36 research outputs found
Genomic and environmental factors influence Wolbachia-Drosophila symbiosis
Intracellular, vertically transmitted bacteria form complex and intimate
relationships with their hosts. Wolbachia, maternally transmitted α-
proteobacteria, live within the cells of numerous arthropod species.
Wolbachia are famous master manipulators of insect reproduction: to
favour their own spread they can induce male killing, parthenogenesis or
cytoplasmic incompatibility. Wolbachia can also protect various insects
from pathogens, which makes them a promising tool for the control of
vector-borne diseases. Mosquitoes with Wolbachia have already been
released in the wild to eliminate dengue. Yet, how Wolbachia manipulate
their hosts remains largely unknown.(...)Fundação para a Ciência e a Tecnologi
The Role of Rac1 in the Epidermis and in the Hair Follicle
Rac1 is a ubiquitously expressed member of the Rho family of small GTPases, which acts as a molecular switch by shuttling in a highly regulated manner between an active (GTP-bound) and an inactive (GDP-bound) state. Different signalling pathways, which involve integrins, growth factor receptors, cadherins as well as other Rho GTPases, can induce Rac1 activation. Only in the GTP bound form, Rac1 can associate with different effector molecules to initiate cellular responses.
Initially described as an important regulator of the actin cytoskeleton, Rac1 was later found to be also involved in the modulation of other processes such as cell adhesion, proliferation, survival, differentiation and migration. In epithelial cells, Rac1 was shown to regulate the formation and maintenance of cadherin dependent cell cell contacts, which are essential for the establishment of the polarized cell morphology.
Before this project was initiated, almost all knowledge about the function of Rac1 was based on in vitro studies. As constitutive deletion of the murine rac1 gene leads to early embryonic lethality, mice allowing for a conditional inactivation of the rac1 gene were generated in this study to enable the analysis of the function of Rac1 in selected tissues. To investigate the role of Rac1 in the epidermis and hair follicles and to determine its function in the establishment and maintenance of cell cell contacts between epithelial cells in vivo, mice with a keratinocyte-restricted ablation of the rac1 gene were generated and analyzed.
The results obtained in this study showed that the absence of Rac1 in the murine epidermis leads to a progressive hair loss but surprisingly has no effect on the maintenance of the epidermis. The hair loss is caused by the inability of hair follicle keratinocytes to maintain their differentiation state, which leads to the phagocytic removal of the non permanent parts of the hair follicles by infiltrating macrophages. In contrast, differentiation and proliferation of epidermal keratinocytes as well as the formation and maintenance of cell-cell and cell-matrix contacts, and the deposition of the basement membrane in the epidermis are not affected by the loss of Rac1. Biochemical analysis of epidermal lysates demonstrated that the absence of epidermal defects in vivo is not a result of compensatory upregulation of closely related members of the Rho family of GTPases, further indicating that the function of Rac1 in epithelial cells in vivo is limited. Also, the analysis of the formation of the embryoid bodies from Rac1-deficient embryonic stem cells showed that the presence of Rac1 is not required for the establishment of cell cell contacts during differentiation of the polarized primitive ectoderm and for the formation of epithelial sheets, supporting the conclusion that the function of Rac1 in the regulation of cell cell adhesion between epithelial cells is dispensable.
However, the re epithelialization after wounding was impaired in the mutant epidermis, demonstrating that Rac1 plays an important role in pathological conditions. The delayed wound closure in the absence of Rac1 is caused by impaired cell migration and proliferation of neo epidermal keratinocytes.
Another interesting finding of this study was the observation that, in contrast to the steady state in vivo situation, isolated Rac1 deficent primary keratinocytes display severe defects in cell culture, which lead to their detachment from the matrix. While the initial adhesion is only mildly affected by the lack of Rac1, mutant keratinocytes are unable to spread, show an impaired organization of the actin cytoskeleton and fail to form mature focal adhesions.
The differences between in vivo and in vitro effects resulting from the inactivation of the rac1 gene indicate that the function of Rac1 in epithelial cells depends on the complexity of the cellular system and emphasize the importance of performing in vivo studies to fully understand its role.
Taken together, the data presented in this study show that Rac1 plays an important role in the maintenance of hair follicles and during epidermal wound healing, but that it is not essential for the homeostasis of the epidermis in physiological conditions and for the formation and maintenance of cell cell contacts between epithelial cells in vivo
Profilaktyka i wczesna interwencja w jąkaniu u małych dzieci
Early intervention in young children who stutter is indicated as an effective approach
by research and practice in the field. However, there is a need for the child to be supported
by her/his entire environment. The article discusses the forms of action that can
and should be taken by parents, speech-language therapists, teachers, and educators. The
article emphasizes the importance of an adequate relationship that should be established
between these persons. It is pointed out how important they are for success in prevention
and early intervention of stuttering in young children — both individually and in groups
interacting with each other. Referring to the decision streams based on chronic stuttering
risk factors by P. Zebrowski (1997), the authors also present some early intervention
strategies that can be used by SLT’s
Investigating the roles of loneliness and clinician- and self-rated depressive symptoms in predicting the subjective quality of life among people with psychosis
Purpose: to examine the roles of loneliness and clinician- and self-rated depressive symptoms as predictors of the subjective quality of life (QoL) in psychosis. Methods: this cross-sectional study was conducted on a sample of 207 patients diagnosed with psychotic disorders. They were assessed with self-reported measures of QoL, loneliness and depression and with clinician-rated measures of depression and overall psychopathology. Multiple indicators multiple causes (MIMIC) modeling was used to analyze the data. Results: both loneliness and depression turned out to be independent predictors of impaired QoL. However, once loneliness was accounted for, the effect of depression on QoL was markedly reduced and the effect of loneliness proved to be visibly larger. Self-rated depression was found to be more strongly associated with QoL than clinician-rated depression. Each type of depression measure explained a unique amount of variance in QoL. Depression moderated the relationship between loneliness and QoL in such a way that the negative effect of loneliness on QoL weakened with the increasing intensity of depressive symptoms. Conclusions: therapeutic programs aiming to enhance the QoL of people with psychotic disorders should incorporate interventions targeting both loneliness and depression and need to be tailored to the clinical status of patients. The emphasis on alleviating loneliness should be placed first of all in the case of those with low levels of depression, among whom the negative impact of loneliness on QoL is especially strong. Researchers should be aware that the method chosen for assessing depressive symptoms in models predicting QoL in psychosis matters
The evaluation of the impact of anti-stigma training led by "experts by experience’ on participants" attitudes towards persons with mental illness
Aim. The purpose of this study was to evaluate the impact of anti-stigma training led by people who had previously experienced mental health crises (i.e., ‛experts by experience’) on various aspects of participants’ attitudes towards the people with mental illness. Method. The three-hour workshops were attended by 185 people; the training was held in 17 groups, with 3-19 people in each (11 on average). Almost half of the participants (45.4%) were employees of the mentalhealth care system. The participants were asked to fill out a set of questionnaires immediately before and after the training, which evaluated the following aspects of their attitudes: social distance, stigmatizing attributions, beliefs about self-determination/ability to attain important life goals by people with mental illness, and also beliefs about the social value of people with mental illness. The respondents were asked to complete the same set of questionnaires again online a month and six months after the training. The data were analyzed based on a piecewise latent trajectory model. Results. Out of the 185 people who participated in the workshops, 115 (62.2%) filled out the questionnaires a month after, and 87 (47.0%) six months after the training. The analyses showed an improvement in all four measures of attitudes expressed directly after the training. In three out of the four examined aspects of attitudes (intensity of social distance, stigmatizing attributions and beliefs about self-determination of people with mental illness) the positive impact of the training continued after six months. Conclusions. The results provide preliminary empirical evidence that the structured antistigma intervention under evaluation, using the elements of education and interpersonal contact can be an effective tool for improving social attitudes towards people with mental illness
Essential and distinct roles for cdc42 and rac1 in the regulation of Schwann cell biology during peripheral nervous system development
During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue-specific conditional gene targeting to show that members of the Rho GTPases, cdc42 and rac1, have different and essential roles in axon sorting by Schwann cells. Our results indicate that although cdc42 is required for normal Schwann cell proliferation, rac1 regulates Schwann cell process extension and stabilization, allowing efficient radial sorting of axon bundles
Determinants of Psychosocial Difficulties Experienced by Persons with Brain Disorders: Towards a 'Horizontal Epidemiology' Approach
Background Persons with brain disorders experience significant psychosocial difficulties (PSD) in daily life, e.g. problems with managing daily routine or emotional lability, and the level of the PSD depends on social, physical and political environments, and psychologic-personal determinants. Our objective is to determine a brief set of environmental and psychologic-personal factors that are shared determinants of PSD among persons with different brain disorders. Methods Cross-sectional study, convenience sample of persons with either dementia, stroke, multiple sclerosis, epilepsy, migraine, depression, schizophrenia, substance dependence or Parkinson's disease. Random forest regression and classical linear regression were used in the analyses. Results 722 subjects were interviewed in four European countries. The brief set of determinants encompasses presence of comorbidities, health status appraisal, stressful life events, personality changes, adaptation, self-esteem, self-worth, built environment, weather, and health problems in the family. Conclusions The identified brief set of common determinants of PSD can be used to support the implementation of cross-cutting interventions, social actions and policy tools to lower PSD experienced by persons with brain disorders. This set complements a recently proposed reliable and valid direct metric of PSD for brain disorders called PARADISE24
Understanding the impact of brain disorders: Towards a 'horizontal epidemiology' of psychosocial difficulties and their determinants
Objective
To test the hypothesis of ‘horizontal epidemiology’, i.e. that psychosocial difficulties (PSDs),
such as sleep disturbances, emotional instability and difficulties in personal interactions,
and their environmental determinants are experienced in common across neurological and
psychiatric disorders, together called brain disorders.
Study Design
A multi-method study involving systematic literature reviews, content analysis of patientreported
outcomes and outcome instruments, clinical input and a qualitative study was
carried out to generate a pool of PSD and environmental determinants relevant for nine different
brain disorders, namely epilepsy, migraine, multiple sclerosis, Parkinson’s disease,
stroke, dementia, depression, schizophrenia and substance dependency. Information from
these sources was harmonized and compiled, and after feedback from external experts, a
data collection protocol including PSD and determinants common across these nine disorders
was developed. This protocol was implemented as an interview in a cross-sectional
Objective
To test the hypothesis of ‘horizontal epidemiology’, i.e. that psychosocial difficulties (PSDs),
such as sleep disturbances, emotional instability and difficulties in personal interactions,
and their environmental determinants are experienced in common across neurological and
psychiatric disorders, together called brain disorders.
Study Design
A multi-method study involving systematic literature reviews, content analysis of patientreported
outcomes and outcome instruments, clinical input and a qualitative study was
carried out to generate a pool of PSD and environmental determinants relevant for nine different
brain disorders, namely epilepsy, migraine, multiple sclerosis, Parkinson’s disease,
stroke, dementia, depression, schizophrenia and substance dependency. Information from
these sources was harmonized and compiled, and after feedback from external experts, a
data collection protocol including PSD and determinants common across these nine disorders
was developed. This protocol was implemented as an interview in a cross-sectionalThe PARADISE project is supported by the
Coordination Theme 1 (Health) of the European
Community’s FP7, Grant Agreement No. HEALTHF2-
2009-241572
The castle in Sucha Beskidzka - problems of conservation and development of the historic mansion
Przedmiotem pracy jest analiza zagospodarowania i ochrony konserwatorskiej zespołu zamkowo-parkowego w Suchej Beskidzkiej na przestrzeni lat. W tekście przedstawiona została również historia zamku od czasu jego powstania w XVI wieku do chwili obecnej. Opracowanie, na przykładzie suskiego założenia, porusza zagadnienia dotyczące zabytkowych rezydencji w całej Polsce, które na skutek przeprowadzonej w 1947 roku reformy rolnej, pozbawione zostały swych zbiorów. Aktualnie, pomimo najczęściej dobrego stanu zachowania tych zabytków, istnieje duży problem z ochroną ich dziedzictwa. Praca zwraca uwagę na możliwe w obecnych warunkach rozwiązania kwestii zaistnienia zamku w kulturze oraz w świadomości społecznej.The subject of the work consists on the analysis of development and conservational protection of the castle-park complex in Sucha Beskidzka over the years. Text also shows the history of the castle from the time when it was built in 16th century to present times. Elaboration, on the example of complex in Sucha, brings up the issue related to the historic mansions throughout Poland which due to the agrarian reform pursued in 1947 were deprived of their collections. Currently, despite usually good condition of these historical buildings, there exists a big problem with preserving their heritage. Work draws attention to possible in the present circumstances solutions of resolving the issue of coming into being the existence of the castle in the culture and in the social awareness