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1.
Int J Obstet Anesth ; 56: 103930, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37804553

RESUMO

INTRODUCTION: Subspecialty training in obstetric anesthesiology is associated with improved patient outcomes and reduced anesthesia-related morbidity and mortality. Despite this, the demand for fellowship-trained obstetric anesthesiologists far exceeds the supply. This survey study aimed to evaluate the perceived value of obstetric anesthesiology subspecialty training on career trajectory, job satisfaction, quality of life, and job autonomy. METHODS: After Institutional Review Board approval, we conducted a cross-sectional study of fellowship-trained obstetric anesthesiologists in the United States of America. In March and April 2022, program directors of obstetric anesthesiology fellowships distributed an electronic survey link containing 29 multiple-choice questions to their program alumni. Survey content included respondent demographic characteristics, practice models, career information, and perceived value of an obstetric anesthesiology fellowship. RESULTS: We surveyed 217/502 (43%) fellowship-trained obstetric anesthesiologists with a response rate of 158/217 (73%). Most worked in urban, academic, and level IV perinatal health centers. The majority believed an obstetric anesthesiology fellowship was "extremely beneficial" (77%), enhanced quality of life (84%), improved the quality of patient care (99%), and was influential in helping obtain their first post-training job (86%). The perceived value of the fellowship included an enhanced career trajectory, a sense of purpose, improved job satisfaction, a sense of work community, lower burnout, involvement in maternal health initiatives, increased mentorship, and departmental leadership. CONCLUSION: In this survey study, fellowship-trained obstetric anesthesiologists perceived a positive impact of fellowship training on career trajectory, job protection and autonomy, quality of life, and job satisfaction. This information may be meaningful to trainees considering pursuing a fellowship and a career in obstetric anesthesiology.


Assuntos
Anestesiologia , Internato e Residência , Feminino , Gravidez , Humanos , Estados Unidos , Anestesiologia/educação , Anestesiologistas , Bolsas de Estudo , Estudos Transversais , Qualidade de Vida , Inquéritos e Questionários
2.
J Appl Microbiol ; 131(1): 135-145, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33251637

RESUMO

AIMS: The study was aimed to evaluate the antibacterial activity and efficacy of chestnut and quebracho wood extracts against Salmonella by in vitro assays and in vivo trials. METHODS AND RESULTS: The extracts showed inhibitory activity against Salmonella determined by the minimum inhibitory concentration method as well as on the adhesion and invasion of S. Gallinarum (SG) and S. Enteritidis (SE) in Caco-2 cells. Also, transmission electron microscopy revealed that extract-treated Salmonella showed disruption of cell walls and membranes, damage of the cytoplasm and tannin-protein aggregations. In addition, efficacy of the extracts to control SG and SE was evaluated in experimental infection trials in laying hens and broilers respectively. SE excretion was significantly reduced on days 5 (P < 0·01) and 12 (P < 0·025) only in the quebracho group. In the fowl typhoid infection model, hens that received the chestnut extract showed a significantly reduced mortality (P < 0·05). CONCLUSIONS: Our results evidence that these alternative natural products may be a useful tool to control Salmonella in poultry. SIGNIFICANCE AND IMPACT OF THE STUDY: Salmonella is a zoonotic pathogen usually associated with poultry production. This study provides information about the mechanism of antibacterial effects of chestnut and quebracho wood extracts to control Salmonella in poultry.


Assuntos
Galinhas/microbiologia , Extratos Vegetais/farmacologia , Salmonelose Animal/prevenção & controle , Salmonella/efeitos dos fármacos , Taninos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Membrana Externa Bacteriana/efeitos dos fármacos , Células CACO-2 , Parede Celular/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Doenças das Aves Domésticas/microbiologia , Madeira/química
3.
Int J Obstet Anesth ; 44: 77-80, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32810652

RESUMO

Patients who suffer an unintentional dural puncture have a high risk of developing a post-dural puncture headache. Other neurologic complications have been reported, but seizure is rarely seen. We present a case of a 21-year-old primigravida who experienced an unrecognized unintentional dural puncture that ultimately resulted in a tonic-clonic seizure from intracranial hypotension one week following the dural breach. Her trachea was intubated and she was transferred to the intensive care unit. Two epidural blood patches, performed by neuroradiologists, were needed before the patient experienced complete resolution of her headache. During the re-admission, she also experienced a pulmonary embolus which further lengthened her hospital stay.


Assuntos
Analgesia Epidural/efeitos adversos , Anestesia Obstétrica/efeitos adversos , Hipotensão Intracraniana/complicações , Cefaleia Pós-Punção Dural/etiologia , Convulsões/etiologia , Punção Espinal/efeitos adversos , Adulto , Placa de Sangue Epidural/métodos , Feminino , Humanos , Hipotensão Intracraniana/terapia , Cefaleia Pós-Punção Dural/terapia , Gravidez , Convulsões/terapia , Adulto Jovem
6.
Biomed Res Int ; 2016: 3278359, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27747227

RESUMO

Necrotic enteritis (NE) is an important concern in poultry industry since it causes economic losses, increased mortality, reduction of bird welfare, and contamination of chicken products for human consumption. For decades, the use of in-feed antimicrobial growth promoters (AGPs) has been the main strategy to control intestinal pathogens including Clostridium perfringens (CP), the causative agent of NE. However, the use of AGPs in animal diet has been linked to the emergence and transmission of antimicrobial resistance through food-borne microorganisms, which has led to the ban of AGPs in many countries. This scenario has challenged the poultry industry to search for safer alternative products in order to prevent NE. In this context, the utilization of natural plant extracts with antimicrobial properties appears as a promising and feasible tool to control NE in chicken. In this paper, we review the scientific studies analyzing the potential of plant extracts as alternative feed additives to reduce NE in poultry, with focus on two types of plant products that arise as promising candidates: tannins and essential oils. Some of these products showed antimicrobial activity against CP and coccidia in vitro and in vivo and are able to increase productive performance, emulating the bioactive properties of AGPs.


Assuntos
Anti-Infecciosos/uso terapêutico , Infecções por Clostridium/veterinária , Enterite/tratamento farmacológico , Necrose/tratamento farmacológico , Óleos Voláteis/química , Extratos Vegetais/química , Doenças das Aves Domésticas/tratamento farmacológico , Taninos/química , Animais , Antibacterianos/uso terapêutico , Anti-Infecciosos/química , Infecções por Clostridium/tratamento farmacológico , Clostridium perfringens/efeitos dos fármacos , Farmacorresistência Bacteriana , Tolerância a Medicamentos , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Aves Domésticas
9.
Anaerobe ; 34: 139-45, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26037239

RESUMO

Tannins added in the diet are being used to improve nutrition and health in farm animals as an alternative to antibiotic growth promoters and to control enteric clostridial diseases. However, the capacity of Clostridium perfringens to develop resistance under the selective pressure of tannins is unknown. The purpose of this study was to determine if C. perfringens possess the ability to develop resistance against tannins in comparison with antimicrobial agents. Susceptibility for 7 AGPs (antimicrobial growth promoters), 9 therapeutic antimicrobials and 2 tannin based extracts was determined for 30 C. perfringens strains isolated from poultry and cattle. Two susceptible strains were selected and cultured in presence of sub-inhibitory concentrations of tannins and AGPs for resistant sub-populations selection. Tannin resistance of C. perfringens isolates from both animal species revealed no statistically significant differences in MICs (minimum inhibitory concentration). Poultry isolates showed higher MICs to several AGPs compared with cattle isolates. All isolates were susceptible to the therapeutic antimicrobials tested, but avian isolates showed a significantly lower susceptibility to these antimicrobials which was highly correlated with an increased resistance to bacitracin and others AGPs. In-vitro selection of resistant clones suggests that C. perfringens was unable to develop resistance against tannins at least compared to AGPs like bacitracin and avilamycin. Avian origin strains, which were previously exposed to antibiotics showed higher resistance, compared to cattle origin strains. These results suggest that the evolution of resistance against tannins in C. perfringens would be more difficult and slower than to the determined AGPs.


Assuntos
Anti-Infecciosos/metabolismo , Clostridium perfringens/efeitos dos fármacos , Tolerância a Medicamentos , Proantocianidinas/metabolismo , Animais , Bovinos , Clostridium perfringens/isolamento & purificação , Hidrólise , Testes de Sensibilidade Microbiana , Mutação , Taxa de Mutação , Aves Domésticas , Seleção Genética , Inoculações Seriadas
10.
Int J Obstet Anesth ; 24(3): 276-80, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936783

RESUMO

Parturients with super-morbid obesity, defined as body mass index greater than 50kg/m(2), represent a growing segment of patients who require anesthetic care for labor and delivery. Severe obesity and its comorbid conditions place the parturient and fetus at greater risk for pregnancy complications and cesarean delivery, as well as surgical and anesthetic complications. The surgical approach for cesarean delivery in these patients may require a supra-umbilical vertical midline incision due to a large pannus. The dense T4-level of spinal anesthesia can cause difficulties with ventilation for the obese patient during the procedure, which can be prolonged. Patients also may have respiratory complications in the postoperative period due to pain from the incision. We describe the anesthetic management of three parturients with body mass index ranging from 73 to 95kg/m(2) who had a cesarean delivery via a supra-umbilical vertical midline incision. Continuous lumbar spinal and low thoracic epidural catheters were placed in each patient for intraoperative anesthesia and postoperative analgesia, respectively. Continuous spinal catheters were dosed with incremental bupivacaine boluses to achieve surgical anesthesia. In one case, the patient required respiratory support with non-invasive positive pressure ventilation. Two cases were complicated by intraoperative hemorrhage. All patients had satisfactory postoperative analgesia with a thoracic epidural infusion. None suffered postoperative respiratory complications or postdural puncture headache. The use of a continuous lumbar spinal catheter and a low thoracic epidural provides several advantages in the anesthetic management of super-morbidly obese parturients for cesarean delivery.


Assuntos
Anestesia Obstétrica/métodos , Raquianestesia/métodos , Cesárea , Obesidade Mórbida/complicações , Adulto , Anestesia Obstétrica/instrumentação , Raquianestesia/instrumentação , Catéteres , Feminino , Humanos , Gravidez
11.
Enferm Intensiva ; 21(1): 28-33, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20170833

RESUMO

INTRODUCTION: Continuous renal replacement therapy (CRRT) has experienced significant advances that have lead to an increase of its indications and improved the technology used in continued pressures monitoring. AIM: This study has aimed to discover if there are any associations between the increase of the circuit pressures and their duration. MATERIALS AND METHODS: A prospective, longitudinal analytic pilot study was conducted in an Intensive Care Unit of a university hospital from October 2008 to April 2009. The study analyzed the patient's information with CRRT and the hourly values of entry pressure (EP), comeback pressure (CP), transmembrane pressure (TMP) and pre-filter pressure (PFP). The Spearman correlation and the Student's T test were used. RESULTS: The study analyzed 44 sets corresponding to 11 patients (45.5% men and 54.5% women) with a life expectancy of 62 years. The same light catheter GamCath (11 French) and Continuous Venovenous Hemodiafiltration (CVVHDF) therapy were used in all patients. The mean duration of the circuits was 39 h. Mean, median, maximum and minimum values of the sample pressures were: EP:-52.17; -52.57; 160; -256 (millimeters of mercury) mmHg]; CP: (98.6; 95.3; 323; -2 mmHg); TMP: (58.57; 58.52; 245; -20 mmHg) and PFP: (161.76; 159.42; 375; -13 mmHg), respectively. CONCLUSIONS: A negative correlation was demonstrated between the duration of the sets and the mean CP and PFP. The sample obtained circuits withdrawn due to finished treatment (72 h), and by coagulation or changes in pressures.


Assuntos
Terapia de Substituição Renal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Estudos Prospectivos , Terapia de Substituição Renal/métodos , Terapia de Substituição Renal/normas
12.
J Dairy Sci ; 83(7): 1451-5, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10908052

RESUMO

Some dairy producers resist using bovine somatotropin (bST) beginning at 9 wk postpartum because of the concern that fertility is compromised. We conducted a trial with a total of 205 Holstein cows, 100 multiparous and 105 primiparous, to evaluate reproductive performance in two high producing herds in Arizona and southern California. Rolling herd averages for both herds for milk production exceeded 10,700 kg/yr. Data were collected for cows calving December 1996 through August 1997. The voluntary waiting period was 60 d postcalving, with cows randomly assigned to receive bST or no treatment (controls). In the 180-d interval after calving, 65.4% (68/104) of the control cows were diagnosed pregnant. With bST-treated cows, 48.5% (49/101) were pregnant in that same interval. A chi-square value from a linear model indicated that pregnancy outcome differed significantly between treatment groups. With a similar method of analysis, first-service conception rate was not significantly different between treatment groups. An extended voluntary wait and breeding interval is recommended for cows receiving bST, similar to suggestions from other published reports.


Assuntos
Hormônio do Crescimento/farmacologia , Reprodução/efeitos dos fármacos , Animais , Arizona , Cruzamento , California , Bovinos , Feminino , Lactação/efeitos dos fármacos , Paridade , Gravidez , Resultado da Gravidez , Fatores de Tempo
13.
J Cell Biol ; 127(5): 1289-99, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7962090

RESUMO

The reorganization from a radial [corrected] interphase microtubule (MT) network into a bipolar spindle at the onset of mitosis involves a dramatic change in MT dynamics. Microtubule-associated proteins (MAPs) and other factors are thought to regulate MT dynamics both in interphase and in mitosis. In this study we report the purification and functional in vitro characterization of a 230-KD MAP from Xenopus egg extract (XMAP230). This protein is present in eggs, oocytes, testis and a Xenopus tissue culture cell line. It is apparently absent from non-dividing cells in which an immunologically related 200-kD protein is found. XMAP230 is composed of two isoforms with slightly different molecular masses and pIs. It is localized to interphase MTs, dissociates from MTs at the onset of prophase and specifically binds to spindle MTs during metaphase and anaphase. The dissociation constant of XMAP230 is 500 nM, the stoichiometry of binding to MTs is between 1:8 and 1:4, and the in vivo concentration is approximately 200 nM. Both isoforms are phosphorylated and have reduced affinity for microtubules in mitotic extracts. Analysis of the effect of XMAP230 on MT dynamics by video microscopy shows that it increases the growth rate, decreases the shrinking rate of MTs and strongly suppresses catastrophes. These results suggest that in vivo, XMAP230 participates in the control of the MT elongation rate, stabilizes MTs and locally modulates MT dynamics during mitosis.


Assuntos
Divisão Celular , Proteínas Associadas aos Microtúbulos/fisiologia , Microtúbulos/metabolismo , Animais , Linhagem Celular , Feminino , Interfase , Ponto Isoelétrico , Masculino , Microscopia de Vídeo , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Proteínas Associadas aos Microtúbulos/farmacologia , Microtúbulos/efeitos dos fármacos , Microtúbulos/ultraestrutura , Mitose , Oócitos/metabolismo , Óvulo/metabolismo , Fosforilação , Fuso Acromático/metabolismo , Testículo/metabolismo , Tubulina (Proteína)/metabolismo , Xenopus laevis
14.
Gut ; 35(6): 822-7, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7517379

RESUMO

The role of the inflammatory response in acute pancreatitis and its relation with the clinical course was examined. This study examined if the serial measurement of polymorphonuclear granulocyte (PMN) elastase/A1PI complex, phospholipase A catalytic activity, C reactive protein, and other acute phase proteins, and the protease inhibitor alpha 2-macroglobulin, provides meaningful information for prognosis. Eighty non-consecutive patients with acute pancreatitis, classified according to their clinical outcome into mild (n = 40) and severe pancreatitis (n = 40), were followed up daily. Between 48 hours, median values of PMN-elastase, C reactive protein--and most of the acute phase proteins--and phospholipase A activity, were significantly higher in the severe pancreatitis group. PMN elastase shows a dynamic course and it reaches an early peak value at days 1-2, followed by C reactive protein (days 2-4) phospholipase A (day 3), and a negative peak for alpha 2-macroglobulin (days 4-5). PMN elastase (day 1) and C reactive protein (day 2) were selected by discriminant analysis as the most useful variables studied to allow the early accurate prediction of severity (sensitivity 100%, specificity 95%). Little or no predictive additional value was found for all other variables studied. These results strongly suggest a close relation between inflammatory parameters and clinical course in acute pancreatitis, and discriminant analysis of these variables provides a useful method to classify severity.


Assuntos
Biomarcadores/sangue , Elastase de Leucócito , Pancreatite/sangue , Doença Aguda , Proteínas de Fase Aguda/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Discriminante , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neutrófilos/enzimologia , Elastase Pancreática/análise , Fosfolipases A/sangue , Valor Preditivo dos Testes , Prognóstico , Fatores de Tempo , alfa 1-Antitripsina/análise
15.
J Cell Sci ; 107 ( Pt 2): 601-11, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8207082

RESUMO

The centrosome is the main microtubule organizing center of mammalian cells. Structurally, it is composed of a pair of centrioles surrounded by a fibro-granular material (the pericentriolar material) from which microtubules are nucleated. However, the nature of centrosomal molecules involved in microtubules nucleation is still obscure. Since brain microtubule-associated proteins (MAPs) lower the critical tubulin concentration required for microtubule nucleation in tubulin solution in vitro, we have examined their possible association with centrosomes. By immunofluorescence, monoclonal and polyclonal antibodies raised against MAP1B stain the centrosome in cultured cells as well as purified centrosomes, whereas antibodies raised against MAP2 give a completely negative reaction. The MAP1B-related antigen is localized to the pericentriolar material as revealed by immunoelectron microscopy. In preparations of purified centrosomes analyzed on poly-acrylamide gels, a protein that migrates as brain MAP1B is present. After blotting on nitrocellulose, it is decorated by anti-MAP1B antibodies and the amino acid sequence of proteolytic fragments of this protein is similar to brain MAP1B. Moreover, brain MAP1B and its centrosomal counterpart share the same phosphorylation features and have similar peptide maps. These data strongly suggest that a protein homologue to MAP1B is present in centrosomes and it is a good candidate for being involved in the nucleating activity of the pericentriolar material.


Assuntos
Antígenos de Bactérias , Proteínas da Membrana Bacteriana Externa/metabolismo , Encéfalo/metabolismo , Sequência de Aminoácidos , Animais , Antígenos/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Encéfalo/imunologia , Encéfalo/ultraestrutura , Linhagem Celular , Centríolos/metabolismo , Centríolos/ultraestrutura , Imunofluorescência , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Imunoeletrônica , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Dados de Sequência Molecular , Mapeamento de Peptídeos , Fosforilação
16.
Mol Cell Biochem ; 130(2): 187-96, 1994 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-8028597

RESUMO

COS-1 cells were transfected with cDNAs coding for different human tau isoforms. Expressed tau isoforms bind to cellular microtubules in vivo, preferentially at the distal regions of microtubules nucleated by the centrosome, leading to their stabilization. Eventually, tau-coated microtubules without any association with the centrosome were observed. A major difference between tau isoforms containing three tubulin-binding motifs and tau isoforms containing four tubulin-binding motifs is the greater ability of the latter in inducing the formation of long cytoplasmic processes.


Assuntos
Centríolos/fisiologia , Citoplasma/metabolismo , Microtúbulos/metabolismo , Proteínas tau/biossíntese , Sequência de Bases , Linhagem Celular , Citoplasma/ultraestrutura , Humanos , Dados de Sequência Molecular , Transfecção
17.
Mol Cell Biochem ; 121(1): 67-74, 1993 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-8510674

RESUMO

The mechanisms involved in cellular activation and damage by bacterial endotoxins are not completely defined. In particular, there is little information about possible intracellular targets of endotoxins. Recently, the participation of a microtubule associated protein in endotoxin actions on macrophages has been suggested. In the present work, we have studied the effect of E. coli lipopolysaccharide on the polymerization of microtubular protein in vitro. Electrophoretic analysis of the polymerization mixtures showed that the endotoxin inhibited the polymerization when present at high concentrations. At lower concentrations, LPS selectively displaced the microtubule associated protein MAP-2 from the polymerized microtubules. Electron microscopy showed that LPS binds to microtubules of tubulin + MAPs and to microtubules of purified tubulin (without MAPs) polymerized with taxol. Gel filtration experiments confirmed the binding of LPS to tubulin, and by ligand blot assays an interaction LPS-MAP-2 was detected. The ability of LPS to interact with microtubular proteins suggests a possible participation of microtubules on the cellular effects of endotoxins.


Assuntos
Lipopolissacarídeos/metabolismo , Microtúbulos/metabolismo , Animais , Bovinos , Técnicas In Vitro , Lipopolissacarídeos/farmacologia , Proteínas Associadas aos Microtúbulos/efeitos dos fármacos , Microtúbulos/efeitos dos fármacos , Tubulina (Proteína)/efeitos dos fármacos
18.
Gut ; 33(9): 1264-7, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1427382

RESUMO

Plasma values of immunoreactive interleukin-6, C-reactive protein and phospholipase A have been determined in serial samples from 24 patients with acute pancreatitis ('mild' pancreatitis nine, 'severe' pancreatitis 15). Median plasma concentrations of interleukin-6, C-reactive protein, and phospholipase A activity were significantly higher in patients with 'severe' illness (p < 0.001) than those with 'mild' illness. A particularly marked increase in interleukin-6 was found in two patients with necrotising pancreatitis and fatal outcome. Significant correlations between plasma concentrations of interleukin-6 and phospholipase A (p = 0.0218) and C-reactive protein and phospholipase A activity (p < 0.0001) were found in patients with 'severe' disease. These findings in a limited number of patients with acute pancreatitis are promising in that raised interleukin-6 correlated with clinical severity and with two other established markers, C-reactive protein, and phospholipase A activity.


Assuntos
Proteína C-Reativa/análise , Interleucina-6/sangue , Pancreatite/sangue , Fosfolipases A/sangue , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
19.
J Cell Sci Suppl ; 15: 51-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1824107

RESUMO

The development of highly asymmetrical neurones from undifferentiated neuroblasts involves the extension of processes (axon and dendrites), that depends on the assembly of an inner microtubule scaffolding. Clonal cell lines of neuronal origin, N2A and NIE-115 neuroblastoma cells, have been chosen as model systems to study the modifications of microtubule protein which accompany the outgrowth of axon-like processes (neurites). Neuroblastoma cells grow as proliferating and undifferentiated cells in standard culture medium but can be considered as committed neuronal precursors. Thus, they are characterized by a high content of tubulin, including the minor neuronal-specific beta 3 isoform, and of MAPs including MAP1B and tau-like proteins. Serum withdrawal from the culture medium results in the extension of axon-like processes which is paralleled by a net increase in the amount of assembled tubulin. However, there is not any increase in the total amount of either tubulin or major MAPs which suggests an involvement of other regulatory factors in the promotion of microtubule assembly. Of relevance in this respect is the fact that beta 3-tubulin, MAP1B, and tau-like proteins become phosphorylated during neurite extension. A casein kinase II-like enzyme may be involved in some of these phosphorylation events. This enzyme is primarily localized to the nuclei in undifferentiated neuroblastoma cells, whereas a wider distribution of the enzyme between the nucleus and the cytoplasm is found in differentiating neuroblastoma cells. It thus appears plausible that a modified sorting of casein kinase II into the nucleus and the cytoplasm may be involved in the triggering of the phosphorylation of microtubule proteins during neuroblastoma cell differentiation.


Assuntos
Proteínas Associadas aos Microtúbulos/metabolismo , Neuritos/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Bovinos , Diferenciação Celular , Imunofluorescência , Neuritos/fisiologia , Neuroblastoma/metabolismo , Fosforilação , Transdução de Sinais , Células Tumorais Cultivadas
20.
Int J Biochem ; 22(12): 1419-25, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2276416

RESUMO

1. Tubulin, lacking the carboxy terminus region of its beta subunit assembles into composite microtubule structures showing opposite polarity. 2. Since in these polymers, microtubules are laterally bound, this type of interaction could lead to the generation of microtubules with different polarities, as those found in some cellular types.


Assuntos
Microtúbulos/ultraestrutura , Tubulina (Proteína)/metabolismo , Animais , Bovinos , Endopeptidases/metabolismo , Hidrólise , Microscopia Eletrônica , Óptica e Fotônica , Staphylococcus aureus/enzimologia , Tubulina (Proteína)/ultraestrutura
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