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1.
Sud Med Ekspert ; 65(1): 52-56, 2022.
Artigo em Russo | MEDLINE | ID: mdl-35142473

RESUMO

The literature review presents data on pathomorphological changes in the kidneys in acute and chronic alcohol intoxication. A lack of consensus among researchers on the direct toxic damage to renal tissue by ethanol is demonstrated. Analysis of the literature showed that the issue of attributing microscopic changes detected in the kidneys to characteristic or specific signs remains controversial. Some authors identify several characteristic microscopic patterns in the kidney tissue in alcohol intoxication: thickening of glomeruli basal membranes, narrowing of glomerular capsule tubular lumen. Fatty dystrophy of the proximal tubules is most often indicative of concomitant conditions related to alcohol intoxication, such as ketoacidosis. In alcohol intoxication, some changes in the kidneys occur variably, such as dyscirculatory, dystrophic, pigmentary, necrotic, and autolytic changes. Data on the causes of their occurrence are often contradictory from different authors. The authors of this review believe that this issue can be resolved using up-to-date histochemical, immunohistochemical, and morphometric test methods.


Assuntos
Intoxicação Alcoólica , Alcoolismo , Intoxicação Alcoólica/complicações , Alcoolismo/complicações , Etanol/toxicidade , Humanos , Rim
2.
Sci Rep ; 7(1): 17370, 2017 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-29234110

RESUMO

The compound Sr0.5Ce0.5FBiS2 belongs to the intensively studied family of layered BiS2 superconductors. It attracts special attention because superconductivity at T sc = 2.8 K was found to coexist with local-moment ferromagnetic order with a Curie temperature T C = 7.5 K. Recently it was reported that upon replacing S by Se T C drops and ferromagnetism becomes of an itinerant nature. At the same time T sc increases and it was argued superconductivity coexists with itinerant ferromagnetism. Here we report a muon spin rotation and relaxation study (µSR) conducted to investigate the coexistence of superconductivity and ferromagnetic order in Sr0.5Ce0.5FBiS2-x Se x with x = 0.5 and 1.0. By inspecting the muon asymmetry function we find that both phases do not coexist on the microscopic scale, but occupy different sample volumes. For x = 0.5 and x = 1.0 we find a ferromagnetic volume fraction of ~8 % and ~30 % at T = 0.25 K, well below T C = 3.4 K and T C = 3.3 K, respectively. For x = 1.0 (T sc = 2.9 K) the superconducting phase occupies most (~64 %) of the remaining sample volume, as shown by transverse field experiments that probe the Gaussian damping due to the vortex lattice. We conclude ferromagnetism and superconductivity are macroscopically phase separated.

3.
Sci Rep ; 6: 28632, 2016 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-27350295

RESUMO

Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms.

4.
J Phys Condens Matter ; 27(27): 275701, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26086396

RESUMO

We report a study of the magnetic and electronic properties of the non-centrosymmetric half-Heusler antiferromagnet HoPdBi (TN = 2.0 K). Magnetotransport measurements show HoPdBi has a semimetallic behavior with a carrier concentration n = 3.7 × 10(18) cm(-3) extracted from the Shubnikov-de Haas effect. The magnetic phase diagram in the field-temperature plane has been determined by transport, magnetization, and thermal expansion measurements: magnetic order is suppressed at BM ~ 3.6 T for T --> 0. Superconductivity with Tc ~ 1.9 K is found in the antiferromagnetic phase. Ac-susceptibility measurements provide solid evidence for bulk superconductivity below Tc = 0.75 K with a screening signal close to a volume fraction of 100%. The upper critical field shows an unusual linear temperature variation with Bc2(T --> 0) = 1.1 T. We also report electronic structure calculations that classify HoPdBi as a new topological semimetal, with a non-trivial band inversion of 0.25 eV.

5.
Biofizika ; 57(2): 232-42, 2012.
Artigo em Russo | MEDLINE | ID: mdl-22594278

RESUMO

Data obtained show that antiviral activities of bis-linked netropsin derivatives are targeted by specific complexes formed by helicase UL9 of herpes simplex virus type 1 with viral DNA replication origins, represented by two OriS sites and one OriL site. According to the results of footprinting studies bis-netropsins get bound selectively to an A+T-cluster which separates interaction sites I and II for helicase UL9 in OriS. Upon binding to DNA bis-netropsins stabilize a structure of the A+T-cluster and inhibit thermal fluctuation-induced opening of AT- base pairs which is needed for local unwinding of DNA by helicase UL9. Kinetics of ATP-dependent DNA unwinding in the presence and absence of Pt-bis-netropsin are studied by measuring the efficiency of Forster resonance energy transfer (FRET) between the fluorescent probes attached covalently to 3?- and 5?-ends of the oligonucleotides in the minimal OriS duplex. Pt-bis-netropsin and related molecules inhibit unwinding of OriS duplex by helicase UL9. Pt-bis-netropsin is also able to reduce the rate of unwinding of the AT- rich hairpin formed by the upper strand in the minimal OriS duplex. The antiviral activities and toxicity of bis-linked netropsin derivatives are studied in cell cultured experiments and experiments with animals infected by herpes virus.


Assuntos
Antivirais/farmacologia , Replicação do DNA/efeitos dos fármacos , DNA Viral/metabolismo , Proteínas de Ligação a DNA , Herpes Simples , Herpesvirus Humano 1/enzimologia , Netropsina/farmacologia , Proteínas Virais , Animais , Chlorocebus aethiops , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Herpes Simples/tratamento farmacológico , Herpes Simples/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Netropsina/análogos & derivados , Células Vero , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/metabolismo
6.
J Biomol Struct Dyn ; 26(6): 701-18, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19385699

RESUMO

In the present work, we employed UV-VIS spectroscopy, fluorescence methods, and circular dichroism spectroscopy (CD) to study the interaction of dye Hoechst 33258, Hoechst 33342, and their derivatives to poly[d(AT)].poly[d(AT)], poly(dA).poly(dT), and DNA dodecamer with the sequence 5'-CGTATATATACG-3'. We identified three types of complexes formed by Hoechst 33258, Hoechst 33342, and methylproamine with DNA, corresponding to the binding of each drug in monomer, dimer, and tetramer forms. In a dimer complex, two dye molecules are sandwiched in the same place of the minor DNA groove. Our data show that Hoechst 33258, Hoechst 33342, and methylproamine also form complexes of the third type that reflects binding of dye associates (probably tetramers) to DNA. Substitution of a hydrogen atom in the ortho position of the phenyl ring by a methyl group has a little effect on binding of monomers to DNA. However it reduces strength of binding of tetramers to DNA. In contrast, a Hoechst derivative containing the ortho-isopropyl group in the phenyl ring exhibits a low affinity to poly(dA).poly(dT) and poly[d(AT)].poly[d(AT)] and binds to DNA only in the monomer form. This can be attributed to a sterical hindrance caused by the ortho-isopropyl group for side-by-side accommodation of two dye molecules in the minor groove. Our experiments show that mode of binding of Hoechst 33258 derivatives and their affinity for DNA depend on substituents in the ortho position of the phenyl ring of the dye molecule. A statistical mechanical treatment of binding of Hoechst 33258 and its derivatives to a polynucleotide lattice is described and used for determination of binding parameters of Hoechst 33258 and its derivatives to poly[d(AT)].poly[d(AT)] and poly(dA).poly(dT).


Assuntos
Benzimidazóis/química , Bisbenzimidazol/química , DNA/química , Sequência de Bases , Sítios de Ligação , Ligação Competitiva , Dicroísmo Circular , Cinética , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , Oligonucleotídeos/química , Poli T/química , Poli dA-dT/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Termodinâmica
7.
Biofizika ; 49(6): 1053-60, 2004.
Artigo em Russo | MEDLINE | ID: mdl-15612546

RESUMO

Sequences of spidroin 1 and 2 from spiders belonging to various species were analyzed by Fourier analysis. Specific periodical patterns were found in various segments of the sequences. These characteristic periodicities vary within the same proteins as well as between spidroin 1 and spidroin 2 sequences. It is possible that alterations in periodicity help to recognize contact sites between the molecules. Spidroins of 2 type have similar sequence structure consisting of four parts with a particular periodical pattern. These parts are a constant C-terminal part, a long-periodical part, a short-periodical part, and a constant N-terminal part.


Assuntos
Fibroínas/química , Proteínas de Insetos/química , Seda/química , Aranhas/química , Sequência de Aminoácidos , Animais , Bases de Dados de Proteínas , Análise de Fourier , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Software , Especificidade da Espécie
11.
J Biomol Struct Dyn ; 18(5): 689-701, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11334106

RESUMO

Cis-diammine Pt(II)- bridged bis-netropsin and oligomethylene-bridged bis-netropsin in which two monomers are linked in a tail-to-tail manner bind to the DNA oligomer with the sequence 5'-CCTATATCC-3' in a parallel-stranded hairpin form with a stoichiometry 1:1. The difference circular dichroism (CD) spectra characteristic of binding of these ligands in the hairpin form are similar. They differ from CD patterns obtained for binding to the same duplex of another bis-netropsin in which two netropsin moieties were linked in a head-to-tail manner. This reflects the fact that tail-to-tail and head-to-tail bis-netropsins use parallel and antiparallel side-by-side motifs, respectively, for binding to DNA in the hairpin forms. The binding affinity of cis-diammine Pt(II)-bridged bis-netropsin in the hairpin form to DNA oligomers with nucleotide sequences 5'-CCTATATCC-3' (I), 5'-CCTTAATCC-3' (II), 5'-CCTTATTCC-3' (III), 5'-CCTTTTTCC-3' (IV) and 5'-CCAATTTCC-3' (V) decreases in the order I = II > III > IV > V . The binding of oligomethylene-bridged bis-netropsin in the hairpin form follows a similar hierarchy. An opposite order of sequence preferences is observed for partially bonded monodentate binding mode of the synthetic ligand.


Assuntos
DNA/química , Netropsina/análogos & derivados , Netropsina/química , Sítios de Ligação , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Poli dA-dT/química
12.
Dis Colon Rectum ; 40(6): 679-84, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9194462

RESUMO

PURPOSE: This study was designed to estimate the efficiency of the various methods used to treat familial adenomatous polyposis coli. METHODS: Three hundred ninety patients (219 males) underwent surgery for familial adenomatous polyposis coli; postoperative follow-up was from 1 to 30 years. RESULTS: Coloproctectomy with preservation of the anal sphincter and coloproctectomy with ileoanal pull-through procedures resulted in development of anal canal cancer in 3 (4.1 percent) of 74 patients. Follow-up revealed development of cancer in the large bowel in 26 (10.7 percent) of 242 patients, in whom colectomy with preservation of various colonic segments was performed. CONCLUSIONS: The occurrence rate of cancer is not significantly related to patients' gender, age, length of preserved colonic segment, presence of cancer in the removed colonic segment, or postoperative follow-up period; however, presence of polyps in the colonic segments preserved during surgery significantly increased the risk of development of cancer at a later time.


Assuntos
Polipose Adenomatosa do Colo/cirurgia , Polipose Adenomatosa do Colo/complicações , Adulto , Neoplasias do Ânus/epidemiologia , Neoplasias do Ânus/etiologia , Neoplasias do Colo/epidemiologia , Neoplasias do Colo/etiologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de Risco
15.
FEBS Lett ; 375(3): 304-6, 1995 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-7498523

RESUMO

An unusual 3:1 stoichiometry for complex formation between an elongated bis-netropsin compound and its binding site on DNA has been observed. Circular dichroism measurements distinguish two types of complexes formed between this bis-netropsin and poly[d(A-T)].poly[d(A-T)]. The first type is characterized by a 1:1 saturating ratio of bound molecules per ten base pairs. Formation of the second type results from the cooperative binding of two additional bis-netropsin molecules to the first type of complex. In contrast to these results observed for binding to the alternating polynucleotide, only the 1:1 type of complex is formed when this ligand binds to the homopolymer poly(dA).poly(dT).


Assuntos
DNA/química , Netropsina/análogos & derivados , Conformação de Ácido Nucleico , Poli dA-dT/química , Dicroísmo Circular , Cinética , Netropsina/química
16.
Mol Biol (Mosk) ; 29(4): 848-61, 1995.
Artigo em Russo | MEDLINE | ID: mdl-7476952

RESUMO

Nevel synthetic DNA binding ligands containing N,4-disubstituted mono- and diphthalimide fragments and carrying positively charged groups at both ends of the molecules were characterized by various physiochemical methods. All the ligands were shown to have fluorescence maximum at about 460 nm for excitation at 340 nm. Interaction of these compounds with DNA and synthetic polydeoxyribonucleotides was studied using spectrophotometry, CD and fluorescence measurements. It was shown, that the ligand containing phthalimide fragment connected by flexible chain to dipyrrolcarboxamide fragment, binds to DNA narrow groove covering 5 base pairs. This type of complex formation was found to be followed by increasing of CD band at 280 nm and increasing in fluorescence intensity. If the ligand backbone contains only phthalimide fragments there is no binding in the DNA narrow groove. In this case the weakly fluorescent outside binding type complex is formed, which is characterized by the binding of one ligand molecule with two base pairs.


Assuntos
DNA/química , Ftalimidas/química , Dicroísmo Circular , Ligantes , Espectrometria de Fluorescência
18.
Khirurgiia (Mosk) ; (4): 38-41, 1994 Apr.
Artigo em Russo | MEDLINE | ID: mdl-8041072

RESUMO

Among 390 patients who were operated on in the Research Institute of Proctology for the proliferative form of diffuse polyposis, 242 underwent various types of operations in which polyp-free segments of the large intestine were not resected. In the first 5 postoperative years all 242 patients were examined, in follow-up periods of 6 to 10 years 144 patients (59.5%), in periods of 11 to 15 years 88 patients (36.4%), in periods of 16 to 20 years 28 patients (11.6%), and after 21 years 8 patients (3.3%) were examined. Development of carcinoma in the preserved segments was encountered in 26 patients (10.7%), and intensive growth of polyps for which the preserved segment had to be removed was found in 5 patients (2.1%). There was no significant increase of the risk of carcinoma development in the preserved intestinal segments in patients who previously had a malignant tumor in the resected part of the large intestine. The development of carcinoma and intensive growth of polyps were encountered most frequently in patients in whom the distal parts of the large intestine were not removed during the operation. The obtained data are evidence of the validity of the choice of the volume of the operation based on the endeavor to preserve the polyp-free parts of the large intestine for rehabilitation of the patients.


Assuntos
Neoplasias Intestinais/cirurgia , Pólipos Intestinais/cirurgia , Intestino Grosso/cirurgia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Neoplasias Intestinais/patologia , Pólipos Intestinais/patologia , Intestino Grosso/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Cuidados Pós-Operatórios , Fatores de Risco , Procedimentos Cirúrgicos Operatórios/métodos , Resultado do Tratamento
19.
Khirurgiia (Mosk) ; (10): 53-7, 1993 Oct.
Artigo em Russo | MEDLINE | ID: mdl-8295383

RESUMO

Diffuse polyposis of the large intestine characterized by the development of multiple polyps in it and their subsequent malignant degeneration is one of the most severe disease of the gastrointestinal tract. That it must be treated by surgery needs no proof. However, the volume and the character of the surgical intervention on the large intestine is still a debatable problem. The article discusses the experience in the follow-up of 445 patients for periods of 12 months to 30 years after operation for diffuse polyposis. In 228 patients various segments of the large intestine which were free from polyps were not resected. During these follow-up periods malignant tumors developed in the preserved parts of the large intestine in 10.1% patients and intensive growth of polyps was encountered in 3.5% of patients. The frequency of carcinoma development depended significantly less on the length of the follow-up period and much more on the character of affection of the preserved parts of the large intestine with the polyps.


Assuntos
Colectomia/métodos , Pólipos do Colo/cirurgia , Adolescente , Adulto , Idoso , Neoplasias do Colo/etiologia , Pólipos do Colo/complicações , Pólipos do Colo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Lik Sprava ; (8): 109-11, 1993 Jul.
Artigo em Russo | MEDLINE | ID: mdl-8079463

RESUMO

Malaria morbidity in Sevastopol in 1944 was 3192 per 100,000. Efforts on malaria control has resulted in liquidation of the disease in the town. For twenty years (1955-1974) infection had not been reported. There were 42 cases diagnosed from 1975 to 1991 in patients who had arrived from Asia and Africa. One patient died of tropic malaria. Measures against malaria should be carried out the whole year round in order to prevent outbreak of this grave infection in the town.


Assuntos
Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Malária/epidemiologia , Plasmodium malariae , População Urbana/estatística & dados numéricos , África/etnologia , Animais , Humanos , Incidência , Malária/transmissão , Malária Falciparum/transmissão , Malária Vivax/transmissão , Ucrânia/epidemiologia
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