Adenoviral transfer of xenogeneic MHC class I gene results in loss of tumorigenicity and inhibition of tumor growth

The immune system confers protection against a variety of pathogens and contributes to the destruction of neoplastic cells. Foreign major histocompatibility complex (MHC) protein serves as a potent stimulus to the immune system. In this report, a mouse H-2Kb gene was introduced into two poorly immunogenic tumor cell lines, a mouse colonic carcinoma cell line, MCA-26 (H-2Kd), and a rat mammalian carcinoma cell line, LN-4, in an effort to stimulate tumor rejection. Our results showed that the expression of xenogeneic MHC class I antigen completely abolished the LN-4 tumorigenicity in rats, whereas the expression of allogeneic MHC class I antigen only partially reduced the MCA-26 tumorigenicity in mice. Rats with tumor regression of LN-4/H-2Kb developed a T helper type 1-dominant response, whereas rats with LN-4 tumor growth developed a T helper type 2-dominant response. The immunized rats that experienced LN-4/H-2Kb tumor regression further developed protective immunity against a subsequent challenge of LN-4 cells. This protective immunity was mediated by the LN-4 tumor-specific cellular immune response against both the transduced and the parental LN-4 cells. Recombinant adenoviral vectors are highly efficient at in vitro and in vivo gene delivery. The LN4 cells transfected with the recombinant adenovirus AdV-H-2Kb in vitro expressed the cell surface H-2Kb molecule by fluorescence-activated cell sorter analysis. Adenovirus-mediated H-2Kb gene transfer in vivo can further significantly inhibit pre-established LN-4 tumors. Those rats with complete tumor regression further developed protective immunity against the subsequent challenge of a parental LN-4 tumor. Therefore, our study indicates that the adenovirus-mediated transfer of xenogeneic MHC class I gene may be an effective alternative to the current protocol of cancer gene therapy in which the allogeneic MHC class I gene is used.

[Research on stochastic factors of heart rhythm variability in nonlinear dynamic analysis]

In this study, the influence of external noise on heart rhythm variability (HRV) in nonlinear dynamic analysis and the internal stochastic factor of HRV were discussed in connection with their physiological significance. The sampling rate, stationary and non-uniformity time interval were analyzed. An interpolation algorithm for heart period was introduced. The experiment demonstrated that the influence was highly reduced by the mentioned procedure. The internal stochastic factors of HRV were investigated by several nonlinear dynamic methods such as surrogate data, mutual information and nonlinear forecasting. The results suggested the colligation of deterministic chaos and stochastic process should be a favorite to interpret HRV.

Polymorphisms at - 174 and in the 3' flanking region of interleukin-6 (IL-6) gene in patients with myasthenia gravis

We examined the bi-allelic polymorphism at - 174 in the promoter region and the polymorphism in the 3' flanking AT rich region of the interleukin-6 (IL-6) gene in Swedish patients with myasthenia gravis (MG) and ethnically matched healthy individuals. There was no association between the polymorphisms and the disease. There was no relation of the polymorphisms to the clinical variables, the thymic histopathologies, the level of serum acetylcholine receptor antibodies or the concentrations of IgG and its subclasses. Our data yield no evidence for the IL-6 gene contributing to the disease susceptibility.

The JNKK2-JNK1 fusion protein acts as a constitutively active c-Jun kinase that stimulates c-Jun transcription activity

c-Jun N-terminal protein kinase (JNK), a member of the mitogen-activated protein (MAP) kinase family, regulates gene expression in response to various extracellular stimuli. JNK is activated by JNK-activating kinase (JNKK1 and JNKK2), a subfamily of the dual specificity MAP kinase kinase (MEK) family, through phosphorylation on threonine (Thr) 183 and tyrosine (Tyr) 185 residues. The physiological functions of the JNK pathway, however, are not completely understood. A major obstacle is the lack of specific and activated kinase components that can stimulate the JNK pathway in the absence of any stimulus. Here we show that fusion of JNK1 to its upstream activator JNKK2 resulted in its constitutive activation. In HeLa cells, the JNKK2-JNK1 fusion protein showed significant JNK activity, which was comparable with that of JNK1 activated by many stimuli and activators, including EGF, TNF-alpha, anisomycin, UV irradiation, MEKK1, and small GTP binding proteins Rac1 and Cdc42Hs. Immunoblotting analysis indicated that JNK1 was phosphorylated by JNKK2 in the fusion protein on both Thr(183) and Tyr(185) residues. Like JNKK2, the JNKK2-JNK1 fusion protein was highly specific for the JNK pathway and did not activate either p38 or ERK2. Transient transfection assays demonstrated that the JNKK2-JNK1 fusion protein was sufficient to stimulate c-Jun transcriptional activity in the absence of any stimulus. Immunofluorescence analysis revealed that the JNKK2-JNK1 fusion protein was predominantly located in the nucleus of transfected HeLa cells. These results indicate that the JNKK2-JNK1 fusion protein is a constitutively active Jun kinase, which will facilitate the investigation of the physiological roles of the JNK pathway.

[The method of wavelet transformation used for extracting the characteristic of the exercise ECG]

This article introduces the basic rationale of wavelet transformation and the algorithm of typical dyadic wavelet transformation with mother wavelet of the first derivative of a Gaussian smoothing function, this wavelet transformation is used to recognize the characteristic parameters of the exercise ECG, it is concluded that this method make significant effects on restricting base line drifting and lessening noisy component in the exercise ECG, it provides a new way to do further research on characteristic recognition of the exercise ECG in the exercise test.

[Vroman effect of plasma protein adsorption to biomaterials surfaces]

Fibrinogen adsorption from plasma to biomaterials surfaces passes through a maximum when studied as a function of adsorption time, plasma concentration, or column height in narrow spaces and these are called Vroman effect. Studies have demonstrated that Vroman effect is a general phenomenon of plasma proteins and reflects the competitive adsorption of plasma proteins for a limited number of surface sites. In this paper, the factors affecting Vroman effect, the relationship between contact activation and fibrinogen displacement, and the significance of the Vroman effect with respect to blood-material interactions are reviewed.

Natural attenuation of BTEX compounds: model development and field-scale application

Benzene, toluene, ethyl benzene and xylene (BTEX) dissolved into ground water and migrated from a light nonaqueous phase liquid (LNAPL) source in a sandy aquifer near a petroleum, oil, and lubricants (POL) facility at Hill Air Force Base (AFB), Utah. Field observations indicated that microbially mediated BTEX degradation using multiple terminal electron-accepting processes including aerobic respiration, denitrification, Fe(III) reduction, sulfate reduction, and methanogenesis has occurred in the aquifer. To study the transport and transformation of dissolved BTEX compounds under natural conditions, a reactive flow and transport model incorporating biochemical multispecies interactions and BTEX was developed. The BTEX, oxygen, nitrate, Fe(II), sulfate, and methane plumes calculated by the model agree reasonably well with field observations. The first-order biodegradation rate constants, estimated based on model calibration are 0.051, 0.031, 0.005, 0.004, and 0.002 day(-1) for aerobic respiration, denitrification, Fe(III), sulfate reduction, and methanogenesis, respectively. The results of a sensitivity analysis show that the saturated aquifer thickness, hydraulic conductivity, and reaction rate constants are the most critical parameters controlling the natural attenuation of BTEX at this site. The hydraulic conductivity and aquifer thickness were found to be the key factors affecting the restoration of oxygen, nitrate, and sulfate after their interaction with the BTEX plume. The multispecies reactive transport modeling effort, describing BTEX degradation mediated by multiple electron-accepting processes, represents one of the few attempts to date to quantify a complete sequence of natural attenuation processes with a detailed field data set. Because the case study is representative of many petroleum-product contaminated sites, the results and insights obtained from this study are of general interest and relevance to other fuel-hydrocarbon natural attenuation sites.

[Multiresolution analysis based denoising algorithm for dynamic esophageal pH monitoring signal]

A denoising algorithm for dynamic esophageal pH monitoring signal is first introduced in this paper. The algorithm was developed on the basis of multiresolution analysis. The pH monitoring signal was investigated in experiments, then the algorithm was formulated by multiresolution analysis based on discrete dyadic wavelet transform combining with the results of the investigation mentioned above. Application of this algorithm to clinical data processing has proved its satisfactory denoising effect.

[Surgical treatment of gastric cancer in stage T1/T2: an reevaluation of the clinical significance of early gastric cancer]

OBJECTIVE

To evaluate the clinical significance of early gastric cancer by means of an analysis of the results of surgical treatment of gastric cancer in stage T1/T2.

METHODS

A retrospective review and survival analysis of 132 patients with stage T1/T2 stomach cancer treated from 1983 through 1993 was performed.

RESULTS

The average tumor size, lymph node involvement, postoperative recurrence and survival rate were significantly different between gastric cancer in stage T1 and T2. It was true of both groups of patients that the survival rate of patients with and without lymph node involvement was significantly different. However, the survival rate of patients in stage T2 but without lymph node involvement was not significantly different as compared to that of patients in stage T1.

CONCLUSION

For stage T1 stomach cancer, because of possible lymph node involvemnt, local mucosal excision of tumor is not recommended. For stage T2 stomach cancer without lymph node metastasis, it can be regarded as cancer still in its early stage when postoperative adjunct therapy is to be given.

[Endoscopic treatment of sphenoidal and ethmoidal mucoceles]

OBJECTIVE

To evaluate endoscopic surgery for sphenoidal and ethmoidal mucoceles.

METHOD

Seventeen patients diagnosed as having paranasal sinus mucoceles underwent attempted endoscopic marsupialization between 1989 and 1995. Ten of the mucoceles were in the sphenoid sinus, seven in the ethmoid sinus. Postoperative endoscopic follow-up period varied from 3 to 9 years.

RESULT

All the sphenoidal and ethmoidal mucoceles were satisfactorily approached endoscopically. Postoperative endoscopic examination manifested all the operating cavity was satisfactorily marsupialized. The symptoms were improved or relieved in 15 patients. None of the patients undergoing endoscopic surgery had significant complications.

CONCLUSION

Our results show that endoscopic surgery seems to be a safe, valuable way for management of sphenoidal and ethmoidal mucoceles.

[Usefulness of CYFRA21-1 as a tumor marker of non-small-cell lung cancer]

OBJECTIVE

To evaluate the clinical usefulness of CYFRA21-1 as a serum tumor marker in diagnosis, evaluation of clinical status and prognosis of patients with non-small-cell lung cancer (NSCLC).

METHODS

CYFRA21-1 in 126 serum samples of NSCLC patients was measured by radioimmunoassay. Of the 126 samples, 71 were collected before treatment, 29 at two weeks after operation, and 26 after 15-18 months follow-up.

RESULTS

CYFRA21-1 was positive in 49.3% of the NSCLC patients who had not received any treatment. The positive rate was 69.2% for squamous-cell carcinoma, and 25.0% for adenocarcinoma. The serum level of CYFRA21-1 was significantly higher in squamous-cell carcinoma than in adenocarcinoma (P < 0.0001). The serum level of CYFRA21-1 well correlated and increased with TNM staging (P = 0.0001). The level decreased significantly within two weeks after surgical operation in 29 cases (P = 0.0005). On follow up for 15-18 months, no change in CYFRA21-1 level was observed in 16 patients whose disease was stable, while there was significant increase in 10 patients with progressive disease.

CONCLUSION

CYFRA21-1 is a soluble fragment of cytokeratin 19 in serum of patients with NSCLC. It can be used as a useful tumor marker of NSCLC.

[The basic study of noninvasive detecting the ischemic/hypoxic cerebral injury]

The cerebrovacular diseases are important causes of mortality and disability in the world, and with the development of science and technology, many mission-oriented basic researches are aimed at the ischemic/hypoxic brain injury. This paper introduces some progress made in our research in this field, which includes: the animal experiment model of brain injury; the technique to efficiently extract evoked potentials from electroencephalogram; and the identification of the characteristic information of brain injury.

Effect of clodronate on macrophage depletion and adenoviral-mediated transgene expression in salivary glands

Expression of transgenes from adenoviral vectors is short-lived in salivary glands, in part because of immune responses to the virus and/or transgene product. Previous studies demonstrated that depletion of macrophages with multilamellar liposomes containing clodronate (Cl2MBP) increases adenoviral-mediated transgene expression in the liver. This technique was tested in salivary glands. Rats were treated with Cl2MBP-liposomes or control liposomes by femoral vein, intraperitoneal, or carotid artery injections. Thereafter, a recombinant adenovirus, AdCMVluciferase, was instilled intraductally in submandibular glands (SMGs), or delivered to the liver via femoral vein injection. Marked depletion (>94%) of liver macrophages and increased levels of luciferase activity in the liver (45-fold higher than controls) were present in animals receiving Cl2MBP-liposomes. In contrast, the same treatment never depleted more than 41% of SMG macrophages nor increased luciferase activity in SMGs, regardless of the route of administration. In conclusion, while macrophage depletion with Cl2MBP-liposomes is associated with markedly increased adenoviral-mediated transgene expression, this strategy was ineffective for salivary glands.

Structural basis of neurophysin hormone specificity: Geometry, polarity, and polarizability in aromatic ring interactions

The structural origins of the specificity of the neurophysin hormone-binding site for an aromatic residue in peptide position 2 were explored by analyzing the binding of a series of peptides in the context of the crystal structure of liganded neurophysin. A new modeling method for describing the van der Waals surface of binding sites assisted in the analysis. Particular attention was paid to the unusually large (5 kcal/mol) difference in binding free energy between Phe and Leu in position 2, a value representing more than three times the maximum expected based on hydrophobicity alone, and additionally remarkable since modeling indicated that the Leu side chain was readily accommodated by the binding pocket. Although evidence was obtained of a weak thermodynamic linkage between the binding interactions of the residue 2 side chain and of the peptide alpha-amino group, two factors are considered central. (1) The bound Leu side chain can establish only one-third of the van der Waals contacts available to a Phe side chain. (2) The bound Phe side chain appears to be additionally stabilized relative to Leu by more favorable dipole and induced dipole interactions with nonaromatic polar and sulfur ligands in the binding pocket, as evidenced by examination of its interactions in the pocket, analysis of the detailed energetics of transfer of Phe and Leu side chains from water to other phases, and comparison with thermodynamic and structural data for the binding of residue 1 side chains in this system. While such polar interactions of aromatic rings have been previously observed, the present results suggest their potential for significant thermodynamic contributions to protein structure and ligand recognition.

Identification of T-DNA tagged Arabidopsis mutants that are resistant to transformation by Agrobacterium

We have identified T-DNA tagged Arabidopsis mutants that are resistant to transformation by Agrobacterium tumefaciens (rat mutants). These mutants are highly recalcitrant to the induction of both crown gall tumors and phosphinothricin-resistant calli. The results of transient GUS (beta-glucuronidase) assays suggest that some of these mutants are blocked at an early step in the Agrobacterium-mediated transformation process, whereas others are blocked at a step subsequent to translocation of T-DNA into the nucleus. Attachment of Agrobacterium to roots of the mutants rat1 and rat3 was decreased under various incubation conditions. In most mutants, the transformation-deficient phenotype co-segregated with the kanamycin resistance encoded by the mutagenizing T-DNA. In crosses with susceptible wild-type plants, the resistance phenotype of many of these mutants segregated either as a semi-dominant or dominant trait.

[Using complexity measurement to study the EEG signal of focal ischemic cerebral injury]

In this paper, a model for SD rat focal ischemic cerebral injury is presented. Based on this experiment model, we recorded the EEG of ischemic region and normal region from before ischemia to after ischemia 30 minutes. We analyzed the complexity of these EEG signals, and found that the EEG complexity was very sensitive to focal ischemic cerebral injury. The EEG complexity on ischemic region was less than that on normal region. The difference in EEG complexity between two regions increased with the decreasing velocity. When insult took place, the EEG complexity was less than that before ischemai. These resluts agree to those we obtained by Discrete Gabor Spectrogram analysis and Heat Shock Protein (HSP) expression. The ischemic and normal regions can be clearly distinguished by analyzing their EEG complexity, and the extent can also be detected in this way.

[The characteristic wave intervals of exercise ECG influenced by changing of heart rate]

This paper analyzes the characteristic wave intervals of exercise ECG influenced by heart rate changing under exercise test. The most influenced parameter is TP interval, the next is QT interval, and the width of P wave and QRS waves are nearly unchanging. According to the changing characteristic of these waves width mentioned above, we suggest an adaptive adjusting method for ST segment measuring position after the J point, which is of significance to recognizing the characteristic waves and determining the result of exercise test for myocardial ischemia.

Adenovirus-mediated TNF-alpha gene transfer induces significant tumor regression in mice

Recombinant adenovirus vectors are highly efficient at in vitro and in vivo gene delivery. The in vitro infection of a mouse colon adenocarcinoma cell line MCA-26 with the adenovirus AdV-LacZ can reach a maximal 75% of infectivity at an MOI of 1000. Intratumoral injection of AdV-LacZ (2X10(9) pfu) resulted in substantial gene transfer in nearly 70% of MCA-26 tumors. After the in vitro infection of AdV-TNF-alpha, infected MCA-26 cells showed significant secretion of TNF-alpha (45 ng/ml/10(6) cells) in tissue culture. The secretion peaks at day 2 and is diminished at day 4 following the viral infection. Infected MCA-26 tumor cells secreting TNF-alpha significantly reduced their tumorigenicity in syngeneic BALB/c mice. In mice bearing small tumors, intratumoral injection of 2X10(9) pfu of AdV-TNF-alpha virus with a repeated booster treatment resulted in complete regression of three tumors and significant diminution of the other two with a mean tumor-weight of 0.16 g; this is in contrast to 0.85 and 1.62 g for tumors injected with the control AdV-pLpA and PBS respectively (p < 0.01). Mice with complete tumor regression further developed protective immunity against the second challenge of MCA-26 inoculation. In mice bearing large tumors, this treatment also caused significant inhibition of tumor growth with a mean tumor weight of 0.65 g vis-a-vis 3.05 g for tumors injected with the control AdV-pLpA. On the contrary, in mice bearing large tumors, the treatment of tumors with pCI-TNF-alpha delivered by the gene gun did not induce significant tumor inhibition. These results indicate that the adenoviral delivery of TNF-alpha gene is more efficient than the particle-mediated gene gun device, and that adenovirus-mediated cytokine gene therapy may be a useful approach in the clinical management of human solid tumors.

The Mycobacterium tuberculosis small heat shock protein Hsp16.3 exposes hydrophobic surfaces at mild conditions: conformational flexibility and molecular chaperone activity

Hsp16.3, the alpha-crystallin-related small heat shock protein of Mycobacterium tuberculosis that is maximally expressed during the stationary phase and is a major membrane protein, has been reported to form specific trimer-of-trimers structure and to act as an effective molecular chaperone (Chang Z et al., 1996, J. Biol Chem 271:7218-7223). However, little is known about its action mechanism. In this study, Hsp16.3 conformational intermediates with dramatically increased chaperone activities were detected after treatment with very low concentrations of guanidine hydrochloride (0.05 M), urea (0.3 M), or mild heating (30 degrees C). The intermediates showed a significant increase in their capacity to bind the hydrophobic probe 1-anilino-8-naphthalene sulfonate (ANS), indicating an increased exposure of hydrophobic surfaces. Interestingly, the greatest chaperone activities of Hsp16.3 were observed in the presence of 0.3 M guanidine HCl or when heated to 35 degrees C. CD spectroscopy studies revealed no significant changes in protein secondary and tertiary structures at these mild treatments. Our in vitro studies also indicate that long-time-heated Hsp16.3, heated even to temperatures as high as 85 degrees C, has almost the same, if not a slightly greater, chaperone activities as the native protein when cooled to room temperature and its secondary structures also almost recovered. Together, these results suggest that Hsp16.3 modulates its chaperone activity by exposing hydrophobic surfaces and that the protein structure is highly stable and flexible, thus highly adapted for its function.

[Cytogenetic study in eight cases of Fanconi anemia]

OBJECTIVE

To study the clinical, hematological and cytogenetical characteristics in Fanconi anemia (FA).

METHODS

Culture the peripheral lymphocytes with Mitomycin C (MMC) induction to count the chromosome breakages and to count the sister chromatid exchanges (SCE) in FA.

RESULTS

The clinical and hematological manifestations in FA varied at all. Spontaneous chromosome break and MMC induced break in FA were significantly higher than those in normal. Spontaneous and induced SCE were also higher in FA.

CONCLUSION

Owing to genetic heterogeneity in FA, the phenotypes in FA are diversified also. So, chromosome breakage study is a very important method in the diagnosis of FA, and gene complementation analysis may identify which complementation group the patient carries.

Bletilla striata as a vascular embolizing agent in interventional treatment of primary hepatic carcinoma

OBJECTIVE

To evaluate Bletilla striata as a vascular embolizing agent in interventional treatment of primary hepatic carcinoma.

METHODS

We made a vascular embolizing agent from a Chinese medicinal herb, Bletilla striata (bai ji). From October 1991 to January 1995, 56 patients with primary hepatic carcinoma were treated by hepatic arterial chemoembolization with Bletilla striata angioembolus, and 50 patients with primary hepatic carcinoma who were treated by conventional gelfoam embolization served as controls. All patients were followed up for 10-48 months.

RESULTS

Embolization with the Bletilla striata powder produced extensive and permanent vascular obstruction, resulting in marked shrinkage of the tumor and significant decrease of serum alpha fetoprotein (AFP) level. After embolization, less collateral circulation formed later. The treatment interval was prolonged to an average of 7 months. The 1-, 2- and 3-year survival rates were 81.9%, 44.9%, and 33.6%, respectively, with a mean survival period of 19.8 months. All the clinical parameters were better than those in the control group treated by conventional gelfoam embolization.

CONCLUSION

Bletilla striata angioembolus is a good vascular embolizing agent for treating PHC.

Growth factor regulation of the amylase promoter in a differentiating salivary acinar cell line

Salivary glands contain two major epithelial cell types: acinar cells which produce the primary salivary secretion, including amylase, and ductal cells which reabsorb electrolytes but also secrete kallikrein. Here we investigated salivary acinar cell differentiation in vitro using the activity of the salivary amylase and tissue kallikrein promoters as markers of acinar cell and ductal cell differentiation, respectively. Each of the promoter sequences was cloned into a replication-deficient adenoviral vector containing the luciferase reporter gene. Previous studies showed that a human submandibular gland cell line (HSG) differentiated into acinar cells when cultured on a reconstituted basement membrane matrix (Matrigel). The luciferase activity of the amylase promoter vector (AdAMY-luc) was low in HSG cells cultured on plastic, where they grow as an epithelial monolayer. The promoter activity increased approximately tenfold when HSG cells were cultured on Matrigel and developed an acinar phenotype. Under the same conditions, the luciferase activity of the kallikrein promoter (AdKALL-luc) was not induced. Because HSG cells demonstrate acinar cell morphology, but not amylase gene expression, when cultured on laminin-1, certain soluble components of Matrigel were tested for their ability to induce the amylase promoter during in vitro differentiation of acinar cells. We find that epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), which are present in the basement membrane, and hepatocyte growth factor (HGF) increase activity of the amylase promoter. Other basement membrane-derived growth factors such as TGF-beta, basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PGDF), as well as tumor necrosis factor (TNF-alpha), keratinocyte growth factor (KGH), nerve growth factor (NGF) and interferon gamma (IFN-gamma) were inactive. This system will be further exploited to study the mechanisms by which extracellular matrix molecules and growth factors regulate salivary acinar cell differentiation.

[An automatic method segmenting lung regions from digital chest radiograph]

It is difficult to process digital chest image with ordinary method because of the wide dynamic range of chest radiograph. Anatomically adaptive processing is a better method for chest image, but it needs automatic segmentation of the image. In this paper, an effective method for segmenting lung regions from digital chest radiograph is presented. This method automatically calculates the lung/mediastinum-subdiaphragmatic threshold according to the histogram of chest image processed.

[Self-organization neural network based ultrasonic heart image segmentation]

Segmentation is one of the most difficult problems in multidimensional reconstruction of ultrasonic heart image. In the present paper, a segmentation method of ultrasonic heart image using the self-organization neural network has been studied. This is an unsupervised segmentation method, which can segment images through clustering automatically. The results show that the present method has significant benefits over the traditional K-means algorithm.

[Photothermal deflection spectroscopy for the detection of fluoride ion content in water]

In this paper the application of photothermal deflection spectroscopy to the detection of fluoride ion content in water is described. This PDS method gets rid of two factors that impair the test sensitivity of regular photometric method applied to the measurement of solution concentration, and increases the sensitivity. That the PDS signal varied with modulation frequencies, pump laser powers and probe laser powers is discussed, and the appropriate parameters of test apparatus are chosen.

[Relationship between endothelin-1 and ischemic brain damage after subarachnoid hemorrhage and protective effect of Ginkgo biloba extract]

OBJECTIVE

To investigate the role of endothelin-1 (ET-1) in development of ischemic brain damage after subarachnoid hemorrhage (SAH), and the protective effect of Ginkgo biloba extract (GBE).

METHODS

Wistar rat noncraniotomy models of SAH were divided into SAH group and GBE treated group, the diameter of basilar artery (BA) and dynamic changes of regional cerebral blood flow (rCBF) and ET-1 content of intracranial plasma within 24 hours after SAH of both groups were determined. And pathological examination of CA1 region of hippocampus was performed 3 days later.

RESULTS

rCBF decreased and ET-1 content increased obviously and retained in 24 hours after SAH. Spasm of BA occurred half an hour after SAH and neurons of hippocampus CA1 region was damaged severely. GBE could antagonize the above-mentioned pathological changes effectively.

CONCLUSION

Increase of ET-1 is an important factor leading to ischemic brain damage after SAH. GBE exerts its protective effect by antagonizing pathological increase of ET-1.

[Doppler echocardiographic studies on fetal cardiac function of diabetic mothers]

OBJECTIVE

To assess fetal cardiac function by Doppler echocardiography in diabetic pregnancies.

METHODS

We investigated the changes of cardiac function in 54 normal fetuses and 23 fetuses of diabetic mothers. Cardiac anatomic datas were obtained by measuring the diameter of the aortic (AO), the pulmonary artery (PA), the mitral valve(MV), the tricuspid valve (TV) and interventricular septal thickness (IVS). Blood flow evlocity were obtained from the AO, PA, atrioventricular valves. The following variables were measured: peak flow velocity (PFV), accelerate time (ACT), systolic volume (SV) and ForceF. These indices respresented the systolic function. The peak early flow velocity (PFVe), peak late flow velocity (PFVa), PFVe/PFVa(E/A), mean velocity (V) of MV or TV respresented the diastolic function.

RESULTS

The results revealed that in fetuses of diabetic mothers, IVS became thickness. The diameter of AO, PA, MV, TV were wider than that of normal fetases. The PFV, SV, ForceF of AO or PA increased significantly. There was no different in ACT between two groups. The PFVa of MV or TV increased significantly, whereas the E/A of both atrioventricular valves decreased.

CONCLUSION

It showed that the fetal hyperinsulinemia triggered by maternal hyperglycemia result in fetal weight increasing, as well as hyperplasia and hypertrophy of myocardial cells. An iacreased contractility is compatible with relatively larger size of such fetuses. The intracardiac flow volume increased secondary to the more needs of fetal development. Abnormal thickenning IVS might impair ventricular diastolic function.

Gamma-irradiation-induced cell cycle arrest and cell death in a human submandibular gland cell line: effect of E2F1 expression

This study examined the effect of gamma-irradiation (5 and 10 Gy) on the human submandibular cell line (HSG). Radiation treatment (5 Gy and 10 Gy) induced a dose-dependent decrease in cell proliferation, with a G2/M arrest of the cell cycle, and an increase in cell death (cells with <2n DNA increased from 7% in control cells to 34% and 40% in 5 and 10 Gy irradiated cells, respectively). [Ca2+]i measurements demonstrated that the status of internal Ca2+ stores, and muscarinic receptor-mediated Ca2+ mobilization, in irradiated cells was comparable to that in non-irradiated cells. These data suggest that 1) irradiated HSG cells maintain normal physiology and 2) internal Ca2+ store depletion does not account for the decreased cell proliferation. To manipulate the radiation-induced cell cycle arrest, we examined the effect of the transcription factor E2F1, which has been shown to induce cell cycle progression in HSG cells (Lillibridge and O'Connell, 1997, J. Cell. Physiol., 1 72:343-350). The ability of irradiated HSG cells to express and appropriately route proteins was demonstrated by using adenovirus-mediated expression of beta-galactosidase, alpha1-antitrypsin, and aquaporin-1. Infection of HSG cells with an adenoviral vector encoding E2F1, either 12 h before or immediately following irradiation, but not post-irradiation, induced maintenance of cells in the S phase of the cell cycle, reduced the number of cells arrested at G2/M, and decreased the rate of appearance of cells with <2n DNA. While the mechanism of irradiation-induced cell death has not yet been confirmed, these data suggest that expression of the E2F1 gene product in HSG cells can be a useful strategy to manipulate cell cycle events and reduce the initial loss of cells due to radiation.

Intratumoral vaccination of adenoviruses expressing fusion protein RM4/tumor necrosis factor (TNF)-alpha induces significant tumor regression

Recombinant adenovirus (AdV) vectors are highly efficient at in vitro and in vivo gene delivery. VKCK is a murine myeloma cell line expressing the light chain of the fusion protein RM4/tumor necrosis factor (TNF)-alpha. The in vitro transfection of VKCK cells with the AdV AdV5LacZ, which contains the marker gene beta-galactosidase, can reach a maximal 75% at a multiplicity of infection of 1000. Intratumoral injections of AdV5LacZ (2 x 10(9) plaque-forming units) resulted in substantial gene transfer in nearly 50% of VKCK tumors. The AdV pLpA/M4-TNF-alpha, which contains a fused gene M4-TNF-alpha that codes for the heavy chain of fusion protein RM4/TNF-alpha, was constructed. After the in vitro transfection of pLpA/M4-TNF-alpha at a multiplicity of infection of 1000, transfected VKCK cells showed significant secretion of RM4/TNF-alpha (36 ng/mL/10(6) cells) containing the functional TNF-alpha moiety in tissue culture. The secretion peaks at day 3 and is diminished at day 6 following the viral infection. These transfected VKCK cells also became more immunogenic with enhanced expression of major histocompatibility complex class I antigen. Intratumoral injections of 2 x 10(9) plaque-forming units of pLpA/M4-TNF-alpha virus with a repeated booster resulted in significant VKCK tumor regression in immune-competent mice, but not in athymic nude mice with a mean tumor weight of 0.07 g that were compared with 1.58 g and 1.70 g for tumors injected with AdV5LacZ and phosphate-buffered saline, respectively (P < .01). The tumor regression also results in protective immunity against a second challenge with parental tumor cells, which is mainly mediated by VKCK tumor-specific CD8+ T cells. These results indicate that AdV-mediated cytokine gene therapy may be a useful approach in the clinical management of solid human tumors.

Differential stimulation of proline-rich tyrosine kinase 2 and mitogen-activated protein kinase by sphingosine 1-phosphate

Sphingosine 1-phosphate (SphP), a metabolite of cellular sphingolipids, has been shown to induce cell proliferation by activating the mitogen-activated protein kinase (MAPK) pathway. Proline-rich tyrosine kinase 2 (Pyk2) is a novel cytosolic tyrosine kinase which mediates activation of the MAPK or c-Jun N-terminal kinase (JNK) signaling pathways in response to a variety of stimuli that elevate intracellular calcium. In this report, we show that SphP stimulates both tyrosine phosphorylation of Pyk2 and MAPK activation in a transient and dose-dependent manner in rat aortic smooth muscle cells. Further studies indicate that Pyk2 phosphorylation, but not MAPK activation, is dependent on a pertussis toxin-sensitive G-protein-coupled receptor as well as partially on actin cytoskeleton. In addition, both intracellular calcium mobilization and protein kinase C (PKC) are required for optimal Pyk2 phosphorylation while either calcium increase or PKC activation is sufficient for MAPK activation in response to SphP. Finally, we show that a tyrosine kinase(s) other than Pyk2 is necessary for MAPK activation by SphP. Together, these results suggest that SphP stimulates tyrosine phosphorylation of Pyk2 through a G-protein coupled receptor, which is dissociated from its activation of the MAPK pathway in these cells.

[Assessment of diagnostic result for medical image by receiver operating characteristic and forced choice]

Two methods for diagnostic image evaluation, the receiver operating characteristic (ROC) and the forced choice, are introduced in this paper. The concepts of ROC and forced choice are described firstly, then the experiment design consideration and data analysis are discussed.

[Development of new ambulatory monitor for multi-channel gastroesophageal pH combining with cardiogram]

A new ambulatory monitor for multi-channel gastroesophageal pH combining with cardiogram is introduced in this paper. Key techniques of the monitor, design of hardware and software, clinical significance are described. Clinical application shows that the monitor advantages the diagnoses of functional diseases of upper digestive tract, especially is significant to distinguish the chest pain of cardiac origin and esophageal origin.

In vivo use of adenoviral vectors: effects on salivary gland structure

Recently there has been considerable progress in the development of in vivo gene transfer technology. By this means, new genetic information may be introduced directly to cells, while the cells remain in their natural milieu. The ability to express exogenous proteins makes it possible to explore the functions of native or altered proteins and thereby develop new insights into cell function and dysfunction. We have demonstrated that the major salivary glands are efficiently infected by recombinant adenovirus vectors. These vectors are capable of expressing transgenes in both acinar and ductal cell types. Recently, we have developed vectors that contain cell-specific promoters so that proteins may be expressed in selected subpopulations of salivary cells. Early generations of adenoviral vectors elicited potent immune responses in vivo. However, modified vectors and adjunctive measures have improved the safety of gene transfer to salivary glands. Future studies will aim to increase the duration of adenovirus-based gene expression and to produce vector systems that are not toxic to the host.

[The time-frequency analysis of the exercise ECG signal]

Exercise ECG indicates information about the heart load status in the exercise test. It is very significant to represent the characteristics of the exercise ECG for evaluating the exercise load test. This article introduces the principle of Winger-Ville Distribution time-frequency analysis and its implementation. By applying this method to analyse exercise ECG, some results were acquired. It is a promising method to do research of the exercise ECG in the time-frequency plane.

[Pressure control system for the hermetically sealed cabin of the recoverable satellite]

There are many precision instruments and equipment for scientific researches and experiments in the hermetically sealed cabin of satellite. Appropriate pressure must be controlled in the cabin in order to ensure the instruments and equipment from the adverse space environment. This paper describes a pressure control system for the hermetically sealed cabin in the recoverable scientific detect and experimental satellite. The cabin pressure is regulated automatically into the specific levels by venting or supplying the air from or to the cabin during launch, on orbit and before reentry of the satellite. The system has low mass, low power consumption and high reliability. It was used successfully in the recoverable satellite first in September 1987 and had been used many times since then. It is the first active pressure control system for the hermetically sealed cabin of the satellite in China.

[A micro transducer for dynamic multi-location pH monitoring in upper digestive tract]

A new transducer catheter used for dynamic multi-location pH monitoring in upper digestive tract has been developed. On the catheter several antimony electrodes and an Ag-Agcl electrode are integreted. An animal experiment compared the results of gastric aspiration and dynamic recording and demonstrated the reliability of this transducer. Clinical application has shown that this technology contributes greatly to the research on digestive physiology and to the diagnosis of functional diseases such as non-cardiac chest pain.

[Coexisting pheochromocytoma and renal artery stenosis]

OBJECTIVE

To improve the diagnosis of coexisting pheochromocytoma and renal artery stenosis.

METHOD

Four patients with coexisting pheochromocytoma and renal artery stenosis were treated.

RESULT

After removal of the pheochromocytoma, the blood pressure became normal in two patients combined with resection of kidney with renal artery stenosis, and one patient with local adhesion loosened. The hypertension, however, persisted in another patient after the resection of pheochromocytoma even though the long segment of renal artery stenosis was relieved.

CONCLUSION

After pheochromocytoma was diagnosed with its known position, coexisting renal artery stenosis should be suspected according to one of the following conditions: (1) Vascular murmurs are noted at the area of the upper abdomen or back; (2) One of the kidneys becomes less sized; (3) Using the inhibitor of receptor alpha only has no effect lowering blood pressure and it is necessary to add the inhibitor of angiotension; (4) Postoperative hypertension does not resolve when no remaining pheochromocytoma is present. the renal artery stenosis can be reversed after both removal of pheochromocytoma and loosening of adhesion in case of stenosis due to the pressure of the tumor and adhesion caused renal artery angling and local stricture. Extensive stenosis or closure, however, can not be corrected with severe atrophy of renal parenchyma due to pheochromocytoma, and the resection of kidney should be indicated.

[Bispectral analysis of EEG signal during focal cerebral ischemia]

Early noninvasive detection of cerebral ischemia is important for fighter pilots as well as in clinical diagnosis. In this paper, a model of focal cerebral ischemia was presented. Bispectrum of EEG signals recorded from ischemic region and normal region after 30 min ischemia was analyzed using the third-order recursion method, which possesses higher frequency resolving ability. It can resolve two closely spaced peaks in the bispectrum and detect the presence or absence of quadratic phase coupling at frequency pairs that are very close to each other. It was found that some characteristics of such bispectrum are very sensitive to focal cerebral ischemia. The maximum bispectrum magnitude of EEG and the weighted center of bispectrum (WCOB) changed sensitively to the different ischemic regions and ischemic stages. The ischemic and normal regions as well as the degree of ischemia can be clearly distinguished by analyzing their bispectrum of EEG. It demonstrates that this method can be used as a quantitative method for the detection of focal cerebral ischemia in the early phase.

[Studies on trigonometric transform enhancement of chest radiograph based on its anatomical feature]

In this paper, we present a novel trigonometric transform contrast enhancement method for digital chest radiograph, which is based on the anatomical feature of the image processed. With automatic segmenting chest image into a lung region and a non-chest region, a positive linear transform and a negative one are used in lung region and the other region respectively. Therefore, it can enhance the contrast both in lung regions and in mediastinum region up to entire dynamic range of display device.

A polarized salivary cell monolayer useful for studying transepithelial fluid movement in vitro

There are no reported, convenient in vitro models for studying polarized functions in salivary epithelial cells. Accordingly, we examined three often-used salivary cell lines for their ability to form a polarized monolayer on permeable, collagen-coated polycarbonate filters. Only the SMIE line, derived from rat submandibular gland, had this ability. The SMIE cell monolayer exhibited junctional complexes, with a tight-junction-associated protein, ZO-1, localized to cell-cell contact areas. The Na+/K+-ATPase alpha1-subunit was detected predominantly in the basolateral membranes, while the Na+/H+ exchanger isoform 2 appeared primarily in the apical membranes. Using adenovirus-mediated cDNA transfer, SMIE cells were shown to be capable of routing marker proteins (beta-galactosidase +/- a nuclear targeting signal, alpha1-antitrypsin, aquaporin-1) to appropriate locations. Furthermore, this salivary cell monolayer provided a convenient tool for studying aquaporin-1-mediated, osmotically directed, transepithelial fluid movement in vitro. Thus, SMIE cells appear to be a useful experimental model with which to study some polarized functions in a salivary epithelial cell line.

Differential regulation of Pyk2 and focal adhesion kinase (FAK). The C-terminal domain of FAK confers response to cell adhesion

Pyk2 is a recently described cytoplasmic tyrosine kinase that is related to focal adhesion kinase (FAK) and can be activated by a variety of stimuli that elevate intracellular calcium. In this report, we showed that Pyk2 and FAK tyrosine phosphorylation are regulated differentially by integrin-mediated cell adhesion and soluble factors both in rat aortic smooth muscle cells, which express endogenous Pyk2 and FAK, and in transfected Chinese hamster ovary cells. We also found that Pyk2 is diffusely present throughout the cytoplasm, while FAK is localized in focal contacts as expected, suggesting that the different localization may account for their differential regulation. By analyzing a chimeric protein contain N-terminal and kinase domains of Pyk2 and C-terminal domain of FAK, we provided evidence that the distinctive C-terminal domains of Pyk2 and FAK were responsible for their differential regulation by integrins and soluble stimuli as well as their subcellular localization. Finally, we correlated FAK, Pyk2, and the chimeric protein binding to talin, but not paxillin, with their regulation by integrins and focal contact localization. These results demonstrate that the distinctive C-terminal domain of Pyk2 and FAK confer their differential regulation by different subcellular localization and association with the cytoskeletal protein talin.

Renal angiomyolipoma: diagnosis with B-ultrasonography, CT scanning, DSA and its interventional treatment

From 1989, 15 cases of renal angiomyolipoma (AML) have been diagnosed by ultrasonography. CT scanning and digital subtraction angiography (DSA) at our hospital. In 8 patients with uneven hyperechoes on B-mode ultrasonography (B-US) (8/15) and 7 with low density of fat on CT scanning (7/12) accurate diagnosis was established preoperatively. DSA revealed the "berry-like" pseudoaneurysms in the arterial phase (14 cases), the defined lucent area in the nephrogram phase (10 cases) and the "onion-peel appearances" during venous phases (8 cases), correct diagnosis was achieved in all patients. 8 cases were surgically treated and 7 treated by subselective embolization of renal artery. Effects in all cases were good. The diagnostic value of B-US, CT scanning, DSA and interventional treatment of AML was discussed. It was believed that the diagnosis with DSA was a technique with high specificity, and embolization therapy was simple and effective for AML.

[Doppler echocardiographic studies on the fetal cardiac function in intrauterine growth retardation]

OBJECTIVE

To assess fetal cardiac function by Doppler echocardiography in intrauterine growth retardation (IUGR).

METHODS

We investigated the changes in cardiac function in 64 normal fetuses and 36 fetuses with IUGR. Blood flow velocity waveforms were obtained from the aorta, pulmonary artery and atrioventricular valves. The following variables were measured: peak flow velocity (PFV), mean velocity (V), accelerate time (ACT), systolic volume (SV) and cardiac output (CO) represented the systolic function; the peak early flow velocity (PFVe), peak late flow velocity (PFVa), PFVe/PFVa (E/A), mean velocity (V) of mitral or tricuspid valve represented the diastolic function.

RESULTS

In normal fetuses, the PFV, V, ACT of aorta were all greater than those of pulmonary artery, whereas SV, CO in left ventricle were smaller. The PFVe, PFVa in mitral valve were smaller than those of tricuspid valve. In IUGR fetuses, the PFV, V, SV, CO of aorta or pulmonary artery were significantly lower than those of normal. The ACT in pulmonary artery decreased significantly, but increased in aortic artery. The SV, Co of left ventricle were greater than those of righ ventricle. The E/A of mitral and tricuspid valve, PFVe, PFVa, V of tricuspid valve were all decreased. The PFVe, PFVa in mitral valve were greater than those of tricuspid valve.

CONCLUSIONS

The changes of cardiac function in IUGR are probably caused by "brain sparing", which means a redistribution of cardiac flow after hypoxia.

[Comparative study on the long-term effect of permanent embolization of hepatic artery with Bletilla striata in patients with primary liver cancer]

From May, 1990 to Sept., 1993 106 cases of primary liver cancer were treated by temporary or permanent hepatic arterial embolization with Bletilla striata powders (permanent, 56 cases) or gelfoam powders (temporary, 50 cases) under controlled technical conditions, in term of degree of tumor necrosis, revascularization of tumor, and long-term effect, the results of Bletilla striata group were better as compared with those of gelfoam group. The 1, 2 and 3 year survival rates were 44.9%, 33.6% and 33.6% in Beltilla striata group while the rates were 48.9%, 31.1% and 16.0% in gelfoam group, suggesting that Bletilla striata is superior to gelfoam as an embolizing agent for hepatic carcinoma.

[Pharmacognostical identification of Anoectochilus roxburghii]

This paper reported the pharmacognostical identification on characters, microscopic characteristics and TLC of the Anoectochilus roxburghii (Wall.) Lindl., and compared with different resouce samples. The results may provide reference for its identification.

[An experimental study on regeneration device for urine and waste water in space station]

The principle, structure and function of the regeneration system for urine and waste water treatment were introduced. The experimental results demonstrated that, the treatment capacity was 1.2-1.9 kg/h, and the regeneration efficiency exceeded 92%. The quality of the treated water were: TOC < 20 g/m3, (NH3 + NH4+) < 10 g/m3, electric conductivity < 100 micro s/cm, pH= 6-8.

Modulation of dimerization by residues distant from the interface in bovine neurophysin-II

The crystal structure of bovine neurophysin-II in its liganded state (Chen et al. [1991] Proc. Natl. Acad. Sci. USA 88, 4240-4244) indicates that the 1-6 sequence has a disordered conformation, lacks noncovalent contacts to other regions of the protein and is distant from the monomer-monomer interface. Cleavage of the 1-6 sequence by Staphylococcus protease V8 yielded a protein that, for the first time, crystallized in both liganded and unliganded states. Insights into the role of the 1-6 sequence in the unliganded state were obtained by NMR and related biophysical comparisons of the native and des-1-6 proteins. NMR spectra demonstrated that the environment and/or conformation of residues in the 1-6 sequence differed in liganded and unliganded states. Additionally, the unliganded des-1-6 protein exhibited a dimerization constant four to five times that of the native protein, potentially accounting for the observation that its peptide affinity was also increased. NMR studies further indicated that the increased dimerization constant of the des-1-6 protein correlated with the presence in the native protein of two isoenergetic forms of the monomer, in contrast to only a single form in the des-1-6 protein, as evidenced by signals from an internal dimerization-sensitive alpha-proton. Thus, the 1-6 sequence reduces the dimerization constant by stabilization of an alternative monomer conformation. A second product of Staphylococcus protease V8 digestion of the native protein was identified as the des-1-6 protein with an internal clip after binding site residue Glu-47, the clip presumably breaking the short 3,10 helix that most directly connects the interface to the interface to the binding site. This product, although unable to bind peptide, retained the dimerization constant of the des-1-6 protein, suggesting a lack of importance of the helix in dimerization and contrasting with the effects of the 1-6 sequence. A model is proposed in which the 1-6 sequence stabilizes the second conformation of the unliganded monomer via interactions affecting the loop region that separates the two neurophysin domains and which has been shown to influence neurophysin self-association.