Increased expression of keratinase and other peptidases by Candida parapsilosis mutants

Keratinases are enzymes of great importance involved in pathogenic processes of some fungi. They also have a widespread ecological role since they are responsible for the degradation and recycling of keratin. On the one hand, studying them furthers our knowledge of pathogenicity mechanisms, which has important implications for human health, and on the other hand, understanding their ecological role in keratin recycling has biotechnological potential. Here, a wild-type keratinolytic Candida parapsilosis strain isolated from a poultry farm was treated with ethyl methanesulfonate in order to generate mutants with increased keratinase activity. Mutants were then cultured on media with keratin extracted from chicken feathers as the sole source of nitrogen and carbon. Approximately 500 mutants were screened and compared with the described keratinolytic wild type. Three strains, H36, I7 and J5, showed enhanced keratinase activity. The wild-type strain produced 80 U/mL of keratinolytic activity, strain H36 produced 110 U/mL, strain I7, 130 U/mL, and strain J5, 140 U/mL. A 70 percent increase in enzyme activity was recorded for strain J5. Enzymatic activity was evaluated by zymograms with proteic substrates. A peptidase migrating at 100 kDa was detected with keratin, bovine serum albumin and casein. In addition, a peptidase with a molecular mass of 50 kDa was observed with casein in the wild-type strain and in mutants H36 and J5. Gelatinase activity was detected at 60 kDa. A single band of 35 kDa was found in wild-type C. parapsilosis and in mutants with hemoglobin substrate.

Antinociceptive properties of the essential oil of Ocimum gratissimum L. (Labiatae) in mice

We have investigated the antinociceptive effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) in two classical models of pain in male Swiss mice (25-35 g), the writhing test and the formalin test. At doses of 30, 100 and 300 mg/kg (po), EOOG produced a dose-dependent inhibition (from 58.3 ± 4.4 to 40.7 ± 6.3, 36.4 ± 3.6 and 24.6 ± 3.6, respectively; N = 8-10, P<0.05) of acetic acid-induced writhing, causing up to a 60 percent inhibition at the highest dose used, comparable to that obtained with indomethacin (10 mg/kg, po). At the same doses, EOOG predominantly inhibited the late (inflammatory) phase of the formalin-induced pain response (from 59.3 ± 8.3 to 40.4 ± 4.8, 23.2 ± 2.8 and 25.3 ± 5.5, respectively; N = 6, P<0.05), with a maximal reduction of 60 percent of the control, although a significant reduction of the initial (neurogenic) phase was also observed at 300 mg/kg (from 62.5 ± 6.07 to 37 ± 5.9; P<0.05). On the basis of these data, we conclude that EOOG possesses interesting antinociceptive properties in the writhing and formalin tests. Due to the relatively low toxicity of EOOG, further detailed examination is strongly indicated for a better characterization of its pharmacological properties and its potential therapeutic value

Kinetic mechanism of the inhibition of human urinary kallikrein by basic pancreatic trypsin inhibitor

Hydrolysis of D-valvyl-L-leucyl-L-arginine p-nitroanilide (D-Val-Leu-Arg-Nan) at five different concentration (10-20µM) by human urinary kallikrein was studied in the absence and in the presence of increasing concentrations of basic pancreatic trypsin inhibitor (BPTI) (1.35-9.15nM). The data indicate that the inhbition of human urinary kallikrein by BPTI is not a simple competitive inhibition as reported by others, but that it is a competitive inhibition of the parabolic type, with two inhibitor molecules binding to one enzyme molecule, with the formetion of a ternary enzymatic complex. Statistical analysis of the experimental data supports the kinetic model proposed. The calculated values of the constants Ki and Kii were 16.20 nM and 1.10 nM, repectively. It is noteworthy that the Kii < Ki, i.e., the second BPTI molecule binds to the enzyme with a larger affinity suggesting that this second binding site was probably created or positively modulated as a consequence of the binding of the first BPTI molecule

Variacao dos niveis do componente C3 do complemento em Holochilus brasiliensis nanus experimentalmente infectados com Schistosoma mansoni. / Changes in the component C3 levels in Holochilus brasiliensis nanus experimentally infected with Schistosoma mansoni

As variacoes dos niveis do componente C3 do complemento foram verificadas em soros de exemplares do roedor silvestre Holochilus brasiliensis nanus infectados experimentalmente com Schistosoma mansoni, aplicando-se a tecnica de imunoeletroforese bidimensional quantitativa. Foram utilizados soros de animais normais, da mesma especie e idade, como controle da experiencia. A quantificacao foi feita durante oito semanas, contadas a partir da data da infeccao. O perfil serico mostrou que o nivel inicial do C3 foi duas vezes menor que o observado no grupo controle. Este nivel permaneceu ate a 6a. semana de observacao. A partir desta semana ate a oitava foram registrados niveis aproximadamente 3 a 4 vezes menores que os observados no grupo controle

Fatores relacionados com o planejamento familiar em populacoes de baixa renda de Porto Alegre. / Factors related to family planning in low income populations of Porto Alegre

O presente trabalho faz um levantamento do planejamento familiar em populacoes de baixa renda de Porto Alegre, relacionando com variaveis economico-culturais. Verificou-se uma prevalencia de 78%, sendo os ACO preferentemente utilizados. A motivacao dominante a planificacao familiar foi a dificuldade economica para sustentar uma nova crianca

Ocorrencia de linhagens humana e silvestre de Schistosoma mansoni, na pre-amazonia. I - Estudo em moluscos. / Occurrence of wild and human strains of Schistosoma mansoni in pre Amazonia.I - Study in moluscs

Foram isoladas na regiao da Baixada Maranhense (Brasil), linhagens humana(H) e silvestre(S) de Schistosoma mansoni a partir de miracidios eclodidos de ovos encontrados em fezes de doentes humanos autoctones da Regiao e de figados de roedores silvestres naturalmente infectados.Biomphalaria glabrata, descendentes de caramujos coletados no campo foram expostos, isoladamente, aos miracidios H e S, mantidos isolados em moluscario e observados durante 100 dias. Moluscos normais foram mantidos nas mesmas condicoes de ambiente em que foram submetidos os infectados e tomados como controle da experiencia. Foram anotados os indices de infeccao dos moluscos, as datas da eliminacao de cercarias, quantidade de larvas eliminadas e mortalidade dos moluscos. Os dados sugeriram melhor adaptacao do esquistossomo da linhagem H e B. glabrata. A linhagem S, por sua vez, foi tres vezes mais virulenta do que a linhagem H. Estes dados foram comparados com os encontrados na literatura especializada e verificado diversidades nos comportamentos parasitologicos das linhagens em estudo, quando comparados com os encontrados nas linhagens H e S oriundas do Vale do Rio Paraiba do Sul, no Estado de Sao Paulo (Brasil).(Brasil)