Does hepatic metabolism of melatonin affect the endogenous serum melatonin level in man?

Melatonin (MT) is metabolized in the liver by cytochrome P450 (CYP) 1A2 but its importance for the metabolic process has not been fully elucidated. Therefore, the objective of this investigation was to study whether patients with different CYP1A2 activity would have different nocturnal serum MT levels. For that purpose serum MT concentrations were determined every second hour during the night in 12 healthy subjects and their MT areas under the curve (MT-AUCs) were calculated. Caffeine (CA) clearance was determined in advance. It is generally accepted that CA clearance reflects CYP1A2 activity. This made it possible to evaluate whether a relationship prevails between endogenous MT-AUCs and CYP1A2 activity. If CYP1A2 is of importance for the metabolism of MT one would expect to find an inverse correlation between the MT-AUCs and the CA clearance. However, such correlation did not exist in the current study (Rs=-0.021, NS). Since endogenous MT-AUC is dependent not only on MT elimination by CYP1A2 but also on MT secretion, it is possible that an increased MT secretion counter-balances an increased hepatic MT metabolism. If so, this could explain why the MT-AUCs and the CA clearance values were not inversely correlated in this study.     

Does claudication affect the development of coronary collaterals?

Atherothrombosis is a generalized disease process that affects large- and medium-diameter arteries throughout the arterial tree. In this study, we aimed to evaluate the correlation between collaterals in different vascular beds. Patients who had undergone digital subtraction angiography for symptomatic lower extremity peripheral arterial disease and coronary angiography after an acute anterior myocardial infarction (MI) were compared with a control group composed of those patients who were hospitalized for acute anterior MI and underwent coronary angiography but had no claudication and had an ankle-brachial index of greater than 0.9 in both legs. In claudicants, stenosis in the left anterior descending artery (LAD) (90.3 ± 17.5 vs 78.6 ± 13.8, P = 0.005) was greater compared with the patients without claudication. The collaterals to the LAD (88% vs 37.5%, P = 0.001) and the collateral grades (1.7 ± 0.7 vs 0.7 ± 0.9, P = 0.001) were higher in the patients with claudication compared with those without claudication. A previous history of angina (52.2% vs 16.3%, P = 0.001), claudication (39.1% vs 4.6%, P = 0.001), and peripheral collaterals (45.7% vs 6.9%, P = 0.001) were higher in the patients with coronary collaterals than in those without. The factors affecting the development of coronary collaterals were claudication [relative risk (RR): 8.8; 95% confidence interval (CI): 2.1–39.8], peripheral collaterals (RR: 1.1; 95% CI: 1.1–1.3), and LAD stenosis (RR: 1.2; 95% CI: 0.03–29.1). Our results suggest that the presence of collateralization or angiogenesis in one vascular bed highly predicts collateralization in another arterial bed.     

Does atopy affect the course of viral pneumonia?

Background

The presence of atopy is considered as a risk factor for severe respiratory symptoms in children. The objective of this study was to examine the effect of atopy on the course of disease in children hospitalised with viral pneumonia.

Does aging affect the use of shifting standards?

Prior research on the use of stereotypes in social judgments has shown that whether young adults make stereotype-consistent or -inconsistent judgments depends in part upon the response scale that is used. This shifting standards effect in stereotype use was examined in the present study to determine whether older adults, who tend to rely on stereotypes more than younger adults, would also show a similar effect. Young and older adults evaluated the height of male and female targets using either an objective or subjective scale. No age differences were found, with both age groups producing stereotype-consistent judgments (i.e., men are taller than women) on an objective scale, but stereotype-inconsistent judgments (i.e., men and women are equally tall) on a subjective scale. These results suggest that the shifting standards effect holds across the adult life span.     

Does Helicobacter pylori gastritis affect motor function of proximal stomach in dyspeptic patients?

The role of Helicobacter pylori infection in proximal gastric motor function and its relation to symptoms in patients with functional dyspepsia is still unclear. We prospectively studied 26 patients with dyspepsia, no structural abnormalities found during endoscopy and biopsy-proven Helicobacter pylori-positive gastritis before and three months after Helicobacter pylori treatment. We used an 11-item score list to evaluate symptoms, gastric biopsies for histology, and a gastric barostat (isobaric inflation–deflation) for proximal gastric motility. Minimal distending pressure (MDP), mean gastric volume at operating pressure, AUC of inflation–deflation cycles, and hysteresis (difference in AUC during inflation and AUC during deflation) were calculated. After three months, Helicobacter pylori was eradicated in 96% of patients. MDP, mean gastric volume at operating pressure, gastric compliance, and hysteresis did not change significantly. Aggregate symptom score as well as histology scores in antrum and corpus decreased significantly. Reduction in postprandial pain correlated with a change in hysteresis (r = 0.567, P < 0.01), but other symptoms did not. Reduction of corpus inflammatory activity correlated with changes in hysteresis (r = 0.604, p < 0.005), suggesting that the stomach attains it original shape faster when inflammation is reduced. These observations suggest that inflammatory changes or release of inflammatory substances associated with Helicobacter pylori infection may influence proximal gastric motor characteristics.     

Cancer and resuscitation. Does the diagnosis affect the decision?

We asked if physicians are less likely to resuscitate patients with cancer because of the diagnostic label alone. We composed a questionnaire of nine patient vignettes with similar expected mortality rates, identical quality of life, and witnessed cardiopulmonary arrest. Internists and neurologists in a university training program were asked to decide, for each "patient," whether to administer cardiopulmonary resuscitation (CPR) before and after being informed of similar mortality rates. Decisions for CPR were less frequent for cancer vignettes than for vignettes of other chronic medical illnesses before and after mortality information was given. Analysis indicated that decisions varied among physicians according to their subspecialties. Overall, women favored resuscitation less often than did men. The diagnosis of cancer appears to have a negative impact on physicians' CPR decisions over and above that due to inaccurate prognostic assumptions about cancer. A physician's subspecialty and gender may also influence resuscitation decisions for patients in general.     

Does prematurity affect thrombocytopoiesis?

Data concerning thrombocytopoiesis in newborns are poorly recognized. Platelets have a crucial role in hemostatic physiology, which is deficient in newborns, especially in preterm newborns. A total of 51 preterm newborns (PTN), 25 girls and 26 boys, were recruited for the study. The control group consisted of 25 female and 30 male healthy term newborns (HTN). Plasma thrombopoietin (TPO) was measured using Quantikine human TPO system. Reticulated platelets (PLRET) was estimated by means of Retic-Count Kit. Platelet count (PLT) was determined using Advia^TU 120 Hematology System. TPO was evidently higher in PTN (110.9?pg/ml) than in HTN (71.5?pg/ml), (p?<?0.001). The percentage of reticulated platelets (PLRET) was also twice as high in PTN (3.49%) in comparison to HTN (1.7%), (p?<?0.001). The PLT count was lower in PTN (246.7?×?10³?µL) than in HTN (287.2?×?10³?µL), (p?<?0.01). Increased TPO levels and the percentage of PLRET indicate that thrombocytopoiesis is more active in prematurity. Our finding may be useful in therapeutic strategies.     

Does prematurity affect thrombocytopoiesis?

Data concerning thrombocytopoiesis in newborns are poorly recognized. Platelets have a crucial role in hemostatic physiology, which is deficient in newborns, especially in preterm newborns. A total of 51 preterm newborns (PTN), 25 girls and 26 boys, were recruited for the study. The control group consisted of 25 female and 30 male healthy term newborns (HTN). Plasma thrombopoietin (TPO) was measured using Quantikine human TPO system. Reticulated platelets (PLRET) was estimated by means of Retic-Count Kit. Platelet count (PLT) was determined using Advia(TU) 120 Hematology System. TPO was evidently higher in PTN (110.9 pg/ml) than in HTN (71.5 pg/ml), (p < 0.001). The percentage of reticulated platelets (PLRET) was also twice as high in PTN (3.49%) in comparison to HTN (1.7%), (p < 0.001). The PLT count was lower in PTN (246.7 x 10(3) microL) than in HTN (287.2 x 10(3) microL), (p < 0.01). Increased TPO levels and the percentage of PLRET indicate that thrombocytopoiesis is more active in prematurity. Our finding may be useful in therapeutic strategies.     

Does Helicobacter pylori affect gastric mucin expression? Relationship between gastric antral mucin expression and H. pylori colonization

BACKGROUND/OBJECTIVE: Helicobacter pylori colonizes the gastric mucous gel layer, the surface epithelium and glands. It has been shown that H. pylori infection causes aberrant expression of gastric mucins MUC 5 and MUC 6. This study aimed to determine the distribution of MUC 5 and MUC 6 in the gastric antrum of dyspeptic patients, and to investigate changes in this pattern in the presence of H. pylori and after successful eradication. MATERIALS AND METHODS: Gastric antrum biopsy specimens were examined by immunohistochemistry for mucin gene (MUC 5 and MUC 6) expression. Polyclonal antibodies were used to detect amino acid tandem repeats of each protein. A scoring system (0-3) was used to assess staining intensity at three sites: foveola, mucous neck cells and glands. H. pylori status was determined by histology and rapid urease test, and considered positive or negative when both tests were positive or negative, respectively. The study included 49 patients positive for H. pylori, in 36 of whom successful eradication was performed, and 11 H. pylori-negative patients. RESULTS: There was a gradient of MUC 5 expression, higher to lower, from the surface to the glands, which was more pronounced before eradication. Increased MUC 5 synthesis in the mucous neck cells and in the glands was found after H. pylori eradication (P = 0.016). MUC 6 was synthesized in the glands more than in the mucous neck cells or foveola. MUC 6 was also secreted into the lumen and probably comprised the superficial part of the unstirred mucous layer. CONCLUSION: The change in MUC 5 synthesis may reflect H. pylori colonization.     

High titer of serum antiphospholipid antibody levels in adult Henoch-Schönlein purpura and cutaneous leukocytoclastic angiitis

OBJECTIVE: To investigate a possible role of antiphospholipid (aPL) antibodies in adult Henoch-Sch?nlein purpura (HSP) and cutaneous leukocytoclastic angiitis (CLA). METHODS: We reviewed the records of 30 HSP and 8 CLA adults with an initial cutaneous manifestation of palpable purpura on their lower extremities between 2003 and 2007. Eight microscopic polyangiitis (MPA) patients and 30 healthy persons were recruited as controls. Serum anticardiolipin (aCL), anti-phosphatidylserine-prothrombin complex (anti-PS/PT), and anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibody levels in HSP, CLA, MPA patients, and healthy controls were measured by enzyme-linked immunosorbent assay. RESULTS: Twenty-two HSP patients (73%) were positive for serum IgA aCL antibodies. Nineteen (63%) had IgA anti-PS/PT antibodies and 4 (13%) had IgA anti-beta(2)GPI antibodies. IgA aCL and anti-PS/PT antibodies showed a significant correlation (P = 0.007). Twenty (67%) HSP patients had IgM anti-PS/PT antibodies and 6 (20%) had IgG anti-PS/PT antibodies. Six (75%) CLA patients had IgM anti-PS/PT antibodies and 2 (25%) had IgG anti-PS/PT antibodies. In contrast, aPL antibodies were not found in any MPA patients or normal controls. Serum IgA aCL antibody levels in HSP patients showed a significant correlation with serum IgA and C-reactive protein (CRP) levels (P = 0.030 and 0.039, respectively). A positive correlation between CRP and serum IgA anti-PS/PT antibody levels was observed in HSP patients (P = 0.023). Serum IgA aCL antibody levels were also significantly associated with proteinuria according to urinalysis (P = 0.024). CONCLUSION: Serum levels of IgA aCL and anti-PS/PT antibodies were elevated in adult HSP, suggesting that serum IgA antibodies may play some role in adult HSP. IgA aCL and/or anti-PS/PT antibodies could serve as markers for adult HSP and should be monitored as an indicator of adult HSP activity. Small-vessel vasculitis could be dependently associated with the presence of IgM anti-PS/PT antibodies. These findings suggest that aPL antibodies are closely related to the pathogenic factors that trigger the development of vasculitis.