Arginase inhibition by (-)-Epicatechin reverses endothelial cell aging

Endothelial dysfunction (EnD) occurs with aging and endothelial nitric oxide (NO) production by NO synthase (NOS) can be impaired. Low NO levels have been linked to increased arginase (Ar) activity as Ar competes with NOS for L-arginine. The inhibition of Ar activity can reverse EnD and (-)-epicatechin (Epi) inhibits myocardial Ar activity. In this study, through in silico modeling we demonstrate that Epi interacts with Ar similarly to its inhibitor Norvaline (Norv). Using in vitro and in vivo models of aging, we examined Epi and Norv-inhibition of Ar activity and its endothelium-protective effects. Bovine coronary artery endothelial cells (BCAEC) were treated with Norv (10 μM), Epi (1 μM) or the combination (Epi + Norv) for 48 h. Ar activity increased in aged BCAEC, with decreased NO generation. Treatment decreased Ar activity to levels seen in young cells. Epi and Epi + Norv decreased nitrosylated Ar levels by ~25% in aged cells with lower oxidative stress (~25%) (dihydroethidium) levels. In aged cells, Epi and Epi + Norv restored the eNOS monomer/dimer ratio, protein expression levels and NO production to those of young cells. Furthermore, using 18 month old rats 15 days of treatment with either Epi (1 mg/kg), Norv (10 mg/kg) or combo, decreased hypertension and improved aorta vasorelaxation to acetylcholine, blood NO levels and tetra/dihydribiopterin ratios in cultured rat aortic endothelial cells. In conclusion, results provide evidence that inhibiting Ar with Epi reverses aged-related loss of eNOS function and improves vascular function through the modulation of Ar and eNOS protein levels and activity.

Comparison of Mycoplasma hyopneumoniae and porcine circovirus 2 commercial vaccines efficacy when applied separate or combined under experimental conditions

Background

Mycoplasma hyopneumoniae (Mhyo) and Porcine circovirus 2 (PCV-2) are two of the most significant infectious agents causing economic losses in the weaning to slaughter period. Due to their similar vaccination age, the objective of this study was to assess the efficacy of two already existing Mhyo (Hyogen®) and PCV-2 (Circovac®) vaccines when administered separately or combined (RTM) by means of Mhyo or PCV-2 experimental challenges.

Results

Seven groups of animals were included in the study, being three of them challenged with PCV-2, three with Mhyo and one composed of non-challenged, non-vaccinated pigs. Within each experimental challenge, non-vaccinated (NV) groups were compared with double vaccinated groups using the commercial products separated (VS) or combined (VC). Both vaccinated groups showed significant differences for most parameters measured regarding PCV-2 (serology, percentage of infected animals and viral load in tissues) and Mhyo (serology and gross lesions) when compared to NV groups. VS and VC offered similar results, being only significantly different the PCV-2 antibody values at different time points (higher in the VS group) of the study, although not at the termination day (21 days post-PCV-2 inoculation).

Conclusion

The present study expands the knowledge on the possibility of using two separate Mhyo and PCV-2 commercial vaccines as a RTM product, which offered equivalent virological, immunological and pathological outcomes as compared to these vaccines when used by separate.

(-)-Epicatechin induced reversal of endothelial cell aging and improved vascular function: underlying mechanisms

The consumption of cocoa products rich in (-)-epicatechin is associated with reduced cardiovascular risk and improved vascular function. However, little is known about (-)-epicatechin's effects on aged endothelium. In order to characterize the health restoring effects of (-)-epicatechin on aged endothelium and identify the underlying mechanisms, we utilized high passage number (i.e. aged) bovine coronary artery endothelial cells and aortas of 3 and 18 month old rats. We evaluated cell senescence (β-galactosidase), nitric oxide (NO) production through the endothelial nitric oxide synthase pathway, mitochondria related endpoints, citrate synthase activity and vascular relaxation. Cells were treated with water or (-)-epicatechin (1 μM) for 48 h and rats orally with either water or (-)-epicatechin (1 mg kg-1 day-1) for 15 days. Senescence associated β-galactosidase levels doubled in aged cells while those treated with (-)-epicatechin only evidenced an ∼40% increase. NO levels in cells decreased by ∼33% with aging and (-)-epicatechin normalized them. Endothelial nitric oxide synthase phosphorylation levels paralleled these results. Aging increased total protein and synthase acetylation levels and (-)-epicatechin partially restored them to those of young cells by stimulating sirtuin-1 binding to the synthase. Phosphorylated sirtuin-1, mitofilin, oxidative phosphorylation complexes and transcriptional factor for mitochondria were reduced by ∼40% with aging and were restored by (-)-epicatechin. (-)-Epicatechin enhanced acetylcholine induced aged aorta vasodilation and stimulated NO levels while reducing blood pressure. In conclusion, (-)-epicatechin reverses endothelial cell aging and restores key control elements of vascular function. These actions may partly explain the epidemiological evidence for the beneficial effects of cocoa consumption on the incidence of cardiac and vascular diseases.

86 Difficulty of Transfer of In Vivo-Derived Bovine Embryos and Route of Administration of Flunixin Meglumine at the Time of Transfer may Affect Pregnancy Rate

Recipient handling during embryo transfer (ET) induces prostaglandin F2α (PGF2α) production in 2 periods: an early transient and rapid increase around the time of ET, followed by another 2 to 4 h later. This PGF2α is associated with embryonic loss during early gestation by affecting both the embryo and the corpus luteum. To control this, antiprostaglandins such as flunixin meglumine (FM) have been applied IM at the time of ET with varying results. In such studies, the interaction of IM administration of FM and difficulty of transfer has not always been evaluated, possibly confusing the interpretation of the results. Furthermore, IV FM injection at ET and its relationship with pregnancy rates (PR) has not been determined. The objectives were (1) to determine the relationship between difficulty of ET and PR; and (2) to evaluate the efficacy of IM v. IV FM on pregnancy outcomes. One hundred and ten crossbred (Bos taurus × Bos indicus) heifers (18-24 months old) from 3 farms were used as recipients. Two evaluation systems of ET difficulty were used: (1) duration of transfer (objective determination of the elapsed time measured in seconds between the introduction of the catheter and embryo release), and (2) level of difficulty experienced by the practitioner (subjective determination; 1 = minimum and 2 = medium to extreme manipulation). Quality 1 and 2 fresh embryos from superovulated cows were transferred by the same practitioner. At ET, recipients were randomly divided into 3 groups: (1) Control (no treatment, n = 31); (2) FM-IM (n = 39): injected IM with 2.2 mg kg−1 FM at ET; and (3) FM-IV (N = 40): injected with 2.2 mg kg−1 FM IV at ET. Pregnancy was diagnosed at 30 to 40 and 60 to 90 days after ET. Spearman’s test was performed to determine the correlation between duration and difficulty at ET and Chi-square test was used to compare PR. The mean duration of transfer for all heifers was 62.3 ± 57.5 s (11 to 357 s; median: 44.5 s). There was a high correlation (0.8; P < 0.001) between the ET difficulty evaluation systems. Overall, ET difficulty 1 had higher PR than ET difficulty 2 (64.2 v. 40.7; P = 0.013). The PR was significantly improved (P < 0.01) in the FM-IV group (75 and 70% at 30 and 60 days after ET) compared with control (45.2 and 32.3%) and FM-IM (33.3 and 30.7%). In conclusion, results indicate that the difficulty of transfer affects PR achieved following the transfer of in vivo-derived bovine embryos. Treatment with FM-IV following transfer resulted in significantly higher PR compared with control and FM-IM recipients. The IV injection of FM may antagonize the very early and transient increase of PGF2α caused by genital tract manipulation (even gently performed) at embryo transfer. Further research is necessary to confirm the results of the present study.

The association of geographic atrophy and decreased renal function in patients with age-related macular degeneration

PurposeThe purpose of the study was to investigate the association between area and presence of geographic atrophy (GA) and renal function, as measured by glomerular filtration rate (GFR).Patients and methodsWe retrospectively identified patients aged 50-90 years who were assigned an ICD-9 diagnosis code for age-related macular generation (AMD) between January 2012 and January 2016. Patients met inclusion criteria if they had at least one macular spectral domain optical coherence tomography volume scan, one provider note, and one GFR value in the electronic medical record. Images were evaluated for the presence of GA, area of GA, drusen, and subretinal drusenoid deposits (SDD) and for subfoveal choroidal thickness (CTh) by standard criteria. Imaging findings were correlated with the most recent GFR from the patient's chart.ResultsWe identified 107 patients who met our inclusion criteria (mean age=74 years, range 50-90 years). Overall, we found a significant correlation between the presence of GA and reduced GFR (P=0.002), which was maintained even after accounting for age and other confounders. No association between GFR and GA area was found. CTh was significantly lower in patients with GA (P=0.038) and those with decreased GFR (P=0.004). Within the SDD-positive population, GA was associated with reduced GFR (P=0.007) but only trended toward significance after controlling for age.ConclusionOur study findings demonstrate an association between impaired renal function and the presence, but not area, of GA within an AMD population. These findings may shed light on common pathogenic mechanisms for these two diseases.

The effects of (-)-epicatechin on endothelial cells involve the G protein-coupled estrogen receptor (GPER)

We have provided evidence that the stimulatory effects of (-)-epicatechin ((-)-EPI) on endothelial cell nitric oxide (NO) production may involve the participation of a cell-surface receptor. Thus far, such entity(ies) has not been fully elucidated. The G protein-coupled estrogen receptor (GPER) is a cell-surface receptor that has been linked to protective effects on the cardiovascular system and activation of intracellular signaling pathways (including NO production) similar to those reported with (-)-EPI. In bovine coronary artery endothelial cells (BCAEC) by the use of confocal imaging, we evidence the presence of GPER at the cell-surface and on F-actin filaments. Using in silico studies we document the favorable binding mode between (-)-EPI and GPER. Such binding is comparable to that of the GPER agonist, G1. By the use of selective blockers, we demonstrate that the activation of ERK 1/2 and CaMKII by (-)-EPI is dependent on the GPER/c-SRC/EGFR axis mimicking those effects noted with G1. We also evidence by the use of siRNA the role that GPER has on mediating ERK1/2 activation by (-)-EPI. GPER appears to be coupled to a non Gαi/o or Gαs, protein subtype. To extrapolate our findings to an ex vivo model, we employed phenylephrine pre-contracted aortic rings evidencing that (-)-EPI can mediate vasodilation through GPER activation. In conclusion, we provide evidence that suggests the GPER as a potential mediator of (-)-EPI effects and highlights the important role that GPER may have on cardiovascular system protection.

Activation of upregulated angiotensin II type 2 receptors decreases carotid pulse pressure in rats with suprarenal abdominal aortic coarctation

Our aim was to determine whether angiotensin type 2 receptors (AT2R) are involved in the depression of carotid pulse pressure (PP) in rats with suprarenal aortic coarctation (SrC). We tested the effects of losartan, PD123319, and CGP42112 on PP in SrC and Sham-operated anesthetized rats. PP increased in SrC rats. Neither losartan nor PD123319 affected PP in SrC and Sham-operated rats. CGP42112 reduced PP, in SrC rats, combined with losartan. Moreover, PD123319 blocked this effect. AT2R protein increased in the thoracic aortas of SrC rats. Thus, upregulated AT2R stimulation by CGP42112 mediates depression of PP in rats under pressure overloading.

Leptin mediated ObRb receptor increases expression of adhesion intercellular molecules and cyclooxygenase 2 on murine aorta tissue inducing endothelial dysfunction

There are several reports showing that hyperleptinemia positively correlates with atherogenic process including promotion of platelet aggregation, thrombosis, and production of inflammatory cytokines. Thereby endothelial dysfunction takes place and underlies metabolic and vascular alterations that contribute to the development of both cardiovascular disease and type 2 diabetes. It has been also proposed that endothelial dysfunction may antecede the development of insulin resistance and diabetes. Endothelial cells participate in vasoregulation by the modulation of nitric oxide production and prostaglandin; in addition these cells are major vector in angiogenesis and recruitment of leukocytes and adhesion molecules. Nevertheless mechanisms underlying vascular dysfunction remain to be fully elucidated. This experiment in vitro revealed that the addition of leptin to cultivated endothelial cells elicited a significant molecular expression of both COX 2 and ICAM-1: in addition, the response showed a positive relationship with leptin concentration and the time of incubation. Thus, it may be suggested that leptin acts directly on the endothelium by activating its specific receptor which in turn initiates the molecular response related with the production of factors involved in the inflammatory response. Alterations on prostaglandins and recruiting molecules of adhesion are relevant stages of the endothelial damage.

[Our experience in endourology]

Exposition of the experience accrued over 8 years in endo-urological procedures performed to 303 patients divided in 2 groups: Lithiasic (Group I) and Non-lithiasic (Group II) patients. Ninety-two (92) percutaneous nephrostomies in 69 patients and 235 ureteroscopies in 234 patients were accomplished, removing 324 calculi and resolving other obstructive conditions. The rate of success was 85% and 98% for the percutaneous nephrostomies and ureteroscopies, respectively. Complications were reported in 7 patients after percutaneous nephrostomy and in 14 patients during ureteroscopy. Most of these complications resolved with the use of endoscopic techniques except in two patients who required open surgery. There were no deaths in the present series. The advantages of applying this technique over the conventional one are discussed.

Differential clinical and epidemiological features in children with Campylobacter diarrhoea, mixed-agent diarrhoea and Campylobacter diarrhoea plus parenteral infections

A prospective study of 111 young Peruvian children with Campylobacter jejuni diarrhoea showed that it behaves as an endemic enterotoxigenic-like, waterborne, milkborne, and zoonotic disease. Although there were no definite differential features between pure C. jejuni diarrhoea, mixed-agent diarrhoea, and C. jejuni diarrhoea plus parenteral infections, children with C. jejuni diarrhoea plus parenteral infections were all inpatients, were more frequently malnourished and more frequently exhibited systemic symptoms. Campylobacter jejuni associated with other enteric pathogens did not seem to act synergistically as the disease was not particularly severe in this group.

Acute diarrhoea and Campylobacter in Peruvian children: a clinical and epidemiologic approach

A study performed on Peruvian children < 10 years of age and their controls showed that Campylobacter jejuni is a leading cause of diarrhoea. Infants 1 year old or younger were the most affected. The disease was usually moderately severe, although > 50 per cent of patients required i.v. fluid therapy. Campylobacter was also more frequent in malnourished patients, who come from socio-economically deprived groups, with overcrowding, poor sanitation, and frequent contact with domestic birds and animals. The seasonal behaviour suggests that diarrhoea caused by Campylobacter is endemic in this area.

In-situ Titration of Initiator-Consuming Impurities in Solution Anionic Polymerization

An in situ titration of initiator-consuming impurities in amonic polymerizations, using 1,10-phenantroline as an indicator, was developed. The results show that even when impurities are present, it is possible to destroy them prior to the initiation of the polymerization reaction and achieve a better control of molecular weights by adding accurate known quantities of initiator.

Occult blood and fecal leukocytes as screening tests in childhood infectious diarrhea: an old problem revisited

During a 24-month period 446 children with diarrhea and 16 controls had examination of their stools for leukocytes and for occult blood. Fecal leukocytes were found in 36, 16 and 18% of children with Salmonella-Shigella-Campylobacter, rotavirus or enterotoxigenic Escherichia coli, or cryptosporidial diarrhea, respectively. Similarly 43, 39 and 38% of these groups, respectively, as well as 13% of controls had occult blood. Notably 70% of 10 Shigella cases had fecal leukocytes. In 166 children with mixed pathogens leukocytes were seen in 27 and 8% of children with Salmonella-Shigella-Campylobacter or noninvasive pathogen, respectively. Likewise 44 and 18% of these groups had occult blood. Agreement between both tests being positive was poor, the highest result being 50% for Shigella. Dysentery combined with both tests positive was associated with 15 (88%) cases of invasive agents present in stool cultures, and combination of dysentery with fecal leukocytes was associated with 21 (72%) cases of invasive agents recovered. The results of these tests should be interpreted in the context of the clinical situation. A combined clinical-epidemiologic and screening tests-based approach to infectious diarrhea of childhood is suggested.

[Celiac disease in adolescents]

Nutritional status, sexual maturation and intestinal absorption were assessed in 16 adolescent celiac patients (12 females) at ages 12 and 18 year. Weight/age, height/age and weight/height were 75.5% (51.6-94.8), 90.3% (76.8-104.6) and 99.1% (76.3-112.9) at 12 years and 85.6% (64.0-105.2), 93.8% (85.9-101.2) and 110% (76.5-121.9) at 18 years of age, respectively. Sexual maturation (Tanner) was at stage I in 31%, and at stage II in 43.7% of patients at age 12 years and it had reached maturity in 75% of them at 18 years. Menarche occurred between 12 and 14 years of age, except in 3 patients in whom it was retarded. Mean serum carotene levels were 125 and 108.5 ug/dl at ages 12 and 18 years respectively. Delayed weight and height progress in this particular group of patients might be explained by low socio-economic conditions, late diagnosis, and poor adherence to gluten-free diet.