Avaliação da granulometria de fosfatos utilizados em ração para frangos tipo caipira

Foram utilizados 200 frangos de corte da linhagem “Pesadão”, distribuídos em delineamento inteiramente casualizado, em esquema fatorial 2 x 2, sendo dois fosfatos (Fosfato bicálcico e Fosfato monobicálcico) e duas granulometrias (Pó e Microgranulado), com cinco repetições, com dez aves por unidade experimental. As aves foram submetidas aos seguintes tratamentos: FBP: ração basal com fosfato bicálcico pó; FBM: ração basal com fosfato bicálcico microgranulado; MBP: ração basal com fosfato monobicálcico pó; e MBM: ração basal com fosfato monobicálcico microgranulado. Foram avaliados os parâmetros de desempenho das aves no período de 23 a 38 dias de idade. Para avaliação da composição química e da granulometria das rações restantes nos pratos dos comedouros, foram feitas coletas diariamente, sendo que essas amostras foram agrupadas em três períodos: do dia 23 ao 28; do dia 29 ao 33; e do dia 34 aos 38 dias de idade. Não houve interação entre as fontes e as granulometrias dos fosfatos em todos os parâmetros de desempenho. Houve interação entre fontes e granulometria dos fosfatos nos parâmetros de proteína bruta (PB), no período de 23 a 28 dias de idade, no qual a concentração de PB foi maior nos comedouros dos tratamentos contendo MBM e maiores valores de fósforo (P), cálcio (Ca), ferro (Fe) e partículas médias na ração dos comedouros contendo fosfatos microgranulados (FM). Nos períodos de 29 a 38 dias de idade, foram observados menores valores de PB e maiores valores de P e Ca nas rações dos comedouros contendo FM, bem como maiores valores de Fe no período de 34 a 38 dias. Neste último período, também se observou aumento no módulo de finura, aumento no diâmetro geométrico médio e maiores valores de partículas médias para FBM, mas para partículas finas os maiores valores foram para FBP. Concluiu-se que as fontes e granulometrias dos fosfatos da ração não afetam o desempenho dos frangos tipo “Caipira”. Entretanto, a utilização de fosfatos granulados pode promover a segregação das partículas dentro dos comedouros.

Avaliação do desempenho produtivo de matrizes suínas submetidas a diferentes números de inseminações pós-cervicais

Objetivou-se avaliar o desempenho produtivo de matrizes suínas submetidas à diferentes números de inseminações pós-cervicais. Foram utilizadas 600 matrizes de ordem de parto de 2a a 7a, sendo que 300 matrizes receberam três inseminações pós-cervicais e 300 receberam duas inseminações pós-cervicais. Para cada ordem de parto, foram empregadas 50 fêmeas. As médias de peso ao nascimento foram avaliadas pelo teste de Tukey e para os demais parâmetros foi feita a técnica de decomposição em valores singulares (DVS) das contagens obtidas. O comportamento da média de peso dos leitões foi similar para ambos os números de inseminações (duas ou três). Entretanto, os leitões nascidos de matrizes inseminadas duas vezes obtiveram peso médio ao nascimento superior aos leitões nascidos das matrizes inseminadas três vezes, principalmente até o quarto ciclo reprodutivo. De qualquer maneira, essa diferença não ocorreu nos ciclos reprodutivos finais (5, 6 e 7). Ao se utilizar duas inseminações, foi obtido o maior número de leitões nascidos vivos no terceiro ciclo; porém, o maior número de leitões natimortos foi identificado nos ciclos seis e sete. Ao se utilizar três inseminações, o maior número de leitões nascidos vivos ainda ocorre no ciclo três; porém o maior número de leitões natimortos ocorre a partir do ciclo quatro. Conclui-se que a utilização de duas inseminações é recomendada, visando a um maior peso dos leitões ao nascimento, sem causar prejuízos no número e viabilidade dos leitões. Consequentemente, tal procedimento permitiria obter menor custo de aplicação da biotécnica, além de proporcionar uma maior vida útil para a matriz suína.

Photodynamic Therapy in Veterinary Medicine: Applications in dogs and cats

The present article represents a critical review focused on the application of Photodynamic Therapy (PDT) in Veterinary Medicine. Presenting an especial highlight to pet area, this manuscript brings together interesting articles on the application of PDT in pets, especially dogs and cats. Evaluating relevant publications that denote the state-of-art of this area, this present work demonstrates the wide potential of PDT application in several veterinary diseases. In fact, this work presents advantages and disadvantages of PDT and the partially positive results that several important research groups have published. We believe that this work can be useful to researchers and clinical veterinary medicine, mainly those that worked mainly with small animals of the PET area. We believe that this work can be useful for researchers and clinical veterinarians, especially those who work mainly with small animals in the pet area.

Terapia Fotodinâmica: Conceitos básicos e aplicações veterinárias

Esse manuscrito apresenta os conceitos básicos da Terapia Fotodinâmica (TFD), descrevendo e analisando os componentes e etapas de sua ação fotodinâmica e sua potencialidade de eficácia terapêutica. É discutida a escolha de fotossensibilizadores (FS) e a fonte de energia eletromagnética, assim como os mecanismos TIPO I e TIPO II da ação fotodinâmica gerada pela excitação eletrônica do agente fotossensibilizante. Portanto, são analisados os aspectos químicos do estresse oxidativo gerado pelas espécies reativas de oxigênio (EROs) e espécies reativas de nitrogênio (ERNs), contemplando oxigênio singlete (1O2) e radicais livres. Por fim, comenta-se sobre as possibilidades de maior aplicação de TFD em medicina veterinária, sobretudo no que se refere aos animais de estimação.

Interaction between surfactants and proteins

Several approaches have been focused on the protein-surfactant interaction. Surfactant-protein interactions are very common in the fields of medicine, chemistry, biology etc. Indeed, many aspects of this interaction have been studied, such as the influence of the aggregation state of the surfactant (monomer, pre-micellar aggregate, micelle, and liposomes) on the protein structure, the properties of the surfactant-protein system, the characterization of the interaction sites on the protein surface, the identification of the intermediate protein conformations etc. The interaction of several types of proteins with the different kind of surfactant can furnish various information to the research of biochemical and biophysical systems, such as the structure-activity relationship of proteins as well as the mechanism of interaction between proteins and amphiphilic molecules. In this context, proteins with prosthetic group are very interesting ones, since the presence of the non-amino acid group can furnishes various information through different instrumental techniques of analysis, acting as a label of all polypeptide chains. The present work analyzes this topic and the potential of these studies.

Hemoglobina, auto oxidação, geração de radicais livres, lesão tecidual e estresse oxidativo: Interessante correlação associada aos acidentes vasculares

O presente manuscrito é focado sobre a relação entre hemoglobina, auto oxidação, geração de radicais livres (com especial ênfase em espécies reativas de oxigênio (EROs) e espécies reativas de nitrogênio (ERNs)), e os processos bioquímicos e fisiológicos que ocorrem em algumas situações biológicas e patológicas, principalmente acidentes vasculares, tais como acidente vascular encefálico (“derrame”) e infarto do miocárdio (infarto do coração). De fato, os diversos tipos de radicais livres são completamente associados aos processos químicos dos acidentes circulatórios assim como as subsequentes lesões nos tecidos biológicos. Interessantemente, os acidentes circulatórios hemorrágico e isquêmico das doenças vasculares estão relacionadas à presença de diversas espécies de radicais livres. Este trabalho apresenta várias correlações entre estes agentes químicos e bioquímicos, favorecendo compreender o importante papel dos radicais livres neste tipo de doença. É também sugerido que a análise dessas espécies químicas poderia constituir uma estratégia para avaliar a evolução da doença circulatória.

Heme Acquisition by trypanosomatids: Evaluation of the hemedependent behavior and its biochemical implications

The inability of some species to produce porphyrin-like compounds induces these species to search for blood to fulfill their heme requirement. The biological cycle of very relevant parasites, such as Leishmania sp. and Trypanossoma sp., is directly related to the search for heme. The understanding of this process in a chemical and biochemical approach is a pre-requisite to obtaining advancements regarding hemoprotein structureactivity relationships as well as molecular aspects of various pathological/physiological mechanisms associated with parasitary and/or blood diseases, between others. The present work presents an overview of the chemical/biochemical properties of porphyrin, heme, heme proteins, and parasitary diseases caused by Trypanossomatidae. We believe that this kind of discussion can contribute significantly to improve the understanding of the structure-function relation of these complex diseases

Digoxin reduces the mutagenic effects of Mitomycin C in human and rodent cell lines

Digoxin is a drug widely used to treat heart failure and studies have demonstrated its potential as anticancer agent. In addition, digoxin presents the potential to interact with a series of other compounds used in medicine. The aim of the present study was to evaluate in vitro the cytotoxicity, genotoxicity and mutagenicity of digoxin and its potential to interact with the mutagen Mitomycin C (MMC). The cytotoxicity of digoxin was assessed by employing the MTT method and the comet assay was performed to assess the genotoxicity of this medicine in CHO-K1 and HeLa cell lines. Besides, the cytokinesis-block micronucleus assay was performed to assess the mutagenicity and the antimutagenicity of this drug. The Ames assay was also performed with TA98 and TA100 strains of S. typhimurium. Results showed that digoxin was cytotoxic, genotoxic and mutagenic for HeLa and CHO-K1 cell lines at concentrations many times higher than those observed in human therapeutic conditions. Nevertheless, an antimutagenic effect against the mutagen MMC was observed on both cell lines in concentrations near those used therapeutically in humans. This chemoprotective effect observed is an interesting finding that should be better explored regarding its impact in anticancer chemotherapy.

Synergism between fluconazole and methylene blue-photodynamic therapy against fluconazole-resistant Candida strains

Photodynamic therapy (PDT) has been proved to be effective against fungi and it may be employed as a coadjutant to conventional antifungal agents, leading to a more effective microbial control minimising side effects. This work evaluates the combined effect of PDT and fluconazole against resistant Candida albicans, Candida glabrata and Candida krusei. The yeasts were submitted to methylene blue-PDT (MB-PDT) in sub-inhibitory concentrations. In the present work, MB-PDT combined with fluconazole was more efficient in the inhibition of the C. albicans and C. glabrata than each treatment alone, being possible to infer that the treatments are synergic.

In vitro photodynamic therapy against Foncecaea pedrosoi and Cladophialophora carrionii

Photodynamic therapy (PDT) has been originally developed for cancer treatment, but recently, it has been successfully employed against microorganisms, including fungi. Chromoblastomycosis is a subcutaneous fungal infection that is recalcitrant to conventional antifungal drug therapy. The most frequent species involved are Foncecaea pedrosoi and Cladophialophora carrionii. The present study aimed to verify the efficacy in vitro of PDT employing methylene blue (MB) as a photosensitiser and Light emmiting diode (LED) (InGaAl) as the light source. Methylene blue at the concentrations of 16, 32 and 64 μg/mL and LED (InGalP) were employed for 15 min against spores of two isolates of F. pedrosoi and two isolates of C. carrionii. The spores were plated on Sabouraud Dextrose agar and the number of colony forming units was counted after 7-10 days of incubation at 37 °C. The PDT with MB and LED was efficient in reducing the growth of all samples tested. Better results were obtained for the concentration of 32 μg/mL of MB. The treatment proved to be highly effective in killing the samples of F. pedrosoi and Cladophialophora pedrosoi tested in vitro. PDT arises as a promising alternative for the treatment of this subcutaneous infection.

Ligand changes in ferric species of the giant extracellular hemoglobin ofGlossoscolex paulistusas function of pH: correlations between redox, spectroscopic and oligomeric properties and general implications with different hemoproteins

The present review is focused on the relationship between oligomeric and heme properties of HbGp, emphasizing the characteristics that can be generalized to other hemoproteins. This study represents the state-of-the-art with respect to the approaches for investigating giant extracellular hemoglobins as well as the correlation between oligomeric assembly alterations and their consequent changes in the first coordination sphere. A wide introduction focused on the properties of this hemoglobin is developed. Indeed, this hemoprotein is considered an interesting prototype of blood substitute and biosensor due to its peculiar properties, such as resistance to autoxidation and oligomeric stability. Previous studies by our group employing UV-vis, EPR and CD spectroscopies have been revised in a complete approach, in agreement with recent and relevant data from the literature. In fact, a consistent and inter-related spectroscopic study is described propitiating a wide assignment of "fingerprint" peaks found in the techniques evaluated in this paper. This review furnishes physicochemical information regarding the identification of ferric heme species of hemoproteins and metallic complexes through their spectroscopic bands. This effort at the attribution of UV-vis, EPR and CD peaks is not restricted to HbGp, and includes a comparative analysis of several hemoproteins involving relevant implications regarding several types of iron-porphyrin systems.

Antifungal suscepitibility profile of candida spp. oral isolates obtained from denture wearers

Denture stomatitis is an inflammatory condition that occurs in denture wearers and is frequently associated with Candida yeasts. Antifungal susceptibility profiles have been extensively evaluated for candidiasis patients or immunosupressed individuals, but not for healthy Candida carriers. In the present study, fluconazole, itraconazole, voriconazole, terbinafine and 5-flucytosin were tested against 109 oral Candida spp. isolates. All antifungal agents were effective against the samples tested except for terbinafine. This work might provide epidemiological information about Candida spp. drug susceptibility in oral healthy individuals.

In vitro antifungal susceptibility of clinical isolates of Candida spp. obtained from patients with different predisposing factors to candidosis

The increase in the number of infections caused by Candida species and the consequent use of antifungal agents favours an increase of resistant isolates. The aim of this study was to evaluate the antifungal susceptibility of Candida spp. isolates from patients with different systemic predisposing factors to candidosis. Seventy-nine Candida spp. isolates were assayed for in vitro susceptibility to amphotericin B, fluconazole, 5-flucytosine and itraconazole using the technique proposed by the Clinical and Laboratory Standards Institute (CLSI). Four C. albicans, one C. guilliermondii, four C. parapsilosis and two C. tropicalis isolates were resistant to amphotericin B. Only two isolate was resistant to itraconazole. All the isolates tested were susceptible to fluconazole and flucytosine. It could be concluded that the most efficient drugs against the Candida isolates studied were fluconazole and flucytosine and that all of the antifungal agents used in this study were effective against the Candida spp. isolates tested.

Low level laser therapy (LLLT) decreases pulmonary microvascular leakage, neutrophil influx and IL-1beta levels in airway and lung from rat subjected to LPS-induced inflammation

BACKGROUND AND OBJECTIVE

Low level laser therapy (LLLT) is a known anti-inflammatory therapy. Herein we studied the effect of LLLT on lung permeability and the IL-1beta level in LPS-induced pulmonary inflammation. STUDY DESIGN/METHODOLOGY: Rats were divided into 12 groups (n = 7 for each group). Lung permeability was measured by quantifying extravasated albumin concentration in lung homogenate, inflammatory cells influx was determined by myeloperoxidase activity, IL-1beta in BAL was determined by ELISA and IL-1beta mRNA expression in trachea was evaluated by RT-PCR. The rats were irradiated on the skin over the upper bronchus at the site of tracheotomy after LPS.

RESULTS

LLLT attenuated lung permeability. In addition, there was reduced neutrophil influx, myeloperoxidase activity and both IL-1beta in BAL and IL-1beta mRNA expression in trachea obtained from animals subjected to LPS-induced inflammation.

CONCLUSION

LLLT reduced the lung permeability by a mechanism in which the IL-1beta seems to have an important role.

Correlation between CLSI, EUCAST and Etest methodologies for amphotericin B and fluconazole antifungal susceptibility testing of Candida spp. clinical isolates

This study analyzed the correlation between the results obtained through two microdilution methods: Clinical and Laboratory Standard Institute (CLSI) (M27-A2) and European Committee on Antibiotic Susceptibility Testing (EUCAST) (document E. Dis. 7.1) and an agar base method Etest for determining minimmun inhibitory concentration (MIC) for amphotericin B and fluconazole against 30 clinical isolates of Candida spp. The agreement between Etest, CLSI and EUCAST MICs within +/- 2 log2 dilutions was higher for amphotericin B than for fluconazole However, Pearson correlation demonstrated a greater agreement for fluconazole. The categorical agreement between MICs provided by the Etest/ CLSI and Etest/EUCAST methodologies was high for both amphotericin B (100%) and fluconazole (> or = 96.66%). This study demonstrated the adequacy of Etest method using Mueller Hinton agar to evaluate amphotericin B and fluconazole susceptibility of clinical isolates of Candida spp.

Serotype and mating type characterization of Cryptococcus neoformans by multiplex PCR

Cryptococcus neoformans is an encapsulated yeast, etiological agent of cryptococcosis. The species is commonly associated with pigeon droppings and plant materials. The aim of the present work was to verify the presence of the yeast in pigeon droppings, and to identify the isolates obtained in serotypes and mating types (MAT). Ten samples of pigeon droppings were collected in the rural area of the city of Alfenas, Brazil. Samples were inoculated in agar Niger medium for fungal isolation and 22 isolates with characteristics of C. neoformans were obtained. The serotypes and MAT were determined by multiplex PCR using specific primers. Serotypes were also determined by using the Kit Crypto Check. Among the 22 samples evaluated, eight were identified as C. neoformans by classic identification tests. These samples were characterized as serotype A by the Kit Crypto check and as serotype A MAT alpha by the multiplex PCR. The present study reinforces the evidence that pigeon droppings are a reservoir for C. neoformans and confirms the prevalence of C. neoformans var. grubii (A alpha) among environmental isolates. It also demonstrates that multiplex PCR is an acceptable alternative for serotype analysis because it reduces the costs for each reaction and analyses serotype and MAT simultaneously.

Comparison between E-test and CLSI broth microdilution method for antifungal susceptibility testing of Candida albicans oral isolates

Thirty Candida albicans isolated from oral candidosis patients and 30 C. albicans isolated from control individuals were studied. In vitro susceptibility tests were performed for amphotericin B, fluconazole, 5-flucytosine and itraconazole through the Clinical and Laboratorial Standards Institute (CLSI) reference method and E test system. The results obtained were analyzed and compared. MIC values were similar for the strains isolated from oral candidosis patients and control individuals. The agreement rate for the two methods was 66.67% for amphotericin B, 53.33% for fluconazole, 65% for flucytosine and 45% for itraconazole. According to our data, E test method could be an alternative to trial routine susceptibility testing due to its simplicity. However, it can not be considered a substitute for the CLSI reference method.

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

The present work is focussed on the principles of photodynamic therapy (PDT), emphasizing the photochemical mechanisms of reactive oxygen species formation and the consequent biochemical processes generated by the action of reactive oxygen species on various biological macromolecules and organelles. This paper also presents some of the most used photosensitizers, including Photofrin, and the new prototypes of photosensitizers, analysing their physicochemical and spectroscopic properties. At this point, the review discusses the therapeutic window of absorption of specific wavelengths involving first- and second-generation photosensitizers, as well as the principal light sources used in PDT. Additionally, the aggregation process, which consists in a phenomenon common to several photosensitizers, is studied. J-aggregates and H-aggregates are discussed, along with their spectroscopic effects. Most photosensitizers have a significant hydrophobic character; thus, the study of the types of aggregation in aqueous solvent is very relevant. Important aspects of the coordination chemistry of metalloporphyrins and metallophthalocyanines used as photosensitizers are also discussed. The state-of-the-art in PDT is evaluated, discussing recent articles in this area. Furthermore, macrocyclic photosensitizers, such as porphyrins and phthalocyanines, are specifically described. The present review is an important contribution, because PDT is one of the most auspicious advances in the therapy against cancer and other non-malignant diseases.

Antifungal activity of the amyrin derivatives and in vitro inhibition of Candida albicans adhesion to human epithelial cells

AIMS

The antifungal activity of amyrin pentacyclic triterpene and 15 synthetic derivatives was evaluated against Candida species. Additionally, inhibition of adhesion of Candida albicans to human epithelial cells in vitro was determined.

METHODS AND RESULTS

Esterification of alpha- and beta-amyrin with a variety of acyl chlorides produced a series of analogue derivatives. These substances were synthesized to evaluate the antifungal properties against Candida species. Among the 15 derivatives, alpha- and beta-amyrin formiate (2) and alpha- and beta-amyrin acetate (3) were the most active, inhibiting all the Candida species tested in concentrations that ranged from 30 to 250 microg ml(-1). alpha- and beta-amyrin formiate inhibited the adhesion ability of C. albicans to buccal epithelial cells (BEC) in 65.3%.

CONCLUSIONS

alpha- and beta-amyrin formiate and alpha- and beta-amyrin acetate derivatives exhibited potential antifungal activity against Candida spp. and amyrin formiate showed inhibition of the adhesion ability of C. albicans to buccal epithelial cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrated that two derivatives of amyrin pentacyclic triterpene exhibited significant antifungal activity against Candida species. Additionally, alpha- and beta-amyrin formiate was as effective as fluconazole in inhibiting the adhesion of C. albicans to buccal epithelial cells.

Isolation of Cryptococcus neoformans from hollows of living trees in the city of Alfenas, MG, Brazil

Cryptococcus neoformans is an encapsulated yeast, aetiological agent of cryptococcosis, commonly associated with pigeon droppings and plant materials. The species has also been associated with tree hollows. The aim of the present work was to verify the presence of the yeast in hollows of living trees and identify the isolates obtained in varieties and serotypes. Three samples were collected from 18 trees of five different species totalling 54 samples. Wood samples were collected by scraping the surface of the trunks and the inner face of the hollows. Samples were inoculated on to agar Niger medium for fungal isolation. The serotypes were determined by PCR using specific primers. Among the 54 samples evaluated, two were positive for the presence of C. n. var. neoformans (serotype A and MATalpha). The trees belonged to Caesalpinia peltophoroides and Anadenanthera peregrina species. The results of this study suggest that decayed wood obtained from hollows of C. peltophoroides and A. peregrina can be used as natural habitat for C. n. var. neoformans.

Evaluation of adhesion to buccal epithelial cells in Candida species obtained from denture wearers after exposure to fluconazole

The aim of this study was to assess the adhesion ability by Candida spp. obtained from denture wearer patients with and without denture stomatitis and the possible reduction in adhesion after exposure to fluconazole. Nine C. tropicalis, five C. glabrata and two C. parapsilosis obtained from the oral cavity of patients with denture stomatitis and 11 C. tropicalis, nine C. glabrata and six C. parapsilosis obtained from the oral cavity of denture wearers with normal palatal mucosa were compared for adhesion ability to buccal epithelial cells (BEC) and reduction in adhesion after exposure to fluconazole. Candida spp. obtained from denture stomatitis patients were more adherent to BEC, and there was a reduction in adhesion after exposure to fluconazole in all the species tested. Our results demonstrated that exposure to fluconazole reduces Candida spp. adherence to BEC. These results also suggest that adhesion, even in non-albicans species, could be factors that, along with predisposing conditions related to the host, determine if an individual will develop disease or remain as a healthy carrier and confirm that fluconazole has an impact in the adherence ability in Candida spp.

Prevalence and antifungal susceptibility of yeasts obtained from the oral cavity of elderly individuals

Infections caused by Candida yeasts are common in elderly individuals. Seventy-five isolates of Candida spp. were obtained from saliva samples of 136 institutionalized elderly individuals resident in six retirement homes of Belo Horizonte, Brazil. Forty-seven isolates (62.66%) were identified as Candida albicans, 15 (20%) as C. tropicalis, 7 (9.33%) as C. glabrata, 4 (5.33) as C. parapsilosis, and 2 (2.67%) as C. guilliermondii. Among the 136 elderly individuals studied, 49 (36%) were male and 87 (64%) were female. Ages ranged from 60 to 90 years old. Sixty-three (46.3%) of the institutionalized individuals were denture wearers and, among them, 53 (84.1%) carried Candida yeasts in the oral cavity. Forty-four subjects presented lesions in the oral mucosa and among these, 36 (82%), had positive culture for Candida spp. The samples were tested for the in vitro susceptibility to amphotericin B, itraconazole, fluconazole and 5-flucytosin, and great variations were observed in the minimum inhibitory concentrations (MIC) of these drugs according to the species.

Virulence factors and antifungal susceptibility of Candida albicans isolates from oral candidosis patients and control individuals

Sixty isolates of Candida albicans, 30 obtained from the oral cavity of denture wearers presenting signs of candidosis and 30 obtained from the oral cavity of denture wearers with normal palatal mucosa were assayed for phospholipase and proteinase production, as well as for adherence to buccal epithelial cells. Likewise, susceptibility of the isolates to antifungals was determined by the NCCLS reference method and the E-test method. Proteinase activity was increased among the strains obtained from oral candidosis patients. In contrast, no significant differences between the two groups of isolates were observed in their adherence ability in vitro, in phospholipase production, and susceptibility to antifungal drugs.

Predisposing conditions forCandidaspp. carriage in the oral cavity of denture wearers and individuals with natural teeth

Candida species are a normal commensal present in a large percentage of healthy individuals. Denture wearers are predisposed to the development of candidosis and to the presence of Candida spp. The presence of the yeast, even in healthy subjects, should be considered more carefully. We investigated the prevalence of Candida spp. in 112 denture wearers and 103 individuals with natural teeth, patients from the clinic of total prosthesis of the Dental School of the Federal University of Minas Gerais, Brazil, and from the School of Pharmacy and Dentistry of Alfenas, Brazil. Factors like gender, age over 60 years, low education, and xerostomia were directly associated with the presence of Candida yeasts at a significance level of 5% (p > 0.05). However, the major predisposing factor for the carrier state was wearing dentures (p = 0.001). Candida isolates were identified using morphological and biochemical profiles. Seventy-one isolates were identified as C. albicans (65.1%), 15 as C. glabrata (13.7%), 8 as C. parapsilosis (7.3%), 3 as C. krusei (2.7%), and 12 as C. tropicalis (11.0%). Susceptibility testing to fluconazole and itraconazole was also performed with the strains obtained. Both drugs showed a strong inhibition against most oral isolates.Key words: yeast infection, prosthetic devices, oral cavity.

Developmental toxicity evaluation of inhaled toluene diisocyanate vapor in CD rats

Mated female CD (Sprague-Dawley) rats, 25/group, were exposed to toluene diisocyanate (TDI) vapor, for six h/day on gestational days (gd) 6 through 15, at 0.00, 0.02, 0.10, or 0.50 p.p.m.. Maternal clinical signs, body weights, and feed and water consumption were recorded throughout gestation. At termination (gd 21), maternal body, gravid uterine, and liver weights were recorded. Corpora lutea were counted, and implantation sites were identified: resorptions and dead and live fetuses. All live fetuses were examined for external alterations. One-half of the live fetuses/litter were examined for visceral (including craniofacial) alterations. The remaining intact fetuses/litter were stained with alizarin red S and examined for ossified skeletal alterations. Maternal toxicity at 0.50 ppm consisted of reduced body weights, body weight gains, feed consumption, and clinical signs of toxicity. Water consumption was unaffected. Gestational parameters exhibited no significant treatment-related changes, including pre- and postimplantation loss, sex ratio/litter, or fetal body weights/litter. Incidences of individual malformations, malformations by category (external, visceral, and skeletal), total malformations, individual external and visceral variations, variations by category, and total variations were unaffected. Of 111 skeletal variants observed, only 1, incidence of poorly ossified cervical centrum 5, was increased at 0.50 ppm, indicating possible minimal fetotoxicity, although it occurred in the absence of any other indications of developmental toxicity. Therefore, exposure to TDI vapor by inhalation, during major organogenesis in CD rats, resulted in maternal toxicity and minimal fetotoxicity at 0.50 ppm no observed adverse effect level (NOAEL) for maternal and developmental toxicity was 0.10 ppm. No treatment-related embryotoxicity or teratogenicity was observed.

Two-generation reproductive toxicity study of inhaled toluene diisocyanate vapor in CD rats

Twenty-eight 42-day-old pups/sex/group (F0) were exposed to toluene diisocyanate vapor (TDI; 80% 2,4-TDI, 20% 2,6-TDI) by inhalation at 0.0, 0.02, 0.08, or 0.3 ppm, 6 h/day, 5 days/week, for 10 weeks, then mated within groups for 3 weeks, with exposure 7 days/week during mating, gestation, and lactation. F0 maternal animals were not exposed from gestational day (gd) 20 through postnatal day (pnd) 4; maternal exposures resumed on pnd 5. Twenty-eight weanlings/sex/group continued exposure for 12 weeks (starting on pnd 28) and were bred as described above. F0 and F1 parents and ten F1 and F2 weanlings/sex/group were necropsied, and adult reproductive organs, pituitary, liver, kidneys, and upper respiratory tract (target organs) were evaluated histologically in ten/sex/group. Adult toxicity was observed in both sexes and generations at 0.08 and 0.3 ppm, including occasional reductions in body weights and weight gain, clinical signs of toxicity at 0.08 and 0.3 ppm, and histologic changes in the nasal cavities at 0.02, 0.08, and 0.3 ppm (including rhinitis, a nonspecific response to an irritating vapor, at all concentrations). There was no reproductive toxicity, reproductive organ pathology, or effect on gestation or lactation at any exposure concentration. Postnatal toxicity and reduced body weights and weight gains during lactation occurred only in F2 litters at 0.08 and 0.3 ppm. Therefore, under the conditions of this study, a no observed adverse effect level (NOAEL) was not determined for adult toxicity; the NOAEL for reproductive toxicity was at least 0.3 ppm, and the NOAEL for postnatal toxicity was 0.02 ppm.

Reproduction and fertility evaluations in CD rats following nitrobenzene inhalation

A two-generation reproduction study was performed by exposure of Sprague-Dawley CD rats to concentrations of 40, 10, 1, or 0 (control) ppm of nitrobenzene (NB) vapor. No NB-related effects on reproduction were observed at 10 or 1 ppm. At 40 ppm, a decrease in the fertility index of the F0 and F1 generations occurred, which was associated with alterations in the male reproductive organs. Specifically, weights of testes and epididymides were reduced and seminiferous tubule atrophy, spermatocyte degeneration, and the presence of giant syncytial spermatocytes were observed. The only significant finding in the litters derived from rats exposed to 40 ppm was an approximate 12% decrease in the mean body weight of F1 pups on Postnatal Day 21. Survival indices were unaltered. To examine the reversibility of this selective effect on male gonads, the F1 males from the 40-ppm group were allowed a 9-week nonexposure period and mated to naive females. An almost fivefold increase in the fertility index was observed, indicating at least partial functional reversibility upon removal from NB exposure. Also, the numbers of giant syncytial spermatocytes and degenerated spermatocytes were greatly reduced. The results of this study support the selection of 10 ppm of NB as the no-observable-effect level for reproduction and fertility effects in rats.

Development toxicity evaluation of inhaled nitrobenzene in CD rats

Pregnant CD (Sprague-Dawley) rats were exposed to nitrobenzene vapor (CAS Registry No. 98-95-3) at 0, 1, 10, and 40 ppm (mean analytical values of 0.0, 1.06, 9.8, and 39.4 ppm, respectively) on gestational days (gd) 6 through 15 for 6 hr/day. At sacrifice on gd 21, fetuses were evaluated for external, visceral, and skeletal malformations and variations. Maternal toxicity was observed: weight gain was reduced during exposure (gd 6-9 and 6-15) to 40 ppm, with full recovery by gd 21, and absolute and relative spleen weights were increased at 10 and 40 ppm. There was no effect of treatment on maternal liver, kidney, or gravid uterine weights, on pre- or postimplantation loss including resorptions or dead fetuses, on sex ratio of live fetuses, or on fetal body weights (male, female, or total) per litter. There were also no treatment-related effects on the incidence of fetal malformations or variations. In summary, during organogenesis in CD rats, there was no developmental toxicity (including teratogenicity) associated with exposure to nitrobenzene concentrations that produced some maternal toxicity (10 and 40 ppm) or that produced no observable maternal toxicity (1 ppm).