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1.
Indian J Otolaryngol Head Neck Surg ; 76(4): 3412-3417, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39130227

RESUMO

To study the efficacy of low-level laser therapy in the management of temporomandibular joint arthralgia. Design Interventional study (pre-post study), Setting Meenakshi Medical College And Hospital, Research Institute. Subjects 50 patients with temporomandibular joint arthralgia were evaluated for pain, mouth opening and clicking sound while mouth opening before and after treatment. Method Patients are subjected to undergo low-level laser therapy with Infrared and red rays with a therapeutic dosage ranging from 8 J/cm2 to 15 J/cm2 up to 3-5 sessions for a month each session lasts for 15-20 min. The patients are to be followed up regularly after 1, 3, 6 and 8 months in the study.The study measured the range of mouth opening in patients before and after undergoing low-level laser therapy. Before treatment, the range of mouth opening was from 2.78 to 3.97 cm, with a mean value of 2.78 cm and a standard deviation of 0.22. After treatment, the range of mouth opening was from 2.78 to 3.97 cm, with a mean value of 3.97 cm and a standard deviation of 0.24. The study also measured the VAS score for pain, with a mean and standard deviation of 7.9 ± 0.73 before treatment and 0.88 ± 0.718 after treatment. There was a significant difference between the pretreatment and post-treatment VAS scores, with a P-value of 0.05. Low-level laser therapy is an effective non invasive treatment modality for temporomandibular joint arthralgia. The patients who underwent this procedure had symptomatic relief and no remissions were observed.

2.
Exp Appl Acarol ; 75(3): 333-343, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30027323

RESUMO

In vitro acaricidal activity of Piper nigrum and P. longum fruit extracts and their active components (piperine for P. nigrum and piperine and piperlonguminine for P. longum) was evaluated against adults engorged females of Rhipicephalus (Boophilus) microplus using adult immersion test. Three concentrations of each extract with four replications were used in the bioassay. Extracts significantly affected mortality rates of ticks in dose-dependent manner ranged 12.5-95.8% for P. nigrum and 29.2-87.5% for P. longum, with an additional effect on the reproductive physiology of ticks by inhibiting oviposition (28.1-96.9% by P. nigrum and 36.1-89.3% by P. longum). However, the acaricidal and oviposition limiting properties were decreased significantly when the active component(s) of each extract was tested separately. However, the combination of piperine and piperlonguminine (obtained from P. longum extract) caused 79.2% mortality of ticks which is equivalent to the corresponding concentration (~ 5%) of the extract. It can be concluded that the fruit extracts of P. nigrum and P. longum had both acaricidal and oviposition limiting actions against the adults of R. (B.) microplus which could make it a valuable component of developing sustainable strategy for integrated tick management.


Assuntos
Acaricidas/toxicidade , Piper nigrum/química , Piper/química , Extratos Vegetais/toxicidade , Rhipicephalus/efeitos dos fármacos , Acaricidas/isolamento & purificação , Animais , Feminino , Frutas/química
4.
Ann Med Health Sci Res ; 3(3): 320-3, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24116306

RESUMO

The menopause is physiological changes in women that give rise to adaptive changes at both systemic and oral level. As we all begin to reach an older age, dental health and hygiene becomes a major concern. The dentist is often the first person to appreciate numerous changes that are experienced throughout the body during menopause. The teeth and gums are extremely susceptible to any hormonal changes that take place just before menopause and readily decrease body's ability to fight off minor infections or maintain a healthy balance of useful and harmful bacteria within the oral environment. This review aimed to develop better understanding for major oro-dental complications observed in women during menopause, and schematic approach towards the different dental management protocols used during these periods. Various internets based popular search engines were used to explore related data from literature, which includes PubMed, PubMed Central, Cochrane, Google, Medknow, Ebsco, Science Direct, and IndMed. Upon compilation of relevant data, it was observed that periodontal health is most severely affected (up to 60%) followed by dry mouth (25%) and burning mouth (glossodynia; 15%) which, in turn, may increase the occurrence of oral mucosal and dental diseases, such as candidiasis. Though, the usage of hormone replacement therapy is effective but it does not necessarily prevent or help women with oral symptoms. Therefore, well controlled long-term randomized studies are needed to establish more authentic clinical guidelines for successful management of such conditions.

5.
Environ Monit Assess ; 172(1-4): 249-62, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20151189

RESUMO

Electronic waste or E-waste comprises of old, end-of-life electronic appliances such as computers, laptops, TVs, DVD players, refrigerators, freezers, mobile phones, MP3 players, etc., which have been disposed of by their original users. E-waste contains many hazardous constituents that may negatively impact the environment and affect human health if not properly managed. Various organizations, bodies, and governments of many countries have adopted and/or developed the environmentally sound options and strategies for E-waste management to tackle the ever growing threat of E-waste to the environment and human health. This paper presents E-waste composition, categorization, Global and Indian E-waste scenarios, prospects of recoverable, recyclable, and hazardous materials found in the E-waste, Best Available Practices, recycling, and recovery processes followed, and their environmental and occupational hazards. Based on the discussion, various challenges for E-waste management particularly in India are delineated, and needed policy interventions were discussed.


Assuntos
Resíduo Eletrônico , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/métodos , Índia
6.
Sci Total Environ ; 409(1): 19-32, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20951410

RESUMO

The problem of E-waste has forced Environmental agencies of many countries to innovate, develop and adopt environmentally sound options and strategies for E-waste management, with a view to mitigate and control the ever growing threat of E-waste to the environment and human health. E-waste management is given the top priority in many developed countries, but in rapid developing countries like India, it is difficult to completely adopt or replicate the E-waste management system in developed countries due to many country specific issues viz. socio-economic conditions, lack of infrastructure, absence of appropriate legislations for E-waste, approach and commitments of the concerned, etc. This paper presents a review and assessment of the E-waste management system of developed as well as developing countries with a special emphasis on Switzerland, which is the first country in the world to have established and implemented a formal E-waste management system and has recycled 11kg/capita of WEEE against the target of 4kg/capita set by EU. And based on the discussions of various approaches, laws, legislations, practices of different countries, a road map for the development of sustainable and effective E-waste management system in India for ensuring environment, as well as, occupational safety and health, is proposed.


Assuntos
Resíduo Eletrônico/estatística & dados numéricos , Poluição Ambiental/prevenção & controle , Gerenciamento de Resíduos/métodos , Conservação dos Recursos Naturais , Resíduo Eletrônico/economia , Política Ambiental , Poluição Ambiental/legislação & jurisprudência , Poluição Ambiental/estatística & dados numéricos , Índia , Gerenciamento de Resíduos/legislação & jurisprudência
7.
Methods Mol Biol ; 547: 139-53, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19521842

RESUMO

We have developed a rapid in vitro propagation system, via axillary shoot formation from nodal explants of Swertia chirata Buch Ham. Culture medium supplemented with 2 mg/L. BAP is best for direct shoot regeneration initially formed adventitious buds from axils of the nodal explants after 30 days. The reduced BAP concentration 0.5 mg/L proliferate shoots effectively. Kept the number of hyperhydrated shoots to minimal and induced on an average 22-38 shoots per flask (4.3 cm average length). The regenerated shoots (5- to 6-m long) formed roots very well in Murashige and Skoog (MS) medium devoid of any growth regulator and followed by acclimatization of plants in pre-sterilized sand containing 1% Trichoderma viride and Azatobactor chrococcum as bioinoculants. The regenerated plants don't show any genomic alterations. This protocol also outlines procedure of assessment of marker iridoid glycosides (amarogentin and amaroswerin) from callus, roots, multiple shoots, regenerated plants, and mother plant. High propagation frequency, reproducibility of procedure, molecular, and phenotypic and chemical stability ensures the efficiency of the developed protocol.


Assuntos
Glicosídeos/metabolismo , Swertia/metabolismo , Biomarcadores , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Espectroscopia de Ressonância Magnética , Reação em Cadeia da Polimerase , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Swertia/crescimento & desenvolvimento , Técnicas de Cultura de Tecidos
8.
Mol Cell Biol ; 22(1): 257-69, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11739739

RESUMO

v-Src-induced oncogenic transformation is characterized by alterations in cell morphology, adhesion, motility, survival, and proliferation. To further elucidate some of the signaling pathways downstream of v-Src that are responsible for the transformed cell phenotype, we have investigated the role that the calpain-calpastatin proteolytic system plays during oncogenic transformation induced by v-Src. We recently reported that v-Src-induced transformation of chicken embryo fibroblasts is accompanied by calpain-mediated proteolytic cleavage of the focal adhesion kinase (FAK) and disassembly of the focal adhesion complex. In this study we have characterized a positive feedback loop whereby activation of v-Src increases protein synthesis of calpain II, resulting in degradation of its endogenous inhibitor calpastatin. Reconstitution of calpastatin levels by overexpression of exogenous calpastatin suppresses proteolytic cleavage of FAK, morphological transformation, and anchorage-independent growth. Furthermore, calpastatin overexpression represses progression of v-Src-transformed cells through the G(1) stage of the cell cycle, which correlates with decreased pRb phosphorylation and decreased levels of cyclins A and D and cyclin-dependent kinase 2. Calpain 4 knockout fibroblasts also exhibit impaired v-Src-induced morphological transformation and anchorage-independent growth. Thus, modulation of the calpain-calpastatin proteolytic system plays an important role in focal adhesion disassembly, morphological transformation, and cell cycle progression during v-Src-induced cell transformation.


Assuntos
Quinases relacionadas a CDC2 e CDC28 , Proteínas de Ligação ao Cálcio/metabolismo , Calpaína/metabolismo , Transformação Celular Neoplásica , Proteína Oncogênica pp60(v-src)/metabolismo , Actinas/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Calpaína/antagonistas & inibidores , Calpaína/genética , Divisão Celular/fisiologia , Tamanho Celular , Células Cultivadas , Embrião de Galinha , Ciclina A/metabolismo , Ciclina D , Quinase 2 Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Citoesqueleto/metabolismo , Retroalimentação Fisiológica/fisiologia , Fibroblastos/fisiologia , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Adesões Focais/metabolismo , Genes myc , Genes ras , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Modelos Biológicos , Proteína Oncogênica p65(gag-jun)/metabolismo , Proteínas Oncogênicas v-fos/metabolismo , Isoformas de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteína do Retinoblastoma/metabolismo , Temperatura
9.
J Biol Chem ; 276(51): 48382-8, 2001 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-11602605

RESUMO

The physiological functions and substrates of the calcium-dependent protease calpain remain only partly understood. The mu- and m-calpains consist of a mu- or m-80-kDa large subunit (genes Capn1 and Capn2), and a common 28-kDa small subunit (Capn4). To assess the role of calpain in migration, we used fibroblasts obtained from Capn4(-/-) mouse embryos. The cells lacked calpain activity on casein zymography and did not generate the characteristic calpain-generated spectrin breakdown product that is observed in wild-type cells. Capn4(-/-) cells had decreased migration rates and abnormal organization of the actin cytoskeleton with a loss of central stress fibers. Interestingly, these cells extended numerous thin projections and displayed delayed retraction of membrane protrusions and filopodia. The number of focal adhesions was decreased in Capn4(-/-) cells, but the cells had prominent vinculin-containing focal complexes at the cell periphery. The levels of the focal adhesion proteins, alpha-actinin, focal adhesion kinase (FAK), spectrin, talin, and vinculin, were the same in Capn4(+/+) and Capn4(-/-) cells. FAK, alpha-actinin, and vinculin were not cleaved in either cell type plated on fibronectin. However, proteolysis of the focal complex component, talin, was detected in the wild-type cells but not in the Capn4(-/-) cells, suggesting that calpain cleavage of talin is important during cell migration. Moreover, talin cleavage was again observed when calpain activity was partially restored in Capn4(-/-) embryonic fibroblasts by stable transfection with a vector expressing the rat 28-kDa calpain small subunit. The results demonstrate unequivocally that calpain is a critical regulator of cell migration and of the organization of the actin cytoskeleton and focal adhesions.


Assuntos
Actinas/metabolismo , Calpaína/fisiologia , Movimento Celular/fisiologia , Citoesqueleto/metabolismo , Embrião de Mamíferos/metabolismo , Animais , Antígenos Transformantes de Poliomavirus/fisiologia , Calpaína/genética , Linhagem Celular , Linhagem Celular Transformada , Embrião de Mamíferos/citologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Hidrólise , Camundongos , Ratos , Talina/metabolismo
10.
J Virol ; 75(13): 6218-22, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11390626

RESUMO

Fibronectin fragments have been shown to improve retrovirus gene transfer efficiency by binding retrovirus and target cells. Using a novel virus adhesion assay, we confirmed binding of type C oncoretrovirus vectors to the heparin II domain of fibronectin and demonstrated inhibition of viral binding and gene transfer by heparin.


Assuntos
Fibronectinas/fisiologia , Transferência Genética Horizontal , Heparina/farmacologia , Retroviridae/efeitos dos fármacos , Antígenos CD34/análise , Centrifugação com Gradiente de Concentração , Células-Tronco Hematopoéticas/metabolismo , Metionina/metabolismo , Retroviridae/genética , Retroviridae/fisiologia
11.
Pediatr Radiol ; 30(6): 369-78, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10876818

RESUMO

BACKGROUND: The use of radiographic contrast media in the setting of possible bowel ischemia and potential perforation is known to be associated with increased clinical risk. However, there is a lack of controlled studies using a standard native fecal load to define and compare the intrinsic mortality and morbidity among options of contrast media currently available to the radiologist. We have compared the mortality and gross and histopathologic morbidity of a standard intraperitoneal native fecal dose in the guinea pig, using barium, two iodinated media, saline and air. MATERIALS AND METHODS: The study was performed on adult Hartley guinea pigs. A standard native fecal solution with a colony count of 10(8) aerobes and 2 x 10(7) anaerobes was prepared, and the LD50 of intraperitoneal injection of the solution was determined. The standard solution at the LD50 dose was then used to compare the mortality and morbidity when commercial barium sulfate (18% w/v), Conray 30 (iothalamate meglumine 30%), 1:1 dilution of Conray 30 with sterile water, termed Conray "15" (iothalamate meglumine 15%), saline and air, were added to the intraperitoneal injection of the fecal solution in five groups of 20 animals each. Mortality and acute (96 h) and chronic (30 days) gross and histopathology were assessed and graded according to a standard system and analyzed statistically. RESULTS: Barium was significantly more deleterious than the dilute water-soluble iodinated media, saline and air. Mortality occurred within 24 h in the barium group and within the initial 48 h in all groups as follows: barium 19/20 (95%); Conray 30 16/20 (80%); Conray "15" 7/20 (35%); saline 0; air 0. Acute gross and histopathology showed extensive grade 4 lesions in 19/19 barium animals; less severe lesions were present in a lesser percentage of the animals in the other four groups. Entirely chronic lesions were present only in the single surviving barium animal and were non-significant (< 400 microns) or absent in the other four groups. CONCLUSIONS: In our study, barium incurred the most significant deleterious short and long-term effects in the setting of fecal peritonitis. Dilute water-soluble media offer a much greater margin of safety. Saline under sonographic guidance is less deleterious than any of the positive radiographic contrast media. However, in our study, air was the safest contrast medium in the setting of peritoneal soiling.


Assuntos
Sulfato de Bário/efeitos adversos , Meios de Contraste/efeitos adversos , Fezes , Iotalamato de Meglumina/efeitos adversos , Peritonite/mortalidade , Animais , Sulfato de Bário/administração & dosagem , Meios de Contraste/administração & dosagem , Relação Dose-Resposta a Droga , Cobaias , Iotalamato de Meglumina/administração & dosagem , Peritonite/patologia
12.
Biochem J ; 348 Pt 1: 37-43, 2000 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10794711

RESUMO

m-Calpain is a heterodimeric, cytosolic, thiol protease, which is activated by Ca(2+)-binding to EF-hands in the C-terminal domains of both subunits. There are four potential Ca(2+)-binding EF-hands in each subunit, but their relative affinities for Ca(2+) are not known. In the present study mutations were made in both subunits to reduce the Ca(2+)-binding affinity at one or more EF-hands in one or both subunits. X-ray crystallography of some of the mutated small subunits showed that Ca(2+) did not bind to the mutated EF-hands, but that its binding at other sites was not affected. The structures of the mutant small subunits in the presence of Ca(2+) were otherwise identical to that of the Ca(2+)-bound wild-type small subunit. In the whole enzyme the wild-type macroscopic Ca(2+) requirement (K(d)) was approx. 350 microM. The mutations did not affect the maximum specific activity of the enzyme, but caused increases in K(d), which were characteristic of each site. All the EF-hands could be mutated in various combinations without loss of activity, but preservation of at least one wild-type EF-hand 3 sequence was required to maintain K(d) values lower than 1 mM. The results suggest that all the EF-hands can contribute co-operatively to calpain activation, but that EF-hand 3, in both subunits, has the highest intrinsic affinity for Ca(2+) and provides the major driving force for conformational change.


Assuntos
Cálcio/farmacologia , Calpaína/metabolismo , Motivos EF Hand/fisiologia , Animais , Calpaína/química , Calpaína/genética , Cristalografia por Raios X , Dimerização , Ativação Enzimática , Modelos Moleculares , Mutação , Conformação Proteica , Ratos , Térbio/farmacologia , Titulometria
13.
Arch Biochem Biophys ; 377(1): 22-30, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10775437

RESUMO

A structural model of Bacillus subtilis cytochrome c-550 has been built based upon hydropathy analysis, sequence alignment, homology modeling, and energy minimization. The model has a single transmembrane alpha-helix and a water-soluble domain folded around covalently attached heme C. Physical measurements on purified, recombinant cytochrome c-550 have been made to test aspects of the model. Excitation at either 280 or 295 nm yields fluorescence with an emission maximum at 334 nm and a quantum yield of 25% relative to n-acetyltryptophanamide. The model places one (i.e., W115) of the two tryptophans of cytochrome c-550 in the heme domain and the second (i.e., W3) in the transmembrane domain. The indole ring of W115 is within 5 A of the heme macrocycle and is expected to be highly quenched via resonance energy transfer to the heme. In contrast, W3 is at the start of the putative transmembrane helix and could be located a considerable distance from the heme. Förster theory assigns a distance of 42 A from W3 to the heme. This distance is important in adjusting the relative positions of the membrane-spanning and heme-binding domains. Circular dichroism measurements in the ultraviolet region indicate increased alpha-helical content of B. subtilis cytochrome c compared to mitochondrial cytochrome c in support of an alpha-helical transmembrane domain. The ionic strength dependence of redox kinetics for cytochrome c-550 indicates an overall negative charge that is consistent with a calculated pI of 5.4. However, the charge distribution specified by the model indicates a surface for electron exchange that is different from the classical front face used by mitochondrial cytochrome c.


Assuntos
Bacillus subtilis/química , Membrana Celular/metabolismo , Grupo dos Citocromos c/química , Grupo dos Citocromos c/metabolismo , Proteínas de Membrana/metabolismo , Modelos Moleculares , Sequência de Aminoácidos , Animais , Dicroísmo Circular , Grupo dos Citocromos c/isolamento & purificação , Elétrons , Heme/metabolismo , Cavalos , Cinética , Proteínas de Membrana/química , Proteínas de Membrana/isolamento & purificação , Dados de Sequência Molecular , Concentração Osmolar , Oxirredução , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Espectrometria de Fluorescência , Eletricidade Estática , Termodinâmica , Triptofano/metabolismo
14.
FEBS Lett ; 436(3): 367-71, 1998 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-9801150

RESUMO

The hypothesis that calpain subunits dissociate in the presence of Ca2+ has been tested by methods which avoid interference by Ca2+-induced aggregation and large subunit autolysis. Inactive Cys105Ser-m-calpain, bound either to Ni-NTA-agarose or to immobilized casein, after incubation with Ca2+, could be recovered in high yield as a heterodimer. Natural bovine m-calpain, after irreversible inhibition with Z-LLY-CHN2, also bound to immobilized casein and was eluted as a heterodimer. The Ca2+ requirements of calpain containing a small subunit with EF-hand mutations were higher, both before and after autolysis, than those of wild-type calpain. In mixtures of wild-type and mutant enzymes, subunit exchange did not occur in the presence of Ca2+. The results demonstrate that the subunits in both natural and recombinant m-calpain, in the given experimental conditions, remain associated in the presence of Ca2+ both before and after autolysis.


Assuntos
Cálcio/farmacologia , Calpaína/química , Alanina , Animais , Calpaína/efeitos dos fármacos , Calpaína/metabolismo , Caseínas/metabolismo , Domínio Catalítico , Bovinos , Cisteína , Dimerização , Ácido Glutâmico , Cinética , Substâncias Macromoleculares , Mutagênese Sítio-Dirigida , Ligação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/metabolismo , Serina
15.
J Immunol ; 161(7): 3652-8, 1998 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9759889

RESUMO

Stromal cell-derived factor (SDF-1alpha), the ligand for CXCR4, is a chemokine that acts as a potent chemoattractant for hemopoietic progenitor cells. Stem cell factor/kit ligand (SCF/KL), an early acting cytokine, has recently been reported to enhance the chemotaxis induced by SDF-1alpha. However, very little is known about downstream signaling events following these receptor-ligand interactions. To investigate these events, we utilized a model progenitor cell line, CTS, which expresses both the CXCR4 and c-kit receptors. We observed strong Ca2+ mobilization and enhancement of chemotaxis following treatment with SDF-1alpha or SCF/KL. A combination of these factors enhanced this chemotaxis in CTS cells as well as in CD34+ bone marrow cells. Prior treatment of CTS cells with pertussis toxin inhibited the SDF-1alpha-induced chemotaxis, suggesting that SDF-1alpha signaling involves a pertussis-sensitive Gi-coupled protein. SDF-1alpha treatment resulted in a rapid phosphorylation of the focal adhesion molecules RAFTK (related adhesion focal tyrosine kinase), paxillin, and p130cas, which then declined within minutes. SCF/KL alone or in combination with SDF-1alpha induced a rapid and sustained effect on phosphorylation of these substrates. SDF-1alpha treatment resulted in a rapid and robust activation of p44/42 mitogen-activated protein kinase compared with the relatively weak and delayed effect of SCF/KL treatment. Interestingly, a delayed but sustained activation of mitogen-activated protein kinase activation was observed when the factors were used in combination. Such cooperativity in downstream signaling pathways may explain the enhanced chemotaxis of progenitors observed with SDF-1alpha in combination with SCF/KL.


Assuntos
Quimiocinas CXC/fisiologia , Quimiotaxia de Leucócito/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Proteínas Quinases Ativadas por Mitógeno , Proteínas , Transdução de Sinais/fisiologia , Fator de Células-Tronco/fisiologia , Antígenos CD34/análise , Células da Medula Óssea/imunologia , Células da Medula Óssea/fisiologia , Cálcio/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Linhagem Celular , Quimiocina CXCL12 , Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/imunologia , Proteína Substrato Associada a Crk , Proteínas do Citoesqueleto/metabolismo , Ativação Enzimática/efeitos dos fármacos , Quinase 2 de Adesão Focal , Células-Tronco Hematopoéticas/enzimologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno , Proteínas de Membrana/análise , Paxilina , Fosfoproteínas/metabolismo , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Proteína p130 Retinoblastoma-Like , Transdução de Sinais/imunologia , Tirosina/efeitos dos fármacos , Tirosina/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
16.
J Biol Chem ; 273(36): 23169-75, 1998 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-9722546

RESUMO

The alpha-chemokine stromal cell-derived factor (SDF)-1alpha binds to the seven transmembrane G-protein-coupled CXCR-4 receptor and acts to modulate cell migration and proliferation. The signaling pathways that mediate the effects of SDF-1alpha are not well characterized. We studied events following SDF-1alpha binding to CXCR-4 in a model murine pre-B cell line transfected with human CXCR-4. There was enhanced tyrosine phosphorylation and association of components of focal adhesion complexes such as the related adhesion focal tyrosine kinase, paxillin, and Crk. We also observed activation of phosphatidylinositol 3-kinase. Wortmannin, a selective inhibitor of phosphatidylinositol 3-kinase, partially inhibited the SDF-1alpha-induced migration and tyrosine phosphorylation of paxillin. SDF-1alpha treatment selectively activated p44/42 mitogen-activated protein kinase (Erk 1 and Erk 2) and its upstream kinase mitogen-activated protein kinase kinase but not p38 mitogen-activated protein kinase, c-Jun amino-terminal kinase or mitogen activated protein kinase kinase. We also observed that SDF-1alpha treatment increased NF-kappaB activity in nuclear extracts from the CXCR-4 transfectants. Taken together, these studies revealed that SDF-1alpha activates distinct signaling pathways that may mediate cell growth, migration, and transcriptional activation.


Assuntos
Quimiocinas CXC/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Receptores CXCR4/metabolismo , Animais , Linfócitos B/citologia , Cálcio/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Adesão Celular , Divisão Celular/fisiologia , Quimiocina CXCL12 , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/fisiologia , Quinase 2 de Adesão Focal , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , NF-kappa B/metabolismo , Paxilina , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Ligação Proteica , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores CXCR4/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Transfecção
17.
Biochem Cell Biol ; 76(1): 129-37, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9666315

RESUMO

Much of the fruit fly genome is compact ("Escherichia coli mode"), indicating a genome-wide selection pressure against DNA with little adaptive function. However, in the bithorax complex (BX-C) homeodomain genes are widely dispersed with large introns ("mammalian mode"). Chargaff difference analysis of compact bacterial and viral genomes has shown that most mRNAs have the potential to form stem-loop structures with purine-rich loops. Thus, for many taxa if transcription is to the right, the top (mRNA synonymous) DNA strand has purine-rich loop potential, and if transcription is to the left, the top (template) strand has pyrimidine-rich loop potential. The best indicator bases for transcription direction are A and T for AT-rich genomes, and C and G for CG-rich genomes. Consistent with this, Chargaff difference analysis of BX-C genes and several non-BX-C genes shows that, whatever the mode, mRNAs have the potential to form stem-loop structures with A-rich loops. We confirm that many potential open reading frames in the BX-C are unlikely to be functional. Conversely, we suggest that a few unassigned open reading frames may actually be functional. Since apparent organization in the mammalian mode cannot be explained in terms of unacknowledged open reading frames, yet the fruit fly genome is under pressure to be compact, it is likely that many BX-C functions do not involve the encoding of proteins.


Assuntos
Composição de Bases , Drosophila melanogaster/genética , Genes Homeobox , Genes de Insetos , Genoma , Transcrição Gênica , Animais , Éxons , Mamíferos/genética , Estatística como Assunto
18.
Blood ; 91(3): 791-7, 1998 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9446638

RESUMO

Chemokine receptors are coupled to G-proteins and their activation results in prominent changes in cell migration and growth. The downstream signaling pathways that mediate these effects of chemokines are largely uncharacterized. Macrophage inflammatory protein 1 beta (MIP 1 beta) binding to its cognate receptor CCR5 resulted in activation of the related adhesion focal tyrosine kinase (RAFTK), with subsequent activation of the cytoskeletal protein paxillin and the down-stream transcriptional activators, c-Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPK) and p38 mitogen-activated protein (MAP) kinase. Inhibition of RAFTK by a dominant-negative kinase mutant markedly attenuated JNK/ SAPK activity. Thus, RAFTK appears to provide a functional "bridge" for the transmission of CCR5 receptor signaling to the cytoskeleton and nucleus, primary sites of chemotaxis and growth regulation.


Assuntos
Proteínas Quinases Ativadas por Mitógeno , Proteínas Tirosina Quinases/metabolismo , Receptores CCR5/fisiologia , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Quimiocina CCL4 , Proteínas do Citoesqueleto/metabolismo , Ativação Enzimática , Quinase 2 de Adesão Focal , Humanos , Técnicas de Imunoadsorção , Proteínas Quinases JNK Ativadas por Mitógeno , Linfoma , Proteínas Inflamatórias de Macrófagos/metabolismo , Proteínas Inflamatórias de Macrófagos/farmacologia , Camundongos , Paxilina , Fosfoproteínas/metabolismo , Fosforilação , Receptores CCR5/genética , Transfecção , Células Tumorais Cultivadas
19.
Immunity ; 7(3): 335-44, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9324354

RESUMO

The site of origin of lymphohematopoietic stem cells (HSC) that initiate definitive blood cell production in the murine fetal liver is controversial. Contrary to reports that the preliver yolk sac does not contain definitive HSC, we observed that CD34+ day 9 yolk sac cells repopulated multiple blood cell lineages in newborn hosts for at least 1 year. Furthermore, 100 CD34+c-Kit+ day 9 yolk sac or para-aortic splanchnopleura (P-Sp) cells, known to give rise to embryonic HSC, similarly repopulated hematopoiesis in recipient hosts. Surprisingly, 37-fold more CD34+c-Kit+ cells reside in the day 9 yolk sac than in the P-Sp. In sum, definitive HSC are coexistent, but not equal in number, in the murine yolk sac and P-Sp prior to fetal liver colonization.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Saco Vitelino/citologia , Animais , Antígenos CD34/metabolismo , Feminino , Feto/metabolismo , Substâncias de Crescimento/genética , Fígado/embriologia , Camundongos , Fenótipo , Gravidez , Proteínas Proto-Oncogênicas c-kit/metabolismo , RNA Mensageiro/metabolismo , Ratos , Fatores de Transcrição/genética , Saco Vitelino/metabolismo
20.
Biochem Mol Biol Int ; 42(5): 909-17, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9285058

RESUMO

Gene transfer into hematopoietic progenitor cells is increased when these cells are adherent to the carboxy-terminal chymotryptic fragment of human plasma fibronectin (FN30/35) containing the heparin binding domain (HBD) and the alternatively spliced type three connecting segment (IIICS) region. We report herein the production of a recombinant human fibronectin fragment comprised of the HBD and IIICS regions expressed by Sf9 insect cells following recombinant baculovirus infection. The resulting isolated peptide, HuBacFN, facilitated gene transfer into human hematopoietic cell lines and primary human hematopoietic progenitors to a level achieved with the purified human plasma FN30/35 peptide.


Assuntos
Fibronectinas/genética , Técnicas de Transferência de Genes , Células-Tronco Hematopoéticas/fisiologia , Fragmentos de Peptídeos/genética , Sequência de Bases , Fibronectinas/química , Vetores Genéticos , Humanos , Dados de Sequência Molecular , Mutação Puntual , Proteínas Recombinantes/genética , Retroviridae
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