Hydrogen peroxide promotes gastric motility in the newborn rat.

BACKGROUND: When compared with infant formula, human milk enhances gastric emptying in preterm infants. Hydrogen peroxide (H2O2) is present in large quantities in human milk that has an antimicrobial role for the mother and infant. In vitro adult rat studies suggest that H2O2 facilitates gastric motor contraction. Hypothesizing that H2O2 enhances gastric motility, we investigated its effects on the newborn rat stomach tissue. METHODS: Rat newborn and adult gastric fundic segments, or their smooth muscle cells, were used to evaluate the muscle response to H2O2 exposure. Tissue expression of Rho kinase 2 (ROCK-2; Western blot), its catalase activity, and H2O2 content (Amplex Red) were measured. H2O2 gastric mucosal diffusion was evaluated with Ussing chambers. RESULTS: In both newborn and adult rats, H2O2 induced gastric muscle contraction and this response was attenuated by pre-incubation with the antioxidant melatonin. H2O2 passively diffused across the gastric mucosa. Its effect on the muscle was modulated via ROCK-2 activation and inhibited by melatonin. CONCLUSION: H2O2, at a concentration similar to that of human milk, promotes gastric motility in the rat. To the extent that the present findings can be clinically extrapolated, the human milk H2O2 content may enhance gastric emptying in neonates.

Cardiometabolic Disorders in Psoriatic Disease.

PURPOSE OF REVIEW: Patients with psoriasis and psoriatic arthritis, collectively termed psoriatic disease (PsD), are at an increased risk of developing cardiovascular diseases (CVD). The purpose if this manuscript is to review recent evidence about the epidemiology and underlying mechanisms of CVD in psoriatic patients and approaches to improve the management of these comorbidities. RECENT FINDINGS: Studies have shown that CVD risk is independent of traditional cardiovascular risk factors and is related to the systemic inflammatory nature of PsD. The use of surrogate markers, such as imaging of subclinical atherosclerosis, allows detection of patients at high cardiovascular risk before the occurrence of clinical events. These modalities could be clinically useful as clinical cardiovascular risk algorithms, such as the Framingham Risk Score, and have been shown to underestimate the actual cardiovascular risk in patients with PsD. Additional challenges related to the management of CVD in psoriatic patients include the underdiagnosis and undertreatment of traditional cardiovascular risk factors in rheumatology, dermatology and primary care setting. Effective measures used to control PsD, such as tumour necrosis factor inhibitors and methotrexate, has been associated with reduced cardiovascular risk in psoriatic patients. These findings highlight the importance of controlling disease activity as potential target that could lead to reduced cardiovascular risk. Together this highlights the importance of optimization of cardiovascular risk stratification and management of cardiovascular risk factors in patients with PsD.

Gastric and pyloric sphincter muscle function and the developmental-dependent regulation of gastric content emptying in the rat.

Feeding intolerance is a common issue in the care of preterm neonates. The condition manifests as delayed emptying of gastric contents and represents a therapeutic challenge, since the factors accounting for its manifestations are unknown. The main goal of this study was to comparatively investigate the age-related function of rat gastric and pyloric smooth muscle and their putative regulators. We hypothesized that a reduced gastric muscle contraction potential early in life contributes to the delayed gastric emptying of the newborn. Newborn and adult rat gastric (fundus) and pyloric sphincter tissues were comparatively studied in vitro. Shortening of the tissue-specific dissociated smooth muscle cell was evaluated, and expression of the key regulatory proteins Rho-associated kinase 2 and myosin light chain kinase was determined. Gastric and pyloric smooth muscle cell shortening was significantly greater in the adult than the respective newborn counterpart. Expression of myosin light chain kinase and Rho-associated kinase 2 was developmentally regulated and increased with age. Pyloric sphincter muscle expresses a higher neuronal nitric oxide synthase and phosphorylated vasodilator-stimulated phosphoprotein content in newborn than adult tissue. Compared with later in life, the newborn rat gastropyloric muscle has a Ca(2+)-related reduced potential for contraction and the pyloric sphincter relaxation-dependent modulators are overexpressed. To the extent that these rodent data can be extrapolated to humans, the delayed gastric emptying in the newborn reflects reduced stomach muscle contraction potential, as opposed to increased pyloric sphincter tone.

Value of Carotid Ultrasound in Cardiovascular Risk Stratification in Patients With Psoriatic Disease.

OBJECTIVE: This study aimed to assess whether subclinical atherosclerosis, as evaluated by carotid ultrasound, could predict incident cardiovascular events (CVEs) in patients with psoriatic disease (PsD) and determine whether incorporation of imaging data could improve CV risk prediction by the Framingham Risk Score (FRS). METHODS: In this cohort analysis, patients with PsD underwent ultrasound assessment of the carotid arteries at baseline. The extent of atherosclerosis was assessed using carotid intima-media thickness (CIMT) and total plaque area (TPA). Incident CVEs (new or recurrent) that occurred following the ultrasound assessment were identified. The association between measures of carotid atherosclerosis and the risk of developing an incident CVE was evaluated using Cox proportional hazards models, with adjustment for the FRS. RESULTS: In total, 559 patients with PsD were assessed, of whom 23 had incident CVEs ascertained. The calculated rate of developing a first CVE during the study period was 1.11 events per 100 patient-years (95% confidence interval [95% CI] 0.74-1.67). When analyzed separately in Cox proportional hazards models that were controlled for the FRS, the TPA (hazard ratio [HR] 3.74, 95% CI 1.55-8.85; P = 0.003), mean CIMT (HR 1.21, 95% CI 1.03-1.42; P = 0.02), maximal CIMT (HR 1.11, 95% CI 1.01-1.22; P = 0.03), and high TPA category (HR 3.25, 95% CI 1.18-8.95; P = 0.02) were each predictive of incident CVEs in patients with PsD. CONCLUSION: The burden of carotid atherosclerosis is associated with an increased risk of developing future CVEs. Combining vascular imaging data with information on traditional CV risk factors could improve the accuracy of CV risk stratification in patients with PsD.