Potential interference of in vitro carbamylation on C-reactive protein laboratory measurement.

Carbamylation is a nonenzymatic post-translational modification observed during the reaction between cyanate and amino acids and/or proteins that may occur during some pathologies such as chronic kidney disease. Evidence suggests that carbamylation may interfere with the quantification of some analytes measured using immunoturbidimetric assays. C-reactive protein (CRP) is an inflammatory response protein that is commonly quantified through immunoturbidimetry in clinical laboratories. Because the presence of modified proteins in serum can lead to impaired quantification, this study aimed to verify the impact of in vitro carbamylation on the measurement of CRP in a CRP standard solution and serum pool. The samples were incubated with 150 nM, 150 µM, or 150 mM potassium cyanate (KOCN) or 20, 100, or 500 mg/dL urea at 37 °C for 24 h. CRP concentrations were measured using an immunoturbidimetric assay. The results showed a 61%-72% decrease in the CRP detection rate after incubation with KOCN. Incubation with urea resulted in a 0.7%-8% lower CRP detection rate. The results of this study indicate that high concentrations of cyanate can lead to falsely decreased CRP levels, as measured by immunoturbidimetry.

Anthropometric measurements and their association with endothelial function and arterial stiffness of eutrophic individuals and with overweight

ABSTRACT Objective: The objective of the study was to assess the association of anthropometric measurements with endothelial function and arterial stiffness of eutrophic individuals and with overweight. Subjects and methods: A cross-sectional study was carried out with individuals with body mass index (BMI) between 18.5 kg/m² and < 30 kg/m², low to intermediate global cardiovascular risk scores, and aged ≥ 18 and < 60 years. We assessed the sociodemographic data, anthropometric variables (body weight, height, circumferences of the waist [WC], neck [NC], hip [HC], sagittal abdominal diameter [SAD], [BMI], waist-to-hip ratio [WHR], and waist-to-height ratio [WHtR]), biochemical parameters (lipid profile and nitric oxide), endothelial function (flow-mediated dilation [FMD], by ultrasound), and arterial stiffness (pulse wave velocity [PWV] and the amplification index [AIx@75] by oscillometry). Thirty-six individuals were included, 18 eutrophic and 18 with overweight, with a mean age of 37.5 ± 10.2 years, mostly at low cardiovascular risk (86.1%), female (80.6%), single (52.8%), employed with formal contracts (44.4%), and with over twelve years of education (88.9%). Results: The PWV presented positive and moderate correlation with the WC (r = 0.584; P = 0.001), WHR (r = 0.513; P = 0.001), and WHtR (r = 0.590; P = 0.001), and positive and low correlation with the NC (r = 0.372; P = 0.013) and SAD (r = 0.356; P = 0.033). Moreover, no anthropometric parameter presented a correlation with the AIx@75 or the FMD percentage in the total sample. Conclusion: Our findings show that in eutrophic individuals and with overweight the WC, WHR, WHtR, SAD, and NC were positively correlated with the PWV but not to the endothelial function in the overall sample. These are hypothesis-generating findings and they should be replicated in other studies.

Vaginal delivery is associated with lower levels of thiol groups, vitamin C and ferric reducing ability in colostrum compared with caesarean section.

This study aimed to investigate the effects of delivery type (normal or caesarean) on the antioxidant and oxidative capacity of colostrum collected shortly after delivery. A total of 61 parturients were included in the study and divided into two groups: those who underwent vaginal delivery (n = 36) and those who underwent elective caesarean section (n = 25). Colostrum samples were collected by manual milking up to 48 h post parturition and analysed for thiol groups (-SH), vitamin C, ferric reducing ability (FRAP), nitrate/nitrite oxides (NOx), and advanced oxidation protein products (AOPP). Colostrum levels of -SH (p = 0.0042), vitamin C (p = 0.0455), and FRAP (p = 0.0374) were significantly lower in the vaginal delivery group. The results suggest that vaginal delivery, compared to caesarean section, is associated with lower levels of antioxidants in colostrum and the mode of delivery plays an important role in the composition of antioxidants in maternal colostrum that help protect newborns from oxidative damage.IMPACT STATEMENTWhat is already known on this subject? Colostrum is the first biological fluid produced by the mother after delivery and is responsible for a child's growth, cognitive development and health. It is known that childbirth can cause oxidative imbalance, and its effects have already been evaluated in maternal and foetal blood, however, there are few studies evaluating the effects of childbirth on colostrum composition.What do the results of this study add? Previously, a study showed that caesarean section caused greater oxidation of colostrum compared to vaginal delivery. Thus, we sought to evaluate other markers (thiol groups, vitamin C, ferric reducing ability, nitrate/nitrite oxides, and advanced oxidation protein products), in a short period of time after delivery, in order to elucidate this still little discussed issue. Unlike the previous one, our study suggests that vaginal delivery, compared to caesarean section, is associated with lower levels of antioxidants in colostrum, which may make it difficult to protect newborns from oxidative damage.What are the implications of these findings for clinical practice and/or further research? Our study suggests that normal delivery can influence the antioxidant composition of maternal colostrum, and it is debateable for future clinical practice to improve eating habits during pregnancy and lactation, in order to strengthen the antioxidant capacity of colostrum and reduce oxidative damage to newborns.

Acute effect of coffee on arterial stiffness and endothelial function in overweight and obese individuals: A randomized clinical trial.

INTRODUCTION: Coffee is one of the most consumed foodstuffs worldwide. Studies of coffee intake in healthy subjects have shown controversial effects on vascular function. However, little is known of coffee intake effects on the endothelium of overweight and obese individuals. OBJECTIVE: To investigate the acute effects of caffeinated and decaffeinated coffee intake on the endothelial function and arterial stiffness in overweight and obese individuals. METHODS: A randomized, double-blind, crossover clinical trial was designed to investigate the effects of regular caffeinated coffee and decaffeinated coffee on the endothelium. Each subject had both caffeinated coffee and decaffeinated coffee, separated by a washout period of seven days. The endothelial function was measured by flow-mediated dilation (FMD) assessed by ultrasound. Arterial stiffness was measured by an automatic oscillometric device. Blood samples were collected to assess the lipid and nitric oxide profiles. RESULTS: There were 18 subjects included in the study, aged 37.4 ± 10.0 years, with an average BMI of 28.96 ± 2.42, with the majority being female (61.1%). The caffeinated coffee increased central systolic blood pressure (P < 0.001), central diastolic blood pressure (P < 0.001) and pulse wave velocity (P < 0.001), but the decaffeinated coffee did not affect these variables. However, there was a better effect on FMD in the caffeinated coffee intake group (P = 0.014). CONCLUSION: In overweight and obese individuals, caffeinated coffee increased central blood pressure and pulse wave velocity but not the decaffeinated coffee. While caffeinated coffee showed an improvement on hyperemia-induced endothelial function. REGISTRATION NUMBER OF CLINICAL TRIAL: Platform of the Brazilian Registry of Clinical Trials under number RBR-65cxtr.

Activity of the enzyme delta-aminolevulinate dehydratase and parameters of oxidative stress in different modes of delivery.

AIMS: The objective of this study was to investigate the effect of the type of delivery (vaginal and cesarean) on the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D), which as yet has not been studied, and the markers of oxidative stress. METHODS: Seventy-six mothers and their newborns were divided into two groups: normal birth (VD) and elective cesarean section (ECS). Samples of maternal and umbilical cord blood were collected up to 5 min after birth. Thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), protein thiol (P-SH), nonprotein (NP-SH), the ferric reducing ability of plasma (FRAP), total antioxidant capacity (TAC), catalase, and δ-ALA-D enzyme activity were tested. RESULTS: TBARS and AOPP were significantly higher in mothers of the VD group, while P-SH, NP-SH, FRAP and TAC were reduced. In newborns, TBARS and AOPP did not differ between the groups; however, in the VD group, there was a decrease in P-SH, NP-SH, FRAP, TAC, and catalase. The activity of the δ-ALA-D enzyme was decreased in mothers and neonates born by VD. CONCLUSIONS: Mothers undergoing VD had higher levels of free radicals and lower antioxidant defenses, while their newborns decreased antioxidant defenses likely to contain the oxidative imbalance. The inhibition of the δ-ALA-D enzyme in this scenario allows its use as a useful marker of oxidative stress in different obstetric settings.

Characterisation of nociception and inflammation observed in a traumatic muscle injury model in rats.

Muscle pain is the most prevalent type of pain in the world, but treatment remains ineffective. Thus, it is relevant to develop trustable animal models to understand the involved pain mechanisms. Therefore, this study characterised the nociception and inflammation in a traumatic muscle injury model in rats. A single blunt trauma impact on the right gastrocnemius muscle of male Wistar rats (250-350 g) was used as model for muscle pain. Animals were divided into four groups (sham/no treatment; sham/diclofenac 1%; injury/no treatment; injury/diclofenac 1%) and the topical treatment with a cream containing 1% monosodium diclofenac (applied at 2, 6, 12, 24, and 46 h after muscle injury; 200 mg/muscle) was used as an anti-inflammatory control. Nociception (mechanical and cold allodynia, or nociceptive score) and locomotor activity were evaluated at 26 and 48 h after injury. Also, inflammatory and oxidative parameters were evaluated in gastrocnemius muscle and the creatine kinase (CK) activity and lactate/glicose levels in rat's serum and plasma, respectively. Muscle injury caused mechanical and cold allodynia, and increased nociceptive scores, without inducing locomotor impairment. This model also increased the inflammatory cells infiltration (seen by myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities and histological procedure), nitric oxide, interleukin (IL)-1ß, IL-6, and dichlorofluorescein fluorescence in muscle samples; and CK activity and lactate/glicose ratio. The treatment with 1% monosodium diclofenac reduced inflammatory cells infiltration, dichlorofluorescein fluorescence and lactate/glicose levels. Thus, we characterised the traumatic muscle injury as a reproducible model of muscle pain, which makes it possible to evaluate promising antinociceptive and anti-inflammatory therapies.

Influence of maternal labor time on delta-aminolevulinate dehydratase enzyme activity and markers of oxidative stress in newborns.

The purpose is to determine markers of oxidative stress related to the longer and shorter duration of labor (DOL) of pregnant women in the umbilical cord blood of neonates, not yet studied. Blood samples from the umbilical cord were collected from pregnant women with normal delivery and classified according to DOL in two groups: a group with DOL less than 310 min (n = 33) and a group with DOL greater than or equal to 310 min (n = 35). The oxidative stress parameters were analyzed by the quantification of thiobarbituric acid reactive substances (TBARS), nitrate/nitrite (NOx), protein thiol groups (P-SH) and non-protein (NP-SH), vitamin C and plasma iron reduction capacity (FRAP), in addition to the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D). The activity of the δ-ALA-D enzyme was shown to be decreased in longer DOL, however, the oxidant parameters and antioxidants were higher in the longer DOL, with the exception of NP-SH that was lower. The longer maternal DOL time is related to the alteration of δ-ALA-D enzyme activity and other parameters in neonates, suggesting an increase in the passage of maternal oxidative markers by umbilical cord blood.

Longitudinal Study of Delta-Aminolevulinate Dehydratase Activity and Oxidative Profile in Healthy Pregnant Women.

Pregnancy is characterized by changes in various organs, triggering changes in the use of energy substrates and increased oxygen consumption. In addition, gestation is an oxidative event that can be assessed by the relationship between free radicals and antioxidants produced by the body. Excessive production of free radicals has detrimental effects such as damage to enzymes, carbohydrates, and DNA. Thus, the objective of this study was to evaluate the oxidative status and antioxidant responses throughout pregnancy through a longitudinal study. Reactive oxygen species were analyzed by means of thiobarbituric acid reactive substances and nitric oxide, the antioxidant system through vitamin C, sulfhydryl groups, total antioxidant capacity, and ferric reducing ability of plasma as well as enzymes such as catalase and delta-aminolevulinate-dehydratase in pregnant women in the three gestational trimesters (n = 30). According to the results, the markers of oxidative damage showed significant differences in the different gestational trimesters where they were increased in the second trimester when compared to the first trimester. The antioxidant defenses responded differently in each gestational trimester, suggesting a response pattern to try to combat the damage caused by free radicals, in order to stabilize the increase of oxidative stress caused in the second gestational trimester.