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1.
Int J Immunopathol Pharmacol ; 27(3): 371-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25280028

RESUMO

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS) is a well-defined syndrome in which tics (motor and/or vocal) and/or obsessive compulsive disorders (OCD) consistently exacerbate in temporal correlation to a Group A beta-haemolytic streptococcal infection. In children with PANDAS, there is speculation about whether tonsillectomy or adenotonsillectomy might improve the neuropsychiatric course. Our objective was to examine whether such surgery impacted remission or, in patients without remission, modified clinical course of the disease, streptococcal antibody titers, neuronal antibodies or clinical severity of Obsessive-Compulsive Disorder (OCD) and/or tics. Study participants (n = 120) with positive PANDAS criteria were recruited, examined, and divided into surgical or non-surgery groups. The surgical group consisted of children with tonsillectomy or adenotonsillectomy (n=56). The remaining children were categorized as non-surgery (n=64). Clinical follow-up was made every 2 months for more than 2 years. Surgery did not affect symptomatology progression, streptococcal and neuronal antibodies, or the clinical severity of neuropsychiatric symptoms in these children. In conclusion, in our series clinical progression, antibody production, and neuropsychiatric symptom severity did not differ on the basis of surgical status. We cannot uphold surgical management as likely to impact positive remission rates, course of OCD/tics, or antibody concentrations in children with PANDAS.


Assuntos
Doenças Autoimunes/etiologia , Transtorno Obsessivo-Compulsivo/etiologia , Infecções Estreptocócicas/complicações , Streptococcus pyogenes , Tiques/etiologia , Tonsilectomia , Adenoidectomia , Criança , Feminino , Humanos , Masculino
2.
J Comp Neurol ; 518(7): 1046-63, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20127807

RESUMO

The effects of deafness on brain structure and function have been studied using animal models of congenital deafness that include surgical ablation of the organ of Corti, acoustic trauma, ototoxic drugs, and hereditary deafness. This report describes the morphologic plasticity of auditory nerve synapses in response to ototoxic deafening and chronic electrical stimulation of the auditory nerve. Normal kittens were deafened by neonatal administration of neomycin that eliminated auditory receptor cells. Some of these cats were raised deaf, whereas others were chronically implanted with cochlear electrodes at 2 months of age and electrically stimulated for up to 12 months. The large endings of the auditory nerve, endbulbs of Held, were studied because they hold a key position in the timing pathway for sound localization, are readily identifiable, and exhibit deafness-associated abnormalities. Compared with those of normal hearing cats, synapses of ototoxically deafened cats displayed expanded postsynaptic densities, a 35.4% decrease in synaptic vesicle (SV) density, and a reduction in the somatic size of spherical bushy cells (SBCs). In comparison with normal hearing cats, ototoxically deafened cats that received cochlear stimulation had endbulbs that expressed postsynaptic densities (PSDs) that were statistically identical in size, showed a 48.1% reduction in SV density, and whose target SBCs had a 25.5% reduction in soma area. These results demonstrate that electrical stimulation via a cochlear implant in chemically deafened cats preserves PSD size but not other aspects of synapse morphology. This determination further suggests that the effects of ototoxic deafness are not identical to those of hereditary deafness.


Assuntos
Nervo Coclear/fisiopatologia , Núcleo Coclear/ultraestrutura , Surdez/fisiopatologia , Plasticidade Neuronal , Sinapses/ultraestrutura , Animais , Antibacterianos/toxicidade , Gatos , Nervo Coclear/ultraestrutura , Núcleo Coclear/fisiopatologia , Surdez/induzido quimicamente , Modelos Animais de Doenças , Estimulação Elétrica/métodos , Eletrodos Implantados , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Feminino , Masculino , Microscopia Eletrônica , Neomicina/toxicidade , Terminações Nervosas/ultraestrutura
4.
Cell Transplant ; 15(5): 369-80, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16970279

RESUMO

Spiral ganglion neurons (SGNs), the primary afferent neurons of the cochlea, degenerate following a sensorineural hearing loss (SNHL) due to lack of trophic support normally received from hair cells. Cell transplantation is emerging as a potential strategy for inner ear rehabilitation, as injected cells may be able to replace damaged SGNs in the deafened cochlea. An increase in the number of surviving SGNs may result in improved efficacy of cochlear implants (CIs). We examined the survival of partially differentiated mouse embryonic stem cells (MESCs), following xenograft transplantation into the deafened guinea pig cochlea (n=15). Cells were delivered directly into the left scala tympani via microinjection through the round window. Small numbers of MESCs were detected in the scala tympani for up to 4 weeks following transplantation and a proportion of these cells retained expression of neurofilament protein 68 kDa in vivo. While this delivery method requires refinement for effective long-term replacement of damaged SGNs, small numbers of MESCs were capable of survival in the deafened mammalian cochlea for up to 4 weeks, without causing an inflammatory tissue response.


Assuntos
Cóclea/cirurgia , Perda Auditiva Neurossensorial/cirurgia , Transplante de Células-Tronco/métodos , Células-Tronco/citologia , Animais , Vias Auditivas/citologia , Vias Auditivas/fisiologia , Cóclea/patologia , Sobrevivência de Enxerto/fisiologia , Proteínas de Fluorescência Verde/análise , Cobaias , Imuno-Histoquímica/métodos , Camundongos , Modelos Teóricos , Proteínas de Neurofilamentos/análise , Células-Tronco/metabolismo , Células-Tronco/fisiologia , Transplante Heterólogo
5.
Neurology ; 67(5): 761-5, 2006 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-16899545

RESUMO

OBJECTIVE: To identify factors associated with tolerance and survival after noninvasive positive-pressure ventilation (NIPPV) and to investigate the influence of NIPPV on lung function in patients with ALS. METHODS: NIPPV was offered to 71 patients with ALS in accordance with currently published guidelines. Effects of NIPPV on lung function and factors influencing tolerance and survival after NIPPV were studied. RESULTS: Forty-four patients (61.9%; 95% CI: 50.6 to 73.2) tolerated NIPPV (NIPPV use >or=4 h/day) and 27 (38.1%; 95% CI: 26.8 to 49.4) were intolerant (NIPPV use <4 h/day). Patients with mild or moderate bulbar symptoms were more likely to tolerate NIPPV than those with severe impairment (odds ratio = 6.09, 95% CI: 1.18 to 31.52, p = 0.031). After NIPPV introduction, a slower decline in forced vital capacity (FVC) was observed in tolerant vs intolerant patients (p = 0.002). The slope of FVC decline after NIPPV initiation (risk ratio [RR]: 0.78, 95% CI: 0.65 to 0.94, p = 0.01) together with NIPPV tolerance (RR: 0.32, 95% CI: 0.13 to 0.78, p = 0.013) were the only independent predictors of survival in the overall group of patients. In multivariate analysis, body mass index was the most powerful predictor of longer survival after NIPPV in tolerant patients (RR: 0.77, 95% CI: 0.61 to 0.96, p = 0.022). CONCLUSION: Survival after noninvasive ventilation was independently related to ventilatory use (>or=4 h/day) and to the modifications of forced vital capacity decline after treatment initiation. The severity of bulbar impairment and the nutritional status of the ALS patients at the introduction of ventilation may predict tolerance and survival.


Assuntos
Esclerose Lateral Amiotrófica/terapia , Respiração com Pressão Positiva/mortalidade , Respiração com Pressão Positiva/métodos , Ventiladores Mecânicos , Idoso , Esclerose Lateral Amiotrófica/fisiopatologia , Demografia , Feminino , Seguimentos , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Testes de Função Respiratória/métodos , Estudos Retrospectivos , Perfil de Impacto da Doença , Taxa de Sobrevida , Fatores de Tempo
7.
Physiol Genomics ; 19(2): 170-4, 2004 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-15252189

RESUMO

Adiponectin is a circulating enhancer of insulin action that is secreted by the adipose tissue. In epidemiological studies, serum levels of this protein predict the risk of type 2 diabetes and cardiovascular events. Serum adiponectin levels have been associated with variants at the adiponectin (APM1) and PPARgamma2 loci and have also been linked to markers on 5p15 and 14q13. We investigated the role of these four loci in regulating serum adiponectin in a Caucasian population from Italy. Four haplotype-tagging single-nucleotide polymorphisms (ht-SNPs) (-11377 C>G, -4041 A>C, +45 T>G, and +276 G>T) at the APM1 locus and the PPARgamma2 Pro12Ala polymorphism were examined for association with serum adiponectin in 413 unrelated, nondiabetic individuals. Of the five SNPs tested, +276G>T was the only one to be associated with serum adiponectin (P = 0.032), with "TT" individuals having higher adiponectin levels than other subjects. In a variance-components analysis of 737 nondiabetic members of 264 nuclear families, adiponectin heritability was 30%, with a small but significant proportion explained by the +276 genotype ( P = 0.0034). Suggestive evidence of linkage with adiponectin levels was observed on chromosome 14q13, with a LOD of 2.92 (P = 0.000057) after including the APM1 +276 genotype in the model. No linkage was observed at 5p15. Our data indicate a strong genetic control of serum adiponectin. A small proportion of this can be attributed in our population to variability at the APM1 locus, but an as yet unidentified gene on 14q13 appears to play a much bigger role.


Assuntos
Cromossomos Humanos Par 14/genética , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Peptídeos e Proteínas de Sinalização Intercelular/genética , Família Multigênica/genética , Adiponectina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/genética , Jejum , Feminino , Ligação Genética/genética , Genótipo , Haplótipos/genética , Humanos , Itália , Masculino , Pessoa de Meia-Idade
8.
J Mol Med (Berl) ; 81(11): 718-23, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14574455

RESUMO

Insulin resistance is believed to be under the control of several genes often interacting each other. However, whether genetic epistasis does in fact modulate human insulin sensitivity is unknown. In 338 healthy unrelated subjects from Sicily, all nondiabetic and not morbidly obese, we investigated whether two gene polymorphisms previously associated with insulin resistance (namely PC-1 K121Q and PPARgamma2 P12A) affect insulin sensitivity by interacting. PC-1 X121Q subjects showed higher level of fasting glucose, lower insulin sensitivity (by both the Matsuda insulin sensitivity index and M values at clamp, the latter performed in a subgroup of 113 subjects representative of the overall cohort) and higher insulin levels during the oral glucose tolerance test (OGTT) than PC-1 K121K subjects. In contrast, no difference in any of the measured variables was observed between PPARgamma2 P12P and X12A individuals. The deleterious effect of the PC-1 X121Q genotype on each of these three variables was significant and entirely dependent upon the coexistence of the PPARgamma2 P12P genotype. Among PPARgamma2 P12P carriers also fasting insulin and glucose levels during OGTT were higher in PC-1 X121Q than in K121K individuals. In contrast, no deleterious effect of the PC-1 X121Q genotype was observed among PPARgamma2 X12A carriers; rather, in these subjects a lower body mass index and consequently lower fasting insulin level was observed in PC-1 X121Q than in K121K carriers. Overall, a significant interaction between the two genes was observed on body mass index, insulin levels (both fasting and after OGTT) and both insulin sensitivity (i.e., insulin sensitivity index and M value) and insulin secretion (i.e., HOMA-B%) indexes.


Assuntos
Resistência à Insulina/genética , PPAR gama/genética , Diester Fosfórico Hidrolases/genética , Polimorfismo Genético/genética , Pirofosfatases/genética , Adulto , Glicemia/metabolismo , Feminino , Humanos , Masculino , Obesidade Mórbida/genética , Polimorfismo de Nucleotídeo Único/genética , Valores de Referência
9.
Thyroid ; 13(4): 341-3, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12804102

RESUMO

Ten years after the first description of activating mutations in the thyroid stimulating hormone receptor (TSHR) gene in sporadic autonomous hyperfunctioning thyroid adenomas, there is general agreement in assigning a major pathogenic role of this genetic abnormality, acting via the constitutive activation of the cAMP pathway, in both the growth and functional characteristic of these tumours. From the beginning, however, the pathophysiological and clinical relevance of somatic TSHR mutations has been debated and some arguments still exist against a fully causative role of these mutations and the practical value of detecting these mutations for the diagnosis, treatment and prognosis of thyroid hot nodules. Some major issues will be examined herein, including (a) the frequency of TSHR alterations in various reports showing that the genetic abnormality underlying the pathogenesis of a substantial subset of thyroid tumours has yet to be identified; (b) the limitations of the present experimental models, which suggest greater caution in the interpretation of in vitro results; (c) the still unresolved question of absence of genotype-phenotype correlation. Clarification of these issues may hopefully provide new and useful tools for improving the clinical management of this disease.


Assuntos
Adenoma/genética , Adenoma/fisiopatologia , Mutação , Receptores da Tireotropina/genética , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/fisiopatologia , Humanos , Nódulo da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/fisiopatologia
10.
Radiol Med ; 104(3): 203-12, 2002 Sep.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-12471368

RESUMO

The security of electronic medical information is very important for health care organisations, which have to ensure confidentiality, integrity and availability of the information provided. This paper will briefly outline the legal measures adopted by the European Community, Italy and the United States to regulate the use and disclosure of medical records. It will then go on to highlight how information technology can help to address these issues with special reference to the management of organisation policies. To this end, we will present a modelling example for the security policy of a radiological department.


Assuntos
Segurança Computacional , Sistemas Computadorizados de Registros Médicos , Sistemas de Informação em Radiologia , Confidencialidade , Europa (Continente) , Humanos , Internet , Itália , Estados Unidos
11.
Am J Respir Crit Care Med ; 164(2): 225-30, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11463592

RESUMO

We designed a prospective multicenter randomized controlled study in three long-term weaning units (LWU) to evaluate which protocol, inspiratory pressure support ventilation (PSV) or spontaneous breathing trials (SB), is more effective in weaning patients with chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation for more than 15 d. Fifty-two of 75 patients, failing an initial T-piece trial at admission, were randomly assigned to PSV or SB (26 in both groups). No significant difference was found in weaning success rate (73% versus 77% in the PSV and SB group, respectively), mortality rate (11.5% versus 7.6%), duration of ventilatory assistance (181 +/- 161 versus 130 +/- 106 h), LWU (33 +/- 12 versus 35 +/- 19 d), or total hospital stay. The results of these defined protocols were retrospectively compared with an "uncontrolled clinical practice" in weaning historical control patients. The overall 30-d weaning success rate was significantly greater (87% versus 70%) and the time spent under mechanical ventilation by survived and weaned patients was shorter in the patients in the study than in historical control patients (103 +/- 144 versus 170 +/- 127 h). The LWU and hospital stays were also significantly shorter (27 +/- 12 versus 38 +/- 18 and 38 +/- 17 versus 47 +/- 18 d). Spontaneous breathing trials and decreasing levels of PSV are equally effective in difficult-to-wean patients with COPD. The application of a well-defined protocol, independent of the mode used, may result in better outcomes than uncontrolled clinical practice.


Assuntos
Pneumopatias Obstrutivas/terapia , Desmame do Respirador/métodos , Idoso , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Tempo
12.
Fam Med ; 32(9): 639-44, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11039152

RESUMO

BACKGROUND AND OBJECTIVES: In the context of a dramatic increase in US cesarean delivery rates over the past 30 years and explicit national goals to decrease the cesarean rate, previous retrospective studies have shown that pregnant women cared for by family physicians may be less likely to undergo cesarean delivery, compared with patients cared for by obstetricians. METHODS: We conducted a retrospective chart review of 3,560 deliveries from the family practice service of a community-based family practice residency from 1986-1995, focusing primarily on cesarean delivery rates during two periods of time. During period 1 (n = 1,063), all attending were private practice obstetricians. After a transition period, all births were attended by family medicine faculty (period 2, n = 1,346). RESULTS: The total cesarean delivery rate declined from 16.7% in period 1 to 11.1% in period 2. Repeat cesareans declined from 8.5% to 2.9%. CONCLUSIONS: In this community-based residency, a change in the specialty of the attending physician was associated with a 34% decline in the cesarean delivery rate. The observed decline in the cesarean rate could not be accounted for by any change in patient demographics or secular trends in cesarean delivery rates.


Assuntos
Cesárea/estatística & dados numéricos , Medicina de Família e Comunidade , Obstetrícia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Nascimento Vaginal Após Cesárea/estatística & dados numéricos
13.
Postgrad Med ; 107(4): 63-6, 69-74, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10778411

RESUMO

Infectious vaginitis is a common clinical problem. Unfortunately, treatment, including self-medication, is often instituted before an adequate evaluation has been performed. An accurate diagnosis can usually be made in the office setting, and effective pharmacologic treatments are readily available.


Assuntos
Vaginite/diagnóstico , Candidíase Vulvovaginal/diagnóstico , Candidíase Vulvovaginal/tratamento farmacológico , Feminino , Humanos , Vaginite por Trichomonas/diagnóstico , Vaginite por Trichomonas/tratamento farmacológico , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/tratamento farmacológico
14.
Am Fam Physician ; 60(2): 489-96, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10465224

RESUMO

Primary dysmenorrhea is defined as cramping pain in the lower abdomen occurring just before or during menstruation, in the absence of other diseases such as endometriosis. Prevalence rates are as high as 90 percent. Initial presentation of primary dysmenorrhea typically occurs in adolescence. It is a common cause of absenteeism and reduced quality of life in women. The problem is often underdiagnosed and undertreated. Women with primary dysmenorrhea have increased production of endometrial prostaglandin, resulting in increased uterine tone and stronger, more frequent uterine contractions. A diagnostic evaluation is unnecessary in patients with typical symptoms and no risk factors for secondary causes. Nonsteroidal anti-inflammatory medications are the mainstay of treatment, with the addition of oral contraceptive pills when necessary. About 10 percent of affected women do not respond to these measures. It is important to consider secondary causes of dysmenorrhea in women who do not respond to initial treatment. Many alternative treatments (ranging from acupuncture to laparoscopic surgery) have been studied, but the supporting studies are small, with limited long-term follow-up.


Assuntos
Dismenorreia , Algoritmos , Dismenorreia/diagnóstico , Dismenorreia/epidemiologia , Dismenorreia/etiologia , Dismenorreia/terapia , Feminino , Humanos
15.
Am Fam Physician ; 58(3): 731-8, 742-4, 1998 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9750541

RESUMO

External cephalic version is a procedure that externally rotates the fetus from a breech presentation to a vertex presentation. External version has made a resurgence in the past 15 years because of a strong safety record and a success rate of about 65 percent. Before the resurgence of the use of external version, the only choices for breech delivery were cesarean section or a trial of labor. It is preferable to wait until term (37 weeks of gestation) before external version is attempted because of an increased success rate and avoidance of preterm delivery if complications arise. After the fetal head is gently disengaged, the fetus is manipulated by a forward roll or back flip. If unsuccessful, the version can be reattempted at a later time. The procedure should only be performed in a facility equipped for emergency cesarean section. The use of external cephalic version can produce considerable cost savings in the management of the breech fetus at term. It is a skill easily acquired by family physicians and should be a routine part of obstetric practice.


Assuntos
Versão Fetal/métodos , Algoritmos , Apresentação Pélvica , Tomada de Decisões , Feminino , Humanos , Educação de Pacientes como Assunto , Seleção de Pacientes , Gravidez , Materiais de Ensino , Versão Fetal/normas
16.
Dev Psychol ; 34(4): 723-30, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9681264

RESUMO

A group of Italian children (790 boys and 717 girls), 10-13 years old, were administered the Revised Class Play (Masten, Morison, & Pellegrini, 1985) in order to explore cross-cultural differences in social reputation with respect to North American studies. Children also were given sociometric nominations to examine the association between social reputation and peer acceptance-rejection. Exploratory and confirmatory factor analyses showed a 4-factor structure with the original Leadership-Sociability factor split in 2 separate dimensions: leadership and sociability. Leadership items seemed to draw a profile of a well-behaved, polite and socially correct child, whereas Sociability items seemed to draw a profile of a child that is sociable, liked, exuberant, and ready to make friends and to interact with others. Moreover, the data suggested somewhat subtle forms of association between Aggression and Sociability. Results on relations between peer acceptance-rejection and social reputation confirmed North American findings.


Assuntos
Características Culturais , Ajustamento Social , Adolescente , Agressão , Criança , Feminino , Humanos , Itália , Liderança , Masculino , Determinação da Personalidade
17.
Monaldi Arch Chest Dis ; 52(5): 444-6, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9510663

RESUMO

We report the successful outcome of first-line intervention of noninvasive positive pressure ventilation (NPPV) in four patients, three of whom had hypercapnic acute respiratory failure (ARF) and one hypoxaemic ARF, secondary to pulmonary oedema. The clinical condition showed rapid improvement and the NPPV, performed together with aggressive medical treatment, was effective in decreasing the respiratory frequency, and in correcting gas exchange abnormalities within the first 3 h. The average duration of nasal mask ventilation was 11 h (range 6-15 h). The patients were weaned, following ARF, by removing the ventilator whenever inspiratory positive airway pressure (IPAP) was 5 cmH2O. NPPV was applied, by nasal mask, using a bi-level positive airway pressure (BiPAP) delivering pressure support ventilation (PSV). We conclude that application of noninvasive positive pressure ventilation may be effective in correcting gas exchange abnormalities, in relieving respiratory distress and, perhaps, in avoiding endotracheal intubation in selected patients with acute respiratory failure secondary to reversible medical condition such as pulmonary oedema.


Assuntos
Respiração com Pressão Positiva/métodos , Edema Pulmonar/complicações , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia , Idoso , Humanos , Hipercapnia/etiologia , Hipóxia/etiologia , Masculino , Máscaras , Pessoa de Meia-Idade , Edema Pulmonar/terapia , Fatores de Tempo
18.
J Cell Biochem ; 33(4): 225-35, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3034931

RESUMO

The tyrosyl kinase and phosphatidylinositol (PI) kinase activities of human red cells have been partially purified and characterized. Although the PI kinase required detergent for solubilization, the major tyrosyl kinase of the red cell could be extracted by high salt. A very small residual activity remained associated with the membranes, however, that was solubilized with the PI kinase and copurified through an ammonium sulfate precipitation and diethylaminoethyl (DEAE) ion-exchange step gradient elution. However, the two activities were found to differ with respect to their apparent KmS for ATP and Mg2+; they showed different half-lives for temperature inactivation, possessed different relative activities in the presence of Mn2+ and Ca2+, and were separable by elution from a DEAE-Trisacryl ion exchange column using a linear NaCl gradient. The kinetic parameters of the membrane-associated tyrosyl kinase differed from those of the salt-extracted enzyme. PI kinase was not activated by pretreatment with the tyrosyl kinase p68v-ros or by addition of the phosphotyrosyl phosphatase inhibitor, vanadate, to intact membranes, and was not competitively inhibited by the tyrosyl kinase substrate poly(Glu4, Tyr). We conclude that the human red cell phosphatidylinositol and tyrosyl kinases are distinct and separate activities, and that at least two separable tyrosyl kinases are present in human erythrocytes.


Assuntos
Membrana Eritrocítica/enzimologia , Fosfotransferases/sangue , Proteínas Tirosina Quinases/sangue , 1-Fosfatidilinositol 4-Quinase , Cromatografia por Troca Iônica , Humanos , Cinética , Fosfoproteínas/sangue , Fosforilação , Relação Estrutura-Atividade
19.
Am J Physiol ; 251(6 Pt 1): C883-6, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3789131

RESUMO

The interaction of the dissociated catalytic subunit of adenosine 3',5'-cyclic monophosphate-dependent protein kinase (kinase A) and phosphatidylinositol metabolism has been studied in rat spleen lymphocyte membranes. As reported previously (Sarkadi et al., FEBS Lett. 152: 195-198, 1983) addition of kinase A increased by about twofold the phosphorylation of phosphatidylinositol in lymphocyte membranes at low ATP concentrations. However, we have found that this increase is an artifact of the assay conditions, and that the increase is a consequence of an inhibition of membrane adenosine triphosphatase activity by the protein kinase A. When lipid phosphorylation was measured under initial rate conditions, at high ATP concentrations, the increase was abolished. No effect of kinase A was observed on initial rates of the synthesis or hydrolysis of phosphatidylinositol phosphate. No phosphatidylinositol bisphosphate was produced in the membranes under any of the assay conditions used.


Assuntos
Linfócitos/metabolismo , Lipídeos de Membrana/metabolismo , Fosfatidilinositóis/metabolismo , Proteínas Quinases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Membrana Celular/metabolismo , Cinética , Substâncias Macromoleculares , Radioisótopos de Fósforo , Fosforilação , Ratos , Baço/metabolismo
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