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1.
Eur Rev Med Pharmacol Sci ; 26(8): 2960-2969, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35503640

RESUMO

OBJECTIVE: This report aimed to characterize clinical and imaging characteristics and outcomes of the patients with lower cervical spine injury combined with spinal cord paralysis who underwent posterior cervical spine surgery. PATIENTS AND METHODS: Between January 2019 and December 2020, a retrospective evaluation of prospectively collected data at one institution was conducted. We included all patients who were diagnosed with subaxial cervical spine injuries (C3-7), had spinal cord paralysis, and underwent posterior cervical spine surgery. Clinical profile, preoperative characteristics, intraoperative data, and postoperative outcomes were retrieved from prospective patients' medical records and computerized database. RESULTS: Among 70 selected patients, most were male (66, 94.29%) and the average age was 48.41 ± 14.33 years. Most of them worked in agriculture (90.4%). Clinical symptoms included neck pain (58, 82.86%), cervical radiculopathy (50, 71.43%), loss of sensation (44, 62.86%), and decreased sensation (21, 30.00%). The most frequent cervical spinal injuries involved C5 (28.57%), followed by C7 (14.29%). Circular muscle dysfunction was present in 65 (92.86%) patients. Early complications included respiratory failure (12.85%), pneumonia (11.42%), bedsores (8.57%), and urinary tract infection (7.14%). Common late complications included movement disorder (48.21%), muscle weakness and stiffness (37.50%), sensory disturbances (32.14%), urinary tract infection (17.86%), bedsores (16.07%), and pneumonia (5.36%). Patients after surgery and at follow-up had a significant improvement compared to preoperative assessment according to the AIS classification, and recovery of smooth muscle. Three patients died within 1 month following surgery, 3 within 1-3 month(s), 2 within 3-6 months, and 1 case beyond 6 months. CONCLUSIONS: In hospital-based clinical condition with limited practice approach, our study indicated specific clinical and imaging characteristics of Vietnamese patients with lower cervical spine injury combined with spinal cord paralysis. With high postoperative mortality rate, commonly late complications after posterior cervical spine surgical approach were pain and difficulty in neck movement, muscle weakness and stiffness, and nerve root pain.


Assuntos
Úlcera por Pressão , Doenças da Coluna Vertebral , Traumatismos da Coluna Vertebral , Adulto , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Debilidade Muscular , Dor , Paralisia , Complicações Pós-Operatórias , Estudos Prospectivos , Estudos Retrospectivos , Medula Espinal , Resultado do Tratamento
2.
Int J Infect Dis ; 46: 56-60, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27044521

RESUMO

UNLABELLED: Tuberculosis (TB) and human immunodeficiency virus (HIV) infection are leading causes of disease and death in Vietnam, but TB/HIV disease trends and the profile of co-infected patients are poorly described. METHODS: We examined national TB and HIV notification data to provide a geographic overview and describe relevant disease trends within Vietnam. We also compared the demographic and clinical profiles of TB patients with and without HIV infection. RESULTS: During the past 10 years (2005-2014) cumulative HIV case numbers and deaths increased to 298,151 and 71,332 respectively, but access to antiretroviral therapy (ART) improved and new infections and deaths declined. From 2011-2014 routine HIV testing of TB patients increased from 58.9% to 72.5% and of all TB patients diagnosed with HIV in 2014, 2,803 (72.4%) received ART. The number of multidrug resistant (MDR)-TB cases enrolled for treatment increased almost 3-fold (578 to 1,532) from 2011-2014. The rate of HIV co-infection in MDR and non-MDR TB cases (51/1,532; 3.3% vs 3,774/100,555; 3.8%; OR 0.77, 95% CI 0.7-1.2) was similar in 2014. CONCLUSIONS: The care of TB/HIV co-infected patients have shown sustained improvement in Vietnam. Rising numbers of MDR-TB cases is a concern, but this is not "driven" by HIV co-infection.


Assuntos
Coinfecção/epidemiologia , Infecções por HIV/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Antituberculosos/uso terapêutico , Coinfecção/tratamento farmacológico , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Vietnã/epidemiologia
3.
Int J Infect Dis ; 32: 170-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25809776

RESUMO

Tuberculosis (TB) is the leading opportunistic disease and cause of death in patients with HIV infection. In 2013 there were 1.1 million new TB/HIV co-infected cases globally, accounting for 12% of incident TB cases and 360,000 deaths. The Asia-Pacific region, which contributes more than a half of all TB cases worldwide, traditionally reports low TB/HIV co-infection rates. However, routine testing of TB patients for HIV infection is not universally implemented and the estimated prevalence of HIV in new TB cases increased to 6.3% in 2013. Although HIV infection rates have not seen the rapid rise observed in Sub-Saharan Africa, indications are that rates are increasing among specific high-risk groups. This paper reviews the risks of TB exposure and progression to disease, including the risk of TB recurrence, in this vulnerable population. There is urgency to scale up interventions such as intensified TB case-finding, isoniazid preventive therapy, and TB infection control, as well as HIV testing and improved access to antiretroviral treatment. Increased awareness and concerted action is required to reduce TB/HIV co-infection rates in the Asia-Pacific region and to improve the outcomes of people living with HIV.


Assuntos
Coinfecção/epidemiologia , Infecções por HIV/epidemiologia , Tuberculose/epidemiologia , Adulto , África Subsaariana , Ásia/epidemiologia , Criança , Progressão da Doença , Feminino , Infecções por HIV/complicações , Humanos , Masculino , Prevalência , Recidiva , Risco , Tuberculose/complicações
4.
Mol Syndromol ; 4(6): 257-66, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24167460

RESUMO

Lymphedema is caused by dysfunction of lymphatic vessels, leading to disabling swelling that occurs mostly on the extremities. Lymphedema can be either primary (congenital) or secondary (acquired). Familial primary lymphedema commonly segregates in an autosomal dominant or recessive manner. It can also occur in combination with other clinical features. Nine mutated genes have been identified in different isolated or syndromic forms of lymphedema. However, the prevalence of primary lymphedema that can be explained by these genetic alterations is unknown. In this study, we investigated 7 of these putative genes. We screened 78 index patients from families with inherited lymphedema for mutations in FLT4, GJC2, FOXC2, SOX18, GATA2, CCBE1, and PTPN14. Altogether, we discovered 28 mutations explaining 36% of the cases. Additionally, 149 patients with sporadic primary lymphedema were screened for FLT4, FOXC2, SOX18, CCBE1, and PTPN14. Twelve mutations were found that explain 8% of the cases. Still unidentified is the genetic cause of primary lymphedema in 64% of patients with a family history and 92% of sporadic cases. Identification of those genes is important for understanding of etiopathogenesis, stratification of treatments and generation of disease models. Interestingly, most of the proteins that are encoded by the genes mutated in primary lymphedema seem to act in a single functional pathway involving VEGFR3 signaling. This underscores the important role this pathway plays in lymphatic development and function and suggests that the unknown genes also have a role.

5.
HIV Med ; 14(2): 85-91, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22994529

RESUMO

OBJECTIVES: The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping. METHODS: Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype. RESULTS: No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA. CONCLUSIONS: The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.


Assuntos
Farmacorresistência Viral/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Inibidores de Integrase de HIV/farmacologia , Integrase de HIV/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Pirrolidinonas/farmacologia , Contagem de Linfócito CD4 , Farmacorresistência Viral/genética , Feminino , Genótipo , Infecções por HIV/genética , Infecções por HIV/imunologia , Integrase de HIV/genética , Integrase de HIV/imunologia , HIV-1/enzimologia , Humanos , Estudos Longitudinais , Masculino , RNA Viral , Raltegravir Potássico , Estudos Retrospectivos , Terapia de Salvação , Análise de Sequência de RNA , Falha de Tratamento , Carga Viral
6.
Clin Med (Lond) ; 11(3): 290-1, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21902089

RESUMO

This lesson describes an unusual case of a man who was recently diagnosed with type 1 diabetes and who presented with severe orthostatic hypotension. As his diabetes was recent in onset, well controlled, and he had no other signs of microvascular disease, other causes of orthostatic hypotension were sought. His serum and cerebrospinal fluid were strongly positive for Borrelia burgdorferi IgG, suggesting a diagnosis of Lyme neuroborreliosis. Autonomic instability in Lyme, while rare, has been previously reported.


Assuntos
Antibacterianos/uso terapêutico , Borrelia burgdorferi/isolamento & purificação , Ceftriaxona/uso terapêutico , Hipotensão Ortostática/microbiologia , Neuroborreliose de Lyme/complicações , Neuroborreliose de Lyme/tratamento farmacológico , Adulto , Animais , Borrelia burgdorferi/efeitos dos fármacos , Diabetes Mellitus Tipo 1/complicações , Neuropatias Diabéticas/complicações , Humanos , Hipotensão Ortostática/complicações , Hipotensão Ortostática/diagnóstico , Neuroborreliose de Lyme/diagnóstico , Masculino , Índice de Gravidade de Doença , Carrapatos , Resultado do Tratamento
7.
Insect Mol Biol ; 15(6): 721-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17201765

RESUMO

Malaria infection results in increased expression of immune responsive genes, including those encoding antimicrobial peptides such as Gambicin (Gam1) and Cecropin A (Cec1). Understanding how these genes are regulated will provide insights how the mosquito immune system is activated by Plasmodium. We previously have shown that Cec1 was primarily regulated by the Imd-Relish (REL2) pathway in the Anopheles gambiae Sua1B cell line. We show here that expression of Defensin A (Def1) and Gam1 was reduced after RNA interference against components of the Imd-REL2 pathway in An. gambiae cell lines. Interestingly, promoter reporters of these antimicrobial peptides were expressed at very low level in the cell line MSQ43 from Anopheles stephensi. Surprisingly, over-expression of either NF-kappaB transcription factor REL1 or REL2 alone is sufficient to induce the expression of Cec1, Gam1 and Def1. These results suggest that expression of these antimicrobial peptides (AMP) in vivo may be regulated by both the Toll and Imd pathways. We also show here for the first time that Tep4, a gene encoding a thioester containing protein, is regulated by REL2. Taken together, these results suggest that there are significant overlaps of genes regulated by the Toll-Rel1 and Imd-Rel2 pathways. Further, the different expression patterns in two different Anopheline cell lines provide a platform to identify other key positive and negative regulators of the antimicrobial peptide genes.


Assuntos
Anopheles/genética , Anopheles/imunologia , Imunidade/genética , Proteínas de Insetos/genética , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Linhagem Celular , Escherichia coli , Genes Reporter , Regiões Promotoras Genéticas/genética , Interferência de RNA , Transdução de Sinais
8.
Sci Total Environ ; 340(1-3): 213-30, 2005 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-15752503

RESUMO

During the period 1999-2002, five sampling cruises have been carried out on Lake Balaton to assess trace metal distribution in the lake and to identify major sources. Eighteen elements, including Cr, Co, Ni, Cu, Zn, Cd, Pb (trace metals) and Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr (major metals), were determined in one or more of the lake's compartments. Lower trace metal concentrations in rainwater were observed in June and February 2000, while much higher levels were present in September 2001 (during a storm event) and in snow (February 2000). In the Northern and Western parts of the lake, especially at the inflow of river Zala and the locations of the yacht harbours, metal concentrations were higher in almost all compartments. Because the lake is very shallow, storm conditions also change significantly the metal distributions in the dissolved and particulate phases. The Kis-Balaton protection system located on Zala river functions very efficiently for retaining suspended particulate matter (SPM; 72% retention) and associated metals. Metal concentrations in surface sediments of the lake showed a high variability. After normalisation for the fine sediment fraction, only a few stations including Zala mouth appeared to be enriched in trace metals. In zooplankton, Zn seemed to be much more elevated compared to the other trace metals. Based on the molar ratios of the trace metals in the various compartments and input flows of the lake, several trends could be deduced. For example, molar ratios of the trace metals in the dissolved and solid (suspended particulate matter and sediments) phases in the lake are fairly similar to those in Zala River.


Assuntos
Cadeia Alimentar , Metais Pesados/análise , Poluentes da Água/análise , Animais , Bivalves , Monitoramento Ambiental , Europa (Continente) , Sedimentos Geológicos/química , Metais Pesados/farmacocinética , Solubilidade , Poluentes da Água/farmacocinética , Abastecimento de Água , Zooplâncton
9.
Sci Total Environ ; 340(1-3): 231-46, 2005 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-15752504

RESUMO

The distribution and speciation of mercury in air, rain, lake water, sediment, and zooplankton in Lake Balaton (Hungary) were investigated between 1999 and 2002. In air, total gaseous mercury (TGM) ranged from 0.4 to 5.9 ng m(-3) and particulate phase mercury (PPM) from 0.01 to 0.39 ng m(-3). Higher concentrations of both TGM and PPM occurred during daytime. Higher concentrations of PPM occurred in winter. In rain and snow, total mercury ranged from 10.8 to 36.7 ng L(-1) in summer but levels up to 191 ng L(-1) in winter. Monomethylmercury (MMHg) concentrations ranged from 0.09 to 1.26 ng L(-1) and showed no seasonal variations. Total Hg in the unfiltered lake water varied spatially, with concentrations ranging from 1.4 to 6.5 ng L(-1). Approximately 70% of the total Hg is dissolved. MMHg levels ranged from 0.08 to 0.44 ng L(-1) as total and from 0.05 to 0.37 ng L(-1) in the dissolved form. Lower Hg concentrations in the water column occurred in winter. In suspended particulate matter and in sediment, total mercury ranged from 9 to 160 ng g(-1) dw, and MMHg ranged from 0.07 to 0.84 ng g(-1) dw. In zooplankton, an average mercury level of 31.0+/-6.8 ng g(-1) dw occurred, with MMHg accounting for approximately 17%. In sediments, suspended-matter- and zooplankton-high Hg and MMHg levels occurred at the mouth of the River Zala, but, in the lake, higher concentrations occurred on the Northern side, and an increasing trend from north-west to north-east was observed. In general, regarding Hg, Lake Balaton can be considered as a relatively uncontaminated site. The high-pH and well-oxygenated water as well as the low organic matter content of the sediment does not favour the methylation of Hg. In addition, bioconcentration and bioaccumulation factors are relatively low compared to other aquatic systems.


Assuntos
Poluentes Atmosféricos/análise , Mercúrio/análise , Poluentes da Água/análise , Poluentes Atmosféricos/química , Animais , Monitoramento Ambiental , Sedimentos Geológicos , Hungria , Mercúrio/química , Chuva , Zooplâncton
10.
Rev Pneumol Clin ; 60(5 Pt 1): 265-8, 2004 Nov.
Artigo em Francês | MEDLINE | ID: mdl-15687909

RESUMO

Isolated pulmonary nodules raise serious diagnostic problems. Combined imaging and endoscopic methods can often avoid exploratory thoracotomy. The situation is different however in developing countries where health facilities and technical availability are quite variable. Bronchial fibroscopy without image guidance can provide the diagnosis is an acceptable number of cases. We conducted a prospective study in 74 patients. After chest x-ray and CT scan of the lesion of interest, bronchial lavage was performed in each patient with brushings samples in 71 and transbronchial biopsy in 68. Riu staining was performed immediately in the endoscopy suite, providing an almost immediate diagnostic approach. The combination of lavage, brushing and biopsy provided a diagnostic yield as good as the brushings and biopsy combination. These endoscopic techniques gave the diagnosis of the specific lesion in 52 cases (70%). Most involved cancer but there were 15 cases of tuberculosis diagnosis, which remains frequent in developing countries.


Assuntos
Nódulo Pulmonar Solitário/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Vietnã
11.
Anal Bioanal Chem ; 377(2): 327-33, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12898107

RESUMO

A rapid and automated method for the determination of monomethylmercury (MMHg) in environmental samples was developed using headspace gas chromatography with atomic fluorescence detection in combination with aqueous phase ethylation. Sample preparation steps were optimized for sediments, biological samples, and water samples using certified reference materials and real samples with a broad range of MMHg concentrations. Different extraction procedures were compared for both sediments and biological samples. The methods were applied in the intercomparison exercises for the certification of MMHg in sediments (IAEA 405) and in Oyster tissue (BCR 710) and the results were accepted for certification. The detection limits for MMHg are 0.002 ng Hg/g for sediments and biological samples and 0.01 ng Hg/L for water samples. The method was tested for methylation artifacts; no artifact was observed in the sediment samples and CRMs tested.

12.
Int J Cancer ; 92(3): 457-62, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11291086

RESUMO

The incidence of cutaneous malignant melanoma (CMM) has been rising in fair-skinned populations throughout the world for decades. The upward trend may, however, finally be slowing in some of these populations. Recent (1983-1996) CMM incidence trends for a high incidence area (New South Wales, Australia) have been examined according to gender, age group, body site and tumour thickness. Despite continuing upward trends in older age groups, particularly among men (e.g., 7.20% increase per year in men aged 75+), incidence for younger ages is stabilizing (in men) or declining (in women): average annual percentage changes of -3.03 and -0.88 were observed for women aged 15-34 and 35-54, respectively. Patterns suggest a birth-cohort effect, with those born since 1945 or 1950 having lower (females) or similar (males) rates to those born earlier. For each gender, all-ages incidence rose by a similar amount for each of the main body sites except the leg in women, where incidence fell by 0.49% per year. In men, the incidence of both thin (75 mm) melanomas increased (significantly, by 2.63% per year and non-significantly, by 0.93% per year, respectively) between 1989 and 1996. In women, incidence remained stable for both thickness subgroups. These data are consistent with a stabilization or reduction in either total sun exposure or intermittency of exposure among New South Wales cohorts born since about 1950. Because incidence rates are still much higher than they were a few decades ago, however, efforts to reduce sun exposure, particularly in children and youth, must continue.


Assuntos
Melanoma/epidemiologia , Neoplasias Cutâneas/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Feminino , Humanos , Incidência , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , New South Wales/epidemiologia , Fatores Sexuais , Neoplasias Cutâneas/patologia
13.
J Cell Sci ; 112 ( Pt 12): 1813-24, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10341201

RESUMO

We depleted MAP4, a ubiquitously expressed microtubule (MT)-associated protein previously shown to be capable of stabilizing MTs, from HeLa cells by stably expressing antisense RNA. These HeLa-AS cells, in which the MAP4 level was decreased to 33% of the wild-type level, displayed decreased content of total tubulin (65% of the wild-type level). The partitioning of cellular tubulin into protomer and polymer was altered in HeLa-AS cells: polymeric tubulin was decreased to 46% of the level in control cells, while protomeric tubulin was increased to 226% of the level in control cells. Tubulin protein synthesis was decreased, consistent with the tubulin autoregulation model, which proposes that tubulin protomer inhibits its own synthesis. Following release from drug-induced depolymerization, MTs in HeLa-AS cells reformed more slowly, and showed an increased focus on the centrosome, as compared to control cells. HeLa-AS cells also appeared to be less bipolar in shape and flatter than control cells. Our data suggest that MAP4 regulates assembly level of MTs and, perhaps through this mechanism, is involved in controlling spreading and shape of cells.


Assuntos
Proteínas Associadas aos Microtúbulos/fisiologia , Tubulina (Proteína)/biossíntese , Biopolímeros , Células HeLa , Homeostase/fisiologia , Humanos , Ligação Proteica , Estrutura Terciária de Proteína
15.
J Am Diet Assoc ; 97(3): 258-61, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9060941

RESUMO

OBJECTIVE: To determine whether automation could accelerate the parenteral nutrition (PN) ordering and delivery process with concurrent improvements in the quality of nutrition therapy. DESIGN: The time required to order, process, and deliver PN orders and specific nutrient composition of the PN solution were collected prospectively for 2 weeks on all neonatal intensive care unit (NICU) patients receiving PN during both the manual phase (before automation) and computer phase of the study. SUBJECTS/SETTING: A total of 81 newborn infants in the NICU receiving PN for more than 5 days completed the study. STATISTICAL ANALYSES: Student's unpaired t test was used to evaluate differences between computer and manual methods for all outcome variables of interest. RESULTS: The time required to write and deliver PN orders was significantly lower using computer rather than manual methods (1.4 +/- 0.2 vs 4.5 +/- 0.5 minutes; P = .0001). Significant improvements in the nutrient composition of the PN solution resulted from use of computer ordering for energy (93.4 +/- 1.48 vs 79.2 +/- 1.8 kcal/kg per day; P = .0001), protein (2.92 +/- 0.02 vs 2.7 +/- 0.03 g protein per kilogram per day; P = .0001), calcium (2.3 +/- 0.1 vs 1.8 +/- 0.1 mEq/kg per day; P = .0005), and phosphate (1.3 +/- 0.06 vs 0.9 +/- 0.06 mM/kg per day; P = .0001). In addition, alkaline phosphatase levels improved (272 +/- 11 vs 404 +/- 25 U/L; P = .0001) and caloric and protein goals were achieved sooner (5.9 +/- 0.4 vs 8.7 +/- 0.8 days; P = .0045) when computer ordering rather than the manual method of ordering PN was used. IMPLICATIONS: Our findings indicate that automating the process of writing and delivering PN orders saved time because it eliminated repetitive tasks and tedious calculations previously required of neonatologists, dietitians, and pharmacists. Patient care in our population of neonates was enhanced by improving the nutrient content of the PN solution.


Assuntos
Sistemas de Informação em Farmácia Clínica , Unidades de Terapia Intensiva Neonatal/organização & administração , Nutrição Parenteral/normas , Prescrições , Software , Terapia Assistida por Computador , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal/normas , Sistemas de Medicação no Hospital , Fatores de Tempo , Virginia
16.
J Cell Sci ; 110 ( Pt 2): 281-94, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9044058

RESUMO

To investigate the in vivo functions of MAP4, a microtubule-associated protein expressed almost ubiquitously in vertebrate cells, we prepared stably transfected clonal mouse Ltk- cell lines expressing full-length MAP4 (L-MAP4 cells) or its MT-binding domain (L-MTB cells). Although transfectants showed no dramatic defect in morphology, organellar distribution, or level of MT polymer, as compared to naive Ltk- cells or L-MOCK cells (transfected with vector alone), MTs in L-MAP4 and L-MTB cells showed greater stability than those in control cells, as monitored by the level of post-translationally detyrosinated alpha-tubulin and by a quantitative nocodazole-resistance assay. In vivo, the MT-binding domain of MAP4 stabilized MTs less potently than full-length MAP4, in contrast to the equivalent efficacy demonstrated in studies of in vitro MT polymerization (Aizawa et al. (1991), J. Biol. Chem. 266, 9841-9846), L-MAP4 and L-MTB cells grew significantly more slowly than control cells; this growth inhibition was not due to mitotic arrest or cell death. L-MAP4 and L-MTB cells also exhibited greater tolerance to the MT-depolymerizing agent, nocodazole, but not to the MT-polymerizing agent, Taxol. Our results demonstrate that MAP4 and its MT-binding domain are capable of MT stabilization in vivo, and that increasing the intracellular level of MAP4 affects cell growth parameters.


Assuntos
Divisão Celular , Proteínas Associadas aos Microtúbulos/fisiologia , Microtúbulos/fisiologia , Animais , Expressão Gênica , Humanos , Células L , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Nocodazol/farmacologia , Transfecção
17.
J Cell Sci ; 110 ( Pt 24): 3055-64, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9365275

RESUMO

We previously prepared cell lines that inducibly overexpress MAP4, a microtubule (MT)-associated protein widely expressed in non-neuronal cells. Overexpression of either the full-length MAP4 molecule or its MT-binding domain, MTB, stabilized MTs and retarded cell growth, suggesting that overexpressed MAP4 impacts on MT-dependent functions in vivo. To test this hypothesis, we examined MT-based vesicle movements in living cells, using high resolution DIC microscopy. Overexpression of either MAP4 or MTB yielded a dose-dependent reduction in the frequency of MT-dependent organelle movements, relative to control cells. At steady state, both MAP4- and MTB-overexpressing cells showed unusual distributions of transferrin, LDL, dextran, and Golgi elements, as compared to control cells. MAP4 preferentially inhibited receptor-dependent uptake and degradation of LDL, and repositioning of Golgi elements after disruption by the drug, brefeldin A. L-MOCK cells treated with Taxol to stabilize the MTs to an extent equivalent to MAP4 overexpression did not show similar inhibition of vesicle motility or organellar trafficking, suggesting that deficits in organelle movements in vivo represent a direct effect of the presence of MAP4 or MTB, rather than an indirect effect of the stabilization of MTs by overexpressed MAP constructs. Our results show that MAP4 has the capacity to affect transport along MTs in vivo; these findings suggest a potential mechanism by which MAP4 could contribute to polarization or morphogenesis of cells.


Assuntos
Proteínas Associadas aos Microtúbulos/metabolismo , Organelas/fisiologia , Transporte Biológico , Brefeldina A , Linhagem Celular , Ciclopentanos/farmacologia , Proteínas Associadas aos Microtúbulos/genética , Organelas/efeitos dos fármacos , Organelas/metabolismo , Transferrina/metabolismo
18.
Virology ; 137(1): 41-8, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6089419

RESUMO

Sequence homology between the genomes of a hamster papovavirus (HaPV), polyoma virus (Py), and Simian virus 40 (SV40) has been studied by filter hybridization and electron microscopy under conditions of varying stringency. Hybrids between the HaPV and SV40 DNAs could be demonstrated only under nonstringent conditions. The region of highest homology was mapped in the early region of the SV40 genome. Extensive homology was detected between the genomes of HaPV and Py under stringent hybridization conditions, indicating at least 80% base matching in the regions of strongest sequence homology. These sequences were localized within both the early region and the late region of the Py genome. The homologous DNA segments mapped in the Py and the SV40 genomes are among the most strongly conserved regions in the polyoma (miopapova)-virus group.


Assuntos
Genes Virais , Papillomaviridae/genética , Polyomavirus/genética , Vírus 40 dos Símios/genética , Animais , Sequência de Bases , Cricetinae , Enzimas de Restrição do DNA , Mesocricetus , Microscopia Eletrônica , Conformação de Ácido Nucleico , Hibridização de Ácido Nucleico , Especificidade da Espécie
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