Electric field effects on alanine tripeptide in sodium halide solutions.

The electric field effects on conformational properties of trialanine in different halide solutions were explored with long-scale molecular dynamics simulations. NaF, NaCl, NaBr and NaI solutions of low (0.2 M) and high (2 M) concentrations were exposed to a constant electric field of 1000 V/m. Generally, the electric field does not disturb trialanine's structure. Large structural changes appear only in the case of the supersaturated 2.0 M NaF solution containing NaF crystals. Although the electric field affects in a complex way, all the ions-water-peptide interactions, it predominantly affects the electroselectivity effect, which describes specific interactions such as the ion-pair formation.

The effect of calcium and vitamin D supplementation on osteoporotic rabbit bones studied by vibrational spectroscopy.

Fourier transform infrared spectroscopy is utilized to examine the effects of increased calcium, vitamin D, and combined calcium-vitamin D supplementation on osteoporotic rabbit bones with induced inflammation. The study includes different bone sites (femur, tibia, humerus, vertebral rib) in an effort to explore possible differences among the sites. We evaluate the following parameters: mineral-to-matrix ratio, carbonate content, and non-apatitic species (labile acid phosphate and labile carbonate) contribution to bone mineral. Results show that a relatively high dose of calcium or calcium with vitamin D supplementation increases the bone mineralization index significantly. On the other hand, vitamin D alone is not as effective in promoting mineralization even with high intake. Mature B-type apatite was detected for the group with calcium supplementation similar to that of aged bone. High vitamin D intake led to increased labile species concentration revealing bone formation. This is directly associated with the suppression of pro-inflammatory cytokines linked to induced inflammation. The latter is known to adversely alter bone metabolism, contributing to the aetiopathogenesis of osteoporosis. Thus, a high intake of vitamin D under inflammation-induced osteoporosis does not promote mineralization but suppresses bone resorption and restores metabolic balance.

Research and clinical applications of cancer genome sequencing.

PURPOSE OF REVIEW: To highlight the recent advances in cancer genome research and its clinical applications made possible by next-generation sequencing (NGS), with particular emphasis on gynecological and breast cancers is the purpose of the review. RECENT FINDINGS: Through advances in NGS technologies, whole-exome sequencing and whole-genome sequencing (WGS) have been performed on various cancers, identifying in the process numerous recurrent mutations and highly mutated genes. These cancers include uterine serous carcinomas, high-grade serous ovarian adenocarcinomas and breast cancer. In contrast to identifying somatic mutations in sporadic cancers, a far smaller number of studies using NGS have been conducted to identify new causal mutations or genes for hereditary cancer syndromes. In addition to research discovery, diagnostic applications of NGS have also become increasingly evident. Thus, WGS has been applied in a diagnostic context to identify a complex chromosomal rearrangement in a patient with acute myeloid leukemia of unclear subtype. Similarly, the targeted sequencing of panels of known cancer genes using NGS has demonstrated its robustness in the context of identifying known pathological mutations. SUMMARY: The research and clinical applications of cancer genome sequencing have progressed at an unprecedented pace over the last few years, and this promises to be accelerated with new developments of high-throughput NGS technologies and robust analytical tools.

Gray Hausdorff distance measure for medical image comparison in dermatology: Evaluation of treatment effectiveness by image similarity.

INTRODUCTION: In clinical dermatology, the stabilization of the overall skin condition can be in many cases the earliest qualitative measure of the effectiveness of the therapeutic intervention. Subjective image comparisons, that offer empirical 'qualitative' judgments of degrees of image similarities, are traditionally employed by the involved physicians. OBJECTIVES: To quantify, by means of an image similarity metric, the degree of stabilization of an expanding skin disease, and to identify the situation of 'no further change' of the skin condition of the patient, providing thus the physician with an early, objective measure of the efficacy of the used therapy. METHODS: For treatment assessment, a variant of gray Hausdorff distance metric was employed to compare images of lesional skin segments of a patient, taken at different time points during a therapeutic course. Prior to image comparison, an effective preprocessing scheme was adapted to constrain wide pose and light variations. The proposed similarity algorithm was tested on raw clinical image data sets of patients diagnosed with toxic epidermal necrolysis, a life-threatening condition with rapid evolution. Fine tuning of algorithm's parameters was optimized using Precision-Recall curves. RESULTS: Proposed image comparison method resulted in a high-degree of image similarity (about 96%) between pictures taken at second and fifth day of hospitalization. Current similarity results substantiate a significant agreement between the computer-treatment assessment, by means of image comparison, and the corresponding clinical experts' review of skin condition. CONCLUSION: Objective evidence of 'no further change' situation may provide (a) intuitive clinical decision support to dermatologists in assessing aggressive skin conditions, where the timely evaluation of treatment response is of vital importance and (b) a versatile end-point measure for corresponding therapeutic clinical trials.

Treatment of toxic epidermal necrolysis with the combination of infliximab and high-dose intravenous immunoglobulin.

BACKGROUND: Therapeutic evidence for toxic epidermal necrolysis (TEN) is indicative for high-dose intravenous immunoglobulin yet inconclusive for corticosteroids. OBJECTIVE: To describe the combination of corticosteroids, infliximab and a high-dose intravenous immunoglobulin course for TEN. PATIENTS AND METHODS: In three patients (SCORTEN survival probabilities: 41.7%, 64.2%, 41.7%) disease control was evaluated by (a) employing quantitative image analysis to measure progression of skin detachment and (b) patients' outcome (complete re-epithelization). Published cases of TEN treatments with infliximab were retrieved from PubMed. RESULTS: Within 48 h skin disease progression was arrested in all patients. Two patients were discharged after 3 weeks without any sequels from skin or conjunctivae. One patient passed away on the ninth day, however with noticeably improved skin (mortality rate: 33% observed vs. 50% expected). A PubMed search retrieved five TEN patients treated successfully with infliximab. CONCLUSION: The described combination presents a feasible therapeutic alternative for TEN that warrants further evaluation.

Infrared spectroscopic assessment of the inflammation-mediated osteoporosis (IMO) model applied to rabbit bone.

A model of osteoporosis based on induced inflammation (IMO) was applied on rabbit bones. The structural heterogeneity and molecular complexity of bone significantly affect bone mechanical properties. A tool like Fourier transform infrared spectroscopy, able to analyze both the inorganic and organic phase simultaneously, could provide compositional information regarding cortical and trabecular sections under normal and osteoporotic conditions. In this study, we assessed the mineral/matrix ratio, carbonate and phosphate content and labile (i.e., non-apatitic) species contribution to bone mineral and collagen cross-linking patterns. Clear differences were observed between cortical and trabecular bone regarding mineral and carbonate content. Induced inflammation lowers the mineral/matrix ratio and increases the overall carbonate accumulation. Elevated concentrations of labile species were detected in osteoporotic samples, especially in the trabecular sections. Collagen cross-linking patterns were indirectly observed through the 1660/1690 cm⁻¹ ratio in the amide I band and a positive correlation was found with the mineralization index. Principal component analysis (PCA) applied to female samples successfully clustered trabecular and osteoporotic cases. The important role played by the phosphate ions was confirmed by corresponding loadings plots. The results suggest that the application of the IMO model to rabbit bones effectively alters bone remodeling and forms an osteoporotic bone matrix with a dissimilar composition compared to the normal one.

Eye safety related to near infrared radiation exposure to biometric devices.

Biometrics has become an emerging field of technology due to its intrinsic security features concerning the identification of individuals by means of measurable biological characteristics. Two of the most promising biometric modalities are iris and retina recognition, which primarily use nonionizing radiation in the infrared region. Illumination of the eye is achieved by infrared light emitting diodes (LEDs). Even if few LED sources are capable of causing direct eye damage as they emit incoherent light, there is a growing concern about the possible use of LED arrays that might pose a potential threat. Exposure to intense coherent infrared radiation has been proven to have significant effects on living tissues. The purpose of this study is to explore the biological effects arising from exposing the eye to near infrared radiation with reference to international legislation.

Spectroscopic assessment of normal cortical bone: differences in relation to bone site and sex.

Bone is a highly complex, composite tissue and its properties normally vary with age, type, and disorders. Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy techniques were used to study the effect of bone sites and sex to mineral and matrix content and composition. The results show that in rats, all inorganic phases consist of poorly crystalline B-type carbonated apatite, while overall mineralization and carbonate content is virtually unaffected among samples. Statistically significant differences were detected for the nonapatitic environments of acid phosphate and carbonate content. The mean values for the Ca/P ratio point to an increasing trend from tibia to forearm, and to femoral sections.

Collagen fibril diameter in relation to bone site and to calcium/phosphorus ratio.

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of female and male rats and rabbits using electron microscopy analysis. In most cases, statistically significant differences in mean fibril diameter values between different bone sites were detected. The order of magnitude for the above structural parameter was the same for both genders in both experimental species. In rats, the greatest mean diameter value was that for the femoral, while in rabbits, the one for the rear tibia demonstrating a dependence on bone use and life style. An important aspect was the agreement between these observations and the mean values for Ca/P ratio, as observed in previous experiments, in the same bone sites and animals. Collagen fibril diameter and Ca/P ratio can both serve as indexes of bone quality.

The role of collagen in bone structure: an image processing approach.

Bone collagen structure in normal and pathological tissues is illustrated using techniques of thin section transmission electron microscopy and computer-assisted analysis. The normal bone collagen types, fibril architecture and diameter are described. In pathological tissue, deviations from normal fine structure are reflected in abnormal arrangements of collagen fibrils and abnormalities in fibril diameter. Computer analyses of normal fibril positive staining patterns are presented in order to provide a basis for comparing such patterns with pathological ones.

Collagen fibril diameter in relation to bone site. a quantitative ultrastructural study.

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of rats using electron microscopy analysis. Statistically significant differences (0.001

Bone calcium, phosphorus detection by Auger electron spectroscopy.

Auger electron spectroscopy was used to detect calcium and phosphorus of cortical bone from rat femoral neck and rear tibia. Spectra were taken from bone pieces as well as from disks prepared from grinded bone material. Experimental conditions were found whereby the samples could be analyzed without conductive coatings. The results of this preliminary investigation demonstrate that Auger electron spectroscopy can be used to study bone mineral elements.

Evaluation of vermillion border descriptors and relevance vector machines discrimination model for making probabilistic predictions of solar cheilosis on digital lip photographs.

INTRODUCTION: Solar cheilosis (SC), a common precancer of the lower lip with a high potential to progress to invasive squamous cell carcinoma, presents with characteristic morphological vermillion-skin border alterations, like the border retraction. AIM: To determine robust macro-morphological descriptors of the vermillion border from non-standardized digital photographs and to exploit a probabilistic model for SC recognition in real clinical environments. METHODS: Lip borders of 150 individuals (75 SC patients, 75 non-SC controls) were quantified on the basis of the extent of vermillion retraction and the degree of border irregularity employing fractal features and type-P Fourier descriptors. Eight lip border quantifiers were evaluated in terms of their reliability and reproducibility. The probabilistic 'diagnostic' model was implemented using the relevance vector machine (RVM) algorithm. RESULTS: Picture acquisition contributes substantially to overall variability of lip border images; however, for the different lip descriptors 33% to 65% of border morphological variability is due to differences among individuals. Different camera operators or the use of cameras with different specifications did not affect significantly the extracted lip features. The proposed RVM probabilistic model yielded a high sensitivity and specificity of 94.6% and 96%, respectively. CONCLUSION: We explored the use of digital photography within the clinical routine setting to validate a probabilistic model for the assessment of lip conditions like SC. The proposed method opens new perspectives toward a cost effective, non-invasive monitoring of SC to support large scale epidemiological and interventional studies in different clinical environments.

Aged skin: detection of alterations of major collagen types ratio by image processing of electron-optical data.

Automated algorithms are developed in this paper based on digital signal processing to correlate electron-optical data from skin collagen fibrils with known sequence data. In particular, they detect alterations on the ratio of major collagen types in skin upon age.

Calcium, phosphorus, calcium-phosphorus ratio in rib bone of healthy humans.

Calcium and phosphorus concentrations as well as the Ca/P ratio were estimated in intact rib bone samples from healthy humans, 37 women and 45 men, aged 15-55 yr. For Ca and P concentration measurements, instrumental neutron activation analysis was used. The mean values (mean +/- SD) for the investigated parameters were 19.3 +/- 4.5% of dry bone weight, 8.42 +/- 2.14% of dry bone weight, and a ratio of 2.33 +/- 0.34, respectively. Statistically significant differences for the above parameters were not observed to be related either to age or sex. The mean values for Ca, P, and the Ca/P ratio were within a very wide range of published data and close to their medians. The individual variation for the Ca/P ratio in rib bone from healthy humans was lower than those for Ca and P taken separately. An indication is that the specificity of the Ca/P ratio improves upon that for Ca and P concentrations and may be more reliable in the diagnosis of bone disorders.

Collagenous tissues upon lithium treatment: a quantitative ultrastructural study.

In this review, the influence of lithium treatment in mouse, rat, and rabbit skin, liver, bone, and aorta, as well as arachnoid and dura mater collagen fibrils, is examined using electron microscopy and image processing. Structural changes (fibril architecture and diameter) are detected at the ultrastructural level in specimens from all lithium-treated tissues. The overall collagen fibril architecture is disturbed as compared with specimens from normal species. The mean diameter values of treated collagen fibrils are significantly smaller than those from controls in all tissues examined. The banding patterns of fibrils are normal in all cases. Measurements by a computerized method of measuring axial periodicity of fibrils indicate no effect of lithium on this parameter. Computer analysis shows no differences in charged amino acid composition between lithium-treated and -untreated samples. Under the present experimental conditions, lithium can induce permanent structural collagen alterations.

The effects of 910-MHz electromagnetic field on rat cranial arachnoid and dura mater collagen. The axial periodicity of collagen fibrils.

The axial periodicity of rat arachnoid and dura mater collagen fibrils exposed to 910 MHz for 2 h/day for 30 consecutive days was measured by means of image analysis of electron-optical data. Such measurements were compared with those from sham-exposed animals. These measurements reveal that on exposure, the intermolecular interactions during collagen fibril assembly are affected.