Sexual isolation and cuticular hydrocarbons in Drosophila elegans

In Drosophila elegans, partial sexual isolation has developed between the brown and black morphs, which are distributed allopatrically. The present study aims to understand how they discriminate between potential mates. Mating experiments show that the females of the two morphs differ in sexual signal(s) and the males discriminate using these differences. Body colouration is not used as a sexual cue in this species. Between the females of the two morphs, a large difference was observed in the percentages of 7-pentacosene and 9-pentacosene on the cuticle. Genetical analysis using recombinant inbred lines supported the possibility that the concentration of these pentacosenes plays a role in mate discrimination of these two morphs. However, males did not respond to killed females at all, suggesting that cuticular hydrocarbons of females are not the only cue for the induction of male courtship behaviour. It may be that unknown signals or substances are essential to induce male courtship and pentacosenes modulate the attractiveness of females, positively in the black morph and negatively in the brown morph. Drosophila elegans F1 offspring had intermediate characteristics in mate discrimination and hydrocarbon composition between the parental brown and black morph strains. The number of loci responsible for the differences in the concentration of pentacosenes and the male and female components in the mate recognition between these two morphs is suggested to be more than one.

Somatic mutations of the PTEN/NMAC1 gene associated with frequent chromosomal loss detected using comparative genomic hybridization in endometrial cancer

OBJECTIVES

We analyzed the mutational status of the transforming growth factor-beta type II receptor (TGF beta RII), BAX, and PTEN/MMAC1 genes as well as microsatellite instability (MI) in 29 consecutive cases of endometrial carcinoma operated on at the Cancer Institute Hospital (Tokyo, Japan). To identify chromosomal loss associated with significant somatic mutations, we conducted comparative genomic hybridization (CGH) analysis.

METHODS

We conducted a direct sequence for mutational analysis of these genes. To examine copy number loss at the chromosomal regions bearing these genes, we used CGH analysis. CGH analysis may provides a genome-wide overview about tumor-associated genomic imbalances.

RESULTS

Among nine tumors that showed the MI+ phenotype, four (44%) demonstrated a significant mutation with a definite amino acid change in the PTEN/MMAC1 gene. CGH analysis demonstrated that all four tumors (100%) showed chromosomal copy number loss around the locus of this gene, whereas four (57%) of seven tumors with PTEN/MMAC1 mutations showed chromosomal loss or double mutations in MI- carcinomas. The role of TGF beta RII and BAX genes is limited as a target gene of MI+ phenotype in endometrial cancer, because several mutations of these genes were detected but a chromosomal loss was demonstrated by CGH in only one tumor in MI+ endometrial cancers with mutation.

CONCLUSIONS

This report reveals, by using CGH, that most MI+ endometrial cancers with PTEN/MMAC1 mutations as well as MI- tumors showed inactivation of both alleles of this gene, which strongly suggested the involvement of this gene in carcinogenesis.

Analysis of E6 variants of human papillomavirus type 33, 52 and 58 in Japanese women with cervical intraepithelial neoplasia/cervical cancer in relation to their oncogenic potential

The variation of the E6 region of human papillomavirus type 16 (HPV16) is associated with a high risk for cervical carcinogenesis. To see whether the same is the case with HPV33, 52 and 58, known to have high homology with HPV16, we analyzed the E6 sequence variation of these HPVs in 107 Japanese women with cervical intraepithelial neoplasia (CIN) or invasive cervical cancer (ICC): 20 HPV33-positive, 46 HPV52-positive and 41 HPV58-positive cases. HPV33 variants were more frequently observed in CINs I/II than in CIN III/ICCs (71% (5/7) versus 15% (2/13), P=0.02). In HPV52-positive cases, a single E6 variant was detected in 98% of the cases, whereas the prototype accounted for 98% of HPV58-positive cases. In summary, the distribution of E6 variants is different among HPV types tested, suggesting a link between E6 variation and oncogenic potential being type-specific.

Positive peritoneal cytology in endometrial cancer: enhancement of other prognostic indicators

OBJECTIVE

The goal of this study was to investigate the prognostic significance of positive peritoneal cytology in endometrial cancer.

METHODS

A clinicocytopathological study was performed in 534 patients with endometrial cancer to assess the prognostic value of positive peritoneal cytology. The study population was divided into three groups: a low-risk group (disease limited to the uterus, grade 1, and depth of invasion < or =1/2), a moderate-risk group (disease limited to the uterus, grade 2 or 3, and/or depth of invasion >1/2), and a high-risk group (extrauterine disease). In each group, disease-free survival was compared in the patients who were positive or negative for malignant cells.

RESULTS

The overall incidence of positive peritoneal cytology was 22.3% (119/534). The 5-year disease-free survival of patients positive or negative for malignant cells was 98.1% versus 100% in the low-risk group (n = 250), 77.5% versus 91.3% in the moderate-risk group (n = 211), and 42.9% versus 72.1% in the high-risk group (n = 73). A significant difference was noted in the moderate-risk (P = 0.044) and high-risk (P = 0.015) groups, but not in the low-risk group (P = 0.56).

CONCLUSIONS

Positive peritoneal cytology is not a negative prognostic indicator itself, but it potentiates other prognostic indicators for endometrial cancer. Our findings also suggest that patients with positive peritoneal cytology in the absence of other adverse prognostic factors do not need upstaging.

Identification of a high-risk subgroup in cytology-positive stage IIIA endometrial cancer

OBJECTIVE

To identify a high-risk subgroup among patients with cytology-positive stage IIIA endometrial cancer.

STUDY DESIGN

Fifty-four stage IIIA endometrial cancer patients who were positive only on peritoneal cytology were divided into two groups based on the cytologic pattern of their peritoneal smears. In group A, malignant cell clusters had well-defined edges, while the tumor cell clusters had scalloped edges in group B. The prognostic significance of these findings was investigated.

RESULTS

The five-year disease-free survival rate was 97.5% in group A (n=40) versus 50% in group B (n = 14). Multivariate analysis confirmed that the cytologic pattern had an independent influence on survival.

CONCLUSION

Positive peritoneal cytology composed of malignant cell clusters with well-defined edges has no impact on survival. Only endometrial cancer patients who show tumor cell clusters with scalloped edges in peritoneal smears are worth considering for upstaging.

Effects of ipriflavone on bone loss following a bilateral ovariectomy and menopause: a randomized placebo-controlled study

A randomized placebo controlled study was undertaken to evaluate the effect of ipriflavone (IP) against the bone loss in premenopausal ovariectomized women and postmenopausal women. Thirty-seven Japanese women who underwent premenopausal bilateral ovariectomy within 3 months (early stage group) and 52 Japanese women who were ovariectomized or who had undergone menopause more than 3 years before the start of the study (late stage group) were enrolled. The patients were randomly allocated into two groups: those who received IP (600 mg/day) and those who received placebo. The bone mineral density (BMD) of the lumbar vertebrae was measured by dual energy X-ray absorptiometry, and the markers of bone metabolism were measured at the same time that BMD was measured. In the early stage group, the IP group showed a 6.7% decrease in BMD from baseline levels, whereas the placebo group showed a 10.7% decrease (P < 0.01) at 12 months of treatment, and 7.1% and 12.6% decrease at 24 months of treatment, respectively (P < 0.01). In the late stage group, there was a 0.3% increase in BMD in the IP group and a 2.3% decrease in the placebo group at 6 months of treatment (P < 0.01), and similar changes were seen at 18 months (1.4% increase and 3.9% decrease; P < 0.01). IP suppressed bone loss compared with placebo, however, did not prevent acute bone loss in the early stage following ovariectomy. The effect of IP alone on bone loss in the early stage is not sufficient to reduce the risk of osteoporosis in later life.

Müllerian adenosarcoma of the uterus: report of a case with imprint cytology

BACKGROUND

Müllerian adenosarcoma is a rare morphologic variant of uterine sarcoma that, although well described histologically, is scarcely mentioned in the cytologic literature.

CASE

A 75-year-old female was suspected of having atypical endometrial hyperplasia on an endometrial smear. However, subsequent imaging techniques revealed the presence of a bulky, polypoid mass filling the uterine cavity. On pathologic examination of the hysterectomy specimen, the polypoid tumor was diagnosed as mullerian adenosarcoma, homologous, with sarcomatous overgrowth, in which the sarcomatous component was compatible with high grade endometrial stromal sarcoma. Imprint smears of the tumor consisted of two morphologic patterns, sarcomatous and glandular. The sarcomatous tumor cells, with coarse chromatin and relatively scant cytoplasm, formed small aggregates or appeared alone. These cells were semiround or oval and had conspicuous nucleoli. In addition to these observations, small and large clusters of glandular cells with mild atypism were interspersed with the sarcomatous cells.

CONCLUSION

Cytologic examination of müllerian adenosarcoma well reflects its pathologic features.

Importance of NF-kappaB in rheumatoid synovial tissues: in situ NF-kappaB expression and in vitro study using cultured synovial cells

OBJECTIVES

To examine whether inhibition of NF-kappaB induces apoptosis of human synovial cells stimulated by tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta), and anti-Fas monoclonal antibody (mAb).

METHODS

The expression of proliferating cell nuclear antigen (PCNA), NF-kappaB, and the presence of apoptotic synovial cells were determined in synovial tissues. Apoptosis of cultured synovial cells was induced by inhibition of NF-kappaB nuclear translocation by Z-Leu-Leu-Leu-aldehyde (LLL-CHO). The activation of caspase-3 and expression of XIAP and cIAP2 in synovial cells in LLL-CHO induced apoptosis was also examined.

RESULTS

Abundant PCNA+ synovial cells were found in rheumatoid arthritis (RA) synovial tissue, though a few apoptotic synovial cells were also detected in the RA synovial tissues. Nuclear NF-kappaB was expressed in RA synovial cells. Electrophoretic mobility shift assay showed that treatment of cells with TNFalpha or IL1beta significantly stimulated nuclear NF-kappaB activity. A small number of apoptotic synovial cells expressing intracellular active caspase-3 were found after treatment of cells with LLL-CHO. Although treatment of RA synovial cells with TNFalpha or IL1beta alone did not induce apoptosis, apoptosis induced by LLL-CHO and caspase-3 activation were clearly enhanced in TNFalpha or IL1beta stimulated synovial cells compared with unstimulated synovial cells. Furthermore, induction of apoptosis of synovial cells with caspase-3 activation by anti-Fas mAb was clearly increased by LLL-CHO. The expression of cIAP2 and XIAP in synovial cells may not directly influence the sensitivity of synovial cells to apoptosis induced by LLL-CHO.

CONCLUSION

The results suggest that NF-kappaB inhibition may be a potentially important therapeutic approach for RA by correcting the imbalance between apoptosis and proliferation of synovial cells in RA synovial tissue.

Lipopolysaccharide of Burkholderia cepacia and its unique character to stimulate murine macrophages with relative lack of interleukin-1beta-inducing ability

Lipopolysaccharide (LPS) of Burkholderia cepacia was purified by the conventional phenol-water extraction method (preparation BcLPS-1), followed by enzymatic treatments with DNase, RNase, trypsin, and proteinase K (preparation BcLPS-2), and finally by deoxycholate-phenol-water extraction (preparation BcLPS-3). Cells of LPS-hyporesponsive C3H/HeJ mice were activated by both the BcLPS-1 and the BcLPS-2 preparations but barely activated by BcLPS-3. When LPS-responsive C3H/HeN mice were used as targets, endotoxic activities such as lethal toxicity to galactosamine-sensitized mice, mitogenicity to spleen cells, and activation of macrophages to induce tumor necrosis factor alpha and interleukin-6 (IL-6) were strongly exhibited even by highly purified BcLPS-3 at levels comparable to those of the highly active enterobacterial LPS of Salmonella enterica serovar Abortus-equi (SaeLPS), used as the control. The ability of BcLPS-3 to activate murine macrophages for induction of IL-1beta was, however, much weaker than that of SaeLPS. Both accumulation of pro-IL-1beta protein and expression of IL-1beta mRNA in macrophages by stimulation with BcLPS-3 were much weaker than by stimulation with SaeLPS. These results indicate that LPS of B. cepacia has the potential to play a role as a pathogenic factor with strong activity comparable to that of usual enterobacterial LPS, but unlike the latter, this LPS has a relative lack of ability in the activation of murine macrophages to induce IL-1beta. The lack of IL-1beta-inducing ability appears to be caused by incomplete signal transduction somewhere in the upstream step(s) of IL-1beta gene transcription.

Localization of a novel susceptibility gene for familial ovarian cancer to chromosome 3p22-p25

We performed genome-wide linkage analysis in 58 patients and nine unaffected members among 28 families with no mutation in BRCA1 or BRCA2, employing a set of 410 microsatellite markers. We initially screened the whole genome, including the X chromosome, by a non-parametric method using the GENEHUNTER program. As a result, chromosome 3p22-p25 showed a suggestive score for linkage [LOD = 3.49 and non-parametric LOD (NPL) = 2.77 at D3S3611] based on a multipoint analysis. Additionally, based on a two-point analysis using dense markers, this 3p22-p25 region showed a P-value < 0.05 at 10 markers and there is suggestive evidence for linkage at two markers within approximately 19 cM (NPL = 2.60 and 2.49 at D3S1597 and D3S3611, respectively). To explore whether the candidate gene in this 3p22-p25 region contributed to carcinogenesis of familial ovarian cancer in a similar fashion to the tumor suppressor gene, we performed loss of heterozygosity (LOH) analysis. It was observed that the frequency of LOH at four markers in this region was >50% only in tumor tissues from patients with no mutation in BRCA1 or BRCA2, not in those with a BRCA1 mutation.

Influence of different acid conditioners on the tensile bond strength of 4-META/MMA-TBB resin to Er:YAG laser-irradiated bovine dentin

PURPOSE

This study evaluated the effect of acid conditioners on resin bonding to dentin following irradiation with an Er:YAG laser and investigated the characteristics of resin bonding to the laser-treated dentin.

MATERIALS AND METHODS

Extracted bovine teeth were cervically sectioned to expose a dentin surface. After polishing, the dentin was irradiated with an Er:YAG laser. Aqueous solutions of 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3) were then applied to the laser-treated surface as acid conditioners. After the acid treatment, a PMMA rod was bonded to the irradiated dentin using 4-META/MMA-TBB resin, and miniaturized dumbbell-shaped bonded specimens were prepared. These specimens were subjected to tensile testing, and fractured surfaces were observed with field-emission scanning electron microscopy (FE-SEM) to determine the mode of fracture. Additionally, the resin-dentin interfaces were observed under FE-SEM.

RESULTS

The tensile bond strength of acid-conditioned bonded specimens was lower than that of specimens not subjected to acid treatment (11.1 MPa) in the laser-irradiated group. No significant difference was observed between 10-0 and 10-3 treatments. 10-3 treatment yielded the highest bond strength (24.6 MPa) in the nonirradiated group, as opposed to only 7.7 MPa in the laser-treated group. Cohesive failure in the dentin was observed in almost all specimens in the irradiated group. Furthermore, a 10- to 30-micron-thick resin-penetrated layer was observed at the interface between the dentin and resin.

CONCLUSION

These results suggest that the effect of acid conditioners on resin bonding to dentin differs according to whether the dentin has been laser irradiated or not.

[Prediction of the need for mechanical ventilation after transsternal thymectomy in patients with myasthenia gravis]

Between June 1992 and May 2000, transsternal extended thymectomy was performed for 70 patients with myasthenia gravis in our hospital. We were able to evaluate 64 of them in terms of prediction of the need for postoperative mechanical ventilation using the score systems reported by Leventhal et al., Kimura et al. and the criteria of Adachi et al.. For these systems, the rates of agreement between predictions and results were 85.9%, 82.8%, and 64.1%, respectively. The two former systems had some false negative cases (i.e., they predicted that ventilation would not be needed when in fact it was), but the last one gave no false negatives. We recommend Adachi's criteria for clinical safety. In our cases the patients whose value of %VC multiplied by FEV1.0% was less than 7,000 (Adachi's criterion is less in 8,300), especially, needed careful management with regard to respiratory crisis.

X-irradiation induces up-regulation of ATM gene expression in wild-type lymphoblastoid cell lines, but not in their heterozygous or homozygous ataxia-telangiectasia counterparts

Ataxia-telangiectasia (AT) is an autosomal recessive disease. The relevant gene has been cloned and designated ATM. We studied the expression of both ATM mRNA and the ATM protein in unirradiated and X-irradiated EBV (Epstein-Barr virus)-transformed lymphoblastoid cell lines (LCLs) derived from donors who were normal (ATM + / + ), AT heterozygotes (ATM + / - ), or AT homozygotes (ATM - / - ), respectively. In ATM + / + LCLs, the levels of ATM mRNA were found to have increased by approximately 1.5-fold within 1 h of exposure to 10 Gy of X-rays, while the ATM protein levels had increased by 1.5- to 2.0-fold within 2 to 3 h of irradiation. The wild-type mRNA and protein levels both returned to their basal values fairly quickly after this time. The results obtained with the ATM + / - LCLs were quite different, however: neither the mRNA nor protein levels were found to have increased as a consequence of X-irradiation in any ATM + / - LCL. Twelve of the mutations in the ATM - / - LCLs we used were truncating mutations, and we suspected that the corresponding truncated ATM proteins would be too labile to be detected by western blot analysis. However, five of the ATM - / - LCLs produced mutant ATM proteins that were identical in molecular weight to the wild-type ATM protein. When cells from three of these five clones were exposed to X-rays, transcription of the mutant ATM genes appeared to reduce somewhat, as were the levels of protein being produced. These results suggest that the normal ATM gene responds to ionizing radiation by up-regulating its activity, whereas none of the mutant ATM genes we studied were able to respond in this way.

Malignant potential of positive peritoneal cytology in endometrial cancer

OBJECTIVE

To investigate the malignant potential of positive peritoneal cytology in endometrial cancer.

METHODS

Fifty patients with clinical stage I-II endometrial cancer in whom the disease was completely surgically resected and positive peritoneal smears were found at surgery formed the study population. In these patients, a tube for cytologic analyses was inserted into the peritoneal cavity when closing the abdomen. The peritoneal cavity was irrigated with physiologic saline, and washings were obtained through the tube 7 and 14 days after the operation.

RESULTS

Persistence of positive peritoneal cytology was observed in four of seven patients with adnexal metastasis, zero of nine patients with nodal disease, and one of 34 patients with disease confined to the uterus, for a total of 10% (5 of 50). In the remaining 45 (90%) patients, no malignant cells were found in any of the washings.

CONCLUSION

The current series suggests that endometrial cancer cells found in the peritoneal cavity usually disappear within a short time and seem to have a low malignant potential. It also seems that only malignant cells from special cases, such as adnexal metastasis, may be capable of independent growth, and are possibly associated with intraperitoneal recurrence.

Heart rate and mortality in a Japanese general population: an 18-year follow-up study

The predictive power of elevated heart rate for total mortality was evaluated in a Japanese general population. A total of 573 male participants, aged 40 to 64, who underwent a health examination in 1977, were followed until 1994. Heart rate (beats per minute; bpm) was measured using an electrocardiogram. During the 18 years, 82 subjects died; 18 from cerebro-cardiovascular diseases and 36 from cancer. In a multivariate proportional hazards regression model, age, elevated systolic and diastolic blood pressures, antihypertensive medication, heart rate, uric acid, vital capacity (inversely), and serum cholesterol (inversely) were significantly associated with all-cause death. Of these variables, elevated heart rate was the strongest predictor of all-cause death after adjustment for age. Resting heart rate levels were classified into five groups: < 60 (G1), 60-69 (G2), 70-79 (G3), 80-89 (G4), and > or = 90 (G5) bpm. Heart rates of 60-69 (G2) bpm showed the lowest death rate (14.3%) and heart rate > or = 90 (G5) bpm showed the highest death rate (38.2%) after adjustments for age and other confounding factors. The relative risk of G2 versus G5 was 2.68. An increased mortality risk was shown in men whose heart rate was > or = 90 bpm. Moreover, a continuous model suggested a graded increase in risk, so that risk is likely elevated even for heart rates less than 90 bpm, and lowest risk may be around 60 bpm.

Chromosomal instability in BRCA1- or BRCA2-defective human cancer cells detected by spontaneous micronucleus assay

The BRCA1 and BRCA2 gene products are believed to play an important part in the onset and/or development of many sporadic mammary cancers. Recently, it has been reported that these two proteins contribute to a centrosome function which is believed to help maintain the integrity of the chromosome segregation process. This may mean a reduced level of the BRCA1 or BRCA2 protein in mammary cells will occasionally lead to nondisjunctional chromosomal loss or gain. We now report that spontaneous micronuclei arising from chromosome(s) which fail to be incorporated into the relevant daughter nuclei during mitosis tend to occur more frequently in BRCA1- or BRCA2-defective human cancer cells than in BRCA-positive cancer cells. Some cases of mammary carcinogenesis may therefore stem from the loss of integrity of chromosome segregation in cells which have a reduced capacity to express either BRCA1 or BRCA2.

Is insulin resistance or diabetes mellitus associated with stroke? An 18-year follow-up study

Insulin resistance and/or diabetes are risk factors for coronary artery disease. However, it is still controversial whether they are associated with the development of stroke. A total of 304 Japanese men and women, aged 20-69 years, were selected on the basis of casual high blood glucose concentrations from 2732 participants of a population-based health examination in 1980. They all underwent a 50 g oral glucose tolerance test in 1981. Homa IR (index of insulin resistance) and Homa beta-cells (index of beta-cell function) were calculated from their fasting insulin and glucose using the formulas for the homeostasis model. They were followed-up for 18 years. Incidence of stroke was investigated by computed tomography. During 18 years, 28 subjects had a stroke; 21 had ischemic and nine had hemorrhagic strokes (two had both). Baseline variables, which showed an independent association with the incidence of stroke in the Cox proportional hazard model, were blood pressure, use of anti-hypertensive medications, and Homa beta-cell index (inversely) after adjustments for age and sex. After further adjustment for blood pressure using a step-forward method, Homa beta-cell was significantly related to the incidence of stroke (Hazard ratio: 0.65, 95% confidence interval: 0.44-0.95). In addition to hypertension, diabetes but not insulin resistance, is a risk factor for stroke.

Combined effect of rebamipide and ecabet sodium on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. We have reported that rebamipide and ecabet sodium, mucoprotective antiulcer agents, independently inhibit H. pylori adhesion. However, the antiadhesion activity of each antiulcer agent was incomplete. Experiments were performed to evaluate the combined effect of rebamipide and ecabet sodium on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Twelve clinical isolates of H. pylori were used in this study. We evaluated the effects of rebamipide and ecabet sodium, individually and in combination, on H. pylori adhesion to target cells quantitatively using our previously established enzyme-linked immunosorbent assay. Rebamipide and ecabet sodium each partially inhibited H. pylori adhesion. In contrast, adhesion was almost completely inhibited by pretreating target cells and H. pylori with the combination of rebamipide and ecabet sodium. Our studies suggest that the synergistic antiadhesion activity of rebamipide and ecabet sodium is greater than that of each antiulcer agent alone.

[Gastric mucosal immunity induced by H. pylori infection]

H. pylori infection induces various humoral and cellular immunities in gastric mucosa. Some reports indicate predominant CD4+ cells infiltrate in H. pylori infected gastric mucosa, and these cells express the T helper 1 phenotype. Local humoral immunity is also induced. Gastric plasma cells produce anti-H. pylori antibodies, however, their protective immunity is not enough to eradicate bacteria in human. We found heat shock protein 60 kDa (hsp60) may be closely associated with pathogenesis in MALT lymphoma. IgG1 antibodies to hsp60 were significantly correlated with the antibodies to H. pylori whole cell in patients with MALT lymphoma. CD40-CD40L dependent B cell proliferation was induced by cytokine and/or hsp60 stimulations in those patients. Cytotoxicity of gastric epithelial cells which is associated with host immunity induced by H. pylori infection is still unclear. We found that lymphocytes from patients with peptic ulcer showed cytotoxicity to gastric cell line HGC-27 in vitro. Cytotoxicity was enhanced by cytokine stimulus to T-lymphocytes and by heat stress and/or patients' antibodies treatment of HGC-27 cells. The pathogenicity of H. pylori may involve not only bacterial virulence factor but also host immunity. Studies of mucosal local immunity will help explain the mechanisms of H. pylori induced gastrodoudenal diseases.

Prognostic value of the colposcopic tumor size in stage IB squamous cervical cancer

BACKGROUND AND OBJECTIVES

To determine the prognostic significance of the colposcopic tumor size in the management of cervical cancer.

METHODS

Clinicopathological analysis was performed in 751 consecutive patients with stage IB squamous cervical cancer who were surgically treated in a single institute. The colposcopic tumor size was measured postoperatively on surgical specimens. Univariate and multivariate analyses were performed to determine the prognostic significance of various pathological factors.

RESULTS

Among the pathological factors examined, lymph node metastasis, parametrial extension, deep stromal invasion, vessel permeation, endometrial extension, and colposcopic tumor size were found to be prognostic factors in univariate analysis, whereas multivariate analysis has confirmed that only three factors, i.e., lymph node metastasis, parametrial involvement, and colposcopic tumor size were independently associated with the disease-free interval.

CONCLUSIONS

These results indicate that the colposcopic tumor size is an independent prognostic factor in squamous cervical cancer and can be used as an indicator of treatment options.

Effects of nitric oxide on matrix metalloproteinase-2 production by rheumatoid synovial cells

Nitric oxide (NO) is a multifunctional messenger molecule generated from L-arginine by a family of enzymes, including nitric oxide synthase (NOS). This study was performed to examine whether NO modulates the production of matrix metalloproteinases (MMPs), which degrade all components of extracellular matrix (ECM), in rheumatoid synovial cells. We investigated the effects of exogenously generated NO by a NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), on the MMPs production by rheumatoid synovial cells. Culture media conditioned by SNAP-treated synovial cells were examined by gelatin zymography and immunoblot analysis. Incubation of synovial cells with SNAP resulted in gelatinase A production in a dose-dependent fashion. Furthermore, RT-PCR analysis demonstrated that MMP-2 mRNA expression was induced in SNAP-treated synovial cells. In contrast, SNAP did not influence the production of TIMP-1 and TIMP-2, which preferentially inhibit MMP-2, by rheumatoid synovial cells. Our data indicate that NO could modulate MMP production by rheumatoid synovial cells and therefore contribute to ECM degradation of articular components in RA.

[Sensitivity and specificity of rapid diagnosis kit detecting separately influenza A and B viruses]

Sensitivity and specificity of the Directigen Flu A + B kit, a rapid test for influenza virus A and B, were evaluated. This test detects influenza A and B viruses separately by EIA. Reactivity of the kit was tested using a total of 23 isolates: 13 isolates of human influenza virus A (H1N1, H3N2) and 10 isolates of human influenza virus B. All of the isolates were tested positive and no difference in reactivity was found in antigenic variables and subtypes. The kit was only reactive to influenza virus A and B, not reactive to other viruses. Typical influenza A and B strains were tested for detection limit. 7.8 x 10(3) pfu/ml was a detection limit for influenza virus A (H1N1: Beijing/262/95), 4.7 x 10(4) pfu/ml for influenza virus A (H3N2: Kitakyusyu/159/93), and 3.1 x 10(4) pfu/ml for influenza virus B (Guangdong/05/94). The Directigen Flu A + B kit was a easy-to-use, rapid detection device and the kit has sensitivity and specificity equivalent to other diagnostic devices, suggesting the kit are useful in medical institutions.

The effect of biofiltration on red blood cells 2.3-diphosphoglycerate and pH

To investigate the effect of biofiltration (BF) on the ability of blood to supply oxygen to the peripheral tissues, a 2 week crossover study was conducted with bicarbonate hemodialysis (BcHD) and BF using 5 male patients with diabetic renal failure as subjects. BcHD and BF were performed for 4 h and 3.5 h per session, respectively. Blood gases, the pH of red blood cells (RBC-pH), and 2. 3-diphosphoglycerate in RBC (RBC-2.3DPG) were measured during each treatment. After a 2 week BF treatment, the plasma HCO3- at the beginning of BF was significantly higher than that of BcHD (p < 0.01), and the blood pH improved with an elevated plasma bicarbonate level (p < 0.05). The RBC-pH at the beginning of BF was higher than that of BcHD (p < 0.05) although the RBC-pH at the end of both therapies increased to similar levels. The RBC-2.3DPG during BcHD remained unchanged, but during BF significantly increased (p < 0.05). Metabolic acidosis was significantly improved by BF with its effect reaching to the RBC intracellular level. The improved metabolic acidosis might occur as a result of the increase in RBC-2.3DPG during BF. This increase in RBC-2.3DPG has the effect of reducing the affinity of oxygen for hemoglobin and allows more oxygen to be delivered to the peripheral tissues although the increase in RBC-pH by dialysis restricts the dissociation of oxygen from hemoglobin.

[The analysis of surgically treated pulmonary tuberculosis]

Between January 1990 and December 1999, thirteen patients with pulmonary tuberculosis underwent surgical management in our hospital. The purpose of surgery was classified into three groups: drug-resistant or persistent disease (7 patients), hemoptysis (3), and the others. We have no operative death, but have two late deaths due to postoperative persistent positive sputum and progressive tuberculosis infection. One patient relapsed one year and six months after operation and medical treatment was done successfully. Pulmonary resection is useful for localized pulmonary tuberculosis even drug-resistant cases.

Clinical value of tumor markers for early detection of recurrence in patients with cervical adenocarcinoma and adenosquamous carcinoma

OBJECTIVE

The clinical value of tumor markers for early detection of recurrence was investigated in 32 patients with cervical adenocarcinoma or adenosquamous carcinoma who had recurrent tumors.

METHODS

Serum levels of CA 125, CA 19-9, carcinoembryonic antigen (CEA), and squamous cell carcinoma antigen (SCC), in addition to clinical status at the time of recurrence were investigated.

RESULTS

Among the 32 patients, 26 had no symptoms at the time of recurrence. In 20 patients, elevated serum levels of tumor markers were the first sign of recurrence. In 21 patients with recurrent adenocarcinoma, the positive rates were 14% (CA 125), 62% (CA 19-9), 29% (CEA), and 5% (SCC). There were 71% of cases positive for CA 19-9 and/or CEA. In 11 patients with recurrent adenosquamous carcinoma, the corresponding positive rates were 37% (CA 125), 46% (CA 19-9), 64% (CEA), and 55% (SCC), with 100% positive for CA 19-9, CEA, and/or SCC.

CONCLUSIONS

The combination of CA 19-9 and CEA is probably the most promising for detection of recurrent cervical adenocarcinoma. For adenosquamous carcinoma, the additional use of SCC is recommended.

[Evaluation of adverse effects including neurotoxicity of combination chemotherapy with paclitaxel and carboplatin]

The adverse effects of combination chemotherapy with paclitaxel and carboplatin, including neurotoxicity, arthralgia and muscle pain, were evaluated in 21 patients (30 courses) using questionnaires of the Gynecologic Oncology Chemotherapy Joint Research Group. The scores of pain and numbness peaked from the third to fourth day of treatment. Although the pain score improved subsequently, the numbness score persisted at a high level. Compared to the first and second courses, the peak pain score was higher and persisted for a longer duration in the fifth and sixth courses. Using the questionnaires, we were able to recognize a high incidence of numbness and pain in patients on combination chemotherapy with paclitaxel and carboplatin, and identify the degree and temporal changes of the adverse effects. Our results suggest that the questionnaires used in this study are clinically useful for evaluating the degree and clinical course of pain and numbness in anticancer chemotherapy.

Site-specific integration of an adeno-associated virus vector plasmid mediated by regulated expression of rep based on Cre-loxP recombination

Recombinant adeno-associated virus (AAV) type 2 has attracted attention because it appears to have the potential to serve as a vector for human gene therapy. An interesting feature of wild-type AAV is its site-specific integration into AAVS1, a defined locus on chromosome 19. This reaction requires the presence of two viral elements: inverted terminal repeats and Rep78/68. Accordingly, current AAV vectors lacking the rep gene lack the capacity for site-specific integration. In this report, we describe the use of Cre-loxP recombination in a novel system for the regulated, transient expression of Rep78, which is potentially cytotoxic when synthesized constitutively. We constructed a plasmid in which the p5 promoter was situated downstream of the rep coding sequence; in this configuration, rep expression is silent. However, Cre circularizes the rep expression unit, directly joining the p5 promoter to the 5' end of the rep78 coding sequence, resulting in expression of Rep78. Such structural and functional changes were confirmed by detailed molecular analysis. A key feature of this system is that Rep expression was terminated when the circular molecule was linearized and integrated into the chromosome. Using this regulated expression system, we attempted site-specific integration of AAV vector plasmids. A PCR-based assay and analysis of fluorescence in situ hybridization showed that the AAV vector sequence was integrated into chromosome 19. Sequence analysis also confirmed that transient expression of Rep78 was sufficient for site-specific integration at the AAVS1 locus, as is observed with integration of wild-type AAV.

Chromosomal localization of 18S rDNA and telomere sequence in the aye-aye, Daubentonia madagascariensis

Chromosomal localization of 18S rDNA and telomere sequence was attempted on the chromosomes of the aye-aye (2n = 30) using fluorescence in situ hybridization (FISH) and primed in situ labeling (PRINS), respectively. The rDNA was localized at the tip or whole of the short arm of acrocentric chromosomes 13 and 14 in all spreads observed. However, post-FISH silver-nitrate (Ag) staining showed that transcriptional activity of the rRNA genes was variable, particularly in chromosome 14, which was most frequently negative in one homologue carrying the smaller copy number of rDNA. This observation supports, at the molecular cytogenetic level, previous data concerning the relationship between the copy number of rDNA and its trancriptional activity. On the other hand, telomere sequence was localized only at the telomeric region of all chromosomes, the so-called telomere-only pattern, a characteristic similar to that of the greater bushbaby. These data may provide information on the chromosomal evolution of the lemur, because locations of rDNA and telomere sequences frequently offer important clues in reconstruction of karyotype differentiation.

[Effect of alcohol intake on dietary habits and obesity in Japanese middle-aged men]

The amount of alcohol intake has been increasing in Japan. We investigated whether this might affect dietary habits in middle-aged men. In 1989, we conducted a health examination of 809 Japanese males aged 40-69. Food and nutrient intakes were estimated from 24-hour dietary recall. Mean values of total energy, protein, fat, and carbohydrate were evaluated according to alcohol intake. Consumption of total calories and proteins, especially animal proteins, increased and carbohydrate intake decreased proportionately with the amount of alcohol intake. Meat, fish, and soybean intake were increased in heavy drinker, along with niacin, sodium, and phosphorus intake. Despite their higher caloric intake, moderate and heavy drinkers were not more obese than non- or light-drinkers. Japanese heavy drinkers took more animal protein and sodium instead of carbohydrate compared to non- and light- drinkers. In our series, heavy drinking was not related to obesity.

Involvement of spindles of an entomopoxvirus (EPV) in infectivity of the EPVs to their host insect

The biological function of entomopoxvirus (EPV) spindles (inclusion bodies that lack virions), has not been elucidated. We characterized the function of EPV spindles in the cupreous chafer, Anomala cuprea (Coleoptera: Scarabaeidae). Spheroids or spheroids mixed with spindles of Anomala cuprea EPV were administered per os to the A. cuprea larvae. A significant increase in infectivity was induced by the addition of spindles to the spheroids, strongly suggesting that the spindles play an important role in the infection of the host insect.

An anomalous case of the hepato-spleno-mesenteric and the gastro-phrenic trunks independently arising from the abdominal aorta

This report describes an arterial anomaly case in the celiaco-mesenteric region, which was encountered in a Japanese male cadaver in the dissecting room at Kurume University School of Medicine in 1999. In this case, the usual celiac trunk was not identified, and the hepato-spleno-mesenteric and the gastro-phrenic trunks were independently arising from the abdominal aorta. In addition, the common hepatic artery divided into the left hepatic, the right hepatic, and the gastroduodenal arteries simultaneously, then, the accessory gastric artery arose from the left hepatic artery. This type of arteral anomaly belongs to the Type III of Adachi's classification and the Type II of Morita's classification.

Enhanced oncogenicity of human papillomavirus type 16 (HPV16) variants in Japanese population

To investigate whether HPV16 E6 variants carry an elevated risk for cervical cancer in Japanese population, we investigated the E6 sequence variation in 40 cervical intraepithelial neoplasias (CINs) I-III and 43 invasive cervical cancers (ICCs), all positive for HPV16. HPV16 E6 variants were frequently found in ICCs than in CINs (88 vs. 65%, P=0.01). The E6 D25E, a rare variant in Western countries, was most frequently observed in ICC (44%). CIN I/II lesions with HPV16 variants were less likely to regress than those with HPV16 prototype (P=0.048). The finding that HPV16 E6 variants represent a significant risk factor is common between Western and Japanese women despite the different distribution of each variant.

Palladium(II)-catalyzed cyclization of urethanes and total synthesis of 1-deoxymannojirimycin

The palladium(II)-catalyzed cyclization of the urethane 8, which was derived from D-mannitol, gave the cyclic compound 9 with excellent diastereoselectivity. During these transformations, the Pd(II) species are not reduced and thus the catalyst can recycle without its reoxidation. The cycloadduct 9 was converted to 1-deoxymannojirimycin.

19F NMR study of protein-induced rhombic perturbations on the electronic structure of the active site of myoglobin

A novel C2-symmetric ring-fluorinated hemin, 13,17-bis(2-carboxyethyl)-2,8,12,18-tetramethyl-3,7-difluoroporphyrin atoiron(III), has been synthesized and was incorporated into sperm whale apomyoglobin to investigate protein-induced rhombic perturbations on the electronic structure of the active site of myoglobin (Mb) using 19F NMR spectroscopy. NMR signals for 19F atoms introduced as substituents on the present heme in ferrous low-spin and high-spin and ferric low-spin complexes have been observed and their shifts sharply reflect not only the electronic nature of the heme iron, but also in-plane asymmetry of the heme electronic structure. The two-fold symmetric electronic structure of the ring-fluorinated hemin is clearly manifested in the 19F and 1H NMR spectra of its dicyano complex. The chemical equivalence of the two fluorine atoms of the heme is removed in the active site of myoglobin and the splitting of the two 19F NMR signals provides a quantitative probe for characterizing the rhombic perturbation of the heme electronic structure induced by the heme-protein interaction. The in-plane asymmetry of heme electronic structures in carbon-monoxy and deoxy Mbs have been analyzed for the first time on the basis of the shift difference between the two 19F NMR signals of the heme and is interpreted in terms of iron-ligand binding and/or the orbital ground state of the heme. A potential utility of 19F NMR, combined with the use of a symmetric fluorinated hemin, in characterizing the heme electronic structure of myoglobin in a variety of iron oxidation, spin, and ligation states, is presented.

The role of obesity in the association of cardiovascular risk factors and glucose intolerance in small Japanese and North American communities

To investigate whether the influence of obesity on cardiovascular risk factors and glucose intolerance differs between Japan and the US, we conducted cross-sectional surveys in those with elevated plasma glucose in Tanushimaru, Japan, and a stratified random population sample, in Wadena, MN. Subjects numbered 204 in Tanushimaru and 334 in Wadena. Body mass index (BMI), blood pressure, blood lipids, fasting plasma levels of glucose, glycosylated hemoglobin A(1c,) insulin, and free fatty acids were assessed. Overweight was defined as BMI of 27.5-29.9 kg/m(2) and obesity as BMI> or =30 kg/m(2). Gradual increases in risk factors were seen as BMI increased in both studies. Most risk factors were associated with glucose intolerance, except for BMI in Tanushimaru. In Wadena, glucose intolerance increased sharply among the obese. Adjustment for BMI attenuated the associations of cardiovascular risk factors with glucose intolerance in Wadena, but not in Tanushimaru. Obesity has an exaggerated influence on risk factors, compared with being overweight. The associations of glucose intolerance with cardiovascular risk factors are more affected by adjustment for BMI in Wadena than in Tanushimaru, not because of a different influence of body weight on risk factors between the two cities, but because obesity is rare in Japan.

[A resected case of large cell neuroendocrine carcinoma]

Large cell neuroendocrine carcinoma (LCNEC) is a rare lung cancer and it has a poor prognosis. We describe our experience with a patient in whom LCNEC was diagnosed. 38-year-old woman who complained of a cough and low grade fever up was admitted to our hospital. Chest X-ray and CT shoued 6.5 x 5.0 mass in rt-S1 and S2. It was suspected as LCNEC of the right lung because of broncopscopic cytology. The upper lobectomy of the right lung and desection of mediastinal lymph nodes were performed. Pathological diagnosis was III B (T2N2M0) LCNEC. Four weeks after the operation, one cycle of chemotherapy (CDDP + VP - 16 + VDS) and one cycle of chemoradiotherapy (thoracic radiation of 40 Gy, CDDP + 5 - FU) were performed. There are no findings of tumor recurrence 7 months after operation.

Antibody to heat shock protein can be used for early serological monitoring of Helicobacter pylori eradication treatment

Infection with Helicobacter pylori induces humoral immune responses against various antigens of the bacterium. Heat shock proteins (hsps) are immunodominant antigens in various diseases including H. pylori infection. In the present study, we measured the anti-hsp antibody titers in 42 patients with H. pylori-infected peptic ulcers during a bacterial eradication study. The patients were treated with a proton pump inhibitor and antimicrobial agents to eradicate the organism. Their sera were obtained at pretreatment and at 1 month and 6 months after the eradication therapy. The titers of immunoglobulin G antibodies to the H. pylori hsp, whole-cell lysate, and urease (30-kDa subunit) antigens in serum were measured by a capture enzyme-linked immunosorbent assay. The levels of H. pylori hsp60 antibodies in sera collected 1 month after treatment had declined significantly, even when changes in the titers of antibodies to whole-cell and urease antigens were not apparent. These results suggest that measurement of antibodies to H. pylori hsp60 in serum is useful for the early monitoring of the effectiveness of eradication therapy.

[Dental treatment for the handicapped by a combination of public community, dental association and university hospital--a system of Suginoki Dental Clinic]

Suginoki Dental Clinic, which is managed by Suginami Dental Association, financially supported by Suginami City, and technically assisted by the University Hospital, Tokyo Medical and Dental University, was established for dental treatment of handicapped persons living in Suginami City, Tokyo who are difficult to be treated by private practitioners. It has one full-time dentist, 12 part-time dentists, two dental hygienists, one nurse, and one clerk; one of the part-time dentists practices twice a week there. Since December 1994, 406 patients visited the clinic and the total cases was 9,273 in December 1999; 99 cases were mentally retarded, 36 autism, and 30 epileptic patients in the younger group; and 65 cases were cerebrovascular disease and 27 cardiac malfunction patients in the older group. Almost all the patients needed special care such as monitoring, intravenous sedation, nitrous oxide sedation, and general anesthesia. Four cases underwent general anesthesia, and no complication was seen among the cases. It was concluded that the clinic has been successful due to a good relationship among the Dental Association, Suginami City, and the dental hospital.

Technique to investigate the temporal phase shift between L- and M-cone inputs to the luminance mechanism

We describe a technique to estimate the intrinsic phase shift between long-wavelength-cone (L-cone) and middle-wavelength-cone (M-cone) signals in the luminance mechanism with minimal contamination by chromatic mechanism(s). The technique can also estimate, simultaneously with the phase shift, the weight ratio of L and M cones for the luminance mechanism. We measured motion identification thresholds for a 1.0 cycle/deg, 12.0-Hz sinusoidal grating representing different vector directions in L- and M-cone contrast space. The physical phase of the L- and M-cone signals was varied over a broad range between -150 deg and +150 deg to investigate the effect on the threshold contours. The slope of the threshold contour in cone contrast space varied as a function of the physical phase. Estimates of the intrinsic phase shift between L and M cones are based on the change in slope of the threshold contour. The estimates are consistent with previous reports and show that whereas the L-cone signal lags behind the M-cone signal by approximately 35 deg for an orange background, the M-cone signal lags behind the L-cone signal by approximately 8 deg for a green background.

Effect of Er:YAG laser irradiation on acid resistance to bovine dentin in vitro

Resin bond strength to Er:YAG laser irradiated dentin has been reported to be lower than that of unlased dentin. The reasons have been much discussed, but not clarified. One hypothetical cause has been discussed that lased dentin is acid resistant, therefore, the etching effect of acid conditions decreases. The purpose of this study was to evaluate the acid resistance of laser-irradiated dentin and compare it with the dissolved mineral of Er:YAG laser irradiated dentin and unlased dentin. This experiment was a pilot study to assess the etching effect of pre-conditioner for resin bonding to lased dentin. Bovine dentin was irradiated by Er:YAG laser and immersed in 0.1 M lactic buffer solution (pH 4.0). The dissolved Ca and P in the solution were then both measured. Dissolved Ca from lased dentin was not significantly different from that coming from unlased dentin (p > 0.05). The molar ratio of Ca/P did not differ significantly between lased and unlased dentin, either (p > 0.05). Under FE-SEM view before immersion, the dentin surface was covered with a smear layer in unlased dentin, but this layer was not clearly observed in lased dentin. These results suggested that the lased dentin had little or no resistance to lactic buffer solution.

Association between alcohol intake and development of hypertension in Japanese normotensive men: 12-year follow-up study

Although it has been suggested that alcohol intake is related to hypertension, few long-term prospective studies have investigated this relationship. We therefore conducted a prospective study in male residents of a farming community in Japan to determine whether heavy drinking would predispose to the development of hypertension. A total of 325 normotensive (< 140/90 mm Hg) men were enrolled in 1977. Twelve years later, 93 (28.6%) subjects became hypertensive (defined as blood pressure > or = 140/90 mm Hg or use of antihypertensive medication). The probability of the development of hypertension in heavy drinkers predicted from a logistic regression equation was 44.6% (relative risk: 2.05 versus nondrinkers) after adjusting for age and body mass index (BMI). It was 36.2% (relative risk: 1.86 versus nondrinkers) after a further adjustment for systolic blood pressure at baseline. A high odds ratio of 2.39 for the development of hypertension with alcohol intake of < 46 g/day versus > or = 46 g/day at baseline was obtained even after adjustments for age, BMI, and confounding factors. We conclude that habitual heavy drinking of alcohol is a risk factor for the development of hypertension. This is the first report demonstrating a significant relationship between habitual alcohol intake and the development of hypertension in a long-term prospective study in Japan.

Screening of BRCA1 mutation using immunohistochemical staining with C-terminal and N-terminal antibodies in familial ovarian cancers

We examined the subcellular localization of BRCA1 proteins using immunohistochemical staining with C-terminal (GLK-2 antibody) and N-terminal (Ab-2 antibody) monoclonal antibodies in 44 familial ovarian cancers. Among these, 24 cases were associated with 13 independent germ-line mutations of BRCA1, and loss of heterozygosity (LOH) at one or more BRCA1 microsatellite markers was found in all 21 informative tumors tested. With GLK-2 antibody, cytoplasmic staining was observed in 15 of 16 tumors (93.8%) with mutation in exon 11, and BRCA1 staining was absent in 8 of 8 tumors (100%) with mutation in exons other than exon 11. When immunohistochemical staining was performed with Ab-2 antibody, both nuclear and cytoplasmic staining were observed in 14 of 16 tumors (87.5%) with mutation in exon 11. Interestingly, nuclear staining was observed in 3 of 3 tumors (100%) with mutation downstream of exon 11, even though no staining was detected in 5 of 5 tumors (100%) with mutation upstream of exon 11. On the other hand, in familial ovarian cancers without BRCA1 mutations, nuclear staining or both nuclear and cytoplasmic staining was observed in 18 of 20 specimens (90%) and 20 of 20 specimens (100%) with GLK-2 antibody and with Ab-2 antibody, respectively. These results suggest that an immunohistochemical assay in combination with employing the C-terminal and the N-terminal antibodies appears to have potential as a reliable and useful technique for the screening of BRCA1 mutations, at least to predict the status of mutation, upstream or downstream of exon 11.

Regulation of rheumatoid synovial cell growth by ceramide

Overgrowth of rheumatoid synoviocytes, which results in joint destruction, is due to impaired balance between cell proliferation and cell death (apoptosis). Ceramide is an important lipid messenger involved in mediating a variety of cell functions including apoptosis. We investigated the effects of ceramide on growth-promoting anti-apoptotic signals in rheumatoid synovial cells. Human synovial cells isolated from patients with rheumatoid arthritis (RA) were stimulated with platelet-derived growth factor (PDGF) in the presence or absence of C2-ceramide. The kinase activity of Akt, MEK, and ERK1/2 was analyzed in PDGF-stimulated synovial cells by Western blot analysis. Pretreatment with C2-ceramide completely inhibited PDGF-induced cell cycle progression of rheumatoid synovial cells. PDGF stimulation induced phosphorylation and activation of Akt, MEK, and ERK1/2 in rheumatoid synovial cells. C2-ceramide inhibited the activation of Akt, MEK and ERK1/2 in PDGF-stimulated synovial cells. Our data demonstrated that inhibition of anti-apoptotic kinases, such as Akt and ERK1/2, may play an important role in ceramide-mediated apoptosis of rheumatoid synovial cells.

Induction of COX-2 expression by nitric oxide in rheumatoid synovial cells

Prostaglandins formed by cyclooxygenase (COX) enzymes are important mediators of inflammation. The contribution of inducible COX-2 in the rheumatoid synovium is well documented. In this study, we evaluated the contribution of nitric oxide (NO) to COX-2 expression in rheumatoid synovial cells. Exposure of rheumatoid synovial cells to a NO donor, SNAP, induced COX-2 protein expression in a dose-dependent manner. RT-PCR analysis also demonstrated that COX-2 mRNA was induced in SNAP-treated synovial cells. Dexamethasone at therapeutic concentrations markedly inhibited this NO-mediated COX-2 expression in synovial cells. In contrast to its effect on COX-2 expression, SNAP did not affect the constitutive expression of COX-1 in rheumatoid synovial cells. Our findings suggest that NO is an important modulator of COX-2 expression and that glucocorticoids exert their anti-inflammatory action in rheumatoid synovium, at least in part, by suppression of COX-2 induction.