Determination of volume, shape and refractive index of individual blood platelets

Light scattering patterns (LSP) of blood platelets were theoretically and experimentally analyzed. We used spicular spheroids as a model for the platelets with pseudopodia. The discrete dipole approximation was employed to simulate light scattering from an individual spicular spheroid constructed from a homogeneous oblate spheroid and 14 rectilinear parallelepipeds rising from the cell centre. These parallelepipeds have a weak effect on the LSP over the measured angular range. Therefore, a homogeneous oblate spheroid was taken as a simplified optical model for platelets. Using the T-matrix method, we computed the LSP over a range of volumes, aspect ratios and refractive indices. Measured LSPs of individual platelets were compared one by one with the theoretical set and the best fit was taken to characterize the measured platelets, resulting in distributions of volume, aspect ratio and refractive index.Comment: 10 pages, 6 figure

СОВРЕМЕННЫЕ ТЕХНОЛОГИИ В ХИРУРГИЧЕСКОМ ЛЕЧЕНИИ ПОСЛЕДСТВИЙ ТРАВМЫ ЧЕРЕПА И ГОЛОВНОГО МОЗГА

The paper presents main types of surgically relevant posttraumatic lesions in 4136 patients with skull vault as well as skull base defects, craniofacial deformities, recurrent CSF leaks, arterio-venous fistulas, aneurysms and pseudoaneurysms etc. Classification of TBI sequelae and complications as well as its clinical course grading is presented. The use of modern neuroimaging techniques for studying pathophysiologic mechanisms and complications of TBI has been demonstrated. Special emphasis was given to minimally invasive and reconstructive surgery; computer modeling with subsequent full-copy stereolitographic laser implant setup was shown which is of great importance in cases of large and complex skull base and craniofacial deformities. Patient selection for transcranial and endonasal CSF leak closure techniques was justified. Treatment of post-traumatic vascular injuries using Serbinenko balloon-catheters as well as modern techniques such as stents, coils and embolization has been demonstrated.  В сообщении (созданном по материалам доклада, представленного на Сессии общего собрания РАМН, Санкт-Петербург, 14−15 июня 2012 г.) представлены основные хирургически значимые формы посттравматической патологии у 4136 пациентов с дефектами и деформациями костей свода, основания черепа и лицевого скелета, рецидивирующей ликвореей, артериосинусными соустьями, истинными и ложными аневризмами и др. Разработана классификация последствий и осложнений черепно-мозговой травмы, а также периодизация ее клинического течения. Раскрыты возможности современных нейровизуализационных технологий распознавания и исследования патогенеза последствий и осложнений черепно-мозговой травмы. Особое внимание уделено реконструктивной и минимально инвазивной хирургии, детально описан метод компьютерного моделирования и последующего стереолитографического лазерного воспроизведения полномасштабных копий черепа, его дефектов и имплантатов,  что особенно значимо при обширных и сложных краниобазальных и краниофациальных повреждениях. Обосновано дифференцированное применение интракраниальных и эндоназальных доступов для закрытия хронических ликворных фистул. Вместе с впервые созданной в НИИ нейрохирургии им. Н.Н. Бурденко методикой эндоваскулярной реконструкции магистральных сосудов с помощью баллонов-катетеров Ф.А. Сербиненко представлены новые подходы, опирающиеся на современные технологии с использованием стентов, микроспиралей и эмболизирующих композиций.

PECULIARITIES OF THE FIBROSIS AND CIRRHOSIS MONITORING AMONG CHILDREN WITH CHRONIC LIVER DISEASES

The researchers examined the opportunities to use determination in the serum among children with chronic liver diseases of various etiologies of the hyaluronic acid levels, collagen type IV, matrix metalloproteinase-2, tissue inhibitor of the matrix proteinases 1 in diagnostics of the liver fibrosis degree. They have found out that children with the given pathology show significantly growing concentrations of these compounds against marked fibrotic changes in the liver parenchyma. Hyaluronic acid, collagen type IV and matrix metalloproteinase 2 may be reliable noninvasive cirrhosis markers and used to monitor the efficiency of therapy for the chronic liver diseases among children.Key words: matrix metalloproteinase-2, tissular inhibitor of the matrix proteinases 1, liver cirrhosis, markers, diagnostics, children

PECULIARITIES OF THE FIBROSIS AND CIRRHOSIS MONITORING AMONG CHILDREN WITH CHRONIC LIVER DISEASES

The researchers examined the opportunities to use determination in the serum among children with chronic liver diseases of various etiologies of the hyaluronic acid levels, collagen type IV, matrix metalloproteinase-2, tissue inhibitor of the matrix proteinases 1 in diagnostics of the liver fibrosis degree. They have found out that children with the given pathology show significantly growing concentrations of these compounds against marked fibrotic changes in the liver parenchyma. Hyaluronic acid, collagen type IV and matrix metalloproteinase 2 may be reliable noninvasive cirrhosis markers and used to monitor the efficiency of therapy for the chronic liver diseases among children.Key words: matrix metalloproteinase-2, tissular inhibitor of the matrix proteinases 1, liver cirrhosis, markers, diagnostics, children

FAECAL CALPROTECTIN IN NONINVASIVE DIAGNOSTICS OF THE INFLAMMATORY ENTERIC DISEASES AMONG CHILDREN

The authors studied the opportunities to define the level of faecal calprotectin in diagnostics of the inflammatory enteric diseases (grohn's disease and colitis gravis) among children. It was established that children, suffering from the inflammatory enteric diseases, the concentration of faecal calprotectin increases, thus, correlating with the clinical and endoscopic activity of the disease, as well as with the spread of the intestinal impairment. Faecal calprotectin may be a reliable marker of the inflammation activity in the event of grohn's disease and colitis gravis.Key words: faecal calprotectin, inflammatory enteric diseases, colitis gravis, grohn's disease, diagnostics, children