Recent advances in layered double hydroxides applied to photoprotection / Recentes avanços dos hidróxidos duplos lamelares aplicados à fotoproteção

ABSTRACT Layered double hydroxides have received more attention from researchers due to their range of applications, ease of synthesis and low cost of production. With broader knowledge about solar radiation effects on the body, the use of sunscreens has become even more important. The ability of some nanostructures, such as layered double hydroxides, to act as matrices has made it possible to obtain improvements in photoprotective formulations, with solutions to problems caused by radiation and sunscreens. This review article brings together the most recent advances of these clays, the layered double hydroxides, applied to photoprotection.

RESUMO Os hidróxidos duplos lamelares vêm ganhando maior atenção de pesquisadores, em decorrência da gama de aplicações, da facilidade de síntese e do baixo custo de produção. Com o crescente conhecimento sobre diversos efeitos da radiação solar sobre o organismo, a utilização de fotoprotetores tem se tornado indispensável. A capacidade de nanoestruturas, como os hidróxidos duplos lamelares, atuarem como matrizes possibilitou melhorias nas formulações fotoprotetoras, tendo em vista os problemas provocados pela radiação, bem como por alguns filtros solares. Este artigo de revisão reúne os avanços mais recentes destas argilas, os hidróxidos duplos lamelares, aplicados à fotoproteção.

Enhanced apoptosis and inhibition of gastric cancer cell invasion following treatment with LDH@Au loaded Doxorubicin

Background: The suppression of cancer cell growth and invasion has become a challenging clinical issue. In this study, we used nanotechnology to create a new drug delivery system to enhance the efficacy of existing drugs. We developed layered double hydroxide by combing Au nanosol (LDH@Au) and characterized the compound to prove its function as a drug delivery agent. The anti-cancer drug Doxorubicin was loaded into the new drug carrier to assess its quality. We used a combination of apoptosis assays, cell cycle assays, tissue distribution studies, cell endocytosis, transwell invasion assays, and immunoblotting to evaluate the characteristics of LDH@Au as a drug delivery system. Results: Our results show that the LDH@Au-Dox treatment significantly increased cancer cell apoptosis and inhibited cell invasion compared to the control Dox group. Additionally, our data indicate that LDH@Au-Dox has a better target efficiency at the tumor site and improved the following: cellular uptake, anti-angiogenesis action, changes in the cell cycle, and increased caspase pathway activation. Conclusions: Our findings suggest the nano drug is a promising anti-cancer agent and has potential clinical applications.

Nanotube synthesis from reaction of 4-chloro phenoxy acetate with zinc layered hydroxide

Objective: Intercalations of plant growth regulator 4-chloro phenoxy acetate [4CPA] with zinc oxide [ZnO], developed using ZnO-layered hydroxide [ZLH] as host material and 4CPA as a guest

Methods: Ion exchange technique via sol-gel method synthesized under aqueous environment, resulted in the formation of inorganic-organic nanotube materials

Results: The release of 4CPA from its nanohybrid was found to occur in a controlled manner, governed by pseudo-second order kinetics model. The maximum amount of 4CPA released was governed by pseudo-second order kinetics model. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was developed with the increasing of 4CPA concentrations; the maximum concentration of 0.2M shows an interlayer basal of 1.9 nm. FTIR study showed that the intercalated 4CPA-ZnO spectral feature is generally similar to that of 4CPA, but with bands sightly shifted due to the formation of host-guest nanotubes

Conclusion: The resulted nanotubes were characterized by using scanning electron microscopy [SEM], and transmission electronic microscope [TEM], shows a uniform nanoparticles and monodisperse with average diameter of 35 nm, which correlated a very well with size scale obtained from XRD data. The development of crystals is the function of concentrations

Prevalence and Etiological Agents of Onychomycosis.

Onychomycosis is a common nail infection caused by dermatophytes, yeast or other non-dermatophyte molds and have been known to be associated with significant physical and psychological morbidity. This study was performed to determine the prevalence and the etiologic agents of onychomycosis in patients attending RIMS, Imphal, Manipur for a period of two years (January 2010 to December 2012). Nail samples of 347 clinically suspected cases of onycomycosis attending dermatology OPD RIMS, Manipur were collected and were subjected to potassium hydroxide (KOH) mounts for direct microscopy and fungal culture on Sabouraud’s dextrose agar (SDA). The male female ratio of the participants was 1:1.81 (165 male and 302 female). Out of 467, 399 (85.44.%) were positive by culture and KOH mount. Young adults in the age group of 21-30 years were commonly affected. In female patients finger nail infection was more common than toe nail infection. Both toe and finger nails involvement were noticed in nine patients of which two were male and seven were female. The most frequently isolated fungus was dermatophytes, in 107 (40.38%) patients followed by Aspergillus spp in 101 (38.11%) and Candida spp in 17 (6.4%). This study demonstrated that dermatophytes, as well as moulds especially Aspergillus spp are commonly isolated from onychomycosis patients in our region.

A prospective, open, comparative study of 5% potassium hydroxide solution versus cryotherapy in the treatment of genital warts in men

BACKGROUND: Genital warts are caused by human papillomavirus infection and represent one of the most common sexually transmitted diseases. Many infections are transient but the virus may recur, persist, or become latent. To date, there is no effective antiviral treatment to eliminate HPV infection and most therapies are aimed at the destruction of visible lesions. Potassium hydroxide is a strong alkali that has been shown to be safe and effective for the treatment of genital warts and molluscum contagiosum. Cryotherapy is considered one of the most established treatments for genital warts. No comparative trials have been reported to date on the use of potassium hydroxide for genital warts. OBJECTIVE: A prospective, open-label, randomized clinical trial was conducted to compare topical potassium hydroxide versus cryotherapy in the treatment of genital warts affecting immunocompetent, sexually active men. METHODS: Over a period of 10 months, 48 patients were enrolled. They were randomly divided into two groups and selected on an alternative basis for either potassium hydroxide therapy or cryotherapy. While response to therapy did not differ substantially between both treatment modalities, side effects such as local pain and post-treatment hypopigmentation were considerably more prevalent in the groups treated using cryotherapy. Result: In our study, potassium hydroxide therapy proved to be at least as effective as cryotherapy and offered the benefit of a better safety profile. CONCLUSION: Topical 5% potassium hydroxide presents an effective, safe, and low-cost treatment modality for genital warts in men and should be included in the spectrum of therapies for genital warts. .

Nerve Injury from Overfilled Calcium Hydroxide Root Canal Filling Paste for Maxillary Lateral Incisor Endodontic Treatment

Effect of calcium hydroxide application time on dentin

No abstract available.

Validation of Octanoate Breath Test for Measuring Gastric Emptying in Rats

BACKGROUND/AIMS: Lack of simple and repeatable tests hampers gastric emptying studies in rats. The aim of this study was to adapt the 14C-octanoate solid gastric emptying breath test for application in rats, and to validate it against radioscintigraphic method. METHODS: After ingestion of a meal containing 3 mCi 99mTc and 2 microCi 14C-octanoate, 23 male Wistar rats were placed on a gamma camera in a airflow container. Scintigraphic images were taken at regular intervals. The amount of 14CO2 in a regularly replaced hyamine hydroxide solution, capturing CO2 in the outflow air, was counted using liquid scintillation spectrometry. 99mTc gastric retention curves and 14CO2-excretion curves were fitted to their respective data. Three rats underwent the same procedures after administration of atropine. RESULTS: Overall Tr10% (time at which 10% of the original amount of 99mTc remained in the stomach) was 355 +/- 64 minutes; Te90% (time at which 90% of total amount of 14CO2 was excreted) was 325 +/- 106 minutes. Their correlation coefficient was 0.71, R-square 0.50 and P < 0.005. Tr1/2 (50% of original amount of 99mTc remained) was 124 +/- 28 minutes; Te1/2 (50% of total amount of 14CO2 excreted) 114 +/- 32 minutes. Their correlation coefficient was 0.83 with R-square of 0.69 and P < 0.00005. In 12 immobilized animals correlation was even better: correlation coefficient 0.84; R-square 0.71 and P < 0.001 (Tr10% was 388 +/- 117 minutes; Te90% 532 +/- 219 minutes; Tr1/2 of 165 +/- 54 minutes; Te1/2 of 175 +/- 67 minutes). Atropine significantly lengthened all emptying times: 904 +/- 307 and 1461 +/- 684 minutes for Tr10% and Te90%, respectively; and 432 +/- 117 minutes for Tr1/2 and 473 +/- 190 minutes for Te1/2. CONCLUSIONS: We adapted and validated the 14C-octanoate gastric emptying breath test for application in rats.

A Clinico-mycological Study of Onychomycosis with Dermatophytoma / 대한의진균학회지

BACKGROUND: Although there have been many studies about onychomycosis, the study about onychomycosis with dermatophytoma has not been reported yet in Korea. OBJECTIVE: The purpose of this study was to investigate the clinical characterictics and treatment strategies of the onychomycosis with dermatophytoma compare with the other onychomycosis. METHODS: In the 5-year period 2007-2011, we reviewed forty five patients with toenail onychomycosis with dermatophytoma, proven by direct potassium hydroxide examination. The etiological agents were identified by cultures on Sabouraud's dextrose agar with and without cycloheximide. To confirm dermatophytoma, we performed histopathologic evaluation of the nail plate by nail clipping. RESULTS: Toenail onychomycosis with dermatophytoma were 2.9% of all onychomycosis. Among the age groups, the incidence rate was highest in the sixties (24.4%). The ratio of male to female patients was 1:1.1. The frequency of associated disease was highest in diabetes mellitus (17.7%). The right great toenail was most common affected nails. Distal and lateral subungual onychomycosis (88.9%) was the most common clinical type. The round lesion was most common clinical features of affected area (66.7%), followed by linear lesion (33.3%). Trichophyton rubrum was most common etiological agent (57.8%). The partial removal of the tonail combined with oral and topical antifungal agent was most common in treatment of onychomycosis with dermatophytoma. CONCLUSION: Because of the increase in onychomycosis with dermatophytoma, and its relative resistance to the conventional treatment of onychomycosis, we suggest the need of a careful mycological examination to diagnose the dermatohpytoma in patients with onychomycosis, and we also propose more aggressive treatment strategy is required to treat dermatophytoma.

Onychomycosis Caused by Chaetomium globosum

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. The genus Chaetomium is a dematiaceous nondermatophytic mold found in soil and plant debris as a saprophytic fungus. We report the first Korean case of onychomycosis caused by Chaetomium globosum in a 35-year-old male. The patient showed brownish-yellow discoloration and subungual hyperkeratosis on the right toenails (1st and 5th) and left toenails (1st and 4th). Direct microscopic examination of scraping on the potassium hydroxide preparation revealed septate hyphae and repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide slants showed the same fast-growing colonies, which were initially velvety white then turned to dark gray to brown. However, there was no growth of colony on SDA with cycloheximide slants. Brown-colored septated hyphae, perithecia and ascospores were shown in the slide culture. The DNA sequence of internal transcribed spacer region of the clinical sample was a 100% match to that of C. globosum strain ATCC 6205 (GenBank accession number EF524036.1). We confirmed C. globosum by KOH mount, colony, and light microscopic morphology and DNA sequence analysis. The patient was treated with 250 mg oral terbinafine daily and topical amorolfine 5% nail lacquer for 3 months.

The Effects of Neutralization Therapy for Acute Alkali Ingestion in Rabbits

PURPOSE: To evaluate temperature changes in the gastric lumen and the efficacy of weak acid neutralization against the ingestion of a strong alkaline commercial agent. METHODS: A total of 23 male New Zealand White rabbits were anesthetized with an intramuscular injection of ketamine and xylazine. After gastric lavage, anoro-gastric catheter and an electric thermometer probe were inserted into the stomach. Then 3 mL/kg of room-temperature (24~26degrees C) 1M sodium hydroxide (NaOH) disinfectant was instilled into the gastric lumen. The rabbits were divided into three groups: Group 1 (n=8) was treated with NaOH only and Group 2 (n=7) and Group 3 (n=8) were treated with 39 mL/kg of room-temperature orange juice or water after 5 minutes, respectively. Intra-gastric temperature was continuously measured and compared with arterial pH before alkali insult and 30 minutes later. Gastric pH was measured, and pathological examination of the esophagus, stomach, and duodenum performed after animal sacrifice. RESULTS: Gastric lumen temperatures gradually increased from 32.6degrees C to 38.7degrees C after alkali instillation. Significant decreases in lumen temperature, 7.5degrees C or 12.0degrees C, were observed following treatment with water or orange juice, respectively (p<0.01). Post-treatment temperature did not exceed pre-treatment temperature for the entire observation period. The gastric pH of the neutralization group was much lower than the alkali alone group or the dilution group (7.0+/-0.7 vs. 11.6+/-0.2, or 10.6+/-0.4, respectively, mean+/-SD, p<0.01). In gastric microscopic findings, only mucosal injuries were observed in the neutralization groups, while there were no significant differences among groups in terms of esophageal or duodenal injury. CONCLUSION: Neutralization therapy with room-temperature orange juice for acute gastrointestinal injuries caused by liquid alkali did not cause additional thermal injury and might have protective effects against local tissue destruction in the stomach.

Retention of fiber posts to the optimally and over-prepared dowel spaces

PURPOSE: To assess the retention of glass fiber post cemented with self-adhesive resin cement into optimum and over-prepared root canals following obturation in the presence of either eugenol (EB) or calcium hydroxide (CB)-based sealers. MATERIALS AND METHODS: Roots of extracted premolars were endodontically-treated in 5 groups (n = 10). Roots of Group 1 (control) were left with no obturation and then optimally prepared to receive endodontic dowels. Other root canals were obturated with gutta-percha in the presence of either eugenol-based (Groups 2 and 4) or calcium hydroxide-based (Groups 3 and 5) sealer. Dowel spaces were prepared with optimal diameter in Groups 2 and 3, one size larger in Groups 4 and 5. Standardized fiber posts were luted to the prepared spaces using self-adhesive resin cement and itsretention was then tested on an universal testing machine. Both one-way ANOVA and Tukey's HSD comparisons (alpha=0.05) were used to identifythe significance of inter-group retention differences. Scanning electron microscopy (SEM) of both optimally and over-prepared dowel spaces was also considered to figure the nature of their interior out. RESULTS: The post retention was significantly higher to the non-obturated, optimally-prepared dowel spaces of Group 1 compared to the obturated, optimally-prepared ones of Groups 2 and 3. For each dowel space diameter, root canals obturated using CB of Groups 3 and 5 showed significantly higher dowel retention compared to those obturated using EB of Groups 2 and 4. Post retention to the over-prepared dowel spaces of Groups 4 and 5 was significantly higher than that recorded for the optimally-prepared ones of Groups 1-3. SEM images revealed traces of endodontic sealer and gutta-percha on the walls of the optimally-prepared dowel spaces. CONCLUSION: Despite the adverse effect of endodontic sealers on the retention of fiber posts, the over-preparation of dowel spaces helps to improve the retention.

Alum Directly Modulates Murine B Lymphocytes to Produce IgG1 Isotype

Aluminum hydroxide (alum) is the most widely used adjuvant in human vaccines. Nevertheless, it is virtually unknown whether alum acts on B cells. In the present study, we explored the direct effect of alum on Ig expression by murine B cells in vitro. LPS-activated mouse spleen B cells were cultured with alum, and the level of isotype-specific Ig secretion, IgG1 secreting cell numbers, and Ig germ-line transcripts (GLT) were measured using ELISA, ELISPOT, and RT-PCR, respectively. Alum consistently enhanced total IgG1 production, numbers of IgG1 secreting cells, and GLTgamma1 expression. These results demonstrate that alum can directly cause IgG1 isotype switching leading to IgG1 production.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide

OBJECTIVES: The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. MATERIALS AND METHODS: A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. RESULTS: All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. CONCLUSIONS: This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.

Estudo comparativo entre o teste do pH e do KOH versus escore de Nugent para diagnóstico da vaginose bacteriana em gestantes / Comparative study between the pH test and of the KOH versus Nugent score for diagnosis of bacterial vaginosis in pregnant women

OBJETIVO: Aquilatar a prevalência da vaginose bacteriana e comparar a acurácia dos testes do pH e do KOH com o gradiente de Nugent, método padrão-ouro, no diagnóstico da vaginose bacteriana (VB) em gestantes assintomáticas e sintomáticas de baixo risco. MÉTODOS: Foi realizado um estudo de corte transversal em 321 grávidas, com idade gestacional entre 14ª e 26ª semanas, 218 assintomáticas e 103 com queixa de secreção vaginal sugestiva de vaginose bacteriana. Todas as gestantes foram avaliadas pelos critérios de Nugent e submetidas à pHmetria vaginal e ao teste do KOH a 10%. O coeficiente de Kappa foi utilizado para avaliar os métodos quanto à concordância diagnóstica. RESULTADO: A maioria das gestantes era adolescente (média etária 21,0±5,6 anos), nulípara e parda. A prevalência da vaginose bacteriana foi de 33,3% pelo método de pH e KOH e de 35,5% pelo Nugent. Entre as grávidas assintomáticas, foi observada ótima concordância dos métodos, com 72,5% delas apresentando resultados negativos para ambos os métodos, o que resultou em um elevado coeficiente de Kappa (k=0,82). No grupo de gestantes sintomáticas, houve 49,5% de positividade para ambos os métodos diagnósticos, demonstrando ótima concordância (k=0,74). CONCLUSÃO: A prevalência da vaginose bacteriana foi elevada tanto pelo método de pH e KOH quanto pelo Nugent. O método do pH e KOH é tão capaz em diagnosticar a vaginose bacteriana quanto os critérios de Nugent.

PURPOSE: To assess the prevalence of bacterial vaginosis and to compare the accuracy of testing pH and KOH with the Nugent gradient, the gold standard for the diagnosis of bacterial vaginosis (BV) in asymptomatic and symptomatic pregnant women at low risk. METHODS: We conducted a cross-sectional study on 321 pregnant women with gestational age between 14 and 26 weeks, 218 of them asymptomatic and 103 with vaginal complaints suggestive of bacterial vaginosis. All women were assessed by the criteria of Nugent and subjected to the measurement of vaginal pH and to the 10% KOH test. The Kappa coefficient was used to evaluate the methods in terms of diagnostic agreement. RESULTS: Most patients were adolescents (mean age 21.0±5.6 years), nulliparous and mulattos. The prevalence of bacterial vaginosis was 33.3% as estimated by the pH and KOH method and 35.5% by the Nugent method. Excellent agreement of the methods was found among asymptomatic pregnant women, with 72.5% of them showing negative results to both tests, which resulted in a high Kappa coefficient (k=0.82). The group of symptomatic women showed 49.5% positivity to both diagnostic methods, with excellent agreement (k=0.74). CONCLUSION: The prevalence of bacterial vaginosis determined by both the pH and KOH method and the Nugent score was high. The pH and KOH method can diagnose bacterial vaginosis as accurately as the Nugent criterion.

Analysis of Methylmercury Concentration in the Blood of Koreans by Using Cold Vapor Atomic Fluorescence Spectrophotometry

BACKGROUND: Methylmercury is an organic form of mercury that is highly toxic to humans. Here, we present and establish a novel method to detect methylmercury concentrations in the blood of Koreans. METHODS: Methylmercury concentration was analyzed with an automated methylmercury analytic system (MERX, Brooks Rand Co., USA) using cold vapor atomic fluorescence spectrophotometry (CVAFS). A variety of biological materials were digested in methanolic potassium hydroxide solution. The analysis method was validated by examination of certified reference material (955c, National Institute of Standard and Technology, USA). We randomly selected 30 Korean adults (age 20 yr or older) to analyze total blood mercury and methylmercury concentrations. RESULTS: The detection limit and methylmercury recovery rate using this method were 0.1 pg/L and, 99.19% (range: 89.33-104.89%), respectively. The mean blood concentration of methylmercury was 4.54+/-2.15 microg/L (N=30). The mean proportion of methylmercury to the total mercury concentration was 78.27% (range: 41.37-98.80%). CONCLUSIONS: This study is the first report to analyze blood methylmercury concentration using CVAFS in Korea. We expect that this method will contribute to the evaluation of mercury exposure and the assessment of the toxicological impact of mercury in future studies.

Fingernail Onychomycosis Due to Aspergillus niger

Onychomycosis is usually caused by dermatophytes, but some species of nondermatophytic molds and yeasts are also associated with nail invasion. Aspergillus niger is a nondermatophytic mold which exists as an opportunistic filamentous fungus in all environments. Here, we report a case of onychomycosis caused by A. niger in a 66-year-old female. The patient presented with a black discoloration and a milky white base and onycholysis on the proximal portion of the right thumb nail. Direct microscopic examination of scrapings after potassium hydroxide (KOH) preparation revealed dichotomous septate hyphae. Repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide produced the same black velvety colonies. No colony growth occurred on SDA with cycloheximide slants. Biseriate phialides covering the entire vesicle with radiate conidial heads were observed on the slide culture. The DNA sequence of the internal transcribed spacer region of the clinical sample was a 100% match to that of A. niger strain ATCC 16888 (GenBank accession number AY373852). A. niger was confirmed by KOH mount, colony identification, light microscopic morphology, and DNA sequence analysis. The patient was treated orally with 250 mg terbinafine daily and topical amorolfine 5% nail lacquer for 3 months. As a result, the patient was completely cured clinically and mycologically.

Onychomycosis Caused by Scopulariopsis brevicaulis: Report of Two Cases

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. Scopulariopsis brevicaulis is a nondermatophytic mold found in soil as a saprophyte. We report two cases of onychomycosis caused by S. brevicaulis in a 48-year-old male and a 79-year-old female. The two patients presented with a typical distal and lateral subungual onychomycosis. Direct microscopic examination of the potassium hydroxide preparation revealed fungal elements. From toenail lesions of the patients, brown colonies with powdery surface, which are a characteristic of S. brevicaulis, were cultured on two Sabouraud's dextrose agar plates. Three cultures taken from nail plates within a 2-week interval yielded similar findings. Numerous branched conidiophores with chains of rough walled, lemon-shaped conidia were observed in slide culture by light microscopy and scanning electron microscopy. The nucleotide sequences of the internal transcribed spacer for the two clinical isolates were identical to that of S. brevicaulis strain WM 04.498. To date, a total of 13 cases of S. brevicaulis onychomycosis including the two present cases have been reported in Korea. Mean age of the patients was 46.1 years, with a higher prevalence in males (69.2%). Toenail involvement was observed in all cases including a case involving both fingernail and toenail. The most frequent clinical presentation was distal and lateral subungual onychomycosis in 12 cases, while one case was proximal subungual onychomycosis.