Deep-sea in situ determination of sulfide using a sensitized chemiluminescent terbium complex.

A new chemiluminescence (CL) method based on the chemiluminescent reaction between sulfide and an acidic permanganate solution was used to quantify sulfide in seawater. A terbium-pipemidic acid complex was used as CL enhancer. The method was used to determine sulfide in the concentration range of 1-30 µmol/L in artificial seawater samples. The limit of detection of the method was 21 nmol/L sulfide. The sensitivity of the CL method was eight times higher than that of the CL method reported previously. Br- ions, which are conservative ions, interfered with sulfide. We investigated the effects of salinity, water temperature, and interfering chemicals,such asheavy-metal ions and organic matter, on the performance of the CL method. In addition, sulfite-spiked natural seawater samples were analyzed. The results demonstrate that the CL method can be used to develop a deep-sea sulfide analyzer.

Dynamic in vitro hemocompatibility of oligoproline self-assembled monolayer surfaces.

The blood compatibility of self-assembled monolayers (SAMs) of oligoproline, a nonionic antifouling peptide, was investigated using the cone-and-plate assay imitating arterial blood flow conditions. End-capped oligoprolines composed of 6 and 9 proline residues (Pro6 and Pro9) and a Cys residue were synthesized for preparing SAMs (Pro-SAMs) on Au-sputtered glass. The surface of Pro-SAMs indicated hydrophilic property with a smooth topology. The adsorption of blood components and the adhesion of blood cells, including leukocytes and platelets, were strongly suppressed on Pro-SAMs. Moreover, Pro9-SAM did not trigger the activation of platelets (i.e., the conformational change of GPIIb/IIIa and P-selectin (CD62P) expression on platelets and the formation of aggregates). Our results demonstrate that Pro9-SAM completely inhibited acute thrombogenic responses and the activation of platelets under dynamic conditions.

Surfaces immobilized with oligo-prolines prevent protein adsorption and cell adhesion.

In this study, oligo-prolines, (Pro)n (n = 6 and 9) inspired by the backbone structure of collagen, were evaluated as a novel non-ionic anti-fouling peptide. Two oligo-prolines with a cysteine residue were synthesized and immobilized on gold substrates via Au-thiol binding. The surfaces immobilized with oligo-prolines, and forming a polyproline-II conformation, indicated hydrophilic properties (water contact angle ≈ 25 degrees). The degree of adsorption of human serum albumin, human fibrinogen, and bovine serum components on these surfaces was quantified using a quartz crystal. The immobilization of oligo-prolines prevented the adsorption of proteins and serum components including small molecules, such as fatty acids. Pro9 specifically indicated good resistance to the adsorption of all components due to the highly-packed Pro9 chains on the surface. The adhesion of fibroblasts was drastically suppressed on the surfaces immobilized with oligo-prolines. Our findings suggest that oligo-proline-immobilized surfaces, specifically Pro9-s, are useful for the development of novel vascular devices that have ultra-low fouling properties.

In vitro osteoclast formation and resorption of silicon-substituted hydroxyapatite ceramics.

Materials that participate in bone remodeling at the implant/tissue interface represent a modern tissue engineering approach with the aim of balancing implant resorption and nascent tissue formation. Silicon-substituted hydroxyapatite (SiHA) ceramics are capable of stimulating new bone formation, but little is known about their interaction with osteoclasts (OC). The effects of soluble silicate and SiHA on OCs were investigated in this study. Soluble silicate below 500 µM did not stimulate cell metabolism at 4 days or alter resorption area at 7 days on calcium phosphate discs. On sintered ceramics, OC numbers were similar on HA, Si0.3 HA (0.5 wt % Si) and Si0.5 HA (1.2 wt % Si) after 21 days in vitro, but actin ring sealing zone morphology on SiHA resembled that commonly found on bone or on carbonate-substituted hydroxyapatite (CHA). Smaller and thicker actin rings on SiHA as compared to HA were probably the result of altered surface chemistry and solubility differences. The more stable sealing zones and increased lattice solubility likely contributed to increased individual pit volumes observed on Si0.5 HA. The delayed formation of OCs on Si0.5 HA (lower numbers at day 14) excludes earlier differentiation as a possible mechanism of increased individual OC pit volumes at later times (day 21). Materials characterization of Si containing biomaterials remains paramount as the Si type and amounts can subsequently impact downstream OC behaviour in a complex manner.

Determination of sulfide with acidic permanganate chemiluminescence for development of deep-sea in-situ analyzers.

A new chemiluminescence method is proposed for the determination of sulfide in seawater based on the chemiluminescence reaction between sulfide and an acidic permanganate solution. 3-Cyclohexylaminopropanesulfonic acid was used as a chemiluminescence enhancer. By use of this method, 1-150 µM of sulfide could be determined in artificial seawater. The limit of detection was 0.17 µM sulfide. We investigated the effects of salinity, water temperature, and interfering chemicals such as heavy-metal ions and organic matter. In addition, natural seawater spiked with sulfide was analyzed. The results showed that the CL method could be applied to a deep-sea sulfide analyzer.

Inhibition of Epidermal Growth Factor Receptor and PI3K/Akt Signaling Suppresses Cell Proliferation and Survival through Regulation of Stat3 Activation in Human Cutaneous Squamous Cell Carcinoma.

Recent studies have emphasized the important role of Stat3 activation in a number of human tumors from the viewpoint of its oncogenic and antiapoptotic activity. In this study, we examined the role and related signaling molecules of Stat3 in the carcinogenesis of human cutaneous squamous cell carcinoma (SCC). In 35 human cutaneous SCC samples, 86% showed overexpression of phosphorylated (p)-Stat3, and most of those simultaneously overexpressed p-EGFR or p-Akt. Constitutive activation of EGFR and Stat3 was observed in three SCC cell lines and four of five SCC tissues. AG1478, an inhibitor of the EGFR, downregulated Stat3 activation in HSC-1 human SCC cells. AG1478 inhibited cell proliferation and induced apoptosis of HSC-1 cells but did not inhibit the growth of normal human epidermal keratinocytes that did not show Stat3 activation. Furthermore, a PI3K inhibitor also suppressed Stat3 activation in HSC-1 cells to some degree. Combined treatment with the PI3K inhibitor and AG1478 strongly suppressed Stat3 activity and dramatically induced apoptosis of HSC-1 cells. These data suggest that Stat3 activation through EGFR and/or PI3K/Akt activation plays a critical role in the proliferation and survival of human cutaneous SCC.

E3710, a new proton pump inhibitor, with a long-lasting inhibitory effect on gastric acid secretion.

We have investigated the pharmacology of sodium (R)-2-[4-(2,2-dimethyl-1,3-dioxan-5-yl) methoxy-3,5-dimethylpyridin-2-yl]methylsulfinyl-1H-benzimidazol (E3710), a new proton pump inhibitor (PPI), and its effect on gastric acid secretion. E3710 irreversibly inhibited H(+),K(+)-ATPase activity in pig gastric vesicles with an acidic internal environment with an IC(50) of 0.28 microM. Administration of E3710 (0.1, 0.2, 0.4, and 0.8 mg/kg; n = 6) intraduodenally in a gastric fistula model in dogs inhibited histamine-stimulated gastric acid secretion at 0 to 2 and 24 to 26 h after administration with ED(50) values of 0.18 and 0.22 mg/kg, respectively. The inhibition by E3710 was 2.3 times more potent than that of another representative PPI, esomeprazole (0.2, 0.4, 0.8, and 1.6 mg/kg; n = 6) at 0 to 2 h after administration (ED(50) = 0.40 mg/kg) and 2.8 times more potent at 24 to 26 h (ED(50) = 0.71 mg/kg). In the gastric fistula dogs, the intragastric pH was >or=4 for 17% (n = 27) of a 24-h period with vehicle alone, but when E3710 was administered, at 0.2 (n = 4), 0.4 (n = 8), and 0.8 mg/kg (n = 5), the pH was >or=4 for 40, 79, and 88% of a day, respectively. The corresponding values for esomeprazole at 0.8 (n = 4) and 1.6 mg/kg (n = 8) were 55 and 59%, respectively. In a crossover study with vehicle, E3710 at 0.4 mg/kg and esomeprazole at 1.6 mg/kg (n = 6), E3710 increased the intragastric pH to >4 for 82% of a day compared with 61% of a day with esomeprazole. These results show that E3710 is a long-acting inhibitor of gastric acid secretion and a promising novel therapy for acid-related diseases, such as gastroesophageal reflux disease.

Ultraviolet light induces Stat3 activation in human keratinocytes and fibroblasts through reactive oxygen species and DNA damage.

Stat3 is activated by the outer stressors, such as ultraviolet (UV) exposure. In this study, we investigated the Stat3 response to UV irradiation in human epidermal keratinocytes and dermal fibroblasts. Results indicated that UVB and UVC differentially activate Stat3 in these cells. The UV-induced Stat3 activation was mediated by both reactive oxygen species (ROS) and DNA damage, and the dominancy of ROS and DNA damage to activate Stat3 depended on the wavelength of UV. By using fibroblasts from a patient with xeroderma pigmentosum A (XP-A) and those transfected with human XPA gene, we found that UVB activates Stat3 via both ROS and DNA damage, while UVC does so mainly via DNA damage. The present data suggest that Stat3 activation in UV-exposed human skin is one of the initial events where DNA damage and ROS are involved.

Melanophages reside in hypermelanotic, aberrantly glycosylated tumor areas and predict improved outcome in primary cutaneous malignant melanoma.

BACKGROUND: Previously, hypermelanotic regions of cutaneous malignant melanoma (CMM) were found to contain a mixture of highly melanized melanoma cells and melanophages. Both cell types produced beta1,6-branched oligosaccharides. These sugars are used for motility by myeloid cells and cancer cells alike and are associated with poor survival in carcinomas of the breast, colon and lung. This study further investigated associations between melanophages and beta1,6-branched oligosaccharides and their potential contributions to patient outcome. METHODS: Individual archival melanomas and high-throughput melanoma tissue microarrays were stained for melanophages with azure blue/S100 and for beta1,6-branched oligosaccharides with the lectin leukocytic phytohemagglutinin (LPHA, a selective marker for beta1,6-branched oligosaccharides). RESULTS: In primary CMM, melanophages were highly enriched in hypermelanotic, LPHA-positive tumor regions and correlated with improved outcome at 10- and 20-year follow ups. While the combination of melanophages, LPHA positivity and high pigmentation indicated better outcome, a subset of LPHA-positive cells not associated with melanophages indicated worse outcome. CONCLUSION: This is the first report of an anti-tumor role for the melanophage in melanoma biology. There appeared to be two classes of beta1,6-branched oligosaccharide-producing melanoma cells with opposing effects on outcome: one that attracted melanophages (better) and another that did not (worse). The findings disclose new aspects of the immune system and aberrant glycosylation in CMM.

Telomere length of the skin in association with chronological aging and photoaging.

BACKGROUND: Telomere shortening has been implicated in cellular senescence, which may cause certain aging phenotypes. OBJECTIVE: To reveal whether telomere shortening is associated with chronological aging and/or photoaging of the skin, we measured telomere length in the epidermis and in the dermis from sun-protected and from sun-exposed sites of the skin. METHODS: Seventy-six specimens of epidermis from sun-protected sites and 24 specimens of epidermis from sun-exposed sites were analyzed. Sixty specimens of the dermis were also analyzed. In six cases, epidermal specimens from sun-protected and from sun-exposed sites of the same individual were analyzed. RESULTS: Comparison of telomere lengths revealed that the epidermis has shorter telomeres than the dermis. Telomere length in the epidermis and in the dermis was reduced with age, and average telomere shortening rates in the epidermis and in the dermis were 9 and 11 bp/yr, respectively. Unexpectedly, telomere length was not significantly different between epidermis from sun-exposed sites and from sun-protected sites. CONCLUSION: We could not show the evidence that telomere shortening is associated with photoaging of the skin.

8-Oxoguanine formation induced by chronic UVB exposure makes Ogg1 knockout mice susceptible to skin carcinogenesis.

8-Oxoguanine is one of the oxidative DNA damages that can result in stable mutations. The Ogg1 gene encodes the repair enzyme 8-oxoguanine-DNA glycosylase, which removes the oxidized base from DNA. In this study, we investigated the role of 8-oxoguanine in skin carcinogenesis induced by UVB irradiation using Ogg1 knockout mice (C57Bl/6J background). We examined the effect of UVB irradiation on the formation of 8-oxoguanine in epidermal cells using immunostaining and found that the level of 8-oxoguanine in Ogg1 knockout mice 24 hours after UVB irradiation remained high compared with that in wild-type and heterozygous mice. To verify the effect of chronic UVB irradiation on 8-oxoguanine formations in epidermal cells, we irradiated wild-type, heterozygous, and Ogg1 knockout mice with UVB at a dose of 2.5 kJ/m2 thrice a week for 40 weeks. We found that the mean number of tumors in Ogg1 knockout mice was 3.71, which was significantly more than in wild-type and heterozygous mice, being 1.71 and 2.28, respectively. The rate of developing malignant tumors in Ogg1 knockout mice was also significantly higher (88.5%; squamous cell carcinomas, 73.1%; sarcomas, 15.4%) than in wild-type mice (50.0%; squamous cell carcinomas, 41.7%; sarcomas, 8.3%). Moreover, the age of onset of developing skin tumors in Ogg1 knockout mice was earlier than in the other types of mice. These results clearly indicate that oxidative DNA damage induced by sunlight plays an important role in the development of skin cancers.

Decreased expression of Apaf-1 with progression of melanoma.

Defects in apoptotic system may contribute in the pathogenesis and resistance of malignant melanoma cells to chemotherapy. Apoptotic protease-activating factor-1 (Apaf-1) is a cell death effector that acts with cytochrome c and caspase-9 to mediate apoptosis. Recently it was shown that metastatic melanomas often lose Apaf-1 and are concomitantly resistant to apoptosis. It is not known, however, whether Apaf-1 protein is lost during melanoma progression from localized to metastatic tumor. To this end, we evaluated Apaf-1 protein expression by immunohistochemistry in 10 cases of human nevi, 11 melanomas in situ, 26 primary melanomas and 15 metastases. Significant decreases in Apaf-1 expression was observed when comparing nevi and melanomas (chi-square = 33.719; P < 0.0001). Moreover, primary melanomas with greater tumor thickness showed lesser expression of Apaf-1 (chi-square = 16.182; P < 0.003). Intriguingly, we were unable to detect Apaf-1 expression in lesions of metastatic melanomas. These data demonstrated that there is an inverse correlation between Apaf-1 expression and pathologic stage of melanoma. This suggests that the decreased expression of Apaf-1 seen in correlation with melanoma progression renders melanoma more resistant to chemotherapy.

A case of generalized hair follicle hamartoma associated with systemic lupus erythematosus.

A hair-follicle hamartoma (HFH) may be localized or diffuse. Generalized HFH is frequently associated with an autoimmune disease such as myasthenia gravis or systemic lupus erythematosus (SLE). We report here a female patient with SLE who developed typical generalized HFH. This is the fourth case of generalized HFH associated with SLE.

Two cases of subcutaneous trichoblastoma.

This report concerns two Japanese women, 54 and 53 years old, with trichoblastoma. Histopathologically, these neoplasms were mainly composed of follicular germinative cells with fibrotic stroma. One of them was a giant lesion, but the other was small. Because both lesions were located in the subcutis, we termed them subcutaneous trichoblastoma.

Potentiometric performance of silver ion-selective electrodes based on tridentate Schiff base derivatives.

To examine the directivity for improving the silver ion discrimination ability of a Schiff base, three kinds of tridentate ligands were synthesized and compared with the similar quadridentate ligand as the silver ionophore. Among the Schiff base derivatives tested, 3-(2-pyridylethylimino)-2-butanoneoxime, having one oxime and a pyridine substituent, was found to be the best ionophore for a silver-ion electrode. The electrode based on this derivative exhibited good silver-ion selectivity, -log Kpot(Ag+,K+) = 3.8, comparable to that of a quadridentate Schiff base, N,N'-bis(2'-hydroxyimino-1'-phenylpropyleden)-1,3-propanediamine, reported previously, except for a pseudo Nernstian response (35.6 mV decade(-1)) with a wide silver-ion activity change in the activity change from 5.0 x 10(-7) to 7.9 x 10(-2) mol dm(-3).

Genistein enhances the cisplatin-induced inhibition of cell growth and apoptosis in human malignant melanoma cells.

Genistein, a naturally occurring isoflavone found chiefly in soybeans, has been reported to be a potent antitumor agent. Genistein is presumed to exert multiple effects related to the inhibition of cancer growth. Metastatic melanoma is a chemotherapy-refractory neoplasm. The present study was designed to explore the possible activity of genistein to inhibit the aberrant proliferation and to induce apoptosis of human malignant melanoma cells in cooperation with cisplatin treatment. Five human melanoma cell lines were utilized for these experiments. Genistein at physiologic concentrations (20 microM) did not induce apoptosis by itself but did enhance cisplatin-induced apoptosis in all five human melanoma cell lines tested. The enhanced susceptibility among the cell lines was diverse. Changes in the expression of two anti-apoptotic proteins, bcl-2 and bcl-xL, and one pro-apoptotic protein, apoptotic protease activating factor-1 (Apaf-1), were examined. Genistein alone or cisplatin alone generally did not alter bcl-2 expression or bcl-xL expression, but slightly increased Apaf-1 in some cell lines. The combined treatment with genistein and cisplatin significantly reduced bcl-2 and bcl-xL protein and increased Apaf-1 protein expression. These data suggest that genistein therapy may enhance the chemosensitivity of melanoma patients.

Human herpes virus 6 encephalitis in allopurinol-induced hypersensitivity syndrome.

Hypersensitivity syndrome is one of the most severe forms of drug eruption, and is characterized by a severe, potentially lethal, multiorgan involvement. Recently, reactivation of human herpesvirus 6 (HHV-6) has been suggested to be involved in this syndrome, although the exact role of HHV-6 remains elusive. In addition to exanthem subitum, neurological illnesses, such as infantile febrile illness without rash and encephalitis in immunocompromised patients have been attributed to HHV-6. A 51-year-old man developed a generalized erythematous eruption during treatment with allopurinol. Prednisolone improved his condition, but after the dose of prednisolone was reduced neurological abnormalities such as mental deterioration and positive meningeal signs developed. HHV-6 DNA in his blood by PCR analysis was positive. Furthermore, we detected HHV-6 DNA in the cerebrospinal fluid. The titers of anti-HHV-6-IgG increased during the course. His neurological symptoms gradually improved and no neurological sequelae were noted. Neurological abnormalities associated with hypersensitivity syndrome are very rare. However, the detection of HHV-6 DNA in the cerebrospinal fluid strongly indicates an involvement of reactivated HHV-6 in encephalitis.