Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Cell Surf ; 8: 100079, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35757110

RESUMO

Proteus mirabilis harbours a variety of O antigens, permitting evasion of the host immune response. LPS decoration with phosphocholine increases cell surface hydrophobicity and decreases electrokinetic potential, which may interfere with antibody interaction and bacterial surface recognition. The decoration does not influence adherence to solid surfaces.

2.
Eur J Psychol ; 18(4): 422-436, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36605086

RESUMO

The relationships between self-report loneliness and the four humor styles of affiliative, aggressive, self-defeating, and self-enhancing were investigated in 15 countries (N = 4,701). Because loneliness has been suggested to be both commonly experienced and detrimental, we examine if there are similar patterns between humor styles, gender, and age with loneliness in samples of individuals from diverse backgrounds. Across the country samples, affiliative and self-enhancing humor styles negatively correlated with loneliness, self-defeating was positively correlated, and the aggressive humor style was not significantly related. In predicting loneliness, 40.5% of the variance could be accounted. Younger females with lower affiliative, lower self-enhancing, and higher self-defeating humor style scores had higher loneliness scores. The results suggest that although national mean differences may be present, the pattern of relationships between humor styles and loneliness is consistent across these diverse samples, providing some suggestions for mental health promotion among lonely individuals.

3.
Life (Basel) ; 11(6)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208435

RESUMO

Inhibitors of 3-hydroxy-3methylgultaryl-coenzyme A reductase (statins) are one of the main groups of drugs used in preventing and treating cardiovascular diseases worldwide. They are widely available, cheap, and well-tolerated. Based on statins' pleiotropic properties, including improvement of endothelial dysfunction, antioxidant properties, atherosclerotic plaque stabilization, and inhibition of inflammatory responses, it can be hypothesized that the use of statins, at least as an adjuvant in antiviral therapy, may be justified. All these effects might be especially beneficial in patients with COVID-19, suffering from endothelial dysfunction, microvascular and macrovascular thrombosis, and cytokine storm. Here, we review the recent data regarding the pathophysiology of SARS-CoV-2 activity in host cells, proposed COVID-19 therapy, the pleiotropic activity of statins, and statins in clinical trials in respiratory infections. According to the guidelines of the European and American Cardiac Societies, in patients with cardiovascular disease or high cardiovascular risk with concomitant COVID-19 it is recommended to continue statin treatment. However, the initiation of statin therapy de novo in COVID-19 treatment should only be done as part of a clinical trial.

4.
J Pers ; 89(2): 338-356, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33448386

RESUMO

OBJECTIVE: We investigated how Dark Triad traits influence the development and maintenance of social relations. METHOD: Participants completed the Short Dark Triad questionnaire and a measure of social relations at three time points: at the beginning of their first year in high school, 3 months later, and at the end of their first year. We investigated whether the Dark Triad traits are stable over time using Multilevel Modeling (N = 265; 59.6% girls), and how Dark Triad traits predict incoming and outgoing agentic and communal relations using Temporal Exponential Random Graph Models (N = 192; 60.4% girls). RESULTS: Overall, the Dark Triad traits were stable over a one-year period. Narcissism did not predict an increase in communal and agentic relations in the short-term, but predicted slightly less incoming communal and more agentic relations in the long-term. In the short-term, Machiavellianism predicted a small increase while psychopathy predicted a small decrease in the incoming agentic and communal relations. In the long-term, however, neither Machiavellianism nor psychopathy was a significant predictor of any incoming relations. CONCLUSIONS: Our results shed new light on the dynamics of making and maintaining social relations through the prism of the Dark Triad traits.


Assuntos
Maquiavelismo , Narcisismo , Transtorno da Personalidade Antissocial , Feminino , Humanos , Masculino , Rede Social , Inquéritos e Questionários
5.
Cells ; 9(8)2020 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-32722473

RESUMO

The cuticle commonly appears as a continuous lipophilic layer located at the outer epidermal cell walls of land plants. Cutin and waxes are its main components. Two methods for cutin synthesis are considered in plants. One that is based on enzymatic biosynthesis, in which cutin synthase (CUS) is involved, is well-known and commonly accepted. The other assumes the participation of specific nanostructures, cutinsomes, which are formed in physicochemical self-assembly processes from cutin precursors without enzyme involvement. Cutinsomes are formed in ground cytoplasm or, in some species, in specific cytoplasmic domains, lipotubuloid metabolons (LMs), and are most probably translocated via microtubules toward the cuticle-covered cell wall. Cutinsomes may additionally serve as platforms transporting cuticular enzymes. Presumably, cutinsomes enrich the cuticle in branched and cross-linked esterified polyhydroxy fatty acid oligomers, while CUS1 can provide both linear chains and branching cutin oligomers. These two systems of cuticle formation seem to co-operate on the surface of aboveground organs, as well as in the embryo and seed coat epidermis. This review focuses on the role that cutinsomes play in cuticle biosynthesis in S. lycopersicum, O. umbellatum and A. thaliana, which have been studied so far; however, these nanoparticles may be commonly involved in this process in different plants.


Assuntos
Parede Celular/metabolismo , Lipídeos de Membrana/metabolismo , Proteínas de Plantas/metabolismo
6.
Int J Psychol ; 55(3): 413-424, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31245844

RESUMO

A recent re-operationalisation of grandiose narcissism has resulted in the distinction of two narcissistic strategies based on the cognitive, affective-motivational and behavioural dynamics: admiration (assertive self-enhancement) and rivalry (antagonistic self-protection). The Narcissistic Admiration and Rivalry Questionnaire (NARQ) was developed to assess this model with two higher-order dimensions. However, cross-validations of the NARQ have not been extensively conducted across diverse population groups and languages. This study aimed to test the internal and external validity (through the relation with envy and self-esteem), reliability and cross-cultural equivalence of the Spanish version of the NARQ. The psychometric properties were evaluated in a Spanish sample (N = 310), and cross-cultural equivalence was tested in participants from Chile (N = 234) and Colombia (N = 256). The results supported the reliability and validity of the Spanish NARQ, as well as the cross-cultural equivalence across Spanish-speaking countries. In addition, we discuss obtained differences across Spanish, Chilean and Colombian sample within two narcissistic strategies.


Assuntos
Narcisismo , Psicometria/métodos , Adulto , Comparação Transcultural , Feminino , Humanos , Idioma , Masculino , Reprodutibilidade dos Testes , Inquéritos e Questionários , Adulto Jovem
7.
Front Psychol ; 9: 343, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29593627

RESUMO

Grandiose and vulnerable narcissism seem to be uncorrelated in empirical studies, yet they share at least some theoretical similarities. In the current study, we examine the relation between grandiose (conceptualized as admiration and rivalry) and vulnerable narcissism in the context of the Big Five personality traits and metatraits, self-esteem, and their nomological network. To this end, participants (N = 314) filled in a set of self-report measures via an online survey. Rivalry was positively linked with both admiration and vulnerable narcissism. We replicated the relations of admiration and rivalry with personality traits and metatraits-as well as extended existing knowledge by providing support for the theory that vulnerable narcissism is simultaneously negatively related to the Stability and Plasticity. Higher scores on vulnerable narcissism and rivalry predicted having fragile self-esteem, whereas high scores on admiration predicted having optimal self-esteem. The assumed relations with the nomological network were confirmed, i.e., vulnerable narcissism and admiration demonstrated a contradictory pattern of relation to shyness and loneliness, whilst rivalry predicted low empathy. Our results suggest that the rivalry is between vulnerable narcissism and admiration, which supports its localization in the self-importance dimension of the narcissism spectrum model. It was concluded that whereas admiration and rivalry represent the bright and dark face of narcissism, vulnerable narcissism represents its blue face.

8.
Physiol Plant ; 161(4): 560-567, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28767133

RESUMO

Cutinsomes, spherical nanoparticles containing cutin mono- and oligomers, are engaged in cuticle formation. Earlier they were revealed to participate in cuticle biosynthesis in Solanum lycopersicum fruit and Ornithogalum umbellatum ovary epidermis. Here, transmission electron microscopy (TEM) and immunogold labeling with antibody against the cutinsomes were applied to aerial cotyledon epidermal cells of Arabidopsis thaliana mature embryos. TEM as well as gold particles conjugated with the cutinsome antibody revealed these structures in the cytoplasm, near the plasmalemma, in the cell wall and incorporated into the cuticle. Thus, the cutinsomes most probably are involved in the formation of A. thaliana embryo cuticle and this model plant is another species in which these specific structures participate in the building of cuticle in spite of the lack of the lipotubuloid metabolon. In addition, a mechanism of plant cuticle lipid biosynthesis based on current knowledge is proposed.


Assuntos
Arabidopsis/metabolismo , Arabidopsis/genética , Cotilédone/genética , Cotilédone/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Microscopia Eletrônica de Transmissão , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismo
9.
Micron ; 85: 51-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27088229

RESUMO

In the ovary epidermis of O. umbellatum there are lipotubuloid metabolons (LMs), in which synthesis of lipids takes place. This process partly provides nourishment, and partly cuticle building blocks, transformed, among others, with the participation of cutinsomes. The cutinsomes are cutin-building structures, 40-200nm in size, which are formed as a result of self-assembly and self-esterification of hydroxy fatty acids. The cutinsomes, by binding to the cuticle, introduce into it nonlinear, amorphous and cross-linked polymers. Double-immunogold EM observations revealed that enzymes producing elements of cutin (GPAT6) and waxes (WS/DGAT) were found not only as free cytoplasmic molecules but also in many cases they were bound to carboxylate-carboxylic shell of cuntinsomes. Hence, we suppose that these enzymes can move alone or together with the cutinsomes through cytoplasm (pH 6.8-7.0), plasmalemma and the polysaccharide layer of a cell wall to the site of their functioning i.e. to the cuticle (pH 5.0).


Assuntos
Diacilglicerol O-Aciltransferase/metabolismo , Flores/metabolismo , Glicerol-3-Fosfato O-Aciltransferase/metabolismo , Liliaceae/metabolismo , Metabolismo dos Lipídeos , Lipídeos de Membrana/química , Epiderme Vegetal/metabolismo , Arabidopsis/enzimologia , Arabidopsis/fisiologia , Membrana Celular/química , Membrana Celular/enzimologia , Membrana Celular/fisiologia , Parede Celular/química , Parede Celular/enzimologia , Parede Celular/fisiologia , Matriz Extracelular/metabolismo , Liliaceae/enzimologia , Nanopartículas/química , Proteínas de Plantas/metabolismo
10.
J Exp Bot ; 66(5): 1157-63, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25540439

RESUMO

A metabolon is a temporary, structural-functional complex formed between sequential metabolic enzymes and cellular elements. Cytoplasmic domains called lipotubuloids are present in Ornithogalum umbellatum ovary epidermis. They consist of numerous lipid bodies entwined with microtubules, polysomes, rough endoplasmic reticulum (RER), and actin filaments connected to microtubules through myosin and kinesin. A few mitochondria, Golgi structures, and microbodies are also observed and also, at later development stages, autolytic vacuoles. Each lipotubuloid is surrounded by a tonoplast as it invaginates into a vacuole. These structures appear in young cells, which grow intensively reaching 30-fold enlargement but do not divide. They also become larger due to an increasing number of lipid bodies formed in the RER by the accumulation of lipids between leaflets of the phospholipid bilayer. When a cell ceases to grow, the lipotubuloids disintegrate into individual structures. Light and electron microscope studies using filming techniques, autoradiography with [(3)H]palmitic acid, immunogold labelling with antibodies against DGAT2, phospholipase D1 and lipase, and double immunogold labelling with antibodies against myosin and kinesin, as well as experiments with propyzamide, a microtubule activity inhibitor, have shown that lipotubuloids are functionally and structurally integrated metabolons [here termed lipotubuloid metabolons (LMs)] occurring temporarily in growing cells. They synthesize lipids in lipid bodies in cooperation with microtubules. Some of these lipids are metabolized and used by the cell as nutrients, and others are transformed into cuticle whose formation is mediated by cutinsomes. The latter were discovered in planta using specific anti-cutinsome antibodies visualized by gold labelling. Moreover, LMs are able to rotate autonomously due to the interaction of microtubules, actin filaments, and motor proteins, which influence microtubules by changing their diameter.


Assuntos
Flores/metabolismo , Metabolismo dos Lipídeos , Ornithogalum/metabolismo , Epiderme Vegetal/metabolismo , Citoesqueleto de Actina/metabolismo , Microtúbulos/metabolismo , Proteínas de Plantas/metabolismo
11.
Protoplasma ; 251(5): 1151-61, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24627134

RESUMO

The outer wall of Ornithogalum umbellatum ovary and the fruit epidermis are covered with a thick cuticle and contain lipotubuloids incorporating (3)H-palmitic acid. This was earlier evidenced by selective autoradiographic labelling of lipotubuloids. After post-incubation in a non-radioactive medium, some marked particles insoluble in organic solvents (similar to cutin matrix) moved to the cuticular layer. Hence, it was hypothesised that lipotubuloids participated in cuticle synthesis. It was previously suggested that cutinsomes, nanoparticles containing polyhydroxy fatty acids, formed the cuticle. Thus, identification of the cutinsomes in O. umbellatum ovary epidermal cells, including lipotubuloids, was undertaken in order to verify the idea of lipotubuloid participation in cuticle synthesis in this species. Electron microscopy and immunogold method with the antibodies recognizing cutinsomes were used to identify these structures. They were mostly found in the outer cell wall, the cuticular layer and the cuticle proper. A lower but still significant degree of labelling was also observed in lipotubuloids, cytoplasm and near plasmalemma of epidermal cells. It seems that cutinsomes are formed in lipotubuloids and then they leave them and move towards the cuticle in epidermal cells of O. umbellatum ovary. Thus, we suggest that (1) cutinsomes could take part in the synthesis of cuticle components also in plant species other than tomato, (2) the lipotubuloids are the cytoplasmic domains connected with cuticle formation and (3) this process proceeds via cutinsomes.


Assuntos
Flores/crescimento & desenvolvimento , Microtúbulos/metabolismo , Ornithogalum/crescimento & desenvolvimento , Epiderme Vegetal/crescimento & desenvolvimento , Parede Celular/metabolismo , Ácidos Graxos/biossíntese , Flores/citologia , Imuno-Histoquímica , Lipídeos de Membrana/biossíntese , Microscopia Eletrônica , Ornithogalum/citologia , Ácido Palmítico/metabolismo , Epiderme Vegetal/citologia
12.
J Matern Fetal Neonatal Med ; 27(11): 1142-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24093539

RESUMO

AIM: Aim of this study was to assess concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-18 (IL-18) in the serum of newborns with diagnosed intrauterine growth restriction (IUGR) in comparison to concentrations in serum of newborns with weight appropriate for gestational age (AGA). MATERIALS: Research was conducted at the Lodz Medical University Clinic of Neonatology during 2010-2011. Surveyed group consisted of 50 hypotrophic full-term infants of single pregnancies (average weight: 2329 ± 287 g); control group, enclosing 50 infants AGA (average weight: 3544 ± 2161 g). Both groups received average Apgar score of 9 points. Concentrations of analysed cytokines were marked between 4-6 hours after birth. The enzyme-linked immunosorbent assay (ELISA) test was used to determine interleukins concentrations. Study was prospective. Statistics on the data were conducted with the Kolmogorov-Smirnov test. Significance level: p < 0.05. RESULTS: Concentrations of IL-6 and IL-18 were elevated in the IUGR group in a statistically significant manner in comparison to the control group. CONCLUSIONS: An elevated level of IL-6 and IL-18 in the IUGR group, comparing to control group, signifies the existence of inflammation in the process of developing IUGR, therefore, screening tests estimating levels of interleukins as IL-6 and IL-18 might be clinically useful in predicting the occurrence of IUGR and help preventing it.


Assuntos
Retardo do Crescimento Fetal/sangue , Recém-Nascido Pequeno para a Idade Gestacional/sangue , Interleucina-18/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Índice de Apgar , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Gravidez , Complicações Infecciosas na Gravidez/sangue , Nascimento a Termo
13.
Folia Histochem Cytobiol ; 50(3): 427-31, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-23042274

RESUMO

The immunogold technique with anti-diacylglycerol acyltransferase 2 (DGAT2) antibody revealed in A. thaliana embryo and root meristematic cells gold particles manifesting the presence of DGAT2 in ER as well as in lipid bodies. This being so, lipid synthesis could take place both in ER and in the lipid bodies. The presence of microtubules around the lipid bodies was evidenced under transmission EM. Detection of tubulin around the lipid bodies using the immunogold technique with anti-a-tubulin is in agreement with the above observations. Connection of lipid bodies with microtubules was also detected by us in other plants where they probably participated in lipid synthesis. A similar phenomenon may take place in A. thaliana.


Assuntos
Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/ultraestrutura , Arabidopsis/enzimologia , Arabidopsis/ultraestrutura , Diacilglicerol O-Aciltransferase/metabolismo , Diacilglicerol O-Aciltransferase/ultraestrutura , Lipídeos/química , Microtúbulos/metabolismo , Arabidopsis/citologia , Arabidopsis/embriologia , Imuno-Histoquímica , Microtúbulos/efeitos dos fármacos , Microtúbulos/ultraestrutura , Paclitaxel/farmacologia , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/ultraestrutura , Sementes/citologia , Sementes/efeitos dos fármacos , Sementes/enzimologia , Sementes/ultraestrutura
14.
Cell Biol Int ; 36(5): 455-62, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22295975

RESUMO

Lipid bodies present in lipotubuloids of Ornithogalum umbellatum ovary epidermis take the form of a lens between leaflets of ER (endoplasmic reticulum) membrane filled with a highly osmiophilic substance. The two enzymes, DGAT1 [DAG (diacylglycerol) acyltransferase 1] and DGAT2 (DAG acyltransferase 2), involved in this process are synthesized on rough ER and localized in the ER near a monolayer surrounding entities like lipid bodies. After reaching the appropriate size, newly formed lipid bodies transform into mature spherical lipid bodies filled with less osmiophilic content. They appear to be surrounded by a half-unit membrane, with numerous microtubules running adjacently in different directions. The ER, no longer continuous with lipid bodies, makes contact with them through microtubules. At this stage, lipid synthesis takes place at the periphery of lipid bodies. This presumption, and a hypothesis that microtubules are involved in lipid synthesis delivering necessary components to lipid bodies, is based on strong arguments: (i) silver grains first appear over microtubules after a short [3H]palmitic acid incubation and before they are observed over lipid bodies; (ii) blockade of [3H]palmitic acid incorporation into lipotubuloids by propyzamide, an inhibitor of microtubule function; and (iii) the presence of gold grains above the microtubules after DGAT1 and DGAT2 reactions, as also near microtubules after an immunogold method that identifies phospholipase D1.


Assuntos
Lipídeos/biossíntese , Microtúbulos/metabolismo , Ornithogalum/metabolismo , Benzamidas/farmacologia , Diacilglicerol O-Aciltransferase/metabolismo , Retículo Endoplasmático/metabolismo , Flores/metabolismo , Corpos de Inclusão/metabolismo , Lipogênese , Microtúbulos/efeitos dos fármacos , Ornithogalum/enzimologia , Fosfolipase D/metabolismo
15.
Folia Histochem Cytobiol ; 49(2): 285-90, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21744330

RESUMO

Lipotubuloids, structures containing lipid bodies and microtubules, are described in ovary epidermal cells of Ornithogalum umbellatum. Microtubules of lipotubuloids can be fixed in electron microscope fixative containing only buffered OsO(4) or in glutaraldehyde with OsO(4) post-fixation, or in a mixture of OsO(4) and glutaraldehyde. None of these substances fixes cortical microtubules of ovary epidermis of this plant which is characterized by dynamic longitudinal growth. However, cortical microtubules can be fixed with cold methanol according immunocytological methods with the use of ß-tubulin antibodies and fluorescein. The existence of cortical microtubules has also been evidenced by EM observations solely after the use of taxol, microtubule stabilizer, and fixation in a glutaraldehyde/OsO(4) mixture. These microtubules mostly lie transversely, sometimes obliquely, and rarely parallel to the cell axis. Staining, using Ruthenium Red and silver hexamine, has revealed that lipotubuloid microtubules surface is covered with polysaccharides. The presumption has been made that the presence of a polysaccharide layer enhances the stability of lipotubuloid microtubules.


Assuntos
Flores/citologia , Lipídeos/química , Microtúbulos/metabolismo , Ornithogalum/citologia , Epiderme Vegetal/citologia , Flores/efeitos dos fármacos , Flores/ultraestrutura , Microtúbulos/efeitos dos fármacos , Microtúbulos/ultraestrutura , Ornithogalum/efeitos dos fármacos , Ornithogalum/ultraestrutura , Paclitaxel/farmacologia , Epiderme Vegetal/efeitos dos fármacos , Epiderme Vegetal/ultraestrutura , Polissacarídeos/metabolismo
16.
Cell Biol Int ; 33(12): 1245-52, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19732846

RESUMO

Microtubules in lipotubuloids of the Ornithogalum umbellatum stipule epidermis cells change their diameters depending on the motion of the cytoplasmic domains rich in microtubules and lipid bodies. Microtubules fixed during rotary and progressive motion of the lipotubuloids composed of the same number of protofilaments fall into two populations - wide (43-58 nm) and narrow (24-39 nm) in size. Following blockage of the motion with 2,4-dinitrophenol (DNP), the range of this diversity is smaller, microtubules become a medium-sized population (34-48 nm). When DNP is removed and the motion reactivated, 2 populations of microtubules reappear. Analysis of the structure of the microtubule wall revealed that changes in the microtubule diameters resulted from varying distances between the adjacent protofilaments, and stretching and compression of tubulin subunits in the protofilaments. A supposition has been put forward that the changes in the sizes of O. umbellatum microtubule diameters: 1) are connected with the interactions between microtubules and actin microfilaments lying along these microtubules; 2) can be the driving force of the rotary motion of lipotubuloids.


Assuntos
Estruturas Citoplasmáticas/química , Estruturas Citoplasmáticas/fisiologia , Estruturas Citoplasmáticas/ultraestrutura , Microtúbulos/química , Ornithogalum/ultraestrutura , Epiderme Vegetal/ultraestrutura , Tubulina (Proteína)/química , Citoesqueleto de Actina/química , Actinas , Dimerização , Lipídeos/química , Microscopia Eletrônica de Transmissão , Microtúbulos/ultraestrutura , Ornithogalum/química , Epiderme Vegetal/química , Estrutura Quaternária de Proteína , Rotação , Tubulina (Proteína)/ultraestrutura
17.
Biol Reprod ; 80(3): 572-80, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19074004

RESUMO

During spermiogenesis of an alga Chara vulgaris, which in many aspects resembles that of animals, histones are replaced by protamine-type proteins. Our earlier immunocytochemical studies showed that this replacement started during the short stage V of spermiogenesis, when electronograms revealed an extensive system of cisternae and vesicles of endoplasmic reticulum (ER). The present studies revealed at stage V intensive incorporation of labeled (3)H-arginine and (3)H-lysine quickly translocating into a nucleus visualized with pulse-chase autoradiography of semithin sections. The immunogold technique with the use of the antibodies to protamine-type proteins isolated from Chara tomentosa show that both ER cisternae and vesicles are labeled with gold grains, which are absent from the spermatids not treated with the antibodies; thus, the ER is probably the site of the protamine-type protein synthesis. These proteins then are translocated to a nucleus through ER channels connected with the nuclear envelope, as suggested by gold labeling of an inner membrane of the nuclear envelope adjacent to condensed chromatin. The above results correspond with those of other authors showing that in animals, protamines bind with lamin B receptors localized in the inner membrane of the nuclear envelope. A hypothesis has been put forward that during Chara spermiogenesis the inner membrane of the nuclear envelope invaginates into a nucleus together with protamine-type proteins, which become separated from the membrane and penetrate into chromatin.


Assuntos
Proteínas de Algas/metabolismo , Núcleo Celular/metabolismo , Chara/metabolismo , Retículo Endoplasmático/metabolismo , Gametogênese/fisiologia , Protaminas/metabolismo , Biossíntese de Proteínas/fisiologia , Arginina/metabolismo , Transporte Biológico/fisiologia , Chara/citologia , Chara/ultraestrutura , Retículo Endoplasmático/ultraestrutura , Células Germinativas/citologia , Células Germinativas/metabolismo , Células Germinativas/ultraestrutura , Imuno-Histoquímica , Lisina/metabolismo , Membrana Nuclear/metabolismo , Membrana Nuclear/ultraestrutura , Receptores Citoplasmáticos e Nucleares/metabolismo , Trítio , Receptor de Lamina B
18.
Ginekol Pol ; 79(1): 17-22, 2008 Jan.
Artigo em Polonês | MEDLINE | ID: mdl-18510045

RESUMO

OBJECTIVES: to determine the relationship between the initial nucleated red blood cells (nRBC) count during the first 12 hours after birth and inborn infection in neonates. MATERIALS AND METHODS: The retrospective study comprised of 306 neonates born in the Department of Perinatology of the I Chair of Gynaecology and Obstetrics in Lódz, Poland, in the years 2002-2007, among whom the nucleated red blood cells count were calculated within the first 12 hours after birth. Two categories of nRBC count: the normal and the elevated value, were statistically elaborated by a Mann-Whitney test and a chi-square test with two clinical outcome categories: the presence and the absence of inborn infection in the analyzed neonates. Statistical significance was indicated by p value lower than 0,05. RESULTS: Among 306 newborns, there were 127 mature neonates (41.5%) and 179 prematures (58.5%). The mean of the initial nRBC count in the analyzed newborn population was 40, 15. The mean of the nRBC count in the infected neonates was three times higher (52.56) than the mean of the nRBC count in newborns without inborn infection (16.76) - (p=0.00001). Inborn neonatal infection concerned a vast majority of cases with an elevated value of the nRBC count (86.4%), but in 13.6%, inborn infection was not observed. Among the cases with a normal nRBC count, the presence and the absence of inborn infection was diagnosed in about 50% of the analyzed babies (50.83% vs 49.17%). The elevated value of the nRBC count in infected neonates concerned mainly premature babies, rather than mature neonates, and similarly in neonates with a lower Apgar score than in babies born in good condition. CONCLUSIONS: 1. The positive association between elevated initial nucleated red blood cells count after birth and inborn infection in newborns has been revealed. 2. An elevated nucleated red blood cells count may be an auxiliary, early indicator for inborn infection in neonates. 3. Prematurity and perinatal asphyxia favour the elevation of a nucleated red blood cells count in cases with inborn infection.


Assuntos
Eritroblastos/patologia , Doenças do Recém-Nascido/sangue , Doenças do Recém-Nascido/diagnóstico , Recém-Nascido Prematuro/sangue , Infecções/sangue , Infecções/congênito , Biomarcadores/sangue , Contagem de Eritrócitos , Feminino , Humanos , Recém-Nascido/sangue , Masculino , Polônia/epidemiologia , Valor Preditivo dos Testes , Síndrome do Desconforto Respiratório do Recém-Nascido/sangue , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Estudos Retrospectivos , Estatísticas não Paramétricas
19.
Biol Reprod ; 78(4): 577-85, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18199881

RESUMO

Spermiogenesis in Chara vulgaris and in animals share many common features, including exchange of nucleohistones into nucleoprotamines, remodeling and extreme condensation of chromatin, formation of flagellae and of microtubule manchette, and decrease in cytoplasm volume. In C. vulgaris, spermiogenesis is not preceded by meiosis since this alga is a haplobiont. In the present work we showed that in early spermiogenesis characterized by a significant metabolic activity of spermatids, the inhibitors of proteasomes did not visibly change their ultrastructure but significantly prolonged this process. At late stages of spermiogenesis, MG-132 and epoxomicin dramatically changed the structure of nuclei: regular fibrillar and lamellar structure of chromatin was disturbed and clusters of grains corresponding to aggresomes appeared, but the nucleus shape and cytoplasm structure were the same as in the controls. Immunocytochemical studies revealed that these inhibitors blocked disappearance of histones from nuclei while the structures corresponding to aggresomes were clusters of undegraded ubiquitinated histones, since they gave positive immunosignals indicating the presence of ubiquitin and histones.


Assuntos
Chara/fisiologia , Imuno-Histoquímica , Complexo de Endopeptidases do Proteassoma/fisiologia , Inibidores de Proteassoma , Espermatogênese/fisiologia , Ubiquitina/fisiologia , Núcleo Celular/química , Chara/ultraestrutura , Citoplasma/química , Histonas/análise , Microscopia Eletrônica , Complexo de Endopeptidases do Proteassoma/ultraestrutura , Ubiquitina/análise , Ubiquitina/ultraestrutura
20.
J Exp Bot ; 58(8): 2023-31, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17452750

RESUMO

Cytophotometry of individual nuclei was used to examine the level of endoreduplication in epidermal cells from the upper and lower parts of the ovary during Ornithogalum umbellatum flower and fruit development. An increase in DNA content from 2-4C to 2-8C in both parts of the ovary was observed, while the epidermal cell surface area grew about 6-fold and 15-fold in the lower and upper parts of the ovary, respectively. However, the correlation between mean epidermal cell size and ploidy was distinct during epidermis growth. Lipotubuloids became bigger in the upper than in the lower part during ovary and fruit development. In addition, more dynamic growth of the epidermal cells of the upper than of the lower part of the ovary was connected to the higher content of gibberellic acid. A hypothesis has been put forward that the role of DNA endoreduplication in epidermal cell growth was modulated by the function of lipotubuloids and the gradient of gibberellin.


Assuntos
Crescimento Celular , Replicação do DNA/fisiologia , Frutas/crescimento & desenvolvimento , Giberelinas/fisiologia , Ornithogalum/crescimento & desenvolvimento , Flores/citologia , Flores/crescimento & desenvolvimento , Flores/fisiologia , Frutas/citologia , Frutas/genética , Giberelinas/metabolismo , Ornithogalum/citologia , Ornithogalum/genética , Poliploidia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA