Anti-cancer activity of highly purified sulfur in immortalized and malignant human oral keratinocytes.

Sulfur is commonly used in Asia as an herbal medicine to treat inflammation and cancer, and potent chemopreventive effects have been demonstrated in various in vivo and in vitro models for sulfur-containing compounds found in naturally occurring products. Here, we report the growth inhibitory and apoptosis-related effects of a newly developed highly purified sulfur (HPS) on immortalized human oral keratinocytes (IHOKs) and on oral cancer cells representing two stages of oral cancer (HN4, HN12) based on a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Western blotting, cell cycle analysis, and nuclear staining. The purity of the sulfur preparation was verified by high-performance liquid chromatography. HPS inhibited the proliferation of immortalized and malignant oral keratinocytes in a dose- and time-dependent manner. FITC-annexin V staining, DNA fragmentation testing, and Hoechst 33258 staining revealed that HPS inhibited cell growth via apoptosis. HPS increased the sub-G1 cell cycle fraction, with decreased expression of cyclins D1, D2, and E and their activating partners cdk2, cdk4, and cdk6, and a concomitant induction of p53 and p21/WAF1. Furthermore, HPS treatment increased the cytosolic level of cytochrome c and resulted in caspase-3 activation; this effect was correlated with Bax up-regulation and Bcl-2 down-regulation. Thus, these data suggest that HPS is a potential candidate for anti-cancer therapy in oral cancer.     

Mesenteric mass in a young girl – an unusual site for Gaucher's disease

We report the first case of a child with Gaucher's disease and a large mesenteric mass, confirmed histologically to be Gaucher's cell infiltrates. We describe the radiological findings and discuss further management. The advent of enzyme replacement therapy has prolonged survival and the emergence of previously undocumented manifestations of the disease is being observed. The radiologist and clinician should be alert to the possible development of these new problems and the fact that in Gaucher's disease a palpable right upper-quadrant mass need not necessarily represent hepatomegaly.     

Topoisomerase II-alpha (topoII) and HER2 amplification in breast cancers and response to preoperative doxorubicin chemotherapy

A significant proportion of breast cancers with HER2 amplification have simultaneous amplification of topoisomerase II-alpha (topoII). Amplification of HER2 and topoII was assayed using a novel chromogenic in situ hybridisation (CISH) method. HER2 and topoII amplification status and the response to preoperative doxorubicin chemotherapy were analysed in 67 locally advanced breast cancer patients. Response to chemotherapy was increased in the cases with coamplification of HER2 and topoII (18/19), whereas the response rate was significantly decreased in the cases without HER2 and topoII amplification (17/36). The 12 cases with HER2 amplification alone showed an intermediate response rate (9/12). The findings of the current study indicate that topoII amplification may play a role in determining chemosensitivity of breast cancers to doxorubicin chemotherapy.     

Insights into the role of DNA methylation in murine embryonic stem cells using a modified tetracycline-inducible gene expression system

Murine embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of the mouse blastocyst. Their ability to differentiate into diverse cell types in vitro has served well as a model of early embryonic developmental processes. A powerful strategy for studying the role of key genes during this time is to be able to regulate their expression in a dose-dependent manner. Here, we outline our experience of applying the "tetracycline-inducible system" to study gene function during ES cell differentiation and describe a number of key modifications designed to overcome the central problem of transgene silencing. Finally, we demonstrate how this approach can yield insights into the role of DNA methylation during ES cell differentiation by studying the function of two genes: DNMT3A, involved in the de novo methylation of cytosine bases, and MBD2b, a methyl-dependent co-repressor and putative cytosine demethylase.     

Role of COX-2, VEGF and cyclin D1 in mammary infiltrating duct carcinoma

Cyclooxygenase-2 (COX-2) has an important role in the promotion of carcinogenesis, tumor invasion and angiogenesis. Vascular endothelial growth factor (VEGF) is a proangiogenic factor that is up-regulated in various tumors. VEGF has been shown to interact with COX-derived prostaglandins in angiogenesis. Cyclin D1 gene overexpression and amplification have been shown to play a role as prognostic factors in many human cancers. To better understand the roles of these genes in mammary carcinoma, the immunohistochemical expression patterns of COX-2 and VEGF were evaluated in relationship with cyclin D1 overexpression, tumor stage, clinicopathologic parameters and patient survival in 128 mammary infiltrating duct carcinomas. The expressions of COX-2/VEGF, COX-2/cyclin D1, and VEGF/cyclin D1 were evaluated using double immunofluorescein staining with a confocal scanning laser microscope. A positive expression was seen in 41% for COX-2, 47% for VEGF, and 66% for cyclin D1 in the cases with breast cancer. There was correlation in positive expression of COX-2 or VEGF with histologic grade, lymph node metastasis, and tumor size. Conversely, a significant inverse relation was observed between VEGF and patient age. There was a correlation in overexpression of cyclin D1 with lymph node metastasis, survival rate and survival length. Significant correlations were observed between COX-2 and VEGF as well as COX-2 and cyclin D1. Co-expression of only COX-2 and VEGF was detected with significance. These results indicate that elevated COX-2 or VEGF expression or cyclin D1 overexpression is more common in breast cancer patients with poor prognostic characteristics and is partly associated with an unfavorable outcome. The present findings support the efforts to initiate clinical trials on the efficacy of COX-2 inhibitors in adjuvant treatment of breast cancer.     

Microsporidial keratoconjunctivitis in healthy individuals: a case series

PURPOSE: To present a series of 6 cases of microsporidial keratoconjunctivitis in healthy, nonimmunocompromised individuals. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Six individuals with unilateral keratoconjunctivitis. METHODS: Cornea epithelial scrapings were taken and evaluated by modified trichome staining. Blood was taken for human immunodeficiency virus (HIV) enzyme-linked immunosorbent assay in all cases and for CD4 and CD8 T-lymphocyte counts in 5 cases. MAIN OUTCOME MEASURES: The individuals were evaluated based on symptoms, visual acuity, slit-lamp biomicroscopy, and pathologic examination of the corneal scrapings. RESULTS: All cases occurred in men whose ages ranged from 16 to 37 years. Initial symptoms included unilateral pain and redness. All experienced subsequent worsening of symptoms and blurring of vision after using topical steroids prescribed by general practitioners. Slit-lamp biomicroscopy revealed coarse, multifocal, punctate epithelial keratitis in all 6 cases, anterior stromal infiltrates in 2 cases, with accompanying conjunctivitis in all cases. Modified trichrome staining of corneal epithelial scrapes revealed pinkish to red spores characteristic of microsporidia in all cases. Results of an HIV enzyme-linked immunosorbent assay were negative in all cases, and CD4 and CD8 T-lymphocyte counts and ratios were normal in all 5 tested cases. On diagnosis, topical steroid therapy was stopped in all cases. Treatment with topical Fumidil B (bicyclohexylammonium fumagillin; Leiter's Park Ave Pharmacy, San Jose, CA) together with oral albendazole was given in 3 cases, oral albendazole alone in a single case, and broad-spectrum antibiotic treatment with topical norfloxacin or chloramphenicol in two cases. Two cases had keratic precipitates with mild cellular activity in the anterior chamber and one such case was restarted subsequently on topical steroids. All six cases showed resolution of epithelial keratitis but with residual visually inconsequential subepithelial scars by the end of 1 month of treatment. CONCLUSIONS: Microsporidial keratoconjunctivitis can occur more commonly than expected in healthy, nonimmunocompromised individuals. Topical steroids seem to contribute to the persistence of this infection and may be a predisposing factor in these cases by creating a localized immunocompromised state. The clinical course is variable and may be self-limiting with cessation of topical steroid use.     

N-(3-acyloxy-2-benzylpropyl)-N'-[4-(methylsulfonylamino)benzyl]thiourea analogues: novel potent and high affinity antagonists and partial antagonists of the vanilloid receptor

Isosteric replacement of the phenolic hydroxyl group in potent vanilloid receptor (VR1) agonists with the alkylsulfonamido group provides a series of compounds which are effective antagonists to the action of the capsaicin on rat VR1 heterologously expressed in Chinese hamster ovary (CHO) cells. In particular, compound 61, N-[2-(3,4-dimethylbenzyl)-3-pivaloyloxypropyl]-N'-[3-fluoro-4-(methylsulfonylamino)benzyl]thiourea was a full antagonist against capsaicin, displayed a K(i) value of 7.8 nM (compared to 520 nM for capsazepine and 4 nM for 5-iodoRTX), and showed excellent analgesic activity in mice. Structure-activity analysis of the influence of modifications in the A- and C-regions of 4-methylsulfonamide ligands on VR1 agonism/antagonism indicated that 3-fluoro substitution in the A-region and a 4-tert-butylbenzyl moiety in the C-region favored antagonism, whereas a 3-methoxy group in the A-region and 3-acyloxy-2-benzylpropyl moieties in the C-region favored agonism.     

Lidocaine intoxication: Two fatal cases

We present two fatal cases, a 41-year-old male (case 1) and his 8-year-old daughter (case 2), resulting from acute lidocaine poisoning. Lidocaine was quantified by gas chromatography (GC) analysis using nitrogen-phosphorus detection. The lidocaine concentrations of cases 1 and 2 were: liver, 27.7 microg/g and 24.9 microg/g; spleen, 70.1 microg/g and 29.9 microg/g; and gastric contents, 23.6 microg/g and 42.8 microg/g, respectively.