A stepwise protocol to coat aAPC beads prevents out-competition of anti-CD3 mAb and consequent experimental artefacts.

Artificial antigen-presenting cells (aAPC) are widely used for both clinical and basic research applications, as cell-based or bead-based scaffolds, combining immune synapse components of interest. Adequate and controlled preparation of aAPCs is crucial for subsequent immunoassays. We reveal that certain proteins such as activatory anti-CD3 antibody can be out-competed by other proteins (e.g. inhibitory receptor ligands such as PDL1:Fc) during the coating of aAPC beads, under the usually performed coating procedures. This may be misleading, as we found that decreased CD8 T cell activity was not due to inhibitory receptor triggering but rather because of unexpectedly low anti-CD3 antibody density on the beads upon co-incubation with inhibitory receptor ligands. We propose an optimized protocol, and emphasize the need to quality-control the coating of proteins on aAPC beads prior to their use in immunoassays.

Prevalences of masked and white-coat hypertension in the Lausanne population: the Hercules Study

Background and Objectives: Few population-based data on the prevalences of masked and white-coat hypertension exist. We collected 24-hour ambulatory blood pressure (BP) and urine in a random subset of participants to the population-based CoLaus study. Methods: Clinic BP was measured using an Omron HEM 907 device and ambulatory BP (ABP) using a Diasys Integra device. Masked hypertension (MH) was defined as clinic BP < 140/90mm Hg and 24-hour ABP >¼135/85mmHg. White coat hypertension (WCH) was defined as clinic BP >¼ 140/90mm Hg and ABP <135/85mm Hg. Microalbuminuria was defined as present if urinary albumin excretion was > 20mg/min. Results: The 198 men and 213 women were aged (mean_SD) 56.2_10.7 and 57.2_10.3 years and had mean urinary excretion of 148_65 and 122_52 mmol/24 h for sodium and 70_24 and 5721 mmol/24 h for potassium, respectively. In men and women, the prevalences were 34.9% and 31.0% for clinic hypertension, 42.9% and 32.9% for ambulatory hypertension, 12.6% and 5.6% for MH, and 4.5% and 3.8% for WCH, respectively. The higher prevalence of MH in men was explained, in part, by higher alcohol consumption and smoking. Participants with MH tended to have higher microalbuminuria (13.5% vs 5.8%, P¼0.067). Participants with WCH had no microalbuminuria. Conclusions: In the Lausanne population aged 38 to 78 years, the prevalence of hypertension based on ABP was high, despite moderate dietary salt intake. Men had higher prevalence of MH then women. The prevalence of WCH was low and similar in men and women. MH tended to be associated with early kidney damage.

Coat color dilution in mice because of inactivation of the melanoma antigen MART-1.

Melanoma antigen recognized by T cells 1 (MART-1) is a melanoma-specific antigen, which has been thoroughly studied in the context of immunotherapy against malignant melanoma and which is found only in the pigment cell lineage. However, its exact function and involvement in pigmentation is not clearly understood. Melanoma antigen recognized by T cells 1 has been shown to interact with the melanosomal proteins Pmel17 and OA1. To understand the function of MART-1 in pigmentation, we developed a new knockout mouse model. Mice deficient in MART-1 are viable, but loss of MART-1 leads to a coat color phenotype, with a reduction in total melanin content of the skin and hair. Lack of MART-1 did not affect localization of melanocyte-specific proteins nor maturation of Pmel17. Melanosomes of hair follicle melanocytes in MART-1 knockout mice displayed morphological abnormalities, which were exclusive to stage III and IV melanosomes. In conclusion, our results suggest that MART-1 is a pigmentation gene that is required for melanosome biogenesis and/or maintenance.

Association between white-coat effect and blunted dipping of nocturnal blood pressure.

In this study, we assessed whether the white-coat effect (difference between office and daytime blood pressure (BP)) is associated with nondipping (absence of BP decrease at night). Data were available in 371 individuals of African descent from 74 families selected from a population-based hypertension register in the Seychelles Islands and in 295 Caucasian individuals randomly selected from a population-based study in Switzerland. We used standard multiple linear regression in the Swiss data and generalized estimating equations to account for familial correlations in the Seychelles data. The prevalence of systolic and diastolic nondipping (<10% nocturnal BP decrease) and white-coat hypertension (WCH) was respectively 51, 46, and 4% in blacks and 33, 37, and 7% in whites. When white coat effect and nocturnal dipping were taken as continuous variables (mm Hg), systolic (SBP) and diastolic BP (DBP) dipping were associated inversely and independently with white-coat effect (P < 0.05) in both populations. Analogously, the difference between office and daytime heart rate was inversely associated with the difference between daytime and night-time heart rate in the two populations. These results did not change after adjustment for potential confounders. The white-coat effect is associated with BP nondipping. The similar associations between office-daytime values and daytime-night-time values for both BP and heart rate suggest that the sympathetic nervous system might play a role. Our findings also further stress the interest, for clinicians, of assessing the presence of a white-coat effect as a means to further identify patients at increased cardiovascular risk and guide treatment accordingly.

Prevalence of subfoveal nodules in Coat's disease

Purpose:Coats' disease is a non-hereditary condition characterized by idiopathic retinal telangiectasia, and exudative retinopathy. Although the exudation often spreads from the main areas of telangiectasia, there is a preferential accumulation of exudation in the macular area in Coats' disease. A subfoveal nodule has usually been described in the context of resolution of macular exudates after treatment of peripheral retinal telangiectasis. Nevertheless, a recent reports stressed out an uncommon prominent subfoveal nodule with peripheral exudates as initial presentation of Coats'disease. The purpose of this study was to report the prevalence of this presentation in a cohort of patients. Methods:All consecutive patients with Coats' disease referred to the Jules Gonin Eye Hospital between January 1979 and July 2006 were included. All charts were screened for a clear cut subfoveal circular lesion on fundus photographies at initial presentation. Results:95 patients suffering of Coat's disease were enrolled. 33 out of 95 patients had subtotal or total exudative retinal detachment, which impeded macular examination. 14 out of 62 (22.6%) resting patients presented with a clear cut prominent circular subfoveal lesion at initial presentation. All patients had unilateral disease. Mean age was 5.6 ± 3.5 year old at initial presentation. There were 4 females and 10 males. Pigmentation and size of the nodule were not homogenous. Mean diameter was 1.1 ± 0.5 optic disc diameter. Conclusions:The present study shows that subfoveal nodule is not such a rare primary presentation of Coats' disease in contrast to what it has been previously reported in the literature. Thus the initial finding of prominent subfoveal nodule associated with peripheral retinal findings made the diagnosis of Coats' disease highly likely.Physicians should be aware that a proeminent subfoveal nodule is a common initial presentation of Coats' disease as it can be confused clinically with Retinoblastoma.

Epidemiology of Masked and White-Coat Hypertension: The Family-Based SKIPOGH Study.

OBJECTIVE: We investigated factors associated with masked and white-coat hypertension in a Swiss population-based sample. METHODS: The Swiss Kidney Project on Genes in Hypertension is a family-based cross-sectional study. Office and 24-hour ambulatory blood pressure were measured using validated devices. Masked hypertension was defined as office blood pressure<140/90 mmHg and daytime ambulatory blood pressure≥135/85 mmHg. White-coat hypertension was defined as office blood pressure≥140/90 mmHg and daytime ambulatory blood pressure<135/85 mmHg. Mixed-effect logistic regression was used to examine the relationship of masked and white-coat hypertension with associated factors, while taking familial correlations into account. High-normal office blood pressure was defined as systolic/diastolic blood pressure within the 130-139/85-89 mmHg range. RESULTS: Among the 652 participants included in this analysis, 51% were female. Mean age (±SD) was 48 (±18) years. The proportion of participants with masked and white coat hypertension was respectively 15.8% and 2.6%. Masked hypertension was associated with age (odds ratio (OR) = 1.02, p = 0.012), high-normal office blood pressure (OR = 6.68, p<0.001), and obesity (OR = 3.63, p = 0.001). White-coat hypertension was significantly associated with age (OR = 1.07, p<0.001) but not with education, family history of hypertension, or physical activity. CONCLUSIONS: Our findings suggest that physicians should consider ambulatory blood pressure monitoring for older individuals with high-normal office blood pressure and/or who are obese.

Diverse set of Turing nanopatterns coat corneae across insect lineages.

Nipple-like nanostructures covering the corneal surfaces of moths, butterflies, and Drosophila have been studied by electron and atomic force microscopy, and their antireflective properties have been described. In contrast, corneal nanostructures of the majority of other insect orders have either been unexamined or examined by methods that did not allow precise morphological characterization. Here we provide a comprehensive analysis of corneal surfaces in 23 insect orders, revealing a rich diversity of insect corneal nanocoatings. These nanocoatings are categorized into four major morphological patterns and various transitions between them, many, to our knowledge, never described before. Remarkably, this unexpectedly diverse range of the corneal nanostructures replicates the complete set of Turing patterns, thus likely being a result of processes similar to those modeled by Alan Turing in his famous reaction-diffusion system. These findings reveal a beautiful diversity of insect corneal nanostructures and shed light on their molecular origin and evolutionary diversification. They may also be the first-ever biological example of Turing nanopatterns.

9C.09: TREATMENT WITH CANDESARTAN UNMASKS HIGHER URINARY NOREPINEPHRINE EXCRETION IN WHITE COAT HYPERTENSIVE PATIENTS COMPARED TO HEALTHY NORMOTENSIVE PARTICIPANTS.

OBJECTIVE: White coat hypertensive is a pre-hypertensive state that has been associated with increased sympathetic drive. The objective of the study was to compare the exposure of the kidney to sympathetic nerve activity using urinary normetanephrine (UNMN) as a marker of renal sympathetic exposure in white coat hypertensive (WCH) and healthy normotensive (HN) participants. DESIGN AND METHOD: This was a double-blind randomized placebo-controlled crossover study. WCH were included if office blood pressure was >140/80 mmHg and ambulatory blood pressure <135/85 mmHg and HN if OBP was <140/90 mmHg and ABP <135/85 mmHg Participants were randomized to receive either 16 mg of candesartan or a matched placebo for one week before study day. On the study day systemic and renal hemodynamics as well as plasma norepinephrine and urinary excretion of normetanephrine (measured by LC/MS-MS were measured after one hour of baseline, one hour of lower body negative pressure and one hour of recovery period. Excretion of UNMN was expressed as the total of UNMN excreted during these three hours (cumUNMN). Paired or unpaired t-test were used for comparison. RESULTS: 25 HN and 12 WCH participants were included in the study. Mean age (±standard deviation), BMI were respectively 31.0±10.5 years and 22.0 ± 2.2 Kg/m2 in HN and 40.7±17.8 years and 26.7 ± 6.3 Kg/m2 in WCH.Table 1 Baseline mean blood pressure, plasma noradrenaline and cumulated UNMN during placebo and candesartan(Figure is included in full-text article.)Mean blood pressure was higher during placebo and candesartan in WCH compared to HN. Cumulated UNMN was higher in both groups after candesartan treatment. Cumulated UNMN was higher in WCH than in HN only after candesartan treatment. CONCLUSIONS: Urinary excretion of normetanephrine is increased in WCH compared to HN when treated with candesartan. The increased excretion of uNMN when the renin angiotensin system is blocked might reflect an increased sensitivity of WCH to stress conditions such as orthostatic stress.

Epidemiology of masked and white-coat hypertension : the family-based SKIPOGH study

Un enregistrement de la tension artérielle ambulatoire (couvrant 24 heures) ainsi que plusieurs mesures en cabinet ont permis de classer chaque participant dans 4 catégories : normotension (tension artérielle normale au cabinet et en ambulatoire), hypertension artérielle soutenue (tension artérielle élevée au cabinet et en ambulatoire), hypertension de la blouse blanche (tension artérielle élevée au cabinet mais normale en ambulatoire) et hypertension artérielle masquée (tension artérielle élevée en ambulatoire mais normale au cabinet). Dans la littérature, la prévalence de l'hypertension artérielle masquée varie entre 8% et 48% selon la méthodologie utilisée et la population étudiée. Les personnes présentant une hypertension artérielle masquée ou une hypertension de la blouse blanche pourraient avoir un risque cardiovasculaire plus élevé que des personnes normotendues. Il est utile de déterminer les facteurs cliniques associés à l'hypertension artérielle masquée et à l'hypertension de la blouse blanche afin d'identifier les personnes à risque de développer ces conditions. Peu d'études ont examiné la proportion et les facteurs associés à l'hypertension artérielle masquée et à l'hypertension de la blouse blanche en Suisse, et aucune étude n'a été faite au niveau populationnel. Dans cette étude, nous investiguons les facteurs associés à l'hypertension masquée et à l'hypertension de la blouse blanche dans une étude populationnelle Suisse. Le Swiss Kidney Project on Genes in Hypertension (SKIPOGH) est une étude familiale transversale. La tension artérielle au cabinet et la tension artérielle ambulatoire sont mesurées par des appareils validés. Dans cette étude, nous avons défini l'hypertension artérielle masquée comme une tension artérielle au cabinet < 140/90 mmHg et une tension ambulatoire (jour) s 135/85 mmHg ; l'hypertension de la blouse blanche comme une tension artérielle au cabinet s 140/90 mmHg et une tension ambulatoire < 135/85 mmHg ; et enfin la tension artérielle à la limite supérieure de la norme au cabinet comme une tension systolique entre 130 et 139 mmHg et/ou une tension artérielle diastolique entre 85 et 89 mmHg lors de la mesure au cabinet. Nous avons utilisé une régression logistique multiple pour examiner la relation entre l'hypertension masquée et l'hypertension de la blouse blanche, d'une part, et les facteurs associés, d'autre part, en prenant en compte les corrélations familiales. Parmi les 652 participants inclus dans cette analyse, 51% sont des femmes. L'âge moyen (± écart type) est de 48 ans (± 18 ans). Les proportions de participants avec une hypertension masquée et une hypertension de la blouse blanche sont de 15.8% et de 2.6% respectivement. L'hypertension masquée est associée à l'âge (odds ratio (OR) = 1.02, p = 0.012), à une tension artérielle au cabinet à la limite supérieure de la norme (OR = 6.68, p, 0.001) et à l'obésité (OR = 3.63, p = 0.001). L'hypertension de la blouse blanche est associée à l'âge (OR = 1.07, p, 0.001) mais pas au niveau d'éducation, à l'anamnése familiale d'hypertension ou à l'activité physique. Nos données suggèrent que les médecins doivent envisager d'effectuer un enregistrement de la tension artérielle ambulatoire chez les personnes âgées avec une tension au cabinet à la limite supérieure de la norme et/ou chez les patients obèses afin de déterminer si ces individus présentent une hypertension artérielle en ambulatoire.

High-resolution magnetic resonance imaging quantitatively detects individual pancreatic islets.

OBJECTIVE-We studied whether manganese-enhanced high-field magnetic resonance (MR) imaging (MEHFMRI) could quantitatively detect individual islets in situ and in vivo and evaluate changes in a model of experimental diabetes.RESEARCH DESIGN AND METHODS-Whole pancreata from untreated (n = 3), MnCl(2) and glucose-injected mice (n = 6), and mice injected with either streptozotocin (STZ; n = 4) or citrate buffer (n = 4) were imaged ex vivo for unambiguous evaluation of islets. Exteriorized pancreata of MnCl(2) and glucose-injected mice (n = 6) were imaged in vivo to directly visualize the gland and minimize movements. In all cases, MR images were acquired in a 14.1 Testa scanner and correlated with the corresponding (immuno)histological sections.RESULTS-In ex vivo experiments, MEHFMRI distinguished different pancreatic tissues and evaluated the relative abundance of islets in the pancreata of normoglycemic mice. MEHFMRI also detected a significant decrease in the numerical and volume density of islets in STZ-injected mice. However, in the latter measurements the loss of beta-cells was undervalued under the conditions tested. The experiments on the externalized pancreata confirmed that MEHFMRI could visualize native individual islets in living, anesthetized mice.CONCLUSIONS-Data show that MEHFMRI quantitatively visualizes individual islets in the intact mouse pancreas, both ex vivo and in vivo. Diabetes 60:2853-2860, 2011

New inhibitors of Helicobacter pylori urease holoenzyme selected from phage-displayed peptide libraries.

Urease is an important virulence factor for Helicobacter pylori and is critical for bacterial colonization of the human gastric mucosa. Specific inhibition of urease activity has been proposed as a possible strategy to fight this bacteria which infects billions of individual throughout the world and can lead to severe pathological conditions in a limited number of cases. We have selected peptides which specifically bind and inhibit H. pylori urease from libraries of random peptides displayed on filamentous phage in the context of pIII coat protein. Screening of a highly diverse 25-mer combinatorial library and two newly constructed random 6-mer peptide libraries on solid phase H. pylori urease holoenzyme allowed the identification of two peptides, 24-mer TFLPQPRCSALLRYLSEDGVIVPS and 6-mer YDFYWW that can bind and inhibit the activity of urease purified from H. pylori. These two peptides were chemically synthesized and their inhibition constants (Ki) were found to be 47 microM for the 24-mer and 30 microM for the 6-mer peptide. Both peptides specifically inhibited the activity of H. pylori urease but not that of Bacillus pasteurii.

Task force IV: Clinical use of ambulatory blood pressure monitoring. Participants of the 1999 Consensus Conference on Ambulatory Blood Pressure Monitoring

OBJECTIVE: To reach a consensus on the clinical use of ambulatory blood pressure monitoring (ABPM). METHODS: A task force on the clinical use of ABPM wrote this overview in preparation for the Seventh International Consensus Conference (23-25 September 1999, Leuven, Belgium). This article was amended to account for opinions aired at the conference and to reflect the common ground reached in the discussions. POINTS OF CONSENSUS: The Riva Rocci/Korotkoff technique, although it is prone to error, is easy and cheap to perform and remains worldwide the standard procedure for measuring blood pressure. ABPM should be performed only with properly validated devices as an accessory to conventional measurement of blood pressure. Ambulatory recording of blood pressure requires considerable investment in equipment and training and its use for screening purposes cannot be recommended. ABPM is most useful for identifying patients with white-coat hypertension (WCH), also known as isolated clinic hypertension, which is arbitrarily defined as a clinic blood pressure of more than 140 mmHg systolic or 90 mmHg diastolic in a patient with daytime ambulatory blood pressure below 135 mmHg systolic and 85 mmHg diastolic. Some experts consider a daytime blood pressure below 130 mmHg systolic and 80 mmHg diastolic optimal. Whether WCH predisposes subjects to sustained hypertension remains debated. However, outcome is better correlated to the ambulatory blood pressure than it is to the conventional blood pressure. Antihypertensive drugs lower the clinic blood pressure in patients with WCH but not the ambulatory blood pressure, and also do not improve prognosis. Nevertheless, WCH should not be left unattended. If no previous cardiovascular complications are present, treatment could be limited to follow-up and hygienic measures, which should also account for risk factors other than hypertension. ABPM is superior to conventional measurement of blood pressure not only for selecting patients for antihypertensive drug treatment but also for assessing the effects both of non-pharmacological and of pharmacological therapy. The ambulatory blood pressure should be reduced by treatment to below the thresholds applied for diagnosing sustained hypertension. ABPM makes the diagnosis and treatment of nocturnal hypertension possible and is especially indicated for patients with borderline hypertension, the elderly, pregnant women, patients with treatment-resistant hypertension and patients with symptoms suggestive of hypotension. In centres with sufficient financial resources, ABPM could become part of the routine assessment of patients with clinic hypertension. For patients with WCH, it should be repeated at annual or 6-monthly intervals. Variation of blood pressure throughout the day can be monitored only by ABPM, but several advantages of the latter technique can also be obtained by self-measurement of blood pressure, a less expensive method that is probably better suited to primary practice and use in developing countries. CONCLUSIONS: ABPM or equivalent methods for tracing the white-coat effect should become part of the routine diagnostic and therapeutic procedures applied to treated and untreated patients with elevated clinic blood pressures. Results of long-term outcome trials should better establish the advantage of further integrating ABPM as an accessory to conventional sphygmomanometry into the routine care of hypertensive patients and should provide more definite information on the long-term cost-effectiveness. Because such trials are not likely to be funded by the pharmaceutical industry, governments and health insurance companies should take responsibility in this regard.