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1.
BMC Genomics ; 24(1): 680, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957547

RESUMO

BACKGROUND: In dairy cows, diet is one factor that can affect their milk production and composition. However, the effect of feed restriction on milk miRNome has not yet been described. Indeed, milk is the body fluid with the highest RNA concentration, which includes numerous microRNA. Its presence in the four different milk fractions, whole milk, fat globules, mammary epithelial cells and extracellular vesicles, is still poorly documented. This study aimed to describe the effects of different feed restrictions on the miRNome composition of different milk fractions. RESULTS: Two feed restrictions were applied to lactating dairy cows, one of high intensity and one of moderate intensity. 2,896 mature microRNA were identified in the different milk fractions studied, including 1,493 that were already known in the bovine species. Among the 1,096 microRNA that were sufficiently abundant to be informative, the abundance of 1,027 of them varied between fractions: 36 of those were exclusive to one milk fraction. Feed restriction affected the abundance of 155 microRNA, with whole milk and milk extracellular vesicles being the most affected, whereas milk fat globules and exfoliated mammary epithelial cells were little or not affected at all. The high intensity feed restriction led to more microRNA variations in milk than moderate restriction. The target prediction of known microRNA that varied under feed restriction suggested the modification of some key pathways for lactation related to milk fat and protein metabolisms, cell cycle, and stress responses. CONCLUSIONS: This study highlighted that the miRNome of each milk fraction is specific, with mostly the same microRNA composition but with variations in abundance between fractions. These specific miRNomes were affected differently by feed restrictions, the intensity of which appeared to be a major factor modulating milk miRNomes. These findings offer opportunities for future research on the use of milk miRNA as biomarkers of energy status in dairy cows, which is affected by feed restrictions.


Assuntos
Líquidos Corporais , MicroRNAs , Feminino , Bovinos , Animais , Lactação , Leite/metabolismo , Dieta/veterinária , MicroRNAs/genética , MicroRNAs/metabolismo , Ração Animal/análise
2.
Epigenetics ; 18(1): 2215633, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37302099

RESUMO

Mastitis is among the main reasons women cease breastfeeding, which leads to them supplementing breast milk with artificial formula. In farm animals, mastitis results in significant economic losses and the premature culling of some animals. Nevertheless, researchers do not know enough about the effect of inflammation on the mammary gland. This article discusses the changes to DNA methylation in mouse mammary tissue caused by lipopolysaccharide-induced inflammation (4 h post-injection of lipopolysaccharide). We analysed the expression of some genes related to mammary gland function, epigenetic regulation, and the immune response. The analysis focused on three comparisons: inflammation during the first lactation, inflammation during second lactation with no history of inflammation, and inflammation during second lactation with previous inflammation. We identified differentially methylated cytosines (DMCs), differentially methylated regions (DMRs), and some differentially expressed genes (DEGs) for each comparison. The three comparisons shared some DEGs; however, few DMCs and only one DMR were shared. These observations suggest that inflammation is one of several factors affecting epigenetic regulation during successive lactations. Furthermore, the comparison between animals in second lactation with and without inflammation, with no inflammation history during first lactation showed a different pattern compared to the other conditions in this experiment. This indicates that inflammation history plays an important role in determining epigenetic changes. The data presented in this study suggest that lactation rank and previous inflammation history are equally important when explaining mammary tissue gene expression and DNA methylation changes.Abbreviations: RRBS, reduced representation bisulfite sequencing; RT-qPCR, real-time quantitative polymerase chain reaction; MEC, mammary epithelial cells; TSS, transcription start site; TTS, transcription termination site; UTR, untranslated region; SINE, short interspersed nuclear element; LINE, long interspersed nuclear element; CGI, CpG island; DEG, differentially expressed gene; DMC, differentially methylated cytosine; DMR, differentially methylated region; GO term, gene ontology term; MF, molecular function; BP, biological process.


Assuntos
Metilação de DNA , Mastite , Humanos , Feminino , Camundongos , Animais , Epigênese Genética , Lipopolissacarídeos/toxicidade , Lactação/genética , Mastite/genética , Expressão Gênica
3.
Epigenetics ; 18(1): 2215620, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37219968

RESUMO

Mastitis is among the main reasons women cease breastfeeding. In farm animals, mastitis results in significant economic losses and the premature culling of some animals. Nevertheless, the effect of inflammation on the mammary gland is not completely understood. This article discusses the changes to DNA methylation in mouse mammary tissue caused by lipopolysaccharide-induced inflammation after in vivo intramammary challenges and the differences in DNA methylation between 1st and 2nd lactations. Lactation rank induces 981 differential methylations of cytosines (DMCs) in mammary tissue. Inflammation in 1st lactation compared to inflammation in 2nd lactation results in the identification of 964 DMCs. When comparing inflammation in 1st vs. 2nd lactations with previous inflammation history, 2590 DMCs were identified. Moreover, Fluidigm PCR data show changes in the expression of several genes related to mammary function, epigenetic regulation, and the immune response. We show that the epigenetic regulation of two successive physiological lactations is not the same in terms of DNA methylation and that the effect of lactation rank on DNA methylation is stronger than that of the onset of inflammation. The conditions presented here show that few DMCs are shared between comparisons, suggesting a specific epigenetic response depending on lactation rank, the presence of inflammation, and even whether the cells had previously suffered inflammation. In the long term, this information could lead to a better understanding of the epigenetic regulation of lactation in both physiological and pathological conditions.Abbreviations: RRBS, reduced representation bisulphite sequencing; RT-qPCR, real-time quantitative polymerase chain reaction; MEC, mammary epithelial cells; MaSC, mammary stem cell; TSS, transcription start site; TTS, transcription termination site; UTR, untranslated region; SINE, short interspersed nuclear element; LINE, long interspersed nuclear element; CGI, CpG island; DEG, differentially expressed gene; DMC, differentially methylated cytosine; DMR, differentially methylated region; GO term, gene ontology term; MF, molecular function; BP, biological process.


Assuntos
Metilação de DNA , Mastite , Feminino , Animais , Camundongos , Humanos , Epigênese Genética , Lactação , Inflamação , Citosina , Expressão Gênica
4.
Sci Rep ; 12(1): 18886, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344510

RESUMO

Milk production in dairy cows is affected by numerous factors, including diet. Feed restriction is known to have little impact on milk total protein content but its effect on the fine protein composition is still poorly documented. The objective of this study was to describe the effects of two feed restriction trials of different intensities on the milk protein composition of Holstein cows. One restriction trial was of high intensity (H: 8 mid-lactation Holstein cows) and the second of moderate intensity (M: 19 peak lactation Holstein cows). Feed restriction decreased the milk protein yield for caseins under the M trial and of all six major milk proteins under the H trial. These decreased yields lead to lower concentrations of αs1-, αs2- and ß-caseins during the H trial. The milk proteome, analyzed on 32 milk samples, was affected as a function of restriction intensity. Among the 345 proteins identified eight varied under the M trial and 160 under the H trial. Ontology analyses revealed their implication in carbohydrate, lipid and protein metabolisms as well as in the immune system. These proteins reflected adaptations of the animal and mammary gland physiology to feed restriction and constituted a signature of this change.


Assuntos
Lactação , Proteínas do Leite , Animais , Bovinos , Feminino , Ração Animal/análise , Caseínas/metabolismo , Dieta/veterinária , Lactação/fisiologia , Leite/química , Proteínas do Leite/metabolismo
5.
BMC Genomics ; 20(1): 621, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362707

RESUMO

BACKGROUND: Genetic polymorphisms are known to influence milk production and composition. However, the genomic mechanisms involved in the genetic regulation of milk component synthesis are not completely understood. MicroRNAs (miRNAs) regulate gene expression. Previous research suggests that the high developmental potential of the mammary gland may depend in part on a specific miRNA expression pattern. The objective of the present study was to compare the mammary gland miRNomes of two dairy cow breeds, Holstein and Montbéliarde, which have different mammogenic potentials that are related to differences in dairy performance. RESULTS: Milk, fat, protein, and lactose yields were lower in Montbéliarde cows than in Holstein cows. We detected 754 distinct miRNAs in the mammary glands of Holstein (n = 5) and Montbéliarde (n = 6) midlactating cows using RNA-Seq technology, among which 738 were known and 16 were predicted miRNAs. The 25 most abundant miRNAs accounted for 90.6% of the total reads. The comparison of their abundances in the mammary glands of Holstein versus Montbéliarde cows identified 22 differentially expressed miRNAs (Padj ≤ 0.05). Among them, 11 presented a fold change ≥2, and 2 (miR-100 and miR-146b) were highly expressed. Among the most abundant miRNAs, miR-186 is known to inhibit cell proliferation and epithelial-to-mesenchymal transition. Data mining showed that 17 differentially expressed miRNAs with more than 20 reads were involved in the regulation of mammary gland plasticity. Several of them may potentially target mRNAs involved in signaling pathways (such as mTOR) and lipid metabolism, thereby indicating that they could influence milk composition. CONCLUSION: We found differences in the mammary gland miRNomes of two dairy cattle breeds. These differences suggest a potential role for miRNAs in mammary gland plasticity and milk component synthesis, both of which are related to milk production and composition. Further research is warranted on the genetic regulation of miRNAs and their role in milk synthesis.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Lactação/genética , Glândulas Mamárias Animais/metabolismo , MicroRNAs/genética , RNA-Seq , Animais , Bovinos , Feminino , Perfilação da Expressão Gênica , Leite/química , Leite/metabolismo
6.
Sci Rep ; 9(1): 20345, 2019 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-31889100

RESUMO

The concept of milk as a healthy food has opened the way for studies on milk components, from nutrients to microRNAs, molecules with broad regulatory properties present in large quantities in milk. Characterization of these components has been performed in several species, such as humans and bovine, depending on the stages of lactation. Here, we have studied the variation in milk microRNA composition according to genetic background. Using high throughput sequencing, we have characterized and compared the milk miRNomes of Holstein and Normande cattle, dairy breeds with distinct milk production features, in order to highlight microRNAs that are essential for regulation of the lactation process. In Holstein and Normande milk, 2,038 and 2,030 microRNAs were identified, respectively, with 1,771 common microRNAs, of which 1,049 were annotated and 722 were predicted. The comparison of the milk miRNomes of two breeds allowed to highlight 182 microRNAs displaying significant differences in the abundance. They are involved in the regulation of lipid metabolism and mammary morphogenesis and development, which affects lactation. Our results provide new insights into the regulation of molecular mechanisms involved in milk production.


Assuntos
MicroRNAs , Leite , Transcriptoma , Fatores Etários , Animais , Cruzamento , Bovinos , Biologia Computacional/métodos , Patrimônio Genético , Sequenciamento de Nucleotídeos em Larga Escala , Leite/metabolismo , Especificidade da Espécie
7.
J Dairy Sci ; 94(5): 2418-24, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21524533

RESUMO

α-Lactalbumin (Alac) is one of the major milk proteins. Its gene expression is restricted to epithelial cells of the lactating mammary gland. The Alac interaction with a uridine 5'-diphosphate-galactosyltransferase induces lactose synthesis, a major osmotic regulator of milk secretion. Other functions attributed to this protein include induction of apoptosis and anti-inflammatory activities. To assess if forced expression of this gene during early gestation or involution could affect mammary physiology, an Alac-encoding minigene was expressed in transgenic mice under the transcriptional regulation of the mouse mammary tumor virus promoter. The mammary expression did not interfere with gestation, resulted in a slight increase in milk yield as indirectly assessed by the 11% increased growth rate of the pups reared by transgenic females compared with that of those reared by control mice, and induced a slight delay in the early involution process, as demonstrated by histological analyses. The use of the mouse mammary tumor virus promoter resulted in Alac expression in several nonmammary tissues, such as the brain, the testis, the ovary, and the uterus. Although it did not affect male reproductive performances, it induced a female subfertile phenotype, characterized by embryonic implantation failure in the transgenic female reproductive tract.


Assuntos
Fertilidade , Lactalbumina/metabolismo , Lactação/fisiologia , Vírus do Tumor Mamário do Camundongo/genética , Regiões Promotoras Genéticas , Animais , Feminino , Expressão Gênica , Lactalbumina/genética , Masculino , Glândulas Mamárias Animais/metabolismo , Camundongos , Camundongos Transgênicos
8.
Am J Transplant ; 8(8): 1694-701, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18557729

RESUMO

Mutations in one or more genes encoding complement-regulatory proteins predispose to atypical hemolytic uremic syndrome (aHUS) and its recurrence following kidney transplantation. We evaluated plasma complement level and performed a screening for mutations in genes encoding complement Factors H and I (CFH, CFI) and membrane cofactor protein (MCP) in 24 kidney transplant recipients experiencing de novo thrombotic microangiopathy (TMA). Six patients presented with low C3 and/or low Factor B levels suggestive complement alternative pathway. A mutation in the CFH or CFI gene was found in 7/24 patients (29%), two of whom had a mutation in both genes. On the contrary, no mutation was identified in a control kidney transplant patients group (n = 25) without TMA. Patients with or without mutations were similar with regard to clinical features. Eight out of 24 patients lost their graft within 1 year of posttransplantation including six patients with a CFH mutation or a decrease of C3 or CFB in plasma. To conclude, kidney transplant patients with de novo TMA exhibit an unexpectedly high frequency of CFH and CFI mutations. These results suggest that genetic abnormalities may represent risk factors for de novo TMA after kidney transplantation and raise the question of the best therapeutic strategy.


Assuntos
Fator I do Complemento/genética , Transplante de Rim/efeitos adversos , Rim/irrigação sanguínea , Proteína Cofatora de Membrana/genética , Adulto , Fator H do Complemento/genética , Feminino , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Mutação , Estudos Retrospectivos , Fatores de Risco , Trombose
9.
Dev Dyn ; 236(3): 836-42, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17226816

RESUMO

Expression of the goat prion protein gene locus was assessed by reverse transcriptase-polymerase chain reaction on testes and ovaries at various developmental stages. A weak and stochastic expression of the PRNP and PRNT genes was observed. For PRNT, it is consistent with the detected deletions of two single nucleotides within its open reading frame in ruminant genes. PRND was expressed in both tissues at all stages. Whereas its expression is constant in the ovaries, it increases in testes between 36 and 46 days postcoitum (dpc) and remains high thereafter. In testes, Doppel was found in the nucleus of germinal cells and in the cytoplasm of Leydig cells at 44 dpc. It was detected in the cytoplasm of Leydig cells and of some Sertoli and germinal cells at 62 dpc. In the ovaries, it was observed in the nucleus of germinal cells at 44 dpc and mainly in their cytoplasm at 62 dpc. This expression pattern was shown to parallel that of C-kit and suggests Doppel involvement in early testis differentiation.


Assuntos
Perfilação da Expressão Gênica , Cabras/genética , Príons/genética , Diferenciação Sexual/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Cabras/embriologia , Humanos , Imuno-Histoquímica , Masculino , Dados de Sequência Molecular , Ovário/química , Ovário/embriologia , Ovário/metabolismo , Gravidez , Príons/metabolismo , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA , Testículo/química , Testículo/embriologia , Testículo/metabolismo
10.
J Physiol Pharmacol ; 56 Suppl 3: 215-24, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16077204

RESUMO

cDNA arrays have proven to be useful tools to screen gene expression in many animal species including livestock species. A collaborative program was launched to construct a ruminant cDNA collection, representative of three tissues: Muscle, Embryo and Mammary gland, named MEM. This collection gathers clones mainly arising from 3 non-normalised cDNA libraries: a directed bovine muscle library, a 14-day-old bovine embryo library and a goat lactating mammary library. It is made up of 1896 clones (637 muscle, 882 embryo and 377 mammary cDNAs), selected after sequencing and bioinformatic analyses. Amplification products yielded from these clones as well as controls were printed onto Nylon membranes to generate macroarrays. Hybridisation with relevant cDNA targets allowed checking the location of about 50 cDNAs and the specificity of each sub-set of the repertoire. Macroarrays were hybridised with radiolabelled cDNA complex targets from five different tissues (muscle, embryo, mammary gland, adipose tissue and oocyte). Both somatic and germinal complex targets gave valid hybridisation signals with 45 to 80% of the printed probes. This specific cDNA collection now provides a powerful tool for transcriptomic studies with the ultimate objective to better understand physiological and metabolic functions in ruminants. It will be subsequently included into a forthcoming larger collection.


Assuntos
Perfilação da Expressão Gênica/métodos , Carne , Proteínas do Leite/genética , Proteínas Musculares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Reprodução/genética , Ruminantes/genética , Animais , Bovinos/genética , Sondas de DNA , Bases de Dados Genéticas , Embrião de Mamíferos/química , Feminino , Biblioteca Gênica , Cabras/genética , Masculino , Glândulas Mamárias Animais/química , Músculo Esquelético/química , RNA/análise , Reprodutibilidade dos Testes , Ovinos/genética , Transcrição Gênica
11.
Diabetes Metab ; 30(5): 417-23, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15671909

RESUMO

OBJECTIVE: Since the Edmonton protocol, islet transplantation (IT) offers the prospect of adequate glycemic control with no major surgical risk. In our single-center experience of IT, we studied the recruitment of eligible diabetic patients. METHODS: Between 1998 and 2002, we screened 79 diabetic patients that were divided into 2 groups according to their renal status: 41 were not receiving dialysis (ND) while 38 were receiving ongoing dialysis (D). RESULTS: In the ND group, 20 patients initiated the contact with our team, 8 patients were recruited during hospitalization for very poor glycemic imbalance, and 13 were referred by their diabetologist. 14/41 (34%) patients were ineligible for IT either because of very good glycemic balance, detectable C-peptide (C-p), kidney or liver problems, or plans for future pregnancy. 16/41 (39%) did not wish to proceed, 7 of whom were more interested by a pump. 11/41 (27%) were eligible, among which 8 are currently being assessed, 1 is on the waiting list and 2 have been transplanted. In the D group, 17/38 (45%) had a detectable C-p and received a kidney graft alone. Among the remaining 21 C-p negative diabetic patients, 3 were not eligible for kidney transplantation mainly for psychological reasons, and 4 were enlisted for kidney+pancreas transplantation. The remaining 14 C-p negative patients were kidney-transplanted. Among them, 6 were not eligible for IT, mainly for lack of motivation, slightly positive C-p stimulation tests, obesity, cancer, or increased creatininemia. The remaining 8/14 C-p negative kidney-engrafted patients were enlisted for IT. 3 had secondary failure with the pre-Edmonton immunosuppressive (IS) protocol. Five have been transplanted with the Edmonton-like IS regimen. CONCLUSION: Twenty-five per cent of the 79 patients for whom islet transplantation was considered underwent pregraft assessment and 12% (10 patients, 8 kidney-transplanted and 2 islet alone) of the 79 have been transplanted. The main eligibility criteria were undetectable Cpeptide, normal kidney function, average weight, glycemic imbalance, hypoglycemia unawareness, and glycemic brittleness.


Assuntos
Diabetes Mellitus Tipo 1/cirurgia , Diabetes Mellitus Tipo 2/cirurgia , Transplante das Ilhotas Pancreáticas/estatística & dados numéricos , Seleção de Pacientes , Adulto , Biomarcadores/sangue , Glicemia/metabolismo , Índice de Massa Corporal , Peptídeo C/sangue , Nefropatias Diabéticas/cirurgia , Feminino , Humanos , Falência Renal Crônica/cirurgia , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal/estatística & dados numéricos , Estudos Retrospectivos , Resultado do Tratamento
12.
Eur J Epidemiol ; 17(11): 1019-22, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12380715

RESUMO

During a 5-year period, from 1993 to 1997, nocardial infection was diagnosed in 26 patients admitted to hospitals in 11 cities in Italy. Pathogens were identified as Nocardia asteroides in 18 cases, as N. farcinica in five cases, as N. nova in two and as N. brasiliensis in one case. All cases were difficult to diagnose, as usually it happens with this disease: physicians have to be alert to suspect nocardial infection so that appropriate therapy can be early given. This is the second retrospective report on Nocardia spp. infection conducted in Italy, suggesting the utility to organise a permanent network for a national survey system for nocardiosis.


Assuntos
Nocardiose/epidemiologia , Resistência Microbiana a Medicamentos , Humanos , Itália/epidemiologia , Testes de Sensibilidade Microbiana , Nocardia/classificação , Nocardia/efeitos dos fármacos , Nocardia/isolamento & purificação , Nocardiose/diagnóstico , Nocardiose/tratamento farmacológico , Nocardiose/microbiologia , Estudos Retrospectivos , Especificidade da Espécie
13.
Lett Appl Microbiol ; 31(5): 400-3, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11069645

RESUMO

AIMS: The present study describes a system based on PCR and restriction endonuclease analysis (REA) to distinguish the seven currently recognized Malassezia species. METHODS AND RESULTS: Fifty-five representative yeast isolates were examined. A single primer pair was designed to amplify the large subunit ribosomal RNA (LSU rRNA) gene of the seven Malassezia species, and identification was achieved by digestion of the PCR products with three restriction endonucleases: BanI, HaeII and MspI. A specific restriction endonuclease analysis pattern was determined for each species investigated. Moreover, PCR-REA allowed the detection and characterization of mixtures of several Malassezia species. CONCLUSION: PCR-REA of only the LSU rRNA gene is a reliable and rapid method to distinguish all Malassezia species. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR-REA represents a considerable saving in time over currently available identification procedures. This method should be evaluated on clinical material directly.


Assuntos
Malassezia/classificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Desoxirribonuclease HpaII/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , RNA Ribossômico 28S/genética
14.
Res Microbiol ; 151(4): 263-70, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10875283

RESUMO

Until now, no simple and rapid technique existed for epidemiological study of strains belonging to the Nocardia genus. The application of the arbitrarily primed PCR procedure to generate randomly amplified polymorphic DNA (RAPD) fingerprints for such analysis of Nocardia isolates was investigated. Fifty-one unrelated clinical isolates of N. asteroides were tested. Two conditions of RAPD using two different primers generated RAPD fingerprints that allowed the differentiation of all strains. The patterns were reproducible and discriminating. The results highlight the diversity of N. asteroides species and confirm that RAPD analysis is a highly valuable tool for studying the epidemiology of the Nocardia genus. Several examples describe the advantage of RAPD analysis for establishing the relationship between isolates from a given patient (long-term infections, coinfections) and from different patients (i.e. during an outbreak). In the future, this technique will help us to investigate the source of infection in cases of nosocomial transmission, to understand the outcome of nocardiosis, and to follow the evolution and acquisition of resistance to Nocardia strains.


Assuntos
Nocardiose/microbiologia , Nocardia/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Técnicas de Tipagem Bacteriana , França , Humanos , Nocardia/classificação , Nocardiose/epidemiologia , Reprodutibilidade dos Testes , Estados Unidos
15.
Clin Microbiol Infect ; 6(2): 94-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11168079

RESUMO

OBJECTIVES: To find the antimicrobial susceptibility profile of 42 soil isolates of Nocardia asteroides against 14 antimicrobial agents representing beta-lactams, aminoglycosides, ciprofloxacin, minocycline, erythromycin and third generation cephalosporins. METHODS: The antimicrobial susceptibility was determined by the disk diffusion method using Mueller-Hinton agar medium. A homogeneous suspension giving an inoculum of 106-108 CFU/mL was used to streak the plates. The zone of inhibition was read after 36-48 h of incubation at 37 degrees C. RESULTS: All the soil isolates of N. asteroides were susceptible to amikacin, imipenem and tobramycin. Susceptibility to cephalosporins was quite variable; 86% of the isolates were susceptible to cefotaxime, 57% to ceftriaxone and 40% to cefamandole. Fifty-seven per cent of the isolates showed intermediate susceptibility to cefamandole, 33% to ceftriaxone and 5% to cefotaxime. Ninety-three per cent of the isolates were resistant to sulfamethoxazole alone or in combination with trimethoprim. CONCLUSIONS: The study reports a wide variation in the antimicrobial susceptibility profile of soil isolates of N. asteroides originating from a single geographical area. Of interest is the finding that over 90% of N. asteroides isolates were resistant to sulfamethoxazole without any previous exposure to this drug. This may have serious therapeutic implications as sulphonamides or the combination of trimethoprim-sulfamethoxazole is the therapy of choice for nocardiosis. Demonstration of resistance to beta-lactam antibiotics may be attributed to the presence of beta-lactamases which was detectable in > 90% of the soil strains of N. asteroides. The study underscores the importance of antimicrobial susceptibility testing for clinical isolates of Nocardia since individual strains show considerable differences in their susceptibility patterns necessitating therapeutic adjustments.


Assuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Nocardia asteroides/efeitos dos fármacos , Microbiologia do Solo , Kuweit , Testes de Sensibilidade Microbiana , Nocardia asteroides/citologia , Nocardia asteroides/enzimologia , Nocardia asteroides/isolamento & purificação , beta-Lactamases/metabolismo
16.
Genet Sel Evol ; 32(3): 311-20, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-14736395

RESUMO

Today, there is a shift towards a positional candidate approach in the molecular identification of genes. This study reports on an Expressed Sequence Tags (ESTs) mapping initiative in goats, based on sequence information gathered from a previous mammary gland cDNA systematic sequencing project. A total of 25 novel genes was localised cytogenetically on 16 goat chromosomes. Six of these ESTs were found to map to cattle milk QTL regions. These results made it possible to assess the use of ESTs as a shortcut to the molecular identification of some QTLs and as a valuable tool for comparative mapping.

17.
Eur J Endocrinol ; 141(3): 279-85, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10474126

RESUMO

Normotensive primary hyperaldosteronism is exceedingly rare. We report two new cases of this syndrome in two middle-aged women, one of Asian origin. The presenting signs were tetany in one case and an adrenal mass in the other. Neither patient had hypertension, despite repeated measurements with a manual armlet. A typical biological profile of primary hyperaldosteronism was demonstrated in both patients, including hypokalemia with inappropriate kaliuresis, elevated resting plasma aldosterone, and undetectable plasma renin activity. The circadian rhythm of blood pressure was studied by ambulatory monitoring pre- and post-operatively. It confirmed the lack of hypertension, but the circadian rhythm of blood pressure was lost before surgery in one patient. Surgical removal of the histologically typical aldosterone-producing adenomas normalized the kalemia. The main finding in these two patients was spontaneously low blood pressure in the post-operative period. This suggests that excess aldosterone induced relative hypertension in these patients whose blood pressure was spontaneously very low. Genetic screening for dexamethasone-sensitive hyperaldosteronism was negative in both patients.


Assuntos
Adenoma/metabolismo , Neoplasias das Glândulas Suprarrenais/fisiopatologia , Aldosterona/metabolismo , Hiperaldosteronismo/fisiopatologia , Hipertensão/complicações , Adenoma/cirurgia , Neoplasias das Glândulas Suprarrenais/cirurgia , Adulto , Aldosterona/sangue , Aldosterona/urina , Fator Natriurético Atrial/sangue , Monitorização Ambulatorial da Pressão Arterial , Southern Blotting , Cromatografia Líquida de Alta Pressão , Dexametasona/farmacologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hiperaldosteronismo/genética , Hiperaldosteronismo/cirurgia , Hipertensão/fisiopatologia , Potássio/sangue , Potássio/urina , Radioimunoensaio , Renina/sangue , Tetania , Tomografia Computadorizada por Raios X
18.
Med Mycol ; 37(3): 169-74, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10421848

RESUMO

We studied fungemia over time in outbred mice infected with Cryptococcus neoformans and looked at its relationship with the intravenous (i.v.) inoculum size, tissue burden and survival. Fungemia was evaluated by culture of 10 microl of peripheral blood from living mice or by culture of buffy coats from sacrificed animals. For all inoculum sizes studied, fungemia could last several weeks after the i.v. inoculation. Individual susceptibility of outbred mice to cryptococcal infection was evidenced by variations in the course, duration and magnitude of fungemia and tissue localizations. These results suggest that the fungus can recirculate after the initial i.v. inoculation. Fungemia, assessed by culture of buffy coats, correlated with the extent of infection in the spleen, lung or brain (P<<0.001) on day 1 after inoculation but only with yeast burden in lung or spleen on day 8, thus demonstrating that brain reacts differently to C. neoformans infection than other organs. Comparison of blood culture techniques and examination of smears suggest that cryptococci might circulate within leucocytes. Finally, quantitative blood cultures may accurately assess the fungal load during experimental cryptococcosis.


Assuntos
Criptococose/fisiopatologia , Fungemia/fisiopatologia , Animais , Criptococose/sangue , Criptococose/microbiologia , Cryptococcus neoformans/crescimento & desenvolvimento , Fungemia/microbiologia , Masculino , Camundongos
19.
J Clin Microbiol ; 37(1): 99-102, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9854071

RESUMO

Two regions of the gene coding for 16S rRNA in Nocardia species were selected as genus-specific primer sequences for a PCR assay. The PCR protocol was tested with 60 strains of clinically relevant Nocardia isolates and type strains. It gave positive results for all strains tested. Conversely, the PCR assay was negative for all tested species belonging to the most closely related genera, including Dietzia, Gordona, Mycobacterium, Rhodococcus, Streptomyces, and Tsukamurella. Besides, unlike the latter group of isolates, all Nocardia strains exhibited one MlnI recognition site but no SacI restriction site. This assay offers a specific and rapid alternative to chemotaxonomic methods for the identification of Nocardia spp. isolated from pathogenic samples.


Assuntos
Nocardia/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Técnicas Bacteriológicas , Sequência de Bases , Humanos , Dados de Sequência Molecular , Nocardia/genética , Sensibilidade e Especificidade , Alinhamento de Sequência , Especificidade da Espécie
20.
Mycopathologia ; 143(3): 151-4, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10353211

RESUMO

In this study, using the API-ZYM system, we have reported the enzyme profile of 42 soil strains and 2 clinical strains of Nocardia asteroides isolated locally. Of the 19 enzymes tested, only 7 were demonstrable in over 90% of the soil isolates. These included alkaline phosphatase, esterase lipase, leucine arylamidase, acid phosphatase, phosphohydrolase, alpha-glucosidase and beta-glucosidase. In addition, beta-galactosidase activity was demonstrated in all the strains by the O-nitrophenyl-beta-D-galactopyranoside (ONPG) test. The enzymes which were not demonstrable in > 95% of the strains included valine arylamidase, cystine arylamidase, trypsin, chymotrypsin, alpha-galactosidase, beta-glucoronidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase and alpha-fucosidase. With the exception of valine arylamidase, which was lacking in all but one isolate, the enzyme profiles of the soil isolates were comparable with the clinical isolates of N. asteroides reported in previous studies. The reasons for this difference in the two sets of isolates is not clear. The study reinforces the view that specific differences in the enzymatic profiles of Nocardia species could be used for their rapid identification. However, more extensive studies are needed to establish the reproducibility of this method. To the best of our knowledge, this is the first study of the enzymatic profile of soil isolates of N. asteroides originating from a single geographic region.


Assuntos
Esterases/metabolismo , Hidrolases/metabolismo , Nocardia asteroides/enzimologia , Microbiologia do Solo , Humanos , Kuweit , Nocardiose/microbiologia , Nocardia asteroides/classificação , Nocardia asteroides/isolamento & purificação , Kit de Reagentes para Diagnóstico
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