964 resultados para Restriction endonucleases


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A number of studies conducted in humans and in animals have observed that events occurring early in life are associated with the development of diseases in adulthood. Salt overload and restriction during pregnancy and lactation are responsible for functional (hemodynamic and hormonal) and structural alterations in adult offspring. Our group observed that lower birth weight and insulin resistance in adulthood is associated with salt restriction during pregnancy On the other hand, perinatal salt overload is associated with higher blood pressure and higher renal angiotensin II content in adult offspring. Therefore, we hypothesised that renin-angiotensin system (RAS) function is altered by changes in sodium intake during pregnancy. Such changes may influence fetoplacental blood flow and thereby fetal nutrient supply, with effects on growth in utero and, consequently, on birth weight. Female Wistar rats were fed low-salt (LS), normal-salt (NS), or high-salt (HS) diet, starting before conception and continuing until day 19 of pregnancy, Blood pressure, heart rate, fetuses and dams` body weight, placentae weight and litter size were measured on day 19 of pregnancy. Cardiac output, uterine and placental blood flow were also determined on day 19. Expressions of renin-angiotensin system components and of the TNF-alpha gene were evaluated in the placentae. Plasma renin activity (PRA) and plasma and tissue angiotensin-converting enzyme (ACE) activity, as well as plasma and placental levels of angiotensins I, II, and 1-7 were measured. Body weight and kidney mass were greater in HS than in NS and LS dams. Food intake did not differ among the maternal groups. Placental weight was lower in LS dams than in NS and HS dams. Fetal weight was lower in the US group than in the NS and HS groups. The PRA was greater in IS dams than in NS and HS dams, although ACE activity (serum, cardiac, renal, and placental) was unaffected by the level of sodium intake. Placental levels of angiotensins I and II were lower in the HS group than in the ISIS and IS groups. Placental angiotensin receptor type 1 (AT(1)) gene expression and levels of thiobarbituric acid reactive substances (TBARS) were higher in HS dams, as were uterine blood flow and cardiac output. The degree of salt intake did not influence plasma sodium, potassium or creatinine. Although fractional sodium excretion was higher in HS dams than in NS and LS dams, fractional potassium excretion was unchanged. In conclusion, findings from this study indicate that the reduction in fetal weight in response to salt restriction during pregnancy does not involve alterations in uterine-placental perfusion or the RAS. Moreover, no change in fetal weight is observed in response to salt overload during pregnancy. However, salt overload did lead to an increase in placental weight and uterine blood flow associated with alterations in maternal plasma and placental RAS. Therefore, these findings indicate that changes in salt intake during pregnancy lead to alterations in uterine-placental perfusion and fetal growth. (C) 2008 Elsevier Inc. All rights reserved.

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In this paper we describe the assembly and restriction map of a 1.05-Mb cosmid contig spanning the candidate region for familial Mediterranean fever (FMF), a recessively inherited disorder of inflammation localized to 16p13.3. Using a combination of cosmid walking and screening for P1, PAC, BAG, and YAC clones, we have generated a contig of genomic clones spanning similar to 1050 kb that contains the FMF critical region. The map consists of 179 cosmid, 15 P1, 10 PAC, 3 BAG, and 17 YAC clones, anchored by 27 STS markers. Eight additional STSs have been developed from the similar to 700 kb immediately centromeric to this genomic region. Five of the 35 STSs are microsatellites that have not been previously reported. NotI and EcoRI mapping of the overlapping cosmids, hybridization of restriction fragments from cosmids to one another, and STS analyses have been used to validate the assembly of the contig. Our contig totally subsumes the 250-kb interval recently reported, by founder haplotype analysis, to contain the FMF gene. Thus, our high-resolution clone map provides an ideal resource for transcriptional mapping toward the eventual identification of this disease gene. (C) 1997 Academic Press.

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Objective: We analyzed the influence of IUGR on the concentrations of plasma (Znpl) and erythrocyte (Zne) zinc and on the ratios of Zne to Znpl (Zne:Znpl) and Zne to hemoglobin (Zne:Hb) in term infants during the first month of life. Design: Cohort study. Setting: Tertiary Care Neonatal Unit. Subjects: Exclusively breastfed term newborns (n = 84) were divided into 3 groups: group 1, without IUGR (n = 41), group II. with mild to moderate IUGR (n = 12). and group III, with severe IUGR (n = 31). IUGR was defined as birth weight under the 5th percentile of the Alexander et at curve and as a Kramer Index (KI: ratio of birth weight to estimated weight for each gestational age) <0.85. Severe IUGR was defined as a KI <0.75. Znpl, Zne. and Hb were measured at birth. 3 days, and 1 month of life. Results: Znpl tended to decrease (P = 0.073), Zne and Zne:Znpl increased (P < 0.001), and Hb decreased (P < 0.001) during the first month of life. There was not Znpl, Zne and Zne:Znpl time by group interaction. Zne:Hb increased (P < 0.001) during the first month of life and was lower in Group II at I month of age. Differences between Groups I and If (P = 0.017) and Groups II and III at I month of age (P = 0.011) were detected. Conclusions: Our results suggest that IUGR did not have association with erythrocyte zinc and Zne:Hb ratio at birth. However. neonatal nutrition could have influenced zinc incorporation during this period, through Zne increase.

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Objectives. To examine the effects of betamethasone administration on umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV) Doppler flow. Design. Longitudinal prospective study. Setting: Fetal Surveillance Unit, Department of Obstetrics and Gynecology, University of Sao Paulo, Sao Paulo, Brazil. Population. Thirty-two singleton pregnancies complicated by fetal growth restriction with absent end-diastolic flow in the UA. Methods. Pulsatility index (PI) of the UA, MCA and DV was measured from 26 to 34 weeks prior to and within 24 or 48 hours after starting betamethasone treatment course. Analysis of variance for repeated measures was used to determine the changes in the fetal hemodynamic Doppler flow following maternal corticosteroid administration. Main outcome measures. Improvement of UA-PI within 24 hours and DV-PIV (venous pulsatility) within 48 hours from the first betamethasone dose. Results. Mean gestational age at delivery was 29.3 (1.8) weeks and birthweight was 806.6 (228.2) g. A reduction in the UA-PI was observed in 29 (90.6%) cases, with return of end-diastolic flow in 22 (68.7%). The mean UA-PI were 2.84 (0.52) before corticosteroid administration, 2.07 (0.56) within 24 hours and 2.42 (0.75) after 48 hours, with a significant difference along the evaluations (p0.001). No significant changes in the MCA Doppler were observed. DV-PIV decreased from 1.06 (0.23) prior corticosteroids administration to 0.73 (0.16) within 24 hours and 0.70 (0.19) after 48 hours (p0.001). Conclusions. There was reduction in the umbilical artery and in the DV pulsatility indices within 24 hours from betamethasone administration that was maintained up to 48 hours.

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Objective: To investigate glomerular development and expression of insulin and insulin-like growth factor receptors in an experimental model of intrauterine growth restriction (IUGR). Material and Methods: We studied three groups of Sprague-Dawley fetuses: IUGR - restricted by ligation of the right uterine artery; C-IUGR - left horn controls, and EC - external controls (non-manipulated). Body and organs were weighed, and glomerular number and volume were analyzed. Expression of IR beta, IRS-1, IRS-2 and IGF-IR beta was analyzed in liver, intestine and kidneys by immunoblotting. Results: Organ/body weight ratios were similar. In IUGR, glomerular number and volume were increased compared to C-IUGR and EC (p < 0.001). In the IUGR liver, increases were found in IGF-IR beta compared to C-IUGR and EC; IR beta compared to EC, and IRS-2 compared to C-IUGR. However, decreases in IR beta were noted in IUGR compared to C-IUGR; IRS-1 compared to C-IUGR and EC, and IRS-2 compared to EC. In IUGR intestine, increases were detected in IR beta, IRS-1 and IGF-IR beta compared to C-IUGR and EC. In IUGR kidneys, increases were observed in IR beta and IGF-IR beta compared to C-IUGR and EC, and IRS-1 compared to EC. Decreased IRS-2 in the intestine and kidney were noticed in IUGR compared to C-IUGR and EC. Conclusion: IUGR fetuses had less glomeruli and alterations in insulin receptors, which may be associated with an increased risk of disease occurrence in adulthood. Copyright (C) 2010 S. Karger AG, Basel

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Experimental animal studies have shown that nicotine exposure during gestation alters the expression of fetal hypothalamic neuropeptides involved in the control of appetite. We aimed to determine whether the exposure to maternal smoking during gestation in humans is associated with an altered feeding behavior of the adult offspring. A longitudinal prospective cohort study was conducted including all births from Ribeirao Preto (Sao Paulo, Brazil) between 1978 and 1979. At 24 years of age, a representative random sample was re-evaluated and divided into groups exposed (n = 424) or not (n = 1586) to maternal smoking during gestation. Feeding behavior was analyzed using a food frequency questionnaire. Covariance analysis was used for continuous data and the chi(2) test for categorical data. Results were adjusted for birth weight ratio, body mass index, gender, physical activity and smoking, as well as maternal and subjects` schooling. Individuals exposed to maternal smoking during gestation ate more carbohydrates than proteins (as per the carbohydrate-to-protein ratio) than non-exposed individuals. There were no differences in the consumption of the macronutrients themselves. We propose that this adverse fetal life event programs the individual`s physiology and metabolism persistently, leading to an altered feeding behavior that could contribute to the development of chronic diseases in the long term.

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Caloric intake reduction has been considered as the major experimental manipulation able to increase longevity in experimental models. Therefore, its effects upon cognition and mood like behavior are poorly explored. On the other hand, Li(+) is a re-emergent therapeutic drug used to treat mood disorders, mainly bipolar disorder, with antipanic and antidepressant actions. On the hypothesis that lithium treatment could attenuate the negatives effects of stress on Central Nervous Systems (CNS), we evaluated the role of chronic lithium treatment on anxiety-like behaviors in animals submitted to stress by chronic moderated feed restriction (FR). Male wistar rats were divided into four groups (n = 7-8/group) according to dietary and drug manipulation: ad libitum (AL) with unlimited access to standard rat diet, lithium treatment ( AL + Li) which received approximately 50 mg/Kg animal/day of LiCl solved in water and ad libitum diet, FR that were fed with equivalent to 70% of total rat diet consumed by AL group, and FR + Li which received diet corresponding to FR and Li administration. After 12 weeks of drug and FR manipulation, anxiety like behavior was evaluated in elevated plus mazes (EPM). Chronic lithium treatment prevent the anxiogenic like effect of FR ( open time, F(3,30) = 3.588; P = 0.0265; percentage of open entries, F(3,30) = 6.004; P= 0.00029; and open time at the first min, 2.35; F(3,30) = 4.937; P = 0.0073, Duncan test P < 0.05) compared to AL diet. Ours results adding to evidences that moderate feed restriction my increase anxiety-like behavior; also suggest that chronic lithium treatment may be attenuated this effects.

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At the end of 2002 and throughout 2003, there was a severe outbreak of infectious laryngotracheitis (ILT) in an intensive production area of commercial hens in the Sao Paulo State of Brazil. ILT virus was isolated from 28 flocks, and 21 isolates were genotyped by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) using four genes and eight restriction enzymes, and by partial sequencing of the infected cell protein 4 (ICP4) and thymidine kinase (TK) genes. Three groups resulted from the combinations of PCR-RFLP patterns: 19 field isolates formed Group I, and the remaining two isolates together with the chicken embryo origin (CEO) vaccine strains formed Group II. Group III comprised the tissue-culture origin (TCO) vaccine strain by itself. The PCR-RFLP results agreed with the sequencing results of two ICP4 gene fragments. The ICP4 gene sequence analysis showed that the 19 field isolates classified into Group I by RFLP-PCR were identical among themselves, but were different to the TCO and CEO vaccines. The two Group II isolates could not be distinguished from one of the CEO vaccines. The nucleotide and amino acid sequence analyses discriminated between the Brazilian and non-Brazilian isolates, as well as between the TCO and CEO vaccines. Sequence analysis of the TK gene enabled classification of the field isolates (Group I) as virulent and non-vaccine. This work shows that the severe ILT outbreak was caused by a highly virulent, non-vaccine strain.

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A repetitive DNA motif was used as a marker to identify novel genes in the mucosal pathogen Moraxella catarrhalis. There is a high prevalence of such repetitive motifs in virulence genes that display phase variable expression. Two repeat containing loci were identified using a digoxigenin-labelled 5'-(CAAC)(6)-3' oligonucleotide probe. The repeats are located in the methylase components of two distinct type III restriction-modification (R-M) systems. We suggest that the phase variable nature of these R-M systems indicates that they have an important role in the biology of M. catarrhalis. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.

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Members of the Culex sitiens subgroup are important vectors of arboviruses, including Japanese encephalitis virus, Murray Valley encephalitis virus and Ross River virus. Of the eight described species, Cx. annulirostris Skuse, Cx. sitiens Wiedemann, and Cx. palpalis Taylor appear to be the most abundant and widespread throughout northern Australia and Papua New Guinea (PNG). Recent investigations using allozymes have shown this subgroup to contain cryptic species that possess overlapping adult morphology. We report the development of a polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) procedure that reliably separates these three species. This procedure utilizes the sequence variation in the ribosomal DNA ITS1 and demonstrates species-specific PCR-RFLP profiles from both colony and field collected material. Assessment of the consistency of this procedure was undertaken on mosquitoes sampled from a wide geographic area including Australia, PNG, and the Solomon Islands. Overlapping adult morphology was observed for Cx. annulirostris and Cx. palpalis in both northern Queensland and PNG and for all three species at one site in northwest Queensland.

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The utility of 16s rDNA restriction fragment length polymorphism (RFLP) analysis for the partial genomovar differentiation of Burkholderia cepacia complex bacterium is well documented. We compared the 16s rDNA RFLP signatures for a number of non-fermenting gram negative bacilli (NF GNB) LMG control strains and clinical isolates pertaining to the genera Burkholderia, Pseudomonas, Achromobacter (Alcaligenes), Ralstonia, Stenotrophomonas and Pandoraea. A collection of 24 control strain (LMG) and 25 clinical isolates were included in the study. Using conventional PCR, a 1.2 kbp 16s rDNA fragment was generated for each organism. Following restriction digestion and electrophoresis, each clinical isolate RFLP signature was compared to those of the control strain panel. Nineteen different RFLP signatures were detected from the 28 control strains included in the study. TwentyoneyTwenty- five of the clinical isolates could be classified by RFLP analysis into a single genus and species when compared to the patterns produced by the control strain panel. Four clinical B. pseudomallei isolates produced RFLP signatures which were indistinguishable from B. cepacia genomovars I, III and VIII. The identity of these four isolates were confirmed using B. pseudomallei specific PCR. 16s rDNA RFLP analysis can be a useful identification strategy when applied to NF GNB, particularly for those which exhibit colistin sulfate resistance. The use of this molecular based methodology has proved very useful in the setting of a CF referral laboratory particularly when utilised in conjunction with B. cepacia complex and genomovar specific PCR techniques. Species specific PCR or sequence analysis should be considered for selected isolates; especially where discrepancies between epidemiology, phenotypic and genotypic characteristics occur.

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In this paper we investigate some classes of semigroup rings with respect to (semi)primeness and (semi)primitivity. We do so by extending the techniques developed by Munn in (Proc R Soc Edinbur Sect A 107:175-196, 1987) and (Proc R Soc Edinbur Sect A 115:109-117, 1990) for the study of semigroup rings of inverse semigroups. Restriction, weakly ample and ample semigroups are considered.

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More than 70 species of mycobacteria have been defined, and some can cause disease in humans, especially in immunocompromised patients. Species identification in most clinical laboratories is based on phenotypic characteristics and biochemical tests and final results are obtained only after two to four weeks. Quick identification methods, by reducing time for diagnosis, could expedite institution of specific treatment, increasing chances of success. PCR restriction-enzyme analysis (PRA) of the hsp65 gene was used as a rapid method for identification of 103 clinical isolates. Band patterns were interpreted by comparison with published tables and patterns available at an Internet site (http://www.hospvd.ch:8005). Concordant results of PRA and biochemical identification were obtained in 76 out of 83 isolates (91.5%). Results from 20 isolates could not be compared due to inconclusive PRA or biochemical identification. The results of this work showed that PRA could improve identification of mycobacteria in a routine setting because it is accurate, fast, and cheaper than conventional phenotypic identification.

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Introduction: Maternal HIV infection and related co-morbidities may have two outstanding consequences to fetal health: mother-to-child transmission (MTCT) and adverse perinatal outcomes. After Brazilian success in reducing MTCT, the attention must now be diverted to the potentially increased risk for preterm birth (PTB) and intrauterine fetal growth restriction (IUGR). Objective: To determine the prevalence of PTB and IUGR in low income, antiretroviral users, publicly assisted, HIV-infected women and to verify its relation to the HIV infection stage. Patients and Methods: Out of 250 deliveries from HIV-infected mothers that delivered at a tertiary public university hospital in the city of Vitória, state of Espírito Santo, Southeastern Brazil, from November 2001 to May 2012, 74 single pregnancies were selected for study, with ultrasound validated gestational age (GA) and data on birth dimensions: fetal weight (FW), birth length (BL), head and abdominal circumferences (HC, AC). The data were extracted from clinical and pathological records, and the outcomes summarized as proportions of preterm birth (PTB, < 37 weeks), low birth weight (LBW, < 2500g) and small (SGA), adequate (AGA) and large (LGA) for GA, defined as having a value below, between or beyond the ±1.28 z/GA score, the usual clinical cut-off to demarcate the 10th and 90th percentiles. Results: PTB was observed in 17.5%, LBW in 20.2% and SGA FW, BL, HC and AC in 16.2%, 19.1%, 13.8%, and 17.4% respectively. The proportions in HIV-only and AIDS cases were: PTB: 5.9 versus 27.5%, LBW: 14.7% versus 25.0%, SGA BW: 17.6% versus 15.0%, BL: 6.0% versus 30.0%, HC: 9.0% versus 17.9%, and AC: 13.3% versus 21.2%; only SGA BL attained a significant difference. Out of 15 cases of LBW, eight (53.3%) were preterm only, four (26.7%) were SGA only, and three (20.0%) were both PTB and SGA cases. A concomitant presence of, at least, two SGA dimensions in the same fetus was frequent. Conclusions: The proportions of preterm birth and low birth weight were higher than the local and Brazilian prevalence and a trend was observed for higher proportions of SGA fetal dimensions than the expected population distribution in this small casuistry of newborn from the HIV-infected, low income, antiretroviral users, and publicly assisted pregnant women. A trend for higher prevalence of PTB, LBW and SGA fetal dimensions was also observed in infants born to mothers with AIDS compared to HIV-infected mothers without AIDS.