[Expression of cytokines in labial gland of Sjögren's syndrome]

OBJECTIVE

To explore the role of cytokines in the process of inflammation and destruction of minor salivary gland in Sjögren's Syndrome. (SS) METHODS: Using in situ non-isotope double hybridization method, we detected the mRNA of the following cytokines: TNF alpha, IL-1 beta, IL-6, PDGF alpha and PDGF beta in 24 labial gland biopsied sections.

RESULTS

No cytokine could be detected in the normal labial glands sections. The positivity of all cytokine expression was higher in the pSS and sSS patients than that in the control. The intensity of TNF alpha expression was 3-4 fold increase in pSS compared with sSS. The different cytokines were expressed with the different grade of lymphocytic focus. The site of different cytokines was also expressed differently. The coexpression of mRNA of TNF alpha and IL-1 beta or TNF alpha and IL-6 was only seen in the inflammatory mononuclear cells but not others. The expression of TNF alpha in aciniar cells could occur earlier than the infiltration of lymphocytes in the interstitial region. It was found that the IL-6 positive group had higher positivity of serum ANA compared with the IL-6 negative group according to Ridit statistical analysis (P < 0.05). The serum anti-SSA and anti-SSB antibody had an increase tendency in the IL-6 positive group.

CONCLUSION

We hypothesize that the development of SS may be secondary to some trigger agents, which activated the aciniar cells in exocrine gland of predisposed individuals. The activated acini cells secreted TNF alpha, then TNF alpha induced other cytokine expression, followed by the lymphocytes infiltration, which led to autoimmne reaction and the destruction of the exocrine gland.

Gene therapy for malignant gliomas using replication incompetent retroviral and adenoviral vectors encoding the cytochrome P450 2B1 gene together with cyclophosphamide

Cyclophosphamide is an inactive prodrug which is converted by hepatic cytochrome P450 2B1 to cytotoxic metabolites which produce interstrand DNA cross-linking in a cell cycle-independent fashion. The limited ability of these metabolites to cross the blood-brain barrier contributes to the poor activity of cyclophosphamide against brain tumors. In this study we demonstrate that replication deficient retroviral and adenoviral vector-mediated gene transfer of cytochrome P450 2B1 into 9L glioma cells significantly increases the sensitivity of these tumor cells to cyclophosphamide in vitro, and prolongs the survival of animals bearing intracerebral 9L tumors treated with cyclophosphamide in vivo. Attempts to improve the effectiveness of retrovirally mediated transduction of the P450 2B1 gene by increasing the concentration of cyclophosphamide delivered to the tumors using intracarotid and intratumoral injections did not prolong animal survival, although survival was increased when a second treatment with P450-expressing retroviral vectors and cyclophosphamide was administered. These results suggest that in situ transduction of tumor cells with the P450 2B1 gene using retroviral and adenoviral vectors increases their sensitivity to cyclophosphamide and may have a potential role in the therapy of malignant gliomas.

Antitumor effects of a refined polysaccharide peptide fraction isolated from Coriolus versicolor: in vitro and in vivo studies

RPSP, a refined polysaccharide peptide fraction isolated by fast performance liquid chromatography (FPLC) from the crude powder of total peptide-bound polysaccharides of cultivated Coriolus versicolor Cov-1 dose-dependently inhibited the proliferation of a human hepatoma cell line (HEPG2). The effective dose causing 50% inhibition following 3-day exposure to RPSP was 243 +/- 36 micrograms/ml for HEPG2. However, little or no inhibitory effects were detected in normal human foetal hepatocytes. On the other hand, in the pretreatment group, in which RPSP was administered i.p. for two weeks before sarcoma 180 inoculation in nude mice, the incidence of tumor growth was less (2 out of 5 mice) than that of the control group (all 5 mice). The tumor size of the control group was about 3-5 times bigger than that of the pretreatment group. In tumor-bearing nude mice, 5 days after sarcoma 180 inoculation, i.v. administration of RPSP significantly suppressed the growth of tumor mass. The inhibition rate was 93.6% on day 13. Furthermore, administration of RPSP did not cause any pathological lesions in vital organs of rabbits such as heart, liver, spleen, lung and kidney. In conclusion, these results indicate that RPSP acts by directly suppressing tumor cell growth in vitro and the prevention of in vivo growth of tumor mass is probably mediated also via its immunomodulating effects.

Viral vector transduction of the human deoxycytidine kinase cDNA sensitizes glioma cells to the cytotoxic effects of cytosine arabinoside in vitro and in vivo

Cytosine arabinoside (ara-C) is a cytidine analog that incorporates into replicating DNA and induces lethal DNA strand breaks. Although ara-C is a potent antitumor agent for hematologic malignancies, it has only minimal activity against most solid tumors. The rate-limiting step in intracellular ara-C activation is phosphorylation of the prodrug by deoxycytidine kinase (dCK). The present results demonstrate that both retroviral and adenoviral vector-mediated transduction of the dCK cDNA results in marked sensitization of glioma cells lines to the cytotoxic effects of ara-C in vitro. We also demonstrate that ara-C treatment of established intradermal and intracerebral gliomas transduced with dCK results in significant antitumor effects in vivo. These data suggest that viral vector transduction of the dCK gene followed by treatment with ara-C represents a new chemosensitization strategy for cancer gene therapy.

In vivo replication-deficient adenovirus vector-mediated transduction of the cytosine deaminase gene sensitizes glioma cells to 5-fluorocytosine

Viral vector-mediated transfer of chemosensitization genes represents a promising new approach to the treatment of cancer. Previous reports have demonstrated that transfection of the bacterial cytosine deaminase (cd) gene into mammalian cells can sensitize them to the otherwise nontoxic nucleoside, 5-fluorocytosine (5-FC). We now report that a replication-deficient adenovirus vector that transduces the cd gene (Ad.CMV-cd) highly sensitizes 9L gliosarcoma cells to 5-FC, and that gene transduction is associated with a potent bystander effect that is not dependent on direct cell-to-cell contact. Stereotactic injection of Ad.CMV-cd into established rat gliomas, followed by systemic administration of 5-FC in vivo, results in prolongation of survival.

[Preliminary diagnostic criteria for primary Sjogren's syndrome in China]

Primary Sjogren's syndrome (pSS) is a common autoimmune connective tissue disease in China yet without a universally accepted diagnostic criteria. In this study a new criteria was proposed and compared with other six sets of criteria. Fifty-five items in 112 pSS and 185 controls were evaluated. Results show the criteria we proposed contained one major and nine minor items. For the purpose of identifying patients in clinical studies, a major with at least three of the nine minor items or at least five of the minor items should be presented. The major item is anti-SSA/SSB(+) and the minors are, (1) dry eyes or dry mouth (> 3 months, persistently), (2) swollen salivary glands (recurrently or persistently), (3) rampant dental caries, (4) Schirmer test (< 5 mm in 5 min.) or corneal staining(+), (5) unstimulated salivary flow (< 0.03 ml/min) or abornal parotid sialography, (6) minor salivary gland biopsy (> or = 1 focus), (7) renal tubular acidosis, (8) hypergammaglobuminemia (gamma globulin > or = 30%) or hypergammaglobuminemic purpura, (9) RF > 1 : 20 or ANA > 1 : 20. Other connective tissure diseases, pre-existing lymphoma, AIDS, sarcoidosis, graft vs host disease must be excluded. The criteria we proposed had a high specificity of 98.2% and sensitivity of 94.1%.

[CuZn-SOD determination of sera in patients with rheumatic diseases]

Superoxide anion (O2.-) plays an important part in reactive oxygen species (ROS). In order to explore its effect on the pathogenesis of rheumatic diseases, authors had determined CuZn-SOD contents of sera in 132 subjects involving the patients of rheumatic diseases (SLE, RA, etc), non-rheumatic diseases and normal controls by using enzyme linked immunosorbent assay (ELISA). The results showed the followings: CuZn-SOD contents of 27 normal subjects: 98.80 +/- 20.74 ng/ml (x +/- s); that of 27 non-rheumatic diseases cases: 72.24 +/- 16.60 ng/ml (x +/- s); of 22 SLE cases: 56.56 +/- 19.27 ng/ml (x +/- s); of 27 RA cases: 61.56 +/- 20.53 ng/ml (x +/- s); of 29 other rheumatic diseases cases: 68.97 +/- 17.79 ng/ml (x +/- s). Statistical test was made: both CuZn-SOD contents of rheumatic disease and non-rheumatic disease were lower than that of normal subjects with more significant difference (P < 0.001); compared with that of non-rheumatic diseases patients, SLE cases had significant difference (P < 0.01); RA cases had significant difference (P < 0.05); other cases of rheumatic diseases had no statistical differrence (P > 0.05). Above results suggest that superoxide anion is a non-specific inflammatory mediator which contributes to disorders with inflammatory damages (rheumatic or non-rheumatic diseases), where CuZn-SOD content tested was obviously lower than normal subjects; among the rheumatic disease patients, CuZn-SOD contents of the sera of SLE patients were the lowest because of its more autoimmune antibody, more severe inflammatory and immunological reaction. This work laid the theoretical and experimental foundation for the clinical application of exogenous CuZn-SOD in the treatment of rheumatic diseases. Combined use of CuZn-SOD scavengers may get better result because of the complexibility of ROS inflammatory mechanism.

[Ribozyme targeted the point-mutation of activated oncogene inhibits its expression in vivo]

We demonstrated previously that the hammerhead ribozyme designed by us against the activated oncogene T24-ras cleaved the target mRNA specifically and efficiently in vitro. To study its properties in vivo, we cloned the DNA fragment encoding the ribozyme into the eukaryotic expression vector pSMG and transfected it into the T24-ras gene transformed NIH3T3 cell lines. The intracellular cleavage of T24-ras mRNA was evaluated on either the cytological level or the molecular level. The malignant cells expressing ribozyme were partially reversed in morphology as evidenced by slower growth speed, partial recovery of contact-inhibition, reduced frequency of colony forming in soft agar and close-to-normal behaviour in agglutination teat. The primer extension experiment verified that the ribozyme had efficiently cleaved the transcripts of T24-ras gene at the target site in vivo.

[Expression of p53 in human esophageal carcinoma and pre-malignant lesions in the esophagus]

The levels of p53 protein were detected by immunocytochemistry in 197 endoscopic biopsy specimens of esophagus. Nuclear p53 protein was present in 2.9% of normal mucosa, 6.7% of inflammatory mucosa, 38.8% of mild dysplasia, 52.0% of moderate or severe dysplasia, 61.1% of carcinomas in situ, 62.5% of invasive carcinomas. Moreover, we examined 14 cases of esophageal carcinoma with extensive dysplasia near the carcinoma and found high levels of p53 protein in both dysplasias and carcinomas in 8 cases. In one case, carcinoma presented high level of p53 protein while the adjacent dysplasia did not. In another case, the result was just the opposite. Negativity for p53 immunostaining was found in 4 cases. These data indicated that p53 protein accumulation occurred before tumor invasion in the multistage esophageal carcinogenesis. The timing and the frequency of p53 protein accumulation made p53 gene an attractive marker for the early diagnosis an the evaluation of chemopreventive agents.

Breast cancer selective gene expression and therapy mediated by recombinant adenoviruses containing the DF3/MUC1 promoter

The high molecular weight mucin-like glycoprotein, DF3 (MUC1), is overexpressed in the majority of human breast cancers. Here we demonstrate that replication defective recombinant adenoviral vectors, containing the DF3 promoter (bp -725 to +31), can be used to express beta-galactosidase (Ad.DF3-betagal) and the herpes simplex virus thymidine kinase (HSV-tk) gene (Ad.Df3-tk) in DF3 positive breast carcinoma cell lines. In vivo experiments using breast tumor implants in nude mice injected with Ad.DF3-betagal demonstrated that expression of the beta-galactosidase gene is limited to DF3-positive breast cancer xenografts. Moreover, in an intraperitoneal breast cancer metastases model, we show that i.p. injection of Ad.DF3-tk followed by GCV treatment results in inhibition of tumor growth. These results demonstrate that utilization of the DF3 promoter in an adenoviral vector can confer selective expression of heterologous genes in breast cancer cells in vitro and in vivo.

Ins(1,4,5)P3 activates Drosophila cation channel Trpl in recombinant baculovirus-infected Sf9 insect cells

The trp-like (trpl) gene product (Trpl) is thought to form a nonselective cation channel important for signal transduction in Drosophila photoreceptor cells. This channel may be the insect homologue of mammalian channels involved in Ca2+ signal transduction. To determine the mechanism of receptor-mediated activation of Trpl, whole cell membrane currents were examined in Sf9 insect cells after infection with recombinant baculovirus. Stimulation by bradykinin increased whole cell Trpl currents three- to fivefold. Similar activation of Trpl was observed by inclusion of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in the pipette solution during whole cell recordings. These currents were 1) not seen in noninfected cells or in cells expressing only the B2 receptor, 2) mimicked by D-myo-inositol 2,4,5-trisphosphate, and 3-deoxy-3-fluoro-D-myo-inositol 1,4,5-trisphosphate, 3) not seen with D-myo-inositol 1,4-bisphosphate or D-myo-inositol 1,3,4,5-tetrakisphosphate, and 4) blocked by heparin, but not by de-N-sulfated heparin. In contrast, Trpl currents were unaffected by thapsigargin. These results demonstrate that the Trpl cation channel is activated by Ins(1,4,5)P3 in a heparin-sensitive fashion. Regulation of channel activity by Ins(1,4,5)P3 may occur by a number of mechanisms, including direct binding of Ins(1,4,5)P3 to the Trpl channel or direct physical interaction between the Ins(1,4,5)P3 receptor/Ca(2+)-release channel of the endoplasmic reticulum and the Trpl protein.

Ultrastructural cytochemistry of human gastric cancer: electron microscopic observations of five organellae marker enzymes

The distribution of ALPase, ACPase, G6Pase TPPase and CCOase of gastric cancer and normal gastric epithelium were studied ultrastructurally. The results showed that normal gastric epithelium had no ALPase reaction. The reactions of ACPase, G6Pase, TPPase and CCOase were found in the corresponding organellae which were consistent with their functions. In tubular adenocarcinoma cells, their reactions were more apparent in the corresponding organellae. Some cells of tubular adenocarcinomas showed ALPase reaction. The mucinous adenocarcinoma cells had higher ACPase and TPPase reactions. In poorly differentiated adenocarcinoma cells, the five marker enzymes showed negative or faint reactions. The biological significance and mechanisms of distribution of the five marker enzymes were discussed.

[Effect of sex steroids on serum amyloid P-component (female protein) in rats]

Serum amyloid P-component (SAP) has been designated as a female protein in hamsters. But such a distinction is not made for rats. In order to investigate the effects of sex-steroids on the SAP level in rats, SAP was purified from Wistar rats by affinity chromatography of phosphorylcholine, followed by gel filtration. Anti-SAP was raised through the immunization of rabbits with the rat SAP and Freund's adjuvant. Sample sera were obtained from 180 young and old rats, after which rats were injected with estradiol (E2), testosterone (T) or dehydroepiandrosterone (DHEA). Sera were serially obtained from the tail vessels until the 8th day after injection. The SAP level was assayed by micro single radial immunodiffusion. As the rats aged, the SAP levels increased from 2.9 mg/dl at 11 weeks to 10.7mg/dl at 58 weeks. In 37-week-old rats, the SAP levels in females (6.3 +/- 1.8 mg/dl) were significantly (p < 0.001) higher than those in males (3.9 +/- 1.0 mg/dl). The SAP levels did not change after T administration, but were increased rapidly by E2 administration, especially in young male rats (increased from 2.6 +/- 0.2 mg/dl to 4.9 +/- 0.7 mg/dl). The SAP levels were decreased significantly (p < 0.05) by DHEA injection. Serum E2 levels in young (11 wk) male rats were very low before E2 injection, and rose steeply on the 2nd day. From these findings, the different SAP levels in mature female and male rats are attributed to E2.

[Interspecific protoplast fusion between Bacillus thuringensis Bt-3701 and Bacillus megaterium Bm-107]

The results of the interspecific protoplast fusion between B. thuringensis sub. kurstaki Bt-3701 which has pesticide ability, and B. megaterium var. phosphaticum Bm-107 which has decomposing phosphate activity, were reported. High frequency of protoplast formation and regeneration was obtained with 4h activated Bm-107 treated by 100 micrograms/ml lysozyme, and with 2h activated Bt-3701 treated by 3% glycin and mild temperature. Using 40% PEG and 5% nascent Ca2+ to treat the parential protoplast mixture for 3 min at 37 degrees C, 4 stable fusants were obtained. Biological tests show that they have both pesticide ability and decomposing phosphate activity, but which are weaker than that of parential strains.

Changes in lens connexin expression lead to increased gap junctional voltage dependence and conductance

The differentiation of mouse lens epithelial cells into fiber cells is a useful model for studying the changes of the electrical properties of gap junction (cell-to-cell) channels that are induced by an alteration in connexin expression patterns. In this model, cuboidal lens epithelial cells differentiate into elongated fiber cells, and the expression of connexin43 (Cx43) in the epithelial cells is replaced with the production of high levels of Cx50 and Cx46 in the fiber cells. We now report a new procedure to isolate mouse lens fiber cell pairs suitable for double whole cell patch-clamp analysis. Analysis was also performed for fiberlike cell pairs differentiated from epithelial cells in culture. Voltage dependence and unitary conductance of fiber cell gap junction channels were determined and compared with the corresponding values previously measured for the channels joining lens epithelial cells and for lens connexin channels formed in Xenopus oocyte pairs. Our results support a differentiation-induced shift toward stronger gap junctional voltage dependence and larger unitary conductances in the fiber cells. Our data further reflect a balanced functional contribution of Cx50 and Cx46 in the fiber cell-to-cell channels rather than a predominance of a single connexin.

Ocular lens gap junctions: protein expression, assembly, and structure-function analysis

Recent advances in understanding lens fiber gap junction formation are reviewed. These include studies of junctional protein expression in the embryonic lens, and of age related changes affecting gap junction structure and composition in the adult lens. An in vitro assembly system based on detergent solubilized pore complexes and endogenous lipids has been developed to provide information on the molecular interactions involved in gap junction formation and to provide material for structure analysis. Important information on the electrical properties of lens gap junction channels is obtained using electrophysiological techniques including planar lipid bilayer analysis and patch clamping.

An association study between essential hypertension and HLA-DRB1 alleles

It is well established that genetic and environmental factors are involved in the etiology of essential hypertension (EH). Previous studies have suggested that at least one of the HLA genes is responsible for the genetic susceptibility to EH. Our aim in the present study was to investigate this issue in China by the PCR-SSP HLA-DRB1 typing method. The results showed an increased frequency of HLA-DR2 and a decreased frequency of HLA-DR7 with EH patients compared with controls. We consider that HLA-DR2 may represent a marker for susceptibility to EH in the North Chinese population.

Insulin-like growth factor (IGF) I and retinoic acid induce the synthesis of IGF-binding protein 5 in rat osteoblastic cells

The insulin-like growth factor (IGF) regulatory system has a major impact on bone physiology. Among the modulators of IGFs, a family of structurally related proteins, the IGF-binding proteins (IGFBPs), have been shown to either potentiate or inhibit IGF actions on bone growth. However, the regulation of IGFBP expression in bone cells is not completely understood. In the present study, the expression of IGFBP-5 was analyzed in primary osteoblastic cells (Ob cells) isolated from 22-day-old fetal rat calvariae. Treatment of Ob cells with either IGF-I or all-trans-retinoic acid (RA) caused a time- and dose-dependent increase in IGFBP-5 messenger RNA (mRNA) levels, as determined by Northern blot analysis. Stimulation of IGFBP-5 mRNA was obtained at 100 nM IGF-I between 6 and 16 h (2- to 2.5-fold) and 100 nM RA between 16 and 24 h (3- to 4-fold). Concomitant treatment of Ob cells with IGF-I and RA revealed an additive effect and a 5- to 7-fold increase in IGFBP-5 mRNA levels after 16-24 h. The effect of IGF-I and RA and their combination on IGFBP-5 transcripts was similar in confluent and subconfluent cultures of Ob cells. IGF-I and RA did not change IGFBP-5 mRNA stability in Ob cells after transcription arrest with the RNA polymerase II inhibitor 5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole. IGF-I and RA at 100 nM elevated the levels of IGFBP-5 heterogenous nuclear RNA, measured by reverse transcription-polymerase chain reaction. The effect was similar to that observed on mRNA levels. IGFBP-5 from rat Ob cells appeared as a single band of 31 kilodaltons in both the conditioned medium and the extracellular matrix as determined by Western immunoblots. IGF-I and RA, both at 100 nM, increased IGFBP-5 by 2- to 3-fold after 24 h. In conclusion, IGF-I and RA modify the synthesis and secretion of IGFBP-5 in rat Ob cells through pathways that may involve increased transcription and elongation and/or altered processing of heterogenous nuclear RNA. Our data suggest that IGFBP-5 may play a role in the osteoblastic-differentiated function regulated by IGF-I and RA.

Prevalence of primary Sjögren's syndrome in China

OBJECTIVE

To determine the prevalence rate of primary Sjögren's syndrome (SS) in a community population of 2066 adults in a Beijing suburban village, and 100 inpatients, who were not necessarily admitted for rheumatic diseases.

METHODS

Questionnaire and serological studies of antinuclear antibodies, rheumatoid factor, and anti-SSA, anti-SSB antibodies were done. Possible positive subjects were given eye and oral examinations for objective evidence of xerostomia and keratoconjunctivitis sicca.

RESULTS

According to the Copenhagen criteria, the prevalence rate of primary Sjögren's syndrome in China was 0.77%, and it was 0.33% by modified San Diego criteria. In 100 inpatients, we found 4 cases of primary Sjögren's syndrome by Copenhagen criteria, and one case by modified San Diego criteria.

CONCLUSION

Primary Sjögren's syndrome is not a rare disease in China, but most cases are overlooked or misdiagnosed.

An upstream control region required for inducible transcription of the mouse H1(zero) histone gene during terminal differentiation

The replacement linker histone H1 (zero) is associated with terminal differentiation in many mammalian cell types, and its accumulation in chromatin may contribute to transcriptional repression occurring during terminal differentiation. H1 (zero) also accumulates in a variety of cell culture lines undergoing terminal differentiation. During in vitro mouse erythroleukemia cell differentiation, H1 (zero) gene expression is induced very rapidly, prior to the time when the cells actually commit to terminal differentiation. We have used a combination of transfection assays and in vitro DNA-protein interaction studies to identify nuclear protein binding sites in the H1 (zero) promoter that control expression and induction of the H1(zero) gene in mouse erythroleukemia cells. The results indicate that transcription of the H1 (zero) gene is controlled by three elements present in the upstream region of the promoter between positions -305 and -470. Site-directed mutagenesis of each of these elements showed that one of them controls inducibility of the gene in differentiating cells. The other two elements in the upstream control region affect primarily the level of transcription of the gene in undifferentiated and differentiating cells. These two elements share a DNA sequence motif consisting of a (dG)6 tract contained in an eight-base consensus, (A/C)GGGGGG(A/C). Additional copies of this motif are present elsewhere in the H1 (zero) promoter.

Rapid HLA-DRB1 generic typing by PCR-SSP method

We report a simple and rapid HLA-DRB1 generic typing method, PCR-SSP, which is practical and inexpensive. We use 9 sequence-specific primers and 2 group specific primers to define the HLA-DRB1 specificities DR1, DR2, DR3, DR4, DR5, DR6, DR7, DR8, DR9 and DR10. The HLA DR3, DR5, DR6 and DR8 can be amplified by the two primers of DR3568 and DRB1. The DR6 specificity can be identified by excluding the DR3, DR5 and DR8 when the DR3568 are positive. Any individuals can be typed with some exception: the three pairs of phenotype DR3/DR3 and DR3/DR6, DR5/DR5 and DR5/DR6, DR8/DR8 and DR8/DR6 cannot be discriminated from each other. We typed 106 unrelated healthy people from Beijing locations in two weeks. We think this typing method is suitable to replace the error-prone serologic HLA-DR tests in routine clinical practice, including the prospective typing of cadaveric organ donors.