Clinical application of the second morning urine method for estimating salt intake in patients with hypertension

Abstract

Estimation of salt intake by cumbersome 24-h urine collection is not suitable for individual patients because of substantial daily variation in intake. We developed the second morning urine (SMU) method for monitoring daily salt intake in healthy subjects by calculating the daily creatinine excretion and measuring the ratio of sodium to creatinine in the SMU specimen. To determine whether the SMU method was applicable to hypertensive patients, we tested it in hospitalized patients under an equilibrated sodium balance as a model population. This review focuses on application of the SMU method in hypertensive patients with mild target organ damage.     

The use of tetrabutylammonium fluoride to promote N‐ and O‐11C‐methylation reactions with iodo[11C]methane in dimethyl sulfoxide

The N‐ or O‐methylation reactions of compounds bearing amide, aniline, or phenol moieties using iodo[¹¹C]methane (1) with the aid of a base are frequently applied to the preparation of ¹¹C‐labeled radiopharmaceuticals. Although sodium hydride and alkaline metal hydroxides are commonly employed as bases in these reactions, their poor solubility properties in organic solvents and hydrolytic activities have sometimes limited their application and made the associated ¹¹C‐methylation reactions difficult. In contrast to these bases, tetrabutylammonium fluoride (TBAF) is moderately basic, highly soluble in organic solvents, and weakly nucleophilic. Although it was envisaged that TBAF could be used as the preferred base for ¹¹C‐methylation reactions using 1, studies concerning the use of TBAF to promote ¹¹C‐methylation reactions are scarce. Herein, we have evaluated the efficiency of the ¹¹C‐methylation reactions of 13 model compounds using TBAF and 1. In most cases, the N‐¹¹C‐methylations were efficiently promoted by TBAF in dimethyl sulfoxide at ambient temperature, whereas the O‐¹¹C‐methylations required heating in some cases. Comparison studies revealed that the efficiencies of the ¹¹C‐methylation reactions with TBAF were comparable or sometimes greater than those conducted with sodium hydride. Based on these results, TBAF should be considered as the preferred base for ¹¹C‐methylation reactions using 1.     

The platinum (II) complex [Pt(O,O′-acac)(γ-acac)(DMS)] alters the intracellular calcium homeostasis in MCF-7 breast cancer cells

It was previously demonstrated that [Pt(O,O′-acac)(γ-acac)(DMS)] exerted toxic effects at high doses, whilst sub-cytotoxic concentrations induced anoikis and decreased cell migration. Aim of this study was to investigate the hypothesis that [Pt(O,O′-acac)(γ-acac)(DMS)] alters the [Ca²⁺]_i and that this is linked to its ability to trigger rapid apoptosis in MCF-7 cells. Thus, cells were treated with [Pt(O,O′-acac)(γ-acac)(DMS)] and its effects on some of the systems regulating Ca²⁺ homeostasis were studied, also in cells dealing with the complex changes occurring during the Ca²⁺ signalling evoked by extracellular stimuli. [Pt(O,O′-acac)(γ-acac)(DMS)] caused the decrease of PMCA activity (but not SERCA or SPCA) and Ca²⁺ membrane permeability. These two opposite effects on [Ca²⁺]_i resulted in its overall increase from 102 ± 12 nM to 250 ± 24 nM after 15 min incubation. The effects of [Pt(O,O′-acac)(γ-acac)(DMS)] were also evident when cells were stimulated with ATP: the changes in Ca²⁺ levels caused by purinergic stimulation resulted altered due to decreased PMCA activity and to the closure of Ca²⁺ channels opened by purinergic receptor. Conversely, [Pt(O,O′-acac)(γ-acac)(DMS)] did not affect the store-operated Ca²⁺ channels opened by thapsigargin or by ATP. [Pt(O,O′-acac)(γ-acac)(DMS)] provoked the activation of PKC-α and the production of ROS that were responsible for the Ca²⁺ permeability and PMCA activity decrease, respectively. The overall effect of [Pt(O,O′-acac)(γ-acac)(DMS)] is to increase the [Ca²⁺]_i, an effect that is likely to be linked to its ability to trigger rapid apoptosis in MCF-7 cells. These data reinforce the notion that [Pt(O,O′-acac)(γ-acac)(DMS)] would be a promising drug in cancer treatment.     

The effect of sodium hypochlorite and ethylenediaminetetraacetic acid irrigation, individually and in alternation, on tooth surface strain

Aim  To evaluate the effect of irrigation regimens on tooth surface strain using saline, sodium hypochlorite (3% and 5% NaOCl) and ethylenediaminetetraacetic acid (17% EDTA), individually and in alternating combinations.
Methodology  Single-rooted premolar teeth with single canals prepared to standardized dimensions were grouped by anatomical features and randomly distributed amongst six experimental groups ( n  = 12 each). The six groups were: (1) saline; (2) 5% NaOCl; (3) 3% NaOCl; (4) 17% EDTA; (5) 3% NaOCl and 17% EDTA; (6) 5% NaOCl and 17% EDTA. All groups underwent four (group 1) or five (groups 2, 3, 4, 5, 6) sequential 30-min irrigation periods following each of which the tooth was subjected to a standard regime of cyclic, nondestructive, occlusal loading. Tooth surface strain was measured during each loading cycle using electrical strain gauges mounted cervico-proximally. The data were analysed by Hierarchical anova and post hoc multiple comparisons.
Results  Irrigation with 5% NaOCl alone or alternating with 17% EDTA significantly ( P  < 0.001) increased the peak strain values for each of the irrigation periods compared with that of saline (group 1). The data for the other groups revealed no significant differences compared with those of saline. The strain increase after the fourth irrigation cycle was significantly higher for group 6 than for group 2. The measured canal morphology and dentine thickness parameters did not prove to have a significant effect on tooth surface strain.
Conclusions  Irrigation with 5% NaOCl acting alone or alternated with 17% EDTA (used in 30 min cycles), significantly increased tooth surface strain. The alternated regimen showed significantly greater changes in tooth surface strain than NaOCl alone. Irrigation with 3% NaOCl and 17% EDTA individually or in combination did not significantly alter the tooth surface strain.     

Impact of preoperative serum sodium concentration in living donor liver transplantation

Background and Aims: The importance of hyponatremia in deceased donor liver transplantation (DDLT) has been recently discussed frequently. However, its impact on the outcomes in living donor liver transplantation (LDLT) has not yet been elucidated. The current study was designed to demonstrate the impact of pre‐transplant sodium concentration on postoperative clinical outcomes. Methods: One hundred and thirty‐four patients who underwent LDLT for end‐stage liver diseases were examined to evaluate the significance of pre‐transplant hyponatremia (Na ≤ 130 mEq/L) on the short‐term clinical outcomes and the efficacy of the Model for End‐Stage Liver Disease and serum sodium (MELD‐Na) score using the sodium concentration and original MELD score. Results: The preoperative sodium and MELD score for all patients were 133.9 mEq/L (range: 109–142) and 16.2 (range: 6–38), respectively. According to a multivariate analysis, not only the MELD score (P = 0.030) but also the sodium concentration (P = 0.005) were found to be significant predictive factors for short‐term graft survival. Preoperative hyponatremia was a significant risk factor for the occurrence of sepsis (P < 0.001), renal dysfunction (P < 0.001) and encephalopathy (P = 0.026). The MELD‐Na score was 19.6 (range: 6–51) and the area under the receiver–operator curve of that (c‐statistics: 0.867) was higher than MELD score and sodium concentration (c‐statistics: 0.820 and 0.842, respectively). Conclusion: Preoperative hyponatremia was a significant risk for postoperative complications and short‐term graft loss. The addition of sodium concentration to MELD score might therefore be an effective predictor for post‐transplant short‐term mortality in LDLT.     

Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure

Cury JA, do Amaral RC, Tenuta LMA, Del Bel Cury AA, Tabchoury CPM. Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure. Eur J Oral Sci 2010; 118: 370–375. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Because low‐fluoride toothpaste (500 p.p.m. F) has not clearly been shown to be effective for controlling caries in caries‐active children, this experimental in situ study was conducted to evaluate whether its effect, when compared with a conventional toothpaste (1,000–1,500 p.p.m. F), would depend on the cariogenic challenge. During four phases of 14 d each, 14 volunteers used 500 or 1,100 p.p.m. F toothpaste and wore palatal appliances containing deciduous enamel slabs, on which biofilm was accumulated and exposed to 20% sucrose solution at frequencies increasing from two to eight times per day. The F concentration was determined in the biofilm formed, and enamel demineralization was assessed by surface hardness loss (%SHL) and integrated area of hardness × lesion depth (ΔS). The F uptake by enamel was also determined. Fluoride in biofilm fluid and solids was statistically higher when conventional F toothpaste was used. The toothpastes did not differ statistically in terms of %SHL, ΔS, and F in enamel, but only the conventional F toothpaste significantly reduced caries‐lesion progression according to the frequency of sucrose exposure. The findings suggest that the high‐F availability in biofilm, resulting from the use of conventional toothpaste compared with low‐F toothpaste, may be important for reducing caries‐lesion progression in conjunction with a high frequency of sucrose exposure.     

Regulated sodium transport in the renal connecting tubule (CNT) via the epithelial sodium channel (ENaC)

The aldosterone-sensitive distal nephron (ASDN) includes the late distal convoluted tubule 2, the connecting tubule (CNT) and the collecting duct. The appropriate regulation of sodium (Na⁺) absorption in the ASDN is essential to precisely match urinary Na⁺ excretion to dietary Na⁺ intake whilst taking extra-renal Na⁺ losses into account. There is increasing evidence that Na⁺ transport in the CNT is of particular importance for the maintenance of body Na⁺ balance and for the long-term control of extra-cellular fluid volume and arterial blood pressure. Na⁺ transport in the CNT critically depends on the activity and abundance of the amiloride-sensitive epithelial sodium channel (ENaC) in the luminal membrane of the CNT cells. As a rate-limiting step for transepithelial Na⁺ transport, ENaC is the main target of hormones (e.g. aldosterone, angiotensin II, vasopressin and insulin/insulin-like growth factor 1) to adjust transepithelial Na⁺ transport in this tubular segment. In this review, we highlight the structural and functional properties of the CNT that contribute to the high Na⁺ transport capacity of this segment. Moreover, we discuss some aspects of the complex pathways and molecular mechanisms involved in ENaC regulation by hormones, kinases, proteases and associated proteins that control its function. Whilst cultured cells and heterologous expression systems have greatly advanced our knowledge about some of these regulatory mechanisms, future studies will have to determine the relative importance of the various pathways in the native tubule and in particular in the CNT.