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1.
J Rheumatol ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009386

RESUMO

Two years after its inception, Young Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (Y-GRAPPA) has established itself as a productive network for junior investigators and clinicians. The group's achievements in the last year include updating the educational GRAPPA slide library, the "Bring a Derm" campaign to expand the GRAPPA community to include more dermatologists, and the publication of multiple "Do Not Miss" newsletters covering the highlights on PsDs from the major international conferences (American Academy of Dermatology [AAD] Annual Meeting, European Alliance of Associations for Rheumatology [EULAR] Congress, European Academy of Dermatology and Venereology [EADV] Congress, and American College of Rheumatology [ACR] Convergence).

2.
Int J Mol Sci ; 23(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35328665

RESUMO

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus endemic to Africa and the Arabian Peninsula, which causes diseases in humans and livestock. C-type lectin receptors (CLRs) represent a superfamily of pattern recognition receptors that were reported to interact with diverse viruses and contribute to antiviral immune responses but may also act as attachment factors or entry receptors in diverse species. Human DC-SIGN and L-SIGN are known to interact with RVFV and to facilitate viral host cell entry, but the roles of further host and vector CLRs are still unknown. In this study, we present a CLR-Fc fusion protein library to screen RVFV-CLR interaction in a cross-species approach and identified novel murine, ovine, and Aedes aegypti RVFV candidate receptors. Furthermore, cross-species CLR binding studies enabled observations of the differences and similarities in binding preferences of RVFV between mammalian CLR homologues, as well as more distant vector/host CLRs.


Assuntos
Aedes , Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Humanos , Lectinas Tipo C/genética , Mamíferos , Camundongos , Mosquitos Vetores/genética , Ovinos
3.
Hum Mol Genet ; 26(19): 3736-3748, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28934386

RESUMO

Myotubularins (MTMs) are active or dead phosphoinositides phosphatases defining a large protein family conserved through evolution and implicated in different neuromuscular diseases. Loss-of-function mutations in MTM1 cause the severe congenital myopathy called myotubular myopathy (or X-linked centronuclear myopathy) while mutations in the MTM1-related protein MTMR2 cause a recessive Charcot-Marie-Tooth peripheral neuropathy. Here we aimed to determine the functional specificity and redundancy of MTM1 and MTMR2, and to assess their abilities to compensate for a potential therapeutic strategy. Using molecular investigations and heterologous expression of human MTMs in yeast cells and in Mtm1 knockout mice, we characterized several naturally occurring MTMR2 isoforms with different activities. We identified the N-terminal domain as responsible for functional differences between MTM1 and MTMR2. An N-terminal extension observed in MTMR2 is absent in MTM1, and only the short MTMR2 isoform lacking this N-terminal extension behaved similarly to MTM1 in yeast and mice. Moreover, adeno-associated virus-mediated exogenous expression of several MTMR2 isoforms ameliorates the myopathic phenotype owing to MTM1 loss, with increased muscle force, reduced myofiber atrophy, and reduction of the intracellular disorganization hallmarks associated with myotubular myopathy. Noteworthy, the short MTMR2 isoform provided a better rescue when compared with the long MTMR2 isoform. In conclusion, these results point to the molecular basis for MTMs functional specificity. They also provide the proof-of-concept that expression of the neuropathy-associated MTMR2 gene improves the MTM1-associated myopathy, thus identifying MTMR2 as a novel therapeutic target for myotubular myopathy.


Assuntos
Miopatias Congênitas Estruturais/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Animais , Humanos , Masculino , Camundongos , Camundongos Knockout , Mutação , Miopatias Congênitas Estruturais/enzimologia , Miopatias Congênitas Estruturais/metabolismo , Fenótipo , Domínios Proteicos , Isoformas de Proteínas , Proteínas Tirosina Fosfatases não Receptoras/genética
4.
Int J Mol Sci ; 18(3)2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28294977

RESUMO

Phosphoinositides are lipids involved in the vesicular transport of proteins and lipids between the different compartments of eukaryotic cells. They act by recruiting and/or activating effector proteins and thus are involved in regulating various cellular functions, such as vesicular budding, membrane fusion and cytoskeleton dynamics. Although detected in small concentrations in membranes, their role is essential to cell function, since imbalance in their concentrations is a hallmark of many cancers. Their synthesis involves phosphorylating/dephosphorylating positions D3, D4 and/or D5 of their inositol ring by specific lipid kinases and phosphatases. This process is tightly regulated and specific to the different intracellular membranes. Most enzymes involved in phosphoinositide synthesis are conserved between yeast and human, and their loss of function leads to severe diseases (cancer, myopathy, neuropathy and ciliopathy).


Assuntos
Membrana Celular/metabolismo , Metabolismo dos Lipídeos , Fosfatidilinositóis/metabolismo , Transdução de Sinais , Actinas/metabolismo , Animais , Autofagia , Transporte Biológico , Endocitose , Endossomos/metabolismo , Humanos , Lisossomos/metabolismo , Redes e Vias Metabólicas , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfolipídeos/metabolismo , Esteróis/metabolismo
5.
PLoS Genet ; 8(10): e1002965, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23071445

RESUMO

Myotubularin MTM1 is a phosphoinositide (PPIn) 3-phosphatase mutated in X-linked centronuclear myopathy (XLCNM; myotubular myopathy). We investigated the involvement of MTM1 enzymatic activity on XLCNM phenotypes. Exogenous expression of human MTM1 in yeast resulted in vacuolar enlargement, as a consequence of its phosphatase activity. Expression of mutants from patients with different clinical progression and determination of PtdIns3P and PtdIns5P cellular levels confirmed the link between vacuolar morphology and MTM1 phosphatase activity, and showed that some disease mutants retain phosphatase activity. Viral gene transfer of phosphatase-dead myotubularin mutants (MTM1(C375S) and MTM1(S376N)) significantly improved most histological signs of XLCNM displayed by a Mtm1-null mouse, at similar levels as wild-type MTM1. Moreover, the MTM1(C375S) mutant improved muscle performance and restored the localization of nuclei, triad alignment, and the desmin intermediate filament network, while it did not normalize PtdIns3P levels, supporting phosphatase-independent roles of MTM1 in maintaining normal muscle performance and organelle positioning in skeletal muscle. Among the different XLCNM signs investigated, we identified only triad shape and fiber size distribution as being partially dependent on MTM1 phosphatase activity. In conclusion, this work uncovers MTM1 roles in the structural organization of muscle fibers that are independent of its enzymatic activity. This underlines that removal of enzymes should be used with care to conclude on the physiological importance of their activity.


Assuntos
Miopatias Congênitas Estruturais/genética , Fenótipo , Proteínas Tirosina Fosfatases não Receptoras/genética , Animais , Desmina/metabolismo , Modelos Animais de Doenças , Ativação Enzimática/genética , Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Knockout , Força Muscular/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Mutação , Miopatias Congênitas Estruturais/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
6.
Int J Mol Sci ; 16(1): 1509-25, 2015 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-25584613

RESUMO

The yeast Saccharomyces cerevisiae is one of the best characterized eukaryotic models. The secretory pathway was the first trafficking pathway clearly understood mainly thanks to the work done in the laboratory of Randy Schekman in the 1980s. They have isolated yeast sec mutants unable to secrete an extracellular enzyme and these SEC genes were identified as encoding key effectors of the secretory machinery. For this work, the 2013 Nobel Prize in Physiology and Medicine has been awarded to Randy Schekman; the prize is shared with James Rothman and Thomas Südhof. Here, we present the different trafficking pathways of yeast S. cerevisiae. At the Golgi apparatus newly synthesized proteins are sorted between those transported to the plasma membrane (PM), or the external medium, via the exocytosis or secretory pathway (SEC), and those targeted to the vacuole either through endosomes (vacuolar protein sorting or VPS pathway) or directly (alkaline phosphatase or ALP pathway). Plasma membrane proteins can be internalized by endocytosis (END) and transported to endosomes where they are sorted between those targeted for vacuolar degradation and those redirected to the Golgi (recycling or RCY pathway). Studies in yeast S. cerevisiae allowed the identification of most of the known effectors, protein complexes, and trafficking pathways in eukaryotic cells, and most of them are conserved among eukaryotes.


Assuntos
Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Membrana Celular/metabolismo , Endocitose , Endossomos/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Vesículas Secretórias/metabolismo
7.
Cell Calcium ; 111: 102717, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36931195

RESUMO

Our sensory environment is permeated by a diverse array of auditory and somatosensory stimuli. The pairing of acoustic signals with concurrent or forthcoming tactile cues are abundant in everyday life and various survival contexts across species, thus deeming the ability to integrate sensory inputs arising from the combination of these stimuli as crucial. The corticothalamic system plays a critical role in orchestrating the construction, integration and distribution of the information extracted from these sensory modalities. In this mini-review, we provide a circuit-level description of the auditory corticothalamic pathway in conjunction with adjacent corticothalamic somatosensory projections. Although the extent of the functional interactions shared by these pathways is not entirely elucidated, activation of each of these systems appears to modulate sensory perception in the complementary domain. Several specific issues are reviewed. Under certain environmental noise conditions, the spectral information of a sound could induce modulations in nociception and even induce analgesia. We begin by discussing recent findings by Zhou et al. (2022) implicating the corticothalamic system in mediating sound-induced analgesia. Next, we describe relevant components of the corticothalamic pathway's functional organization. Additionally, we describe an emerging body of literature pointing to intrathalamic circuitry being optimal for controlling and selecting sensory signals across modalities, with the thalamic reticular nucleus being a candidate mechanism for directing cross-modal interactions. Finally, Ca2+ bursting in thalamic neurons evoked by the thalamic reticular nucleus is explored.


Assuntos
Analgesia , Tálamo , Tálamo/metabolismo , Neurônios/fisiologia
8.
Front Plant Sci ; 14: 1165269, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37600208

RESUMO

Worldwide, Ascochyta blight is caused by a complex of host-specific fungal pathogens, including Ascochyta pisi, Didymella pinodes, and Didymella pinodella. The application of foliar fungicides is often necessary for disease management, but a better understanding of pathogen prevalence, aggressiveness, and fungicide sensitivity is needed to optimize control. Leaf and stem samples were obtained from 56 field pea production fields in 14 counties in North Dakota from 2017 to 2020 and isolates were collected from lesions characteristic of Ascochyta blight. Based on fungal characteristics and sequencing the ITS1-5.8S-ITS2 region, 73% of isolates were confirmed to be D. pinodes (n = 177) and 27% were A. pisi (n = 65). Across pathogens, aggressiveness was similar among some isolates in greenhouse assays. The in vitro pyraclostrobin sensitivity of all D. pinodes isolates collected from 2017 to 2020 was lower than that of the three baseline isolates. Sensitivity of 91% of A. pisi isolates collected in 2019 and 2020 was lower than the sensitivity of two known sensitive isolates. Resistance factors (Rf) from mean EC50 values of pyraclostrobin baseline/known sensitive isolates to isolates collected from 2017 to 2020 ranged from 2 to 1,429 for D. pinodes and 1 to 209 for A. pisi. In vitro prothioconazole sensitivity of 91% of D. pinodes isolates collected from 2017 to 2020 was lower than the sensitivity of the baseline isolates and 98% of A. pisi isolates collected from 2019 to 2020 was lower than the sensitivity of the known sensitive isolates. Prothioconazole Rf ranged from 1 to 338 for D. pinodes and 1 to 127 for A. pisi. Based on in vitro results, 92% of D. pinodes and 98% of A. pisi isolates collected displayed reduced-sensitivity/resistance to both fungicides when compared to baseline/known sensitive isolates. Disease control under greenhouse conditions of both pathogens provided by both fungicides was significantly lower in isolates determined to be reduced-sensitive or resistant in in vitro assays when compared to sensitive. Results reported here reinforce growers desperate need of alternative fungicides and/or management tools to fight Ascochyta blight in North Dakota and neighboring regions.

9.
Hear Res ; 428: 108667, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36566642

RESUMO

The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess psychophysiology in humans and animals for almost a century in diverse fields such as schizophrenia, bipolar disorder, hearing loss, and tinnitus. Previously, SR waveforms have been ignored, or assessed with basic statistical techniques and/or simple template matching paradigms. This has led to considerable variability in SR studies from different laboratories, and species. In an effort to standardize SR assessment methods, we developed a machine learning algorithm and workflow to automatically classify SR waveforms in virtually any animal model including mice, rats, guinea pigs, and gerbils obtained with various paradigms and modalities from several laboratories. The universal features common to SR waveforms of various species and paradigms are examined and discussed in the context of each animal model. The procedure describes common results using the SR across species and how to fully implement the open-source R implementation. Since SR is widely used to investigate toxicological or pharmaceutical efficacy, a detailed and universal SR waveform classification protocol should be developed to aid in standardizing SR assessment procedures across different laboratories and species. This machine learning-based method will improve data reliability and translatability between labs that use the startle reflex paradigm.


Assuntos
Reflexo de Sobressalto , Zumbido , Humanos , Ratos , Camundongos , Animais , Cobaias , Reflexo de Sobressalto/fisiologia , Estimulação Acústica/métodos , Reprodutibilidade dos Testes , Modelos Animais de Doenças , Gerbillinae
10.
J Rheumatol ; 50(Suppl 2): 58-60, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37453733

RESUMO

Young-GRAPPA (Y-GRAPPA) was introduced at the 2021 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) annual meeting. Here we present the 1-year progress of Y-GRAPPA and future plans of this enthusiastic group of young clinicians and early career researchers interested in psoriasis and psoriatic arthritis.


Assuntos
Artrite Psoriásica , Dermatologia , Psoríase , Reumatologia , Humanos
11.
Microorganisms ; 10(1)2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35056627

RESUMO

Toxocara canis and Toxocara cati are globally occurring zoonotic roundworms of dogs and cats. Migration and persistence of Toxocara larvae in the central nervous system of paratenic hosts including humans may cause clinical signs of neurotoxocarosis (NT). As pathomechanisms of NT and host responses against Toxocara larvae are mostly unknown, whole-genome microarray transcription analysis was performed in cerebra and cerebella of experimentally infected C57Bl/6J mice as paratenic host model at days 14, 28, 70, 98, and 120 post-infection. Neuroinvasion of T. cati evoked 220 cerebral and 215 cerebellar differentially transcribed genes (DTGs), but no particular PANTHER (Protein ANalysis THrough Evolutionary Relationships) pathway was affected. In T. canis-infected mice, 1039 cerebral and 2073 cerebellar DTGs were identified. Statistically significant dysregulations occurred in various pathways, including cholesterol biosynthesis, apoptosis signaling, and the Slit/Robo mediated axon guidance as well as different pathways associated with the immune and defense response. Observed dysregulations of the cholesterol biosynthesis, as well as the Alzheimer disease-amyloid secretase pathway in conjunction with previous histopathological neurodegenerative findings, may promote the discussion of T. canis as a causative agent for dementia and/or Alzheimer's disease. Furthermore, results contribute to a deeper understanding of the largely unknown pathogenesis and host-parasite interactions during NT, and may provide the basis for prospective investigations evaluating pathogenic mechanisms or designing novel diagnostic and therapeutic approaches.

12.
J Rheumatol ; 49(6 Suppl 1): 37-39, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35232806

RESUMO

At the 2021 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) annual meeting, a separate group was created (Young-GRAPPA) to address the challenges of young researchers and physicians beginning their careers. This paper presents the initial organizational framework and different components and aims of this group. We were able to enroll over 50 young researchers as a result of this meeting.


Assuntos
Artrite Psoriásica , Dermatologia , Psoríase , Reumatologia , Artrite Psoriásica/diagnóstico , Humanos , Organizações
13.
Eur Rev Med Pharmacol Sci ; 25(18): 5781-5789, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34604969

RESUMO

OBJECTIVE: The aim of the present study was to systematically assess the value of contrast-enhanced ultrasound (CEUS) vs. conventional transthoracic ultrasound (TUS) in improving diagnostic accuracy of percutaneous needle biopsy (PTNB) for subpleural lung lesions. PATIENTS AND METHODS: 232 patients with subpleural lesions were 1:1 randomly assigned to a group were CEUS was performed (n=116, mean age=65.5±5.6, M=69) or not (n=116, mean age=66.0±5.3, M=70). For CEUS study was used an injection of 4.8 mL of SonoVue (Bracco, Italy). For PTNB was employed a Menghini-modified technique with a semi-automatic 18-gauge needle. RESULTS: The mean diameter of subpleural lesions was 2.85±0.7 cm in the CEUS+ group and 2.95±0.6cm in the CEUS- group. Only 3 lesions, 1 in the CEUS+ group and 2 in the CEUS- group measured >5 cm. CEUS showed no superiority in terms of diagnostic accuracy compared to conventional TUS (p=0.34). Similar results were obtained in the sub-analysis of lesions sized between 1-2 cm (p=1.00) and 2-5 cm (p=0.08). As the lesion size increased, the detection rate of necrosis in lesions increased by CEUS (from 8% to 31%). CEUS showed no superiority in terms of diagnostic accuracy in the sub-analysis of necrotic lesions at CECT (p=0.38). AUC values for both the groups assessed an excellent diagnostic yield for TUS-PTNB (≥0.80). CONCLUSIONS: CEUS study does not improve the diagnostic accuracy of TUS-guided PTNB for peripheral lung lesions <5 cm of diameter. Further studies evaluating CEUS guidance for larger (>5 cm) and necrotic lesions are needed prior that its potential can be clarified.


Assuntos
Biópsia por Agulha/métodos , Aumento da Imagem/métodos , Pneumopatias/diagnóstico por imagem , Pneumopatias/patologia , Pulmão/diagnóstico por imagem , Pulmão/patologia , Ultrassonografia/métodos , Idoso , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
14.
G Ital Med Lav Ergon ; 32(4): 422-5, 2010.
Artigo em Italiano | MEDLINE | ID: mdl-21086695

RESUMO

Communication is a process which enables groups and individuals to increase their control over determining health factors acting on people's lifestyles to promote health. Good communication is fundamental to the health sector in a globalized world, since it may influence national and local policies, health promotion campaigns and correct operational practices. Our study analyses four significant incidents related to instances of bad communication and covers questions which have produced rather incoherent results provoking unjustified alarm. It is therefore necessary to prescribe a way of approaching these issues which will firstly lead to a more careful analysis of the risk involved and therefore to make known correct public information. It is necessary to improve the skills of experts in prevention, to promote educational initiatives at school, universities and in workplaces always focussing more on interdisciplinarity and developing new ways of approaching problems concerning health and safety.


Assuntos
Comunicação , Doenças Profissionais/prevenção & controle , Saúde Ocupacional , Humanos
15.
G Ital Med Lav Ergon ; 32(4 Suppl): 421-5, 2010.
Artigo em Italiano | MEDLINE | ID: mdl-21438311

RESUMO

The agricultural activities have several issues in the management of safety and health of workers. The study of two ASL of Central Italy (VT and RMH) intended to check the risk conditions in order to highlight most critical points and define a prevention and surveillance plan. We moved in these directions: verification of workplaces and work practices; examination of machineries and equipment; active search of occupational diseases. We analyzed some peculiar aspects of the health surveillance of 75 workers such as risk from sun exposure, significantly underestimated by employers and competent doctors, despite sun exposure diseases are included in the list for which reporting is mandatory. Our study shows that a targeted campaign of prevention and control can lead to an improvement in safety management, on the other hand shows the necessity to bring occupational health physician to assess and manage also less valuated risks as the sun exposure.


Assuntos
Agricultura , Doenças Profissionais/prevenção & controle , Exposição Ocupacional/prevenção & controle , Saúde Ocupacional , Inquéritos Epidemiológicos , Humanos , Vigilância da População , Fatores de Risco
16.
Vet Immunol Immunopathol ; 224: 110047, 2020 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-32325253

RESUMO

C-type lectin receptors (CTLRs) are pattern recognition receptors which are important constituents of the innate immunity. However, their role has mostly been studied in humans and in mouse models. To bridge the knowledge gap concerning CTLRs of veterinary relevant species, a novel ovine CTLR hFc-fusion protein library which allows in vitro ligand identification and pathogen binding studies has been established. Its utility was tested with known ligands of corresponding murine CTLRs in ELISA- and flow cytometry based binding studies. The ovine CTLR-hFc library was subsequently used in a proof-of-principle pathogen binding study with the ruminant pathogen Mycoplasma mycoides subsp. capri. Some ovine CTLRs, such as Dendritic Cell Immunoreceptor (DCIR, Clec4a), Macrophage C-Type Lectin (MCL, Clec4d) and Myeloid Inhibitory C-Type Lectin-Like Receptor (MICL, Clec12a) were identified as possible candidate receptors whose role in Mycoplasma recognition can now be unraveled in further studies. This study thus shows the utility of this novel ovine CTLR-hFc fusion protein library to screen for CTLR/pathogen interactions.

17.
Wound Repair Regen ; 17(3): 447-55, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19660054

RESUMO

Digit regrowth following amputation injury proximal to the first phalangeal joint is not a property of mammalian wound healing. However, the regenerative potential observed in the MRL mouse invites a reexamination of this rule. In this study, healing was assessed in three mouse strains after amputation midway through the second phalangeal bone. Three distinct outcomes were observed though evidence for regrowth was observed only in the MRL mouse. Here, a blastema-like structure was seen along with apparent chondrogenesis, consistent with a histological profile of a regenerative response to injury. Analysis of trichrome staining and basement membrane changes, proliferation and apoptosis indicated that these processes contributed to the formation of new digit tissue. On the other hand, SW and B6 digits did not show evidence of growth with little mesenchymal BrdU incorporation or phosphorylation of H3.


Assuntos
Apoptose/fisiologia , Dedos do Pé/cirurgia , Cicatrização/fisiologia , Amputação Cirúrgica , Animais , Regeneração Óssea/fisiologia , Proliferação de Células , Modelos Animais de Doenças , Feminino , Seguimentos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos MRL lpr
18.
Biol Aujourdhui ; 209(1): 97-109, 2015.
Artigo em Francês | MEDLINE | ID: mdl-26115715

RESUMO

Phosphoinositides (PPIn) are lipids involved in the vesicular transport of proteins between the different intracellular compartments. They act by recruiting and/or activating effector proteins and are thus involved in crucial cellular functions including vesicle budding, fusion and dynamics of membranes and regulation of the cytoskeleton. Although they are present in low concentrations in membranes, their activity is essential for cell survival and needs to be tightly controlled. Therefore, phosphatases and kinases specific of the various cellular membranes can phosphorylate/dephosphorylate their inositol ring on the positions D3, D4 and/or D5. The differential phosphorylation determines the intracellular localisation and the activity of the PPIn. Indeed, non-phosphorylated phosphatidylinositol (PtdIns) is the basic component of the PPIn and can be found in all eukaryotic cells at the cytoplasmic face of the ER, the Golgi, mitochondria and microsomes. It can get phosphorylated on position D4 to obtain PtdIns4P, a PPIn enriched in the Golgi compartment and involved in the maintenance of this organelle as well as anterograde and retrograde transport to and from the Golgi. PtdIns phosphorylation on position D3 results in PtdIns3P that is required for endosomal transport and multivesicular body (MVB) formation and sorting. These monophosphorylated PtdIns can be further phosphorylated to produce bisphophorylated PtdIns. Thus, PtdIns(4,5)P2, mainly produced by PtdIns4P phosphorylation, is enriched in the plasma membrane and involved in the regulation of actin cytoskeleton and endocytosis. PtdIns(3,5)P2, mainly produced by PtdIns3P phosphorylation, is enriched in late endosomes, MVBs and the lysosome/vacuole and plays a role in endosome to vacuole transport. PtdIns(3,4)P2 is absent in yeast, cells and mainly produced by PtdIns4P phosphorylation in human cells; PtdIns(3,4)P2 is localised in the plasma membrane and plays an important role as a second messenger by recruiting specific protein kinases (Akt and PDK1). Finally the triple phosphorylated PPIn, PtdIns(3,4,5)P3 also absent in yeast, is produced by the phosphorylation of PtdIns(3,4)P2 and localized at the plasma membrane of human cells where it binds proteins via their PH domain. Interaction partners include members of the Arf (ADP-ribosylation factors) family, PDK1 (Phosphoinositide Dependent Kinase 1) and Akt. Therefore this last PPIn is essential for the control of cell proliferation and its deregulation leads to the development of numerous cancers. In conclusion, the regulation of PPIn phosphorylation/dephosphorylation is complex and needs to be very precisely regulated. Indeed phosphatases and kinases allow the maintenance of the equilibrium between the different forms. PPIn play a crucial role in numerous cellular functions and a loss in their synthesis or regulation results in severe genetic diseases.


Assuntos
Espaço Intracelular/metabolismo , Fosfatidilinositóis/fisiologia , Vesículas Transportadoras/fisiologia , Transporte Biológico , Membrana Celular/química , Membrana Celular/enzimologia , Endocitose , Retículo Endoplasmático/química , Endossomos , Complexo de Golgi/química , Humanos , Inositol/metabolismo , Espaço Intracelular/química , Microssomos/química , Mitocôndrias/química , Fosfatos de Fosfatidilinositol/fisiologia , Fosfatidilinositóis/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Fosfotransferases/metabolismo , Sistemas do Segundo Mensageiro , Vacúolos , Proteínas de Transporte Vesicular
19.
Am J Med Genet ; 69(4): 418-21, 1997 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-9098494

RESUMO

We report on a further case of Goldenhar complex with uncommon and clinically remarkable associated anomalies. This additional case increases the number of observations and descriptions of patients with "expanded Goldenhar complex." Pathogenetic aspects are discussed.


Assuntos
Anormalidades Múltiplas , Síndrome de Goldenhar , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Evolução Fatal , Feminino , Síndrome de Goldenhar/diagnóstico por imagem , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/patologia , Deformidades Congênitas da Mão , Humanos , Lactente , Radiografia , Coluna Vertebral/anormalidades , Ultrassonografia
20.
J Clin Forensic Med ; 10(2): 77-80, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15275025

RESUMO

Rapid, semi-quantitative measurement of carboxyhemoglobin (COHb) in close temporal proximity to a post-mortem examination can prove to be extremely useful, and provide potentially life-saving information. Other inhabitants of a dwelling with faulty heating or operators of older or poorly maintained motor vehicles with faulty exhaust systems could be quickly informed of potentially dangerous situations. We describe a method for assessing the COHb concentration which will confirm a negative result in 30-40 min and rule out significant levels in less than 2 h, utilizing common reagents and requiring no instrumentation. The method depends on a reaction between formaldehyde and hemoglobin, with associated color change from red to brown.

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