Parasympathetic dysautonomia precedes left ventricular systolic dysfunction in Chagas disease

BACKGROUND

Parasympathetic dysautonomia is an established feature of advanced Chagas cardiomyopathy. However, in the absence of cardiac involvement, the presence of vagal dysfunction remains controversial. In a cross-sectional study, we compared patients with Chagas disease without cardiac involvement and healthy individuals by three different methods to determine whether vagal dysfunction is present in the early phase of Chagas disease.

METHODS

Sixty-one patients with Chagas disease without cardiac involvement and 38 controls were submitted to respiratory sinus arrhythmia test and 24-hour Holter monitoring. Vagal heart influences were assessed by the expiratory/inspiratory (E/I) ratio, time-domain indexes of heart rate variability (HRV), and by the quantification of a 3-dimensional return map.

RESULTS

The two groups were comparable in terms of left ventricular ejection fraction and left ventricular end-diastolic dimension. Compared with the control group, patients with Chagas disease had significantly lower values of the E/I ratio (mean +/- SD: 1.38 +/- 0.02 and 1.25 +/- 0.02, P <.004) and short-term indexes of HRV (median [interquartile range]-rMSSD: 23 [18-27] and 17 [13-23], P =.00; pNN50: 11 [7-17] and 6 [2-12], P =.00). P(3), a beat-to-beat HRV index derived from the 3-dimensional return map, also was significantly reduced in the Chagas disease group (mean +/- SD: 118 +/- 5 vs 100 +/- 4, P =.00). None of these indexes of vagal heart control were significantly correlated with left ventricular function or to the presence of esophageal radiologic abnormalities.

CONCLUSION

Parasympathetic dysautonomia is an independent and early phenomenon in Chagas disease and may precede left ventricular systolic dysfunction.

Maternal low-protein diet during lactation programmes body composition and glucose homeostasis in the adult rat offspring

Previously we have reported that maternal malnutrition during lactation programmes body weight and thyroid function in the adult offspring. In the present study we evaluated the effect of maternal protein restriction during lactation upon body composition and hormones related to glucose homeostasis in adult rats. During lactation, Wistar lactating rats and their pups were divided into two experimental groups: control (fed a normal diet; 23 % protein) and protein-restricted (PR; fed a diet containing 8 % protein). At weaning, offspring received a normal diet until they were 180 d old. Body weight (BW) and food intake were monitored. Serum, adrenal glands, visceral fat mass (VFM) and carcasses were collected. PR rats showed lower BW ( − 13 %;P < 0·05), VFM ( − 33 %;P < 0·05), total body fat ( − 33 %;P < 0·05), serum glucose ( − 7 %;P < 0·05), serum insulin ( − 26 %,P < 0·05), homeostasis model assessment index ( − 20 %), but higher total adrenal catecholamine content (+90 %;P < 0·05) and serum corticosterone concentration (+51 %;P < 0·05). No change was observed in food intake, protein mass or total body water. The lower BW of PR rats is due to a reduction of white fat tissue, probably caused by an increase in lipolysis or impairment of lipogenesis; both effects could be related to higher catecholaminergic status, as well as to hypoinsulinaemia. To conclude, changes in key hormones which control intermediary metabolism are programmed by maternal protein restriction during lactation, resulting in BW alterations in adult rats.

Short- and long-term effects of maternal nicotine exposure during lactation on body adiposity, lipid profile, and thyroid function of rat offspring

Epidemiological studies show a higher prevalence of obesity in children from smoking mothers and smoking may affect human thyroid function. To evaluate the mechanism of smoking as an imprinting factor for these dysfunctions, we evaluated the programming effects of maternal nicotine (NIC) exposure during lactation. Two days after birth, osmotic minipumps were implanted in lactating rats, divided into: NIC (6 mg/kg per day s.c.) for 14 days; Control - saline. All the significant data were P<0.05 or less. Body weight was increased from 165 days old onwards in NIC offspring. Both during exposure (at 15 days old) and in adulthood (180 days old), NIC group showed higher total fat (27 and 33%). In addition, NIC offspring presented increased visceral fat and total body protein. Lipid profile was not changed in adulthood. Leptinemia was higher at 15 and 180 days old (36 and 113%), with no changes in food intake. Concerning the thyroid status, the 15-days-old NIC offspring showed lower serum-free tri-iodothyronine (FT(3)) and thyroxine (FT(4)) with higher TSH. The 180-days-old NIC offspring exhibited lower TSH, FT(3), and FT(4)). In both periods, liver type 1 deiodinase was lower (26 and 55%). We evidenced that NIC imprints a neonatal thyroid dysfunction and programs for a higher adiposity, hyperleptinemia, and secondary hypothyroidism in adulthood. Our study identifies lactation as a critical period to NIC programming for obesity, with hypothyroidism being a possible contributing factor.

A review: relation between invasiveness and the K1 capsular polysaccharide of Escherichia coli

The conclusions from our studies to date may be summarized as follows. (1) Invasive E. coli strains causing neonatal meningitis are encapsulated. At least 80% of those strains inducing mengitis are K1 and approximately 40% of those strains isolated from infants with septicemia but without meningitis are also K1. Invasiveness is best related to the K1 antigen and not to E. coli O and H antigens. (2) The capsular content of CSF strains is not related to their invasiveness. In contrast to observations reporting higher K capsular polysaccharide content and molecular weight of E. coli invading the renal parenychma as compared with those E. coli confined to the bladder or in the stool, there were no differences among DSF K1 strains. Sepculation as to the mechanism of the invasive properties conferred by acidic capsular polysaccharides may be derived from the literature. Unencapsulated or "rough bacteria" are susceptible to the bactericidal action of agammaglobulinemice sera (15, 53). When injected into precolostral (agammaglobulinemic but complement containing), cesarian-delivered, and antigen-deprived piglets, unencapsulated bacteria are rapidly cleared from the circulation. In contrast, smooth bacteria injected into these same animals circulate without detectable splenic or hepatic clearance, multiply, and result in the death of these animals. The mechanism of the resistance of encapsulated bacteria has been postulated to be due to the inaccessibility of the deep somatic antigen structures capable of activating the alternate complement pathway system. Thus, opsoninization and other host complement-dependent activities may of necessity be antibody mediated for encapsulated bacteria. This complement resistance of encapsulated organisms may be quanititative and studies should be done to determine differences among various K1 E. coli strains. (3) K1 strains are widely prevalent among infants, children, and adults and are quickly transmitted to infants. In most cases the source of the infecting strain in diseased infants is the mother. However, transmission from attendants, demonstrable in our studies, is also a possible mechanism. (4) A protective role of serum anticapsular antibodies in animal models has been demonstrated. Our initial observations indicating low serum K1 antibodies in the general population and the finding that K1 antibodies are predominantly IgM in two animal species studied so far suggest that colostral K1 antibodies may be important in conferring immunity to this disease.

Nicotine exposure affects mother's and pup's nutritional, biochemical, and hormonal profiles during lactation in rats

We have shown that maternal nicotine exposure during lactation has long-lasting effects on body adiposity and hormonal status of rat offspring. Here, we studied the nutritional and hormonal profiles in this experimental model. Two days after birth, osmotic minipumps were implanted in lactating rats divided into two groups: NIC - continuous s.c. infusions of nicotine (6 mg/kg per day) for 14 days and C - saline. Dams and pups were killed at 15 and 21 days of lactation. Body weight and food intake were evaluated. Milk, blood, visceral fat, carcass, and adrenal gland were collected. All the significant data were P<0.05. At the end of nicotine exposure (15 days), dams presented higher milk production, hyperprolactinemia, and higher serum high-density lipoprotein cholesterol (HDL-C). Milk from NIC dams had higher lactose concentration and energy content. After nicotine withdrawal (21 days), dams showed lower food intake and hyperleptinemia. The 15-day-old NIC pups presented higher total body fat, higher HDL-C, serum leptin, serum corticosterone, and adrenal catecholamine content, but lower tyrosine hydroxylase protein levels. The 21-day-old NIC pups had higher body protein content and serum globulin. Thus, maternal nicotine exposure during lactation results in important changes in nutritional, biochemical, and hormonal parameters in dams and offspring. The pattern of these effects is clearly distinct when comparing the nicotine-exposed group to the withdrawal group, which could be important for the programming effects observed previously.

High levels of hybridization between molecular forms of Anopheles gambiae from Guinea Bissau

In the malaria vector Anopheles gambiae Giles sensu stricto, two molecular forms denoted M and S are considered units of incipient speciation within this species. Very low hybrid frequencies and significant genetic differentiation have been found in sympatric M- and S-form populations. We studied the molecular form composition and the degree of genetic differentiation at 15 microsatellites in two samples of An. gambiae collected in two consecutive years from Bissau, Guinea Bissau. High frequencies of M/S hybrids (19-24%) were found in this area. Coincidently, very low levels of genetic differentiation were detected between forms when analysis involved microsatellites mapped at chromosome-3 (mean Fst, 0.000-0.002). The single exception was the X-linked AGXH678, for which high differentiation was measured (Fst, 0.158-0.301). This locus maps near the centromere of chromosome X, a low recombination region in which selection is likely to promote divergence between M and S forms. These results strongly suggest that the degree of isolation between M and S forms, considered the units of incipient speciation within An. gambiae, is not homogenous throughout the species distribution range.

Structure of two fragments of the third cytoplasmic loop of the rat angiotensin II AT1A receptor. Implications with respect to receptor activation and G-protein selection and coupling

The structural bases that render the third intracellular loop (i3) of the rat angiotensin II AT1A receptor one of the cytoplasmic domains responsible for G-protein coupling are still unknown. The three-dimensional structures of two overlapping peptides mapping the entire i3 loop and shown to differently interact with purified G-proteins have been obtained by simulated annealing calculations, using NMR-derived constraints collected in 70% water/30% trifluoroethanol solution. While the NH2-terminal half, Ni3, residues 213-231, adopts a stable amphipathic alpha-helix, extending over almost the entire peptide, a more flexible conformation is found for the COOH-terminal half, Ci3, residues 227-242. For this peptide, a cis-trans isomerization around the Lys6-Pro7 peptide bond generates two exchanging isomers adopting similar conformations, with an alpha-helix spanning from Asn9 to Ile15 and a poorly defined NH2 terminus. A quite distinct structural organization is found for the sequence EIQKN, common to Ni3 and Ci3. The data do suggest that the extension and orientation of the amphipathic alpha-helix, present in the proximal part of i3, may be modulated by the distal part of the loop itself through the Pro233 residue. A molecular model where this possibility is considered as a mechanism for G-protein selection and coupling is presented.

Blockade of the action of nitric oxide in human septic shock increases systemic vascular resistance and has detrimental effects on pulmonary function after a short infusion of methylene blue

To investigate the role of nitric oxide in human sepsis, ten patients with severe septic shock requiring vasoactive drug therapy and mechanical ventilation were enrolled in a prospective, open, non-randomized clinical trial to study the acute effects of methylene blue, an inhibitor of guanylate cyclase. Hemodynamic and metabolic variables were measured before and 20, 40, 60, and 120 min after the start of a 1-h intravenous infusion of 4 mg/kg of methylene blue. Methylene blue administration caused a progressive increase in mean arterial pressure (60 [55-70] to 70 [65-100] mmHg, median [25-75th percentiles]; P<0.05), systemic vascular resistance index (649 [479-1084] to 1066 [585-1356] dyne s-1 cm-5 m-2; P<0.05) and the left ventricular stroke work index (35 [27-47] to 38 [32-56] g m-1 m-2; P<0.05) from baseline to 60 min. The pulmonary vascular resistance index increased from 150 [83-207] to 186 [121-367] dyne s-1 cm-5 m-2 after 20 min (P<0.05). Mixed venous saturation decreased from 65 [56-76] to 63 [55-69]% (P<0.05) after 60 min. The PaO2/FiO2 ratio decreased from 168 [131-215] to 132 [109-156] mmHg (P<0.05) after 40 min. Arterial lactate concentration decreased from 5.1 +/- 2.9 to 4.5 +/- 2.1 mmol/l, mean +/- SD (P<0.05) after 60 min. Heart rate, cardiac filling pressures, cardiac output, oxygen delivery and consumption did not change. Methylene blue administration was safe and no adverse effect was observed. In severe human septic shock, a short infusion of methylene blue increases systemic vascular resistance and may improve myocardial function. Although there was a reduction in blood lactate concentration, this was not explained by an improvement in tissue oxygenation, since overall oxygen availability did not change. However, there was a significant increase in pulmonary vascular tone and a deterioration in gas exchange. Further studies are needed to demonstrate if nitric oxide blockade with methylene blue can be safe for patients with septic shock and, particularly, if it has an effect on pulmonary function.

A Quality by design (QbD) approach on starch-based nanocapsules: A promising platform for topical drug delivery

Exploring novel applications for approved excipients with a history of safe use in therapeutics is a smart strategy to obtain improved pharmaceutical products. The present study aimed at developing a novel starch-based nanoparticulate carrier system (StNC) for topical delivery of lipophilic bioactive molecules. The role of the different factors that affect the particle size distribution and zeta potential of StNC prepared by the emulsification-solvent evaporation method was assessed using a quality by design approach. An optimal formulation was selected and fully characterized in terms of molecular interactions (DSC and FTIR), morphology (TEM and AFM), as well as in vitro and in vivo biological properties, including biological sensitivity/irritation studies performed in human volunteers. Results show the surfactant and lipid contents play a major role in StNC particle size distribution. In addition, all tested formulations presented a zeta potential of ca. +33.6±6.7 mV, indicating a good physical stability, while revealing an excellent compromise between stability, safety and cosmeticity, evidencing that StNC are suitable nanocarriers for topical use. Finally, the design planning methodology has clearly shown its usefulness for optimizing the formulation, being also crucial for the understanding of StNC formation process. The StNC proved to be a promising formulation strategy and a potential nanocarrier for topical lipophilic bioactive molecules.

Pharmacogenetically relevant polymorphisms in Portugal

OBJECTIVE

Most drugs are developed based on data from European-derived 'reference' populations; however, clinically relevant DNA polymorphisms often demonstrate population-specific patterns of allele frequencies. Given that the knowledge of the frequency distribution of functional polymorphisms in a population may guide national planning for selection of therapeutic options, in the present study we examined the allele frequencies of enzymes responsible for drug disposition in Portugal.

PATIENTS & METHODS

Using PCR- and Pyrosequencing-based methods, the current study assessed the frequencies of 15 key polymorphisms from genes encoding enzymes involved in Phases I, II and III of drug metabolism, DNA repair and intracellular metabolism in 135 healthy individuals from Portugal.

RESULTS

Allele frequencies were derived for cytochrome P450 (CYP)2C9*2 (13.2%), CYP2C9*3 (8%), CYP2C19*2 (14%), CYP3A4*1B (7%), CYP3A5*3C (87.5%), glutathione S-transferase (GST)M1*0 (77.9%), GSTP1 313A>G (33%), inosine triphosphatase 94C>A (7%), UDP-glucuronosyltransferase (UGT)1A1*28 (28%), UGT1A1 -3156G>A (23%), ATP-binding cassette (ABC)B1 1236C>T (46%), ABCB1 2677G>A/T (2 and 42%), ABCG2 421C>A (8%), excision repair cross-complementing rodent repair deficiency 2 2251A>C (3%) and thymidylate synthetase 1494del (31%).

CONCLUSION

Although, on the whole, the frequency distributions among the Portuguese fitted the patterns commonly found in other Europeans well, evidence for some degree of African influence was observed. This is the most comprehensive study on pharmacogenetically relevant variations in Portugal to date, and the baseline of pharmacogenetic data might be important for determining policy guidelines for cancer prevention and drug treatments in the Portuguese population.

Effects of tobacco smoke exposure during lactation on nutritional and hormonal profiles in mothers and offspring

Exposure to tobacco smoke is related to changes in energy balance regulation and several endocrine dysfunctions. Previously, we showed that maternal nicotine (the main addictive compound of tobacco) exposure exclusively during lactation affects biochemical profiles in mothers, milk, and pups. As the possible consequences for mothers and offspring of maternal smoking during lactation are still unknown, we evaluated the effects of tobacco smoke exposure on nutritional, biochemical, and hormonal parameters in dams and pups at weaning. After 72 h from birth, lactating rats were divided into two groups: smoke-exposed (S) in a cigarette-smoking machine, 4 × 1 h per day throughout the lactation period without pups; control (C), rats were treated the same as the experimental group but exposed to filtered air. Dams and pups were killed at weaning (21 days of lactation). Body weight and food intake were evaluated. Milk, blood, visceral fat, adrenal, and carcass were collected. S dams showed hyperprolactinemia (+50%), hypoinsulinemia (-40%), hypoleptinemia (-46%), as well as lower triglycerides (-53%) and very low-density lipoprotein cholesterol (-50%). Milk of S dams had higher lactose (+52%) and triglycerides (+78%). S pups presented higher body protein (+17%), lower total (-24%) and subcutaneous fat contents (-25%), hypoglycemia (-11%), hyperinsulinemia (+28%), hypocorticosteronemia (-40%), lower adrenal catecholamine content (-40%), hypertriglyceridemia (+34%), higher high-density lipoprotein cholesterol (+16%), and lower low-density lipoprotein cholesterol (-45%). In conclusion, tobacco smoke exposure leads to changes in nutritional, biochemical, and hormonal parameters in dams and, passively through the milk, may promote several important metabolic disorders in the progeny.

Developmental plasticity in adrenal function and leptin production primed by nicotine exposure during lactation: gender differences in rats

Neonate male rats whose mothers were nicotine-treated during lactation have higher adiposity, hyperleptinemia, and adrenal dysfunction. At adulthood, they still present higher adiposity and hyperleptinemia, but there was no report about their adrenal function. Also, there was no report of this developmental plasticity on females. Here, we evaluated the adrenal function and leptin content in adipocytes and muscle of male and female adult offspring whose mothers were nicotine-treated during lactation. On the 2nd postnatal day (PN2), dams were subcutaneously implanted with osmotic minipumps releasing nicotine (NIC-6 mg/kg/day) or saline for 14 days (12 litters/group and 2 rats/litter). Male and female offspring were killed on PN180. Significant data were p<0.05. Male NIC offspring presented higher adrenal catecholamine content (+ 89%) and TH expression (+ 38%), lower "in vitro" catecholamine release (- 19%), and higher adrenergic β3 receptor (ADRB3, + 59%) content in visceral adipose tissue (VAT). Serum corticosterone was higher (+ 77%) in male NIC group, coherent with the increase of both CRH and ACTH immunostaining in hypothalamus and pituitary, respectively. Leptin content was higher in VAT (+ 23%), which may justify the observed hyperleptinemia. Female NIC offspring presented lower ADRB3 content in VAT (- 39%) and lower leptin content in subcutaneous adipose tissue (SAT) (- 46%), but higher leptin content in soleus muscle (+ 22%), although leptinemia was normal. We evidenced a sex dimorphism in the model of maternal nicotine exposure during lactation. The adrenal function in adult offspring was primed only in male offspring while the female offspring displayed relevant alterations in leptin content on muscle and adipocytes.

Endocrine effects of tobacco smoke exposure during lactation in weaned and adult male offspring

Children from pregnant smokers show more susceptibility to develop obesity in adult life. Previously, we failed to demonstrate a program for obesity in rat offspring only when the mothers were exposed to tobacco smoke during lactation. Here, we studied the short- and long-term effects of smoke exposure (SE) to both dams and their pups during lactation on endocrine and metabolic parameters. For this, we designed an experimental model where nursing rats and their pups were divided into two groups: SE group, exposed to smoke in a cigarette smoking machine (four times/day, from the third to the 21st day of lactation), and group, exposed to filtered air. Pups were killed at 21 and 180 days. At weaning, SE pups showed lower body weight (7%), length (5%), retroperitoneal fat mass (59%), visceral adipocyte area (60%), and higher subcutaneous adipocyte area (95%) with hypoinsulinemia (-29%), hyperthyroxinemia (59%), hypercorticosteronemia (60%), and higher adrenal catecholamine content (+58%). In adulthood, SE offspring showed higher food intake (+10%), body total fat mass (+50%), visceral fat mass (retroperitoneal: 55%; mesenteric: 67%; and epididymal: 55%), and lower subcutaneous adipocyte area (24%) with higher serum glucose (11%), leptin (85%), adiponectin (1.4-fold increase), total triiodothyronine (71%), free thyroxine (57%), TSH (36%), triglycerides (65%), VLDL cholesterol (+66%), and HDL cholesterol (91%) levels and lower corticosteronemia (41%) and adrenal catecholamine content (57%). Our present findings suggest that tobacco SE to both dams and their pups during lactation causes malnutrition in early life that programs for obesity and hormonal and metabolic disturbances in adulthood, only if the pups are submitted to the same smoke environment as the mother.

Binding of C-reactive protein to C-carbohydrate and PC-substituted protein

Human CRP and the CRPs of other species bind Ca2+ ion. After binding of the divalent cation, CRP binds all phosphate monoesters with a stochiometry of one mole per mole of CRP subunit. Replacement of the phosphate monoester group by other acidic groups or by conversion to a phosphodiester markedly diminishes or abolishes the ability to bind. Phosphorylcholine is bound by CRP with much higher affinity than other phosphate monoesters speaking for a second binding site with specificity for the positively charged trimethylammonium group. The distance separating the phosphate from the positively charged group may be relevant. Protein that has been coupled with phosphorylcholine or phosphorylethanolamine is able to precipitate with CRP. Several natural substances including pneumococcal-C polysaccharide which react with CRP have been found to contain phosphorylcholine. In addition CRP has another binding site accounting for its ability to react with depyruvylated type 4 pneumococcal polysaccharide which does not contain phosphate or choline.

LC-MSMS identification of Arabidopsis thaliana heat-stable seed proteins: enriching for LEA-type proteins by acid treatment

Protein identification in systems containing very highly abundant proteins is not always efficient and usually requires previous enrichment or fractionation steps in order to uncover minor proteins. In plant seeds, identification of late embryogenesis abundant (LEA) proteins is often masked by the presence of the large family of storage proteins. LEA-proteins are predicted to play a role in plant stress tolerance. They are highly hydrophilic proteins, generally heat-stable, and correlate with dehydration in seeds or vegetative tissues. In the present work, we analyze the protein composition of heat-stable Arabidopsis thaliana seed extracts after treatment with trichloroacetic acid (TCA). The composition of the proteins that precipitate and those that remain in solution in 3% TCA was analyzed by two different approaches: 1D SDS-PAGE coupled to LC-ESI-MSMS analysis and a gel-free protocol associated with LC-MALDI-MSMS. Our results indicate that treating total heat-soluble extracts with 3% TCA is an effective procedure to remove storage proteins by selective precipitation and this fractionation step provides a soluble fraction highly enriched in Lea-type proteins. The analysis and determination of protein identities in this acid-soluble fraction by MS technology is a suitable system for large-scale identification of Lea-proteins present in seeds.

Do the distribution patterns of polymorphisms at the thiopurine S-methyltransferase locus in sub-Saharan populations need revision? Hints from Cabinda and Mozambique

Genetic data on the thiopurine S-methyltransferase (TPMT) polymorphism were obtained in population samples from Cabinda and Mozambique (located in the western and eastern coasts of sub-Saharan Africa, respectively). The overall frequency of TPMT-deficient alleles was 5.6% in Mozambique and 6.3% in Cabinda. Accordingly, one out of the 103 individuals from Cabinda tested had a genotype associated with TPMT deficiency, yielding a frequency that is threefold higher than heretofore reported in any population. In addition, in both Cabinda or Mozambique, TPMT*8 accounted for a significant proportion of non-functional alleles (nearly 40% in Cabinda). Since the substitution defining TPMT*8 seems to be highly specific of sub-Saharan Africa populations and given the fact it has not been integrated into the set of single nucleotide polymorphisms routinely tested for TPMT, a re-design of molecular screenings should be considered in the future in order to avoid serious underestimates of TPMT deficiency when the enzymatic profiles in populations are unknown.

Intratesticular injection of a zinc-based solution as a contraceptive for dogs

The objective of the present study was to evaluate, by light and transmission electron microscopy, the efficacy of a single intratesticular injection of a novel zinc-based solution, as a contraceptive for male dogs. Fifteen mongrel dogs were assigned to three groups (five dogs/group). Group 1, the control group, which consisted of animals ranging from 8 mo to 4 yr, was injected with saline solution. Group 2, which consisted of animals ranging from 8 mo to 1 yr old and Group 3, animals ranging from 2 to 4 yr old, were injected with a zinc-based solution (0.2-1.0mL; volume based on testicular width). There were no histopathological changes detected in testes from control dogs. Histological examination of treated groups revealed degeneration, vacuolation, fewer germ cells, formation of multinucleated giant cells, and a lack of elongated spermatids in atrophic seminiferous tubules. Leydig cells had varying degrees of lipid degeneration and necrosis. The majority of seminiferous tubules in all zinc-treated dogs were lined only by Sertoli cells, which were vacuolated. Ultrastructure of testis of treated groups had degenerate Sertoli and Leydig cells, characterized by numerous mitochondria with the lack of a matrix and agglomeration of lysosomal bodies. The cytoplasm of elongated spermatids was characterized by tubules of hyperplastic and hypertrophic smooth endoplasmic reticulum and numerous Golgi apparati. Round spermatids in Golgi phase had lysis of acrosomal vesicles. The degree of histological changes suggested irreversibility. In conclusion, intratesticular injection of a zinc-based solution effectively impaired spermatogenesis.

First observation of the doubly charmed baryon Xi(+)(cc)

We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.

Thyroid function and body weight programming by neonatal hyperthyroidism in rats - the role of leptin and deiodinase activities

Several authors have shown that secondary hypothyroidism was programed by neonatal thyroxine (T4) treatment. However, the associated changes of body weight (BW) were less studied, especially those related to the body fat proportion. Here, we have evaluated the effect of neonatal thyroxine treatment on BW, fat proportion, serum leptin, and thyroid function of 60-day-old rats. Wistar rats were treated with thyroxine (50 microg/100 g BW, ip) (T) or saline (S), during the first 10 days of life. BW, nose-rump length (NRL), and food consumption were monitored for 60 days, when the animals were sacrificed. Thyroid function was evaluated by thyroid radioiodine uptake (RAIU), serum T3, T4, TSH, and liver mitochondrial alpha-glycerophosphate dehydrogenase (mGPD) and type 1 and 2 deiodinases (D1 and D2) activities, which are thyroid hormone-dependent enzymes. T animals showed lower food intake, BW and NRL, but higher total fat mass (+33%) and serum leptin (+46%). They also showed lower serum T3 (-23%), T4 (-32%), TSH (-36%), RAIU (-29%) and mGPD activity (-22%). Hypothalamic and pituitary D2 activities were higher (+24% and 1.4 fold, respectively), while brown adipose tissue (BAT) D2 and skeletal muscle D1 activities were lower (-30% and -62%, respectively). Thus, neonatal hyperthyroidism programs for a higher fat proportion and hyperleptinemia, which can explain the lower food intake. The TH-dependent enzymes activities changed accordingly, except for the decrease in BAT D2, which may be due the role played by the hyperleptinemia. Finally, the decrease in peripheral deiodination may contribute to a lower me-tabolic rate that may increase the adiposity.

Neonatal nicotine exposure alters leptin signaling in the hypothalamus-pituitary-thyroid axis in the late postnatal period and adulthood in rats

AIMS

Postnatal nicotine exposure causes precocious primary hypothyroidism and programs for overweight, hyperleptinemia and secondary hypothyroidism in adulthood. As leptin and thyroid hormones share the ability to increase energy expenditure, we studied the effects of maternal nicotine exposure during lactation on the leptin signaling in the hypothalamus-pituitary-thyroid axis of suckling and adult offspring.

MAIN METHODS

Two days after delivery, osmotic minipumps were implanted in lactating rats, and nicotine (NIC, 6 mg/kg/day s.c.) or saline (C) was administered for 14days. Offspring were killed at 15 and 180 days-old. Proteins belonging to leptin signaling were analyzed by Western blot. Significant differences had p<0.05.

KEY FINDINGS

In the hypothalamus, NIC offspring showed higher OB-R and pSTAT-3 content (+58%,+1.34x) at 15 days, and lower OB-R, JAK-2 and pSTAT-3 (-61%, -42%, -56%) at 180 days. In the pituitary gland, NIC offspring showed lower JAK-2 content (-52%) at 15 days, but no differences in adulthood. In the thyroid gland, the NIC group presented lower OB-R, JAK-2 and STAT-3 (-44%, -50%, -47%) and higher pSTAT-3 expression (+80%) at 15 days. At 180 days-old, NIC offspring presented higher thyroid OB-R (+1.54x) and lower pSTAT-3 content (-34%).

SIGNIFICANCE

Neonatal primary hypothyroidism induced by maternal nicotine exposure during lactation may be partially explained by decreased leptin signaling in the thyroid, though the early stimulation of the central leptin pathway did not prevent the thyroid dysfunction. Long-term effects of postnatal nicotine exposure on leptin signaling in the hypothalamus and thyroid appear to involve central and peripheral leptin resistance in adulthood.

Vascular effects and electrolyte homeostasis of the natriuretic peptide isolated from Crotalus oreganus abyssus (North American Grand Canyon rattlesnake) venom

Crotalus oreganus abyssus is a rattlesnake that is usually found in the Grand Canyon, United States of America. Knowledge regarding the composition of C. o. abyssus venom is scarce. New natriuretic peptides (NPs) have been isolated and characterized from the venoms of members of the Crotalinae family. The NP family comprises three members, ANP (atrial natriuretic peptide), BNP (b-type natriuretic peptide) and CNP (c-type natriuretic peptide), and has an important role in blood pressure regulation and electrolyte homeostasis. The aim of the present study was to characterize a novel natriuretic-like peptide (Coa_NP2), isolated from C. o. abyssus venom. The Coa_NP2 presents an average molecular mass of 3419.88Da (theoretical average molecular mass 3418.94Da, monoisotopic molecular mass 3416.66Da and theoretical PI 7.78) and its amino acid sequence presents the loop region that is characteristic of natriuretic peptides. The peptide has 32 amino acids and its complete sequence is SYGISSGCFGLKLDRIGTMSGLGCWRLLQDSP. Coa_NP2 is a natriuretic peptide of the ANP/BNP-like family, since the carboxyterminal region of CNP has its own NP domain. We demonstrate, herein, that Coa_NP2 produces a dose-dependent decrease in mean arterial pressure in rats, followed by significant increases in concentrations of markers of nitric oxide formation measured in the plasma and vasorelaxation in a thoracic aortic ring bath. The structural and biological aspects confirm Coa_NP2 as a new natriuretic peptide, isolated from snake venom.

Dual effect of advanced glycation end products in pancreatic islet apoptosis

BACKGROUND

Loss of β-cell function hastens deterioration of metabolic control in type 2 diabetes patients. Besides amyloid deposit and glucolipotoxicity, advanced glycation end products (AGEs) acting through their receptors (RAGE) seem to contribute to this process by promoting islet apoptosis. In order to investigate the role of AGEs in β-cell deterioration, we evaluated the temporal and dose effects of AGE compounds on apoptosis rate, reactive oxygen species generation and expression of pro-apoptotic and anti-apoptotic genes in cultured islets.

METHODS

Rat pancreatic islets were exposed or not for 24, 48, 72 and 96 h to albumin modified by glycoaldehyde. Apoptosis, reactive oxygen species and superoxide content and NADPH oxidase activity were evaluated as well as RNA expression of the genes Ager (codes for RAGE), Bax, Bcl2 and Nfkb1.

RESULTS

In 24 and 48 h, glycoaldehyde elicited a decrease in apoptosis rate in comparison with the control condition concomitantly with a reduction in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In contrast, after 72 and 96 h, glycoaldehyde promoted an increase in apoptosis rate concomitantly with an increase in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In 24 h, glycoaldehyde elicited a decrease in the islet content of reactive oxygen species, whereas after 48 and 72 h, it promoted an opposite effect, increasing superoxide generation. The NADPH oxidase inhibitor VAS2870 attenuated superoxide production, implicating NADPH oxidase as an important source of reactive oxygen species in islets exposed to AGEs.

CONCLUSIONS

Albumin modified by glycoaldehyde exerted a dual effect in cultured pancreatic islets, being protective against apoptosis after short exposure but pro-apoptotic after prolonged exposure.

Spanish human proteome project: dissection of chromosome 16

The Chromosome 16 Consortium forms part of the Human Proteome Project that aims to develop an entire map of the proteins encoded by the human genome following a chromosome-centric strategy (C-HPP) to make progress in the understanding of human biology in health and disease (B/D-HPP). A Spanish consortium of 16 laboratories was organized into five working groups: Protein/Antibody microarrays, protein expression and Peptide Standard, S/MRM, Protein Sequencing, Bioinformatics and Clinical healthcare, and Biobanking. The project is conceived on a multicenter configuration, assuming the standards and integration procedures already available in ProteoRed-ISCIII, which is encompassed within HUPO initiatives. The products of the 870 protein coding genes in chromosome 16 were analyzed in Jurkat T lymphocyte cells, MCF-7 epithelial cells, and the CCD18 fibroblast cell line as it is theoretically expected that most chromosome 16 protein coding genes are expressed in at least one of these. The transcriptome and proteome of these cell lines was studied using gene expression microarray and shotgun proteomics approaches, indicating an ample coverage of chromosome 16. With regard to the B/D section, the main research areas have been adopted and a biobanking initiative has been designed to optimize methods for sample collection, management, and storage under normalized conditions and to define QC standards. The general strategy of the Chr-16 HPP and the current state of the different initiatives are discussed.

Three dimensional anatomy of the human nucleus accumbens

BACKGROUND

The Nucleus accumbens (Acc) is the main structure of the ventral striatum. It acts as a motor-limbic interface, being involved in emotional and psychomotor functions, frequently disturbed in neuropsychiatric disorders such as obsessive compulsive disorder and addiction. Most of the studies concerning the Acc were made in animals and those performed in humans are contradictory. Nevertheless, it has become a target for stereotactic deep brain stimulation for some of those diseases, when refractory to medical treatment. Previous studies performed by our group have established the localization, limits and dimensions of the human Acc and its stereotactic coordinates. Now it is our purpose to perform the Acc anatomical three-dimensional (3D) reconstruction in order to clarify its shape and topography and to render this nucleus a safer target for stereotactic procedures.

METHODS

Anatomical coronal slicing of ten Acc from human brains was performed, perpendicular to the anterior commissure-posterior commissure line and to the midline; then the Acc contours were traced and its dimensions and 3D stereotactic coordinates measured, on each slice. Finally a 3D computerized model was created.

RESULTS

The human Acc was identified as a distinct brain structure, with clear-cut limits on its posterior half. It lies parallel to the midline, descends caudally, and progresses from a globose to a flattened and dorsolateral concave shape. Its main expression is subcomissural.

CONCLUSION

This study defined more accurately the 3D anatomy of the human Acc, providing new tools for stereotactic procedures.

Higher white adipocyte area and lower leptin production in adult rats overfed during lactation

Litter size reduction during lactation is a good model for childhood obesity since it induces overnutrition and programming for obesity at adulthood. Adult offspring develop higher fat mass content, hyperinsulinemia and insulin resistance, hypertension, lower HDL cholesterol, hyperphagia, and leptin resistance. Leptin resistance is often associated with hyperleptinemia. Although we observed higher SOCS3 and lower STAT3 in the hypothalamus of rats raised in small litters featuring a central leptin resistance, they showed unexpected normoleptinemia at 180 days old. Then, to clarify why early overfed rats did not develop hyperleptinemia when adult, we studied the leptin production by the visceral and subcutaneous adipose tissue and skeletal muscle as well as the morphology in the 2 different fat depots. To induce EO, litter size was reduced to 3 pups/litter (SL group) on the 3 (rd) day of life. In controls (NL group), litter size was adjusted to 10 pups/litter. Rats were killed at 180 days old. The programming of adipose tissue morphology by early overnutrition is specific between the different fat depots with hypertrophy only in the visceral compartment. In addition, the visceral adipocyte showed lower leptin content that may indicate a reduced leptin synthesis. These data suggest that adipocytes from SL rats are dysfunctional, since a higher leptin production in larger adipose cells is expected. In conclusion, postnatal nutrition is determinant for future leptin production by different fat depots as well as adipocyte morphology. These changes seem to be related to the severity of obesity and its metabolic consequences.