Platelet reactive conformation and multimeric pattern of von Willebrand factor in acquired thrombotic thrombocytopenic purpura during acute disease and remission

BACKGROUND

Binding of von Willebrand factor (VWF) multimers of ultra-large size to platelets is considered the triggering mechanism of microvascular thrombosis in thrombotic thrombocytopenic purpura (TTP).

OBJECTIVE

To assess the potential of VWF-related measurements as markers of disease activity and severity in TTP.

METHODS

VWF antigen (VWF:Ag), platelet glycoprotein-Ib-α binding-conformation (GPIb-α/BC) and multimeric pattern were investigated in 74 patients with acquired TTP during acute disease, remission or both and 73 healthy controls. In patients with both acute and remission samples available, VWF ristocetin co-factor activity (VWF:RCo) and collagen binding (VWF:CB) were also measured. The relationships of study measurements with the presence of acute disease and remission and with markers of disease severity were assessed.

RESULTS

VWF:Ag and VWF-GPIb-α/BC were higher in TTP patients than controls (P < 0.001 and 0.004). However, there was no statistically significant difference in VWF-GPIb-α/BC between samples obtained during acute TTP and remission. Larger VWF multimers were frequently lacking in acute TTP patients, who displayed ultra-large multimers at remission. The degree of loss of larger VWF multimers correlated with the degree of abnormality of hemoglobin, platelet counts and serum lactate dehydrogenase (LDH) and was associated with low levels of both VWF:RCo/Ag and VWF:CB/Ag ratios.

CONCLUSIONS

In TTP the platelet-binding conformation of VWF is not exclusively present in acute disease, nor is it associated with its clinical and laboratory severity. The loss of larger VWF multimers, accompanied by low VWF:RCo/Ag and VWF:CB/Ag ratio values, represents an index of disease activity and severity of acute TTP in patients with severe ADAMTS-13 deficiency.

Quantitative proteomic analysis of cold-responsive proteins in rice

Rice is susceptible to cold stress and with a future of climatic instability we will be unable to produce enough rice to satisfy increasing demand. A thorough understanding of the molecular responses to thermal stress is imperative for engineering cultivars, which have greater resistance to low temperature stress. In this study we investigated the proteomic response of rice seedlings to 48, 72 and 96 h of cold stress at 12-14°C. The use of both label-free and iTRAQ approaches in the analysis of global protein expression enabled us to assess the complementarity of the two techniques for use in plant proteomics. The approaches yielded a similar biological response to cold stress despite a disparity in proteins identified. The label-free approach identified 236 cold-responsive proteins compared to 85 in iTRAQ results, with only 24 proteins in common. Functional analysis revealed differential expression of proteins involved in transport, photosynthesis, generation of precursor metabolites and energy; and, more specifically, histones and vitamin B biosynthetic proteins were observed to be affected by cold stress.

Less label, more free: approaches in label-free quantitative mass spectrometry

In this review we examine techniques, software, and statistical analyses used in label-free quantitative proteomics studies for area under the curve and spectral counting approaches. Recent advances in the field are discussed in an order that reflects a logical workflow design. Examples of studies that follow this design are presented to highlight the requirement for statistical assessment and further experiments to validate results from label-free quantitation. Limitations of label-free approaches are considered, label-free approaches are compared with labelling techniques, and forward-looking applications for label-free quantitative data are presented. We conclude that label-free quantitative proteomics is a reliable, versatile, and cost-effective alternative to labelled quantitation.

Delayed Retrograde Type A Aotic Dissection After Endografting of Descending Thoracic Aorta

We report a case of a delayed retrograde dissection occurred after endovascular repair of ruptured type B aortic dissection. A 75-year-old male, presented with acute hemothorax and aortic arch fissuration. He was successfully treated with descending aorta and aortic arch stenting. After six days, he developed retrograde type A dissection with aortic root involvement and aortic valve incompetence. The entire ascending aorta and the ventral part of the arch were successfully replaced by a composite graft; in addition, aortic valve was replaced with prosthesis. Patient had an uncomplicated course and radiologic follow-up at one month revealed a sealed fissuration and no signs of endoleak. Endovascular repair of acute ruptured aorta, although life saving may be associated with potentially lethal complications, and it requires close monitoring with prolonged hospital stay to recognize and treat promptly these fatal complications.

Delayed retrograde type A aortic dissection after endografting of descending thoracic aorta

We report a case of a delayed retrograde dissection occurred after endovascular repair of ruptured type B aortic dissection. A 75-year-old male, presented with acute hemothorax and aortic arch fissuration. He was successfully treated with descending aorta and aortic arch stenting. After six days, he developed retrograde type A dissection with aortic root involvement and aortic valve incompetence. The entire ascending aorta and the ventral part of the arch were successfully replaced by a composite graft; in addition, aortic valve was replaced with prosthesis. Patient had an uncomplicated course and radiologic follow-up at one month revealed a sealed fissuration and no signs of endoleak. Endovascular repair of acute ruptured aorta, although life saving may be associated with potentially lethal complications, and it requires close monitoring with prolonged hospital stay to recognize and treat promptly these fatal complications.

Experimental protocol for activation-induced manganese-enhanced MRI (AIM-MRI) based on quantitative determination of Mn content in rat brain by fast T1 mapping

In activation-induced manganese-enhanced MRI (AIM-MRI) experiments, differential accumulation of Mn in activated and silent brain areas is generally assessed using T(1)-weighted images and quantified by the enhancement of signal intensity (SI), calculated with reference to SI before Mn administration or to SI of brain regions unaffected by the specific stimulus. However, SI enhancement can be unreliable when animals are removed from and reinserted into the magnet. We have developed an experimental protocol based on repeated intraperitoneal (i.p.) injections of Mn, quantitative determination of T(1), and coregistration of images to a rat brain atlas that allows absolute quantification of Mn concentration in selected brain areas. Results showed that interanimal variability of postcontrast T(1) values was very low (compared to the experimental error in T(1) determinations) allowing detection of differential regional Mn uptake in stimulated and unstimulated animals. In addition we have determined in vivo relaxivity of Mn in brain tissue and its frequency dependence.

Polymer gels for in-phantom dose imaging in radiotherapy

Normoxic polymer gel dosimeters are studied, with the aim of achieving a valid and advantageous method for in-phantom 3D dose determinations. Developments were carried out in the application of such dosimetric material to the method based on dosimeter gel layers that has shown good reliability for absorbed dose imaging in radiotherapy. The technique has been improved, in particular taking care of minimizing the oxygen infiltration into the gel matrix in order to suitably avoid its effect of inhibiting the polymerization process after exposure. A suitable choice of the material of dosimeter walls has brought to achieve good steadiness in time of dosimeter sensitivity and satisfactory results in dose imaging and depth-dose profiling.

Upper-rim CMPO-substituted calix[6]- and calix[8]arene extractants for the An3+/Ln3+separation from radioactive waste

Two new ligands (1and2) for actinide/lanthanide separation derived from calix[6]- and calix[8]arenes functionalised at the upper rim with six or eight CMPO binding units were synthesised. These ligands, having a methoxy group at the lower rim, are conformationally mobile in solution at room temperature. Extraction data from water to a NPHE/n-octanol (90/10) solution of ligands1and2, in the presence of bromo-cosan as synergist, show that these derivatives are less efficient and selective than the previously reported homologues derived from calix[4]arenes or from the lower rim CMPO calix[6]- and calix[8]arenes, especially at high nitric acid concentrations. However, although compound1and2do not appear promising for the actinide/lanthanide separation from high acidity radioactive waste, the results obtained in this work disclose some important structural results which can be useful for the design of new efficient and selective polytopic ligands.

Unconventional nonequilibrium dynamics in Ni10 magnetic molecules: evidence from NMR

Crystals containing Ni10 magnetic molecules display an unprecedented form of out-of-equilibrium behavior of the bulk magnetization M at temperatures as high as 17 K. We have performed 1H NMR measurements to probe the local Ni magnetic moments and their dynamics. It is apparent that no freezing of the Ni moments occurs, in striking contrast to what is observed in blocked superparamagnetic systems. The average local moments display the same behavior as M, thus unambiguously demonstrating the intrinsic character of the phenomenon. This result supports the hypothesis that the slowing down of M is due to a resonant phonon trapping mechanism which prevents the thermalization of M but not the fast spin flippings of the individual molecular moments. Indeed, the measured nuclear spin-lattice relaxation rate points to fast single-molecule dynamics at low temperature.

Semen anomalies due to voiding defects of the ampullo-vesicular tract. Infertility due to ampullo-vesicular voiding defects

Anatomical (congenital or postinflammatory) or functional anomalies of the uroseminal intersection can induce a voiding dysfunction of the deferential ampullae and seminal vesicles, leading to infertility. In case of azoospermia or OAT-syndrome with poor semen volume and decreased vesicular markers, some clinical history and examination data can cause suspect of one of such anomalies. The transrectal ultrasonographic findings of anechoic area(s) inside the prostate and/or seminal vesicle (even after recent ejaculation), the peculiar vasovesiculographic pictures (especially after ejaculation following the contrast medium injection into the vasa deferentia), plus the evaluation of the "deferential-ampullary sperm reserve", will permit a detailed diagnosis of the voiding dysfunction of the uroseminal crossing. A successful appropriate treatment of these pathologies can be done. Ultrasonically-guided transrectal puncture, or transurethral incision upstream of (or resection of) the ejaculatory duct orifices, or prolonged sexual abstinence, or artificial spermatocele of the vas deferens, or sperm recovering from urine for GIFT or IVF/ET after washing-out of the seminal tract by vas puncture are all methods, which can be selectively used depending on the individual case, to treat these forms of infertility. The authors present some paradigmatic clinical cases, and report that this pathology presumably occurs in up to 9% of non-selected infertile patient population.

Dysglycaemia in non-diabetic hypertensive patients: comparison of the impact of two different classifications of impaired fasting glucose on the cardiovascular risk profile

The clinical correlates and risk profile of prediabetes (fasting plasma glucose (FPG) values in the upper normal limits but below the diabetic threshold) in hypertension, an insulin-resistant, prodiabetogenic condition, are scarcely known. For this reason, we evaluated 982 non-diabetic (FPG,<126 mg 100 ml(-1) and no antidiabetic treatment) referred hypertensive patients without a history of cardiovascular disease grouped by mild (100-109 mg 100 ml(-1)) and advanced (110-125 mg 100 ml(-1)) dysglycaemia compared with normal FPG (<100 mg 100 ml(-1)). FPG, total and high density lipoprotein (HDL) cholesterol, triglycerides and total white blood cell count were assessed by standard methodologies; 10-year predicted coronary heart disease (CHD) risk was approximated by the Framingham risk score (FRS). Metabolic syndrome (MetS) was diagnosed by standard categorical criteria using either 110 or 100 mg 100 ml(-1) as a threshold for impaired fasting glucose (IFG). FPG was above 110 in 13% and between 100 and 109 in 20% of patients. In both dysglycaemic groups, perturbed glucose homeostasis was associated with abnormally high fasting triglycerides, low HDL cholesterol, obesity, worse CHD risk profile and higher white blood cell count. MetS was highly prevalent and its distribution pattern was markedly influenced by the definitions of IFG based on different FPG cutoffs. Thus, even mildly perturbed glucose homeostasis associates with atherogenic dyslipidaemia, obesity and adverse risk profile in non-diabetic hypertensive patients. Because of its prediabetic nature, dysglycaemia should prompt measures to prevent new-onset diabetes, although the role of IFG as an independent risk factor awaits specifically designed intervention trials.

Modeling proliferative tissue growth: a general approach and an avian case study

During development, tissues often undergo rapid physical expansion due to cell proliferation. Continuous and discrete models of one- and two-dimensional tissue growth are developed and applied to observational data of the developing avian gut, where the gut tissue cells undergo dramatic proliferation. The discrete cellular automata model provides results at the level of individual cells that reflect a realistic stochasticity and nonuniformity expected in cellular systems. Averaging the discrete results predicts population-level properties of the system, which match those of the continuous model. This dual approach provides an understanding of the interaction between the individual-level and population-level aspects of a developmental growth process. Both models are applied to a case study involving the developing intestinal tract of a quail embryo. A nonuniform growth model accurately predicts the positions of measurable biological landmarks within the growing tissue. Furthermore, the discrete model provides a framework for modeling the interactions between growing tissues and other biological mechanisms, such as cell motility and proliferation on an expanding tissue.