Magnesium supplementation helps to improve carotid intima media thickness in patients on hemodialysis

Background  The atherosclerotic process progresses more dynamically in hemodialysis (HD) patients than in the general population. In HD patients, lower magnesium levels were reported to be associated with increased atherosclerosis of the common carotid artery. We tested the hypotheses that magnesium supplementation helps to improve carotid intima media thickness (IMT) in HD patients. Materials and methods  A total of 47 patients on HD were included in the study. Patients were randomly divided into two groups: group A (Mg group), in which patients were given magnesium citrate orally at a dosage of 610 mg every other day for 2 months and group B (control group), in which patients received only calcium acetate therapy as a phosphate binder. At baseline and 2 months later, all patients underwent a carotid artery ultrasound scan to measure carotid IMT. Results  At the end of 2 months, mean serum calcium, phosphorus, and calcium × phosphorus product were not changed in both groups. As expected, mean serum Mg level significantly increased in the Mg group at the end of 2 months. In addition, serum parathyroid hormone (PTH) level significantly decreased in the Mg group at the end of 2 months (P = 0.003). Baseline carotid IMT was similar between the groups. Bilateral carotid IMT was significantly improved in patients treated with magnesium citrate compared to initial values (P = 0.001 for left, P = 0.002 for right). Conclusion  Based on the present data, magnesium may play an important protective role in the progression of atherosclerosis in patients on dialysis. Further studies are needed to assess more accurately the role of magnesium in atherosclerotic regression in dialysis patients.     

Nitric Oxide and Antioxidant Defense in Patients with Gastric Cancer

In the present study, total nitrate and nitrite level (as end product of nitric oxide), superoxide dismutase activity, and glutathione peroxidase activity in leukocytes were determined in patients with gastric cancer, and the relationship between measured parameters and tumor grade were evaluated. Leukocyte nitrate and nitrite level was found to be increased and superoxide dismutase activity was found to be decreased in patients compared to controls. When the patient group was categorized, nitrate and nitrite level was found to be higher in patients with a high-grade tumor than in patients with a grade I tumor. We concluded that an increased level of leukocyte nitrate and nitrite is related to tumor grade in patients with gastric cancer; antioxidant activity is also impaired in these patients but it does not seem to be related to grade of tumor.     

Boosted tuberculin skin testing in hemodialysis patients

BACKGROUND: Tuberculosis remains a significant health problem for patients receiving long-term hemodialysis (HD). The tuberculin skin test (TST) is an important method of detecting Mycobacterium tuberculosis infection. Cutaneous anergy decreases the accuracy of the test in these patients. Higher and repeating doses have been mentioned in the immunosuppressed patients. This study examined the significance and frequency of the booster phenomenon in 2-step tuberculin testing of these patients. METHODS: A total of 106 outpatients in a hospital-based HD center in Turkey were screened with 5 and 10 tuberculin units (TU) and Candida antigen. To determine the frequency of booster phenomenon, patients with <10 mm indurations to the initial TST with 5 TU were given a second test with 10 TU, 7 days later. RESULTS: Forty (37.7%) of 106 patients had a significant tuberculin reaction (>or=10 mm) on the initial TST with 5 TU. The booster effect was detected in 16 (24.3%) of 66 patients who had a negative reaction (相似文献   

Is Hepatitis C Virus Positivity a Contributing Factor to Occult Hepatitis B Virus Infection in Hemodialysis Patients?

Hepatitis B (HBV) infections continue to occur in adult hemodialysis units. Occult HBV infection (serum hepatitis B surface antigen [HBsAg] negative but HBV DNA positive) may be a contributing factor in these patients. This study was designed to (1) investigate the prevalence of occult HBV infection in hemodialysis patients and (2) compare the prevalence of occult HBV infection among hepatitis C (HCV)-positive and HCV-negative hemodialysis patients. The study included 138 patients on chronic hemodialysis. Eighty-four patients were HCV positive and 54 were HCV negative. HBV DNA testing was performed by polymerase chain reaction. We also recorded general characteristics of the patients, duration of hemodialysis, and serum alanine aminotransferase and aspartate aminotransferase levels. Twenty-one (15.2%) of the 138 hemodialysis patients were HBV DNA positive. Nine (16.6%) of the 54 anti-HCV antibody negative hemodialysis patients were HBV DNA positive. Twelve (14.2%) of the 84 anti-HCV antibody positive patients were HBV DNA positive. The prevalence in anti-HCV Ab positive and negative hemodialysis patients were same (P > .05). Hemodialysis duration, demographic features, and biochemical parameters were not significantly different in patients with and without occult HBV infection in both HCV-positive and -negative hemodialysis patients (P > .05). HCV positivity is not a contributing factor to occult HBV infection in hemodialysis patients. None of the parameters tested help to distinguish patients with occult HBV infection from those who are HBV DNA negative.     

COMT genotype predicts BOLD signal and noise characteristics in prefrontal circuits

OBJECTIVE: Prefrontal dopamine (DA) is catabolized by the COMT (catechol-O-methyltransferase) enzyme. Literature suggests that the Val/Met single nucleotide polymorphism (SNP) in the COMT gene predicts executive cognition in humans with Val carriers showing poorer performance due to less available synaptic DA. Recent fMRI studies are thought to agree with these studies having demonstrated prefrontal hyperactivation during n-back and attention-requiring tasks. This was interpreted as "less efficient" processing due to impaired signal-to-noise ratio (SNR) of neuronal activity. However, electrophysiological studies of neuronal SNR in primates and humans imply that prefrontal cortex should show a diminished prefrontal BOLD response in Val carriers. In the present study, we addressed the question of whether the prefrontal SNR of the BOLD response is decreased in Val carriers using a visual oddball task and an approach to analysis of fMRI data that maximizes noise characterization. METHODS: We investigated N=17 homozygous Met carriers compared with N=24 Val carriers matched for age, sex, education, IQ, reaction time (variability) and head motion. Event-related fMRI was conducted presenting 160 visual stimuli (40 targets, checkerboard reversal). Subjects had to respond as quickly as possible to targets by button press. In the fMRI GLM [y(t)=beta*x(t)+c+e(t)] analysis, voxel-by-voxel 'activation' [y(t)] as well as residual noise variance [e(t)=sigma2] were calculated using a conservative full-width half maximum (FWHM=6 mm). RESULTS: As compared to Val carriers, we observed a stronger and more extended BOLD responses in homozygous Met carriers in left supplementary motor area (SMA) extending to ACC and dorsolateral prefrontal cortex. Vice versa, increased levels of noise were seen in Val carriers surrounding the peak activation maximum. DISCUSSION: In line with our expectations from prior electrophysiological studies, we observed a diminished BOLD response and increased noise in Val carriers. This suggests that the DA stabilizes cortical microcircuits by sharpening the signal and suppressing surrounding noise.     

Frequency of allergic diseases following measles

ObjectiveViral and bacterial infections in childhood decrease the likelihood of allergic diseases in later life. The frequency of allergic diseases in patients with a histor of measles has been reported to be low but some studies still suggest that measles can increase the frequency of allergic diseases. The aim of this study was to investigate the frequency of allergic diseases following measles in childhood.MethodsFifty-two children hospitalized in our clinic with measles were compared with 51 children without measles. Allergic diseases were investigated in both groups by using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. In all children, allergy skin tests were performed with the four most common allergens.ResultsSensitivity to Dermatophagoides pteronyssinus was less frequent in children with measles than in those without (p < 0.05). A history of nebulized salbutamol use in the emergency room in the previous 12 months was also less frequent in the measles group (p < 0.05). Inhaled corticosteroid use was more common in the group without measles (p < 0.05).ConclusionThe results of this study indicate that findings of allergic disease are less frequent in children with a history of measles. These children were less sensitive to D. pteronyssinus.     

Leukocyte DNA damage in children with iron deficiency anemia: effect of iron supplementation

Iron deficiency is frequently associated with anemia. Iron is a transition-metal ion, and it can induce free radical formation, which leads to formation of various lesions in DNA, proteins, and lipids. The aim of this study was to investigate baseline oxidative DNA damage and to clarify the role of the administration of a therapeutic dose of iron on DNA oxidation in children with iron deficiency anemia (IDA). Twenty-seven children with IDA and 20 healthy children were enrolled in the study. Leukocyte DNA damage (strand breaks and Fpg-sensitive sites) was assessed using comet assay before and after 12 weeks of daily iron administration. Before the iron administration, the frequency of DNA strand breaks in the children with IDA was found to be lower than those in the control group (P < 0.05), but there was not a significant difference for frequency of Fpg-sensitive sites. After 12 weeks of iron administration, the frequency of both DNA strand breaks and Fpg-sensitive sites were found to be increased (P < 0.01). No significant association was determined between DNA damage parameters and hemoglobin, hematocrit, serum iron, total iron binding capacity, and ferritin. In conclusion, basal level of DNA strand breaks is at a low level in children with IDA. After iron administration, DNA strand breaks and Fpg-sensitive sites, which represent oxidatively damaged DNA, increased. However, this increase was unrelated to serum level of iron and ferritin.     

Accuracy and reliability of PBV ASPECTS,CBV ASPECTS and NCCT ASPECTS in acute ischaemic stroke: a matched-pair analysis

Background and purposeTo investigate the reliability and accuracy of Alberta Stroke Program Early Computed Tomography Scores (ASPECTS) derived from flatpanel detector computed tomography pooled blood volume maps compared to non-contrast computed tomography and multidetector computed tomography perfusion cerebral blood volume maps.MethodsASPECTS from pooled blood volume maps were evaluated retrospectively by two experienced readers for 37 consecutive patients with acute middle cerebral artery (MCA) M1 occlusion who underwent flatpanel detector computed tomography perfusion imaging before mechanical thrombectomy between November 2016 and February 2019. For comparison with ASPECTS from non-contrast computed tomography and cerebral blood volume maps, a matched-pair analysis according to pre-stroke modified Rankin scale, age, stroke severity, site of occlusion, time from stroke onset to imaging and final modified thrombolysis in cerebral infarction (mTICI) was performed in a separate group of patients who underwent multimodal computed tomography prior to mechanical thrombectomy between June 2015 and February 2019. Follow-up ASPECTS were derived from either non-contrast computed tomography or from magnetic resonance imaging (in seven patients) one day after mechanical thrombectomy.ResultsInterrater agreement was best for non-contrast computed tomography ASPECTS (w-kappa = 0.74, vs. w-kappa = 0.63 for cerebral blood volume ASPECTS and w-kappa = 0.53 for pooled blood volume ASPECTS). Also, accuracy, defined as correlation between acute and follow-up ASPECTS, was best for non-contrast computed tomography ASPECTS (Spearman ρ = 0.86 (0.65–0.97), P < 0.001), while it was lower and comparable for pooled blood volume ASPECTS (ρ = 0.58 (0.32–0.79), P < 0.001) and cerebral blood volume ASPECTS (ρ = 0.52 (0.17–0.80), P = 0.001). It was noteworthy that cases of relevant infarct overestimation by two or more ASPECTS regions (compared to follow-up imaging) were observed for both acute pooled blood volume and cerebral blood volume ASPECTS but occurred more often for acute pooled blood volume ASPECTS (25% vs. 5%, P = 0.02).ConclusionNon-contrast computed tomography ASPECTS outperformed both pooled blood volume ASPECTS and cerebral blood volume ASPECTS in accuracy and reliability. Importantly, relevant infarct overestimation was observed more often in pooled blood volume ASPECTS than cerebral blood volume ASPECTS, limiting its present clinical applicability for acute stroke imaging.