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1.
Artigo em Inglês | MEDLINE | ID: mdl-38644084

RESUMO

INTRODUCTION AND AIMS: Irritable bowel syndrome (IBS) is one of the most frequent functional gastrointestinal disorders. Prevalence worldwide is estimated at 11%. There is little information on the prevalence of the other functional bowel disorders (FBDs). Our aim was to establish the prevalence of IBS and other FBDs according to the Rome IV criteria, in Uruguay. MATERIALS AND METHODS: An observational, population-based prevalence study was conducted. Data were collected through an online questionnaire, utilizing the Rome IV criteria. RESULTS: Of the 1,052 participants (79% women, mean patient age 44 years), 47.2% met the Rome IV diagnostic criteria for at least one of the FBDs analyzed. Functional constipation (FC) was the most frequent, at 18.7% (16.4-21.1), followed by IBS at 17.1% (14.9-19.4) and functional diarrhea (FD) at 15.4% (13.3-17.6). IBS with constipation (IBS-C) was the most frequent IBS subtype (35%) and the IBS with diarrhea (IBS-D) subtype predominated in men. All FBDs were more prevalent in women and youths. Of the survey participants with a FBD, 59% stated that they perceived no worsening of their symptoms related to the COVID-19 pandemic. CONCLUSIONS: Ours is the first prevalence study on FBDs conducted on the Uruguayan general population. Half of the participants surveyed presented with a FBD analyzed in the study. FC was the most frequent, followed by IBS and FD. The prevalence rate of IBS was the highest, based on the Rome IV diagnostic criteria, and constipation was the most frequent subtype.

2.
J Invest Surg ; 33(1): 8-14, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29764253

RESUMO

Purpose: Evaluate the efficacy of hydroxytyrosol in the local treatment of inflammatory colitis. Currently, the existing treatments for inflammatory bowel diseases does not cure the disease and it is associated with high rates of side effects and complications. Hydroxytyrosol is a phenyl-ethyl-alcohol derived from the hydrolysis of oleuropein and present in olive oil, previous studies have demonstrated the anti-inflammatory effect of dietary hydroxytyrosol supplement, with no toxicity. Materials & Methods: Colitis has been induced by using Trinitrobenzene Sulfonic Acid at 40 rats. They were divided into four groups randomly: 10 rats without treatment; 10 rats with pectin/alginate mixture; 10 rats treated with pectin/alginate + olive oil; 10 rats treated with pectin/alginate + olive oil + hydroxytyrosol. Animals were sacrificed 10 days after induction of trinitrobenzene sulfonic acid, receiving 5 days of continuous treatment. Samples of the rectal area were studied and observed under a microscope to determine the damage by Hunter scoring modified, assessing inflammatory infiltration, number of intestinal walls involved, damage to the mucosal architecture, and edema. Results: When the rectum was analyzed in a global way, nonsignificant differences were observed; however, when performing an individualized analysis, statistically significant differences in the inflammatory infiltrate are present in the samples, which were evaluated using the ANOVA and Student-T statistics. Conclusions: Local treatment with the natural antioxidant hydroxytyrosol combined with pectin/alginate and olive oil of inflammatory bowel disease has been shown to be effective against inflammatory infiltration of TNBS-induced colitis.


Assuntos
Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Colite/tratamento farmacológico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Álcool Feniletílico/análogos & derivados , Alginatos/administração & dosagem , Alginatos/efeitos adversos , Animais , Anti-Inflamatórios/efeitos adversos , Antioxidantes/efeitos adversos , Colite/induzido quimicamente , Colite/patologia , Modelos Animais de Doenças , Quimioterapia Combinada/efeitos adversos , Quimioterapia Combinada/métodos , Enema , Estudos de Viabilidade , Feminino , Humanos , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Azeite de Oliva/administração & dosagem , Azeite de Oliva/efeitos adversos , Pectinas/administração & dosagem , Pectinas/efeitos adversos , Álcool Feniletílico/administração & dosagem , Álcool Feniletílico/efeitos adversos , Ratos , Ratos Wistar , Reto/efeitos dos fármacos , Reto/imunologia , Reto/patologia , Ácido Trinitrobenzenossulfônico/toxicidade
3.
Food Funct ; 8(5): 2053-2061, 2017 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-28504296

RESUMO

Insulin-resistance (IR), of increased cardiovascular risk, is characterized by the production of altered VLDL with greater atherogenicity. Dietary fatty acids influence the type of circulating VLDL. But, it is not clear how dietary fatty acids impact VLDL characteristics in IR. AIM: to evaluate the effects of n-3, n-6 and n-9 fatty acid supplementation on preventing atherogenic alterations in VLDL, in a diet-induced IR rat model. Male Wistar rats (180-200 g) were fed: standard diet (control, n = 8) and a sucrose rich diet (30% sucrose in water/12 weeks, SRD; n = 24). Simultaneously, SRD was subdivided into SRD-C (standard diet), and three other groups supplemented (15% w/w) with: fish oil (SRD-n3), sunflower oil (SRD-n6) and high oleic sunflower oil (SRD-n9). Lipid profile, free fatty acids, glucose, and insulin were measured. Isolated VLDL (d < 1.006 g ml-1) was characterized by chemical composition and size (size exclusion-HPLC). In comparison with SRD-C: SRD-n3 showed an improved lipoprotein profile (p < 0.01), with lower levels of insulin and HOMA-IR (p < 0.05). SRD-n6 showed increased levels of HDL-cholesterol and lower insulin levels. SRD-n9 did not exhibit differences in lipid and IR profile, and even favored weight gain and visceral fat. Only SRD-n3 prevented the alterations in VLDL-TG% (54.2 ± 4.4% vs. 68.6 ± 8.2, p < 0.05) and showed lower large VLDL-% (22.5[19.7-35.6] vs. 49.1[15.5-82.0], p < 0.05), while SRD-n6 and SRD-n9 did not show effects. CONCLUSION: In IR, while n-3 PUFA showed expected favorable effects, supplementation with n-6 PUFA and n-9 MUFA did not prevent atherogenic alterations of VLDL. Thus, the recommendations of supplementation with these fatty acids in general diet should be revised.


Assuntos
VLDL-Colesterol/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-6/administração & dosagem , Resistência à Insulina , Animais , Doenças Cardiovasculares/metabolismo , Suplementos Nutricionais/análise , Modelos Animais de Doenças , Ácidos Graxos , Humanos , Insulina/sangue , Masculino , Ratos , Ratos Wistar , Triglicerídeos/sangue
4.
EBioMedicine ; 9: 140-147, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27333048

RESUMO

BACKGROUND: In many countries, gastric cancer is not diagnosed until an advanced stage. An Internet-based e-learning system to improve the ability of endoscopists to diagnose gastric cancer at an early stage was developed and was evaluated for its effectiveness. METHODS: The study was designed as a randomized controlled trial. After receiving a pre-test, participants were randomly allocated to either an e-learning or non-e-learning group. Only those in the e-learning group gained access to the e-learning system. Two months after the pre-test, both groups received a post-test. The primary endpoint was the difference between the two groups regarding the rate of improvement of their test results. FINDINGS: 515 endoscopists from 35 countries were assessed for eligibility, and 332 were enrolled in the study, with 166 allocated to each group. Of these, 151 participants in the e-learning group and 144 in the non-e-learning group were included in the analysis. The mean improvement rate (standard deviation) in the e-learning and non-e-learning groups was 1·24 (0·26) and 1·00 (0·16), respectively (P<0·001). INTERPRETATION: This global study clearly demonstrated the efficacy of an e-learning system to expand knowledge and provide invaluable experience regarding the endoscopic detection of early gastric cancer (R000012039).


Assuntos
Gastroenterologistas/educação , Desenvolvimento de Programas , Neoplasias Gástricas/diagnóstico , Detecção Precoce de Câncer , Gastroenterologistas/psicologia , Gastroscopia , Humanos , Internet , Aprendizagem , Avaliação de Programas e Projetos de Saúde
9.
Phytopathology ; 97(12): 1664-9, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18943731

RESUMO

ABSTRACT Production of cacao in tropical America has been severely affected by fungal pathogens causing diseases known as witches' broom (WB, caused by Moniliophthora perniciosa), frosty pod (FP, caused by M. roreri) and black pod (BP, caused by Phytophthora spp.). BP is pan-tropical and causes losses in all producing areas. WB is found in South America and parts of the Caribbean, while FP is found in Central America and parts of South America. Together, these diseases were responsible for over 700 million US dollars in losses in 2001 (4). Commercial cacao production in West Africa and South Asia are not yet affected by WB and FP, but cacao grown in these regions is susceptible to both. With the goal of providing new disease resistant cultivars the USDA-ARS and Mars, Inc. have developed a marker assisted selection (MAS) program. Quantitative trait loci have been identified for resistance to WB, FP, and BP. The potential usefulness of these markers in identifying resistant individuals has been confirmed in an experimental F(1) family in Ecuador.

10.
Health Policy ; 75(2): 131-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15961181

RESUMO

OBJECTIVE: The objective was to determine the factors associated with the use of health care services by the elderly residing in the community. METHODS: A cross-sectional study on 787 elderly people over 64 years of age from Albacete City (Castilla-La Mancha, Spain). The study was carried out by personal home interviews during a 9-month period. The dependent variables were: health care utilization, and characteristics. The independent variables were: self-reported health status, self-reported morbidity, medication use, functional status, mental health, lifestyle habits, social support, and sociodemographic status. RESULTS: The health care services were used by 74.5% in the last 3 months of which 59.4% were general practitioner visits, 18.4% were to nursing staff, and 16.5% were specialist visits. Laboratory tests were performed in 39.2% and radiological examinations in 24.9%. Emergency visits accounted for 2.4%, and hospitalization, 2.9%. Users of health care services among the elderly population were objectively more ill, although there was a group of healthy individuals who also visited the physician and a large group of elderly with considerable health problems who never saw their physician. In the multivariate analysis, general practitioner utilization was independently associated with a perceived unmet need for care (OR = 3.15), a negative self-reported health status (OR = 2.51), and a lower educational level (OR = 2.41). CONCLUSIONS: Subjective factors as perceived need for care, a negative self-reported health status and lower educational level are important factors that influence in the utilization of health care services.


Assuntos
Serviços de Saúde/estatística & dados numéricos , Saúde Pública , Idoso , Comportamento de Escolha , Feminino , Humanos , Entrevistas como Assunto , Masculino , Programas Nacionais de Saúde , Espanha
11.
Biochem Genet ; 40(7-8): 283-92, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12296630

RESUMO

A restriction map has been constructed for Anastrepha suspensa mitochondrial DNA. One HaeIII site was found to be polymorphic among individuals in highly inbred colonies and a feral population. Based on mapping information, the polymorphic site was determined to be in the ATPase 6 gene. Primers TK-J-3804 and C3-N-5460 amplified this region. The amplicon was cut by HaeIII in flies of one haplotype and not cut in flies of the other haplotype. From 30 to 43% of the individual flies studied had this additional HaeIlI site. After cloning of the approximately 5200 bp XbaI fragment, the two mitotypes were identified. A 988 base fragment, coding for the entire tRNA-Lys(AAG), tRNA-Asp(GAC), and ATPase 8genes, and a partial ATPase 6gene was sequenced Four silent mutations, including the one at the informative site were located. The HaeIII polymorphism and other sequence differences may prove useful as a diagnostic for identification of the origin of introduced fruit flies.


Assuntos
DNA Mitocondrial/genética , Tephritidae/genética , Animais , Clonagem Molecular , DNA Mitocondrial/análise , Variação Genética/genética , Endogamia , Polimorfismo de Fragmento de Restrição , Mapeamento por Restrição
12.
J Bacteriol ; 183(18): 5358-63, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11514520

RESUMO

Oleandomycin, a macrolide antibiotic produced by Streptomyces antibioticus, contains two sugars attached to the aglycon: L-oleandrose and D-desosamine. oleY codes for a methyltransferase involved in the biosynthesis of L-oleandrose. This gene was overexpressed in Escherichia coli to form inclusion bodies and in Streptomyces lividans, producing a soluble protein. S. lividans overexpressing oleY was used as a biotransformation host, and it converted the precursor L-olivosyl-erythronolide B into its 3-O-methylated derivative, L-oleandrosyl-erythronolide B. Two other monoglycosylated derivatives were also substrates for the OleY methyltransferase: L-rhamnosyl- and L-mycarosyl-erythronolide B. OleY methyltransferase was purified yielding a 43-kDa single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native enzyme showed a molecular mass of 87 kDa by gel filtration chromatography, indicating that the enzyme acts as a dimer. It showed a narrow pH range for optimal activity, and its activity was clearly stimulated by the presence of several divalent cations, being maximal with Co(2+). The S. antibioticus OleG2 glycosyltransferase is proposed to transfer L-olivose to the oleandolide aglycon, which is then converted into L-oleandrose by the OleY methyltransferase. This represents an alternative route for L-oleandrose biosynthesis from that in the avermectin producer Streptomyces avermitilis, in which L-oleandrose is transferred to the aglycon by a glycosyltransferase.


Assuntos
Antibacterianos/biossíntese , Desoxiaçúcares , Metiltransferases/metabolismo , Oleandomicina/biossíntese , Streptomyces antibioticus/enzimologia , Escherichia coli/enzimologia , Escherichia coli/genética , Hexoses/metabolismo , Metiltransferases/genética , Metiltransferases/isolamento & purificação , Streptomyces/enzimologia , Streptomyces/genética , Streptomyces antibioticus/genética , Streptomyces antibioticus/crescimento & desenvolvimento , Especificidade por Substrato
13.
Electrophoresis ; 22(3): 427-32, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11258750

RESUMO

A specific reverse transcription-polymerase chain reaction (RT-PCR) protocol has been developed for routine detection of avocado sunblotch viroid (ASBVd). Modifications in this diagnostic technique were made to enable fluorescent detection and variant identification using automated capillary electrophoresis (CE) and fluorescent single-strand conformation polymorphism (SSCP) analysis. Sixteen sequence variants characterized in a previous study were analyzed using CE-SSCP on two ABI 310 Genetic Analyzers. Significant differences were detected between data obtained from the two ABI 310 Genetic Analyzers indicating that an internal control must be run concurrently with the samples. The 16 variants could be classified into 11 groups based on the SSCP patterns. The statistical analysis of the migration rate data provided support for the visual differences in SSCP patterns. The use of SSCP in the ASBVd assay is easily accomplished and gives an estimate of the number of variants in crude samples extracted from infected avocado plants.


Assuntos
Corantes Fluorescentes , Variação Genética , Vírus de Plantas/genética , Polimorfismo Conformacional de Fita Simples , Vírus de RNA/genética , RNA Viral/análise , Viroides/genética , Sequência de Bases , DNA Viral , Eletroforese Capilar/métodos , Lauraceae/virologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Arch Esp Urol ; 54(8): 787-95, 2001 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-11816603

RESUMO

OBJECTIVE: To analyze the impact of surgery for bladder cancer on the patient's quality of life. METHODS: The SF-36 questionnaire was utilized to assess the quality of life of 53 cystectomized patients. Sociodemographic data, associated and surgery-related morbidity, type of urinary diversion, anatomopathological stage and current oncological status were analyzed. RESULTS: Patient mean age was 64.3 years. There were 46 males (86.8%), 33 (62.3%) had no schooling, 32 (68.1%) were social class IV and 35 (66.0%) had chronic associated conditions. External urinary diversion had been performed in 28 (52.8%) and bladder substitution in 21 (39.6%) patients. The early complication rate was 37.7% (n = 20) and the late complication rate was 86.8% (n = 46). Tumor stage was < or = pT2 in 28 cases (52.8%). Age correlated inversely with Physical Performance (r = -0.324; p = 0.018). Patients with chronic conditions had a lower score for Physical Performance, Vitality and SFI. Patients with tumor stage < or = pT2 scored higher for Physical Performance (p = 0.034), Vitality (p = 0.046), Mental Health (p = 0.036), Emotional Role (p < 0.05) and MSI (p < 0.05). Those with postoperative complications had a worse score for Physical Performance (p = 0.031), Vitality (p = 0.027), Emotional Role (p = 0.014), Mental Health (p = 0.012) and MSI (p = 0.015). The SF-36 showed no differences between the types of urinary diversion except that patients that had undergone orthotopic bladder substitution had a higher score for Physical Performance (p = 0.014) and FSI (p = 0.045). CONCLUSIONS: Although the quality of life of cystectomized patients is worse than that of the general population, it is better in younger patients without chronic associated conditions, no postoperative complications, lower tumor stage and those submitted to orthotopic bladder substitution.


Assuntos
Qualidade de Vida , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
15.
Qual Life Res ; 10(6): 543-53, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11789554

RESUMO

OBJECTIVES: To assess the quality of life (QoL) of patients on the waiting list for benign prostatic hypertrophy (BPH) surgery and the relationship between prostate symptoms and QoL. MATERIALS AND METHODS: Our study included 189 BPH patients on the waiting list for surgery, during the period from January to December 1999. A survey was conducted to obtain information on sociodemographic characteristics, associated illnesses, prostate symptoms based on the International Prostate Symptoms Score (I-PSS), and QoL based on the 36-item Short Form Health Survey (SF-36). Moreover, the case history, prostate volume measured by ultrasound, and uroflowmetry results were considered. Descriptive, bivariate and multivariate analyses were conducted based on the scores recorded on the SF-36 scales and the other variables. RESULTS: The mean age was 68.8 +/- 6.9 SD. A total of 70.4% of the subjects had other chronic illnesses, 54.1% had severe symptoms (I-PSS > 19), and 69.8% reported that they were extremely dissatisfied with their symptoms. A total of 29.6% of the patients had urethral catheters. The SF-36 scale with the highest scores was social functioning (79.9, 95% CI: 76.5-83.4), whereas the lowest scores referred to role-physical (58.2, 95% CI: 52.3-64.1). Patients with more severe symptoms assigned lower scores to the physical functioning, vitality, social functioning, mental health, role-emotional and mental component summary (MCS) scales. Irritative symptoms were associated with lower vitality, social functioning, mental health and MCS. Patients with urethral catheters recorded lower scores on the physical functioning and role-physical scales. CONCLUSIONS: The QoL of BPH patients on the waiting list for surgery is poorer than that of the general population of the same age. The increased severity of prostate symptoms, particularly the irritative symptoms, leads to a poorer QoL in terms of nearly all aspects of QoL. However, this correlation was not observed for prostate volume nor uroflowmetry data.


Assuntos
Hiperplasia Prostática/fisiopatologia , Hiperplasia Prostática/psicologia , Qualidade de Vida , Perfil de Impacto da Doença , Listas de Espera , Atividades Cotidianas/classificação , Idoso , Estudos Transversais , Humanos , Masculino , Saúde Mental , Dor , Hiperplasia Prostática/cirurgia , Espanha , Inquéritos e Questionários
16.
J Invertebr Pathol ; 76(3): 176-84, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11023745

RESUMO

The cellular response component of body defense in gorgonians and other cnidarians is thought to be carried out by cells with phagocytic capabilities. To test for the phagocytic character of cells, the introduction of foreign particles was employed and observed in both living cells and histological preparations of the gorgonian coral Swiftia exserta. Observations of untreated tissues revealed normal cells and tissue morphologies. A microscopic observation of living cells following the introduction of particles in a cut revealed that only a mixed population of colorless cells phagocytized the particles. Also particles or clumps of particles were seen on the surface of the colorless cells. Subsequent histological observations allowed identity of colorless cells to be inferred as granular amoebocytes, ectodermal cells, and gastrodermal cells. Cells stained for localization of peroxidase (indicative of phagocytic activity) demonstrated the presence of peroxidase-positive cells. Histological preparations revealed that major phagocytosis of particles was associated with tissue trauma. When particles were introduced by means of a cut or inserted thread, phagocytic activity was detected within 2 h. However, it was confined to the granular amoebocytes in the immediate site of trauma. After 24 h, extensive phagocytosis spread throughout a relatively large area surrounding the wound. At that later time, phagocytic cell types included granular amoebocytes, epidermal cells, sclerocytes, mesogleal cells, and gastrodermal cells of the solenia. Observations suggest that trauma induces phagocytosis in cells not normally phagocytic in S. exserta. No localization of phagocytic cells and no mitotic cells were observed at either 2 or 24 h after particle introduction.


Assuntos
Cnidários/fisiologia , Fagocitose/fisiologia , Animais , Cnidários/enzimologia , Peroxidase/análise
17.
Antimicrob Agents Chemother ; 44(5): 1266-75, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10770761

RESUMO

A 9.8-kb DNA region from the oleandomycin gene cluster in Streptomyces antibioticus was cloned. Sequence analysis revealed the presence of 8 open reading frames encoding different enzyme activities involved in the biosynthesis of one of the two 2, 6-deoxysugars attached to the oleandomycin aglycone: L-oleandrose (the oleW, oleV, oleL, and oleU genes) and D-desosamine (the oleNI and oleT genes), or of both (the oleS and oleE genes). A Streptomyces albus strain harboring the oleG2 glycosyltransferase gene integrated into the chromosome was constructed. This strain was transformed with two different plasmid constructs (pOLV and pOLE) containing a set of genes proposed to be required for the biosynthesis of dTDP-L-olivose and dTDP-L-oleandrose, respectively. Incubation of these recombinant strains with the erythromycin aglycon (erythronolide B) gave rise to two new glycosylated compounds, identified as L-3-O-olivosyl- and L-3-O-oleandrosyl-erythronolide B, indicating that pOLV and pOLE encode all enzyme activities required for the biosynthesis of these two 2,6-dideoxysugars. A pathway is proposed for the biosynthesis of these two deoxysugars in S. antibioticus.


Assuntos
Proteínas de Bactérias/genética , Desoxiaçúcares/biossíntese , Hexoses/biossíntese , Streptomyces antibioticus/genética , Sequência de Aminoácidos , Amino Açúcares/biossíntese , Amino Açúcares/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Regulação Bacteriana da Expressão Gênica , Glicosiltransferases/biossíntese , Glicosiltransferases/genética , Dados de Sequência Molecular , Família Multigênica , Oleandomicina/biossíntese , Homologia de Sequência de Aminoácidos , Streptomyces antibioticus/metabolismo
18.
Chem Biol ; 6(12): 845-55, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10631513

RESUMO

BACKGROUND: The biological activity of many microbial products requires the presence of one or more deoxysugar molecules attached to agylcone. This is especially prevalent among polyketides and is an important reason that the antitumor anthracycline antibiotics are avid DNA-binding drugs. The ability to make different deoxyaminosugars and attach them to the same or different aglycones in vivo would facilitate the synthesis of new anthracyclines and the quest for antitumor drugs. This is feasible using the numerous bacterial genes for deoxysugar biosynthesis that are now available. RESULTS: Production of thymidine diphospho (TDP)-L-daunosamine (dnm), the aminodeoxysugar present in the anthracycline antitumor drugs daunorubicin (DNR) and doxorubicin (DXR), and its attachment to epsilon-rhodomycinone to generate rhodomycin D has been achieved by bioconversion with a strain of Streptomyces lividans that bears two plasmids. One contained the Streptomyces peucetius dnmJVUZTQS genes plus dnmW (previously named dpsH and considered to be a polyketide cyclase gene), dnrH, which is not required for the formation of rhodomycin D, and dnrI, a regulatory gene required for expression of the dnm and drr genes. The other plasmid had genes encoding glucose-1-phosphate thymidylyltransferase and TDP-glucose-4,6-dehydratase (dnmL and dnmM, respectively, or mtmDE, their homologs from Streptomyces agrillaceus) plus the drrAB DNR/DXR resistance genes. CONCLUSIONS: The high-yielding glycosylation of the aromatic polyketide epsilon-rhodomycinone using plasmid-borne deoxysugar biosynthesis genes proves that the minimal information for L-daunosamine biosynthesis and attachment in the heterologous host is encoded by the dnmLMJVUTS genes. This is a general approach to making both known and new glycosides of anthracyclines, several of which have medically important antitumor activity.


Assuntos
Antibacterianos/metabolismo , Plasmídeos , Antraciclinas/metabolismo , Genes Bacterianos , Teste de Complementação Genética , Glicosilação , Hexosaminas/genética , Streptomyces/genética
19.
Mol Gen Genet ; 259(3): 299-308, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9749673

RESUMO

A 6-kb region from the chromosome of Streptomyces antibioticus, an oleandomycin producer, was cloned and sequenced. This region was located between the 3' end of the gene encoding the third subunit of the oleandomycin type I polyketide synthase and the oleP and oleB genes, which encode a cytochrome P450 monooxygenase and an oleandomycin resistance gene, respectively. Analysis of the nucleotide sequence revealed the presence of five genes encoding a cytochrome P450-like protein (oleP1), two glycosyltransferases (oleG1 and oleG2) involved in the transfer of the two 6-deoxysugars (L-oleandrose and D-desosamine) to the oleandomycin macrolactone ring, a methyltransferase (oleM1), and a gene (oleY) of unknown function. Insertional inactivation of this region by gene disruption generated an oleandomycin non-producing mutant which accumulated a compound that, according to mass spectrometry analysis, could correspond to the oleandomycin macrolactone ring (oleandolide), suggesting that the mutation affects oleandrosyl glycosyltransferase.


Assuntos
Antibacterianos/biossíntese , Cromossomos Bacterianos/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Oleandomicina/biossíntese , Streptomyces antibioticus/genética , Streptomyces antibioticus/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Bacteriano/genética , Genes Bacterianos , Glicosilação , Metiltransferases/genética , Metiltransferases/metabolismo , Dados de Sequência Molecular , Mutagênese Insercional , Homologia de Sequência de Aminoácidos , Streptomyces antibioticus/enzimologia
20.
Mol Microbiol ; 28(6): 1177-85, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9680207

RESUMO

A 5.2 kb region from the oleandomycin gene cluster in Streptomyces antibioticus located between the oleandomycin polyketide synthase gene and sugar biosynthetic genes was cloned. Sequence analysis revealed the presence of three open reading frames (designated oleI, oleN2 and oleR). The oleI gene product resembled glycosyltransferases involved in macrolide inactivation including the oleD product, a previously described glycosyltransferase from S. antibioticus. The oleN2 gene product showed similarities with different aminotransferases involved in the biosynthesis of 6-deoxyhexoses. The oleR gene product was similar to several glucosidases from different origins. The oleI, oleR and oleD genes were expressed in Streptomyces lividans. OleI and OleD intracellular proteins were partially purified by affinity chromatography in an UDP-glucuronic acid agarose column and OleR was detected as a major band from the culture supernatant. OleI and OleD showed oleandomycin glycosylating activity but they differ in the pattern of substrate specificity: OleI being much more specific for oleandomycin. OleR showed glycosidase activity converting glycosylated oleandomycin into active oleandomycin. A model is proposed integrating these and previously reported results for intracellular inactivation, secretion and extracellular reactivation of oleandomycin.


Assuntos
Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Oleandomicina/metabolismo , Streptomyces antibioticus/enzimologia , Sequência de Aminoácidos , Clonagem Molecular , Cosmídeos/genética , Eletroforese em Gel de Poliacrilamida , Genes Bacterianos , Glicosilação , Glicosiltransferases/isolamento & purificação , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Streptomyces/enzimologia , Streptomyces antibioticus/genética , Especificidade por Substrato
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