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1.
Int J Oral Maxillofac Surg ; 49(2): 237-243, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31285095

ABSTRACT

The aim of this study was to evaluate the possible association between polymorphisms in the catechol-O-methyltransferase (COMT) and ß2-adrenergic receptor (ADRB2) genes and muscular temporomandibular disorders (TMD). This was a case-control study. Individuals were evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders and were divided into three groups: unaffected (no TMD) (n=154); exclusively muscular TMD (n=49); exclusively articular TMD (n=49). Genomic DNA was obtained from saliva samples, and single nucleotide polymorphisms in the COMT (rs165774, rs6269, rs9332377) and ADRB2 (rs2053044, rs1042713, rs1042714) genes were investigated. The TT genotype for the COMT rs9332377 gene was highly associated with the presence of muscular TMD (P= 0.03). With respect to the ADRB2 gene, the non-polymorphic AA genotype in the rs1042713 region was more prevalent in the articular TMD group than in the muscular TMD group (P= 0.05). This study supports the hypothesis that alterations in the COMT and ADRB2 genes influence the muscular pathophysiology.


Subject(s)
Catechol O-Methyltransferase , Temporomandibular Joint Disorders , Brazil , Case-Control Studies , Genotype , Humans , Polymorphism, Single Nucleotide , Receptors, Adrenergic, beta-2
2.
Article in English | MEDLINE | ID: mdl-29133563

ABSTRACT

The search for antiprion compounds has been encouraged by the fact that transmissible spongiform encephalopathies (TSEs) share molecular mechanisms with more prevalent neurodegenerative pathologies, such as Parkinson's and Alzheimer's diseases. Cellular prion protein (PrPC) conversion into protease-resistant forms (protease-resistant PrP [PrPRes] or the scrapie form of PrP [PrPSc]) is a critical step in the development of TSEs and is thus one of the main targets in the screening for antiprion compounds. In this work, three trimethoxychalcones (compounds J1, J8, and J20) and one oxadiazole (compound Y17), previously identified in vitro to be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrPC mRNA levels in N2a cells, as shown by reverse transcription-quantitative real-time PCR. Among them, J8 and Y17 were effective in real-time quaking-induced conversion reactions using rodent recombinant PrP (rPrP) from residues 23 to 231 (rPrP23-231) as the substrate and PrPSc seeds from hamster and human brain. However, when rPrP from residues 90 to 231 (rPrP90-231), which lacks the N-terminal domain, was used as the substrate, only J8 remained effective, indicating that this region is important for Y17 activity, while J8 seems to interact with the PrPC globular domain. J8 also reduced the fibrillation of mouse rPrP23-231 seeded with in vitro-produced fibrils. Furthermore, most of the compounds decreased the amount of PrPC on the N2a cell surface by trapping this protein in the endoplasmic reticulum. On the basis of these results, we hypothesize that J8, a nontoxic compound previously shown to be a promising antiprion agent, may act by different mechanisms, since its efficacy is attributable not only to PrP conversion inhibition but also to a reduction of the PrPC content on the cell surface.


Subject(s)
Chalcones/pharmacology , Drugs, Investigational/pharmacology , Neurons/drug effects , Oxadiazoles/pharmacology , Prion Proteins/antagonists & inhibitors , Animals , Binding Sites , Cell Line, Tumor , Chalcones/chemical synthesis , Cloning, Molecular , Drugs, Investigational/chemical synthesis , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/ultrastructure , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Kinetics , Mice , Molecular Docking Simulation , Neurons/metabolism , Neurons/pathology , Oxadiazoles/chemical synthesis , Prion Proteins/chemistry , Prion Proteins/genetics , Prion Proteins/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Interaction Domains and Motifs , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Structure-Activity Relationship , Thermodynamics
3.
Clin Nutr ESPEN ; 17: 86-91, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28361753

ABSTRACT

INTRODUCTION: Surviving acute kidney (AKI) patients have a higher late mortality compared with those admitted without AKI. The negative impact of malnutrition on the early outcome of AKI patients has recently been confirmed by various studies. However, its impact after hospital discharge has not been studied. The objective of the study was to determine the role of anthropometric measurements and handgrip strength as predictors of mortality 180 days after discharge. METHODOLOGY: Eighty-two survivors AKI patients who were older than 18 y old and followed by AKI team were prospectively evaluated. Patient's characteristics were recorded, anthropometric measurements were taken, handgrip strength (HGS) was measured, subjective global assessment and bioimpedance were applied and blood samples were collected during hospitalization at first and last nephrologist evaluation and in after hospital discharge at 1 month, 3 and 6 months. Multivariable logistic regression was used to adjust confounding and selection bias. RESULTS: Age was 62.3 ± 14.7 years, prevalence of hospitalization in medical wards of 71.6%, index of severity of AKI (ATN-ISS) was 28% and late mortality rates was 25.6%. Risk factors associated with late mortality were the number of comorbidities (HR = 1.79, 95% CI = 1.45-2.46, p = 0.04), cancer (HR = 1.89, 95 CI% = 1.48-3.16, p = 0.01), sepsis (HR = 1.47, 95% CI = 1.18-2.38, p = 0.03), no recovery of renal function at hospital discharge (HR = 1.46, 95% CI = 1.02-2.16, p = 0.03), malnutrition at first evaluation (HR = 1.58, 95% CI = 1.14-2.94, p = 001), the HGS value at the moment of last evaluation by nephrologist (HR = 1.81, 95% CI = 1.17-2.31, p = 0.04) and gain weigh < 1 kg between the moment at first evaluation by nephrologist and one month after hospital discharge (HR = 1.95, 95 CI% = 1.29-3.3, p = 0.02). CONCLUSION: HGS and gain weight were identified as predictors of late mortality. Simple and ease methods can be applied in AKI patients during and after hospitalization to diagnose nutritionally patients who are at higher risk for poor prognosis and, consequently intervention measures can be performed to improve survival in long-term.


Subject(s)
Acute Kidney Injury/diagnosis , Acute Kidney Injury/mortality , Body Weight , Hand Strength , Malnutrition/diagnosis , Malnutrition/mortality , Acute Kidney Injury/physiopathology , Aged , Chi-Square Distribution , Comorbidity , Female , Humans , Logistic Models , Male , Malnutrition/physiopathology , Middle Aged , Multivariate Analysis , Muscle Strength Dynamometer , Nutrition Assessment , Nutritional Status , Patient Discharge , Predictive Value of Tests , Prognosis , Prospective Studies , Risk Factors , Time Factors , Weight Gain
4.
J Urol ; 195(1): 112-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26241906

ABSTRACT

PURPOSE: We prospectively compared buccal mucosa graft and lingual mucosa graft urethroplasty with respect to donor site morbidity and urethroplasty outcome. MATERIALS AND METHODS: Patients treated with buccal mucosa graft (29) or lingual mucosa graft (29) urethroplasty were included in the study. Oral pain and morbidity were assessed using the numeric rating scale (scale 0 to 10) as well as an in-home questionnaire administered 3 days, 2 weeks and 6 months postoperatively. RESULTS: After a mean (± SD) followup of 30 (± 13) months successful urethroplasty was achieved in 24 (82.8%) and 26 (89.7%) patients treated with buccal mucosa graft and lingual mucosa graft, respectively (p = 0.306). Median numeric rating scale after 3 days, 2 weeks and 6 months was 4, 2 and 0 for buccal mucosa graft and 6, 3 and 0 for lingual mucosa graft, respectively, with no statistical differences between the groups. At day 3 significantly more patients in the lingual mucosa graft group had severe difficulties with eating and drinking (62.1% vs 24.1%, p = 0.004) and speaking (93.1% vs 55.2%, p = 0.001), and had dysgeusia (48.3% vs 13.8%, p = 0.01). Two weeks postoperatively speech impairment was still more frequent with lingual mucosa graft (55.2% vs 13.8%, p = 0.002), whereas oral tightness was more frequent with buccal mucosa graft (41.4% vs 6.9%, p = 0.005). After 6 months 44.8% and 31% of patients treated with buccal mucosa graft and lingual mucosa graft, respectively, still reported sensitivity disorders (p = 0.279). CONCLUSIONS: The success of urethroplasty with lingual and buccal mucosa grafts was similar. Oral pain was not different after both grafts. In the early postoperative period there were differences in oral morbidity between buccal and lingual mucosa grafts. Long-term oral morbidity was not infrequent with both grafts.


Subject(s)
Mouth Mucosa/transplantation , Postoperative Complications/etiology , Tissue and Organ Harvesting/adverse effects , Transplant Donor Site/injuries , Urethra/surgery , Urethral Stricture/surgery , Humans , Male , Prospective Studies , Tongue , Treatment Outcome , Urologic Surgical Procedures, Male
5.
J Oral Rehabil ; 42(2): 120-6, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25293389

ABSTRACT

Recent studies showed that patients with chronic TMD pain also feature increased sensitivity in other craniofacial regions, and even in remote peripheral areas, suggesting that nociceptive processing is centrally facilitated in this patient population. The aim of this study was to investigate the existence of a negative correlation between the levels of non-specific physical symptoms and pressure pain thresholds measured by algometry at sites distant from the chief complaint of oro-facial pain in patients with TMD. A total of 20 female patients were evaluated comprising 11 patients diagnosed with myofascial pain (Group I of RDC/TMD) and 9 patients with arthralgia (Group III of RDC/TMD), with both reporting chronic TMD pain for at least 3 months. Patients were tested by the pressure algometry technique, and, in the same visit, clinical diagnosis and levels of non-specific physical symptoms, including pain-related issues or not, were obtained. The raw scores were then standardised into a T-score. The possible correlation between the dependent variable levels of non-specific physical symptoms and pressure pain thresholds measured by algometry at sites distant from the chief complaint of oro-facial pain was assessed with Spearman's correlation coefficient. Results were considered statistically significant, which stood a lower than 5% probability of occurring by chance (P < 0·05). A statistically significant (P = 0·02) negative correlation (-0·51) was found to exist between the levels of non-specific physical symptoms, only if including issues involving pain-related symptoms, and experimental pressure pain thresholds in patients with painful TMD.


Subject(s)
Facial Pain/psychology , Pain Measurement/methods , Pain Threshold/psychology , Somatoform Disorders/physiopathology , Temporomandibular Joint Disorders/physiopathology , Adult , Brazil/epidemiology , Female , Humans , Pressure , Somatoform Disorders/psychology , Surveys and Questionnaires , Temporomandibular Joint Disorders/psychology
6.
Acta Chir Belg ; 114(5): 355-7, 2014.
Article in English | MEDLINE | ID: mdl-26021543

ABSTRACT

We report the case of a 72 year old male with penoscrotal extramammary Paget's disease (EMPD). The patient presented with an eczematous lesion on the scrotum extending on to the base of the penis. Given the persistent and progressive nature of the lesion a biopsy was taken which revealed a malignant lesion suggestive of extramammary Paget's disease. After performing a CAT-scan of the lower abdomen and inguinal region, which was negative, a primary surgical approach with curative intentions was taken. One year after surgery the patient is doing well and shows no sign of local recurrence.


Subject(s)
Paget Disease, Extramammary/diagnosis , Penile Neoplasms/secondary , Plastic Surgery Procedures/methods , Scrotum , Urologic Surgical Procedures, Male/methods , Aged , Humans , Male , Neoplasms, Unknown Primary , Paget Disease, Extramammary/surgery , Penile Neoplasms/diagnosis , Penile Neoplasms/surgery , Penis/pathology , Penis/surgery , Tomography, X-Ray Computed
7.
Int Urol Nephrol ; 45(3): 869-78, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23065432

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50-80 %. Extended daily hemodialysis (EHD) and high volume peritoneal dialysis (HVPD) have emerged as alternative modalities. METHODS: A double-center, randomized, controlled trial was conducted comparing EHD versus HVPD for the treatment for AKI in the intensive care unit (ICU). Four hundred and seven patients were randomized and 143 patients were analyzed. Principal outcome measure was hospital mortality, and secondary end points were recovery of renal function and metabolic and fluid control. RESULTS: There was no difference between the two groups in relation to median ICU stay [11 (5.7-20) vs. 9 (5.7-19)], recovery of kidney function (26.9 vs. 29.6 %, p = 0.11), need for chronic dialysis (9.7 vs. 6.5 %, p = 0.23), and hospital mortality (63.4 vs. 63.9 %, p = 0.94). The groups were different in metabolic and fluid control. Blood urea nitrogen (BUN), creatinine, and bicarbonate levels were stabilized faster in EHD group than in HVPD group. Delivered Kt/V and ultrafiltration were higher in EHD group. Despite randomization, there were significant differences between the groups in some covariates, including age, pre-dialysis BUN, and creatinine levels, biased in favor of the EHD. Using logistic regression to adjust for the imbalances in group assignment, the odds of death associated with HVPD was 1.4 (95 % CI 0.7-2.4, p = 0.19). A detailed investigation of the randomization process failed to explain the marked differences in patient assignment. CONCLUSIONS: Despite faster metabolic control and higher dialysis dose and ultrafiltration with EHD, this study provides no evidence of a survival benefit of EHD compared with HVPD. The limitations of this study were that the results were not presented according to the intention to treat and it did not control other supportive management strategies as nutrition support and timing of dialysis initiation that might influence outcomes in AKI.


Subject(s)
Acute Kidney Injury/therapy , Peritoneal Dialysis/methods , Renal Dialysis/methods , Acute Kidney Injury/metabolism , Acute Kidney Injury/mortality , Aged , Blood Urea Nitrogen , Brazil/epidemiology , Creatinine/metabolism , Female , Follow-Up Studies , Hospital Mortality/trends , Humans , Intensive Care Units , Male , Middle Aged , Retrospective Studies , Treatment Outcome
8.
Braz J Biol ; 69(1): 143-8, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19347157

ABSTRACT

The natural diet of the spiny lobster (Panulirus echinatus) from the São Pedro and São Paulo Archipelago was determined by stomach contents analysis of sixty-eight adult lobsters collected during October 2002, March, July and August 2003. Food items were grouped by gross taxa representing 11 food categories. Analysis included a qualitative (Frequency of Occurrence of item i--FOi) and a quantitative method (Volume of item i--Vi). A Feed Index (FI = FOi x Vi / 100) proposed by Lauzanne (1975) was also used to indicate the importance of each food category (> 50: dominant, 25-50: essential, 10-25: unimportant, < 10: secondary). The most important food category determined by % FOi and % Vi, was fish, followed by crustaceans, green algae, calcareous algae, and rocks. The remaining food categories contributed to less than 30% of FOi and 10% of Vi. Although the Feed Index revealed no dominant food category in the diet of P. echinatus, fish was considered essential, crustaceans unimportant, and the remaining food categories were classified as secondary. According to the analysis, P. echinatus can be properly classified as an omnivorous and a generalist species, because it consumes a great diversity of organisms in several trophic levels. This species presents an opportunistic behaviour, feeding on the prey available at substratum. Future studies should address variations in natural diet related to sex, reproductive cycle, and seasonality.


Subject(s)
Feeding Behavior/physiology , Palinuridae/physiology , Animals , Brazil , Diet/classification , Gastrointestinal Contents , Palinuridae/classification
9.
Braz. j. biol ; 69(1): 143-148, Feb. 2009. ilus, graf, mapas, tab
Article in English | LILACS | ID: lil-510134

ABSTRACT

The natural diet of the spiny lobster (Panulirus echinatus) from the São Pedro and São Paulo Archipelago was determined by stomach contents analysis of sixty-eight adult lobsters collected during October 2002, March, July and August 2003. Food items were grouped by gross taxa representing 11 food categories. Analysis included a qualitative (Frequency of Occurrence of item i - FOi) and a quantitative method (Volume of item i - Vi). A Feed Index (FI = FOi x Vi / 100) proposed by Lauzanne (1975) was also used to indicate the importance of each food category (>50: dominant, 25-50: essential, 10-25: unimportant, <10: secondary). The most important food category determined by percent FOi and percent Vi, was fish, followed by crustaceans, green algae, calcareous algae, and rocks. The remaining food categories contributed to less than 30 percent of FOi and 10 percent of Vi. Although the Feed Index revealed no dominant food category in the diet of P. echinatus, fish was considered essential, crustaceans unimportant, and the remaining food categories were classified as secondary. According to the analysis, P. echinatus can be properly classified as an omnivorous and a generalist species, because it consumes a great diversity of organisms in several trophic levels. This species presents an opportunistic behaviour, feeding on the prey available at substratum. Future studies should address variations in natural diet related to sex, reproductive cycle, and seasonality.


A dieta alimentar da lagosta espinhosa, Panulirus echinatus, do Arquipélago São Pedro e São Paulo foi determinada a partir da análise de conteúdo estomacal de sessenta e oito espécimes adultos, coletados em outubro de 2002, março, julho e agosto de 2003. Os itens alimentares foram agrupados em grandes taxa, representando 11 categorias. As análises incluíram um procedimento qualitativo (Freqüência de Ocorrência do item i - FOi) e um método quantitativo (Volume do item i - Vi). Também foi utilizado o Índice Alimentar (IA= FOi x Vi / 100) proposto por Lauzanne (1975) para indicar a importância de cada categoria (>50: dominante, 25-50: essencial, 10-25: não-importante, <10: secundário). A categoria alimentar mais importante determinada pela FOi e Vi foi peixe, seguida de crustáceos, alga verde, alga calcária e rochas. As categorias alimentares restantes contribuíram com menos de 30 por cento da FOi e 10 por cento do Vi. Embora o Índice Alimentar não tenha revelado nenhum item dominante na dieta alimentar de P. echinatus, a categoria peixe foi considerada como essencial, crustáceos como não-importante e as categorias restantes foram classificadas como secundárias. De acordo com as análises, P. echinatus pode ser corretamente classificada como sendo uma espécie onívora e generalista, uma vez que se alimenta de uma grande diversidade de organismos em diferentes níveis tróficos. Esta espécie apresenta um comportamento oportunista, alimentando-se principalmente de presas disponíveis no substrato. Para estudos futuros, recomenda-se que sejam realizadas análises considerando variações da dieta alimentar associada ao sexo, ao ciclo reprodutivo e à sazonalidade.


Subject(s)
Animals , Feeding Behavior/physiology , Palinuridae/physiology , Brazil , Diet/classification , Gastrointestinal Contents , Palinuridae/classification
10.
J Digit Imaging ; 14(2 Suppl 1): 217-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11442102

ABSTRACT

Clustered microcalcifications, which are frequently an important signal of possible cancer, are usually hidden in dense breast images, adding more difficulty in mammogram medical analysis. In this work we evaluate the performance of a previously developed computer-aided detection scheme, modified for application to dense breast images. The main focus of this investigation was on the effect of different contrast resolutions on the processing performance. We have processed dense breast images digitized with 8 and 12 bits to evaluate the performance of this computer-aided detection scheme with different contrast resolutions. As expected, for most of the 12-bit images, the number of detected signals was greater or at least equal to that of the 8-bit images.


Subject(s)
Calcinosis/diagnostic imaging , Mammography/methods , Radiographic Image Enhancement , Female , Humans
11.
J Pediatr ; 129(5): 711-7, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8917238

ABSTRACT

OBJECTIVES: To determine the cause of increased central venous catheter-associated (CVC) bloodstream infection (BSI) rates in a cohort of pediatric hematology /oncology patients receiving home health care (HHC). METHODS: A retrospective cohort study of hematology/oncology patients with CVCs receiving HHC from January 1992 through November 1994. RESULTS: Of 182 patients with CVCs identified during the study period, 58 (32%) acquired 90 BSIs during 75,085 CVC days. BSI rates increased significantly from 1992 through 1994 (0.8 vs 1.0 vs 1.7 BSIs per 1000 CVC days; p < 0.005). Known risk factors, including catheter type, patient age less than 5 years, sex, or diagnosis, were not associated with increased BSI rates. After introduction of needleless devices for CVC access to the HHC regimen in May 1993, BSI rates increased 80% (from 0.81 to 1.46 BSIs/1000 CVC days, relative risk 1.8; p < 0.02). The only other significant risk factor was the race of the patient. White children had the lowest BSI rate before and after needleless-device introduction (0.4 vs 0.9 BSIs/1000 CVC days; p > 0.1), whereas black patients had the highest, unaffected by the introduction of these devices (2.5 BSIs/1000 CVC days). Both Hispanic (0.5 vs 1.6 BSIs/1000 CVC days) and Asian-American children's (0.4 vs 1.5 BSIs/1000 CVC days) BSI rates increased threefold and fourfold after the introduction of needleless devices. CONCLUSIONS: Our data suggest that pediatric hematology/oncology patients receiving HHC via needleless devices may have an increased risk of BSIs, and this risk may vary by race. We hypothesize that prevention of BSIs may require consideration of cultural, ethnic, and language differences when parents are trained to provide care for their children with CVCs in the home.


Subject(s)
Catheterization, Central Venous/adverse effects , Racial Groups , Sepsis/etiology , Adolescent , Adult , Catheters, Indwelling/adverse effects , Child , Child, Preschool , Female , Hematologic Diseases/drug therapy , Humans , Infant , Male , Needles , Neoplasms/drug therapy , Retrospective Studies , Risk Factors , Severity of Illness Index , Time Factors
12.
Braz J Med Biol Res ; 27(6): 1291-7, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7894342

ABSTRACT

1. Outer-membrane protein patterns of Escherichia coli recovered from the peritoneal cavities of infected guinea pigs and grown in medium M9 containing 2,2'-dipyridyl were studied by polyacrylamide gel electrophoresis (SDS-PAGE) to determine whether in vivo conditions of growth affected the expression of these bacterial surface proteins. 2. Eleven strains of septicemic E. coli studied in vitro under conditions of iron restriction expressed iron-regulated outer-membrane proteins, mainly the protein of approximately 74 kDa, whereas avirulent strains grown under similar conditions did not present the 74-kDa protein. 3. These results show the distribution of iron-regulated outer-membrane proteins among avian E. coli and suggest that the protein of approximately 74 kDa may be important for the virulence of these strains.


Subject(s)
Bacterial Outer Membrane Proteins/physiology , Escherichia coli/physiology , Iron/physiology , 2,2'-Dipyridyl , Animals , Chickens , Electrophoresis, Polyacrylamide Gel , Escherichia coli/growth & development , Escherichia coli/pathogenicity , Guinea Pigs
13.
Braz. j. med. biol. res ; 27(6): 1291-1297, June 1994.
Article in English | LILACS | ID: lil-319775

ABSTRACT

1. Outer-membrane protein patterns of Escherichia coli recovered from the peritoneal cavities of infected guinea pigs and grown in medium M9 containing 2,2'-dipyridyl were studied by polyacrylamide gel electrophoresis (SDS-PAGE) to determine whether in vivo conditions of growth affected the expression of these bacterial surface proteins. 2. Eleven strains of septicemic E. coli studied in vitro under conditions of iron restriction expressed iron-regulated outer-membrane proteins, mainly the protein of approximately 74 kDa, whereas avirulent strains grown under similar conditions did not present the 74-kDa protein. 3. These results show the distribution of iron-regulated outer-membrane proteins among avian E. coli and suggest that the protein of approximately 74 kDa may be important for the virulence of these strains.


Subject(s)
Animals , Guinea Pigs , Escherichia coli , Iron , Bacterial Outer Membrane Proteins/physiology , 2,2'-Dipyridyl , Chickens , Electrophoresis, Polyacrylamide Gel , Escherichia coli
14.
Braz J Med Biol Res ; 26(3): 261-75, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8257927

ABSTRACT

1. We cloned the aerobactin region and its receptor from pMV14, a large nonconjugative plasmid isolated from the virulent strain UEL14, to assess the importance of the aerobactin iron uptake system as a virulence determinant in septicemic avian Escherichia coli. 2. The physical map of the region of the recombinant plasmid (pGMV1) containing the genes for synthesis of aerobactin and its receptor was very similar to the corresponding region in pABN1 containing the genetic determinants for the aerobactin system of pColV-K30. 3. The 74-kDa outer-membrane protein encoded by pGMV1 cross-reacted immunologically with the 74-kDa aerobactin receptor protein encoded by pABN1. 4. Various avirulent E. coli strains carrying the recombinant plasmid, which contains only the aerobactin system, were assayed for virulence and were found to be avirulent for chickens. Only the wild-type aerobactin-producing strain was virulent in a pathogenicity test for chickens. 5. These results show that the aerobactin system by itself does not confer virulence, and that other factors are necessary for virulence of avian strains of E. coli.


Subject(s)
Escherichia coli/pathogenicity , Hydroxamic Acids/metabolism , Transformation, Bacterial , Animals , Bacterial Outer Membrane Proteins/analysis , Blotting, Southern , Chickens , Cloning, Molecular , DNA Probes , Electrophoresis, Polyacrylamide Gel , Escherichia coli/genetics , Escherichia coli/metabolism , Plasmids/isolation & purification , Virulence
15.
Braz. j. med. biol. res ; 26(3): 261-75, Mar. 1993. ilus, tab
Article in English | LILACS | ID: lil-148691

ABSTRACT

1. We cloned the aerobactin region and its receptor from pMV14, a large nonconjugative plasmid isolated from the virulent strain UEL14, to assess the importance of the aerobactin iron uptake system as a virulence determinant in septicemic avian Escherichia coli. 2. The physical map of the region of the recombinant plasmid (pGMV1) containing the genes for synthesis of aerobactin and its receptor was very similar to the corresponding region in pABN1 containing the genetic determinants for the aerobactin system of pColV-K30. 3. The 74-kDa outer-membrane protein encoded by pGMV1 cross-reacted immunologically with the 74-kDa aerobactin receptor protein encoded by pABN1. 4. Various avirulent E. coli strains carrying the recombinant plasmid, which contains only the aerobactin system, were assayed for virulence and were found to be avirulent for chickens. Only the wild-type aerobactin-producing strain was virulent in a pathogenicity test for chickens. 5. These results show that the aerobactin system by itself does not confer virulence, and that other factors are necessary for virulence of avian strains of E. coli


Subject(s)
Animals , Hydroxamic Acids/metabolism , Escherichia coli/pathogenicity , Transformation, Bacterial , Blotting, Southern , Chickens , Cloning, Molecular , DNA Probes , Electrophoresis, Polyacrylamide Gel , Escherichia coli/genetics , Escherichia coli/metabolism , Plasmids/isolation & purification , Bacterial Outer Membrane Proteins/analysis , Virulence
17.
Braz J Med Biol Res ; 24(7): 677-85, 1991.
Article in English | MEDLINE | ID: mdl-1823285

ABSTRACT

1. Strains of avian septicemic E. coli were examined for association among the determinants of drug resistance, the genes for aerobactin production and virulence. 2. In conjugation experiments, a single plasmid (100 Md) from a strain of septicemic E. coli (UEL 29) transferred to E. coli K12 pathogenicity for 1-day old chicks plus resistance to streptomycin and the ability to produce aerobactin and colicin. 3. Additional evidence for the association of R-plasmid and the production of aerobactin, colicin, resistance to sulfadiazine and pathogenicity was obtained by disassociation when all traits were lost simultaneously. 4. These data provide additional evidence for the importance of the aerobactin system for the pathogenicity of avian E. coli.


Subject(s)
Chickens , Escherichia coli/pathogenicity , Hydroxamic Acids/metabolism , Plasmids/genetics , Animals , Colicins/biosynthesis , Drug Resistance, Microbial/genetics , Escherichia coli/genetics , Genes, Bacterial , R Factors , Streptomycin , Sulfadiazine , Virulence/genetics
18.
Braz. j. med. biol. res ; 24(7): 677-85, 1991. tab
Article in English | LILACS | ID: lil-99503

ABSTRACT

Strain of avian septicemic E. coli were examined for association among the determinants of drug resistance, the genes for aerobactin production and virulence. In conjugation experiments, a single plasmid (100 Md) from a strain of septicemic E. coli (UEL 29) transferred to E. coli K12 pathogenicity for 1-day old chicks plus resistance to streptomycin and the ability to produce aerobactin and colicin. Additional evidence for the association of R-plasmid and the production of aerobactin, colicin, resistance to sulfadiazine and pathogenicity was obtained by disassociation when all traits were lost simultaneously. These data provide additional evidence for the importance of the aerobactin system for the pathogenicity of avian E. coli


Subject(s)
Animals , Chickens , Escherichia coli Infections/veterinary , Escherichia coli/pathogenicity , Genetic Code , Hydroxamic Acids/metabolism , Plasmids , Poultry Diseases/microbiology , Sepsis/veterinary , Colicins/biosynthesis , DNA, Bacterial/analysis , Drug Resistance, Microbial/genetics , Electrophoresis, Agar Gel , Escherichia coli Infections/microbiology , Escherichia coli/genetics , Genes, Bacterial , Molecular Weight , R Factors , Sepsis/microbiology , Streptomycin , Sulfadiazine , Virulence
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