[Study on psychoprophylaxis and monoamines neurotransmitter of patients with burning mouth syndrome]

OBJECTIVE

Burning mouth syndrome (BMS) is a chronic ache disease, usually occurring in middle aged and old women. This study sought to understand the psychopathologic aspect and monoamines neurotransmitters in the plasma of the patients with BMS.

METHODS

Thirty cases were selected (26 females, 4 males); 30 normal control subjects were similar to the BMS cases on age and sex. All subjects were required to complete the Eysenck personality questionnaire (EPQ), and the Self-report Symptom Inventory, Symptom Check List-90 (SCL-90) questionnaire. In case a subject's L (lie) score exceeded 50, she (he) would be removed from the test. 2 ml of blood was drawn from the subject under restine conditions with a fast in the morning to examine norepinephrine and epinephrine contents by high efficient liquid chromatography. Chi-square test, analysis of variance and t'-test were performed.

RESULTS

The BMS group had higher scores of nervousness (N) and poikilergasia (P) and lower score of extro/introversion (E) as compared with the control (P < 0.05). The personality types in BMS group were focused on introversion and instability, but in the control group the types were focused on extroversion and stability (P < 0.05). The scores of 9 emotional factors of BMS group were significantly higher than those of the control group (P < 0.05), which indicated that the BMS patients had suffered from serial psychic disorders. The level of plasma norepinephrine in the BMS patients was higher than that of the control (P < 0.01).

CONCLUSION

The personality of BMS patients raised body response to harmful stimulations, and obvious psychic disorders in the patient may cause the functional disorders in central and sympathetic nervous systems, which may be associated with BMS' occurrence.

Transforming growth factor-alpha promotes mouse blastocyst outgrowth and secretion of matrix metalloproteinases

OBJECTIVE

To study the effect of transforming growth factor-alpha (TGF-alpha) on early stage of embryo implantation.

METHODS

Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-alpha. Blastocyst implantation capacity was evaluated by calculating the percentage of embryos with attachment or outgrowth. Matrix metalloproteinases (MMPs) secretion of blastocysts was observed using gelatin zymography.

RESULTS

There was no significant difference in the percentage of attachment between control and TGF-alpha treated groups, but the percentage of outgrowth of TGF-alpha treated groups was significantly higher than that of the control group after 24 h culturing. Gelatin zymography showed that blastocysts cultured in TGF-alpha treated groups started secreting MMPs earlier than those in the control group.

CONCLUSION

TGF-alpha is involved in regulating the mouse embryo implantation process by promoting blastocyst outgrowth and secreting matrix matalloproteinases.

Film dosimetric verification of the Voxel Monte Carlo (VMC) algorithm with electron beam dose distributions

Monte Carlo (MC) methods have the potential to predict radiation-therapy doses more accurately than any conventional technique, but normal MC simulations are very time consuming. Therefore, a fast MC code (Voxel Monte Carlo; VMC) was developed especially for radiation therapy purposes and experiments with the comparable precision were performed to demonstrate its accuracy. In the present study the dose distributions measured with film dosimetry in a cylindrical phantom were compared with calculations derived by VMC. The phantom consisted of 18 circular shaped PMMA slabs with a diameter of 20 cm and a thickness of approx. 1 cm. The films were placed between the slabs, and the whole phantom was irradiated with electron beams of different energies (6 MeV, 10 MeV, 18 MeV). The measured optical density distributions were then converted into dose distributions using characteristic curves of the film. Taking into account experimental uncertainties and statistical calculation fluctuations, agreement was found between measurements and VMC simulations with a maximal deviation of 3 mm on isodose curves for 18 MeV.

[Methodological studies on the evaluation of family burden due to injuries]

OBJECTIVE

To evaluate the method for describing the burden and dimensions of injury on family.

METHODS

Eighty-four families of patients with injury from the selected families were studied. Status on family function, including before and after the suffering disease, were measured with Family APGAR index. Present family function was re-measured one week after the initial study. The burden of injury on these families was measured with Family Burden Score.

RESULTS

There were significant differences (P < 0.01) between scores of APGAR before and after the onset of injury. Forty-one point six seven percent of the families were with dysfunctions prior to the injuries, while 89.29% of families having dysfunctions for the time being. There were universal burden on the families of patients with injury in multi-dimensions, including economic status, routine life, entertainment, relationship between members, physiological and psychological health of the members, and social relationship of and within the families.

CONCLUSION

Injury may bring impacts to the patient's family in multi-dimensions and induce dysfunction to patient's family. Both patients and their families should be involved when providing health care to and evaluating burden of injury on them.

[Effects of microwave radiation on the content of five elements in mice bone tissue]

Mice were radiated with 2450 MHz, 10 mW/cm2 microwave for 12 days, 1.5 h/day. After microwave radiation, compared with the normal control, the content of calcium and zinc in mice bone were significantly decreased (P < 0.05) copper, iron and manganese decreased, appulsively After Libido, a composed traditional herb medicine, and asshide asafetida were supplied seperatively, the content of calcium and trace element zinc in mice bone increased (P < 0.05). It is concluded that Libido was effective on the resistance of mice to microwave radiation. The toxicity of organotin compounds and the current pollution status.

[Impact of extracellular gene of VEGF receptor KDR on growth of human bladder carcinoma in nude rats]

OBJECTIVE

To investigate the anti-angiogenesis activity of the extracellular domain of vascular endothelial growth factor (VEGF) receptor KDR.

METHODS

The eukaryotic expression plasmid pcDNA3.1/KDR(n7) of the extracellular domain of KDR was transfected into the human bladder carcinoma EJ cells by lipofactamin technology. Cellular clone that stably expressed the target protein was obtained by G418 screening. The cellular clone that expressed the target protein specifically combined with VEGF was obtained by solid-phase binding assay. The positive cellular clone was identified by RT-PCR.

RESULTS

The rKDR(n7) expressed by EJ cells can inhibit the angiogenesis in egg CAM. The EJ cell strain significantly inhibits the growth and angiogenesis of human bladder carcinoma in nude rat. The microvascular density in the experimental group was 12 +/- 4, significantly lower than that in hte negative control group (62 +/- 11).

CONCLUSION

Inhibition of the VEGF/KDR signal transmission channel can inhibit the angiogenesis in tumor, thus delaying its growth.

MHC class II-restricted tumor antigens recognized by CD4+ T cells: new strategies for cancer vaccine design

The adoptive transfer of tumor-infiltrating lymphocytes (TIL) can mediate tumor regression in patients with melanoma. This finding has led to the identification and characterization of tumor-associated antigens recognized by CD8+ TIL. Several clinical trials based on the genes recognized by these CD8+ T cells have been attempted, but with only limited success. Meanwhile, increasing evidence has demonstrated that CD4+ T cells play important roles in generating and maintaining antitumor immune responses in animal models. These data suggest that it may be necessary to engage both CD4+ and CD8+ T cells for more effective antitumor immunotherapy. In this report, we review emerging molecular approaches in cloning major histocompatibility complex (MHC) class II restricted tumor antigens recognized by CD4+ T cells as well as approaches to identify new MHC class II-restricted epitopes from known tumor antigens recognized by CD8+ cytotoxic T lymphocytes and/or antibodies. Progress made in this field has shed light on the roles of tumor antigen-specific CD4+ T cells in humans; it has also provided new insights into the understanding of tumor genesis and the interaction between tumor and the immune system. More importantly, the discovery of MHC class II-restricted tumor antigens has provided opportunities for developing a new generation of cancer vaccines aimed at eliciting both CD4+ and CD8+ T-cell responses against tumor.

CD4(+) T cell recognition of MHC class II-restricted epitopes from NY-ESO-1 presented by a prevalent HLA DP4 allele: association with NY-ESO-1 antibody production

NY-ESO-1 is a tumor-specific shared antigen with distinctive immunogenicity. Both CD8(+) T cells and class-switched Ab responses have been detected from patients with cancer. In this study, a CD4(+) T cell line was generated from peripheral blood mononuclear cells of a melanoma patient and was shown to recognize NY-ESO-1 peptides presented by HLA-DP4, a dominant MHC class II allele expressed in 43--70% of Caucasians. The ESO p157--170 peptide containing the core region of DP4-restricted T cell epitope was present in a number of tumor cell lines tested and found to be recognized by both CD4(+) T cells as well as HLA-A2-restricted CD8(+) T cells. Thus, the ESO p157--170 epitope represents a potential candidate for cancer vaccines aimed at generating both CD4(+) and CD8(+) T cell responses. More importantly, 16 of 17 melanoma patients who developed Ab against NY-ESO-1 were found to be HLA-DP4-positive. CD4(+) T cells specific for the NY-ESO-1 epitopes were generated from 5 of 6 melanoma patients with NY-ESO-1 Ab. In contrast, no specific DP4-restricted T cells were generated from two patients without detectable NY-ESO-1 Ab. These results suggested that NY-ESO-1-specific DP4-restricted CD4(+) T cells were closely associated with NY-ESO-1 Ab observed in melanoma patients and might play an important role in providing help for activating B cells for NY-ESO-1-specific Ab production.

The regulatory action of the modified Yu Ping Feng Tang on cellular immunity in mice under amputation-induced stress

To approach the action of modified Yu Ping Feng Tang ([symbol: see text] Jade-Screen Decoction) on cellular immunity, an experiment was conducted in mice under amputation-induced stress. On the 3rd day after amputation, acute atrophy was found in the thymus, the reactivities of T- and B-lymphocytes to Con-A and LPS were decreased, the IL-2 content and its activity reduced and the activity of NK cells lowered. The high, moderate and low concentrations of the modified Yu Ping Feng (YPF) Decoction all have antagonistic action on the above manifestations of immune inhibition.

Suppression of ganglioside GD3 expression in a rat F-11 tumor cell line reduces tumor growth, angiogenesis, and vascular endothelial growth factor production

Ganglioside GD3 is overexpressed in many types of tumors and may be associated with tumor progression and the development of metastatic potential. In our previous study (G. Zeng et al., Biochemistry, 38: 8762-8769, 1999), we established a subclone of the rat dorsal root ganglion-derived F-11 cells in which the expression of ganglioside GD3 was inhibited by stable transfection of the antisense vector against CMP-NeuAc: GM3 alpha2-8 sialyltransferase (GD3-synthase) gene. This cell line exhibits markedly reduced rate of tumor growth in vivo. Here, we further characterized the antisense-transfected cell line, and the results showed that these cells formed small, minimally vascularized tumors exhibiting extensive necrosis. In vivo Matrigel assay revealed reduced vascularization and low hemoglobin content in the antisense xenografts. Significantly fewer new vessels were found on the antisense xenografts and the skin around them than those on/around the xenografts formed by the sense-transfected and untransfected F-11 cells. The hemoglobin content of the antisense xenografts was much lower than that of the xenografts formed by the control cells. The reduced angiogenesis in the antisense xenografts was correlated with a decrease in vascular endothelial growth factor (VEGF) production. The expression of VEGF was suppressed in the antisense xenografts and the conditioned culture media of the antisense-transfected F-11 cells as determined by Western blotting analysis. This was further confirmed by immunohistochemistry of the tumors using antibodies against VEGF and platelet/endothelial cell adhesion molecule (PECAM-1). Therefore, our results demonstrate that reduced tumor growth in nude mice by suppression of GD3-synthase expression in F-11 cells results from minimal angiogenesis of the tumors through down-regulation of the VEGF expression, which indicates an important role for GD3 in tumor angiogenesis.

Reduced cell migration, tumor growth and experimental metastasis of rat F-11 cells whose expression of GD3-synthase is suppressed

We previously established a rat F-11 cell line whose expression of ganglioside GD3 was inhibited by stable transfection of the anti-sense vector against the GD3-synthase gene, showing that specific inhibition of GD3-synthase expression in tumor cells greatly reduced their growth rate in nude mice. Here, we report that down-regulation of GD3-synthase expression in anti-sense-transfected F-11 cells correlates with reduced cell migration and invasion in vitro and tumor growth and metastasis in vivo. When cultures were denuded of cells in a 1-mm-wide strip, the anti-sense-transfected F-11 cells migrated very slowly into the denuded area. Differences in migration between anti-sense-transfected cells and control parental cells were easily apparent. In vitro invasion assay of F-11 cells revealed a 3-fold decrease in invasion ability from the GD3-synthase-suppressed cells; colony formation in soft agar was not affected. Injection (i.v.) of control sense-transfected and untransfected F-11 cells resulted in multiple, large metastatic nodules in each of the 12 mice, whereas i.v. injection of anti-sense-transfected F-11 cells formed a single, small metastatic nodule in only 2 of the 8 nude mice. In addition, even if metastasis occurred, the anti-sense-induced metastatic nodules were much smaller than the metastatic nodules formed by control F-11 cells. These results demonstrate that suppression of GD3-synthase expression, which results primarily in a marked decrease in the concentration of ganglioside GD3, greatly reduces cell spreading, invasion and both the incidence and growth rate of experimental metastasis of F-11 cells.

[Usefulness of CT scan in secretory otitis media in patient with nasopharyngeal carcinoma]

OBJECTIVE

To explore the usefulness of CT scan in nasopharyngeal carcinoma (NPC) with secretory otitis media (SOM).

METHOD

CT of the nasopharynx and mastoid in 127 cases with NPC pro- and post-irradiation were analyzed.

RESULT

Total incidence rate of SOM was 59% before irradiation. The incidence corresponded to T stage and tumor location of NPC. In the patients without SOM before irradiation, 70 percent of the ears developed SOM, and the peak stage of the formation of SOM was in three to six month after irradiation.

CONCLUSION

CT scan for the patient with NPC is useful for the diagnosis and prognosis of SOM induced by NPC.

[Study of CFTR gene mutation in Chinese CUAVD patients]

OBJECTIVE

To analyze the frequency and hot spots of cystic fibrosis transmembrane conductance regulator(CFTR) gene in Chinese congenital unilateral absence of the vas deferens (CUAVD) patients.

METHODS

The mutation of CFTR exons 2, 3, 4, 5, 6a, 8, 10, 11, 12, 13, 15A, 17b, 19A, 20, 21, and 23 were detected. PCR-single strand conformation polymorphism(SSCP) and direct sequencing were performed on 15 cases of Chinese CUAVD.

RESULTS

One case exhibited an abnormal shift SSCP band in exon 17b of CFTR gene and subsequent DNA sequencing showed C to A transversion at position 3295 that led to a predicted change of Leusine(codon 1055, CTT) to Isoleucine(codon ATT).

CONCLUSION

CFTR mutation could be detected in Chinese CUAVD patients. The missense mutation, Leu1055Ile, was identified as a novel CFTR mutation. It is necessary that Chinese CUAVD patients and their wives should be screened for CFTR gene prior to intracytoplasmic sperm injection.

Identification of CD4+ T cell epitopes from NY-ESO-1 presented by HLA-DR molecules

In previous studies, the shared cancer-testis Ag, NY-ESO-1, was demonstrated to be recognized by both Abs and CD8+ T cells. Gene expression of NY-ESO-1 was detected in many tumor types, including melanoma, breast, and lung cancers, but was not found in normal tissues, with the exception of testis. In this study, we describe the identification of MHC class II-restricted T cell epitopes from NY-ESO-1. Candidate CD4+ T cell peptides were first identified using HLA-DR4 transgenic mice immunized with the NY-ESO-1 protein. NY-ESO-1-specific CD4+ T cells were then generated from PBMC of a patient with melanoma stimulated with the candidate peptides in vitro. These CD4+ T cells recognized NY-ESO-1 peptides or protein pulsed on HLA-DR4+ EBV B cells, and also recognized tumor cells expressing HLA-DR4 and NY-ESO-1. A 10-mer peptide (VLLKEFTVSG) was recognized by CD4+ T cells. These studies provide new opportunities for developing more effective vaccine strategies by using tumor-specific CD4+ T cells. This approach may be applicable to the identification of CD4+ T cell epitopes from many known tumor Ags recognized by CD8+ T cells.

Effect of 32/67 kDa laminin-binding protein antibody on mouse embryo implantation

Mouse embryo implantation depends on the complex interaction between the embryo trophoblast cells and the uterine environment, which deposits an extracellular matrix with abundant amounts of laminin. Intrauterine injection and blastocyst or ectoplacental cone culture models were used to study the effect of 32/67 kDa laminin-binding protein antibody on mouse embryo implantation in vivo and in vitro. Intrauterine injection of 32/67 kDa laminin-binding protein antibody (0.4 mg in 1 ml Ham's F-10 medium, 5 microl per mouse) into the left uterine horns of mice (n = 22) on day 3 of pregnancy inhibited embryo implantation significantly (P < 0.001) compared with the contralateral horns that had been injected with normal rabbit IgG. A continuous section study on day 5 after injection showed that the embryos in the control uteri implanted normally and developed healthily, but there were no embryos or the remaining embryos had disintegrated in the uteri injected with 32/67 kDa laminin-binding protein antibody. Blastocysts or ectoplacental cones were cultured in media containing 32/67 kDa laminin-binding protein antibody (0.2 mg ml(-1)) on laminin-coated dishes with normal rabbit IgG at the same concentration as in the controls. The 32/67 kDa laminin-binding protein had no effect on blastocyst or ectoplacental cone attachment, but prohibited the blastocyst or ectoplacental cone outgrowth and primary or secondary trophoblast giant cell migration. These results indicate that 32/67 kDa laminin-binding protein antibody blocked mouse embryo implantation by preventing embryo trophoblast cell invasion and migration through the uterine decidual basement membrane-like extracellular matrix which has a high laminin content.

Effect of 32/67 kDa laminin-binding protein antibody on mouse embryo implantation

Mouse embryo implantation depends on the complex interaction between the embryo trophoblast cells and the uterine environment, which deposits an extracellular matrix with abundant amounts of laminin. Intrauterine injection and blastocyst or ectoplacental cone culture models were used to study the effect of 32/67 kDa laminin-binding protein antibody on mouse embryo implantation in vivo and in vitro. Intrauterine injection of 32/67 kDa laminin-binding protein antibody (0.4 mg in 1 ml Ham's F-10 medium, 5 microl per mouse) into the left uterine horns of mice (n = 22) on day 3 of pregnancy inhibited embryo implantation significantly (P < 0.001) compared with the contralateral horns that had been injected with normal rabbit IgG. A continuous section study on day 5 after injection showed that the embryos in the control uteri implanted normally and developed healthily, but there were no embryos or the remaining embryos had disintegrated in the uteri injected with 32/67 kDa laminin-binding protein antibody. Blastocysts or ectoplacental cones were cultured in media containing 32/67 kDa laminin-binding protein antibody (0.2 mg ml(-1)) on laminin-coated dishes with normal rabbit IgG at the same concentration as in the controls. The 32/67 kDa laminin-binding protein had no effect on blastocyst or ectoplacental cone attachment, but prohibited the blastocyst or ectoplacental cone outgrowth and primary or secondary trophoblast giant cell migration. These results indicate that 32/67 kDa laminin-binding protein antibody blocked mouse embryo implantation by preventing embryo trophoblast cell invasion and migration through the uterine decidual basement membrane-like extracellular matrix which has a high laminin content.

Combination gene therapy: synergistic inhibition of human immunodeficiency virus Tat and Rev functions by a single RNA molecule

Current drug combinations can achieve long-term suppression of HIV replication in infected individuals. Unfortunately, complicated dosing schedules and high toxicity make long-term compliance with drug regimens difficult for most patients. Gene therapy may provide a permanent solution for HIV disease by generating cells genetically resistant to virus replication. As with the highly active antiretroviral therapies, genetic drugs must have strong antiviral potency and the ability to prevent the emergence of escape mutants. We have constructed antiviral genes containing unique combinations of Tat- and Rev-binding decoys. The new antiviral molecules are chimeric TAR-RRE RNAs that are expressed only in HIV infected cells in a Tat-regulated manner. One RNA molecule competes for both Tat and Rev binding, and thus blocks the activation and the expression of all viral genes. The two functional Tat- and Rev-binding domains exhibit the highest synergy at the lowest concentration. Conservative quantitative estimates of this synergistic effect were I = 0.24 at 50% inhibition, in terms of the Berenbaum "interaction index," indicating that the combined construct was approximately fourfold more potent than would be predicted on the basis of additive effects. The possibility of HIV escape from this inhibition is unlikely, because it requires simultaneous mutation of TAR and RRE in a manner in which both Tat and Rev preserve their respective functions. TAR-RRE combination decoys represent the first example of mathematically proven synergistic antiviral activity between two domains of the same molecule.

Roles for insulin receptor, PI3-kinase, and Akt in insulin-signaling pathways related to production of nitric oxide in human vascular endothelial cells

BACKGROUND

Previously, we demonstrated that insulin stimulates production of nitric oxide (NO) in endothelial cells. However, specific insulin-signaling pathways mediating production of NO have not been elucidated.

METHODS AND RESULTS

We developed methods for transfection of human umbilical vein endothelial cells (HUVECs) and direct measurement of NO to begin defining insulin-signaling pathways related to NO production. HUVECs were cotransfected with enhanced Green Fluorescent Protein (eGFP) and another gene of interest. Transfection efficiencies >95% were obtained by selecting cells expressing eGFP. Overexpression of insulin receptors in HUVECs resulted in an approximately 3-fold increase in production of NO in response to insulin. In contrast, HUVECs overexpressing a tyrosine kinase-deficient mutant insulin receptor had a dose-response curve similar to that of control cells. Overexpression of inhibitory mutants of either phosphatidylinositol 3-kinase (PI3K) or Akt resulted in nearly complete inhibition of insulin-stimulated production of NO. Overexpression of an inhibitory mutant of Ras had a much smaller effect.

CONCLUSIONS

Receptor kinase activity is necessary to mediate production of NO through the insulin receptor. Both PI3K and Akt contribute importantly to this process, whereas the contribution of Ras is small.

Characterization of a 12-kilodalton rhodanese encoded by glpE of Escherichia coli and its interaction with thioredoxin

Rhodaneses catalyze the transfer of the sulfane sulfur from thiosulfate or thiosulfonates to thiophilic acceptors such as cyanide and dithiols. In this work, we define for the first time the gene, and hence the amino acid sequence, of a 12-kDa rhodanese from Escherichia coli. Well-characterized rhodaneses are comprised of two structurally similar ca. 15-kDa domains. Hence, it is thought that duplication of an ancestral rhodanese gene gave rise to the genes that encode the two-domain rhodaneses. The glpE gene, a member of the sn-glycerol 3-phosphate (glp) regulon of E. coli, encodes the 12-kDa rhodanese. As for other characterized rhodaneses, kinetic analysis revealed that catalysis by purified GlpE occurs by way of an enzyme-sulfur intermediate utilizing a double-displacement mechanism requiring an active-site cysteine. The K(m)s for SSO(3)(2-) and CN(-) were 78 and 17 mM, respectively. The apparent molecular mass of GlpE under nondenaturing conditions was 22.5 kDa, indicating that GlpE functions as a dimer. GlpE exhibited a k(cat) of 230 s(-1). Thioredoxin 1 from E. coli, a small multifunctional dithiol protein, served as a sulfur acceptor substrate for GlpE with an apparent K(m) of 34 microM when thiosulfate was near its K(m), suggesting that thioredoxin 1 or related dithiol proteins could be physiological substrates for sulfurtransferases. The overall degree of amino acid sequence identity between GlpE and the active-site domain of mammalian rhodaneses is limited ( approximately 17%). This work is significant because it begins to reveal the variation in amino acid sequences present in the sulfurtransferases. GlpE is the first among the 41 proteins in COG0607 (rhodanese-related sulfurtransferases) of the database Clusters of Orthologous Groups of proteins (http://www.ncbi.nlm.nih.gov/COG/) for which sulfurtransferase activity has been confirmed.

[Study on regulatory effect of composite taixian tablet on immune function of red blood cell in patients with oral lichen planus]

OBJECTIVE

To explore the regulatory effect of Composite Taixian tablet (CTXT) on red blood cell (RBC) immune function in patients with oral lichen planus (OLP) for the sake of providing the basis of clinical medication.

METHODS

Sixty patients with OLP were assigned randomly into three groups and were treated by CTXT, Tripterygium hypoglaucum tablet and polyactin-A tablet respectively. And the changes of RBC-C3b receptor and immune circulating rosette complex on the surface of erythrocytes (RBC-ICR) were measured by saccharomycetic assay.

RESULTS

Effect of CTXT was superior to that of Tripterygium hypoglaucum and polyactin-A tablets.

CONCLUSION

CTXT is a relatively effective remedy with less side effect, it is worthy to be studied further.

Down-regulation of GD3 ganglioside and its O-acetylated derivative by stable transfection with antisense vector against GD3-synthase gene expression in hamster melanoma cells: effects on cellular growth, melanogenesis, and dendricity

The expression of gangliosides in hamster melanoma cells is closely related to cellular growth and degree of differentiation, with slow-growing, highly differentiated melanotic melanoma cells expressing GM3 and fast-growing, undifferentiated amelanotic Ab melanoma cells having a preponderance of GD3 and O-acetyl-GD3. We recently showed that down-regulation of O-acetyl-GD3 expression in hamster melanoma cells by introducing the influenza C virus O-acetylesterase cDNA into the cells resulted in induction of dendricity, with a concomitant increased expression of GD3. To examine the effect of the increased GD3 expression in the plasma membrane on the dendricity of the AbC-1 cells, we first established the cDNA coding for hamster GD3-synthase. We then targeted the sialyltransferase gene expression by the antisense knockdown experiment, and the results showed that inhibition of the expression of gangliosides GD3 and O-acetyl-GD3 induced dendricity in the hamster melanoma AbC-1 cell line. These GD3- and O-acetyl-GD3-depleted cells also demonstrated a decreased rate of cell growth, but their melanogenic potential was not affected. These results rule out the possibility that GD3 may serve as an active molecule for dendrite outgrowth in this cell line and suggest that the enhanced expression of O-acetyl-GD3 ganglioside may stimulate cellular growth and suppress certain differentiated phenotypes such as dendrite formation, but not melanogenesis, in our system.

Lactose (mal)digestion evaluated by the 13C-lactose digestion test

BACKGROUND

The prevalence of genetically determined lactase nonpersistence is based on the results of the lactose H2 breath test. This test, however, is an indirect test, which might lead to misinterpretation.

DESIGN

We determined lactase activity in healthy Chinese and Dutch students using a novel 13C-lactose digestion test. The cut-off value of this test was established in a Chinese population with a homogenous genetic background of lactase nonpersistence and was compared with the results obtained in a Caucasian population. Twenty-five grams of a 13C-lactose solution was consumed by 12 known H2-positive and 5 H2-negative Chinese students and 48 Dutch students and, subsequently, 13C-glucose concentration in plasma and H2 excretion in breath were measured.

RESULTS

A similar 13C-glucose response curve was found in all Chinese students. The mean response curve in the Dutch students was more pronounced (P < 0.01). The 1 h (peak) plasma 13C-glucose concentration was the best discriminator between lactose digesting and maldigesting subjects. The cut-off level of 2 mmol L-1 13C-glucose in plasma was defined in the H2-positive Chinese students group. Based on the 13C-glucose response the prevalence of lactose maldigestion in the Dutch subjects was 25%; based on the lactose H2 breath test 17%.

CONCLUSIONS

Using the 13C-lactose digestion test the results demonstrate a higher prevalence of lactose maldigestion in a Caucasian population than indicated by the results of the H2 breath test. A moderate increase in the plasma 13C-glucose concentration after consumption of 13C-lactose in the young adult Chinese subjects indicates a residual lactase activity in that age group, even when a positive H2 breath test result is obtained. These results indicate that the 13C-glucose concentration in plasma more accurately reflects the small intestinal lactose digestion capacity than the lactose H2 breath test.

Energy gain of injected electrons subjected to an intense laser field and its magnetic field induced in plasma

Cyclotron-resonance energy gain of injected electrons subjected to an intense circularly polarized laser field and the magnetic field induced in a low-density plasma is investigated theoretically. By considering the inverse Faraday effect (IFE), where a circularly polarized finite area laser beam induces an axial magnetic field in a plasma, it is found that very interesting energy gains can be obtained by Doppler-shifted cyclotron resonance in this field for the appropriate injection velocity. This same IFE field also acts to confine these electrons radially and, on exiting the plasma adiabatically, it is in this way that the transverse electron energy is converted to axial energy. Two limits to the energy gain are discussed: (i) cyclotron radius of the energetic electrons becoming comparable to the beam, and (ii) axial dephasing.

[Changes of simple epithelial cytokeratin during oral carcinogenesis]

OBJECTIVE

To investigate whether the simple epithelial cytokeratin CK18 and CK19 can be used as a marker of oral precancerous lesions.

METHODS

Formalin-fixed, paraffin-embedded tissue sections of normal oral mucosa, epithelial hyperplasia, mild epithelial dysplasia, moderate epithelial dysplasia, severe epithelial dysplasia and oral squamous cell carcinomas were stained with a CK18-specific antibody and CK19-specific antibody respectively by LSAB immunohistochemical method. The stained sections were observed under light microscopy. The results were described and analyzed with Rank Sum Test.

RESULTS

CK18 was not detected in normal and abnormal oral tissue sections. But in normal nonkeratinized mucosa, CK19 was detected in the basal cell layer dispersively. In epithelial dysplasia, CK19 was detected in the suprabasal cell layer and the number of CK19-positive cell layers was correlated with the dysplasia degree of epithelia. Furthermore, CK19 was detected in oral squamous cell carcinoma, especially in the poor-differentiated cancer cells.

CONCLUSION

CK19 expression in suprabasal cell layer of oral mucosa can be used as a candidate marker for diagnosis of oral precancerous lesions and determination of the differentiation level of oral squamous cell carcinoma.