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1.
Vox Sang ; 113(1): 51-59, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29023857

RESUMO

BACKGROUND AND OBJECTIVES: Whether transfusion-associated circulatory overload arises as a simple result of over-transfusion or requires another trigger remains unclear. Here, we examined whether respiratory distress could be reproduced by massive transfusion alone in an animal model. MATERIALS AND METHODS: A total of 20 anaesthetized swine were equipped with monitors. Allogeneic blood was obtained from 10 donor swine. A 4-stage loading protocol with each stage equivalent to 25% of the blood volume (BV) in the recipient swine was then used to infuse crystalloid (CR), hydroxyethyl starch (HES) or allogeneic blood (TR) (n = 5 each). The five remaining animals were subjected to a haemorrhagic shock (HS) prior to an allogeneic blood transfusion (TRS). RESULTS: The PaO2 /FiO2 (P/F) ratio did not decrease to the level of respiratory distress in either the CR group or the HES group after loading with a volume corresponding to 100% of the recipient BV. However, the TRS and TR groups exhibited significant reductions in the P/F ratio after fluid overloading (227 ± 29 and 267 ± 133, respectively). Blood transfusion after HS expanded the blood volume, but over-transfusion alone did not. HS was accompanied by an increase in the white blood cell count. CONCLUSION: The lung and the heart can tolerate volume overloads with HES, CR and even transfused blood. However, a preceding HS may induce an inflammatory response, making the lung vulnerable to subsequent blood overloads. In this study, a preceding haemorrhagic shock mediated respiratory distress following massive transfusion in a swine model. (247 words).


Assuntos
Transfusão de Sangue , Dispneia/etiologia , Choque Hemorrágico/complicações , Reação Transfusional/etiologia , Animais , Volume Sanguíneo , Feminino , Pulmão/patologia , Pulmão/fisiopatologia , Fatores de Risco , Sus scrofa , Transplante Homólogo , Resultado do Tratamento
2.
Transfus Med ; 26(5): 365-372, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27350440

RESUMO

BACKGROUND AND OBJECTIVES: The effect of leukoreduction and storage periods on the accumulation of bioactive lysophospholipids and substances in human autologous blood (AB units) has not been fully investigated. MATERIALS AND METHODS: The accumulation of bioactive lysophospholipids such as sphingosine 1-phosphate (S1P) and lysophosphatidylserine (LysoPS) in AB units during the storage was investigated. The time-dependent changes and the effect of the filtration in pre-storage leuckoreduction (LR) and unmodified samples derived from 46 AB units were analysed. Additionally, the changes of lysophospholipids and platelet releasate, namely ß-thromboglobulin (ß-TG), induced by exposure of whole blood (WB) or platelet-rich plasma (PRP) to the filter material were analysed. RESULTS: LysoPS, but not S1P levels, time-dependently and significantly increased in both unmodified and LR samples. LysoPS significantly decreased in LR compared with unmodified samples, whereas S1P increased in LR compared with unmodified samples. In addition, exposure of WB and/or PRP to the filter material in vitro resulted in increased levels of S1P, LysoPS and ß-TG. CONCLUSIONS: LR effectively reduced the accumulation of LysoPS in AB units. On the other hand, it increased concentrations of S1P due to platelet activation by exposure to the filter material. These suggest that increases of S1P levels in LR and LysoPS in the unmodified samples were mainly caused by the leukocytes and/or platelets and that LR was effective in inhibiting the accumulation of LysoPS.


Assuntos
Preservação de Sangue , Transfusão de Sangue Autóloga , Procedimentos de Redução de Leucócitos , Lisofosfolipídeos/sangue , Esfingosina/análogos & derivados , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esfingosina/sangue
3.
Transfus Med ; 25(1): 42-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25752582

RESUMO

OBJECTIVE: To prevent neonatal alloimmune thrombocytopenia due to anti-group A antibody perinatal management was performed. BACKGROUND: We previously reported a case of severe intracranial haemorrhage associated with neonatal alloimmune thrombocytopenia due to anti-group A isoantibody. MATERIAL/METHODS: A 40-year-old Japanese woman, gravida 4 para 1, was pregnant with her second baby. The previous sibling developed severe thrombocytopenia and died 10 days after birth due to intracranial haemorrhage. He was diagnosed with neonatal alloimmune thrombocytopenia; the causative antibody was found to be the anti-group A antibody. Prednisone was started at 7 weeks' gestational age. Intravenous immunoglobulin 1 g kg(-1) week(-1) was started at 29 weeks' gestational age and continued to delivery. Serological studies and genotyping were performed. RESULTS: The second boy was delivered at 33 weeks' gestational age by caesarean section. He was discharged without intracranial haemorrhage or thrombocytopenia. The anti-group A antibody titre in the maternal serum was 2048-4096 (normal range: 4-64). The anti-group A antibody titre in the newborn's serum was 4. Cross-matching between the maternal serum and the paternal platelets was positive. CONCLUSION: Owing to the history of neonatal alloimmune thrombocytopenia causing intracranial haemorrhage and death of the previous sibling, strict follow-up of the subsequent pregnancy was conducted.


Assuntos
Sistema ABO de Grupos Sanguíneos/sangue , Transfusão Feto-Materna/terapia , Isoanticorpos/sangue , Assistência Perinatal/métodos , Trombocitopenia Neonatal Aloimune/terapia , Feminino , Transfusão Feto-Materna/sangue , Humanos , Recém-Nascido , Masculino , Gravidez , Trombocitopenia Neonatal Aloimune/sangue
4.
Tissue Antigens ; 80(4): 336-40, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22776008

RESUMO

Human neutrophil antigens (HNAs) play an important role in a variety of clinical conditions including immune-mediated neutropenia, non-hemolytic transfusion reactions, and transfusion-related acute lung injury. The aim of this study was to investigate the frequency distribution of HNAs-1 to -5 among the Japanese population. We analyzed samples from 570 healthy Japanese by molecular and serologic techniques to estimate the gene frequencies of HNAs-1 to -5. DNA samples were obtained and typed for the HNA-1 (n = 523), -3 (n = 570), -4 (n = 570), and -5 (n = 508), by molecular techniques. The HNA-1 genotype was determined by using a commercial polymerase chain reaction-reverse sequence-specific oligonucleotide probes (PCR-rSSOP) kit. The HNA-3 to -5 genotypes were determined by the PCR-sequence specific primer (PCR-SSP), previously described, with a small modification. The HNA-2a phenotype was determined in 301 donors by granulocyte immunofluorescence test. In Japanese, the gene frequencies of HNA-1a, -1b, and -1c were 0.623, 0.377, and 0.000, respectively. The frequency of HNA-2a phenotype was 0.987, and the gene frequencies of HNA-3a and -3b were 0.654 and 0.346, respectively. HNA-4a and -4b were found at 1.000 and 0.000, respectively, and HNA-5a and -5b at 0.840 and 0.160, respectively. We describe, for the first time, the frequencies of all HNAs (HNA-1 to -5) among the Japanese population. This study will be helpful for the prediction of the risk of alloimmunization to HNA, especially to determine the risk of HNA alloantibody production by transfusion of HNA incompatible blood and feto-maternal incompatibility.


Assuntos
Povo Asiático/genética , Frequência do Gene , Isoantígenos/genética , Neutrófilos/metabolismo , Alelos , Primers do DNA , Feminino , Genótipo , Humanos , Isoantígenos/classificação , Isoantígenos/imunologia , Masculino , Tipagem Molecular , Neutrófilos/citologia , Neutrófilos/imunologia , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
5.
AJNR Am J Neuroradiol ; 41(12): 2243-2249, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33154076

RESUMO

BACKGROUND AND PURPOSE: Collateral vessels in Moyamoya disease represent potential sources of bleeding. To test whether these cortical distributions vary among subtypes, we investigated cortical terminations using both standardized MR imaging and MRA. MATERIALS AND METHODS: Patients with Moyamoya disease who underwent MR imaging with MRA in our institution were enrolled in this study. MRA was spatially normalized to the Montreal Neurological Institute space; then, collateral vessels were measured on MRA and classified into 3 types of anastomosis according to the parent artery: lenticulostriate, thalamic, and choroidal. We also obtained the coordinates of collateral vessel outflow to the cortex. Differences in cortical terminations were compared among the 3 types of anastomosis. RESULTS: We investigated 219 patients with Moyamoya disease, and a total of 190 collateral vessels (lenticulostriate anastomosis, n = 72; thalamic anastomosis, n = 21; choroidal anastomosis, n = 97) in 46 patients met the inclusion criteria. We classified the distribution patterns of collateral anastomosis as follows: lenticulostriate collaterals outflowing anteriorly (P < .001; 95% CI, 67.0-87.0) and medially (P < .001; 95% CI, 11.0-24.0) more frequently than choroidal collaterals; lenticulostriate collaterals outflowing anteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 34.0-68.0); and choroidal collaterals outflowing posteriorly more frequently than thalamic collaterals (P < .001; 95% CI, 14.0-34.0). Lenticulostriate anastomoses outflowed to the superior or inferior frontal sulcus and interhemispheric fissure. Thalamic anastomoses outflowed to the insular cortex and cortex around the central sulcus. Choroidal anastomoses outflowed to the cortex posterior to the central sulcus and the insular cortex. CONCLUSIONS: Cortical distribution patterns appear to differ markedly among the 3 types of collaterals.


Assuntos
Córtex Cerebral/irrigação sanguínea , Circulação Colateral , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/patologia , Adulto , Angiografia Cerebral/métodos , Córtex Cerebral/diagnóstico por imagem , Estudos Transversais , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Japão , Angiografia por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos
7.
J Neurosci ; 21(23): 9377-86, 2001 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11717371

RESUMO

In human, both primary and nonprimary motor areas are involved in the control of voluntary movements. However, the dynamics of functional coupling among different motor areas has not been fully clarified yet. Because it has been proposed that the functional coupling among cortical areas might be achieved by the synchronization of oscillatory activity, we investigated the electrocorticographic coherence between the supplementary motor and primary sensorimotor areas (SMA and S1-M1) by means of event-related partial coherence analysis in 11 intractable epilepsy patients. We found premovement increase of coherence between the SMA proper and S1-M1 at the frequency of 0-33 Hz and between the pre-SMA and S1-M1 at 0-18 Hz. Coherence between the SMA proper and M1 started to increase 0.9 sec before the movement onset and peaked 0.3 sec after the movement. There was no systematic difference within the SMA (SMA proper vs pre-SMA) or within the S1-M1, in terms of the time course as well as the peak value of coherence. The phase spectra revealed near-zero phase difference in 57% (20 of 35) of region pairs analyzed, and the remaining pairs showed inconsistent results. This increase of synchronization between multiple motor areas in the preparation and execution of voluntary movements may reflect the multiregional functional interactions in human motor behavior.


Assuntos
Relógios Biológicos , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiopatologia , Movimento , Volição , Adolescente , Adulto , Neoplasias Encefálicas/fisiopatologia , Estimulação Elétrica , Eletrodos Implantados , Eletroencefalografia/métodos , Eletromiografia , Epilepsia/fisiopatologia , Potenciais Evocados , Potenciais Somatossensoriais Evocados , Feminino , Dedos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Processamento de Sinais Assistido por Computador , Córtex Somatossensorial/fisiopatologia , Punho
8.
Gene ; 106(1): 135-6, 1991 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-1937035

RESUMO

The nucleotide sequence of the downstream flanking region of the mreD gene of Escherichia coli was determined. Two open reading frames (ORFs) were found, a 591-bp orfE and a 1467-bp orfF. Based on the sequence, it is suggested that the three mre genes (encoding the murein pathway), mreB, mreC and mreD, and these two ORFs possibly form an operon.


Assuntos
Escherichia coli/genética , Genes Bacterianos , Peptidoglicano/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Bacteriano , Dados de Sequência Molecular , Fases de Leitura Aberta , Peptidoglicano/metabolismo , Plasmídeos , Alinhamento de Sequência
9.
FEBS Lett ; 221(1): 167-71, 1987 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-3305073

RESUMO

A new beta-lactam-inducible penicillin-binding protein (PBP) that has extremely low affinity to penicillin and most other beta-lactam antibiotics has been widely found in highly beta-lactam(methicillin)-resistant Staphylococcus aureus (MRSA). The gene for this protein was sequenced and the nucleotide sequence in its promoter and close upstream area was found to show close similarity with that of staphylococcal penicillinase, while the amino acid sequence over a wide range of the molecule was found to be similar to those of two PBPs of Escherichia coli, the shape-determining protein (PBP 2) and septum-forming one (PBP 3). Probably the MRSA PBP (Mr 76462) evolved by recombination of two genes: an inducible type I penicillinase gene and a PBP gene of a bacterium, causing the formation of a beta-lactam-inducible MRSA PBP.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte/genética , Hexosiltransferases , Meticilina , Muramilpentapeptídeo Carboxipeptidase/genética , Resistência às Penicilinas , Peptidil Transferases , Recombinação Genética , Staphylococcus aureus/genética , Antibacterianos/farmacologia , Composição de Bases , Sequência de Bases , DNA Bacteriano/genética , Escherichia coli/genética , Genes Reguladores , Hibridização de Ácido Nucleico , Proteínas de Ligação às Penicilinas , Penicilinase/genética , Regiões Promotoras Genéticas , Homologia de Sequência do Ácido Nucleico
10.
Biochem Pharmacol ; 39(1): 167-72, 1990 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-2153376

RESUMO

We previously reported on the inhibition of microtubule polymerization and the formation of ribbon structures by synthetic estrogens [Sato et al., J Biochem 101: 1247-1252, 1987]. The present investigation aimed to analyse these effects in vitro on stereochemical point of view, using hexestrol isomers ((R,R)-(+)-hexestrol, (S,S)-(-)-hexestrol and meso-hexestrol) and dl-hexestrol. Among hexestrols, dl-hexestrol showed the highest activity in ribbon formation from microtubule proteins at 100 microM. On the other hand, meso-hexestrol was distinguished from others by inhibition of microtubule assembly and formation of a large amount of aggregates from purified tubulin in the presence of MgCl2 and DMSO. These results were discussed with physico-chemical properties of hexestrols, e.g. absolute configurations as well as circular dichroism spectra and solid state carbon-13 nuclear magnetic resonance spectra.


Assuntos
Hexestrol/farmacologia , Proteínas dos Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Animais , Encéfalo/ultraestrutura , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica , Microtúbulos/efeitos dos fármacos , Conformação Molecular , Estrutura Molecular , Polímeros , Estereoisomerismo , Relação Estrutura-Atividade , Suínos , Tubulina (Proteína)/metabolismo
11.
J Biochem ; 104(5): 822-6, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3148617

RESUMO

We determined the active site of penicillin-binding protein (PBP) 2 of Escherichia coli. A water-soluble form of PBP 2, which was constructed by site-directed mutagenesis, was purified by affinity chromatography, labeled with dansyl-penicillin, and then digested with a combination of proteases. The amino acid composition of the labeled chymotryptic peptide purified by HPLC was identical with that of the amino acid sequence, Ala-Thr-Gln-Gly-Val-Tyr-Pro-Pro-Ala-Ser330-Thr-Val-Lys-Pro (residues 321-334) of PBP 2, which was deduced from the nucleotide sequence of the pbpA gene encoding PBP 2. This amino acid sequence was verified by sequencing the labeled tryptic peptide containing the labeled chymotryptic peptide region. A mutant PBP 2 (thiol-PBP 2), constructed by site-directed mutagenesis to replace Ser330 with Cys, lacked the penicillin-binding activity. These findings provided evidence that Ser330 near the middle of the primary structure of PBP 2 is the penicillin-binding active-site residue, as predicted previously on the basis of the sequence homology. Around this active site, the sequence Ser-Xaa-Xaa-Lys was observed, which is conserved in the active-site regions of all E. coli PBPs so far studied, class A and class C beta-lactamases, and D-Ala carboxypeptidases. The COOH-terminal amino acid of PBP 2 was identified as His633.


Assuntos
Aciltransferases/genética , Proteínas de Bactérias , Proteínas de Transporte , Hexosiltransferases/genética , Complexos Multienzimáticos/genética , Muramilpentapeptídeo Carboxipeptidase , Peptidil Transferases/genética , Sequência de Aminoácidos , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Quimotripsina/metabolismo , Escherichia coli/genética , Hexosiltransferases/metabolismo , Dados de Sequência Molecular , Complexos Multienzimáticos/metabolismo , Mutação , Proteínas de Ligação às Penicilinas , Penicilinas/metabolismo , Peptidil Transferases/metabolismo , Serina , Tripsina/metabolismo
12.
Microb Drug Resist ; 2(1): 91-3, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9158728

RESUMO

The effects of bacterial masses upon the drug resistance of neighboring bacteria were investigated. The experiments were performed with plastic Petri dishes divided into two identical compartments. A growing mass of Bacillus subtilis (signal emitter cell) in one compartment exerted enhancing effects upon the erythromycin and streptomycin resistance of Bacillus carboniphilus (signal recipient) cells, sparsely seeded in the other compartment, through the plastic wall and the air. These effects of the growing mass of cells are attributed to the emission of "sonic" signals.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Meios de Cultura , Eritromicina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/ultraestrutura , Estreptomicina/farmacologia
13.
Urology ; 27(4): 309-17, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3962054

RESUMO

In an attempt to develop as objective a method for the evaluation of impotence as possible, the authors assigned numerical values to four parameters considered essential to sexual function, namely, libido, erection, ejaculation, and orgasm, and used the sum totals of these scores, collected before and after initiation of therapy, as indicators of overall sexual function. Numerical values were assigned according to a logarithmic scale, in four stages from 0 to 10, i.e., 0, 1, 3, and 10; a score of 0 signified "normal" and a score of 10, "abnormal." By comparing sum totals of scores computed before and after initiation of therapy, the authors were able to evaluate therapeutic efficacy on the basis of changes in these sum totals. Using this method, the mean total score for a control group of 24 normal subjects was 1.67 +/- 0.26 (mean +/- standard error). For the test group, which consisted of 24 patients of psychogenic impotence, the mean total score prior to initiation of therapy was 16.46 +/- 3.55, an extremely high score in comparison with the control group. After four weeks of therapy, the mean total score dropped to 9.37 +/- 1.77, indicating a statistically significant (p less than 0.05) decrease over the pre-therapy mean total score.


Assuntos
Disfunção Erétil/diagnóstico , Adulto , Ejaculação , Disfunção Erétil/etiologia , Disfunção Erétil/terapia , Estudos de Avaliação como Assunto , Humanos , Infertilidade Masculina , Libido , Masculino , Pessoa de Meia-Idade , Orgasmo , Ereção Peniana , Inquéritos e Questionários
14.
Urology ; 32(3): 269-72, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3046104

RESUMO

A case of primary carcinoma of the seminal vesicle in a nineteen-year-old man is described. This patient represents the twelfth case reported in the literature in Japan. The experience gained in this case indicated the potential usefulness of ultrasonography in the diagnosis of primary carcinoma of the seminal vesicle.


Assuntos
Adenocarcinoma Papilar/diagnóstico , Neoplasias dos Genitais Masculinos/diagnóstico , Glândulas Seminais/patologia , Ultrassonografia , Adenocarcinoma Papilar/patologia , Adenocarcinoma Papilar/cirurgia , Adulto , Neoplasias dos Genitais Masculinos/patologia , Neoplasias dos Genitais Masculinos/cirurgia , Humanos , Masculino , Glândulas Seminais/cirurgia
15.
Urology ; 30(2): 180-2, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3617307

RESUMO

Bilateral and synchronous testicular tumors consisting of different cell types on each side are rare. We describe one additional case of synchronous bilateral testicular tumors comprised of different cell types on each side and review the relative literature.


Assuntos
Cisto Dermoide/patologia , Disgerminoma/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Testiculares/patologia , Testículo/patologia , Adulto , Humanos , Masculino
16.
Clin Neurophysiol ; 115(9): 2056-65, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15294208

RESUMO

OBJECTIVE: To locate the visual motion complex (MT+) and study its response properties in an epilepsy surgery patient. METHODS: A 17-year-old epilepsy patient underwent invasive monitoring with subdural electrodes in the right temporo-parieto-occipital area. MT+ was investigated by cortical electric stimulation and by epicortical visual evoked potentials time-locked to motion onset of sinusoidal gratings (motion VEP). Motion-related visual evoked magnetic field (motion VEF) was also recorded before the electrode implantation to complement the invasive recording. RESULTS: Motion VEPs revealed two subregions within MT+, generating early and late potentials respectively. The early activity with a peak around 130 ms was localized at a single electrode situated immediately caudal to the initial portion of the ascending limb of the superior temporal sulcus (AL-STS). The late activity, peaking at 242-274 ms, was located ventro-rostrally over three electrodes. Among the four electrodes with motion VEPs, cortical stimulation at the most caudal pair elicited motion-in-depth perception involving the whole visual field. In addition to two subregions revealed on the gyral crown, magnetoencephalography (MEG) demonstrated another subregion with a late motion VEF in AL-STS immediately rostral to the electrode with the early motion VEP. CONCLUSIONS: In combination with MEG recording, the present invasive exploration demonstrated human MT+ in a focal area of the temporo-parieto-occipital junction and delineated possible three subregions as indicated by the different latencies and distributions of the motion VEP/VEFs. SIGNIFICANCE: Comparative MEG and direct electrocorticographic recordings delineated possible subregions within the human MT complex.


Assuntos
Potenciais Evocados Visuais/fisiologia , Magnetoencefalografia , Percepção de Movimento/fisiologia , Córtex Visual/fisiologia , Adolescente , Estimulação Elétrica , Eletrodos Implantados , Eletroencefalografia , Epilepsia Parcial Complexa/fisiopatologia , Humanos , Masculino , Lobo Parietal/fisiologia , Espaço Subdural , Lobo Temporal/fisiologia
17.
Clin Neurophysiol ; 113(9): 1470-84, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12169330

RESUMO

OBJECTIVES: To elucidate the maturational change of cortical auditory processing, we analyzed simultaneously recorded auditory evoked potentials (AEPs) and magnetic fields (AEFs) in school-aged children. METHODS: Simultaneous recording of AEP and AEF were performed in 32 healthy children of age ranging from 6 to 14 years and 10 adults. Tone bursts of 1 kHz were presented to the left and right ears alternately with 3 different within-ear stimulus onset asynchronies (SOAs) (1.6, 3.0 and 5.0 s for each ear) under attention-distracted condition. RESULTS: All subjects showed clear N100 and N100m peaks under the longest SOA condition (5.0 s). Under the shortest SOA condition (1.6 s), 4 out of 19 subjects under 12 years (21%) failed to show the N100m component. By contrast, N250 and N250m were observed in the majority of children (29/32: 91%) while those were detected in only 4 out of 10 adults (40%). The spatial distribution of N100 in children under 9 years differed from that in older subjects, whereas the dipole orientation of N100m was constant among age groups, suggesting that radially oriented sources might make additional contribution to the generation of N100 in early childhood. N250 was significantly larger in children than in adults. The strength of N250 was suppressed with longer SOAs, whereas that of N100 was enhanced. The dipole of N250m was located around Heschl's gyrus on the superior temporal plane which was significantly medial, anterior and inferior to that of N100m. CONCLUSIONS: Dissociation of maturational change between the tangential and radial components of N100 suggests that auditory processing at around 100 ms consists of multiple parallel pathways which mature independently. Furthermore, a negative peak at around 250 ms specifically seen in children has different generators from N100 and might represent a special auditory processing which takes an active part until acquisition of the efficient cortical networks of the adult brain.


Assuntos
Envelhecimento/fisiologia , Percepção Auditiva/fisiologia , Córtex Cerebral/fisiologia , Potenciais Evocados Auditivos/fisiologia , Estimulação Acústica , Adolescente , Adulto , Fatores Etários , Vias Auditivas/fisiologia , Mapeamento Encefálico , Criança , Eletroencefalografia , Eletroculografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Tempo de Reação/fisiologia , Valores de Referência
18.
Am J Ophthalmol ; 95(2): 182-8, 1983 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6824050

RESUMO

The noninvasive laser Doppler technique was used to study retinal circulatory characteristics in five patients who underwent uncomplicated scleral buckling procedures. In each patient, the systolic/diastolic variation of the red blood cell speed in the retinal arteries (flow pulsatility ratio) was lower in the eye that had received an intrascleral implant and an encircling band than in the fellow eye. In one patient, an increase in flow pulsatility ratio accompanied an increase in retinal blood flow after removal of the scleral buckling elements. In another patient, the flow pulsatility ratio in the eye that had received a solid implant and an encircling band was less than the ratio in the fellow eye that had received an absorbable implant alone. Our results indicated that reduced retinal blood flow may be common after scleral buckling procedures, and may be a significant factor in otherwise inexplicable postoperative complications.


Assuntos
Retina/irrigação sanguínea , Recurvamento da Esclera , Adulto , Feminino , Humanos , Lasers , Masculino , Pessoa de Meia-Idade
19.
Sci Prog ; 77 ( Pt 3-4): 253-64, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-7725080

RESUMO

Expression of the cafA gene at 71 min on the E. coli chromosome map by use of a high copy number expression vector caused (1) overproduction of the 51 kDa CafA protein, (2) formation of chains of normal cells and shorter anucleate cells, and (3) formation of flexible, tough structures, which we call 'cytoplasmic axial filaments', running throughout the centre of the chained cells. In this article we shall describe the morphology, physiology and possible functions of the cytoplasmic axial filament structure. This structure could be a strong candidate for one of the procaryotic cytoskeletal/cytokinetic elements functioning in cellular extension and division, chromosomal segregation and other important mechanisms involved in the proliferation of procaryotic cells.


Assuntos
Proteínas de Bactérias/genética , Divisão Celular/genética , Cromossomos Bacterianos , Citoesqueleto/genética , Escherichia coli/genética , Sequência de Aminoácidos , Cromossomos Bacterianos/ultraestrutura , Clonagem Molecular , Citoesqueleto/ultraestrutura , Escherichia coli/ultraestrutura , Humanos , Microscopia Eletrônica , Dados de Sequência Molecular , Software
20.
J Antibiot (Tokyo) ; 31(12): 1292-5, 1978 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-368000

RESUMO

The affinities of cefoxitin, a cephamycin antibiotic, to penicillin-binding proteins of Escherichia coli were reexamined using a recently developed method for separating penicillin-binding proteins. The inhibitions by this antibiotic of four measurable penicillin-sensitive enzymatic reactions, the reactions of D-alanine carboxypeptidases IA and IB, cross-bridge formation and concomitant release of D-alanine, were also measured. An approximate correlation was found between the affinities of cefoxitin to the penicillin-binding proteins responsible for these reactions and its rates of inhibition of the respective penicillin-sensitive reactions.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Cefoxitina/farmacologia , Cefalosporinas/farmacologia , Escherichia coli/efeitos dos fármacos , Penicilinas/metabolismo , Ligação Competitiva , Cefoxitina/metabolismo , Escherichia coli/metabolismo , Penicilina G/metabolismo , Penicilinas/antagonistas & inibidores , Ligação Proteica
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