Time course of vasopressin and oxytocin secretion after stress in adrenalectomized rats

To characterize the participation of vasopressin (AVP) and oxytocin (OT) in hypothalamus-pituitary-adrenal regulation after adrenalectomy (ADX), we evaluated corticosterone, ACTH, AVP and OT plasma concentrations and AVP and OT content of the paraventricular nucleus (PVN) at different periods (3 h, 1, 3, 7 and 14 days) in sham or ADX rats under basal conditions and after immobilization stress. ADX animals showed undetectable corticosterone levels, while sham animals showed a marked increase in corticosterone and ACTH 3 h after surgery, then lowering to basal control levels. ADX rats showed high basal ACTH levels with a triphasic response without changes after immobilization. After three hours, the ADX group showed higher OT levels than the sham group. OT was increased after immobilization stress in sham and ADX groups. AVP plasma levels did not change throughout the basal or stress studies in either group. There was a decrease in hypothalamic AVP content 1 and 3 days after ADX under basal and stress conditions. Plasma osmolality showed a significant decrease in the ADX group at 3, 7, and 14 days. In conclusion, there are different pituitary-adrenal axis set points after removal of the glucocorticoid negative feedback. The role of vasopressinergic and oxytocinergic neurons in the ACTH secretion after ADX or immobilization stress appears to differ. Magnocellular AVP is unlikely to contribute to ACTH secretion in response to ADX or immobilization stress. On the other hand, OT is elicited by immobilization stress and might contribute to the ACTH secretion during short-term ADX.

Evaluation of management strategies for reducing nitrogen loadings to four US estuaries

In this study we used the Watershed Assessment Tool for Evaluating Reduction Strategies for Nitrogen (WATERSN) model to evaluate a variety of management strategies for reducing nitrogen (N) loads to four US east coast estuaries: Casco Bay, Long Island Sound, Chesapeake Bay and Pamlico Sound. These management strategies encompass reductions in atmospheric emissions and deposition of N from sources including, fossil fuel burning utility emissions and mobile NO(x) emissions, N treatment in wastewater and controls on agricultural N inputs. We find that in primarily urban watersheds biological removal of N in wastewater treatment produces the greatest reduction in N loading (32-57% reductions), while in less urban watersheds, reductions in agricultural loading are more effective (5-56% reductions) in decreasing N loads to coastal ecosystems. Because anthropogenic N inputs are derived from a variety of sources, we also examined an integrated scenario targeting all major N sources; this resulted in 35-58% reductions in N loading. Nitrogen pollution originates from multiple sources and is transported through several media (air, soil, water); a major challenge of the development of N management strategies will be the control of multiple sources to effectively reduce N loads to estuaries.

Complications of home parenteral nutrition in a large pediatric series

When adequate nutrition cannot be provided by enteral route as a consequence of failure of intestinal functions, parenteral nutrition (PN) become the only way to maintain adequate nutrition; however, prolonged periods of PN can lead to severe complications. Furthermore, long hospital admissions for this form of nutrition can be detrimental for the child and the family. In the past 20 years, home parenteral nutrition (HPN) programs have been developed. The aim of our study was to retrospectively evaluate the kind and the frequency of complications in a HPN pediatric case series. We had 61 patients on HPN. Total duration of the program was 27,740 days (76 total years, mean 1.2 years per patient). We observed a total of 58 complications; mean 0.79 per patient per year with a prevalence of central venous catheter-related complications (mechanical, 52%; infective, 26%). We had a very low incidence of metabolic complications (3%) and a low incidence of PN-related hepatic complications (19%). None of the complications described was the cause of death. Half of our patients have been able to stop the program. We had a low incidence (0.20 per patient per year) of septic episodes, lower than we had in patients on hospital PN in the same period (0.38 per patient per year). We had to replace 20 catheters, 18 of them for mechanical problems. Our study shows that HPN still can be a valid alternative to small intestinal transplantation in patients affected by intestinal failure and that only patients with PN-related liver disease must be considered early candidates for combined liver-small bowel transplant.

Intractable diarrhea of infancy with congenital intestinal mucosa abnormalities: outcome of four cases

Microvillous inclusion disease (MID) and epithelial dysplasia (ED) or tufting enteropathy are the most frequent causes of intractable diarrhea with persistent villous atrophy and indefinite dependence on total parenteral nutrition (PN) from early infancy. Since these are intractable diseases, they have been proposed to be elective indication for early bowel transplantation in order to avoid complications, such as PN-related liver disease, that would require a combined small bowel-liver transplant. We describe four cases of intractable diarrhea, two with MID and two with ED, seeking to discover whether these diseases are really elective, early indications for bowel transplant. Among our four patients, only one with ED underwent transplantation. The prognosis of small bowel transplant is still poor and worse than that of prolonged HPN. Further study is necessary to achieve a safe HPN program. Referral for transplant (small bowel only or combined with liver) should be considered when there is a venous access reduction and/or severe and irreversible liver disease.

Prevalence of liver complications in pediatric patients on home parenteral nutrition: indications for intestinal or combined liver-intestinal transplantation

Parenteral nutrition (PN) is the only treatment for patients affected by chronic intestinal failure (CIF). Home parenteral nutrition (HPN) programs are started when patients need prolonged PN. Unfortunately, many patients on prolonged PN develop liver disease (LD). The aim of our study was to assess the prevalence of LD in our series of patients on HPN. We reviewed our records of patients discharged from the hospital on HPN for CIF. HPN was started when one parent was fully trained in the use of this treatment and if the social and familial home environment was reliable. All patients received total PN by a central venous catheter. All patients with abnormal AST, ALT, ALK, gammaGT, and bilirubin values for more than 3 months were considered affected by PN-related LD. Thirty-six patients (23 of whom were boys and 13 girls) were discharged on HPN. During the study period, for CIF, 16 were affected by short bowel syndrome (SBS), of whom 6 had ultra-short bowel; 16 with functional intestinal failure, and 4 with chronic intestinal pseudobstruction (CIPO). Mean duration of HPN was 2.1 years/patient. Nine of 36 patients (25%) on HPN for CIF showed LD. Seven of the 16 patients (43%) with LD were affected by SBS and 2 (12.5%) patients by functional intestinal failure. No patients with CIPO developed LD. In patients affected by SBS, the onset of LD was very earlier than in patients with ID.

Measuring lysosomal stability as an effective tool for marine coastal environmental monitoring

The use of lysosomal stability in the mussel, Mytilus galloprovincialis, as a potential biomarker of environmental contamination has been evaluated along the Portuguese coast. To this end, the neutral red retention (NRR) time was measured in mussel haemocytes gathered from nine different locations reflecting different degrees of anthropogenic contamination. Mussels collected in the vicinity of industrial and urban areas showed the lowest lysosomal stability. Additionally, no significant seasonal variability (winter-spring/summer) for NRR time was observed. In order to further support the usefulness of this method as an integrated tool for monitoring marine coastal environments, we compared the levels of xenobiotics in mussel tissues with the obtained NRR values. The results highlighted a consistent pattern, with the lowest lysosomal stability intimately correlated with the higher contaminant concentrations. In summary, this integrated approach further demonstrated that the NRR assay can provide useful and objective indications of the real health status of organisms subjected to different stress agents, being a valid option for environmental monitoring.

Inhibin alpha-subunit (INHA) gene and locus changes in paediatric adrenocortical tumours from TP53 R337H mutation heterozygote carriers

The R337H TP53 mutation is a low-penetrance molecular defect that predisposes to adrenocortical tumour (ACT) formation in Brazilian and possibly other populations. Additional genetic defects may be responsible for the variable expression of ACTs in these cases. The inhibin alpha-subunit gene (INHA) on 2q33-qter has been implicated in mouse adrenocortical tumourigenesis. We studied 46 pediatric patients with ACTs from Brazil for INHA genetic alterations; 39 of these patients were heterozygous carriers of the R337H TP53 mutation. We first mapped the INHA gene by radiation hybrid analysis and determined 10 linked microsatellite markers in an area flanked by D2S1371 and D2S206 on 2q33-qter. These markers were then used for loss of heterozygozity (LOH) studies in nine paired germline and tumour DNA samples. Mapping placed the INHA gene in close proximity to D2S2848 (SHGC11864) with a log of odds (LOD) score of 5.84. LOH for at least one marker in the region was identified in 8/9 tumours (89%). Six patients were heterozygous for three INHA mutations: one in exon 1, 127C>G, and two in exon 2, 3998G>A and 4088G>A, all leading to amino acid substitutions (P43A, G227R, and A257T, respectively). A257T is located in a conserved INHA region, highly homologous to transforming growth factor-beta; both G227R and A257T change polarity, and, in addition, G227R changes the pH. We conclude that these sequence alterations and the detected 2q allelic changes suggest that INHA may be one of the contributing factors needed for ACT formation in pediatric patient carriers of the R337H TP53 mutation.

Interaction of prolactin, ANPergic, oxytocinergic and adrenal systems in response to extracellular volume expansion in rats

The present study evaluated the effect of acute extracellular volume expansion (EVE) induced by intravenous injection of isotonic (0.15 m NaCl) or hypertonic saline (0.3 m NaCl) on prolactin, corticosterone, vasopressin, oxytocin and atrial natriuretic peptide (ANP) secretion. Male Wistar rats were treated with bromocriptine, sulpiride or dexamethasone. After isotonic and hypertonic EVE, the control group showed a significant increase in the plasma concentrations of prolactin, corticosterone, ANP and oxytocin. The increase in ANP and oxytocin levels in response to hypertonic EVE was more pronounced than to isotonic EVE. Bromocriptine and sulpiride treatments did not modify corticosterone, ANP and oxytocin responses to either isotonic or hypertonic EVE. The increases in prolactin and oxytocin, but not ANP, were blocked in dexamethasone pretreated rats. In conclusion, isotonic or hypertonic EVE induced an increase in the plasma concentrations of prolactin, corticosterone, ANP and oxytocin. The increases in ANP and oxytocin were independent of plasma concentrations of prolactin. The increases in prolactin and oxytocin were blocked by the inhibition of the hypothalamo-pituitary-adrenal (HPA) axis by dexamethasone. However, dexamethasone did not alter the increase in ANP secretion induced by isotonic or hypertonic EVE. Therefore, prolactin might participate in regulation of the hydroelectrolytic balance in mammals; however, in the present study, there was no evidence for direct interaction with ANPergic and oxytocinergic systems. In addition, the responses of prolactin and oxytocin induced by isotonic or hypertonic EVE are modulated by the HPA axis.

Surface studies on acrylic bone cement

Poly(methyl methacrylate) (PMMA) is used to fill the gap between the prosthesis and the surrounding bone in cemented arthroplasties. Biocompatibility problems related to bone cement application limit the clinical success of these cemented arthroplasties. Being the cement surface in close connection with the living bone, it is reasonable to assume that surface properties such as, surface composition and surface energy, will play a role in the biomaterial performance. X-ray photoelectron spectroscopy (XPS) analysis and surface energy studies were carried out during 4 months, in order to assess a possible correlation between aging time and surface changes. The aging of PMMA, in a biological model fluid, strongly influences the composition and wettability of the cement surface. These changes may be explained through the hydrolysis of PMMA ester groups and the subsequent hydrogen bonding. Although our study does not exactly reproduce the in vivo environment surrounding a prosthesis, it suggests that the changes in the composition and wettability of the surface may modulate the host response towards the implant, thus contributing to its loosening.

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.

Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV

Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

Azimuthal anisotropy at the relativistic heavy ion collider: the first and fourth harmonics

We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported.

Particle-type dependence of azimuthal anisotropy and nuclear modification of particle production in Au+Au collisions at square root of sNN=200 GeV

We present STAR measurements of the azimuthal anisotropy parameter v(2) and the binary-collision scaled centrality ratio R(CP) for kaons and lambdas (Lambda+Lambda) at midrapidity in Au+Au collisions at square root of s(NN)=200 GeV. In combination, the v(2) and R(CP) particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p(T) approximately 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K(0)(S) and Lambda+Lambda v(2) values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

Serological status and abortion rate in progeny obtained by natural service or embryo transfer from Neospora caninum-seropositive cows

Bovine neosporosis is an important disease in dairy herds in Argentina. Embryo transfer (ET) technology offers the opportunity to minimize vertical transmission of neosporosis. The objective of this work was to compare the serological status and the incidence of abortion between heifers obtained via natural service and heifers obtained by ET from Neospora-infected cows. Progeny from eight Neospora-infected cows belonging to a commercial dairy farm where ET was routinely performed were studied. Between 1996 and 2001, 16 and 15 heifers were obtained by natural service and ET, respectively. Serostatus and reproductive performance were recorded in both progeny. Serostatus was determined by indirect fluorescent antibody test (IFAT). All heifers obtained by natural service were seropositive and six of 16 pregnancies ended in abortion. All heifers obtained by ET were seronegative and only two abortions of 15 pregnancies were recorded.

Multiple paternity in Norway lobster (Nephrops norvegicus L.) assessed with microsatellite markers

We investigated genetic diversity and the mating system of the Norway lobster (Nephrops norvegicus) in a wild population off the Portuguese coast. Approximately 100 individuals were screened for 2 microsatellite loci. For 11 ovigerous lobsters both the female and a sample of her offspring (24 eggs) were genotyped. High genetic diversity was observed for the 2 markers in the population. Paternity within broods was analyzed by comparing multilocus genotypes of each egg with the corresponding mother, and the male parent contribution was then deduced. Multiple paternity was observed in 6 of the 11 broods studied. In those cases, 2 to 3 male parents were likely to have contributed to the fertilization of the eggs. When multiple paternity was involved, the comparative reproductive success of the male parents was quite even. This is the first report of multiple paternity in the Norway lobster. Comparisons with other taxa are presented, and consequences of multiple paternity are discussed.

Pion-Kaon correlations in central Au+Au collisions at square root [sNN] = 130 GeV

Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at sqrt[s(NN)]=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.

Three-pion Hanbury Brown-Twiss correlations in relativistic heavy-ion collisions from the STAR experiment

Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at sqrt[s(NN)]=130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freeze-out. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

Prevention of hypertension attenuates albuminuria and renal expression of fibronectin in diabetic spontaneously hypertensive rats

BACKGROUND/AIM

The aim of this study was to evaluate the effect of preventing hypertension on renal disease in a model of genetic hypertension and diabetes.

METHODS

Four-week-old spontaneously hypertensive rats (SHR) with streptozotocin-induced diabetes were randomized for no treatment, or for treatment with captopril, losartan or triple therapy (hydrochlorothiazide, reserpine and hydralazine) for 16 weeks.

RESULTS

Increase in systolic blood pressure was equally prevented by captopril (128 +/- 3 mm Hg), losartan (128 +/- 2) and triple therapy (129 +/- 2, p < 0.0001). Albuminuria was similarly reduced by captopril (499 (404-659)), losartan (622 (470-976)) and triple therapy (479 (362-600) microg/24 h (p < 0.0001)). Renal fibronectin expression increased in diabetic SHR (125 +/- 13 densitometric unit) as compared to the controls (51 +/- 9, p < 0.0001), and decreased (p < 0.0001 vs. diabetic SHR) with captopril (32 +/- 8), losartan (27 +/- 4) and triple therapy (35 +/- 6).

CONCLUSION

The prevention of hypertension in diabetic SHR by captopril, losartan or triple therapy was equally efficacious in impeding increase of albuminuria and the expression of renal fibronectin. Under these conditions, tight blood pressure control was the main determinant in attenuating nephropathy.

Transverse-momentum and collision-energy dependence of high-pT hadron suppression in Au+Au collisions at ultrarelativistic energies

We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for 5<p(T)<12 GeV/c. The collision energy dependence of the yields and the centrality and p(T) dependence of the suppression provide stringent constraints on theoretical models of suppression. Models incorporating initial-state gluon saturation or partonic energy loss in dense matter are largely consistent with observations. We observe no evidence of p(T)-dependent suppression, which may be expected from models incorporating jet attenuation in cold nuclear matter or scattering of fragmentation hadrons.

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia

Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76% of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19%), V281L (18%), and IVS2,A/C>G,-12 (15%). In the SW form, the most frequent mutation was IVS2,A/C>G,-12 (38%), in the SV form it was I172N (53%), and in the NC form it was V281L (57.7%). We observed a good correlation between genotype and phenotype. Discordance between genotype and phenotype was found in one SV patient with a mild mutation in one of the alleles (R356W/V281L). However, we cannot rule out the presence of an additional mutation in these alleles. We also observed a good correlation of genotype with 17alpha-hydroxyprogesterone, testosterone, and androstenedione levels. The severity of external genitalia virilization correlated with the severity of mutation. In conclusion, the frequencies described in the present study did not differ from worldwide studies, including the Brazilian population. The few differences observed may reflect individual sample variations. This new Brazilian cohort study suggests the presence of new mutations in Brazilian patients with different forms of CAH-21OH.

Susceptibility and exposure biomarkers in people exposed to PAHs from diesel exhaust

Xenobiotic metabolizing enzymes, especially CYP1A1 and GSTM1, are involved in the activation and conjugation of PAHs and are controlled by polymorphic genes. PAHs released from diesel emissions in many cities of the world, especially in developing countries, contribute significantly to the toxic effects of airborne inhalable particles. We have evaluated the gene-environment interaction in Santiago of Chile, studying the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-P urinary levels used as the PAHs exposure biomarker. The study was performed on 59 diesel exposed (38 diesel revision workers and 21 subjects working in an urban area as established street vendors) and 44 non-exposed subjects living in a rural area. The 1-OH-P urinary levels of the urban (P=0.043) and rural (P=0.040) populations showed, without considering the genotypes, significant differences between smokers and non-smokers, but no significant differences were found between smokers and non-smokers among the diesel plant workers (P=0.33). Non-smoking subjects of the diesel plants and the urban area showed similar 1-OHP levels (P=0.466) which were significantly higher than those of the subjects living in the rural area (P<0.05). When 1-OH-P levels were related with genotypes, an association was observed for the CYP1A1*2A genotype, so that the diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype (P=0.008). On the other hand, there was no significant correlation between urinary 1-OH-P levels and GSTM1 null genotype, although higher levels of the urinary metabolite were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype (P=0.055). These results may suggest an association between levels of the exposure biomarker 1-OH-P and presence of the CYP1A1*2A genotype, a potential genetic susceptibility biomarker which might be useful in identifying individuals at higher risk among people exposed to high PAH levels in diesel exhaust.

Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC

We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.