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1.
Article in English, Russian | MEDLINE | ID: mdl-36534622

ABSTRACT

Gliomas are the most common neuroepithelial brain tumors. The modern classification of tumors of central nervous system and treatment approaches are based on tissue and molecular features of a particular neoplasm. Today, histological and molecular genetic typing of tumors can only be carried out through invasive procedures. In this regard, non-invasive preoperative diagnosis in neurooncology is appreclated. One of the perspective areas is artificial intelligence applied for neuroimaging to identify significant patterns associated with histological and molecular profiles of tumors and not obvlous for a specialist. OBJECTIVE: To evaluate diagnostic accuracy of deep learning methods for glioma typing according to the 2007 WHO classification based on preoperative magnetic resonance imaging (MRI) data. MATERIAL AND METHODS: The study included MR scans of patients with glial tumors undergoing neurosurgical treatment at the Burdenko National Medical Research Center for Neurosurgery. All patients underwent preoperative contrast-enhanced MRI. 2D and 3D MR scans were used for learning of artificial neural networks with two architectures (Resnest200e and DenseNet, respectively) in classifying tumors into 4 categories (WHO grades I-IV). Learning was provided on 80% of random examinations. Classification quality metrics were evaluated in other 20% of examinations (validation and test samples). RESULTS: Analysis included 707 contrast-enhanced T1 welghted images. 3D classification based on DenseNet model showed the best result in predicting WHO tumor grade (accuracy 83%, AUC 0.95). Other authors reported similar results for other methods. CONCLUSION: The first results of our study confirmed the fundamental possibility of grading axial contrast-enhanced T1 images according to the 2007 WHO classes using deep learning models.


Subject(s)
Brain Neoplasms , Glioma , Humans , Artificial Intelligence , Glioma/surgery , Magnetic Resonance Imaging/methods , Brain Neoplasms/pathology , Machine Learning , Brain/pathology , Neoplasm Grading
2.
Urologiia ; (3): 18-23, 2013.
Article in Russian | MEDLINE | ID: mdl-23987043

ABSTRACT

The aim of the study was to identify the effects of virilizing and feminizing hormone replacement therapy on the morphology and function of the male and female reproductive systems in the application of technology for change of sex. The results of the pathomorphorogic examination of the uterus with appendages, testes, the corpora cavernosa, and biopsies of the prostate and mammary glands at different times of treatment in transsexual patients aged from 22 to 43 years are presented. It was found that prolonged exposure to high concentrations of exogenous hormones in the women and men significantly increases the risk of tumors and tumor-like processes, such as endocervicosis, cervical intraepithelial neoplasia, metaplasia of the endometrium, endocervical and endometrial polyps, endometrial hyperplasia, proliferative processes in tubular epithelium, ovarian polycystic disease, mammary tumors, hyperplasia and metaplasia of the ductal epithelium of the prostate gland.


Subject(s)
Breast/pathology , Endometrium/pathology , Prostate/pathology , Sex Reassignment Procedures , Testis/pathology , Transgender Persons , Adult , Breast/physiopathology , Endometrium/physiopathology , Female , Humans , Male , Prostate/physiopathology , Testis/physiopathology
3.
Phys Rev Lett ; 109(13): 137801, 2012 Sep 28.
Article in English | MEDLINE | ID: mdl-23030120

ABSTRACT

Deactivation of excited phenanthrene by molecular oxygen is utilized to probe the structural heterogeneity of supercooled propylene carbonate. The diffusion rate of oxygen molecules in different regions varies over two orders of magnitude. The size of the regions of different oxygen mobility was determined to be 1.5 nm. Values from 0.2 to 30 s have been obtained for the lifetime of these regions over a temperature range from T(g)-1 to T(g)+4 K (T(g)=158 K). The heterogeneity lifetime is in close agreement with the α-relaxation time determined by dielectric spectroscopy. The obtained results argue in favor of the statement that the heterogeneous cooperative dynamics of host molecules (so-called dynamical heterogeneity) is of structural origin.

4.
Urologiia ; (6): 9-12, 2011.
Article in Russian | MEDLINE | ID: mdl-22448472

ABSTRACT

The article presents the results of vaginoplasty in male-to-female sex reassignment surgery, technique of this operation, complications, long-term consequences, functional and social changes.


Subject(s)
Sex Reassignment Surgery/methods , Adolescent , Adult , Dermatologic Surgical Procedures , Female , Humans , Male , Middle Aged , Penis/surgery , Surgery, Plastic/methods
5.
J Chem Phys ; 133(7): 074501, 2010 Aug 21.
Article in English | MEDLINE | ID: mdl-20726646

ABSTRACT

A new method using the quenching of guest molecule phosphorescence by molecular oxygen is proposed for determination of heterogeneity size in glassy matrixes. The method is based on the high sensitivity of the diffusion of oxygen molecules to spatial density fluctuations. Phenanthrene phosphorescence decay was monitored at different concentrations of molecular oxygen in propylene carbonate below T(g). An unusual dependence of the phosphorescence decay on oxygen concentration was observed: an increase in the concentration leads to anomalously large increase in the quenching rate at short times. This dependence is considered to be caused by matrix heterogeneity. To describe the phosphorescence decay, we use a model of glass as a heterogeneous medium where oxygen jump rates are spatially correlated. The length of spatial correlation for the jump rates is taken as heterogeneity size. Using the model, the value of 1.5+/-0.5 nm was obtained for the size of structural heterogeneities in glassy propylene carbonate. The dispersion of barriers for oxygen jumps is estimated to be 4+/-1 kJ/mole and the average barrier energy is found to be 50 kJ/mole.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 56(13): 2501-7, 2000 Nov 15.
Article in English | MEDLINE | ID: mdl-11132133

ABSTRACT

The methods have been developed for studying oxygen mobility by donor quenching in solutions with uniform concentration and in geminate pairs in a solid phase. It is shown that the kinetics of luminescence variations with time is described by a diffusion model. Oxygen mobility has been studied at low temperatures (77 K) in hard polymer matrices. squalane. glasses of low-molecular hydrocarbons and alcohols. The methods can be used to measure very low oxygen mobility with a diffusion coefficient of about 10(-23) cm2 s(-1).


Subject(s)
Oxygen/chemistry , Diffusion , Fluorescence , Glass , Luminescence , Polymers , Solutions , Time Factors
9.
Sud Med Ekspert ; 41(5): 20-43, 1998.
Article in Russian | MEDLINE | ID: mdl-9819994

ABSTRACT

Results of medical anthropological expert studies of bone remains of Emperor Nicholas II, his family members, and persons in their attendance are presented. Craniological (including computer photoblending), odontological, osteometric, and spectral methods were sued. Numerous photographs, Imperial Family clothes from museums, soil specimens from Tsarskoe Selo and place of burial were used. Expert studies confirmed previous conclusions on personal identification of skeletons as Nicholas II and four Imperial Family members. Additional proofs of identification of skeleton No. 6 as Great Princess Anastasia Nikolaevna are presented. No remains which could be identified as Cesarevich Alexei Nikolaevich and Great Princess Maria Nikolaevna were found. The so-called "adolescent teeth" are upper teeth of a subject aged 17-18. Rare odontoglyphic characteristics of these teeth permit referring them only to skull No. 6 (Great Princess Anastasia Nikolaevna) but not to an adolescent, specifically, to Cesarevich Alexei Nikolaevich.


Subject(s)
Bone and Bones/pathology , Famous Persons , Forensic Anthropology/methods , Burial , Cephalometry/methods , Clothing , Female , Forensic Dentistry/methods , History, 20th Century , Humans , Male , Racial Groups , Russia (Pre-1917) , Sex Determination Analysis/methods
11.
Neurochem Int ; 31(2): 161-7, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9220448

ABSTRACT

The survival and proper functioning of sympathetic neurons are dependent on nerve growth factor (NGF). When immature sympathetic neurons are deprived of NGF, they undergo an 'active' dying process usually termed 'programmed cell death' or 'apoptosis'. This trophic factor dependence is age-related such that the cells become less dependent on NGF as they mature. Removal of NGF in immature cultures, which triggered the process of programmed cell death, resulted in a significant decrease of intracellular cAMP levels. In contrast, when these cells matured in culture and became relatively NGF independent, NGF withdrawal did not lead to a drop of cAMP levels. Pituitary adenylate cyclase-activating polypeptide (PACAP), a naturally occurring bioactive peptide structurally similar to VIP, could increase cAMP levels in these sympathetic neurons, and delay neuronal cell death resulting from NGF deprivation. These results suggest that PACAP may serve as a neurotrophic factor in sympathetic neurons.


Subject(s)
Apoptosis , Cyclic AMP/metabolism , Ganglia, Sympathetic/metabolism , Neurons/physiology , Animals , Cellular Senescence , Ganglia, Sympathetic/cytology , Ganglia, Sympathetic/drug effects , Nerve Growth Factors/deficiency , Nerve Growth Factors/physiology , Neurons/drug effects , Neurons/metabolism , Neuropeptides/pharmacology , Pituitary Adenylate Cyclase-Activating Polypeptide , Rats , Rats, Sprague-Dawley
12.
Neurotoxicology ; 18(1): 129-35, 1997.
Article in English | MEDLINE | ID: mdl-9215995

ABSTRACT

Tunicamycin (TM) is known to cause severe neurological diseases in the central nervous system of animals. Cultured cerebellar granule cells were used to investigate the direct cytotoxicity of this agent on cerebellar neurons. Results indicate that TM is a potent inhibitor of glycosylation and protein synthesis. This agent killed granule cells in a dose- and time-dependent manner. TM treatment of these neurons lead to atrophic cell bodies and condensed nuclei. This TM-induced cell death could be prevented by cycloheximide and aurintricarboxylic acid. In contrast, TM had no apparent toxicity toward nerve growth factor-differentiated PC12 cells under similar conditions. These results suggest that TM kills cerebellar granule cells in a manner similar to programmed cell death.


Subject(s)
Cerebellum/drug effects , Neurons/drug effects , Neurotoxins/toxicity , Protein Synthesis Inhibitors/toxicity , Tunicamycin/toxicity , Animals , Apoptosis/drug effects , Cell Differentiation/drug effects , Cells, Cultured , Cerebellum/cytology , Glycosylation , Nerve Growth Factors/pharmacology , PC12 Cells , Rats , Rats, Sprague-Dawley
13.
Neurosci Lett ; 206(2-3): 181-4, 1996 Mar 15.
Article in English | MEDLINE | ID: mdl-8710181

ABSTRACT

Cultured cerebellar granule cells undergo programmed cell death when they are deprived of depolarizing KCl. Results from this study indicate that the cAMP analog cyclic 8-(4-chlorophenylthio) adenosine-3'5'-monophosphate (CPT-cAMP) can prevent the cell death in a dose-dependent manner, with the maximal effect seen at 500 microM. Approximately 70% of cells can be saved with this concentration of CPT-cAMP for at least 6 days. Pituitary adenylate cyclase-activating polypeptide (PACAP) increased the intracellular cAMP levels of these cells in a time- and dose-dependent manner. This agent can prevent the decrease of cAMP and cell death induced by KCl withdrawal. These results suggest that PACAP could function as a neurotrophic factor for cerebellar granule cells in vivo.


Subject(s)
Apoptosis/drug effects , Cerebellum/drug effects , Cyclic AMP/pharmacology , Neurons/drug effects , Neuropeptides/pharmacology , Animals , Cells, Cultured , Cerebellum/cytology , Neurons/cytology , Pituitary Adenylate Cyclase-Activating Polypeptide , Rats , Rats, Sprague-Dawley
14.
Exp Neurol ; 137(2): 201-11, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8635535

ABSTRACT

Tunicamycin belongs to a group of antibiotics which can cause severe a nd often fatal neurological malfunction in animals, commonly known as "annual ryegrass toxicity." At the cellular level, tunicamycin is a potent glycosylation inhibitor which is often used to elucidate the importance of glycosylation in protein functions. Earlier reports suggested that tunicamycin was able to interfere with the binding of nerve growth factor to its receptors. In this report, we showed that tunicamycin was able to kill sympathetic neurons in cultures. The mechanism of cell death was observed to be similar to that of "programmed cell death" in sympathetic neurons induced by nerve growth factor deprivation. Such tunicamycin-induced cell death could be prevented by the protein synthesis inhibitor cycloheximide, which was known to prevent the programmed cell death in sympathetic neurons. These results demonstrated that, in addition to the proven CNS neurotoxicity in animals, tunicamycin causes programmed cell death in peripheral (sympathetic) neurons.


Subject(s)
Apoptosis/drug effects , Neurons/drug effects , Receptors, Nerve Growth Factor/drug effects , Sympathetic Nervous System/drug effects , Tunicamycin/toxicity , Animals , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Glycosylation/drug effects , Rats , Rats, Sprague-Dawley , Time Factors
15.
Med Parazitol (Mosk) ; (1): 37-40, 1996.
Article in Russian | MEDLINE | ID: mdl-8700011

ABSTRACT

Histological and electron microscopic techniques were used to study the structure of the kidney in migration ascariasis caused by the single or double infection of white mice with Ascaris at an interval of 14 days. The animals were autopsied on days 5-7 after single or double infection. It was found that double infection changes occur earlier (on day 2). The kidneys were ascertained to restore their structure by day 21, suggesting the reversibility of the detected changes. Such regularity has been defined before while examining the structure of the liver in ascariasis.


Subject(s)
Ascariasis/pathology , Kidney/pathology , Animals , Mice , Microscopy, Electron , Time Factors
16.
Med Tr Prom Ekol ; (1): 8-11, 1995.
Article in Russian | MEDLINE | ID: mdl-7757384

ABSTRACT

The state of peripheral and central hemodynamics was examined in 603 workers engaged into shifted duty expeditions in West Siberia, considering the length of service in the shifted duty cycle. The examination revealed high occurrence of cardiovascular diseases with prevalent hypertension. Rheographic findings proved that in 5 years of the shifted duty work high blood pressure develops with increased peripheral vascular tone (especially in brain) and enhanced contractility of left ventricle. Important role in the high blood pressure formation is played by changes of hemodynamics in first days after the duty shift.


Subject(s)
Hypertension/etiology , Occupational Diseases/etiology , Adult , Hemodynamics , Humans , Hypertension/diagnosis , Male , Occupational Diseases/diagnosis , Siberia , Time Factors
18.
Vopr Onkol ; 38(2): 205-8, 1992.
Article in Russian | MEDLINE | ID: mdl-1300707

ABSTRACT

The results of treatment of 19 cases of inoperable squamous cell tumors of the head and neck are discussed. The treatment schedule used three drugs: 100 mg/m2 cisplatin at day 1, 25 mg/m2 methotrexate, intravenously, at day 4, and a total of 1000 mg/m2 5-fluorouracil, at days 4-8 of treatment, by continuous 120 hour-long infusion. Effect was observed in 15 patients. The treatment was effective in 47.4% (complete regression--in 1 case, morphologically confirmed and partial regression--in 8 cases), stabilization--in 26.3 (5 patients) and further progression--in 26.3% (5 patients). Among the untoward side-effects were nausea, vomiting, anorexia, stomatitis and diarrhea. The toxicity proved tolerable.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Squamous Cell/drug therapy , Head and Neck Neoplasms/drug therapy , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Cisplatin/administration & dosage , Cisplatin/adverse effects , Drug Evaluation , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Humans , Male , Methotrexate/administration & dosage , Methotrexate/adverse effects , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Remission Induction , Time Factors
20.
Vestn Khir Im I I Grek ; 146(5): 97-9, 1991 May.
Article in Russian | MEDLINE | ID: mdl-1668470

ABSTRACT

An electrocardiographic evaluation of the functional state of the myocardium in patients operated upon for urological diseases under conditions of low epidural anesthesia has shown that in the absence of a cardiovascular pathology the method of anesthesia fails to exert a substantial influence on the circulation homeokinesis and functional state of the myocardium. The following use of the low epidural anesthesia in 105 patients with a coexistent ischemic heart disease during urological operative interventions results in two times less amount of cardiovascular complications, lethality and duration of the postoperative period.


Subject(s)
Anesthesia, Epidural/methods , Coronary Disease/physiopathology , Urologic Diseases/surgery , Adult , Aged , Aged, 80 and over , Anesthesia, Epidural/adverse effects , Electrocardiography , Female , Heart/physiopathology , Hemodynamics/physiology , Humans , Male , Middle Aged , Postoperative Period , Urologic Diseases/physiopathology
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