, 13 cases of corpus cancer and 50 cases of benign tumor were included in this study from Jan. 1991 through May 1992 to evaluate the significance of the blood CA125, LDH, CR and SA levels in assisting diagnosis of epithelical ovarian cancer. The CA125 levels of the 40 canses of ovarian cancer were higher than those of cervical cancer and corpus cancer (P < 0.05); the SS, PLR and AC of CA125 in ovarian cancer were higher than those of LDH, SA and CR (P < 0.05); the SS of CA125 in ovarian cancer was higher than that of LDH isoenzyme (P < 0.05). The results show that CA125 may be the best tumor marker in assisting ovarian cancer; CA125 is more informative than LDH, CR and SA; when CA125 is used incombination with other tumor markers, SS, SP, NPV and PPV can be greatly raised.

Biomarkers, Tumor↗
PubMed1995

Characterization of the 5'-flanking region of the gene for the gamma chain of human fibrinogen.

The 5'-flanking region of the gene coding for the gamma chain of human fibrinogen was characterized for its promoter activity. Reporter gene studies using chloramphenicol acetyltransferase as the indicator along with mutations in the DNA showed that a TATA-like sequence (-20 to -23 base pairs (bp)), a CAAT-like sequence (-54 to -57 bp), and an upstream stimulatory factor (USF) binding site (-66 to -77 bp) constitute a minimal promoter that mediates liver-specific expression of the gene. Electrophoretic gel mobility assays and antibody binding studies confirmed the interaction of USF with the binding site. An IL-6 responsive element with a sequence of CTGGAA located at -301 to -306 bp was shown to be a functional element in the IL-6 response. In contrast to the IL-6 responsive elements in the human alpha- and beta-fibrinogen genes, the element in the gene for the gamma chain of human fibrinogen was unaffected by the presence or elevated levels of the beta or delta isoforms of the CCAAT/enhancer binding proteins. A negative element with sequence homology to several silencer elements was also identified in the region of -348 to -390 bp of the gene for the gamma chain of human fibrinogen. A comparison of the regulatory elements in the genes coding for all three chains in fibrinogen is also presented.

Amino Acid Sequence↗
PubMed1995

NF-kappa B activation by interleukin-1 (IL-1) requires an IL-1 receptor-associated protein kinase activity.

An important function of interleukin-1 (IL-1) is activation of the transcription factor NF-kappa B, which is signaled via the type I IL-1 receptor (IL-1RI). By receptor mutagenesis studies, we have identified a region of the cytoplasmic domain of IL-1RI that is required for both IL-1-mediated NF-kappa B activation and IL-1-dependent activation of a receptor-associated protein kinase activity we term IRAK. No IL-1RI mutants were found that can activate NF-kappa B in the absence of IRAK activity. Therefore, we propose that IRAK activation is a necessary step in the activation of NF-kappa B by IL-1.

Cells, Cultured↗
PubMed1995

Cascade regulation of terminal adipocyte differentiation by three members of the C/EBP family of leucine zipper proteins.

Terminal differentiation of cultured 3T3-L1 fibroblasts to the adipogenic phenotype is potently stimulated by dexamethasone (DEX) and methylisobutylxanthine (MIX). Previous studies have shown that these hormones induce the expression of genes encoding two members of the CCAAT/enhancer binding protein (C/EBP) family of transcription factors. In the absence of new protein synthesis DEX activates the gene encoding C/EBP delta. Likewise, MIX is a direct inducer of C/EBP beta gene expression. Optimal conditions for differentiation entail a 2-day period wherein confluent fibroblasts are exposed to DEX and MIX, followed by removal of the hormones and subsequent culture in the presence of insulin and fetal bovine serum. During the early phase of differentiation, high levels of C/EBP delta and C/EBP beta accumulate. These transcription factors diminish during the terminal phase of differentiation and come to be replaced by a third member of the C/EBP family, C/EBP alpha. Conclusive evidence has already shown that C/EBP alpha regulates terminal adipocyte differentiation, turning on the battery of fat-specific genes required for the synthesis, uptake, and storage of long chain fatty acids. Here we provide evidence that C/EBP delta and C/EBP beta play early catalytic roles in the differentiation pathway, relaying the effects of the hormonal stimulants DEX and MIX in a cascade-like fashion, leading to the activation of the gene encoding C/EBP alpha. Conditions facilitating the precocious expression of either C/EBP delta or C/EBP beta were observed to accelerate adipogenesis and, in the case of C/EBP beta, relieve dependence on the early hormonal stimulants. Likewise, conditions that prevented the expression of functional C/EBP beta effectively blocked terminal differentiation. Finally, we have discovered that ectopic expression of C/EBP beta in multipotential NIH-3T3 cells results in their conversion into committed adipoblasts capable, upon hormonal stimulation, of synchronous and uniform differentiation into fat-laden adipocytes.

1-Methyl-3-isobutylxanthine↗
PubMed1995

GABAB receptor-mediated effects in synaptosomes of lethargic (lh/lh) mice.

Previously, we have shown a significant increase in number of GABAB receptor binding sites in neocortex and thalamus of lethargic (lh/lh) mice, a mutant strain exhibiting absence seizures. This study was performed to test our hypothesis that presynaptic GABAB receptors would inhibit [3H]GABA release to a greater degree in lh/lh mice compared with their nonepileptic littermates (designated +/+). Synaptosomes isolated from neocortex and thalamus of age-matched male lh/lh and +/+ mice were similar in uptake of [3H]GABA. In the neocortical preparation, baclofen dose-dependently inhibited [3H]GABA release evoked by 12 mM KCl, an effect mediated by GABAB receptors. The maximal inhibition (Imax) value was significantly greater (80%) in lh/lh than +/+ mice, whereas the IC50 (3 microM) was unchanged. In the thalamic preparation, the effect of baclofen (50 microM) was 58% less robust in lh/lh mice. Other effects mediated by GABAB receptors (inhibitions in Ca2+ uptake and cyclic AMP formation) were also significantly reduced in thalamic synaptosomes from lh/lh mice. These data suggest a greater presynaptic GABAB receptor-mediated effect in neocortex and a reduced effect in thalamic nuclei of lh/lh mice. It is possible that selective effects of presynaptic GABAB receptors or GABA release in neocortex and thalamic nuclei of lh/lh mice may contribute to mechanisms underlying absence seizures.

Animals↗
PubMed1995

Neural network of structures in which GABAB receptors regulate absence seizures in the lethargic (lh/lh) mouse model.

In previous work we have shown that GABAB receptors are required for expression of absence seizures in the lethargic (lh/lh) mouse model; that lh/lh mice have increased numbers of GABAB binding sites compared to nonepileptic littermates (designated +/+); and that the magnitude of the increased number of GABAB receptors in lh/lh mice correlated positively with the frequency of absence seizures. We performed this study to delineate the neural network in which GABAB receptors regulate absence seizures in lh/lh mice. We designed three successive screens which had to be passed by a candidate neuronal population before it could be considered a member of the neural network in which GABAB receptors regulate absence seizures. First, the neuronal populations in lh/lh mice had to have enriched GABAB binding sites compared to homologous populations in matched nonepileptic controls; baclofen-displaceable 3H-GABA binding was measured in autoradiograms for this screen. Second, the candidate populations had to generate spike-wave discharges (SWDs) during absence seizures in lh/lh mice; bipolar recording electrodes implanted into candidate neuronal structures were used in this screen. Third, the candidate populations had to demonstrate GABAB receptor-mediated regulation of absence seizures in lh/lh mice; microinjections of a GABAB agonist [(-)-baclofen] and antagonist (CGP 35348) were used for this screen. In this study we found that anterior ventral lateral thalamic nucleus (VLa), nucleus reticularis thalami (NRT), nucleus reuniens (RE) passed all three screens, and hence are members of the neural network in which GABAB receptors regulate absence seizures in lh/lh mice.

Animals↗
PubMed1995

Detection of human papillomavirus types 16, 18 DNA related sequences in bronchogenic carcinoma by polymerase chain reaction.

In studying the relationship between human papillomavirus (HPV) and bronchogenic carcinoma, "high-risk" HPV 16, 18 DNA sequences were detected in samples from 50 lung cancer patients, 18 patients with benign pulmonary diseases and 4 fetal lung tissues by polymerase chain reaction (PCR) and dot-blot hybridization with biotin-labelled probes. The results showed that HPV 16, 18 DNA related sequences were found in 32% of lung cancer specimens, with 10 cases of HPV 16, 5 cases of HPV 18 and 1 case of both types. 48.15% (13/27) of squamous cell carcinomas were shown to be positive for HPV 16, 18 DNA. In addition, two adenocarcinomas and one small cell carcinoma were positive for HPV 16 DNA. No specimens from benign diseases tissues and fetal lung tissues showed positive results. These results suggest that primary bronchogenic carcinoma is related to HPV infection.

Adenocarcinoma↗
PubMed1995

[Chemotherapy against lymphatic metastases of gynecologic cancer via pelvic retroperitoneal cannulation: a preliminary report].

Lymphatic metastasis is one of the most important problems in the treatment of gynecologic malignancy. We conducted a preliminary investigation on the feasibility and practicality of chemotherapy against lymphatic metastases of gynecologic cancer via pelvic retroperitoneal cannulation. 5-FU mixed with Isovist-300 was injected into the pelvic retroperitoneal space. X-ray films revealed that the external iliac, hypogastric, obturator, deep inguinal and most of the common iliac lymph nodes were submerged in the 5-FU solution. 5-FU concentrations in the lymph nodes were measured by high pressure liquid chromatography, which showed that 5-FU concentration of the study group was 2 to 10 times that of the control group. Pathologic findings revealed that most of the metastatic cancer cells in the study group showed obvious degeneration and necrosis while no changes were observed in the control group. No major complications or adverse effects were observed. Our results suggest that this method may be used to treat the lymphatic metastases of gynecologic cancer.

Adenocarcinoma↗
PubMed1995

Differences in the anatomic distribution of immediate-early gene expression in amygdala and angular bundle kindling development.

Kindling is a model in which fleeting changes of neuronal activity produce a lifelong modification of neuronal structure and function in the mature nervous system. Immediate-early genes (IEGs) such as c-fos have been implicated as a causal link in the chain of molecular events coupling fleeting pathologic activity to lasting hyperexcitability. Identification of the brain structures exhibiting IEG expression during the evolution of kindling is necessary to guide investigations of the phenotypic consequences. We used in situ hybridization histochemistry to identify the structures exhibiting expression of multiple IEGs during the evolution of amygdala kindling and compared this to the pattern following angular bundle kindling. The principal findings included that: (1) generalized limbic and clonic motor (class 5) kindled seizures evoked by stimulation of one amygdala induced the expression of IEGs in a small subset of limbic structures with remarkable symmetry between the two hemispheres; (2) the anatomic extent of seizure-evoked expression of c-fos mRNA expanded progressively following focal limbic and motor (classes 0-3) seizures during the development of amygdala kindling; c-fos mRNA was detected first ipsilaterally in AM, ACO, and PC and with higher-class seizures in hippocampal formation and homologous structures contralaterally, and (3) class 5 seizures evoked by stimulation of two different sites in the limbic system (amygdala or angular bundle) induced IEG expression in distinct but partially overlapping anatomic structures. We propose that synaptic activation of glutamate receptors contributes to the expression of these diverse IEGs throughout the forebrain. The findings provide a constellation of anatomic structures in which to investigate the structural and functional consequences of IEG expression.

Amygdala↗
PubMed1995

Pentoxifylline ameliorates pulmonary damage caused by Streptococcus pneumoniae infection in mouse.

Streptococcus pneumoniae stimulated mouse peritoneal macrophage to release tumor necrosis factor-alpha (TNF alpha) in vitro. When penicillin was added into the medium with bacteria, TNF alpha release was accelerated. Pentoxifylline (PTX), a phosphodiesterase inhibitor, significantly attenuated TNF alpha release caused either by Streptococcus pneumoniae or by its lysates. In this experiment, 150 Kunming mice were infected with Streptococcus pneumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were determined, and pulmonary pathological changes were also observed. It was found that PTX significantly attenuated TNF alpha activity in serum and bronchoalveolar lavage fluid, and inhibited white blood cell chemotaxis, emigration and infiltration. In conclusion, Streptococcus pneumoniae infection stimulates the release of TNF alpha which is probably the major mediater that causes tissue damage during Streptococcus pneumoniae infection. The mechanism is probably that Streptococcus pneumoniae and its lysates activate TNF alpha gene transcription. As penicillin accelerates TNF alpha release, treatment with penicillin alone may aggravate the tissue damage. Combined treatment with PTX may be more reasonable.

Animals↗
PubMed1995

[Clinical and experimental researches in the inhibition of bile pigment lithogenesis by acupuncture and moxibustion].

Clinical subjects were the patients in whom cholecystectomy and choledochotomy were performed with T tube drainage. Four groups of acupoints were established according to different point prescriptions. Under the strict control of experimental conditions and fixation of electrical acupuncture stimulation parameters, the changes of hepatic bile output were observed in five different stages before, during and after acupuncture, and compared with those in control group not treated by acupuncture. The results showed that electrical acupuncture of Ganshu (Back-Shu point) (GB 18) and Qimen (Front-Mu point) (LI 14) could obviously promote the secretion of hepatic bile. The immediate effect was superior to that in other groups. In a group not treated by acupuncture, hepatic bile output gradually decreased as time went on. In animal experiment, a model of bile pigment lithogenesis was made in guinea pig. The animals were randomly divided into five groups of control, simultaneous acupuncture, simultaneous moxibustion, re-acupuncture after one week and re-acupuncture after two weeks. The results indicated that electrical acupuncture or moxibustion of relevant acupoints such as Ganshu (GB 18) and Qimen (LI 14) could really very effectively inhibit the animal lithogenesis caused by lithogenesis food. A tendency was observed towards that the earlier acupuncture was performed, the better the preventive effect on lithogenesis. In the influence on lithogenesis bile, both acupuncture and moxibustion could reduce the contents of biliary total bilirubin and free bilirubin and the activity of biliary beta-glucuronidase. Acupuncture also produced an effect in lowering hepatic beta-glucuronidase but moxibustion didn't. Hepatohistological observation showed that lithogenous food could also cause fatty degeneration of liver, and moxibustion could markedly inhibit its progress. Both acupuncture and moxibustion didn't remarkably influence the content of serum cholesterol.

Animals↗
PubMed1994

Regulatory elements and transcription factors controlling basal and cytokine-induced expression of the gene encoding intercellular adhesion molecule 1.

The gene encoding intercellular adhesion molecule 1 (ICAM-1) is transcriptionally induced in response to inflammatory and immunomodulatory cytokines. To investigate the mechanisms controlling ICAM-1 gene expression, we have identified regulatory DNA sequences responsible for maintaining basal and mediating induced transcription in response to tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma). Regulatory elements centered 115, 60, and 40 bp upstream from the ICAM-1 transcription start site were implicated in cytokine-independent gene expression. Regulatory elements dedicated to TNF-alpha and IFN-gamma were identified 190 and 90 bp, respectively, upstream from the ICAM-1 transcription start site. A combination of mutagenesis and DNA-binding assays revealed that the TNF-alpha response element is composite, consisting of binding sites for both C/EBP and NF-kappa B. The IFN-gamma response element behaved as a simple regulatory element that selectively binds to an IFN-gamma-inducible activity composed, at least in part, of p91. These observations provide a framework for understanding how extracellular signals dynamically regulate the adhesive properties of mammalian cells.

Base Sequence↗