Application of a pigment measuring device – Mexameter®– for the differential diagnosis of vitiligo and nevus depigmentosus

Background/purpose: Vitiligo and nevus depigmentosus (ND) present similar hypopigmented macules with significantly different prognoses. Although the distinction between the two diseases is important, differential diagnosis relies on medical history and physical examination, which is far from decisive in some cases. The Mexameter^® is an objective skin color-measuring device, and has been reported to provide a reproducible and sensitive means of quantifying small skin color differences. In this study, we investigated the usefulness of a Mexameter^® for discriminating these diseases.
Methods: A selection of 202 hypopigmented skin lesions (182 from vitiligo and 20 from ND) were the objects of this study. Using a Mexameter, MIs were obtained from lesions and symmetrically located control skin. RMIs, ratios of the MIs of lesional skins to control skins, were calculated.
Results: The mean MIs and RMIs were significantly different for vitiligo and ND. The mean RMI of ND lesions was 74±13, which was significantly higher than that of vitiligo lesions (50±24). No ND lesion had an RMI of <50%.
Conclusion: This study shows that the Mexameter^®, an objective pigment-measuring device, can be used to achieve a more accurate diagnosis of hypopigmentary disorders, and that the relative melanin index (RMI), which represents the relative pigment levels, might be a more effective parameter than the melanin index (MI) itself for comparing pigmentation differences.     

Brain lesions in newborns exposed to high-dose magnesium sulfate during preterm labor.

High-dosage, tocolytic magnesium sulfate (MgSO4) administered to pregnant women during preterm labor can be toxic, and sometimes lethal, for their newborns (Cochrane Database of Systematic Reviews (relative mortality risk 2.82, 95% confidence interval 1.2-6.6)). Based on the results of the Magnesium and Neurologic Endpoints Trial and the work of many others, a unifying triangular concept is proposed to account for the increased prevalence of brain lesions, with their likely resultant mortality, in neonates and infants exposed to high-dose MgSO4 in the context of preterm labor. We review the evidence that: (1) elevated circulating levels of serum ionized magnesium occurring in mothers, and therefore in their babies, at the time of delivery are associated with subsequent neonatal intraventricular hemorrhage (IVH); (2) neonatal IVH is strongly associated with lenticulostriate vasculopathy (LSV), an unusual mineralizing lesion involving the thalami and basal ganglia of the neonate; and, (3) exposure to 50 g or more of tocolytic MgSO4 during preterm labor is associated with the development of LSV.     

Cumulative probability of pregnancy following IVF with ICSI and fresh or frozen embryo transfer.

The authors studied the cumulative probability of pregnancy for up to 4 consecutive embryo transfer (ET) cycles with ICSI performed for male factor. Transfers could be either fresh or frozen. The clinical pregnancy rate (PR) for the first 4 cycles were similar [44% (61/366); 31% (44/138); 45% (14/31); 44% (4/9)]. Delivery rates were also similar. There was a lower PR on the second retrieval vs. the first retrieval (47% vs. 29%), but this may be related to most of the second retrievals occurring in the second transfer cycle (67%, 31/55); this may be explained by women who were poor responders and required another retrieval without a frozen ET. The majority of transfers in cycle 1 were fresh, whereas cycles 2-4 used primarily frozen-thawed embryos. These data should be helpful for patients requiring IVF with ICSI in deciding to continue with more IVF cycles or consider other     

Impaired Lymphocyte Proliferative Response to Mitogen in Alcoholic Patients. Absence of a Relation to Liver Disease Activity

Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease.     

Discrete time optimal control of linear time-delay systems

A discrete time optimal control for linear time-delay systems is developed to ensure that all closed-loop eigenvalues will lie inside a circular region centred at (β;, 0) with radius α. It is shown that by suitable manipulations the problem can be reduced to a standard discrete time quadratic regulator problem. An illustrative example is included to demonstrate the applicability of the proposed method.     

Acute effects of serotonin on rat bladder contractility.

INTRODUCTION: The purpose of this study is to investigate in vitro the effects of serotonin on the rat detrusor. In particular, it examines which drugs inhibit the serotonin-induced detrusor contractions. MATERIALS AND METHODS: Isometric tension changes of isolated rat bladder muscle strips were recorded in an organ bath using a force transducer. Acute effects of serotonin (0.0001-0.01 mM) on resting tension were assessed. Electrical field stimulation (EFS); bethanechol (0.0001-0.01 mM); ATP (1-3 mM)- or KCl (63.5-254 mM)-induced contractions using an application in an organ bath were compared with serotonin-induced contractions. In order to examine the action mechanism of serotonin-induced stimulation, EFS-, bethanechol-, ATP- or KCl-induced contraction on serotonin treatment (0.001 mM) was assessed and serotonin (0.001-0.1 mM) was cumulatively added to the organ bath following preincubation with propranolol, ketanserin, tropisetron, propiverine, sodium nitroprusside or doxazosin. RESULTS: The serotonin-induced response has two phases: an initial transient contraction and a prolonged tonic phase. Serotonin produced a reversible and dose-dependent contraction of the detrusor strips. Responses to bethanechol significantly increased with a concentration of 0.001 mM serotonin (p < 0.05). There was no effect on the responses to ATP, KCl, or EFS on 0.001 mM serotonin. The 5-HT(2) receptor is mainly responsible for serotonin-induced contractions of the detrusor (p < 0.05), while the 5-HT(1) receptor is partially responsible. Doxazosin and propiverine each significantly suppressed the response to serotonin, while sodium nitroprusside and tropisetron each had no effect (p < 0.05). CONCLUSIONS: Because the 5-HT(2) antagonist blocked the effect of serotonin-induced bladder contractions and the stimulation of the adrenoreceptors, the 5-HT(2) antagonist seems to improve lower urinary tract symptoms.     

The in vitro pharmacological profile of KR31080, a nonpeptide AT1 receptor antagonist

Summary— KR31080 (2-butyl-5-methyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b] pyridine) is a potent inhibitor of angiotensin type 1 (AT₁) receptors in rabbit aorta and human recombinant AT₁ receptors. In the isolated rabbit thoracic aorta, KR31080 caused a nonparallel shift to the right of the concentration-response curves to angiotensin II (All) with decreased maximal response (pD'₂ = 10.1 ± 0.1), but had no effect on the contractile response induced by norepinephrine. KR31080 inhibited specific [¹²⁵I]AII binding to rabbit aortic membranes (AT, receptors) and [¹²⁵I][Sar¹, Ile⁸]AII binding to human recombinant AT₁ receptors in a concentration-dependent manner with IC₅₀ values of 0.84 ± 0.08 nM and 1.92 ± 0.15 nM, respectively, but did not inhibit specific [¹²⁵I)AII binding to bovine cerebellum membranes (ÀT₂ receptors). In the Scatchard analysis, KR31080 interacted with rabbit aortic AT₁ receptors in a competitive manner, similar to losartan. These results demonstrate that KR31080 is a potent and AT₁ selective angiotensin receptor antagonist which exerts a competitive antagonism in the [¹²⁵I]AII binding assay and insurmountable AT₁ receptor antagonism in the functional study.