Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice

Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.

[Investigation of a gas chromatographic column system for the on-line analysis of gaseous components in de-propane tower of pyrolysis equipment]

Multi-dimensional gas chromatograph has become an important process analyzer due to the advantages of high resolution and fast speed. According to the production requirement, a gas chromatographic column switching system has been investigated for the on-line analysis of gaseous components from high-pressure and lower-pressure de-propane towers of pyrolysis equipment. By using two different injection times on three injectors, and fore-flush and back-flush techniques, C2-hydrocarbons, propane, propene, methylacetylene, propadiene and C4-hydrocarbons can be separated on 7 columns in 7 minutes. The practical application showed the developed column system is suitable for the on-line monitoring of the production process.

A protein kinase C-independent pathway leading to c-Jun-dependent expression of 100-kDa Ras GTPase-activating protein in JEG-3 human choriocarcinoma cells

Although the 100-kDa Ras GTPase-activating protein (p100 RasGAP) has been reported to exist specifically in human placental trophoblasts, the molecular mechanisms responsible for regulating its expression remain unclear. In this study we used okadaic acid, an inhibitor of serine/threonine phosphatase 1 and 2 A, as a probe to explore the signaling pathway regulating the expression of p100 RasGAP in JEG-3 human placental choriocarcinoma cells. Treatment of JEG-3 cells with okadaic acid provoked dose- and time-dependent stimulation of p100 RasGAP expression without marked modification of expression of p120 RasGAP, another isoform of RasGAP. Co-treatment of cells with okadaic acid and the protein kinase C activator, phorbol 12-myristate 13-acetate, exerted an additive effect on p100 RasGAP induction. Moreover, the response of the p100 RasGAP de novo synthesis to okadaic acid was not affected by the selective inhibitor of protein kinase C, GF 109203X. Thus this study identified a novel signaling pathway regulating p100 RasGAP expression, which is independent of protein kinase C. In addition, okadaic acid treatment resulted in the activation of ERK2 (p42 MAP kinase) and the induction of both c-Jun and c-Fos proteins without activating JNK (c-Jun NH2-terminal kinase). Significantly, blockade of c-Jun expression with antisense c-jun oligonucleotides suppressed p100 RasGAP expression. Taken together, it is concluded that okadaic acid induces the expression of p100 RasGAP protein in JEG-3 cells preceded by activation of ERK and AP-1 cascade, and that this okadaic acid-induced p100 RasGAP expression is independent of protein kinase C-mediated pathway but requires c-Jun/AP-1 function.

Molecular maps of neural activity and quiescence

The rapid accumulation of inducible transcription factors (ITFs), such as c-Fos and Zif268, in activated neurons combined with histological methods that offer detection at the cellular level are key features that have led to their wide use in visualizing activated neurons. There are two major drawbacks of ITFs that limit their use in the CNS--cell-type expression specificity and stimulus-transcription coupling uncertainty. Recent technical advances in the field of molecular activity mapping now permit dual-labeling approaches that help resolve some of these ambiguities and identify neurons that are activated by different sensory stimuli. Furthermore, the recent identification of the robl/LC7-like gene, which shows immediate-early repression after stimulation, may have utility in functional mapping where it can be used to delineate quiescent neurons and serve as a complement to molecular activity markers.

Temperature and air pollution as risk factors for heat stroke in Tokyo, July and August 1980-1995

Heat stroke is associated with prolonged exposures to high air temperatures that usually occur in the summer months of July and August in Tokyo, Japan. Also during July and August, residents of Tokyo are often exposed simultaneously to high concentrations of air pollutants. To assess the impacts of these combined exposures, daily numbers of heat stroke emergency transport cases/million residents for Tokyo were stratified by gender and three groups: 0-14, 15-64; and > 65 years of age, for the months of July and August in 1980-1995. A regression model was constructed using daily maximum temperature (Tmax) and daily average concentrations of NO2 and O3 as model covariates. Classification indices were added to make it possible to compare the expected number of heat stroke cases by age and gender. Lag times of 1-4 days in Tmax and air quality covariates and terms to account for interactions between pairs of model covariates were also included as additional risk factors. Generalized linear models (GLMs), assuming a Poisson error structure for heat stroke emergency transport cases, were used to determine which covariates were significant risk factors for heat stroke for the three age groups of males and females. Same-day Tmax and concentrations of NO2 were the most significant risk factors for heat stroke in all age groups of males and females. The number of heat stroke emergency transport cases/million residents was greater in males than in females in the same age groups. The smallest number of heat stroke emergency transport cases/million residents occurred for females 0-14 years of age and the greatest number of heat stroke emergency transport cases/million residents occurred for males > 65 years of age.

[Anatomic investigation of facial canal related to middle ear surgery]

OBJECTIVE

To avoid hurting facial nerve in middle ear surgery.

METHOD

20 adult head cadavers with 40 sides tempotal bone were dissected and investigated.

RESULT

1. Prevalence of dehiscent facial nerve canal was 32.5% (13/40), while 2.5% (1/40), 27.5% (11/40), 7.5%(3/40) incidence facial nerve canal were found in the labyrinthine, horizontal, vertical segment respectively. 2. Distance between the vertical portion of facial nerve and posterior semicircular canal was 0.62-5.08(2.48 +/- 0.63) mm. Interspace between the vertical portion of facial nerve and tympanic chorda was 0-4.62 (2.12 +/- 0.76) mm at the level of tympanic ditch, while interspace between the vertical portion of facial nerve and tympanic ditch was 2.96-8.82 (5.86 +/- 1.62) mm. 3. Distance between horizontal portion of facial nerve and lateral semicircular canal was 0-3.02 (1.92 +/- 0.84) mm. Interspace between horizontal portion of facial nerve and stapedial board was 0.92-4.06(2.14 +/- 0.90) mm.

CONCLUSION

Familiarity with facial nerve procession should be favorable to decrease facial paralysis with middle ear surgery.

Mechanisms of spiroplasma genome variation associated with SpV1-like viral DNA inferred from sequence comparisons

Genomes of Spiroplasma citri strains have rearranged frequently during their evolution, partly due to multiple integrated sequences of spiroplasma viruses. To understand better the role of viral sequences in genome evolution, we examined available nucleotide sequences of viruslike elements in the S. citri chromosome. Comparison of integrated and nonintegrated sequences of spiroplasma virus SpV1-C74 DNA suggested that it is an encapsidated form of the circular transposition intermediate belonging to an insertion sequence (IS3) family member. One SpV1-C74 viral DNA fragment was identified as interrupting the remains of a DNA adenine modification methylase gene. A viral DNA insertion of SpV1-R8A2 B DNA had hallmarks of having suffered an internal deletion by a site-specific recombination system. Homologous recombination likely was responsible for several deletions within viral DNA. A homologous recombination event was inferred between part of a viral DNA insertion and a similar chromosomal sequence. Dispersed sequences from SpV1-like C4 open reading frames (ORFs) were identified as involved in a complex deletion-inversion event. Thus, SpV1-like sequences likely have altered spiroplasma genomes by inserting within active genes, destroying their function, by providing targets for site-specific recombination, by mediating deletions of sequences adjacent to their integration sites, and by providing targets for homologous recombination, leading to inversions.

Evidence for a novel RasGAP-associated protein of 105 kDa in both mature trophoblasts and differentiating choriocarcinoma cells

A novel tyrosine-phosphorylated, RasGAP-associated protein of 105 kDa (p105) is found in normal human term placental trophoblasts, as well as in JEG-3 human choriocarcinoma cells induced to differentiate by okadaic acid (OA). This p105 RasGAP-associated protein is distinct from other RasGAP-associated proteins described so far, none of which has either a molecular size close to p105 or a trophoblastic cell origin. The p105 appears, accompanied by p120 and p100 RasGAP expression, after OA treatment of JEG-3 cells but is almost undetectable in the absence of stimulation. Moreover, the p105 is the first discovered RasGAP-associated protein bound to p100 RasGAP. The natural occurrence of the p105 in normal mature trophoblasts isolated from human term placenta suggests that it may be linked to the differentiation state of human trophoblasts. Hence, this p105 RasGAP-associated protein might be considered a marker of human trophoblast differentiation.

[Surgical reconstruction of laryngeal and tracheal stenosis]

OBJECTIVE

Reconstruction of laryngotracheal stenosis.

METHOD

According to the pathologic condition of the larynx and trachea, various surgical procedures were designed for the treatment of laryngotracheal stenosis. These techniques included endoscopic management, laser therapy and laryngotrachoetomy with autogenous tissue and stent.

RESULT

Among 36 patients, 32 were decannulated. The success rate was 88.8%.

CONCLUSION

In order to improve the curation effects of laryngjotrachal stenosis, the choice of surgical procedure must be individualized to the pathologic condition of larynx and trachea, as well as the experience of the surgeon. Learning previous successful experience is also very important for a good result.

[Determination of 2,4-dinitrophenol by solid-phase microextraction coupled to GC/MS]

Solid-phase microextraction coupled GC/MS was investigated for the determination of 2,4-dinitrophenol in aqueous sample. Analytes were extracted by a 85 microns polyacrylate coated fiber. The fiber was then transferred into the injector of GC. Analytes were thermally desorbed and detected by GC/MS. The influences of several parameters on SPME procedure have been studied. The optimization condition was obtained: directly sampling in the water sample with the extraction period was 30 min and the desorption time 3 min at 270 degrees C. Acidification by hydrochloric acid (pH 2) and saturated salt were necessary for the best sensitivity. The precision of SPME is better than that of liquid-liquid extraction. This method is a fast, simple, and pre-concentration-free technique, which is suitable for detecting 2,4-dinitrophenol in water sample.

[Development of column switching systems in industrial gas chromatography]

According to the home-made requirement of column switching systems in 23 industrial gas chromatographs in 300,000 Tons of olefin plant, based on the research work of the expert system on gas chromatography and movement laws of compounds of interest in columns, the suitable stationary phases were defined, and the column switching systems were designed by using combined cutting techniques which consist of backflushing, fore-flushing and heart cutting, and by controlling column lengths, flows, flow directions and temperatures. The practical applications showed the column systems satisfy the on-line monitoring requirement of the production process and can be used continually for 1-3 years.

The phytopathogenic mollicute-insect vector interface: a closer look

ABSTRACT Spiroplasma citri, transmitted by phloem-feeding leafhoppers, moves from the gut lumen through the gut wall, hemolymph, and salivary glands and multiplies in insect tissues. Nontransmissible lines were deficient in their ability to cross these barriers. Molecular analysis revealed extensive chromosomal rearrangements between the transmissible and nontransmissible spiroplasma lines including a large chromosomal inversion and deletions of about 10 kb at each inversion border. One open reading frame of the deleted region, cloned from the transmissible strain BR3-3X, encodes an integral membrane protein of 58 kDa that shares limited sequence similarity with major adhesin proteins of two zoopathogenic mycoplasmas. Adhesion of spiroplasmas to cultured leafhopper cells was inhibited by proteases, suggesting that adherence to host cells is mediated by spiroplasma membrane protein(s). A hypothetical model for insect transmission of phytopathogenic mollicutes is presented.

Insulin-like growth factor I receptors are expressed by the enteroendocrine cell line STC-1: relationship with proliferation and cholecystokinin expression

Receptors for insulin-like growth factors (IGF-I and IGF-II) are expressed in mammalian intestinal epithelium. No information on the presence of IGF receptors in intestinal endocrine cells is available. We tested for IGF-I receptors the endocrine cell line STC-1, which synthesizes and processes cholecystokinin (CCK) among other peptides, and assessed the effects of IGF-I on cell growth and CCK content. Cell monolayers in serum-free culture medium specifically bound [125I]IGF-I. Scatchard analysis was consistent with a single class of high affinity binding sites (KD = 0.91 nM; Bmax = 4,700 sites/cell). In competitive binding assays, unlabeled IGF-I, IGF-II and insulin displaced in a dose-dependent manner [125I]IGF-I binding with the following potencies (KI): IGF-I (0.74 nM) > IGF-II (3 nM) >> insulin (1 microM). Affinity cross-linking with [125I]IGF-I using disuccinimidyl suberate and SDS-PAGE under reducing conditions yielded a polypeptide band with apparent Mr 130,000, consistent with the alpha-subunit of the IGF-I receptor. IGF-I and IGF-II (0.3-30 nM) dose-dependently stimulated [3H]thymidine incorporation, with a maximal response of 110% above basal. IGF-II was approximately 10-fold less potent than IGF-I, suggesting a mediation through IGF-I receptors. In addition, the numbers of cells treated with 3 nM IGF-I amounted to 116, 130 and 159% of control values after 1, 2 and 4 days of incubation, respectively (p < 0.05). A significant increase in the cell CCK contents was observed after a 48-hour exposure to 3 or 30 nM IGF-I. These results demonstrate IGF-I receptor expression by the enteroendocrine cell line STC-1. IGF-I stimulates proliferation in short-term experiments, and increases intracellular levels of CCK.

[Anatomical consideration for the injury of dacryocyst and nasolacrimal duct during intranasal sinus surgery]

Based on dissection and measurement on 20 adult head cadavers, there is the close relationship between lacrimal duct and lateral wall of the nasal cavity. The cells of anterior ethmoid sinus were classified into three degrees, according to the relationship between the anterior ethmoid sinus and the lacrimal sac fossa. The average distance is 6.74 +/- 1.72 mm between the nasolacrimal duct and the upper part of the uncinate process, 3.44 +/- 0.75 mm and 5.50 +/- 3.73 mm from the nasolacrimal duct to ethmoidal infundibulum and the maxillary ostium. The orifice of the duct most commonly opens under the insertion of the inferior turbinate anteriorly. To perform intranasal sinus surgery, the safest area and key operation approach were discussed.

[Application of nasal endoscopy and cryosurgery in transsphenoidal removal of pituitary tumors]

In order to sum up the experience of transsphenoidal resection of pituitary tumors, 60 cases operated between 1984 and 1995 were reviewed. The operation was performed via a columella nasi "V" incision and transseptal-sphenoidal approach. 0 degree and 30 degrees endoscopes were used in 16 cases and the cryotherapy was used to destroy the remnant tumor cells in 51 cases. The duration of freezing was only one minute each time and it was repeated once again after thawing. The advantages of this method were as follows: (1) wider operative field and better illumination; (2) magnified operative pictures and TV monitoring; (3) wide and changeable visual angle; (4) lack of complications such as hemorrhage, optic nerve injury, permanent diabetes insipidus. The proper applications of endoscopy and cryosurgery were recommended for transsphenoidal removal of pituitary tumors.

The effects of restorative material and location on the detection of simulated recurrent caries. A comparison of dental film, direct digital radiography and tuned aperture computed tomography

OBJECTIVES

To explore the effects of restorative material and lesion location on the detection of recurrent caries using intra-oral film, direct digital radiography and unprocessed and iteratively restored tuned aperture computed tomography (TACT) images.

METHODS

An in vitro model with simulated lesions in half the surfaces studied was used. Lesions of varying sizes were created at either the intersection of the facial or lingual wall and the gingival floor or on the gingival floor midway between the facial and lingual walls in the proximal boxes of 24 molar teeth with MOD inlay preparations that had been restored with amalgam, radiopaque composite or radiolucent composite.

RESULTS

Sensitivity and specificity values based on restoration were: amalgam: 59 and 87%; radiopaque composite: 68 and 78%; radiolucent composite: 36 and 93%; based on lesion location, mid-cervical floor region: 51 and 97%; point angle region: 44 and 90%; based on imaging modality, film: 40 and 85%; digital: 44 and 76%; unprocessed TACT slices: 50 and 87%, iteratively restored TACT images: 83 and 96%. Iteratively restored TACT images had the best intra- and inter-reader agreement.

CONCLUSIONS

The use of restorative materials with a density approximating that of enamel is more effective for the detection of recurrent caries. Lesions located at the buccal point angle or mid-gingival floor are more easily detected than at the lingual point angle region. The sensitivity and specificity of TACT and iteratively restored TACT images were superior to those of film and direct digital images.

Effects of topical antiandrogen and 5-alpha-reductase inhibitors on sebaceous glands in male fuzzy rats

The fuzzy rat, a genetic mutant between hairless and hairy albino rats, expresses androgen-dependent hypersecretion of sebum and hyperplastic sebaceous glands. Using this model for human acne, we examined the effects of inhibitors of human steroid 5 alpha-reductase isozymes, type I (MK 386) and type II (finasteride), and an androgen receptor blocker (RU58841) on regression of glandular and ductal hyperplasia. The above three agents, 1% weight volume, were dissolved into the vehicle (propylene glycol, alcohol and water) and applied on the backs of peripubertal male rats for 2 months. Control and castrate groups received vehicle alone. At 8 weeks, we examined the size the sebaceous glandular lobules and ducts in split epidermal preparations as well as in frozen sections of skin stained with osmium-potassium dichromate solution. The number of bromodeoxyuridine (BrdU)-positive cells was counted in the glandular lobes in split-skin tissues stained with BrdU immunochemistry. The results revealed that the sizes of both lobes and ducts in castrates were 40-60% smaller than in controls. RU58841 induced glandular and ductal regression equivalent to that in castrates. Finasteride induced a moderate degree of lobular and ductal reduction, whereas MK386 caused only ductal regression. Reduction of BrdU-positive cells in the sebaceous lobes was found in the skin treated with finasteride and RU58841. Serum concentrations of testosterone and dihydrotestosterone showed no significant changes in all drug-treated rats. The weight of the prostatic lobes was reduced significantly in rats treated with finasteride but not by the other two agents. RU58841 effectively counteracted endogenous androgens resulting in a suppression of growth of the sebaceous glands but not the prostate. This rodent model for androgen-dependent hyperplasia of the sebaceous glands is useful for the study of many pharmacological aspects comprising the rate of percutaneous absorption, stability and affinity to target organs of the testing compounds, and selection of adequate vehicle for topical application.

[Clinical experience of coronal flap approach in surgery of anterior skull base tumor]

Surgery of the anterior skull base tumor has been undertaken in 7 cases by coronal flap approach, of which 4 cases were malignant tumors and 3 cases were benign tumors. The dura became torn in 3 cases and resected in 2 cases due to tumor invasion. The dura and bony defects could be repaired with galea, pericranial flaps and fascia flaps of temporalis. The bigger bony defect was consolidated with scalp flap. Three out of 4 cases with malignant tumors were free of tumors for 6 years, 4 years and 17 months, respectively: 1 case died of tumor recurrence after 18 months. No case had postoperative complications.

[Simplex optimization of the automatic gas chromatographic instrument]

A simplex optimization method developed for the automatic gas chromatography is described in this paper. The instrument was developed by ourself based on a gas chromatograph and an auto-sampler, which are controlled by a computer through several assisting circuit boards. A series of chromatographic function SCRF is used in this method for searching the best column temperature for gas chromatographic separation of a given sample. A real sample is used for probation of this method and the results are discussed.

Molecular characterization of a gene encoding a membrane protein of Spiroplasma citri

A 9.6-kb genomic DNA segment, previously cloned from the phytopathogen Spiroplasma citri BR3-3X [Fletcher et al. (1981) Phytopathology 71, 1073-1080], contained several open reading frames including one encoding a 58-kDa protein. In this work, the transcription initiation site of the P58 mRNA was mapped and part of the gene was expressed in Escherichia coli as a fusion protein. A synthetic peptide, whose sequence is included in the fusion protein, was produced. Antibodies against both the fusion protein and the peptide reacted with a 60-kDa protein in a S. citri total protein extract. Hydrophobicity characteristics of this protein and its fractionation into the detergent phase indicated that P58, which shares limited sequence similarity with the adhesin of Mycoplasma hominis and the attachment protein of M. genitalium, is an integral membrane protein.