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1.
Carbohydr Res ; 493: 108035, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32497942

RESUMO

Nanocrystalline chitosan (NCC) is a modified form of chitosan, prepared from the method for obtaining chitosan acetate (CA). Due to the greater crystallinity of chitosan nanoparticles in relation to CA, NCC is more thermally stable and thus has great potential in the development of a new generation of biomaterials potentially useful in regenerative medicine and tissue engineering. NCC is also characterized by having similar properties to its precursor chitosan, such as its biocompatibility, bioactivity, ability to be bioabsorbed and lack of toxicity. One of the major problems associated with obtaining NCC is the low productivity of the methods. While known methods of obtaining nanostructures produce small amounts (milligrams), the method of synthesis for creating NCC from its salt is often more productive and less costly, and is patented by the authors of this work (registration number: BR10201702272). Thus, the objective of this study was to characterize NCC obtained through this innovative method, and analyze its chemical and physical properties using Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and mechanical property analysis with the mean values for the elasticity module, the resistance to tensile strength and the tensile strength. The results indicate that this new process of obtaining the NCC did not modify the chemical structure of the chitosan. The structure of the film surface created was homogeneous and the mechanical properties emphasized the plastifying effect of glycerol under NCC. The thermogravimetric analysis of NCC indicated greater stability in the polysaccharide structure of the nanocrystalline, due to an increased crystalline region compared to the CA which was confirmed by DSC.


Assuntos
Quitosana/química , Nanopartículas/química , Configuração de Carboidratos , Cristalização , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração
2.
Braz J Med Biol Res ; 50(6): e5977, 2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28538835

RESUMO

Generalized bone loss can be considered an extra-articular manifestation of rheumatoid arthritis (RA) that may lead to the occurrence of fractures, resulting in decreased quality of life and increased healthcare costs. The peptide ghrelin has demonstrated to positively affect osteoblasts in vitro and has anti-inflammatory actions, but the studies that correlate ghrelin plasma levels and RA have contradictory results. We aimed to evaluate the correlation between total ghrelin plasma levels, density of ghrelin-immunoreactive cells in the gastric mucosa, and bone mineral density (BMD) in twenty adult women with established RA with 6 months or more of symptoms (mean age of 52.70±11.40 years). Patients with RA presented higher ghrelin-immunoreactive cells density in gastric mucosa (P=0.008) compared with healthy females. There was a positive relationship between femoral neck BMD and gastric ghrelin cell density (P=0.007). However, these same patients presented a negative correlation between plasma ghrelin levels and total femoral BMD (P=0.03). The present results indicate that ghrelin may be involved in bone metabolism of patients with RA. However, the higher density of ghrelin-producing cells in the gastric mucosa of these patients does not seem to induce a corresponding elevation in the plasma levels of this peptide.


Assuntos
Artrite Reumatoide/metabolismo , Densidade Óssea , Células Endócrinas/citologia , Grelina/sangue , Adulto , Artrite Reumatoide/fisiopatologia , Índice de Massa Corporal , Densidade Óssea/fisiologia , Contagem de Células , Células Endócrinas/metabolismo , Feminino , Colo do Fêmur/anatomia & histologia , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Pessoa de Meia-Idade , Células Parietais Gástricas/metabolismo , Células Parietais Gástricas/patologia
3.
Rev. bras. plantas med ; 17(1): 76-104, Jan-Mar/2015. tab, graf
Artigo em Português | LILACS | ID: lil-742923

RESUMO

Este trabalho teve por objetivo identificar as plantas medicinais de uso popular e o perfil socioeconômico de seus usuários em área urbana de Ouro Preto, MG. O levantamento utilizou entrevistas semiestruturadas e amostragem aleatória, perfazendo 10% das residências. O grau de conhecimento sobre plantas medicinais foi medido pelo número de espécies citadas. Analisou-se a relação entre o saber popular sobre as plantas medicinais e características socioeconômicas dos entrevistados (renda, escolaridade, sexo, idade e forma de aquisição do conhecimento). Foram questionadas 6.713 pessoas, onde mais de 90% usam plantas medicinais para se tratarem. Identificou-se 342 espécies, reunidas em 94 famílias. Para cada espécie foram referidos os nomes populares, hábito, procedência, uso medicinal, parte usada, e forma de preparo. As principais moléstias tratadas com plantas foram: diarreia, insônia, gripe, hidropisia, distúrbios hepáticos, renais e do trato respiratório. Há um grande número de espécies nativas utilizadas. Dentre as exóticas, a maioria é de origem europeia. O uso místico de espécies, embora presente na cultura popular do município, foi pouco citado. Algumas espécies identificadas figuram na lista das espécies ameaçadas de extinção. O grau de conhecimento sobre plantas medicinais pela população de Ouro Preto independe, tanto do nível econômico, como da escolaridade ou do sexo. A idade e a forma de aquisição do conhecimento influenciam no saber popular das ervas medicinais. As pessoas com maior saber popular sobre as plantas adquiriram esses conhecimentos principalmente pelo costume familiar, por livros, ou por outras pessoas. Pessoas mais jovens conhecem menos espécies medicinais que as mais idosas, sugerindo risco de perda desse conhecimento tradicional. A grande riqueza de plantas citadas neste trabalho denota a importância de estudos etnobotânicos no resgate do conhecimento tradicional em áreas urbanas, tanto pelo seu valor histórico-cultural, como pela importância científica.


This work aimed to identify the medicinal plants of popular use and the socioeconomic profile of the users in the urban area of Ouro Preto, state of Minas Gerais, Brazil. The survey was carried out with random sampling and semi-structured interviews, amounting to 10% of households. The degree of knowledge about medicinal plants was measured by the number of species mentioned. The relationship between the popular knowledge about medicinal plants and the socioeconomic characteristics of the users (income, education, gender, age and type of knowledge acquisition) was also studied. In this survey, 6,713 inhabitants were questioned, of whom more than 90% use medicinal plants. A total of 342 species grouped in 94 families were identified. The popular names, growth habit, habitat, medicinal uses, part used and method of preparation are listed for each identified species. The main ailments treated with plants were diarrhea, insomnia, flu, dropsy and liver, renal and respiratory tract disorders. There is a large number of native species. Among the exotic ones, most are of European origin. The spiritual use of species, although present in the popular culture of the city, was negligible. Some species figure on the Brazilian red lists. It was noted that knowledge of medicinal plants by the population of Ouro Preto, in species richness, is not related to income, class, educational level and gender. The age and manner of acquisition of empirical knowledge about medicinal plants are associated with the number of species listed. Persons with greater popular knowledge about medicinal plants acquired information through family tradition, books and from other persons. Younger persons know fewer medicinal plants than the older ones, what suggests a loss of this traditional knowledge. The richness of the plants mentioned in this paper demonstrates the importance of ethnobotanical studies in the rescue of traditional knowledge in urban areas, for its scientific, historical and cultural values.


Assuntos
Humanos , Masculino , Feminino , Plantas Medicinais/anatomia & histologia , Classe Social , Área Urbana , Participação da Comunidade/estatística & dados numéricos , Etnobotânica/métodos
4.
Genet Mol Res ; 9(4): 1974-9, 2010 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-20927715

RESUMO

The bovine tick Rhipicephalus (Boophilus) microplus causes major losses in cattle production systems in tropical regions. Bos indicus breeds are more resistant to ticks than B. taurus breeds. Resistance genes could be an alternative to control this parasite. We examined the pattern of gene expression of three calcium-binding-protein genes: translationally controlled tumor protein 1 (TPT1), allergen Bos d3 (S100A7), calcium channel protein transient receptor potential vanilloid 6 (TRPV6), and the cysteine proteinase inhibitor gene (CST6). These genes were selected from cDNA libraries prepared from skin biopsies taken from resistant and susceptible Gyr x Holstein F2 animals. These biopsies were also used to study the expression level of these genes through real-time PCR analysis. The relative expression levels of the S100A7, TPT1, TRPV6, and CST6 genes were 2.01 ± 0.6, 1.32 ± 0.9, 1.53 ± 1.2, and 2.03 ± 0.7 times higher in the susceptible group, respectively. Skin lesion tissue from the susceptible animals showed significantly more mRNA transcripts of these genes in comparison with the resistant animals (P = 0.001). However, this hypersensitivity does not seem to protect the susceptible animals against tick infestation.


Assuntos
Bovinos/genética , Expressão Gênica , Interações Hospedeiro-Parasita , Rhipicephalus/fisiologia , Animais , Sequência de Bases , Primers do DNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
Theriogenology ; 68(4): 626-32, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17590427

RESUMO

Bos indicus cows usually have better reproductive performance in tropical and subtropical regions than Bos taurus cows, presumably due to their better adaptation to tropical environments. The aim of this study was to evaluate the developmental competence and expression of the Hsp 70.1 gene in immature oocytes from B. taurus (Holstein) and B. indicus (Gyr) dairy cows raised in a tropical region. Cumulus-oocyte complexes were obtained by transvaginal ultrasound-guided follicle aspiration between spring and early autumn, and subjected to in vitro maturation and fertilization. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa media with 10% fetal calf serum; Grade 1 blastocysts were transferred to synchronized crossbred recipients. The total RNA was extracted from immature Holstein and Gyr oocytes (three pools for each breed) and relative quantification of the Hsp 70.1 transcripts was performed by real time PCR after reverse transcription. Cleavage and blastocyst rates were greater (P<0.05) for Gyr (n=390 oocytes) than Holstein (n=505) breed (66.7% versus 53.1% of cleavage and 19.6% versus 10.8% of blastocysts, respectively), but pregnancy rates were not significantly different following transfer to recipients (44.5% for 36 Gyr embryos; 60% for 10 Holstein embryos). Holstein immature oocytes had a higher level (P<0.05) of Hsp 70.1 relative expression (1.82+/-0.22; mean+/-S.E.M.) than Gyr oocytes (1.12+/-0.11). In conclusion, Gyr oocytes obtained in a tropical region were less subject to stress and more likely to develop (after IVF) than Holstein oocytes.


Assuntos
Bovinos/fisiologia , Transferência Embrionária/veterinária , Desenvolvimento Embrionário/fisiologia , Fertilização in vitro/veterinária , Proteínas de Choque Térmico HSP70/fisiologia , Oócitos/fisiologia , Animais , Brasil , Feminino , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Masculino , Oócitos/crescimento & desenvolvimento , Oócitos/metabolismo , Gravidez , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Clima Tropical
6.
Genet Mol Res ; 5(3): 513-24, 2006 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-17117367

RESUMO

Losses caused by bovine tick burdens in tropical countries have a tremendous economic impact on production systems. Besides reducing production, this parasite can cause death in the most susceptible animals. The use of commercial acaricides has been the major method of control, but their misuse has led to tick resistance to many chemicals. More recently, vaccines have been used in some countries without solving the problem completely. An alternative could be the development of resistant animals and the use of genetic markers and candidate genes that could help with the enormous task of selecting resistant animals. The bovine lymphocyte antigen genes (BoLA) have been shown to be associated with some parasitic infestations and disease incidence. Thus, the objective of the present study was to determine the association of BoLA-DRB3.2 alleles with tick resistance in cattle. The study was conducted on 231 F2 (Gyr x Holstein) animals that were artificially infested with 10,000 tick larvae. Log of tick count +1 was used as the dependent variable in a mixed animal model with allele substitution effects in addition to fixed effects of year and season at tick count, sex of calves, age of animal at tick count, hair type (short-straight, short-curl, long-straight, and long-curl), coat color (white, >75% white, 50- 75% white, and 25-50% white), and additive genetic, permanent environmental and residual effects as random. Females showed fewer ticks than males. Animals with short-straight hair were more resistant to tick infestation than animals with long-curl hair, and animals with whiter coat color also had fewer ticks. An association between BoLA alleles and lower tick number was found for alleles DRB3.2 *18, *20 and *27 at the 5% significance level. Also, one allele (DRB3.2*16) showed an association at the 10% level. Allele *27 was the most frequent in the population (30.7%), followed by alleles *16 (10.8%), *20 (8.7%) and *18 (2.4%). These results suggest that BoLA-DRB3.2 alleles could be used to help in the selection of animals resistant to tick infestation. However, further studies involving a larger population of cattle in combination with other BoLA genes may help to understand the mechanisms of resistance to parasites.


Assuntos
Alelos , Doenças dos Bovinos/genética , Bovinos/genética , Antígenos de Histocompatibilidade Classe II/genética , Infestações por Carrapato/veterinária , Animais , Bovinos/imunologia , Bovinos/parasitologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Feminino , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Masculino , Modelos Genéticos , Reação em Cadeia da Polimerase , Característica Quantitativa Herdável , Estações do Ano , Infestações por Carrapato/genética , Infestações por Carrapato/imunologia
7.
Arq. bras. med. vet. zootec ; 58(3): 401-407, jun. 2006. tab, graf
Artigo em Português | LILACS | ID: lil-443595

RESUMO

Investigou-se a existência de polimorfismo no gene da leptina (gene da obesidade) entre varrões da raça nativa Piau (porco tipo banha) e matrizes mestiças de raças comerciais (Landrace/Large White e Landrace/Large White com Pietrain), selecionadas para peso e precocidade. Oito pares de primers foram desenhados a partir da seqüência disponível no GenBank (U66254), usada, neste trabalho, como seqüência de referência. Amostras de DNA foram extraídas de células sangüíneas brancas utilizando-se solução de fenol:clorofórmio, após tratamento com proteinase K. Os fragmentos gerados por amplificação da reação em cadeia da polimerase foram purificados e seqüenciados em seqüenciador automático. As seqüências de nucleotídeos, obtidas a partir do DNA das raças comerciais de suíno, apresentaram maior similaridade com a seqüência de referência, e as seqüências geradas a partir do DNA dos animais nativos divergiram de ambas em algumas posições. Dos 28 polimorfismos encontrados, oito foram observados em apenas uma das três seqüências geradas a partir do DNA das raças nativas. Doze estavam presentes em duas seqüências, e os oito polimorfismos restantes foram encontrados nos três animais nativos.


Leptin gene (obese gene) polymorphism was investigated in Piau boars (a fat, native breed) and sows from commercial strains (Landrace/Large White and Landrace/Large White by Pietrain) chosen for rapid growth and early sexual maturity. Eight pairs of primers designed using the sequence available from GenBank (access n° U66254) were identified as the reference sequence in this project. DNA samples were extracted from white blood cells using phenol:chloroform solution, after treatment with proteinase K. Fragments generated by amplification of the Polymerase Chain Reaction were purified and sequenced in an automatic sequencer. Nucleotide sequences obtained from DNA of commercial swine breeds were similar to the reference sequence; whereas sequences generated from native breed DNA diverged from the reference sequence and from domestic breed DNA. Of the 28 polymorphisms found, eight were observed in only one of the three sequences generated from DNA of native breeds. Twelve polymorphisms were present in two sequences and the eight remaining polymorphisms were found in all three categories of DNA.


Assuntos
Leptina/isolamento & purificação , Polimorfismo Genético/fisiologia , Suínos
8.
Genet. mol. res. (Online) ; 5(3): 513-524, 2006. tab
Artigo em Inglês | LILACS | ID: lil-441047

RESUMO

Losses caused by bovine tick burdens in tropical countries have a tremendous economic impact on production systems. Besides reducing production, this parasite can cause death in the most susceptible animals. The use of commercial acaricides has been the major method of control, but their misuse has led to tick resistance to many chemicals. More recently, vaccines have been used in some countries without solving the problem completely. An alternative could be the development of resistant animals and the use of genetic markers and candidate genes that could help with the enormous task of selecting resistant animals. The bovine lymphocyte antigen genes (BoLA) have been shown to be associated with some parasitic infestations and disease incidence. Thus, the objective of the present study was to determine the association of BoLA-DRB3.2 alleles with tick resistance in cattle. The study was conducted on 231 F2 (Gyr x Holstein) animals that were artificially infested with 10,000 tick larvae. Log of tick count +1 was used as the dependent variable in a mixed animal model with allele substitution effects in addition to fixed effects of year and season at tick count, sex of calves, age of animal at tick count, hair type (short-straight, short-curl, long-straight, and long-curl), coat color (white, >75% white, 50- 75% white, and 25-50% white), and additive genetic, permanent environmental and residual effects as random. Females showed fewer ticks than males. Animals with short-straight hair were more resistant to tick infestation than animals with long-curl hair, and animals with whiter coat color also had fewer ticks. An association between BoLA alleles and lower tick number was found for alleles DRB3.2 *18, *20 and *27 at the 5% significance level. Also, one allele (DRB3.2*16) showed an association at the 10% level. Allele *27 was the most frequent in the population (30.7%), followed by alleles *16 (10.8%), *20 (8.7%) and *18 (2.4%)...


Assuntos
Animais , Masculino , Feminino , Alelos , Doenças dos Bovinos/genética , Bovinos/genética , Antígenos de Histocompatibilidade Classe II/genética , Infestações por Carrapato/veterinária , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Bovinos/imunologia , Bovinos/parasitologia , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Modelos Genéticos , Reação em Cadeia da Polimerase , Característica Quantitativa Herdável , Estações do Ano , Infestações por Carrapato/genética , Infestações por Carrapato/imunologia
9.
J Travel Med ; 7(5): 275-82, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11231212

RESUMO

BACKGROUND: Malaria represents one of the most important infectious disease threats to deployed military forces; most personnel from developed countries are nonimmune personnel and are at high risk of infection and clinical malaria. This is especially true for forces deployed to highly-endemic areas in Africa and Southeast Asia where drug-resistant malaria is common. METHODS: We conducted an outbreak investigation of malaria cases in Angola where a total of 439 nonimmune Brazilian troops were deployed for a 6-month period in 1995-1996. A post-travel medical evaluation was also performed on 338 (77%) of the 439 soldiers upon return to Brazil. Questionnaire, medical record, thick/thin smear, and serum anti-Plasmodium falciparum antibody titer (by IFA) data were obtained. Peak serum mefloquine (M) and methylmefloquine (MM) metabolite levels were measured in a subsample of 66 soldiers (42 cases, 24 nonmalaria controls) who were taking weekly mefloquine prophylaxis (250 mg). RESULTS: Seventy-eight cases of malaria occurred among the 439 personnel initially interviewed in Angola (attack rate = 18%). Four soldiers were hospitalized, and 3 subsequently died of cerebral malaria. Upon return to Brazil, 63 (19%) of 338 soldiers evaluated were documented to have had clinical symptoms and a diagnosis of malaria while in Angola. In addition, 37 (11%) asymptomatically infected individuals were detected upon return (< 1% parasitemia). Elevated, post-travel anti-P. falciparum IFA titers (> or = 1:64) were seen in 101 (35%) of 292 soldiers tested, and was associated with a prior history of malaria in-country (OR = 3.67, 95% CI 1.98-6.82, p <.001). Noncompliance with weekly mefloquine prophylaxis (250 mg) was associated with a malaria diagnosis in Angola (OR = 3.75, 95% CI 0.97-17.41, p =.03) but not with recent P. falciparum infection (by IFA titer). Mean peak levels (and ratios) of serum M and MM were also found to be lower in those who gave a history of malaria while in Angola. CONCLUSIONS: Malaria was a significant cause of morbidity among Brazilian Army military personnel deployed to Angola. Mefloquine prophylaxis appeared to protect soldiers from clinical, but not subclinical, P. falciparum infections. Mefloquine noncompliance and an erratic chemoprophylaxis prevention policy contributed to this large outbreak in nonimmune personnel. This report highlights the pressing need for development of newer, more efficacious and practical, prophylactic drug regimens that will reduce the malaria threat to military forces and travelers.


Assuntos
Surtos de Doenças , Malária Falciparum/epidemiologia , Militares , Angola/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , Antimaláricos/uso terapêutico , Brasil , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/prevenção & controle , Mefloquina/uso terapêutico , Cooperação do Paciente , Plasmodium falciparum/imunologia
10.
Appl Biochem Biotechnol ; 63-65: 257-68, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-18576086

RESUMO

Glucose dehydrogenase (GDH) from Bacillus megaterium was immobilized using aminopropyl controlled-pore silica (CPS, average pore sizes of 170 and 500 A) as a support and glutaraldehyde as a bifunctional crosslinking agent. The CPS-immobilized enzyme could be reused 12 times and the best results were obtained using aminopropyl CPS-500 and bovine serum albumin as a feeder for stabilizing the protein layer on the support. DEAE-Sephadex (A-25 and A-50) was also used as a support for immobilizing GDH, with yields of around 42% for A-25 and 25-30% for A-50. The effect of pH on the immobilization procedure showed pH 6.5 to be better than pH 7.5 with respect to the recovery of enzyme activity. Both preparations of DEAE-Sephadex immobilized GDH could be reused several times and were thermostable at 40 degrees C for 7 h. The kinetic parameters as Michaelis constant and maximum rate were determined for the immobilized enzyme and compared with those for the freeform.

11.
Appl Biochem Biotechnol ; 63-65: 305-14, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-18576089

RESUMO

Astaxanthin is a diketo-dihydroxy-carotenoid produced by Phaffia rhodozyma, a basidiomicetous yeast. A low-cost fermentation medium consisting of raw sugarcane juice and urea was developed to exploit the active sucrolytic/urelolytic enzyme apparatus inherent to the yeast. As compared to the beneficial effect of 0.1 g% urea, a ready nitrogen source, mild phosphoric pre inversion of juice sucrose to glucose and fructose, promptly fermentable carbon sources, resulted in smaller benefits. Corn steep liquor (CSL) was found to be a valuable supplement for both yeast biomass yield (9.2 g dry cells/L) and astaxanthin production (1.3 mg/g cells). Distillery effluent (vinace), despite only a slightly positive effect on yeast growth, allowed for the highest pigment productivity (1.9 mg/g cells). Trace amounts of Ni2 (1 mg/L, as a cofactor for urease) resulted in controversial effects, namely, biomass decrease and astaxanthin increase, with no effect on the release (and uptake) of ammonium ion from urea. Since the synthesized astaxanthin is associated with the yeast cell and the pigment requires facilitated release for aquaculture uses (farmed fish meat staining), an investigation of the yeast cell wall was undertaken using detergent-treated cells. The composition of the rigid yeast envelope was found to be heterogeneous. Its partial acid or enzymatic depolymerization revealed glucose and xylose as common monomeric units of the cell-wall glycopolymers. Yeast cell-wall partial depolymerization with appropriate hydrolases may improve the pigment bioavailability for captive aquatic species and poultry.

12.
Appl Biochem Biotechnol ; 63-65: 327-38, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-18576091

RESUMO

Since natural substances like pseudoxanthins exert a positive effect on the cellulogenic ability of Acetobacter xylinum when producing cellulosic pellicles suitable for skin burn therapy, new defined and complex modulators were sought. Ca2+ and Mg2+ (4 mM) were strongly stimulatory. Na+ had no effect and K+ was inhibitory. Ammonium dihydrogen phosphate (0.12 g/L) ensured the same nitrogen supply as the same concentration of yeast extract as measured by cellomembrane dry wt./yield albeit higher yeast extract supplies produced thicker membranes. Corn steep liquor (CSL) was also progressively beneficial from 0.125 to 0.5 mL/L, and this yield could be further improved by the combination of CSL with a tea infusion (source of caffeine). Uridine (precursor for UDP-Glc, sugar donor in cellulose biosynthesis), guanine, guanosine, and its butirylated derivatives (precursors for the positive modulator of cellulose synthetase, di-cGMP) resulted in only moderate stimulation. Sodium phytate and betaine were also slightly stimulatory. The fibrilar product from a new Acetobacter isolate (Ax-M) was characterized as cellulose by comparison with the solid-state(13)C-NMR of algal cellulose. Its X-ray diffractogram was a confirmatory analysis. After incorporation of tamarind xyloglucan to previously air-dried cellulosic pellicles, diffractometry displayed only slight differences. Mercerized (5M NaOH) fresh cellulosic biofilms underwent drastic size reduction (3.5-fold), turning compact nut still flexible if maintained wet.

13.
Appl Biochem Biotechnol ; 57-58: 413-22, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8669908

RESUMO

Growth of the yeast Phaffia rhodozyma was carried out in a simplified medium based on less expensive nutrient sources, such as diluted sugar cane juice, urea, and sodium phosphate. The usual content of the astaxanthin, an oxygenated pink carotenoid useful for fish flesh staining, was improved along with with good cell yields (respective values of > 1300 micrograms/g cells and > 5 g cells/L were observed). Yeast invertase and urease must therefore play an important role in the implementation of low-cost culture media.


Assuntos
Carotenoides/biossíntese , Leveduras/crescimento & desenvolvimento , beta Caroteno/análogos & derivados , Carbono/metabolismo , Controle de Custos , Meios de Cultura/economia , Estrutura Molecular , Nitrogênio/metabolismo , Xantofilas , Leveduras/metabolismo
14.
Appl Biochem Biotechnol ; 51-52: 197-210, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7668847

RESUMO

Toxins, enzymes, and biologically active peptides are the main components of snake venoms from the genus Bothrops. Following the venom inoculation, the local effects are hemorrhage, edema, and myonecrosis. Nineteen different species of Brazilian Bothrops were screened for protein content and L-amino acid oxidase activity. B. cotiara, formerly found in the South of Brazil, is now threatened with extinction. Its venom contains a highly hemorrhagic fraction and, as expected from the deep yellow color of the corresponding lyophilized powder, a high L-amino acid oxidase (LAO) activity was also characterized. Flavin adenine dinucleotide (FAD) is its associate coenzyme. B. cotiara venom LAO catalyzed the oxidative deamination of several L-amino acids, and the best substrates were methionine, leucine, tryptophan, and phenylalanine, hence, its potential application for the use of biosensors for aspartame determination and for the removal of amino acids from plasma. High levels for LAO were also found in other species than B. cotiara. In addition, the technique of isoelectric focusing (IEF) was employed as a powerful tool to study the iso- or multi-enzyme distribution for LAO activity in the B. cotiara snake venom.


Assuntos
Aminoácido Oxirredutases/metabolismo , Bothrops/metabolismo , Venenos de Serpentes/química , Aminoácido Oxirredutases/química , Aminoácidos/metabolismo , Animais , Bothrops/genética , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Flavina-Adenina Dinucleotídeo/química , Hemorragia/induzido quimicamente , Focalização Isoelétrica , L-Aminoácido Oxidase , Proteínas/química , Ratos , Ratos Wistar , Venenos de Serpentes/efeitos adversos , Análise Espectral , Zinco/química
15.
Refract Corneal Surg ; 8(1): 84-7, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1554644

RESUMO

BACKGROUND: The principle of refractive corneal lamellar surgery rests on the modification of corneal shape after the removal of a superficial disk with a microkeratome. The 150-microns-thick disk is easily torn, rotated or decentered by the traditional eight-bite running suture, producing irregular astigmatism which is the major cause of visual deficit after these procedures. METHODS: We propose a new suture technique, designated the BRA suture, which we have used in more than 300 cases of various types of refractive corneal lamellar procedures. Based on the overlay concept, the suture is anchored in four points of the nonoperated corneal periphery. RESULTS: With this technique, the iatrogenic irregular astigmatism induced by the suture has been eliminated and corneal scars significantly reduced. This suture also decreases surgical time, accelerates visual recovery, and increases patient comfort due to its early removal. CONCLUSIONS: We consider this the ideal suture for refractive corneal lamellar surgery due to its effectiveness, simplicity, and safety.


Assuntos
Transplante de Córnea/métodos , Técnicas de Sutura , Astigmatismo/prevenção & controle , Humanos , Procedimentos Cirúrgicos Refrativos , Acuidade Visual , Cicatrização
16.
Pulmäo RJ ; 1(1): 30-32, 1991. ilus
Artigo em Português | LILACS | ID: lil-661986

RESUMO

Os autores relatam o caso de um paciente do sexo masculino de 60 anos de idade, assintomático respiratório, não tabagista, cuja radiografia de tórax evidenciava a presença de um nódulo pulmonar localizado no segmento 10. Após complementação do estudo radiológico com tomografia convencional e arteriografia foi confirmado o diagnóstico de sequestro pulmonar. A seguir tecem comentários acerca do quadro clínico e radiológico desta afecção além de considerações sobre a patogenia e, finalmente, o tratamento proposto no caso


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Sequestro Broncopulmonar/complicações , Sequestro Broncopulmonar/diagnóstico , Sequestro Broncopulmonar/terapia
17.
Arq. biol. tecnol ; 32(3): 575-87, ago. 1989. ilus, tab
Artigo em Inglês | LILACS | ID: lil-74261

RESUMO

An inducible L-fucose dehydrogenase from the yeast-like fungus Pullularia pullulans was purified and studied. The enzyme catalyses the oxidation of L-fucose to L-fuconic acid possibly throught its unstable L-funcono-lactone. the enzyme was purified to hemogeneity by a sequence of protamine sulfate treatment, ammonium sulfate fractionation, gel filtration on Sephadex G-100, and DEAE-cellulose chromatography. This sequence resulted in an 87 fold purification. The apparent molecular weight determined by gel filtration and SDS polyacrilamide gel electrophoresis was 40 000. the dehydrogenase was NAD-especific and showed a high sugar substrate specificity. Of several D-and L-aldoses tested only L-fucose, L-galactose and-arabinose served as substrates. The maximum velocity for the reaction was at 33- and pH 10.5. Under these conditions, the Km values, and D-arabinose, respectively. The enzyme was strongly inhibited by thiol reagents, heavy metal ions, and was not particularly stable. At 4- it rapidly los activity, but remained active for two months when maintained at -20-. The enzyme has been used to quantativate L-fucose


Assuntos
Desidrogenases de Carboidrato/metabolismo , Fungos/enzimologia
18.
J Surg Oncol ; 34(2): 133-5, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2433547

RESUMO

The authors present the results of a preliminary study on the use of a concentrated dose of 13 Gy in 48 hours in the treatment of cancer of the cervix, especially for haemostatic and antialgic purposes and mostly as a first part of a split course of radiotherapy. In 13 patients with early stages of the disease, the method was used as an emergency treatment with good response in 84.6% of the cases without serious complications. In 43 patients with advanced disease, the concentrated dose was generally repeated for palliation and relieved symptoms in about 72% of the cases but with complications in 16.3%. The authors recommend this method only when absolutely necessary to stop severe haemorrhage and suggest that patients with good response to the first flash course should continue treatment with conventional fractionation, bearing in mind the tolerance of the normal tissues.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Radioterapia de Alta Energia/efeitos adversos , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Feminino , Seguimentos , Hemorragia/radioterapia , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Cuidados Paliativos , Dosagem Radioterapêutica
19.
J Surg Oncol ; 33(3): 198-202, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2430143

RESUMO

A method is presented of rapid, palliative radiotherapy for carcinoma of the breast, composed of two sessions of 6.5 or 8.5 Gy delivered at a 48-hour interval. The radiobiological equivalence of this unconventional technique is presented. Our preliminary results in a series of 80 patients were published in 1978. The present report is based on the analysis of 112 patients with T4 of the breast submitted to the "flash" dose, from March 1978 to December 1981. The method was used not only for relief of symptoms such as pain and hemorrhage, but also as part of intensive radiotherapy in all patients with good response and with no manifestation of distant dissemination so that they were able to resume treatment 2.5 or 3 weeks later, with conventional fractionation. Some of these patients became operable. About half of the cases had castration and/or hormone therapy and/or chemotherapy. In the group of patients with T4M0, 59.8% were alive after more than 1 year, and of them, 43.7% had no evidence of disease. These encouraging results suggest that this method be advocated in T4 of the breast because of its rapidity and good tolerance with no significant complications.


Assuntos
Neoplasias da Mama/radioterapia , Adulto , Idoso , Radioisótopos de Cobalto , Feminino , Humanos , Pessoa de Meia-Idade , Cuidados Paliativos , Teleterapia por Radioisótopo , Dosagem Radioterapêutica , Estudos Retrospectivos
20.
Radiol. bras ; 17(3): 153-7, 1984.
Artigo em Português | LILACS | ID: lil-26040

RESUMO

Os autores relatam um caso de hemangioma cavernoso de figado, fazem uma revisao da literatura e discutem o papel dos metodos de diagnostico pr imagem na indentificacao desta lesao


Assuntos
Adulto , Humanos , Feminino , Hemangioma Cavernoso , Neoplasias Hepáticas , Angiografia , Diagnóstico Diferencial , Cintilografia , Tomografia Computadorizada por Raios X
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