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1.
Exp Physiol ; 104(4): 469-475, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30758869

RESUMO

NEW FINDINGS: What is the topic of this review? We review the issues with using predicted resting metabolic rate equations in athletic populations. What advances does it highlight? The use of dated predicted resting metabolic rate equations is not appropriate for athletic populations until more studies have been conducted among these unique populations. ABSTRACT: Resting metabolic rate (RMR) is the amount of energy the body uses at rest. A suppressed RMR has been correlated with low energy availability and therefore used as an indicator of an individual's energy state. Furthermore, confounding identification of low energy availability within an athletic population are the physiological measures required, which can be time consuming and require professional expertise. To negate the demands of laboratory protocols in measuring RMR, predicted RMR (p RMR) equations were developed. Caution should be exercised when applying the p RMR equations for determining low energy availability in athletes owing to the population used to develop the equations and the higher metabolic cost of fat-free mass, thus elevated RMR, associated with athletes. Moreover, a low ratio of measured RMR to p RMR is often used as an alternative marker for energy deficiency. Predictive equations should implement fat-free mass within the algorithm when estimating RMR in athletic populations. The purpose of this paper is to describe p RMR equation development and the issues associated with use of p RMR equations for athletic populations. As professional sport increases, validation of p RMR equations in the modern athlete population is needed to monitor energy availability for athletic health and performance.


Assuntos
Metabolismo Basal/fisiologia , Metabolismo Energético/fisiologia , Esportes/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atletas , Composição Corporal/fisiologia , Índice de Massa Corporal , Calorimetria Indireta/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Colorectal Dis ; 21(2): 156-163, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30244521

RESUMO

AIM: Chronic immunosuppressant use increases the risk of septic complications after colectomy; however, adverse effects on other organ systems remain poorly understood. The aim of this study was to evaluate the multisystem organ effect(s) of chronic immunosuppressant(s) in colorectal cancer patients. METHODS: This was a retrospective study. The American College of Surgeons National Surgical Quality Improvement database (2005-2012) was queried. The primary end-points were 30-day mortality and 30-day morbidity after colectomy in patients on chronic immunosuppressant(s) compared to a non-immunosuppressant cohort. RESULTS: In total, 50 766 patients were identified, with 1203 (2.4%) taking chronic immunosuppressant(s). After propensity matching, 1197 patients in each cohort were evaluated with no differences seen in age, body mass index, male sex, wound classification, emergency case status, the presence of preoperative sepsis or operative time. On outcome analysis, 30-day mortality (5.7% vs 3.4%, P < 0.001) and 30-day overall morbidity (35.4% vs 29.0%, P = 0.001) were higher in patients on chronic immunosuppressant(s). Septic complications (10.6% vs 7.9%, P = 0.02) and surgical site infections (15.3% vs 12.3%, P = 0.03) were elevated with chronic immunosuppressant(s). There were no differences in cardiovascular, pulmonary, renal or neurological complications. Chronic immunosuppressant patients demonstrated longer total hospital stay (11.4 ± 11.7 vs 9.5 ± 9.4 days, P < 0.001) and postoperative length of stay (9.4 ± 9.2 vs 8.1 ± 7.6 days, P < 0.001). The limitation was that this was a retrospective study using a clinical dataset. CONCLUSION: In this study, immunosuppressant use is associated with worsened infective complications, without contributing to organ-specific complications following colectomy. Significant thought should be given to anastomosis vs stoma creation to possibly prevent worsened morbidity and mortality. Future study is required to determine specific pathways for risk reduction.


Assuntos
Colectomia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Complicações Pós-Operatórias/mortalidade , Sepse/mortalidade , Infecção da Ferida Cirúrgica/mortalidade , Idoso , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Complicações Pós-Operatórias/etiologia , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Sepse/etiologia , Infecção da Ferida Cirúrgica/etiologia , Estados Unidos
3.
J Econ Entomol ; 107(2): 797-805, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24772563

RESUMO

Dillapiol, the main constituent in dill Anethum sowa Roxb. ex Fleming (Apiaceae) oil and wild pepper, Piper aduncum L. (Piperaceae), is an effective cytochrome P450 inhibitor similar to piperonylbutoxide (PBO). Laboratory and field trials with pyrethrum Chrysanthemum cinerariifolium (Trevir.) vis. extracts combined with dillapiol (1:5 and 1:16 ratio) were effective against both insecticide-susceptible and -resistant Colorado potato beetle Leptinotarsa decemlineata (Say). In the laboratory, pyrethrum efficacy was increased 2.2-fold with the SS strain and 9.1-fold with the RS strains by using pyrethrum + dillapiol. Two field trials with the pyrethrum + dillapiol formulation demonstrated efficacy > or = 10 times than that of pyrethrum alone. The residual activity (half-life) of the combination exposed to direct sunlight was 3 h but it increased to 10.7 h by adding 2% of the sunscreen octylmethoxycinnamate.


Assuntos
Besouros , Dioxóis , Inseticidas , Sinergistas de Praguicidas , Piretrinas , Compostos Alílicos , Animais , Besouros/crescimento & desenvolvimento , Meia-Vida , Controle de Insetos , Resistência a Inseticidas , Larva/crescimento & desenvolvimento
4.
J Econ Entomol ; 104(5): 1680-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22066199

RESUMO

Two mineral oils and 12 linear primary alcohols were studied, alone and in combination, to determine their contact toxicity to adult German cockroaches, Blattella germanica (L.) (Dictyoptera: Blattellidae). The more toxic oil, PD23 (LD50 = 1.45 mg per cockroach) was used for combination studies. Alcohols with carbon chain lengths of C3 and C8 through C12 were the most toxic, with LD50 values ranging from 0.3 to 0.6 mg. C1 (methanol) and C14 (1-tetradecanol) were least toxic, with LD50 values of 2.35 and 1.75 mg, respectively. Eight of the 12 combinations of a nonlethal dose of PD23 oil with an LD10 dose of alcohol produced significantly greater mortality than predicted under the assumption of additive effects. A sample of five synergistic oil + alcohol combinations, covering most of the alcohol carbon chain length range over which synergy occurred, was further studied by calculating LD50 values for three fixed mixture ratios (80:20, 50:50, and 20:80) of each combination. Results were analyzed using both graphical techniques (isobole analysis) and by nonlinear regression. At least one, but not necessarily all, of the three fixed ratio combinations of each oil + alcohol pairing indicated synergy. The conclusions drawn from the isobole and regression analyses were consistent.


Assuntos
Álcoois/toxicidade , Blattellidae/efeitos dos fármacos , Óleo Mineral/toxicidade , Álcoois/química , Animais , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Dose Letal Mediana , Masculino , Óleo Mineral/química , Dinâmica não Linear , Análise de Regressão , Testes de Toxicidade Aguda
5.
Nature ; 429(6990): 375-81, 2004 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-15164054

RESUMO

The finished sequence of human chromosome 10 comprises a total of 131,666,441 base pairs. It represents 99.4% of the euchromatic DNA and includes one megabase of heterochromatic sequence within the pericentromeric region of the short and long arm of the chromosome. Sequence annotation revealed 1,357 genes, of which 816 are protein coding, and 430 are pseudogenes. We observed widespread occurrence of overlapping coding genes (either strand) and identified 67 antisense transcripts. Our analysis suggests that both inter- and intrachromosomal segmental duplications have impacted on the gene count on chromosome 10. Multispecies comparative analysis indicated that we can readily annotate the protein-coding genes with current resources. We estimate that over 95% of all coding exons were identified in this study. Assessment of single base changes between the human chromosome 10 and chimpanzee sequence revealed nonsense mutations in only 21 coding genes with respect to the human sequence.


Assuntos
Cromossomos Humanos Par 10/genética , Genes , Mapeamento Físico do Cromossomo , Animais , Composição de Bases , Mapeamento de Sequências Contíguas , Ilhas de CpG/genética , Evolução Molecular , Éxons/genética , Duplicação Gênica , Variação Genética/genética , Genética Médica , Genômica , Humanos , Pan troglodytes/genética , Proteínas/genética , Pseudogenes/genética , Análise de Sequência de DNA
6.
Nature ; 425(6960): 805-11, 2003 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-14574404

RESUMO

Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.


Assuntos
Cromossomos Humanos Par 6/genética , Genes/genética , Mapeamento Físico do Cromossomo , Animais , Éxons/genética , Doenças Genéticas Inatas/genética , Antígenos HLA-B/genética , Humanos , Pseudogenes/genética , RNA de Transferência/genética , Análise de Sequência de DNA
7.
Science ; 198(4320): 958-60, 1977 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-929182

RESUMO

Thin sections of longitudinal and circular muscle of myometrium obtained from rats during pregnancy, at term, during delivery, and postpartum were quantitatively examined in the electron microscope. Gap junctions (low resistance pathways) were only present during or immediately prior to delivery and immediately postpartum. The absence of gap junctions during gestation may be necessary for maintenance of pregnancy, while their occurrence during parturition may lead to effective termination of pregnancy.


Assuntos
Junções Intercelulares/ultraestrutura , Trabalho de Parto , Miométrio/ultraestrutura , Prenhez , Útero/ultraestrutura , Animais , Feminino , Idade Gestacional , Gravidez , Progesterona/fisiologia , Ratos
8.
Science ; 239(4836): 190-3, 1988 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-2827305

RESUMO

The beta-adrenergic agonist isoproterenol and analogs of adenosine 3',5'-monophosphate (cAMP) induced a potassium current, M current, in freshly dissociated gastric smooth muscle cells. Muscarinic agonists suppress this current, apparently by acting at a locus downstream from regulation of cAMP levels by adenylate cyclase and phosphodiesterase. Thus, M current can be induced by an agent and regulated in antagonistic fashion by beta-adrenergic and muscarinic systems.


Assuntos
Músculo Liso/fisiologia , Potássio/fisiologia , Receptores Adrenérgicos beta/fisiologia , Receptores Muscarínicos/fisiologia , Acetilcolina/farmacologia , Animais , Bufo marinus , AMP Cíclico/fisiologia , Condutividade Elétrica , Técnicas In Vitro , Isoproterenol/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Muscarina/farmacologia , Estômago/fisiologia
9.
J Clin Invest ; 86(5): 1664-70, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2243138

RESUMO

Cytoplasmic protein from peripheral blood myeloid cells of chronic myelogenous leukemia (CML) patients altered the electrophoretic mobility of complexes formed between nuclear proteins and interferon-inducible transcriptional enhancers. Immature myeloid marrow cells (blasts and promyelocytes) have a higher level of this activity than do mature myeloid marrow cells (bands and polys). This activity, which is not detectable in the peripheral blood cells of normal individuals, is at least 50-fold higher in CML marrow blasts and promyelocytes than that found in marrow blasts and promyelocytes of normal individuals. This activity was inhibited by in vivo incubation of immature myeloid cells with the phosphatase inhibitor, sodium orthovanadate (0.2 mM), and by adding orthovanadate (20 mM) directly to cytoplasmic proteins of myeloid cells. Interferon-alpha (1,000 U/ml) reduced the effects of the CML myeloid cell cytoplasmic protein on the electrophoretic mobility of nuclear protein-DNA complexes. These data suggest that a unique phosphatase may be involved in the abnormalities in CML which are modulated by interferon-alpha.


Assuntos
Fosfatase Ácida/sangue , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica , Interferon Tipo I/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Proteínas Nucleares/metabolismo , Sequência de Bases , Medula Óssea/patologia , Eletroforese , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Dados de Sequência Molecular , Temperatura , Transcrição Gênica
10.
Mol Cell Biol ; 13(1): 690-702, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7678055

RESUMO

We have cloned and functionally characterized the human interferon regulatory factor 1 (IRF-1) gene promoter. The promoter contains a CpG island, with several GC boxes, a CAAT box, but no TATA box. IRF-1 mRNA is strongly induced by gamma interferon (IFN-gamma) but more weakly and transiently by IFN-alpha. There are several putative kappa B motifs and numerous AA(G/A)G(G/T)A and GAAANN motifs throughout the promoter. The IRF-1 promoter is not autoregulated by the IRF-1 gene product. IFN inducibility of the promoter was studied with 5' deletion mutants linked to a heterologous reporter gene. Gel mobility shift assays were used to show IFN-inducible factor binding to the IRF-1 promoter. These studies showed that IFN inducibility is conferred by a novel imperfect inverted-repeat arrangement of two GAAANN motifs within a domain, 130 nucleotides upstream of transcription initiation. This inverted repeat binds a factor upon induction with IFN and can confer IFN inducibility on a heterologous promoter. Conversely, point mutations of the inverted repeat are not IFN inducible when linked to the same heterologous promoter.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Interferons/farmacologia , Fosfoproteínas/genética , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica/efeitos dos fármacos , Genes , Humanos , Fator Regulador 1 de Interferon , Dados de Sequência Molecular , NF-kappa B/metabolismo , Oligodesoxirribonucleotídeos/química , RNA Mensageiro/genética , Homologia de Sequência do Ácido Nucleico
11.
Bone Joint J ; 99-B(11): 1520-1525, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29092993

RESUMO

AIMS: To evaluate the effect of a single early high-dose vitamin D supplement on fracture union in patients with hypovitaminosis D and a long bone fracture. PATIENTS AND METHODS: Between July 2011 and August 2013, 113 adults with a long bone fracture were enrolled in a prospective randomised double-blind placebo-controlled trial. Their serum vitamin D levels were measured and a total of 100 patients were found to be vitamin D deficient (< 20 ng/ml) or insufficient (< 30 ng/mL). These were then randomised to receive a single dose of vitamin D3 orally (100 000 IU) within two weeks of injury (treatment group, n = 50) or a placebo (control group, n = 50). We recorded patient demographics, fracture location and treatment, vitamin D level, time to fracture union and complications, including vitamin D toxicity. Outcomes included union, nonunion or complication requiring an early, unplanned secondary procedure. Patients without an outcome at 15 months and no scheduled follow-up were considered lost to follow-up. The t-test and cross tabulations verified the adequacy of randomisation. An intention-to-treat analysis was carried out. RESULTS: In all, 100 (89%) patients had hypovitaminosis D. Both treatment and control groups had similar demographics and injury characteristics. The initial median vitamin D levels were 16 ng/mL (interquartile range 5 to 28) in both groups (p = 0.885). A total of 14 patients were lost to follow-up (seven from each group), two had fixation failure (one in each group) and one control group patient developed an infection. Overall, the nonunion rate was 4% (two per group). No patient showed signs of clinical toxicity from their supplement. CONCLUSIONS: Despite finding a high level of hypovitaminosis D, the rate of union was high and independent of supplementation with vitamin D3. Cite this article: Bone Joint J 2017;99-B:1520-5.


Assuntos
Colecalciferol/uso terapêutico , Fixação de Fratura , Fraturas Ósseas/cirurgia , Fraturas não Consolidadas/prevenção & controle , Deficiência de Vitamina D/tratamento farmacológico , Vitaminas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Esquema de Medicação , Feminino , Seguimentos , Fraturas Ósseas/complicações , Fraturas não Consolidadas/epidemiologia , Fraturas não Consolidadas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/diagnóstico
12.
Circ Res ; 89(6): 517-25, 2001 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11557739

RESUMO

Vascular smooth muscle cells (SMCs) perform diverse functions and this functional heterogeneity could be based on differential recruitment of distinct SMC subsets. In humans, however, there is little support for such a paradigm, partly because isolation of pure human SMC subsets has proven difficult. We report the cloning of 12 SMC lines from a single fragment of human internal thoracic artery and the elucidation of 2 distinct cellular profiles. Epithelioid clones (n=9) were polygonal at confluence, 105+/-9 micrometer in length, and had a doubling time of 39+/-2 hours. Spindle-shaped clones (n=3) were larger (267+/-18 micrometer long, P<0.01) and grew slower (doubling time 65+/-4 hours, P<0.01). Both types of clones expressed smooth muscle (SM) alpha-actin, SM-myosin heavy chains, h-caldesmon, and calponin, but only spindle-shaped clones expressed metavinculin. Epithelioid clones displayed greater proliferation in response to platelet-derived growth factor-BB and fibroblast growth factor-2 and were more responsive to the migratory effect of platelet-derived growth factor-BB. Spindle-shaped clones showed more robust Ca(2+) transients in response to angiotensin II, histamine, and norepinephrine, crawled more quickly, and expressed more type I collagen. On serum withdrawal, spindle-shaped clones differentiated into a contraction-competent cell. A regional basis for diversity among SMCs was suggested by stepwise arterial digestion, which liberated small, SM alpha-actin-positive cells from the abluminal medial layers and larger SMCs from all layers. These results identify inherent SMC diversity in the media of the adult internal thoracic artery and suggest differential participation of SMC subsets in the regulation of human arterial behavior.


Assuntos
Artéria Torácica Interna/citologia , Músculo Liso Vascular/citologia , Actinas/metabolismo , Adulto , Angiotensina II/farmacologia , Becaplermina , Western Blotting , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Células Clonais , Meios de Cultura/farmacologia , DNA Complementar/genética , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Cariotipagem , Proteínas dos Microfilamentos , Músculo Liso Vascular/química , Músculo Liso Vascular/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Fenótipo , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Proto-Oncogênicas c-sis , Fatores de Tempo , Calponinas
13.
J Bone Joint Surg Br ; 88(12): 1613-7, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17159174

RESUMO

Our study was designed to compare the effect of indometacin with that of a placebo in reducing the incidence of heterotopic ossification in a prospective, randomised trial. A total of 121 patients with displaced fractures of the acetabulum treated by operation through a Kocher-Langenbeck approach was randomised to receive either indometacin (75 mg) sustained release, or a placebo once daily for six weeks. The extent of heterotopic ossification was evaluated on plain radiographs three months after operation. Significant ossification of Brooker grade III to IV occurred in nine of 59 patients (15.2%) in the indometacin group and 12 of 62 (19.4%) receiving the placebo. We were unable to demonstrate a statistically significant reduction in the incidence of severe heterotopic ossification with the use of indometacin when compared with a placebo (p = 0.722). Based on these results we cannot recommend the routine use of indometacin for prophylaxis against heterotopic ossification after isolated fractures of the acetabulum.


Assuntos
Acetábulo/lesões , Anti-Inflamatórios não Esteroides/uso terapêutico , Fraturas Ósseas/cirurgia , Indometacina/uso terapêutico , Ossificação Heterotópica/prevenção & controle , Adolescente , Adulto , Idoso , Anti-Inflamatórios não Esteroides/sangue , Método Duplo-Cego , Feminino , Humanos , Indometacina/sangue , Masculino , Pessoa de Meia-Idade , Ossificação Heterotópica/etiologia , Cooperação do Paciente , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
14.
Methods Inf Med ; 45(3): 246-52, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16685332

RESUMO

OBJECTIVE: To characterize the difficulty confronting investigators in removing protected health information (PHI) from cross-discipline, free-text clinical notes, an important challenge to clinical informatics research as recalibrated by the introduction of the US Health Insurance Portability and Accountability Act (HIPAA) and similar regulations. METHODS: Randomized selection of clinical narratives from complete admissions written by diverse providers, reviewed using a two-tiered rater system and simple automated regular expression tools. For manual review, two independent reviewers used simple search and replace algorithms and visual scanning to find PHI as defined by HIPAA, followed by an independent second review to detect any missed PHI. Simple automated review was also performed for the "easy" PHI that are number- or date-based. RESULTS: From 262 notes, 2074 PHI, or 7.9 +/- 6.1 per note, were found. The average recall (or sensitivity) was 95.9% while precision was 99.6% for single reviewers. Agreement between individual reviewers was strong (ICC = 0.99), although some asymmetry in errors was seen between reviewers (p = 0.001). The automated technique had better recall (98.5%) but worse precision (88.4%) for its subset of identifiers. Manually de-identifying a note took 87.3 +/- 61 seconds on average. CONCLUSIONS: Manual de-identification of free-text notes is tedious and time-consuming, but even simple PHI is difficult to automatically identify with the exactitude required under HIPAA.


Assuntos
Confidencialidade , Registro Médico Coordenado , Narração , Custos e Análise de Custo , Health Insurance Portability and Accountability Act , Humanos , Processamento de Linguagem Natural , Estados Unidos , Utah
15.
J Gen Physiol ; 80(3): 353-75, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7142952

RESUMO

We have studied some passive electrical properties of uterine smooth muscle to determine whether a change in electrical parameters accompanies gap junction formation at delivery. The length constant of the longitudinal myometrium increased from 2.6 +/- 0.8 mm (X +/- SD) before term to 3.7 +/- 1 mm in tissues from delivering animals. The basis of the change was a 33% decrease in internal resistance and a 46% increase in membrane resistance. Axial current flow in an electrical syncytium such as myometrium is impeded by the cytoplasm of individual cells plus the junctions between cells. Measurement of the longitudinal impedance indicated that the specific resistance of the myoplasmic component was constant at 319 +/- 113 omega . cm before term and 340 +/- 93 omega . cm at delivery. However, a decrease in junctional resistance was apparent from 323 +/- 161 omega . cm to 134 +/- 64 omega . cm at delivery. 1.5-2 d after delivery, the junctional resistance was increased, as was the myoplasmic resistance. Thin-section electron microscopy of some of the same muscle samples showed that gap junctions were present in significantly greater numbers in the delivering tissues. Therefore, our results support the hypothesis that gap junction formation at delivery is associated with improved electrical coupling of uterine smooth muscle.


Assuntos
Miométrio/fisiologia , Contração Uterina , Útero/fisiologia , Potenciais de Ação , Animais , Condutividade Elétrica , Estimulação Elétrica , Feminino , Junções Intercelulares/fisiologia , Trabalho de Parto , Microscopia Eletrônica , Miométrio/ultraestrutura , Gravidez , Ratos , Ratos Endogâmicos
16.
Cytogenet Genome Res ; 111(2): 110-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16103651

RESUMO

Major histocompatibility complex (MHC) molecules are central to development and regulation of the immune system in all jawed vertebrates. MHC class III cytokine genes from the tumor necrosis factor core family, including tumor necrosis factor (TNF) and lymphotoxin alpha and beta (LTA, LTB), are well studied in human and mouse. Orthologues have been identified in several other eutherian species and the cDNA sequences have been reported for a model marsupial, the tammar wallaby. Comparative genomics can help to determine gene function, to understand the evolution of a gene or gene family, and to identify potential regulatory regions. We therefore cloned the genomic region containing the tammar LTB, TNF, and LTA orthologues by "genome walking", using primers designed from known tammar sequences and regions conserved in other species. We isolated two tammar BAC clones containing all three genes. These tammar genes show similar intergenic distances and the same transcriptional orientation as in human and mouse. Gene structures and sequences are also very conserved. By comparing the tammar, human and mouse genomic sequences we were able to identify candidate regulatory regions for these genes in mammals. Full length sequencing of BACs containing the three genes has been partially completed, and reveals the presence of a number of other tammar MHC III orthologues in this region.


Assuntos
Macropodidae/genética , Complexo Principal de Histocompatibilidade , Animais , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Artificiais Bacterianos , Cromossomos de Mamíferos , Clonagem Molecular , Sequência Conservada , Primers do DNA , Genoma , Humanos , Macropodidae/imunologia , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica , Fator de Necrose Tumoral alfa/genética
17.
J Parasitol ; 101(3): 390-2, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25710628

RESUMO

Toxoplasma gondii is a protozoal parasite with worldwide distribution that is able to infect a wide variety of mammals and birds. Our main goal was to screen for T. gondii antibody titers in a previously untested species, the spotted hyena ( Crocuta crocuta); however, this goal first required us to investigate serological procedures that could be suitable for hyenas. Cats are the closest domestic relations of hyenas, so T. gondii antibody titers were first compared in 26 feral cats with specific or nonspecific fluorophore-labeled secondary reagents, i.e., anti-cat IgG or protein A. Substitution of anti-cat IgG with protein A caused a statistically significant drop in titer measurements in cats (P = 0.01) with a reduction of the geometric mean titer equivalent to 1 doubling-dilution. The same procedures were then applied to captive spotted hyenas. Titers measured in 9 of 10 hyenas were identical whether anti-cat IgG or protein A was used as the secondary reagent: 5 had titers <1:16, 2 had titers of 1:16, and 2 had titers of 1:32. One hyena had maximum titers of 1:64 or 1:32 when anti-cat IgG or protein A was used, respectively. The use of protein A as the secondary reagent in serologic assays can be applied to a range of mammalian species and seems unlikely to affect test specificity; however, the use of protein A may reduce test sensitivity, as suggested in the present study using cats. Despite a control program, some exposure to T. gondii had occurred in the Zoo's spotted hyenas.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Gato/parasitologia , Hyaenidae/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/parasitologia , Animais , Doenças do Gato/imunologia , Gatos , Ensaio de Imunoadsorção Enzimática/veterinária , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Especificidade de Hospedeiro , Soros Imunes , Imunoglobulina G , Sensibilidade e Especificidade , Proteína Estafilocócica A , Toxoplasmose Animal/imunologia
18.
J Bone Miner Res ; 13(4): 688-94, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9556069

RESUMO

Wortmannin (WT) and 17beta-hydroxywortmannin (HWT), which are inhibitors of phosphatidylinositol-3(OH)-kinase (PI3K), have been shown previously to inhibit bone resorption in vitro and in vivo, possibly by interfering with formation of the osteoclast ruffled border. Since migration of osteoclasts also plays an important role in the process of bone resorption, we investigated the effects of these inhibitors on osteoclast morphology and motility. Both HWT and WT caused a sustained decrease in the planar area of osteoclasts in vitro (half maximal effect at 25 and 165 nM, respectively), with the effect of HWT on cell area more readily reversible than WT. These agents also caused accumulation of intracellular vesicles. Time-lapse video microscopy was used to record the migration of osteoclasts in response to macrophage colony-stimulating factor (M-CSF) or vehicle, flowing passively from a micropipette positioned 200-400 microm from the cell. M-CSF caused directed migration of osteoclasts, indicating chemotaxis (over 3 h osteoclasts migrated 96 +/- 14 microm in response to M-CSF vs. 11 +/- 2 microm in control experiments). Both WT (100 or 500 nM) and LY294002 (100 microM), a specific PI3K inhibitor structurally unrelated to WT, significantly inhibited osteoclast chemotaxis in response to M-CSF. Taken together, these effects of WT, HWT, and LY294002 are consistent with an important role for PI3K in regulating cytoskeletal function in osteoclasts. The inhibitory effects of WT and HWT on bone resorption may be due, in part, to impairment of osteoclast motility.


Assuntos
Androstadienos/farmacologia , Quimiotaxia/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Animais , Reabsorção Óssea/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Cromonas/farmacologia , Fêmur/citologia , Fator Estimulador de Colônias de Macrófagos/farmacologia , Microscopia de Vídeo , Morfolinas/farmacologia , Osteoclastos/fisiologia , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Tíbia/citologia , Wortmanina
19.
J Bone Miner Res ; 16(7): 1237-47, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11450699

RESUMO

Transforming growth factor-beta (TGF-beta) is released from the matrix during bone resorption and has been implicated in the pathogenesis of giant cell tumors of bone and the expansion of breast cancer metastases in bone. Because osteoclasts mediate tumor-induced osteolysis, we investigated whether TGF-beta stimulates osteoclast recruitment. Osteoclasts were isolated from rat long bones and time-lapse video microscopy was used to monitor their morphology and motility. Within 5 minutes, TGF-beta (0.1 nM) induced dynamic ruffling, with 65% of osteoclasts displaying membrane ruffles compared with 35% in untreated controls. Over a 2-h period, osteoclasts exhibited significant directed migration toward a source of TGF-beta, indicating chemotaxis. echistatin, an alphavbeta3 integrin blocker that inhibits macrophage colony-stimulating factor (M-CSF)-induced osteoclast migration, did not prevent the migration of osteoclasts toward TGF-beta. In contrast, a beta1 integrin blocking antibody inhibited osteoclast chemotaxis toward TGF-beta but not M-CSF. These data indicate the selective use of integrins by osteoclasts migrating in response to different chemotaxins. In addition, wortmannin and U0126 inhibited TGF-beta-induced chemotaxis, suggesting involvement of the phosphatidylinositol 3 (PI 3) kinase and mitogen-activated protein (MAP) kinase signaling pathways. Physiologically, TGF-beta, may coordinate osteoclast activity by recruiting osteoclasts to existing sites of resorption. Pathologically, TGF-beta-induced osteoclast recruitment may be critical for expansion of primary and metastatic tumors in bone.


Assuntos
Membrana Celular/efeitos dos fármacos , Extensões da Superfície Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia , Androstadienos/farmacologia , Animais , Butadienos/farmacologia , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Fêmur/citologia , Fêmur/efeitos dos fármacos , Integrinas/antagonistas & inibidores , Integrinas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Fator Estimulador de Colônias de Macrófagos/farmacologia , Microscopia de Vídeo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Nitrilas/farmacologia , Osteoclastos/enzimologia , Peptídeos/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Tíbia/citologia , Tíbia/efeitos dos fármacos , Wortmanina
20.
J Bone Miner Res ; 9(11): 1769-76, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7863828

RESUMO

We demonstrated previously that platelet-activating factor (PAF), a potent inflammatory mediator, acts on osteoclasts to elevate cytosolic [Ca2+] and stimulate resorption. However, it is not clear whether the effects of PAF on resorptive activity are direct or indirect. In the present study, we investigated the effects of PAF on osteoclast motility. Osteoclasts were isolated from the long bones of neonatal rabbits, and cell motility and morphology were monitored using time-lapse video microscopy. Calcitonin, a hormone known to induce retraction of pseudopods and inhibit resorptive activity, was used to render osteoclasts quiescent. Within 10 minutes of calcitonin treatment (100 ng/ml, final), pronounced retraction of pseudopods was observed in 68 of 112 cells tested. When PAF (200 nM, final) was added 10 minutes after calcitonin treatment, pseudopods were evident 1 h later in 15 of 37 calcitonin-responsive cells tested. In contrast, pseudopods were evident in only 4 of 31 calcitonin-responsive cells treated with control solutions (PAF-vehicle or S-PAF, the biologically inactive stereoisomer of PAF). Pseudopod formation was quantified by measuring the planar area of pseudopods with a computer-based video analysis system. When assessed 60 minutes following PAF treatment, the pseudopod area was significantly greater in PAF-treated cells than in control cells. In some calcitonin-treated osteoclasts, PAF induced pseudopod formation when applied focally using an extracellular micropipette, consistent with a direct action of PAF. We conclude that PAF directly induces pseudopod formation in calcitonin-inhibited osteoclasts, a morphologic response indicative of osteoclast activation.


Assuntos
Calcitonina/farmacologia , Cálcio/metabolismo , Osteoclastos/efeitos dos fármacos , Fator de Ativação de Plaquetas/toxicidade , Animais , Animais Recém-Nascidos , Reabsorção Óssea/tratamento farmacológico , Calcitonina/uso terapêutico , Movimento Celular/efeitos dos fármacos , Distribuição de Qui-Quadrado , Processamento de Imagem Assistida por Computador , Osteoclastos/ultraestrutura , Coelhos , Estereoisomerismo , Gravação em Vídeo
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