Structural description of pressure-induced amorphization in ZrW2O8.

ZrW2O8 undergoes a high-pressure amorphization transition above 1.5 GPa to a phase which is recoverable to ambient conditions. Reverse Monte Carlo modeling of neutron and x-ray total scattering data from ZrW2O8 recovered from approximately 4 GPa shows that the large increase in density on pressurizing ZrW2O8 is accommodated within the structure by increased bonding between the WO4 tetrahedra.

Diagnostic utility of S100A1 expression in renal cell neoplasms: an immunohistochemical and quantitative RT-PCR study.

S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed.

Role of molecular markers in diagnosis and prognosis of renal cell carcinoma.

It has been demonstrated that different renal cell neoplasms have characteristic morphologic and genetic features. Histologic subtyping of renal epithelial neoplasms has been shown to be of prognostic value; therefore they must be correctly classified. Although adequate sampling and a good understanding of the morphologic features usually minimize diagnostic errors, the use of immunohistochemical and chromosomal analysis on formalin-fixed, paraffin-embedded tissues can be necessary.

Chromosomal gains in the sarcomatoid transformation of chromophobe renal cell carcinoma.

The hallmark of chromophobe renal cell carcinoma is multiple chromosomal losses from among chromosomes 1, 2, 6, 10 and 17. Chromophobe renal cell carcinoma with distant metastases or sarcomatoid transformation are uncommon and little is known about their chromosomal abnormalities. We collected six sarcomatoid chromophobe renal cell carcinomas and three primary chromophobe renal cell carcinomas with distant metastases.

Inhibition of Na+/K+ ATPase potentiates synaptic transmission in tactile sensory neurons of the leech.

Increasing evidence indicates that modulation of Na(+)/K(+) ATPase activity is involved in forms of neuronal and synaptic plasticity. In tactile (T) neurons of the leech Hirudo medicinalis, Na(+)/K(+) ATPase is the main determinant of the afterhyperpolarization (AHP), which characterizes the firing of these mechanosensory neurons. Previously, it has been reported that cAMP (3',5'-cyclic adenosine monophosphate), which mediates the effects of serotonin (5HT) in some forms of learning in the leech, negatively modulates Na(+)/K(+) ATPase activity, thereby reducing the AHP amplitude in T neurons.

Long-term results of aortic valve replacement with Edwards Prima Plus stentless bioprosthesis: eleven years' follow up.

Background And Aim Of The Study: The Edwards Lifesciences Prima Plus stentless valve (ELSV) is a bioprosthesis manufactured from a porcine aortic root. The study aim was to evaluate late clinical outcomes after aortic valve replacement (AVR) with ELSV implanted as a miniroot in patients with aortic valve disease.

Methods: Between 1993 and 2004, 318 patients (232 males, 86 females; mean age 69 +/- 9 years; range: 37-83 years) underwent AVR with the ELSV.

Acetyl-L-carnitine affects nonassociative learning processes in the leech Hirudo medicinalis.

Acetyl-L-carnitine is a natural molecule widely distributed in vertebrate and invertebrate nervous system. It is known to have significant effects on neuronal activity playing a role as neuroprotective and anti-nociceptive agent, as well as neuromodulatory factor. About its capability of affecting learning processes the available data are controversial.

Structures of (S)-(-)-4-oxo-2-azetidinecarboxylic acid and 3-azetidinecarboxylic acid from powder synchrotron diffraction data.

The crystal structures of the four-membered heterocycles (S)-(-)-4-oxo-2-azetidinecarboxylic acid (I) and 3-azetidinecarboxylic acid (II) were solved by direct methods using powder synchrotron X-ray diffraction data. The asymmetry of the oxoazetidine and azetidine rings is discussed, along with the hydrogen bonding.

C242T polymorphism in CYBA gene (p22phox) and risk of coronary artery disease in a population of Caucasian Italians.

Background: specific polymorphisms of genes regulating intracellular redox balance and oxidative stress are related to atherogenesis. Some studies have identified a relationship between progression of atherosclerosis and C242T mutation in CYBA gene coding for p22phox, a subunit of the NADH/NADPH oxidase system.

Design: we investigated whether the C242T nucleotide transition is associated with the presence of coronary artery disease (CAD) in a population of 494 Caucasian Italians undergoing coronary angiography to diagnose the cause of chest pain.

X-ray illumination induced Fe(II) spin crossover in the Prussian blue analogue cesium iron hexacyanochromate.

The effect of X-ray illumination on the structural properties of the mixed valence Prussian blue analogue CsFe(II)[Cr(III)(CN)6] has been studied by time-dependent high-resolution synchrotron X-ray diffraction. Abrupt isosymmetric phase transitions, accompanied by dramatic volume collapse, were found in the temperature range 245-265 K, induced by sudden Fe(II) spin transitions from the high spin (HS) (4t(2g)2e(g), S = 2) to the low spin (LS) (6t(2g)0e(g), S = 0) configuration. Absorption of X-ray photons generates photoexcited Fe(II)(LS) domains whose size rapidly grows with time until the percolation threshold is reached and the structure collapse is triggered.

Oncocytic papillary renal cell carcinoma: a clinicopathologic, immunohistochemical, ultrastructural, and interphase cytogenetic study of 12 cases.

Papillary renal cell carcinoma (RCC) is subclassified in type 1 displaying cells with scanty pale cytoplasm arranged in a single layer and in type 2 showing pseudostratified cells with eosinophilic cytoplasm. However, the existence of more variants of papillary RCC may be inferred by the recognition of few cases with different morphological features. We report the clinicopathologic, immunohistochemical, ultrastructural, and interphase cytogenetic features of 12 papillary RCC composed by oncocytes.

Prognostic role of the histologic subtypes of renal cell carcinoma after slide revision.

Objectives: To evaluate concordance, using the kappa statistic, between tumour histotypes assigned at initial diagnosis and those after slide revision, and to assess the independent predictive value of reviewed tumour histotype.

Materials And Methods: We analysed records of 491 patients who had undergone partial or radical nephrectomy for renal cell carcinoma (RCC) in our department from 1986 to 2000. Pathologic slides were reviewed by one uropathologist blinded to original diagnoses and follow-up data, who reassigned histologic subtype and nuclear grades.

Acquired cystic disease-associated renal tumors: an immunohistochemical and fluorescence in situ hybridization study.

End-stage renal disease is associated with an increased incidence of renal cell neoplasms. Among these, recent studies have identified tumors with unusual histological patterns that do not fit into the categories recognized in the current classification system. These tumors often occur in kidneys with acquired cystic disease and are composed mainly of large eosinophilic cells arranged in solid, cribriform, acinar, or papillary patterns.

Renal mucinous tubular and spindle carcinoma lacks the gains of chromosomes 7 and 17 and losses of chromosome Y that are prevalent in papillary renal cell carcinoma.

Mucinous tubular and spindle cell carcinoma of the kidney is an uncommon, distinctive neoplasm characterized by the proliferation of cuboidal and spindle cells arranged in tubular or sheet-like arrays, typically with a mucinous or myxoid background. The most important differential diagnostic consideration of mucinous tubular and spindle cell carcinoma is papillary renal cell carcinoma, type 1, with sarcomatoid transformation. The aim of our study is to investigate the pattern of possible gains or losses of chromosomes 7, 17 and Y in 10 mucinous tubular and spindle cell carcinomas with interphase fluorescence in situ hybridization (FISH).

Acetyl-L-carnitine up-regulates expression of voltage-dependent anion channel in the rat brain.

Acetyl-L-carnitine (ALC) exerts unique neuroprotective, neuromodulatory, and neurotrophic properties, which play an important role in counteracting various pathological processes, and have antioxidative properties, protecting cells against lipid peroxidation. In this study, suppression subtractive hybridization (SSH) method was applied for the generation of subtracted cDNA libraries and the subsequent identification of differentially expressed transcripts after treatment of rats with ALC. The technique generates an equalized representation of differentially expressed genes irrespective of their relative abundance and it is based on the construction of forward and reverse cDNA libraries that allow the identification of the genes that are regulated after ALC treatment.

Molecular genetic evidence for the independent origin of multifocal papillary tumors in patients with papillary renal cell carcinomas.

Purpose: In patients with papillary renal cell carcinoma, it is not uncommon to find two or more anatomically distinct and histologically similar tumors at radical nephrectomy. Whether these multiple papillary lesions result from intrarenal metastasis or arise independently is unknown. Previous studies have shown that multifocal clear cell renal cell carcinomas express identical allelic loss and shift patterns in the different tumors within the same kidney, consistent with a clonal origin.

Role for calcium signaling and arachidonic acid metabolites in the activity-dependent increase of AHP amplitude in leech T sensory neurons.

Previous studies have revealed a new form of activity-dependent modulation of the afterhyperpolarization (AHP) in tactile (T) neurons of the leech Hirudo medicinalis. The firing of T cells is characterized by an AHP, which is mainly due to the activity of the Na+/K+ ATPase. Low-frequency repetitive stimulation of T neurons leads to a robust increment of the AHP amplitude, which is correlated with a synaptic depression between T neuron and follower cells.

Computational model of touch sensory cells (T Cells) of the leech: role of the afterhyperpolarization (AHP) in activity-dependent conduction failure.

Bursts of spikes in T cells produce an AHP, which results from activation of a Na+/K+ pump and a Ca2+-dependent K+ current. Activity-dependent increases in the AHP are believed to induce conduction block of spikes in several regions of the neuron, which in turn, may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we used the neurosimulator SNNAP to develop a multi-compartmental model of the T cell.

Temperature effects on the hydrogen-bond patterns in 4-piperidinecarboxylic acid.

A temperature-controlled X-ray powder diffraction experiment, complemented with TGA and DSC analysis, allowed us to follow changes in the molecular conformation and hydrogen-bond patterns of 4-piperidinecarboxylic acid. The presence of three phases is confirmed. Phase 1 represents the monohydrated form of 4-piperidinecarboxylic acid, which exists from room temperature to 359 K, where dehydration occurs.

Original and reviewed nuclear grading according to the Fuhrman system: a multivariate analysis of 388 patients with conventional renal cell carcinoma.

Background: The objective of the current study was to evaluate the reproducibility of the Fuhrman nuclear grading system as well as its independent predictive value in a series of patients with conventional renal cell carcinoma (RCC).

Methods: The authors selected 388 patients who had undergone surgical treatment for conventional RCC between 1986 and 2000. Pathology slides from the selected patients were reviewed by a single pathologist, who reassigned a Fuhrman nuclear grade and assessed the presence of tumor necrosis.

Suitability of stentless bioprostheses for combined replacement of the aortic valve and ascending aorta.

Background: The Edwards Prima stentless valve (EPSV) is a bioprosthesis made of the porcine aortic root which, owing to its versatility, may be implanted with different techniques depending on the underlying disease. The aim of this study was to demonstrate the usefulness of the EPSV implanted as a miniroot in patients with disease of the aortic valve and ascending aorta.

Methods: Between January 1998 and July 2002, 91 patients (mean age 67 +/- 7 years) underwent combined replacement of the aortic valve and ascending aorta with an EPSV for aortic stenosis (n = 12), incompetence (n = 45) or mixed disease (n = 26); all had aneurysmal dilation of the ascending aorta and 8 had an acute aortic dissection.

Identification of differentially expressed genes induced in the rat brain by acetyl-L-carnitine as evidenced by suppression subtractive hybridisation.

Acetyl-L-carnitine (ALC) is a molecule widely present in the central nervous system (CNS) formed by the reversible acetylation of carnitine. It acts by stimulating energy metabolism. Reported neurobiological effects of this substance include modulation of brain energy and phospholipid metabolism; cellular macromolecules (including neurotrophic factors and neurohormones); synaptic transmission of multiple neurotransmitters.

Li4C60: a polymeric fulleride with a two-dimensional architecture and mixed interfullerene bonding motifs.

All known fullerene polymers have interfullerene connections via either [2 + 2] cycloaddition or single C-C bonds. The high-resolution synchrotron X-ray powder diffraction technique was employed here to determine the crystal structure of the Li4C60 fulleride. We find that the ground state of Li4C60 is a two-dimensional polymer with monoclinic crystal symmetry and an unprecedented architecture, combining both the [2 + 2] cycloaddition and the single C-C bridging motifs.

[The influence of the supine and prone positions in the esophageal pH monitoring in very low birth weight infants].

Background: Scarce information is available on the effects of body's positioning in the number and the duration of gastroesophageal reflux episodes in very low birth weight infants.

Aim: To evaluate the influence of prone compared to supine positions on the frequency and duration of acid gastroesophageal reflux episodes in very low birth weight infants and study the role of body position in the occurrence of exams with reflux index > or = 5% and > or = 10%.

Methods: Sixty one prolonged esophageal pH monitoring exams were retrospectively analyzed.