[Research on the oncogenesis of cervical epithelial cells co-induced by human papillomavirus and human cytomegalovirus]

OBJECTIVE

The carcinogenesis of the human cervical carcinoma is known closely associated with human papillomavirus (HPV). The purpose of this article is to identify whether another sexually transmitted factor, human cytomegalovirus (HCMV) plays as a co-factor role in the carcinogenesis.

METHODS

Human cervical epithelial cells immortalized by HPV16 were transfected with IE gene of HCMV. The condition and efficiency of IE gene were examined.

RESULTS

It was showed that the cervical epithelial cells could be completely transformed into malignant by HPV 16 and IE gene of HCMV and tumor was formed by injecting the transformed cells in nude mice.

CONCLUSION

The co-operation effect of HPV and HCMV auailed the oncogenesis of human cervical carcinoma and moreover, the cellular and molecular biological mechanism was discussed.

Subset-based training and pruning of sigmoid neural networks

In the present paper we develop two algorithms, subset-based training (SBT) and subset-based training and pruning (SBTP), using the fact that the Jacobian matrices in sigmoid network training problems are usually rank deficient. The weight vectors are divided into two parts during training, according to the Jacobian rank sizes. Both SBT and SBTP are trust-region methods. Compared with the standard Levenberg-Marquardt (LM) method, these two algorithms can achieve similar convergence properties as the LM but with fewer memory requirements. Furthermore the SBTP combines training and pruning of a network into one comprehensive procedure. The effectiveness of the two algorithms is evaluated using three examples. Comparisons are made with some existing algorithms. Some convergence properties of the two algorithms are given to qualitatively evaluate the performance of the algorithms.

[Study on the relationship between provenance, leaf type and quality in Magnolia officinalis]

An analysis of effective ingredients in 20 to 29 year old Magnolia officinalis of three different leaf types coming from various sources shows that the content of phenols differ extremely significantly in various leaf types which are a key to determination of quality of Magnolia officinalis also varies significantly among different sources which only have a significant effect on the content of magnolol. Varieties and types cultivated in different places are responsible for the variation in content of magnolol. The conclusions obtained from this study coincide with the traditional insight into quality of Magnolia officinalis.

[Human interleukin-13 cDNA cloning and expression]

OBJECTIVE

To construct an efficient expression system for HIL-13 in prokaryotic cells.

METHODS

After Amplified by RT-PCR, The cDNA fragment encoding HIL-13 was inserted into pGEX-2T plasmid and expressed under induced condition.

RESULTS

HIL-13 cDNA was obtained. Recombinant plasmid pGEX-2T HIL-13 was constructed and sequenced, the inserted fragment of the recombinant plasmid was confirmed to be HIL-13 cDNA. HIL-13 was expressed as a fusion protein with glutathione-s-transferase (GST-HIL-13, MW = 39,000).

CONCLUSIONS

(1) HIL-13 cDNA has been obtained from T lymphocytes. (2) The rate of expression of HIL-13 in prokaryotic cells is about 37%.

[Chemical constituents of the leaves of Crataegus scabrifolia (Franch.) Rehd]

OBJECTIVE

To explore the medicinal resources of Crataegus and seek compounds with pharmaceutical effects.

METHOD

Column chromatography was employed for the isolation and purification of constituents and the structures were elucidated by spectral analysis and chemical evidence.

RESULT

Six compounds were obtained and identified as rutin, hyperoside, vitexin, ursolic acid, daucosterol, and nonacosanol.

CONCLUSION

The main constituents of the leaves of Crataegus scabrifolia are flavonoids.

[Cloning of human papillomavirus type 16 E7 gene and expression in E. coli]

OBJECTIVE

To study the biological activity of the E7 gene of human papillomavirus 16 (HPV16).

METHODS

E7 gene from the cervical carcinoma of Chinese women was amplified by the PCR. The E7 DNA was sequenced and compared with the prototype E7 gene of HPV 16.

RESULTS

It showed no mutations. However when E7 gene was inserted into the prokaryotic expression vector pGEX-2T and the fused E7 protein was efficiently expressed in E. Coli (DH5 alpha). The E7 antibody could combine specifically with this fused protein by Western blot technique.

CONCLUSIONS

The result might aid for epidemiological investigation and preparation of the vaccine.

Regulation by ARIA/neuregulin of acetylcholine receptor gene transcription at the neuromuscular junction

Transcription of genes encoding nicotinic acetylcholine receptor (AChR) subunits (alpha, beta, gamma or epsilon, and delta) is highest in nuclei localized to the synaptic region of the muscle which contributes to maintain a high density of AChRs at the postjunctional membrane. ARIA (AChR inducing activity) is believed to be the trophic factor utilized by motor neurons to stimulate AChR synthesis in the subsynaptic area. ARIA stimulates tyrosine phosphorylation of the erbB proteins and activates the MAP kinase pathway which is required for the ARIA-mediated induction of AChR genes.

Weight-value convergence of the SOM algorithm for discrete input

Some insights on the convergence of the weight values of the self-organizing map (SOM) to a stationary state in the case of discrete input are provided. The convergence result is obtained by applying the Robbins-Monro algorithm and is applicable to input-output maps of any dimension.

A systematic and effective supervised learning mechanism based on Jacobian rank deficiency

Most neural network applications rely on the fundamental approximation property of feedforward networks. Supervised learning is a means of implementing this approximate mapping. In a realistic problem setting, a mechanism is needed to devise this learning process based on available data, which encompasses choosing an appropriate set of parameters in order to avoid overfitting, using an efficient learning algorithm measured by computation and memory complexities, ensuring the accuracy of the training procedures as measured by the training error, and testing and cross-validation for generalization. We develop a comprehensive supervised learning algorithm to address these issues. The algorithm combines training and pruning into one procedure by utilizing a common observation of Jacobian rank deficiency in feedforward networks. The algorithm not only reduces the training time and overall complexity but also achieves training accuracy and generalization capabilities comparable to more standard approaches. Extensive simulation results are provided to demonstrate the effectiveness of the algorithm.

Identification of an element required for acetylcholine receptor-inducing activity (ARIA)-induced expression of the acetylcholine receptor epsilon subunit gene

Acetylcholine Receptor (AChR)-inducing activity (ARIA) is believed to be the trophic factor utilized by motoneurons to stimulate AChR synthesis in the subsynaptic area. Among the four AChR subunit genes, the epsilon subunit gene is strictly expressed in nuclei localized to the synaptic region of the muscle. To understand mechanisms of the regulation of synapse-specific transcription, we studied the promoter activity of the 5'-flanking region of the AChR epsilon subunit gene in response to ARIA. Transgenes containing the wild type or mutant 5'-flanking regions upstream of a luciferase gene were transfected in C2C12 muscle cells. The promoter activity of these transgenes was determined by assaying activity of expressed luciferase. Analyzing a combination of 5' deletion and site-directed mutants, we identified a 10-nucleotide element (position -55/-46), which was crucial for ARIA-induced expression from the epsilon subunit promoter. This element was named ARE for ARIA-responsive element. Mutation of ARE greatly diminished ARIA-induced transgene expression and deletion of ARE abolished completely the ARIA response. Electrophoretic mobility shift analyses revealed a DNA binding activity in muscle nuclear extract that interacted with ARE. Such interaction was enhanced by ARIA stimulation of muscle cells and appeared to be dependent on nuclear protein phosphorylation.

Self-organization of firing activities in monkey's motor cortex: trajectory computation from spike signals

The population vector method has been developed to combine the simultaneous direction-related activities of a population of motor cortical neurons to predict the trajectory of the arm movement. In this article, we consider a self-organizing model of a neural representation of the arm trajectory based on neuronal discharge rates. As self-organizing feature map (SOFM) is used to select the optimal set of weights in the model to determine the contribution of an individual neuron to an overall movement representation. The correspondence between movement directions and discharge patterns of the motor cortical neurons is established in the output map. The topology-preserving property of the SOFM is used to analyze the recorded data of a behaving monkey. The data used in this analysis were taken while the monkey was tracing spirals and doing center-->out movements. The arm trajectory could be well predicted using such a statistical model based on the motor cortex neuronal firing information. The SOFM method is compared with the population vector method, which extracts information related to trajectory by assuming that each cell has a fixed preferred direction during the task. This implies that these cells are acting along lines labeled only for direction. However, extradirectional information is carried in these cell responses. The SOFM has the capability of extracting not only direction-related information but also other parameters that are consistently represented in the activity of the recorded population of cells.

[Study on the quality standard of Hippophae rhamnoides oil for pharmaceutical uses]

The quality control methods of the seed oil and fruit oil of Hippophae rhamnoides are studied. The physical and chemical factors are determined and the identification and determination methods for the bioactive compnents a-tocopherol and carotenes are established.

Induction of acetylcholine receptor gene expression by ARIA requires activation of mitogen-activated protein kinase

Transcription of genes encoding nicotinic acetylcholine receptor (AChR) subunits (alpha, beta, gamma or epsilon, and delta) is highest in nuclei localized to the synaptic region of the muscle, which contributes to maintain a high density of AChRs at the postjunctional membrane. ARIA (AChR inducing activity) is believed to be the trophic factor utilized by motor neurons to stimulate AChR synthesis in the subsynaptic area. To elucidate the signaling mechanism initiated by ARIA, we established stable C2C12 cell lines carrying the nuclear lacZ gene under the control of the mouse epsilon subunit promoter or chicken alpha subunit promoter. ARIA stimulated tyrosine phosphorylation of erbB proteins in these C2C12 cells within 15 s with a peak at 5 min. Immediately following tyrosine phosphorylation of erbB proteins, mitogen-activated protein (MAP) kinase was activated which occurred within 30 s and peaked at 8 min after ARIA stimulation. Concomitantly, expression of AChR genes was induced by ARIA. ARIA-induced AChR subunit transgene expression was observed only in differentiated myotubes and not in myoblasts, suggesting that downstream signaling component(s) are regulated in a manner dependent on the myogenic program. Inhibition of the MAP kinase activity by using a specific MAP kinase kinase inhibitor or by overexpressing dominant negative mutants of Raf or MAP kinase kinase attenuated or abolished the ARIA-induced activation of AChR alpha and epsilon subunit gene expression. These results indicate that regulation of AChR gene expression by ARIA in C2C12 cells requires activation of the MAP kinase signaling pathway.

Differentiation of pseudocondyloma of vulva and condyloma acuminata by dot blot hybridization and polymerase chain reaction

This study differentiated pseudocondyloma of vulva from condyloma acuminata using dot blot hybridization and polymerase chain reaction (PCR). A total of 27 cases of pseudocondyloma of vulva and 65 cases of condyloma acuminata were selected for the study. The genital lesions were examined clinically and were biopsied. Each biopsy was subjected to histological examination and HPV DNA analysis by dot blot hybridization and PCR. Dot blot analysis detected HPV DNA in 19(82.6%) out of 23 cases of condyloma acuminata and 2(25%) out of 8 cases pseudocondyloma of vulvae (P < 0.05). PCR detected HPV DNA in 51(92.7%) out of 55 cases of condyloma acuminata, compared with none in 23 cases of pseudocondyloma (P < 0.001). HPV DNA was present in the majority of condyloma acuminata specimens, HPV 6 and 11 were the predominant types. Peudocondyloma is probably not associated with HPV. PCR was the most sensitive and useful technique for HPV DNA detection.

Picosecond optical bistability in metallophthalocyanine-doped polymer film waveguides

Ultrafast optical bistability was observed in a planar optical waveguide made with a 2,9,16,23-tetraoctadecanoylamido-substituted vanadyl phthalocyanine-doped polystyrene film. Input-output curves with hysteresis characteristics were measured with laser pulses of 60-ps pulse width at 532 nm. The switchup and switchdown times were less than 10 and 20 ps, respectively. The origin of the nonlinearity giving rise to optical bistability was predominantly electronic effects.

[The reversing effect of HPV-16 E6E7 gene antisense plasmid on the HPV-16 positive human cervical carcinoma cells]

Antisense reconstruct, p16as E6E7Neo, harboring HPV-16E6E7 gene of which the expression is regulatable by dexamethasone was constructed. Calcium phosphate mediated transfection was employed to transduce this antisense reconstruct into HPV-16 positive CasKi cell line and HPV negative C-33A cell line (both derived from human cervical carcinoma) respectively. After dexamethasone was added into the culture medium to induce the expression of E6E7 antisense gene, the malignity of CasKi cells were reversed, while the growth characteristics and malignity of C-33A cells were unchanged. The results show that the reversing effect on CasKi cell is specific and mediated by inhibition of expression of E6E7 gene. It also demonstrated a more profound pathogenic role of HPV-16 E6E7 gene in the tumorogenesis of cervical carcinoma and provides a possibility for gene therapy of this tumor.

[Human papillomavirus, human cytomegalovirus and p53 gene in cervical carcinoma]

OBJECTIVE

To investigate the role of human papillomavirus (HPV) human cytomegalovirus (HCMV) infections and p53 gene mutations in the oncogenesis of cervical cancer and to clarify the association between p53 inactivation and the presence of HPV DNA.

METHODS

We examined 38 primary cervical carcinomas and 21 normal cervical specimens for the presence of HPV and HCMV DNA sequences by multiple primers PCR and nest primers PCR. The structure of p53 gene (exons 6-8) was also analyzed by PCR-SSCP silver staining method.

RESULTS

Mutations of p53 gene (exon 7) were detected in 2 of 38 tumors. One of the cases with p53 mutation was positive for HPV 16 and two positive for HCMV. HPV 16 and 18 infections were noted in 63.2% (24/38) of the tumors, the positive rate of HCMV was 84.2% (32/38). However, HPV 16,18 and HCMV infection occurred in 4.8% and 38.1% respectively in 21 normal cervical specimens. 21 of the 24 HPV 16,18 positive tumors were also HCMV positive, but none of the normal cervical tissues was infected with both HPV and HCMV.

CONCLUSION

Detection of p53 mutations in cervical carcinoma is infrequent and apparently independent of HPV infection. Cervical carcinoma is strongly associated with HPV 16 and 18 infection. A synergistic interaction may occur between HPV and HCMV infections in the oncogenesis of cervical cancer.

Light-induced noncentrosymmetry in acceptor-donor-substituted azobenzene solutions

Light-induced noncentrosymmetry was achieved experimentally in acceptor-donor-substituted azobenzene solutions and observed by phase-matched nondegenerate six-wave mixing. The microscopic origin of the induced noncentrosymmetry was found to be orientational hole burning, which was distinguished directly with net orientation of molecules by experimental observations. The decay time of the induced noncentrosymmetry depended on the rotational orientation time of the sample's molecule, which varied linearly with the viscosity of the solvent.

Tyrosine phosphorylation and synapse formation at the neuromuscular junction

Protein tyrosine phosphorylation is prevalent throughout the nervous system. It has been implicated to play an important role in the development and maintenance of neuronal functions. In the past few years significant advances have been made in our understanding of the molecular mechanisms of synapse formation and synaptic plasticity. Protein tyrosine phosphorylation appears to be important in the neuron-induced synthesis of the nicotinic acetylcholine receptor and aggregation of synaptic proteins at the neuromuscular junction during development. In addition, protein tyrosine phosphorylation may regulate the ion channel activity of the nicotinic acetylcholine receptor.

A computationally efficient method for solving the redundant problem in biomechanics

Determining the optimal set of musculotendon forces with which to produce a forward dynamic simulation of movement typically involves a huge investment of time and computational resources. A new, computationally efficient method is proposed that simultaneously achieves the desired trajectory and the dynamically optimized set of muscle stresses, and hence forces, according to the maximal endurance criterion function of Crowninshield and Brand (1981). Muscle-induced accelerations of the system resulting from unit stress contractions of individual muscles are superposed via the new pseudoinverse method to yield the desired motion trajectory. The method is tested on a control problem involving a five degree-of-freedom (DOF), 30 muscle, upper extremity model, which incorporates a dual rigid-body forearm to represent pronation and supination more adequately. The pseudoinverse method delivered the desired motion to within 0.25 degrees for each DOF during a three-second simulation. It is anticipated that the methodology can be easily and accurately applied to other highly redundant optimal control problems in biomechanics.

[Detection of p53 mutation using PCR-SSCP silver staining method]

A simple and sensitive technique to detect point mutation of the p53 gene using silver staining method for single-strand conformation polymorphism analysis of polymerase chain reaction (PCR-SSCP) is reported. In this study, the aberrations of the p53 gene (exon 6-8) in clinical specimens of primary cervical carcinoma were examined. Of 27 tumor tissues 2 samples showed mutations of p53 exon 7. Absence of abnormal bands in the p53 exon 6-8 in all ten normal cervical tissues. It appears that inactivation of p53 gene by point mutation is infrequent in clinical samples of human cervical carcinomas.

Analysis and synthesis of a class of discrete-time neural networks with multilevel threshold neurons

In contrast to the usual types of neural networks which utilize two states for each neuron, a class of synchronous discrete-time neural networks with multilevel threshold neurons is developed. A qualitative analysis and a synthesis procedure for the class of neural networks considered constitute the principal contributions of this paper. The applicability of the present class of neural networks is demonstrated by means of a gray level image processing example, where each neuron can assume one of sixteen values. When compared to the usual neural networks with two state neurons, networks which are endowed with multilevel neurons will, in general, for a given application, require fewer neurons and thus fewer interconnections. This is an important consideration in VLSI implementation.

Prevalence of human papillomavirus DNA sequences in an area with very high incidence of cervical carcinoma

To improve our understanding of the relationship and possible associations between human papillomavirus (HPV) infection and the development of cervical malignancies, the presence of multiple types of HPV DNA sequences in cervical carcinoma was determined in Chinese citizens living in two different geographical locations where the incidences of cervical carcinoma are either relatively low or extremely high. HPV DNA sequences were found in 88.5% (54 of 61) of Chinese cervical carcinoma patients living in Taiwan, where the prevalence of cervical carcinoma is 23.7 per 100,000 women. In contrast, in LueYang in Shanxi province, an area with a very high prevalence of cervical carcinoma (1,026 per 100,000 women), only 57.1% (28 of 49) of Chinese cervical carcinoma patients were found to be infected with genital HPV. This result seems to suggest that either the presence of HPV may have different implications in different populations or HPV infection may not be the only factor that determines the development of cervical carcinoma, at least in certain geographical areas. Recently acquired transient or chronic persistent HPV infection may have a different outcome with regard to cervical carcinogenesis. Alternatively, other factors, such as host determinants, may play a role in the development of cervical carcinoma.

[Study of histopathological and ultrastructural differences between condylomata acuminata and pseudocondyloma of vulvae]

Histopathological alterations of condylomata acuminata were characterized by hyperkeratosis, parakeratosis, acanthosis, elongation of the rete ridges, pseudoepitheliomatous hyperplasia, discrete or grouped koilocytes, proliferation and dilatation of dermal capillaries, lymphocytic and histocytic infiltration around dermal capillaries. Histopathological pattern of pseudocondyloma of vulvae were characterized by finger-shaped configuration, epithelium was similar to normal of mucous membrane without atypia. The lesion was composed of a rich vascular network surrounded by connective tissue and a mild lymphocytic infiltration. Ultrastructural alterations of condylomata acuminata were characterized by proliferation of basal cells, enlarged and swollen nuclei in all layers, 1-4 large nucleoli, 1-3 nuclear bodies, interchromatin granules and perichromatin granules in some proliferating nuclei, swollen mitochondria, dilated endoplasmic reticulum, and dissolved glycogen. Ultrastructural alterations of pseudocondyloma of vulvae were characterized by proliferation of mucomembranous epithelial cells, mild swollen nuclei, 1-2 nucleoli, no nuclear body interchromatin and perichromatin granule, the dilatation of interstitial capillaries, and abundant fibril bundles in the dermis. Thus, the histopathological and ultrastructural manifestations of condylomata acuminata and pseudocondyloma of vulvae were significantly different. It may be of help in differentiation between the two disease.

The best approximation to C(2) functions and its error bounds using regular-center Gaussian networks

Gaussian neural networks are considered to approximate any C(2) function with support on the unit hypercube I(m)=[0, 1](m) in the sense of best approximation. An upper bound (O(N(-2))) of the approximation error is obtained in the present paper for a Gaussian network having N(m) hidden neurons with centers defined on a regular mesh in I(m).

[Molecular and ultrastructural study on the relationship between human papillomavirus and female genital condyloma in China]

From the results of DNA hybridization, it has been shown that there is a close relationship between HPV 16 and human uterine cervical carcinoma in China, and also that the viral DNA is integrated into the cancer cell genome. Genital condyloma revealed a high positive hybridization rate with HPV 11 DNA, and the viral DNA presented as an episome apart from the cell genome. Under the electron microscope, the inter and perichromatin granules as well as nuclear bodies were observed in all biopsies with positive hybridization, but no HPV particle was found in cancer cells, besides these two kinds of chromatin granules. Human papillomavirus nucleocapsid particles were observed in the nuclei of some genital condyloma cells. Electron-dense matrix aggregates of different sizes were seen in the perinuclear cytoplasm and in the nuclei. This kind of structure may be related to the process of HPV maturity, but its nature remains to be studied.