Somatic mosaicism in B cells of a patient with autosomal dominant hyper IgE syndrome

Hyper IgE syndrome (HIES) is characterized by recurrent skin abscesses, eczema, pneumonia, and high levels of serum IgE. Nonimmunologic manifestations of HIES include a characteristic face, pathologic dentition, scoliosis, bone alterations, hyperextensible joints, and vascular abnormalities. Somatic mosaicism is defined by the presence of two or more populations of cells with different genotypes in one individual. In this report, we describe one patient with classical HIES and another patient with a mild phenotype, both harboring the same genetic mutation. The patient with a mild phenotype did not present the characteristic face, had normal production of IL‐17A by T CD4⁺ cells, but had low phosphorylation of STAT‐3 in B cells. Interestingly, the mutation found in B cells was absent in other cell types analyzed, in agreement with the presence of a somatic mosaic genotype. The clinical and functional differences observed between these patients justify the use of complementary tools for a better definition of the cases. These approaches allow for a better understanding of complex phenotypes associated with somatic mosaicisms, and present the possibility to analyze the role of B lymphocytes in the pathophysiology of this disease. This knowledge has an impact on not only the treatment but also the provision of appropriate genetic counseling.     

Metabolic syndrome and risk for incident Alzheimer's disease or vascular dementia: the Three-City Study

OBJECTIVE—Associations between metabolic syndrome and its individual components with risk of incident dementia and its different subtypes are inconsistent.RESEARCH DESIGN AND METHODS—The 7,087 community-dwelling subjects aged ≥65 years were recruited from the French Three-City (3C) cohort. Hazard ratios (over 4 years) of incident dementia and its subtypes (vascular dementia and Alzheimer''s disease) and association with metabolic syndrome (defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria) and its individual components (hypertension, large waist circumference, high triglycerides, low HDL cholesterol, and elevated fasting glycemia) were estimated in separate Cox proportional hazard models.RESULTS—Metabolic syndrome was present in 15.8% of the study participants. The presence of metabolic syndrome increased the risk of incident vascular dementia but not Alzheimer''s disease over 4 years, independent of sociodemographic characteristics and the apolipoprotein (apo) Eɛ4 allele. High triglyceride level was the only component of metabolic syndrome that was significantly associated with the incidence of all-cause (hazard ratio 1.45 [95% CI 1.05–2.00]; P = 0.02) and vascular (2.27 [1.16–4.42]; P = 0.02) dementia, even after adjustment of the apoE genotype. Diabetes, but not impaired fasting glycemia, was significantly associated with all-cause (1.58 [1.05–2.38]; P = 0.03) and vascular (2.53 [1.15–5.66]; P = 0.03) dementia.CONCLUSIONS—The observed relation between high triglycerides, diabetes, and vascular dementia emphasizes the need for detection and treatment of vascular risk factors in older individuals in order to prevent the likelihood of clinical dementia.Dementia is the most severe form of pathological brain aging, defined by the coexistence of memory disorders and deficit in at least one other cognitive function (impairment of abstract thinking; impaired judgment; other disturbances of higher cortical function, such as aphasia, apraxia, agnosia, or constructional difficulty; or personality change), with a significant impact on activities of daily living (1). Eighteen percent of people aged >75 years have dementia. Its most frequent form is Alzheimer''s disease (∼50–60% of cases) ([1]), vascular dementia accounting for most of the other causes (1). The underlying pathophysiological mechanisms, and hence risk factors, of Alzheimer''s disease and vascular dementia remain uncertain (2), and no etiologic treatment is available yet. Nevertheless, several potentially modifiable risk factors of dementia have been identified. Hypertension, especially in mid-life, increases the likelihood of developing dementia (3). Although less studied, obesity (4) and dyslipidemia (5) are also being recognized as possible modifiable risk factors of dementia. Some studies have shown that diabetes increases the risk of developing dementia (6). These factors usually coexist under the heading of metabolic syndrome, which is a cluster of five cardiovascular risk factors including hypertension, abdominal obesity, high triglycerides, low HDL cholesterol, and elevated fasting glycemia (impaired fasting glucose or diabetes) (7).Metabolic syndrome is associated with increased risk of cardiovascular disease (8). If metabolic syndrome were also associated with increased risk of developing dementia, the screening and management of its components might offer avenues for prevention of cardiovascular disease and dementia as well. However, the association between metabolic syndrome, or its individual components, and dementia has received little attention (9–14). Three longitudinal studies (10–12) showed that metabolic syndrome as a whole is related to higher risk of cognitive decline, but they did not examine the association with the risk of dementia. While a cross-sectional study (13) found a higher prevalence of dementia in women with metabolic syndrome, the single published prospective study (14) showed no association between metabolic syndrome and incident dementia. On the other hand, only some components of the metabolic syndrome (and not the metabolic syndrome itself) might be associated with an increased risk of incident dementia. In particular, several prospective studies evidenced that the presence of diabetes was associated with increased incidence of Alzheimer''s disease and vascular dementia (6,14). However, the role of hyperglycemia in the absence of diabetes (impaired fasting glucose) needs to be well defined (15).We therefore aimed to estimate the prospective association between metabolic syndrome, or its individual components, with the risk of incident dementia and the potential differences according to the subtype of dementia: Alzheimer''s disease or vascular dementia, in a large prospective epidemiological study conducted in community-dwelling older subjects. We focused on the component “elevated fasting glycemia” to study the specific role of diabetes versus impaired fasting glucose.     

Prospective measurements of dehydroepiandrosterone sulfate in a cohort of elderly subjects: Relationship to gender, subjective health, smoking habits, and 10-year mortality

The decrease with age of the adrenal-secreted dehydroepiandrosterone sulfate (DHEAS) in serum has suggested that it may be causally related to longevity. For the PAQUID [People (Personnes) Aged (Agées) About What (Quid, in Latin)] cohort of elderly subjects, we have previously reported higher DHEAS in men than in women, a decrease with age and, among men, a negative correlation between the DHEAS level and mortality at 2 and 4 years. Here, with an 8-year followup in 290 subjects, we show a global decrease of 2.3% per year for men and 3.9% per year for women. However, in approximately 30% of cases, there was an increase of DHEAS. We observed no relationship between the evolution of DHEAS level and functional, psychological, and mental status, possibly because of selection by death. In women, no association was found between mortality and DHEAS level. In men, the relative risk (RR) of death was higher for the lowest levels of DHEAS (RR = 1.9, P = 0.007), with RR = 6.5, P = 0.003 for those under 70 years old, a result indicating heterogeneity of the population. There was an effect of subjective health on mortality that disappeared after adjustment of DHEAS levels, suggesting its relation with these DHEAS levels. Death RR was much higher in smokers with a low DHEAS level than in nonsmokers with high DHEAS (RR = 6.7, P = 0.001). We submit that the involvement of DHEAS is possibly different according to gender, that association between low DHEAS level and mortality only for men under 70 years old possibly reflects heterogeneity of the population, and that DHEAS level is a reliable predictor of death in male smokers.     

Theoretical analysis of the effect of imperfect slice profiles on tagging schemes for pulsed arterial spin labeling MRI.

Pulsed arterial spin labeling (ASL) techniques provide a noninvasive method of obtaining qualitative and quantitative perfusion images with MRI. ASL techniques employ inversion recovery and/or saturation recovery to induce perfusion weighting, and thus the performance of these techniques is dependent on the slice profiles of the inversion or saturation pulses. This article systematically examines through simulations the effects of slice profile imperfections on the perfusion signal for nine labeling schemes, including FAIR, FAIRER, and EST (UNFAIR). Each sequence is evaluated for quantitative accuracy, suppression of stationary signal, and magnitude of perfusion signal. Perfusion effects are modeled from a modified Bloch equation and experimentally determined slice profiles. The results show that FAIR, FAIRER, and EST have excellent tissue suppression. The magnitude of the perfusion signal is comparable for FAIR and FAIRER, with EST providing a slightly weaker signal. For quantitative measurements, all three methods underestimate the perfusion signal by more than 20%. Of the additional six ASL techniques examined, only one performed well in this model. This method, which combines inversion and saturation recovery, yields improved signal accuracy (<15% difference from the theoretical value) and tissue suppression similar to that of FAIR and its variants, but has only half the signal. Magn Reson Med 46:141-148, 2001.     

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold’s surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.     

Hospital infection caused by non-typable Staphylococcus aureus: application of reverse typing.

Hospital infections caused by strains of Staphylococcus aureus non-typable (NT) by phages have occurred in three Spanish hospitals since 1981. Reverse typing allowed characterization of the strains in all three cases.     

Successful endoscopic transection of a partially obstructing antral diaphragm

A 14-yr-old girl presented with long-standing symptoms of partial gastric outlet obstruction due to an antral mucosal diaphragm that had a central aperture of 4-5 mm. The literature of this congenital malformation is reviewed with respect to diagnostic criteria and feasibility of endoscopic transection. The procedure and outcome of this first successful endoscopic transection of a partially obstructing antral diaphragm are reported.     

Effects of graded perfusion and isovolumic work on epicardial and venous adenosine and cytosolic metabolism

Epicardial adenosine levels and venous adenosine release were measured in isovolumically contracting (ISO) and empty non-isovolumic (non-ISO) guinea-pig hearts subjected to graded perfusion (approximately 7.5, 5.5, 4.0, 2.0, and 1.0 ml/min/g). Myocardial metabolism was monitored using 31P-NMR spectroscopy. At flows of 5.5 ml/min/g or higher epicardial adenosine levels were stable and comparable in ISO and non-ISO hearts (approximately 160 nM). At flows of 4.0 ml/min/g or higher venous adenosine release was stable and comparable in ISO and non-ISO hearts (approximately 30 pmol/min/g). At lower flows, epicardial adenosine and venous adenosine release both increased and were significantly higher in ISO hearts, compared to non-ISO hearts, at each flow rate. Whereas epicardial adenosine increased linearly in ISO and non-ISO hearts at low flows, venous adenosine release stabilized in ISO hearts perfused at 1.0 ml/min/g. Epicardial adenosine, venous adenosine release, and log [ATP]/[ADP] [Pi] all displayed significant correlations with the O2 supply:demand ratio which were comparable in ISO and non-ISO hearts. Elevated levels of epicardial adenosine were linearly related to log [ATP]/[ADP] [Pi] and cytosolic [AMP] and these relationships were comparable in ISO and non-ISO hearts. Alternatively, changes in venous adenosine release did not display simple relationships with log [ATP]/[ADP] [Pi] and cytosolic [AMP] and they were not comparable in ISO and non-ISO hearts. The data indicate that: (i) myocardial adenosine formation increases only below a metabolic threshold corresponding to log [ATP]/[ADP] [Pi] = 5.0 and O2 supply:demand = 1.5 in ISO and non-ISO guinea-pig hearts; (ii) stimulated epicardial adenosine levels appear to be consistently related to changes in cytosolic metabolism below this threshold in ISO and non-ISO hearts; (iii) more complex relationships exist between venous adenosine release and myocardial metabolism during graded perfusion, possibly reflecting the variety of factors modulating venous adenosine release.