MALDI Mass Spectrometry Imaging of N-Linked Glycans in Cancer Tissues.

Glycosylated proteins account for a majority of the posttranslation modifications of cell surface, secreted, and circulating proteins. Within the tumor microenvironment, the presence of immune cells, extracellular matrix proteins, cell surface receptors, and interactions between stroma and tumor cells are all processes mediated by glycan binding and recognition reactions. Changes in glycosylation during tumorigenesis are well documented to occur and affect all of these associated adhesion and regulatory functions. A MALDI imaging mass spectrometry (MALDI-IMS) workflow for profiling N-linked glycan distributions in fresh/frozen tissues and formalin-fixed paraffin-embedded tissues has recently been developed. The key to the approach is the application of a molecular coating of peptide-N-glycosidase to tissues, an enzyme that cleaves asparagine-linked glycans from their protein carrier. The released N-linked glycans can then be analyzed by MALDI-IMS directly on tissue. Generally 40 or more individual glycan structures are routinely detected, and when combined with histopathology localizations, tumor-specific glycans are readily grouped relative to nontumor regions and other structural features. This technique is a recent development and new approach in glycobiology and mass spectrometry imaging research methodology; thus, potential uses such as tumor-specific glycan biomarker panels and other applications are discussed.

Cortical surface area and cortical thickness in the precuneus of adult humans.

The precuneus has received considerable attention in the last decade, because of its cognitive functions, its role as a central node of the brain networks, and its involvement in neurodegenerative processes. Paleoneurological studies suggested that form changes in the deep parietal areas represent a major character associated with the origin of the modern human brain morphology. A recent neuroanatomical survey based on shape analysis suggests that the proportions of the precuneus are also a determinant source of overall brain geometrical differences among adult individuals, influencing the brain spatial organization. Here, we evaluate the variation of cortical thickness and cortical surface area of the precuneus in a sample of adult humans, and their relation with geometry and cognition. Precuneal thickness and surface area are not correlated. There is a marked individual variation. The right precuneus is thinner and larger than the left one, but there are relevant fluctuating asymmetries, with only a modest correlation between the hemispheres. Males have a thicker cortex but differences in cortical area are not significant between sexes. The surface area of the precuneus shows a positive allometry with the brain surface area, although the correlation is modest. The dilation/contraction of the precuneus, described as a major factor of variability within adult humans, is associated with absolute increase/decrease of its surface, but not with variation in thickness. Precuneal thickness, precuneal surface area and precuneal morphology are not correlated with psychological factors such as intelligence, working memory, attention control, and processing speed, stressing further possible roles of this area in supporting default mode functions. Beyond gross morphology, the processes underlying the large phenotypic variation of the precuneus must be further investigated through specific cellular analyses, aimed at considering differences in cellular size, density, composition, and structural covariance compared to other brain areas.

Kidney-limited thrombotic microangiopathy in patients with SLE treated with romiplostim.

We present the case of a 19 year-old Caucasian female with history of systemic lupus erythematosus (SLE) and normal baseline kidney function who developed severe acute renal failure following treatment of thrombocytopenia with the thrombopoietic agent romiplostim. Percutaneous kidney biopsy revealed thrombotic microangiopathy (TMA) without immune complex lupus glomerulonephritis. We discuss pathogenesis and differential diagnosis of TMA in patients with SLE and raise concerns regarding the use of thrombopoietic agents in such patients. Based on favorable long-term outcome in our case aggressive treatment and in particular prolonged use of plasma exchange in these patients are advocated.

Preliminary baropodometric analysis of young soccer players while walking: geometric morphometrics and comparative evaluation.

AIM: The plantar support and its modifications are widely studied because of their bearing on posture. In particular, past studies have focused on the support modification during specific athletic tasks to highlight the eventual correlations between foot type and the most frequent sport injuries, due to intrinsic and extrinsic components that involve the structural and functional dynamics that act on the plantar vault during static and dynamic condition. These studies have been conducted by analyzing the morphological variation of the footprint during the performance. METHODS: In the present study the variation in shape of the baropodometrical footprint of young soccer players, has been analyzed using geometric morphometrics. This approach permits a quantification of the morphological variation of the subjects using Cartesian coordinates placed at specific points on the footprint outline, and to correlate them with physical variables. RESULTS: In the present study the young soccer players displayed a narrowing of the footprint due to a transversal variation on the isthmus, when compared to children of the same age who did not play soccer. These results suggest a physiological and biomechanical organization of the foot type in soccer due to the specific athletic tasks involved. CONCLUSION: As the foot type, in sport, is strictly associated to recurrent injuries, the result obtained in this study should be considered as indicative for future analysis. In fact, a clear and univocal knowledge of this phenomenon would be useful in the planning of a training protocol to reduce the incidence of sport related injuries.

Preliminary shape analysis of the outline of the baropodometric foot: patterns of covariation, allometry, sex and age differences, and loading variations.

AIM: Baropodometrical digital techniques map the pressures exerted on the foot plant during both static and dynamic loadings. The study of the distribution of such pressures makes it possible to evaluate the postural and locomotory biomechanics together with its pathological variations. This paper is aimed at evaluating the integration between baropodometric analysis (pressure distribution) and geometrical models (shape of the footprints), investigating the pattern of variation associated with normal plantar morphology. METHODS: The sample includes 91 individuals (47 males, 44 females), ranging from 5 to 85 years of age (mean and standard deviation = 40 + or - 24).The first component of variation is largely associated with the breadth of the isthmus, along a continuous gradient of increasing/decreasing flattening of the foot plant. This character being dominant upon the whole set of morphological components even in a non-pathological sample, such multivariate computation may represent a good diagnostic tool to quantify its degree of expression in individual subject or group samples. RESULTS: Sexual differences are not significant, and allometric variations associated with increasing plantar surface or stature are not quantitatively relevant. There are some differences between adult and young individuals, associated in the latter with a widening of the medial and posterior areas. CONCLUSIONS: These results provide a geometrical framework of baropodometrical analysis, suggesting possible future applications in diagnosis and basic research.

Endocranial traits. Prevalence and distribution in a recent human population

A recent human population from Italy was analysed for the prevalence and expression of endocranial characters, as well as for the presence of some ectocranial epigenetic traits. The purpose was to provide a supplementary database for the characterisation of some features used to compare the variability of extant and extinct human groups. Many differences between males and females are the result of allometric trajectories, with males shifted to a larger size. In contrast, other features may be unrelated to size and thus interpreted as real sexual characters. The cranial base angle is slightly but significantly related to size, particularly to the vertical skull development. The digital impressions are more expressed in males but there is no evidence of a correlation with size. Arachnoid granulations show no relationship with sex, age or size. The middle meningeal vessels are extremely variable but with a general dominance of the anterior branch providing the parietal supply, and with the left system slightly more developed than the right. The middle meningeal pattern is not related to the venous sinuses pattern. Some further aspects of the expression of these features are discussed, and data for the prevalence of epigenetic traits are reported (AU)

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Upgrade rate of core biopsy-determined atypical ductal hyperplasia by open excisional biopsy.

BACKGROUND: Core biopsy finding of atypical ductal hyperplasia (ADH) are generally followed by open biopsy to avoid underestimation of malignant disease. METHODS: Retrospective examination of 11 gauge stereotactic-guided vacuum-assisted core biopsies was made with respect to ADH diagnosis, follow-up open biopsy, and upgrade rate. Readily available clinical, mammographic, and pathologic features potentially contributory to an upgrade were studied. RESULTS: This series of 1,313 patients had 43 ADH diagnoses. Thirty-two had open follow-up. There were 4 upgrades. Mammographic indication for biopsy, age, removal of calcifications, and the percentage of ADH in the specimen were not significant in predicting an upgrade with all probabilities over 0.10, odds ratios not different than 1, and 95% bounds all encompassing 1. CONCLUSIONS: These data indicate a high upgrade rate (13%) for ADH-positive core biopsies with no definitive predictive criteria for an upgrade. Our data support follow-up excision of ADH lesions diagnosed by core biopsy.

Kinetics of CO and NO ligation with the Cys(331)-->Ala mutant of neuronal nitric-oxide synthase.

Nitric-oxide synthases (NOS) catalyze the conversion of l-arginine to NO, which then stimulates many physiological processes. In the active form, each NOS is a dimer; each strand has both a heme-binding oxygenase domain and a reductase domain. In neuronal NOS (nNOS), there is a conserved cysteine motif (CX(4)C) that participates in a ZnS(4) center, which stabilizes the dimer interface and/or the flavoprotein-heme domain interface. Previously, the Cys(331) --> Ala mutant was produced, and it proved to be inactive in catalysis and to have structural defects that disrupt the binding of l-Arg and tetrahydrobiopterin (BH(4)). Because binding l-Arg and BH(4) to wild type nNOS profoundly affects CO binding with little effect on NO binding, ligand binding to the mutant was characterized as follows. 1) The mutant initially has behavior different from native protein but reminiscent of isolated heme domain subchains. 2) Adding l-Arg and BH(4) has little effect immediately but substantial effect after extended incubation. 3) Incubation for 12 h restores behavior similar but not quite identical to that of wild type nNOS. Such incubation was shown previously to restore most but not all catalytic activity. These kinetic studies substantiate the hypothesis that zinc content is related to a structural rather than a catalytic role in maintaining active nNOS.

Kinetics of NO ligation with nitric-oxide synthase by flash photolysis and stopped-flow spectrophotometry.

Nitric-oxide synthase (NOS) catalyzes conversion of L-arginine to nitric oxide, which subsequently stimulates a host of physiological processes. Prior work suggests that NOS is inhibited by NO, providing opportunities for autoregulation. This contribution reports that NO reacts rapidly (ka congruent with 2 x 10(7) M-1 s-1) with neuronal NOS in both its ferric and ferrous oxidation states. Association kinetics are almost unaffected by L-arginine or the cofactor tetrahydrobiopterin. There is no evidence for the distinct two phases previously reported for association kinetics of CO. Small amounts of geminate recombination of NO trapped in a protein pocket can be observed over nanoseconds, and a much larger amount is inferred to take place at picosecond time scales. Dissociation rates are also very fast from the ferric form, in the neighborhood of 50 s-1, when measured by extrapolating association rates to the zero NO concentration limit. Scavenging experiments give dissociation rate constants more than an order of magnitude slower: still quite fast. For the ferrous species, extrapolation is not distinguishable from zero, while scavenging experiments give a dissociation rate constant near 10(-4) s-1. Implications of these results for interactions near the heme binding site are discussed.

Arterial blood pressure responses to cell-free hemoglobin solutions and the reaction with nitric oxide.

Changes in mean arterial pressure were monitored in rats following 50% isovolemic exchange transfusion with solutions of chemically modified hemoglobins. Blood pressure responses fall into three categories: 1) an immediate and sustained increase, 2) an immediate yet transient increase, or 3) no significant change either during or subsequent to exchange transfusion. The reactivities of these hemoglobins with nitric monoxide (.NO) were measured to test the hypothesis that different blood pressure responses to these solutions result from differences in .NO scavenging reactions. All hemoglobins studied exhibited a value of 30 microM-1 s-1 for both .NO bimolecular association rate constants and the rate constants for .NO-induced oxidation in vitro. Only the .NO dissociation rate constants and, thus, the equilibrium dissociation constants varied. Values of equilibrium dissociation constants ranged from 2 to 14 pM and varied inversely with vasopressor response. Hemoglobin solutions that exhibited either transient or no significant increase in blood pressure showed tighter .NO binding affinities than hemoglobin solutions that exhibited sustained increases. These results suggest that blood pressure increases observed upon exchange transfusion with cell-free hemoglobin solutions can not be the result of .NO scavenging reactions at the heme, but rather must be due to alternative physiologic mechanisms.

Sensitive visual test for concave diffraction gratings.

A simple visual test for the evaluation of concave diffraction gratings is described. It is twice as sensitive as the Foucault knife edge test, from which it is derived, and has the advantage that the images are straight and free of astigmatism. It is particularly useful for gratings with high ruling frequency where the above image faults limit the utility of the Foucault test. The test can be interpreted quantitatively and can detect zonal grating space errors of as little as 0.1 A.