Гипомеланоз Ито: описание клинического случая

This work is devoted to a literature review and description of a clinical case of Hypomelanosis of Ito. Considering the rare frequency of the disease, not much literature data has been accumulated to date. The description of the disease can be interesting for a number of reasons. Hypomelanosis of Ito is a congenital variant of phacomatosis affecting the skin and nervous system. The disease appears sporadic. The majority of cases are diagnosed clinically, which is due to the lack of a precisely established molecular defect and, as a result, the «difficulties» of molecular diagnostic. This is evidenced by the absence of standard genetic analysis. Cytogenetic and molecular genetic diagnostic methods often do not establish a «causal» mutation. This description of the clinical case of the disease is dedicated to the child who was observed in the Department of Pediatric Neurology of Saint-Petersburg State Pediatric Medical University. The patient was diagnosed clinically in early childhood; the leading symptoms of the disease were delayed speech development and epileptic seizures. No family history of neurocutaneous disorders was noted.Given the different approaches to the genetic verification of the syndrome, some methods of cytogenetic diagnostics were performed at the department, as the most frequently prescribed study to date. According to the results of the studies, no damage was found. Given the fact that genetic verification itself does not affect the prognosis and management of patients, it was decided not to continue molecular diagnostics.Данная работа посвящена литературному обзору и описанию клинического случая гипомеланоза Ито. Учитывая редкую частоту встречаемости болезни, литературных данных на сегодняшний день накоплено не много. Описание заболевания может быть интересным по ряду причин. Гипомеланоз Ито является врожденным вариантом факоматоза, поражающим кожу и нервную систему. Заболевание носит спорадический характер. Диагноз большинства случаев выставляется клинически, что связано с отсутствием точно установленного молекулярного дефекта и, как следствие, «сложностями» в генетической диагностике. Этому свидетельствует отсутствие стандартного генетического анализа. Цитогенетические и молекулярно-генетические методы диагностики зачастую не устанавливают «причинную» мутацию.Данное описание клинического случая болезни посвящено ребенку, наблюдавшемуся в отделении детской неврологии СПбГПМУ. Диагноз пациенту был установлен в раннем детском возрасте в соответствии с клиническими критериями, ведущими симптомами болезни были задержка психоречевого развития и эпилептические приступы. Семейный анамнез по нейрокожной патологии не отягощен. Учитывая разные подходы к генетической верификации синдрома, на отделении была проведена цитогенетическая диагностика как наиболее часто назначаемое исследование на сегодняшний день. По результатам исследований повреждений обнаружено не было. Учитывая тот факт, что сама по себе генетическая верификация не влияет на прогноз и тактику ведения больных, было принято решение не продолжать молекулярную диагностику. В настоящей работе описана тактика диагностики, лечения пациента, а также результаты медико-генетического консультирования семьи

Microsecond dynamics control the HIV-1 Envelope conformation

The HIV-1 Envelope (Env) glycoprotein facilitates host cell fusion through a complex series of receptor-induced structural changes. Although remarkable progress has been made in understanding the structures of various Env conformations, microsecond timescale dynamics have not been studied experimentally. Here, we used time-resolved, temperature-jump small-angle x-ray scattering to monitor structural rearrangements in an HIV-1 Env SOSIP ectodomain construct with microsecond precision. In two distinct Env variants, we detected a transition that correlated with known Env structure rearrangements with a time constant in the hundreds of microseconds range. A previously unknown structural transition was also observed, which occurred with a time constant below 10 μs, and involved an order-to-disorder transition in the trimer apex. Using this information, we engineered an Env SOSIP construct that locks the trimer in the prefusion closed state by connecting adjacent protomers via disulfides. Our findings show that the microsecond timescale structural dynamics play an essential role in controlling the Env conformation with impacts on vaccine design

DEVELOPMENT OF BIOENGINEERING DESIGN OF ARTIFICIAL CORNEA BASED ON TISSUE MATRIX MADE OF SPIDROIN AND CULTIVATED CELLS OF EYE LIMBUS ZONE

Purpose. To study prerequisites for a development of artificial cornea bioengineered design based on recombinant spidroin tissue matrix by behavior evaluation of 2D (planar) and 3D cell (threedimensional) cultures on its surface.Material and methods. We studied epithelioid and stromal primary cell cultures (MSC-L) received from the limbal zone of post-mortem donor eyes. Cells were seeded on Petri dishes and on cavities of cultural trays (Corning, USA). To get spheroid structures the cells after the second passage underwent the centrifuge and were seeded on agarous trays then were cultivated in thermostatic chamber (Cell-IQ, Chip Man Technologies, Finland) under standard conditions (37° C, 5% CO2). Control over cell growth and morphology in trays was conducted under inverted microscope CKX41 (Olympus, Japan). To count the cell quantity and their viability the automatic cell counter Countess (Invitrogen, USA) was used, to analyze the surface proteins expression the flow cytofluorimetry was applied. For matrices colonization we used the 3rd passage MSC-L and 7-day spheroids of MSC-L origin. To evaluate 2D and 3D cell cultures growth on the surface of membranous matrices of recombinant spidroin, to estimate its non-toxicity and adhesiveness the immunohistochemistry, light time-lapse microscopy (Cell-IQ, Chip Man Technologies, Finland), laser scanning confocal microscopy (FluoView FV10i, Olympus, Japan) and raster electronic microscopy (CamScan, Japan) were incorporated.Results. Few hours after cell seeding there was active cells’ attachment to the substrate. Attached cells were characterized by rounded, oval or polygonal ordonnance. 24 hours later bipolar elongated cells and islets of migrating epithelioid cells appearance were observed. In the incubation process under gravity force the spheroids were accumulated predominantly in the central zone of the matrix, 2 hours later an active migration of spheroids surface zone epithelioid cells was registered on the membrane. After 24 hours of incubation all seeded on the surface of membranous matrix cells possessed a mesenchyme-like phenotype. Spheroids had an ability to merge limitlessly, later we observed a new microtissue formation with epithelioid cells on the surface and mesenchyme-like cells in the central area. Both solitary spheroids and merger-derived microtissue contained epithelial and mesenchymal components as well as regularly organized fibrils of extracellular matrix.Conclusions. According to aforementioned data the development of artificial cornea bioengineered cell-tissue constructions based on the technology of 3D cell spheroids cultivation derived from multipotent stem cells of the limbus and spidroin matrix presents a promising prospect requiring a further profound investigation

Direct Observation of Cooperative Protein Structural Dynamics of Homodimeric Hemoglobin from 100 ps to 10 ms with Pump–Probe X-ray Solution Scattering

Proteins serve as molecular machines in performing their biological functions, but the detailed structural transitions are difficult to observe in their native aqueous environments in real time. For example, despite extensive studies, the solution-phase structures of the intermediates along the allosteric pathways for the transitions between the relaxed (R) and tense (T) forms have been elusive. In this work, we employed picosecond X-ray solution scattering and novel structural analysis to track the details of the structural dynamics of wild-type homodimeric hemoglobin (HbI) from the clam Scapharca inaequivalvis and its F97Y mutant over a wide time range from 100 ps to 56.2 ms. From kinetic analysis of the measured time-resolved X-ray solution scattering data, we identified three structurally distinct intermediates (I-1, I-2, and I-3) and their kinetic pathways common for both the wild type and the mutant. The data revealed that the singly liganded and unliganded forms of each intermediate share the same structure, providing direct evidence that the ligand photolysis of only a single subunit induces the same structural change as the complete photolysis of both subunits does. In addition, by applying novel structural analysis to the scattering data, we elucidated the detailed structural changes in the protein, including changes in the heme heme distance, the quaternary rotation angle of subunits, and interfacial water gain/loss. The earliest, R-like I-1 intermediate is generated within 100 ps and transforms to the R-like I-2 intermediate with a time constant of 3.2 +/- 0.2 ns. Subsequently, the late, T-like I-3 intermediate is formed via subunit rotation, a decrease in the heme-heme distance, and substantial gain of interfacial water and exhibits ligation-dependent formation kinetics with time constants of 730 +/- 120 ns for the fully photolyzed form and 5.6 +/- 0.8 mu s for the partially photolyzed form. For the mutant, the overall kinetics are accelerated, and the formation of the T-like I-3 intermediate involves interfacial water loss (instead of water entry) and lacks the contraction of the heme-heme distance, thus underscoring the dramatic effect of the F97Y mutation. The ability to keep track of the detailed movements of the protein in aqueous solution in real time provides new insights into the protein structural dynamics.1149sciescopu

Data Anonymization that Leads to the Most Accurate Estimates of Statistical Characteristics: Fuzzy-Motivated Approach

Abstract—To preserve privacy, the original data points (with exact values) are replaced by boxes containing each (inaccessible) data point. This privacy-motivated uncertainty leads to uncertainty in the statistical characteristics computed based on this data. In a previous paper, we described how to minimize this uncertainty under the assumption that we use the same standard statistical estimates for the desired characteristics. In this paper, we show that we can further decrease the resulting uncertainty if we allow fuzzy-motivated weighted estimates, and we explain how to optimally select the corresponding weights. I. FORMULATION OF THE PROBLEM Need to preserve privacy. In many practical applications, e.g., in medicine and in education, to better serve customers, it is important to know as much as possible about the potential customers. Customers are often reluctant to share information

Mineral bone density comparative assessment in patients with systemic lupus erythematosus treated and not treated with glucocorticoids

Objective. To compare bone mineral density (BMD) in pts with systemic lupus erythematosus (SLE), treated and untreated by glucocorticoids (GC). Matherial and Methods. 30 females with reliable SLE were examined (APA, 1982), 15 had GC (prednisolone 7.5-60mg/day, median cumulative dose 10.7±6.6g) (1st group), 15 others did not take GC (2nd group). Groups were comparable by age, SLE course duration, body weight. All were females with normal menses period. BMD was assessed in low back vertebral region and femoral neck in standard projections on dichromatic X-ray densitometer QDR-1000 Plus (Hologic, USA) in absolute values (g/cm2) and T-index. Results. BMD in low back was statistically reliably lower in the 1st group as compared with the 2nd (0,918±0,118 and 1,036±0,156; p=0,027). In the left femoral neck there were no differences in mineralization of bone tissue (0,769±0,167 and 0,807±0,227; p=0,568), BMD decreasing in the studied bone region reliably prevailed among pts of the 1st group (n=ll) as compared with the 2nd (n=2) (p=0.003). Conclusion. SLE pis treated by GC demonstrated reliably lower indices of BMD in LI-L4 as compared with pts who were not treated by GC

Real-time tracking of protein unfolding with time-resolved x-ray solution scattering

The correct folding of proteins is of paramount importance for their function, and protein misfolding is believed to be the primary cause of a wide range of diseases. Protein folding has been investigated with time-averaged methods and time-resolved spectroscopy, but observing the structural dynamics of the unfolding process in real-time is challenging. Here, we demonstrate an approach to directly reveal the structural changes in the unfolding reaction. We use nano- to millisecond time-resolved x-ray solution scattering to probe the unfolding of apomyoglobin. The unfolding reaction was triggered using a temperature jump, which was induced by a nanosecond laser pulse. We demonstrate a new strategy to interpret time-resolved x-ray solution scattering data, which evaluates ensembles of structures obtained from molecular dynamics simulations. We find that apomyoglobin passes three states when unfolding, which we characterize as native, molten globule, and unfolded. The molten globule dominates the population under the conditions investigated herein, whereas native and unfolded structures primarily contribute before the laser jump and 30 μs after it, respectively. The molten globule retains much of the native structure but shows a dynamic pattern of inter-residue contacts. Our study demonstrates a new strategy to directly observe structural changes over the cause of the unfolding reaction, providing time- and spatially resolved atomic details of the folding mechanism of globular proteins