Cyclic vomiting syndrome: in vitro nitric oxide and interleukin-6 release by esophageal and gastric mucosa

Oxidative stress and motion sickness in one crew during competitive offshore sailing

Competitive Offshore Ocean Sailing is a highly demanding activity in which subjects are exposed to psychophysical stressors for a long time. To better define the physiological adaptations, we investigated the stress response of subjects exposed to 3-days long ocean navigation with disruption of circadian rhythms. 6 male subjects were involved in the study and provided urine and saliva samples before setting sail, during a single day of inshore sailing, during 3-days long ocean navigation, and at the arrival, to measure oxidative stress, cortisol, nitric oxide metabolites (NOx) and metabolic response. Motion Sickness questionnaires were also administered during the navigation. The crew suffered a mean weight loss of 1.58 kg. After the long navigation, a significant increase in ROS production and decrease in total antioxidant capacity and uric acid levels were observed. Lipid peroxidation, NO metabolites, ketones, creatinine, and neopterin levels were also increased. Furthermore, a significant increase in cortisol levels was measured. Finally, we found a correlation between motion sickness questionnaires with the increase of NOx, and no correlation with cortisol levels. Physical and psychological stress response derived from offshore sailing resulted in increased oxidative stress, nitric oxide metabolites, and cortisol levels, unbalanced redox status, transient renal function impairment, and ketosis. A direct correlation between motion sickness symptoms evaluated through questionnaires and NOx levels was also found.

Association of Helicobacter pylori and iNOS production by macrophages and lymphocytes in the gastric mucosa in chronic gastritis

Helicobacter pylori is one of the most common causes of chronic gastritis. With the development of the disease cellular inflammatory infiltrates composed of lymphocytes, plasma cells, and macrophages are formed in epithelium and lamina propria of the stomach. These cells are capable of secreting a number of active substances, including inducible nitric oxide synthase (iNOS). We examined the relationship between H. pylori and secretion of iNOS by cells of inflammatory infiltrates in chronic gastritis by light microscopy and immunohistochemistry. The data obtained indicate that stimulation of H. pylori immune system cells of the host organism during development of chronic gastritis causes increase in number of macrophages and lymphocytes in the inflammatory infiltrate of the gastric mucosa. This is accompanied with increased expression of inducible NO-synthase with excess free radicals in the tissues, which leads to secondary alterations and exacerbates the inflammation with impaired regeneration processes.

Resolution of cyclic vomiting after appendectomy in a girl

Cyclic vomiting syndrome is a disorder characterized by recurrent, discrete, stereotypical episodes of nausea and vomiting. Although chronic or recurrent appendicitis may be a cause of recurrent abdominal pain, it rarely meets the diagnostic criteria for cyclic vomiting syndrome. Furthermore, mast cell counts are histologically high in chronic appendicitis. We report a 10-year-old Japanese girl with a cyclic pattern of vomiting that met the stringent diagnostic criteria for cyclic vomiting syndrome, and which was resolved after appendectomy. Histopathologic examination of the resected appendix showed not only acute mucosal inflammation but also chronic inflammatory changes. Because we speculated that recurrent or chronic appendicitis may have been related to the patient's vomiting bouts, we also immunohistochemically investigated the density of mast cells in the specimen. We found that the mast cell density was markedly high in the lamina propria of the appendix. In our patient, a type I hypersensitivity reaction with release of mediators by mast cells could have been the initial factor triggering the recurrent appendicitis, and this stressor could have initiated the vomiting cascade. In conclusion, chronic or recurrent appendicitis could be one of the causes of cyclic vomiting, and must be considered in the differential diagnosis of cyclic vomiting syndrome.

Erythromycin in therapy of cyclic vomiting syndrome

Cyclic vomiting syndrome is an insufficiently understood disorder which manifests itself in stereotypical episodes of vomiting with no detectable organic cause. Considering its unknown aetiology, drugs borrowed from various medication classes are applied in the therapy of this disorder, with variable success. Among other medicaments, erythromycin is also used in treatment of cyclic vomiting syndrome. This is a case study in which the application of erythromycin led to the prevention of attacks of cyclic vomiting syndrome. Our case report presents how periodical erythromycin therapy in two-week intervals at expected attack periods in a girl led to disappearance of cyclic vomiting. Adverse effects of erythromycin did not show up.

Fasting plasma ghrelin levels in subtypes of anorexia nervosa

Ghrelin has a role in regulating eating behavior and energy metabolism in the central nervous system, and has been reported to play an important role in the pathophysiology of anorexia nervosa (AN). The aim of the present study was to compare fasting plasma ghrelin levels in different subtypes of untreated AN patients. The subjects included 39 female AN patients and 11 female controls. The patients were then divided into two subtypes as follows: 19 AN patients with restricting (AN-R) and 20 AN patients with binge-eating/purging (AN-BP) form of the illness. Blood samples from subjects after an overnight fast were used to analyze plasma ghrelin concentrations. Plasma ghrelin concentrations in both AN-R and AN-BP were negatively correlated with body mass index (BMI). The mean plasma ghrelin levels in both AN-R and AN-BP were significantly higher than that in controls. The mean ghrelin level in AN-BP was significantly higher than that in AN-R. However, mean BMI and serum potassium in both groups were not significantly different. These results suggest that both BMI and the presence of binge-eating/purging may have some influence on fasting plasma ghrelin levels in patients with AN.

Oxidative stress in diabetes-induced endothelial dysfunction involvement of nitric oxide and protein kinase C

Reactive oxygen species (ROS) formation plays a major role in diabetes-induced endothelial dysfunction, though the molecular mechanism(s) involved and the contribution of nitric oxide (NO) are still unclear. This study using bovine retinal endothelial cells was aimed at assessing (i) the role of oxygen-dependent vs. NO-dependent oxidative stress in the endothelial cell permeability alterations induced by the diabetic milieu and (ii) whether protein kinase C (PKC) activation ultimately mediates these changes. Superoxide, lipid peroxide, and PKC activity were higher under high glucose (HG) vs. normal glucose throughout the 30 d period. Nitrite/nitrate and endothelial NO synthase levels increased at 1 d and decreased thereafter. Changes in monolayer permeability to 125I-BSA induced by 1 or 30 d incubation in HG or exposure to advanced glycosylation endproduct were reduced by treatment with antioxidants or PKC inhibitors, whereas NO blockade prevented only the effect of 1 d HG. HG-induced changes were mimicked by a PKC activator, a superoxide generating system, an NO and superoxide donor, or peroxynitrite (attenuated by PKC inhibition), but not a NO donor. The short-term effect of HG depends on a combined oxidative and nitrosative stress with peroxynitrite formation, whereas the long-term effect is related to ROS generation; in both cases, PKC ultimately mediates permeability changes.