[Study on seroprevalence of Helicobacter pylori infection among upper digestive tract cancer patients and their kindreds]

OBJECTIVE

In order to analyse the association between Hp infection and the risk of upper-digestive tract cancer.

METHODS

In Huaian and Pizhou cities, Jiangsu province, Hp IgG quantitative-enzyme-immunoassay methods was used to identify IgG to H.pylori in the serum of 312 cases of upper-digestive tract cancer patients and their kindreds.

RESULTS

(1) The level of IgG to H. pylori and the IgG positive rate (50.0%) in gastric cancer patients were both higher than that of cardia and esophageal cancer patients (P > 0.05, chi 2 test) but no significant differences were observed between cardia and esophageal cancer patients, 3 types of cancer patients and their kindreds; (2) the overall positive rates of both patients and kindreds in gastric cancer families (27.1%) were significantly higher than that of cardia or esophageal cancer families (P < 0.05) but no significant differences were observed between cardia and esophageal groups.

CONCLUSION

H.pylori infection was not thought to be correlated with the development of gastric cancer, although higher clustering of Hp infection in families afflicted with gastric cancer was noticed.

Establishment and cellular characteristics of a hepatocyte cell line (OUMS-31) derived from an acatalasemic mouse

Liver cell lines with very low catalase activity were established from an acatalasemic mouse. Hepatocytes isolated by a collagenase-liver-perfusion technique were cultured in Williams' E medium supplemented with 10% fetal bovine serum. The acatalasemic liver cell line showed approximately 20% of the catalase activity of a normal mouse liver cell line, whereas its glutathione peroxidase activity was approximately equal to that of the normal liver cell line. DNA sequence analysis of this cell line showed the same mutation in the catalase gene as is seen in the acatalasemic mouse. Our observation of intracellular content of hydrogen peroxide (H2O2) radical and increased susceptibility of the cells to H2O2 were compatible with the existence of low catalase activity in the acatalasemic mouse. This hepatocyte cell line should be useful for studying effects of oxidative radical stress at the cellular level.

Activation of caspases in p53-induced transactivation-independent apoptosis

Though p53-induced apoptosis plays an important role in tumor suppression, the mechanism(s) by which p53 induces apoptosis is still unclear. To elucidate the p53-induced apoptotic pathway, we examined the role of p53 transactivation activity and caspase in J138V5C cells carrying a human temperature-sensitive (ts) p53 mutant (138Ala-->Val). The results showed that p53-induced apoptosis was not blocked by cycloheximide, which effectively prevented the expression of p53 target genes, indicating that transactivation was not essential for p53-induced apoptosis in this system. Western blot analysis showed that PARP, CPP32 and ICH-1 precursors were cleaved during apoptosis. The CPP32-preferential tetrapeptide inhibitor Ac-DEVD-CHO blocked the cleavage of ICH-1 and PARP precursors, suggesting that CPP32 or some other DEVD-sensitive caspase(s) is the upstream activator of ICH-1. We also examined the role of the Fas pathway by using Fas and Fas ligand-neutralizing antibodies. Both antibodies failed to block p53-induced apoptosis, suggesting that the Fas pathway was not essential for p53-induced apoptosis in this system. Taken together, our results indicate that p53-induced, transactivation-independent apoptosis in Jurkat cells involves sequential activation of CPP32 or some other DEVD-sensitive caspase(s) and ICH-1, via a Fas-independent pathway.

Mitral valve replacement with complete mitral leaflet retention: operative techniques

BACKGROUND AND AIMS OF THE STUDY

This report describes surgical indication and operative technique of complete preservation of the mitral valvular and subvalvular apparatus during mitral valve replacement.

METHODS

Twenty patients, 12 with rheumatic lesions and eight with congenital lesions, were operated between 1991 and 1996. The left atrium was opened using a trans-septal approach through the right atrium in 17 patients, and at the intra-atrial groove in three. The valve was sized without excising any mitral valvular or subvalvular tissue. Teflon pledget-reinforced horizontal mattress valve sutures were passed from the left atrium, through the mitral annulus, around the free edge of mitral leaflet, and up through the prosthetic sewing ring. The prosthetic valve was seated and the sutures tied, reefing the native leaflets and compressing them between the sewing ring and native annulus. Thus, chordal tension on the ventricle was evenly maintained.

RESULTS

There was no operative or late death. Postoperative results were excellent. Echocardiography showed that none of the patients had any observable anterior leaflet and redundant subvalvular tissue in the left ventricular outflow tract (LVOT); thus, neither LVOT obstruction nor interference with prosthetic valve function occurred.

CONCLUSIONS

Based on these findings, it is suggested that when mitral valve replacement is required in patients with mitral insufficiency (MI) or MI with mild stenosis, the mitral valvular and subvalvular tissue should be completely preserved.

[Biological responses of a Streptomyces strain producing-Nikkomycin to space flight]

In order to see biological responses to the production of Nikkomycins in general and Nikkomycin X and Z in particular by space conditions, Streptomyces ansochromogenus, a Nikkomycins-producing strain, was carried onboard a satellite for 15 d in 1996. Several strains were isolated from the treated sample and found that the productivity of Nikkomycins in all was increased by 13-18 percent, and the proportion of Nikkomycin X and Z increased correspondingly. Besides, some biological properties of the isolated strains varied markedly.

Abnormally high levels of cystatin S in submandibular glands, saliva, and gingiva of plaque-resistant rats

To identify salivary biomarkers of periodontal diseases, we used plaque-resistant and -susceptible rats as animal models. The levels of salivary cystatin S in saliva, salivary glands, and gingiva were tested in Nembutal-anesthetized young and adult plaque-resistant and -susceptible rats of both sexes with and without chronic treatment with isoproterenol. Isoproterenol was injected i.p. once a day for 4 or 6 consecutive days. Isoelectric focusing electrophoresis by the PhastSystem and the western blotting method were used to separate different proteins and to identify a salivary cystatin S band in these samples. The expression of salivary cystatin S mRNA was also determined by the northern blotting method. Depending upon the types of agonists, a few differences were observed in secretory functions between both strains of rats in both sexes, but the levels of salivary cystatin S in saliva elicited from the submandibular gland and in the extracts of the submandibular glands and gingiva were significantly higher in plaque-resistant rats when compared with those of plaque-susceptible rats in both sexes. However, no significant difference was seen between the strains after chronic treatment with isoproterenol. The N-terminal 26-amino-acid sequence of salivary cystatin S purified from submandibular saliva of plaque-resistant rats was identical with that purified from submandibular saliva of Sprague-Dawley rats subjected to chronic treatment with isoproterenol. The expression of salivary cystatin S mRNA was dramatic in the submandibular glands of the plaque-resistant rats and in the submandibular glands of Wistar rats subjected to chronic treatment with isoproterenol, but not in those of plaque-susceptible rats. These results suggest that salivary cystatin S might be a good biomarker in distinguishing between the two strains of rats and that its concentration is correlated with plaque resistance.

Gene expression of alpha1-6 fucosyltransferase in human hepatoma tissues: a possible implication for increased fucosylation of alpha-fetoprotein

The 1-6 fucosylated -fetoprotein (AFP) present in serum of patients with hepatocellular carcinoma (HCC) has been employed for the differential clinical diagnosis of HCC from chronic liver diseases. The molecular mechanism by which this alteration occurs, however, remains largely unknown. To address this issue, we purified GDP-L-Fuc:N-acetyl-beta-D-glucosaminide 1-6 fucosyltransferase (1-6 FucT), an enzyme involved in the 1-6 fucosylation of N-glycans from porcine brain, as well as from a human gastric cancer cell line, and cloned their genes. In this study, levels of 1-6 FucT mRNA expression and the activity of this enzyme for 12 human HCC tissues were examined and compared with that in surrounding tissues and normal livers. The mean +/- SD for 1-6 FucT activity was 78 +/- 41 pmol/h/mg in normal control liver, 202 +/- 127 pmol/h/mg in adjacent uninvolved liver tissues (chronic hepatitis: 181 +/- 106 pmol/h/mg; liver cirrhosis: 233 +/- 164 pmol/h/mg), and 195 +/- 72 pmol/h/mg in HCC tissues. The mRNA expression of 1-6 FucT was also enhanced in proportion to enzymatic activity except for a few cases, suggesting that 1-6 FucT expression is increased in chronic liver diseases, especially liver cirrhosis. Transfection of 1-6 FucT gene into cultured rat hepatocytes markedly increased 1-6 FucT activity and led to an increase in lens culinaris agglutinin (LCA) binding proteins in both cell lysates and condition media. When the 1-6 FucT gene was transfected into a human HCC cell line, Hep3B, which originally showed low levels of 1-6 FucT expression, 1-6-fucosylated AFP was dramatically increased in the condition media. Collectively, these results suggest that the enhancement of 1-6 FucT expression increased the fucosylation of several proteins, including AFP, and that the level of 1-6-fucosylated AFP in patients with HCC was in part caused by up-regulation of the 1-6 FucT gene expression.

[Dissection and cytogenetic localization of the phenotypes of the 5p deletion syndrome]

OBJECTIVE

To classify the phenotypes of the short arm of chromosome 5 (5p) deletion syndrome and to localize their corresponding regions in the human genome.

METHODS

A hundred and six patients, together with most of their parents and sibs, were analysed both cytogenetically and clinically. The dissection of the syndrome and cytogenetic localization of each phenotype was made by relating the clinical data to the breakpoints involved in the deletions.

RESULTS

The 5p deletion syndrome was classified into 8 types based on the combination of the clinical data and high-resolution banding analysis.

CONCLUSIONS

The dissection of the "5p deletion syndrome", a term with refined concept suggested by us, and the cytogenetic localization of each distinct phenotype will provide the clear cut criteria for clinical and cytogenetic diagnosis of the 5p-patients, as well as the candidate regions for positional cloning of the gene(s) repossible for the phenotypes.

Regioselective synthesis of ethoxylated glycoside esters using beta-glucosidase in supersaturated solutions and lipases in organic solvents

Three ethoxylated glycosides, tetraethylene glycol beta-D-glucoside, tetraethylene glycol beta-D-xyloside, and methoxy triethyleneglycol beta-D-glucoside, were prepared via almond beta-glucoside-catalyzed (trans)glycosylation carried out in supersaturated solutions of glucose or p-nitrophenyl beta-D-xyloside and the respective polyethylene glycols. The products were isolated and further modified by enzymatic esterification with Candida antarctica and Mucor miehei lipases. The latter enzyme showed a much greater selectivity for the primary hydroxyl group on the polyethylene glycol chain of the glucoside substrate, thus enabling us to obtain exclusively the corresponding monoester, omega-O-oleoyl tetraethylene glycol beta-D-glucoside. Novozyme was used for the preparative synthesis of two other monoesters, 6-O-oleoyl (methoxy triethyleneglycol) beta-D-glucoside and omega-O-oleoyl tetraethylene glycol beta-D-xyloside. Two diesters, di-oleoyl tetraethylene glycol beta-D-glucoside and tetraethylene-bis(6-0-oleoyl glucoside) were also synthesized in good yields using this lipase. Copyright 1998 John Wiley & Sons, Inc.

A new human chondrosarcoma cell line (OUMS-27) that maintains chondrocytic differentiation

A new human chondrosarcoma cell line, OUMS-27, was established. Monolayer cultures consisted of elongated polygonal cells with a doubling time of 41 hr and a plating efficiency of 2.1%. After reaching confluence, the cells continued to slowly proliferate and formed nodule-like structures, which showed metachromasia when stained with toluidine blue, indicating the presence of proteoglycan. The cells in the nodules were round to polygonal in shape, multilayered and surrounded by abundant extracellular matrix. Types I, II and III collagens were identified by Northern blotting and immunostaining. The cells formed colonies (0.1%) in 0.3% soft-agar medium 3 weeks after inoculation. Inoculation of cells into athymic mice resulted in the formation of tumors at the injection site, resembling the original chondrosarcoma. These results demonstrated that OUMS-27 cells expressed a differentiated chondrocytic phenotype. Moreover, OUMS-27 cells had p53-gene mutation. Thus, the OUMS-27 cell line can provide a useful model not only for studies on human chondrocyte but also for basic studies on the diagnosis, treatment and etiology of human chondrosarcoma.

Reduced metastatic potential and c-myc overexpression of colon adenocarcinoma cells (Colon 26 line) transfected with nm23-R2/rat nucleoside diphosphate kinase alpha isoform

Increased expression of nm23/nucleoside diphosphate kinase (NDP kinase) has been reported to be associated with both reduced metastatic potential in breast carcinoma and tumor progression in colon adenocarcinoma and lung adenocarcinoma. We examined effects of expression of nm23-R2 rat NDP kinase alpha isoform on mouse adenocarcinoma cells (Colon 26 line) and found a significant reduction of metastatic potential along with overexpression of c-myc. We also found that the proliferation rate of the transformed cells was the same as that of the control cells in culture. These results indicate that the cell growth potential in vitro is irrelevant to metastatic potential of the cells in vivo.

[The study on the attrition of molars with occlusal hypersensitivity molars in elderly people]

OBJECTIVE

To investigate the attrition of molars in old people who suffered from occlusal hypersensitivity.

METHODS

113 maxillary and mandibular molars of old people (47-74 years old) who had dentine hypersensitivity caused by attrition were studied. The Lavelle's criteria were used.

RESULTS

When the attrition reached to the e type, the rate of lesion rose up quickly (19.47%), the highest incidence was seen in g type (41.59%). The hypersensitivity occurred as 48.67% in the first molar, 51.33% in the second molar, 53.10% in enamel-dentin junction, and 38.05% in dentine concave site.

CONCLUSION

The rate of hypersensitivity rises with the severity of attrition. There is no significant difference between the first molar and the second molar, but the incidence of hypersensitivity in enamel-dentin junction is significantly higher than in dentine concave site (P < 0.05).

[Immunohistochemical study of myoglobin deletion from myocardium in hemorrhagic shock]

Myoglobin (MB) deletion from myocardium in the case of hemorrhagic shock was firstly studied by immunohistochemical and morphometry technique. The results showed that there were different degrees of segmental deletion of MB from myocardium in each case of hemorrhagic shock which has continued over an hour. The significance of these changes in forensic medicine are discussed.

Identification of two additional exons at the 3' end of the amelogenin gene

Alternative splicing of the amelogenin gene generates a family of proteins secreted by ameloblasts that are primarily responsible for tooth enamel formation. Here the presence of two additional exons, downstream of exon 7, which are followed by an alternate polyadenylation site, is reported. Long polymerase chain reaction was used with a rat genomic amelogenin template to amplify sequences downstream from the primary polyadenylation site. Within the amplified sequences, two exons of 45 bp (exon 8) and 110 bp (exon 9) were identified. The presence of these additional exons in the human and mouse genome was indicated by Southern blot analysis. Antibodies raised against a synthetic peptide corresponding to a sequence encoded by exon 9 positively stained ameloblasts in sections of developing murine and porcine unerupted teeth. These results suggest that an amelogenin protein(s) that includes sequences derived from exons 8 and 9 is synthesized by the ameloblasts.

The Multi Unit Activity analyzer: a Windows based hardware-software system for low cost, high speed analog to digital data conversion, data acquisition and window discrimination

The Multi Unit Activity analyzer is a hardware-software package for multi-purpose, two-channel data acquisition, with a computer dependent maximal digitizing frequency selectable from 1 to 27,000 s(-1) on both channels simultaneously. The hardware is connected to an IBM compatible PC through one of the serial ports (standard RS 232 interface). Software was developed to view digitized signals and record or read them on or from the harddisk. The program can also perform amplitude based window discrimination on the raw signal, on-line or during replay. The system is used for recording and analyzing multi unit activity from neuronal tissue in our electrophysiology lab but it can be applied in a variety of other settings. Basic programming routines are available that allow customized data acquisition.

Association of Ile462Val (Exon 7) polymorphism of cytochrome P450 IA1 with lung cancer in the Asian population: further evidence from a case-control study in Okinawa

Okinawa, a group of islands that lie between the East China Sea and the Pacific Ocean, 2000 km south of the Japanese main islands, has a different profile of diseases, ethnicities, and cultures than does the rest of Japan. We examined an Ile462Val polymorphism (CYP1A1*2 allele) of cytochrome P450 IA1 in a hospital-based case-control study of lung cancer patients (247 cases and 185 controls) in Okinawa to ascertain the association of this variant with lung cancer. In addition, the distribution of this genotype was studied in populations from different areas of Japan, including Tokyo (n = 69) and Iwate (northern part of Japan; n = 81), as well as in a Chinese group from the Jiangsu province (n = 39) and in an Australian Caucasian group (n = 146). Genotype frequency in controls was not significantly different from area to area in Japan. In Okinawa, however, the genotype encoding Val/Val was associated with a significantly higher risk of lung cancer (odds ratio = 3.32, P = 0.013), especially of squamous cell carcinoma and small cell carcinoma (odds ratio = 4.85 and 9.35, respectively). The Val-encoding allele was less frequent in the Chinese population and was rare in Australian Caucasians. Thus, this study gives support to the value of the cytochrome P450 IA1 Ile462Val polymorphism as a practical high-risk marker of lung cancer in populations, especially those in southeast Asia, in which this variant is more common.

[A FISH technique for simultaneous detection of fluorescent R-band and in situ hybridization signals]

OBJECTIVE

To develop a simple method for detecting DNA probes directly on R-banded chromosomes.

METHODS

After sixty-seven hours culture, human peripheral blood lymphocytes were synchronized for 5 to 6 hours by adding Hoechst 33258 and BUdR, and then arrested by standard cytogenetic procedures. The slides were mounted with 2 x SSC and exposed with a 20W UV light which was about 10cm above the slides for 20 min at 75 degrees C. The biotinylated probes, such as the cosmid and YAC clones on 5p specific region and pBamX7, were hybridized on to the slides. After washing, the slides were treated with avidin-FITC and amplified with additional layer of biotinylated anti-avidin and avidin-FITC, and counterstained with propidium iodide in an antifade solution. Fluorescent signals and R-bands were observed simultaneously under Olympus BX 60 fluorescence microscope equipped with a WIB filter.

RESULTS

The chromosomal location of the greenish-yellow signals could be directly identified on the R-banded chromosome background.

CONCLUSION

This method can serve as a rapid and precise system for chromosomal localization of DNA markers.

An antibody exo Diels-Alderase inhibitor complex at 1.95 angstrom resolution

A highly specific Diels-Alder protein catalyst was made by manipulating the antibody repertoire of the immune system. The catalytic antibody 13G5 catalyzes a disfavored exo Diels-Alder transformation in a reaction for which there is no natural enzyme counterpart and that yields a single regioisomer in high enantiomeric excess. The crystal structure of the antibody Fab in complex with a ferrocenyl inhibitor containing the essential haptenic core that elicited 13G5 was determined at 1.95 angstrom resolution. Three key antibody residues appear to be responsible for the observed catalysis and product control. Tyrosine-L36 acts as a Lewis acid activating the dienophile for nucleophilic attack, and asparagine-L91 and aspartic acid-H50 form hydrogen bonds to the carboxylate side chain that substitutes for the carbamate diene substrate. This hydrogen-bonding scheme leads to rate acceleration and also pronounced stereoselectivity. Docking experiments with the four possible ortho transition states of the reaction explain the specific exo effect and suggest that the (3R,4R)-exo stereoisomer is the preferred product.

Identification of a blue photoluminescent composite material from a combinatorial library

A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd3Ga5O12/SiO2. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO2 and Gd3Ga5O12.

Use of a reverse transcriptase-polymerase chain reaction assay to analyze allele-specific expression in individual hippocampal neurons

We report here a single-cell RT-PCR assay for allele-specific gene expression that can be used to probe for somatic variability within the CNS. Such variability, arising from epigenetic (nonmutational) events or somatic mutation early in development, may give clues as to clonal origin and may also affect the inheritance pattern of some CNS disorders. As a model system, we used reciprocal F1 hybrids of the cross Mus musculus C57BL/6J x Mus musculus castaneus. RNA was isolated from individual dissociated pyramidal neurons from hippocampi of F1 pups. For each gene of interest, single base polymorphisms were identified between the two parental strains by automated sequencing of RT-PCR products. Allele-specific expression was then analyzed by means of the previously described quantitative RT-PCR single nucleotide primer extension (SNuPE) assay (Singer-Sam et al., PCR Methods Appl. 1:160-163, 1992). Individual neurons showed monoallelic expression of the two control genes, X-linked Rps4, and the imprinted gene Snrpn; in contrast expression of Ncam and F3cam, coding for neural cell adhesion molecules, was found to be biallelic.

Transient activation of cyclin B/Cdc2 during terminal differentiation of lens fiber cells

Previous work has shown that postmitotic, differentiating fiber cells of the embryonic chicken lens express cyclin B and Cdc2. The present study explores the possible physiological role of these proteins in lens differentiation by examining the developmental regulation of cyclin B/Cdc2 expression and activity in lens fiber cells of embryonic and newborn rats. Cyclin B mRNA and protein were detected not only in the lens epithelium, which contains proliferating cells, but also in postmitotic, differentiating fiber cells. In contrast, cyclin A mRNA and protein were detected only in epithelial cells. Immunoprecipitation with cyclin B antibody coprecipitated Cdc2 from both epithelial and fiber cell extracts. Immunoprecipitates of cyclin B from both epithelial cells and fiber cells showed H1 kinase activity when assayed in vitro, but the developmental pattern of cyclin B-associated kinase activity in these two lens fractions was markedly different. In the epithelium, H1 kinase activity decreased gradually with developmental age in parallel with the decrease in epithelial cell proliferation, whereas, in the fiber cells, kinase activity peaked sharply at embryonic day 18 (E18) and E19. Microscopic examination of rat lenses indicated that peak cyclin B/Cdc2 activity was correlated with changes in chromatin structure and nuclear envelope breakdown in the terminally differentiating primary lens fiber cells. These findings suggest that cyclin B/Cdc2 activity may play an active role in nuclear changes leading to primary fiber cell denucleation.

Dissociation of cytokine signals for proliferation and apoptosis

Cytokines such as IL-2 or IL-3 prevent cell death through apoptosis, either by preventing apoptosis directly or by sensitizing cells to survival factors present in serum. We demonstrate herein that BAF-B03 cells transfected with the wild-type IL-2R beta-chain undergo apoptosis when stimulated with IL-2 or IL-3 in the absence of serum. IL-2 also induced apoptosis in normal IL-2-responsive human T cell blasts in the absence of serum, and furthermore, epidermal growth factor and fibroblast growth factor induced increased rates of apoptosis in fibroblasts in the absence of serum, suggesting that cytokine-induced apoptosis in the absence of serum survival factors might represent an important biologic phenomenon. In the presence or the absence of serum, IL-2 and IL-3 induced expression of both c-Myc and Bax. In contrast, optimal cytokine-induced expression of Bcl-2 requires serum. Constitutive expression of Bcl-2 prevented cytokine-induced apoptosis. Transferrin mimicked serum by inducing an increase in Bcl-2 expression levels and concurrently prevented apoptosis. These results suggest that the balance between cytokine- and serum-induced Bcl-2 expression and cytokine-induced Bax expression may determine whether a cell undergoes cytokine-induced apoptosis. In BAF/BO3 cells expressing a mutant IL-2Rbeta with a deletion of the acidic domain, IL-2 did not induce either Bax expression or apoptosis. This suggests that the acidic domain of the IL-2R beta-chain plays an essential role in regulating IL-2-mediated Bax expression and apoptosis. Cytokine-induced apoptosis and its counterbalance by survival factors present in serum may play an important role in the regulation of cellular homeostasis during pathophysiologic processes.

The biological effects of antisense mos expression in fibroblasts

In order to determine the physiological significance of c-mos RNA expression in somatic cells, we introduced antisense c-mos under the control of an inducible promoter. NIH/3T3 cells were stably transfected with antisense mos under the control of the mouse mammary tumor virus long terminal repeat (MMTV-LTR). Positive transfectants were selected under G418 conditions. Following selection, NIH/3T3 cells that received the antisense mos failed to form foci, whereas sense mos transfected cells grew normally. Moreover, v-mos-transformed cells were unaffected by antisense mos transfection. Of: interest, NIH/3T3 antisense mos transfectants that survived selection were growth-arrested. Nuclear abnormalities and the extrusion of microvesicles containing cellular material were observed in these cells. In order to rescue these cells from growth inhibition, the v-mos gene was introduced into cells by acute infection with Moloney murine sarcoma virus. Following infection, these cells resumed growth and became rapidly transformed. In other experiments, mouse C2 cells stably transfected with antisense mos showed a slower growth rate and gross morphological changes. C2 cells containing antisense mos under the control of mouse metallothionein-1 promoter had a large and flattened morphology and a relatively high percentage (30%) of binucleated cells. Our results indicate that basal level expression of antisense mos (under uninduced conditions) results in either arrested or retarded cell growth. The phenotypes exhibited in both cell lines leads us to suggest that the c-mos expression may play a role in mitotic progression in some somatic cells, in particular affecting cytokinesis.

Dissociation of cytokine signals for proliferation and apoptosis

Cytokines such as IL-2 or IL-3 prevent cell death through apoptosis, either by preventing apoptosis directly or by sensitizing cells to survival factors present in serum. We demonstrate herein that BAF-B03 cells transfected with the wild-type IL-2R beta-chain undergo apoptosis when stimulated with IL-2 or IL-3 in the absence of serum. IL-2 also induced apoptosis in normal IL-2-responsive human T cell blasts in the absence of serum, and furthermore, epidermal growth factor and fibroblast growth factor induced increased rates of apoptosis in fibroblasts in the absence of serum, suggesting that cytokine-induced apoptosis in the absence of serum survival factors might represent an important biologic phenomenon. In the presence or the absence of serum, IL-2 and IL-3 induced expression of both c-Myc and Bax. In contrast, optimal cytokine-induced expression of Bcl-2 requires serum. Constitutive expression of Bcl-2 prevented cytokine-induced apoptosis. Transferrin mimicked serum by inducing an increase in Bcl-2 expression levels and concurrently prevented apoptosis. These results suggest that the balance between cytokine- and serum-induced Bcl-2 expression and cytokine-induced Bax expression may determine whether a cell undergoes cytokine-induced apoptosis. In BAF/BO3 cells expressing a mutant IL-2Rbeta with a deletion of the acidic domain, IL-2 did not induce either Bax expression or apoptosis. This suggests that the acidic domain of the IL-2R beta-chain plays an essential role in regulating IL-2-mediated Bax expression and apoptosis. Cytokine-induced apoptosis and its counterbalance by survival factors present in serum may play an important role in the regulation of cellular homeostasis during pathophysiologic processes.

Making chemistry selectable by linking it to infectivity

The link between recognition and replication is fundamental to the operation of the immune system. In recent years, modeling this process in a format of phage-display combinatorial libraries has afforded a powerful tool for obtaining valuable antibodies. However, the ability to readily select and isolate rare catalysts would expand the scope of library technology. A technique in which phage infection controlled the link between recognition and replication was applied to show that chemistry is a selectable process. An antibody that operated by covalent catalysis to form an acyl intermediate restored phage infectivity and allowed selection from a library in which the catalyst constituted 1 in 10(5) members. Three different selection approaches were examined for their convenience and generality. Incorporating these protocols together with well known affinity labels and mechanism-based inactivators should allow the procurement of a wide range of novel catalytic antibodies.

Risk factors for human cysticercosis morbidity: a population-based case-control study

A population-based case-control study to determine social and behavioural risk factors for Taenia solium cysticercosis in humans was carried out in a rural area. Shandong province, China. Forty-eight cases with cysticercosis were ascertained through a prevalence survey conducted among 7281 persons in 1993. For each case, four controls residing in the same village and matched for age and sex were randomly selected. Information regarding demographic, social and behavioural factors was collected during house visits through interviews and direct observation. Risk factors strongly associated with human cysticercosis included poor personal hygiene, being unable to recognize cysticerci-containing meat, poor pig-raising practices and a history of passing tapeworm proglottides. The results indicate that health education in combination with chemotherapy for taeniasis is required for the control of cysticercosis in humans.

Immortalization of mutant p53-transfected human fibroblasts by treatment with either 4-nitroquinoline 1-oxide or X-rays

The study of in vitro cell transformation is valuable for understanding the multistep carcinogenesis of human cells. The difficulty in inducing neoplastic transformation of human cells by treatment with chemical or physical agents alone is due to the difficulty in immortalizing normal human cells. Thus, the immortalization step is critical for in vitro neoplastic transformation of human cells. We transfected a mutant p53 gene (mp53: codon 273Arg-His) into normal human fibroblasts and obtained two G418-resistant mp53-containing clones. These clones showed an extended life span but ultimately senesced. However, when they were treated with either 4-nitroquinoline 1-oxide or X-rays, they were immortalized. The immortalized cells showed both numerical and structural chromosome abnormalities, but they were not tumorigenic. The expression of mutant but not wild type p53 was detected in the immortalized cells by RT-PCR. Expression of p21, which is located downstream of p53, was remarkably reduced in the immortalized cells, resulting in increased cdk2 and cdc2 kinase activity. However, there was no significant difference between the normal and immortalized human cells in expression of another tumor suppressor gene, p16. These findings indicate that the p53-p21 cascade may play an important role in the immortalization of human cells.

Transformation of normal human fibroblasts into immortalized cells with the mutant p53 gene and X-rays

In vitro cell transformation is a valuable approach for studying the mechanisms of multistep carcinogenesis of human cells. Since immortalization is an essential step for in vitro neoplastic transformation of human cells, this study addresses the question of whether mutant p53 contributes to the immortalization process of human cells. The mutant p53 gene (mp53: codon273Arg-His) was introduced into normal human fibroblasts (OUMS-24 line) and a G418-resistant clone, OUMS-24/P6 line, was obtained. This clone showed an extended life span and chromosome abnormalities, but senesced at the 79th population doubling level (PDL). When these cells were subjected to intermittent X-ray treatment, they became an immortalized cell line (OUMS-24/P6X). Although these immortalized cells showed chromosome abnormalities, they were not tumorigenic. On the other hand, normal OUMS-24 cells into which mp53 had not been introduced were not immortalized by the same X-ray treatment. These results indicate that introduction and expression of mp53 alone were not sufficient for immortalization of human cells, and that mutations of the remaining wild-type p53 or other genes may have been necessary for immortalization. In fact, no expression of the wild-type p53 was detected in the immortalized cells by RT-PCR. Expression of p21, which is located downstream of p53, was remarkably reduced in the immortalized cells, resulting in an increase in cdk2 and cdc2 kinase activity. These findings indicate that the p53-p21 cascade may play some role in the immortalization of human cells. On the other hand, there was no significant difference in expression of proteins such as Rb, p16, cdk4, cdk6, cyclin A and cyclin D1 between the normal and immortalized human fibroblasts.

Some design recommendations to improve comfort in helmets: a case study from China

Unless the basic user needs are satisfied in safety helmets, it is difficult to get workers to wear them habitually and for long periods. Hotness, weight and fitting problems are major wearability issues that require improvements. The enormous need for an optimally designed helmet in China prompted a case study on comfort aspects in helmets. The subjective impressions of the wearers of test helmets provided useful information for design changes to improve comfort. The heat transfer measurements through helmets indicated the need for ventilation openings to be provided on the shell of plastic helmets. Due to the advantage of low weight and good ventilation, it is recommended that cane helmets be further developed to improve protection, wearability and durability, and subsequently be produced in large scale.

Portal branch occlusion safely facilitates in vivo retroviral vector transduction of rat liver

Hepatic gene therapy might correct the clinical manifestations of several genetic disorders in patients. Although retroviral vectors with a strong liver-specific promoter can result in stable and therapeutic levels of expression of genes from the liver, application of these techniques in humans is limited by the need to perform one or more invasive procedures to achieve ex vivo or in vivo transduction of hepatocytes. In vivo delivery involves injection of retrovirus into the portal vein during liver regeneration. Although transduction is efficient and specific for the liver, induction of hepatocyte replication requires a 70% partial hepatectomy or administration of a liver toxin. An alternative method for inducing hepatocyte replication is to occlude branches of the portal vein. This results in apoptosis of hepatocytes in the occluded lobes and compensatory replication of the hepatocytes in the nonoccluded lobes. We demonstrate here that portal branch occlusion is nearly as effective as partial hepatectomy at facilitating retroviral vector transduction in vivo and has a lower morbidity. Portal branch occlusion could be performed in larger animals by minimally invasive techniques and has been used safely to treat human patients with liver cancer. Portal branch occlusion might ultimately be used in humans to facilitate retroviral vector transduction in vivo for the treatment of genetic diseases.

[Retroviral-mediated transfer of beta-globin gene into human hematopoietic cells]

Transferring beta-globin gene and its enhancer into human hematopoietic cells is the basis for applying beta-thalassemia gene therapy in clinical practice. We isolated ecotropic virus producing clones and amphotropic virus producing clones by using a replication-defective retrovirus vector containing beta-globin gene and its enhancer to transfect ecotropic packaging cell line phi-2 and amphotropic packaging cell line PA317. Then by ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, we obtained high titer amphotropic PA317 producer clones with the highest titer up to 5.9 x 10(6) CFU/ml. Human mononuclear bone marrow cells were infected repeatly with this high titer virus vector under stimulation of hematopoietic growth factors IL-3, IL-6 and SCF, Southern blot hybridization analysis showed that beta-globin gene and its enhancer had been integrated into the genome of human hematopoietic cells.

[Correlation of multiple gene changes with malignant phenotype of human gastric carcinoma]

OBJECTIVE

To investigate the alteration of oncogenes and tumor suppressor genes in gastric carcinogenesis.

METHODS

Southern blot, PCR/SSCP and DNA sequencing techniques were used in 33 gastric carcinomas to detect c-met, EGFR, c-erbB-2, AKT-2, c-Ha-ras, p53, p16 and nm23-H1, for the presence of amplification, deletion, mutation and rearrangement.

RESULTS

Most tumors (70%) haboured one or more altered genes. The number and type of gene alteration were different among individuals. Rearrangement of c-met was noted in 2/33 cases (6%), and amplification of c-met, c-erbB-2 and AKT-2 in 8/33 cases (24.2%), 1/33 cases (3%) and 2/18 cases (11%) respectively. Homozygous deletion of P16 was seen in 6/33 cases (18%). Loss of heterozygousity was also noted in nm23-H1 5/17 (29%) and p53 2/13 (16%). The mutation rate of p53 in exon 5-8 was 20/33 (61%). Point mutation of p53 was found at both early and advanced tumors. In contrast, amplification of oncogenes and loss of tumor suppressor genes were correlated with poorly differentiated and metastatic tumors.

CONCLUSIONS

Gastric carcinogenesis is a gradually developed process, results from sequencial alteration of multigenes. The malignant phenotype is associated with the degree of genetic abnormality.

Transforming growth factor beta (TGF-beta) expression in isolated and cultured rat hepatocytes

It is still a subject of debate whether hepatocytes have the ability to express TGF-beta. Therefore, we investigated in freshly isolated and in monolayer cultures of rat hepatocytes the expression of TGF-beta isoform s at the RNA and protein level applying RT-PCR, immunocytochemistry, immunoblotting, and functional assays of TGF-beta. TFG-beta 1, -beta 2, and -beta 3 transcripts were detected in cultured cells, and the level of m RNA increased up to 48/72 h, but TGF-beta 1 transcripts were absent in freshly isolated cells. Using APAAP stainings the proteins of all three TGF-beta isoforms were observed in hepatocyte cultures from 5-96 h, but in hepatocytes in the liver in situ and in freshly isolated cell suspensions TGF-beta staining was negative. SDS-PAGE under reducing conditions followed by Western blotting detected in cell lysates the subunit of mature TGF-beta at about 13 kd. Analysis of TGF-beta bioactivity with the mink cell (Mv1Lu) proliferation inhibition assay and competitive radioligand assay confirmed in activated (i.e., acidified and subsequently neutralized) hepatocyte-conditioned media the presence of TGF-beta, which, however, is almost entirely in the latent form. It is concluded that TGF-beta can be expressed in cultured hepatocytes and that the level of expression is quickly upregulated under abnormal, not yet known, microenvironmental conditions.

The effects of 5-hydroxydopamine on salivary flow rates and protein secretion by the submandibular and parotid glands of rats

The secretory effects of 5-hydroxydopamine (5-OHDA) were tested in Nembutal-anaesthetized adult male Sprague-Dawley rats injected I.V. over a wide range of doses, with and without various autonomic antagonists and Ca2+ channel blockers. Polyacrylamide disc gel (15%) and iso-electric focusing (IEF) electrophoresis by the PhastSystem were used to separate and determine the types of protein in submandibular saliva. Amylase activity of parotid saliva was determined by the blue dextran method. Salivation by the submandibular glands following application of 5-OHDA was completely abolished by both prazosin and propranolol, whereas salivation by the parotid glands was completely abolished by propranolol alone. Following application of 5-OHDA, there was a dose-related increase in flow rates and total output of protein, but not in the protein concentration and amylase activity, from both salivary glands. The effect of 5-OHDA on submandibular saliva was significantly reduced by alpha-adrenoceptor blockers, but not by beta-adrenoceptor and cholinergic blockers, nor by any Ca2+ channel blocker. The effect of 5-OHDA on the parotid gland was not significantly altered by atropine and phentolamine. However, after pretreatment with reserpine, a 95% reduction was observed in the salivation from the submandibular gland. This implies that 5-OHDA is mostly acting indirectly via release of noradrenaline. The proteins in submandibular saliva following treatment with 5-OHDA alone or 5-OHDA in combination with beta-adrenoceptor blockers were mainly of the alpha-type, whereas after treatment with 5-OHDA in combination with alpha-adrenoceptor blockers they were of the beta-type. The alpha-type was found in saliva after treatment with each of three Ca2+ channel blockers.

Transforming growth factor beta (TGF-beta) expression in isolated and cultured rat hepatocytes

It is still a subject of debate whether hepatocytes have the ability to express TGF-beta. Therefore, we investigated in freshly isolated and in monolayer cultures of rat hepatocytes the expression of TGF-beta isoform s at the RNA and protein level applying RT-PCR, immunocytochemistry, immunoblotting, and functional assays of TGF-beta. TFG-beta 1, -beta 2, and -beta 3 transcripts were detected in cultured cells, and the level of m RNA increased up to 48/72 h, but TGF-beta 1 transcripts were absent in freshly isolated cells. Using APAAP stainings the proteins of all three TGF-beta isoforms were observed in hepatocyte cultures from 5-96 h, but in hepatocytes in the liver in situ and in freshly isolated cell suspensions TGF-beta staining was negative. SDS-PAGE under reducing conditions followed by Western blotting detected in cell lysates the subunit of mature TGF-beta at about 13 kd. Analysis of TGF-beta bioactivity with the mink cell (Mv1Lu) proliferation inhibition assay and competitive radioligand assay confirmed in activated (i.e., acidified and subsequently neutralized) hepatocyte-conditioned media the presence of TGF-beta, which, however, is almost entirely in the latent form. It is concluded that TGF-beta can be expressed in cultured hepatocytes and that the level of expression is quickly upregulated under abnormal, not yet known, microenvironmental conditions.

[Deletion and down-regulation of mts1/p16 gene in human gastric cancer]

Deletion of mts1/p16 gene was frequently detected in many human tumor cell lines. However, whether alteration of the p16 gene was involved in human gastric carcinogenesis, it is not clear. In order to determine the incidence and correlation of the p16 gene deletion with human gastric cancer, we performed analyses of PCR, Southern and Northern blotting on 85 fresh tumor specimens and 5 tumor cell lines from gastric cancer patients. Homozygous deletion was observed in 1 cell line and down-regulation of expression was observed in 3. High rate of gene deletion was detected by PCR in 14 of 85 fresh tumor tissues. Gene deletion was confirmed by Southern blot analysis with p16 cDNA probe in 6 out of 26 tumor specimens examined.

Further characterization of the c-mos transcript and its cell cycle specific expression in NIH3T3 cells

The mouse c-mos proto-oncogene is primarily expressed in germ cells. Our previous studies demonstrated c-mos RNA expression in mouse somatic cells, with the highest level present in the G2 phase of the cell cycle (Tsui et al., 1993). We have identified the transcription start site of this G2 specific c-mos transcript to be located about 1580 bp upstream from the open reading frame based on RT-PCR and RNase protection experiments. Upstream sequences containing this transcription start site directed highest expression of the luciferase reporter gene in M phase of the cell cycle. These results suggest that c-mos transcripts are produced in G2 phase and that c-Mos protein albeit at extremely low levels would accumulate in M phase.

The N-methyl-D-aspartate-mediated inhibitory control of gonadotropin-releasing hormone release in the hypothalamus of the adult male guinea pig is expressed through opioidergic systems

Previously, we reported on a dual role of N-methyl-D-aspartate (NMDA) receptor-mediated neurotransmission in the control of GnRH secretion from the medial basal hypothalamus (MBH) of the adult male guinea pig, with a predominantly inhibitory action in the intact animal, which is reversed to a facilitatory role by orchidectomy. In the present study we examined the hypothesis that endogenous opioids are involved in the NMDA receptor-mediated inhibition of GnRH release. A static incubation system was used to test the effects of excitatory amino acid agonists and an excitatory amino acid antagonist, alone or in the presence of either the opiate agonist morphine or the mu-receptor antagonist naloxone, on in vitro GnRH release from the isolated MBH of intact, orchidectomized, or sham-operated guinea pigs. GnRH output from the MBH of intact guinea pigs was markedly suppressed in the presence of the NMDA-specific receptor agonist, N-methyl-D,L-aspartic acid (NMA; 50 mM), whereas NMDA-specific receptor blockade with D,L-amino-5-phosphonovaleric acid (AP-5; 1 mM) resulted in a pronounced facilitation of GnRH release, as did exposure to the non-NMDA-specific receptor agonist, kainic acid (50 mM). Opioidergic blockade with naloxone (1 mM) caused a reversal of the responses to NMA and AP-5, with exposure to these compounds this time resulting in clear facilitation and inhibition, respectively. The stimulatory action of kainic acid, on the other hand, remained unaffected by the presence of naloxone. Morphine inhibited basal GnRH output and also annulled the stimulatory effect of AP-5 on GnRH secretion. The results obtained from MBHs of sham-operated guinea pigs were identical to those seen for the intact animals, with naloxone effectively increasing baseline GnRH release and reversing the inhibitory effect of NMA and stimulatory action of AP-5 on GnRH secretion to a facilitation and inhibition, respectively. On the other hand, NMA caused a marked stimulation, whereas AP-5 produced a significant inhibition of GnRH release from the MBHs of orchidectomized guinea pigs; neither of these effects was altered by the presence of naloxone, which, moreover, had only a marginal effect on basal GnRH output in this group of animals. In conclusion, our present data provide evidence to support the view that the primary inhibitory action of NMDA receptor-mediated neurotransmission on GnRH release in the MBH of the intact male guinea pig is the result of activation of opioidergic systems and that a marked reduction of opioid tone after orchidectomy brings a facilitatory NMDA receptor-mediated system to the fore. On the other hand, non-NMDA-specific kainate receptor-mediated facilitation of GnRH, previously shown to be unaffected by gonadal status, appears to be also independent from opioidergic modulation.

[K562 cells differentiation induced by RNA from rabbit reticulocytes]

OBJECTIVE

To study the effect of RNA from the reticulocytes of rabbit on cell differentiation of human leukemia cell line K562 cells.

METHOD

RNA from rabbit reticulocytes and human leukemia K562 cells were cultured for 4 days to detect cellular changes.

RESULTS

When K562 cells grew in a medium containing 100 micrograms/ml RNA, the cellular growth and division were gradually suppressed and the cells changed toward a differentiated phenotype. Subsequently, K562 cells produced hemoglobins and further differentiated terminally.

CONCLUSION

RNA of mammalian erythrocyte played a role in declining cellular division and growth of K562 cells, reversing malignant phenotype, and promoting differentiation.

Subpopulations of migrating neurons express different levels of LHRH in quail and chick embryos

LHRH neurons of the septal-preoptic area originate in the olfactory placode and migrate in the olfactory nerve into the brain during embryonic development. In adult birds, LHRH neurons have been found in the septal-preoptic area, mesencephalon and more recently in the lateral anterior nucleus of the thalamus (LA). LHRH neurons of the LA do not originate in the olfactory placode. Using immunocytochemistry, we examined the distribution of LHRH neurons in the embryonic and adult quail nervous system. The pattern of LHRH immunostaining in quail embryos was similar to that seen in chick embryos. However, there were many fewer neurons immunostained for LHRH from the olfactory placode to the septal-preoptic area in quail than in chick embryos. In contrast, there were more labeled neurons and more intense LHRH immunostaining in the thalamus of the quail than in the thalamus of chick embryos. In agreement with other studies, our data suggest that there are species differences in LHRH expression in migrating neurons. The current results should also be considered for quail-chick chimeras involving the olfactory placode.

Tangential migration of luteinizing hormone-releasing hormone (LHRH) neurons in the medial telencephalon in association with transient axons extending from the olfactory nerve

During embryonic development, luteinizing hormone-releasing hormone (LHRH) neurons migrate to the brain from the medial olfactory epithelium through the olfactory nerve. LHRH neurons enter the brain and migrate tangentially along the medial edge of the telencephalon in close association with a neural cell adhesion molecule (N-CAM) enriched fiber bundle. In the current work we wished to determine whether this N-CAM enriched fiber bundle is an extension of the olfactory nerve. Ablation experiments, immunocytochemistry and diI implants all suggest that LHRH neurons migrate in association with a very small subset of transient N-CAM enriched neuronal processes which extend out of the olfactory nerve proper to the septal-preoptic area.

[Inclusion compounds of jiuxin oil with beta-cyclodextrin]

The inclusion compounds of Jiuxin Oil with beta-cyclodextrin were prepared. The influence of temperature, ratio of host and guest molecules, stirring time on inclusion were observed. The quantitative determination was performed by gas chromatography. Inclusion compounds of Jiuxin Oil were confirmed by differential scanning calorimetry and powder X-ray diffractometry.

[The diagnosis and treatment of benign esophagotracheo-bronchial fistula: a report of 26 cases]

Twenty six patients with esophagotracheal fistula or esophagobronchial fistula were treated from 1960 to 1991. There were 18 males and 8 females with age ranging from 19 to 69. Trauma and complication of esophageal diverticulum were the main causes of fistula. Among 23 patients surgically treated, 10 underwent direct repair, and 13 either closure of esophageal defect or tracheal or bronchial defect. The concomitant procedures were permanent tracheostomy, tracheal resection and reconstruction, pulmonary resection, thoracoplasty esophagectomy, and esophagogastric anastomosis. All patients resumed normal eating. Complications included paralysis of recurrent nerves, empyema, injury and ligation of subclavian artery, dehiscence of tracheal anastomosis, and contralateral pneumohydrothorax in each patient. Prognosis of 3 nonsurgical treatments of fistulas was poor. Surgical intervention should be done as soon as the diagnosis is established in order to minimize pulmonary complication.

LHRH neuronal subtypes have multiple origins in chickens

Previous studies indicate that LHRH neurons of the septal-preoptic area originate in the olfactory epithelium. In the current study, we found that LHRH neurons entering the telencephalon from the olfactory nerve were not continuous with LHRH neurons in the thalamus. In addition, ablation of the olfactory placode eliminated LHRH neurons in the telencephalon but did not eliminate LHRH neurons in the thalamus. We propose that there are at least two sites of LHRH neuron production, the olfactory epithelium and the diencephalon.

[Case report of pulmonary histoplasmosis]

A case of pulmonary histoplasmosis in Beijing was reported Patient's CT scan showed naly patchy consolidation partly with small cavitations and hilar silhouette enlarged in both lungs. On pathologic examination, Histoplasma Capsutatums were found in the lung tissures by percutaneous lung biopsy. Skin rash had developed in the course. After treated by fluconaxole, most of the lung lesions and skin rash disappeared.