Objective To investigate the difference of apparent diffusion coefficients (ADCs) changes in three major salivary glands after gustatory stimulation using two different stimuli. Methods Thirty healthy volunteers were examined with a 1.5 T MR unit. A diffusion-weighted MR imaging (MR DWI) sequence was performed once at rest and continuously repeated 13 times after gustatory stimulation using a commercially available lemon juice and vitamin C tablets in the same volunteer by using self-controlled method. The subsequence of two stimuli was random. In addition, the salivary flow rates at rest and after stimulation were measured. Characteristics and differences in ADCs curves of three salivary glands before and after stimulation between two stimuli were analyzed. Comparison of maximum ADCs, maximum ADCs increase rates (IRs) and times to maximum ADCs(Tmax) between two stimuli was performed by using independent-samples t test. Correlation analysis between rest salivary flow rates and rest ADCs, the maximum salivary flow rates and ADCs after stimulation, the maximum salivary flow IRs and ADC IRs after stimulation were performed by using Pearson correlation test. Results In lemon juice stimulation group, the mean ADCs mostly showed a steady increase to peak values during the first DW MRI scan after stimulation in all glands, followed by a gradually decrease fluctuating slightly around the baseline values. In vitamin C stimulation group, the mean ADCs were significantly increased in all glands during the first DW MRI scan after stimulation, followed by a gradual upward trend till peak values. In lemon juice stimulation group, the mean Tmax of submandibular and sublingual glands[(184±122)s, (345±232)s, respectively] were significantly earlier than those[(454 ± 301)s, (528 ± 297)s, respectively] in vitamin C stimulation group (t=-3.517 and-2.548 respectively, P<0.01 for all). The mean maximum ADCs of three glands in lemon juice stimulation group[(1.05 ± 0.12) × 10-3 mm2/s, (1.22 ± 0.10) × 10-3 mm2/s and (1.26 ± 0.21) × 10-3 mm2/s, respectively] were all lower than those in vitamin C stimulation group[(1.13±0.13) ×10-3 mm2/s, (1.32±0.25) × 10-3 mm2/s and (1.57 ± 0.36) × 10-3 mm2/s, respectively], and the differences in parotid and sublingual glands between two groups were significant(t=-2.894 and-3.681 respectively, P<0.01 for all). The mean maximum ADC IRs of three glands in lemon juice stimulation group[(11.35±4.07)%, (8.81±5.40)%, (34.08±21.66)%, respectively] were significantly lower than those[(17.80 ± 12.72)%, (18.16 ± 18.93)%, (67.49 ± 46.04)% , respectively] in vitamin C stimulation group (t=-2.252,-2.330 and-3.432 respectively, P<0.05 for all) . In two groups, the mean maximum ADC IRs of parotid and submandibular gland were all significantly lower than sublingual gland (t=-5.994 and-6.443 respectively, P<0.01 for all). No correlation was observed between ADCs and salivary flow rates, ADC IRs and salivary flow rate IRs in two groups (P>0.05). Conclusion MR DWI with transient stimulation using lemon juice is more stable for evaluating the physiologic changes of salivary glands in vivo.

BACKGROUNDTo investigate the expression of cancer-testis antigens(CTA) in human lung cancer.

METHODSReverse-transcription polymerase chain reaction (RT-PCR) was used to investigate the expression of the MAGE-1, -3, SSX-1, -2, -4, -5 and NY-ESO-1 genes in 35 lung cancer samples and corresponding non-tumorous lung tissues. Three samples selected randomly from each CTA PCR product were sequenced.

RESULTSIn 35 tumor samples, the MAGE-1, -3, SSX-1, -2, -4, -5 and NY-ESO-1 mRNA expression rates were 34.3%(12/35), 57.1%(20/35), 17.1%(6/35), 17.1%(6/35), 20.0%(7/35), 25.7%(9/35) and 37.1%(13/35), respectively. The positive rate was 74.3%(26/35) for at least one of these genes expression, and 65.7%(23/35) for two or more genes coexpression. No non-tumorous lung tissue was positive for these genes. The DNA sequence confirmed that the RT-PCR products were truly CTA cDNA.

CONCLUSIONSThe cancer-testis antigens are potential targets for antigen-special immunotherapy of lung cancer. The coexpression pattern of these antigens provides a theoretic foundation for developing a polyvalent lung cancer vaccine.

BACKGROUNDTo investigate whether autologous lung cancer tissues derived gp96-peptide complex/dendritic cell vaccine could induce peptide specific cytotoxic T lymphocyte (CTL) response in vitro.

METHODSA patient's tumor-derived antigens including gp96-peptide complexes and tumor cell lysate were co cultured with DCs derived from the same patient's bone marrow blood mononuclear cells. The various antigen/DC vaccines were used to stimulate peripheral lymphocytes. Interferon-γ (IFN-γ) level of activated lymphocytes was detected by ELISA method and the Cr51 release test was performed to evaluate the gp96-peptide specific CTL response in three kinds of target cells including the primary cultured tumor cells, PG cells and K562 cells.

RESULTSIFN-γ could be observed from the supernate collected in all antigen groups after the cognate T lymphocytes were stimulated by various vaccines. The concentration of IFN-γ induced by gp96-peptide complexes/DC vaccine was higher than that of other groups. In addition, the killing effect of the activated T lymphocytes on patient's primary tumor cells was higher than that on PG and K562 cells.

CONCLUSIONSAutologous tumor-derived gp96-peptide complexes can induce a peptide complex specific CTL response, and the CTL response is significantly intensified after DCs are pulsed.

BACKGROUNDTo clone and identify genes differentially expressed in human lung squamous cell carcinoma (LSCC).

METHODSA subtracted cDNA library of human LSCC was constructed by suppression subtracted hybridization (SSH) method. After screening, the subtracted library clones representing mRNAs that were truly differentially expressed in LSCC but not in its adjacent non cancerous tissues were selected to identify by RT-PCR and DNA sequencing were performed. Nucleic acid homology searches were performed using the BLAST program.

RESULTSBy this technique, 10 differentially expressed gene cDNA fragments of LSSC were obtained. Two were novel and eight were already known genes.

CONCLUSIONSSSH is a useful technique with high sensitivity for the detection of differential genes expression in LSCC and an effective method to clone novel genes.