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Biomedical subjects

T Nagamine

Publications and source records attributed to T Nagamine.

At least 199 records · Page 11Linked to original sources
PubMed1995

Intracellular transduction in the regulation of pheromone biosynthesis of the silkworm, Bombyx mori: suggested involvement of calmodulin and phosphoprotein phosphatase.

We have tested the effects of chemicals on bombykol production in vitro in the silkworm, Bombyx mori, to probe the biochemical steps as well as underlying mechanisms regulated by PBAN. These results suggest the involvement of calmodulin and phosphoprotein phosphatase in the intracellular signal transduction of PBAN action.

Amino Acid Sequence↗
PubMed1995

Increase in serum interleukin-6, plasma ACTH and serum cortisol levels after systemic interferon-alpha administration.

Systemic administration of human interferon-alpha stimulates the pituitary-adrenal axis in men, but the exact mechanism still remains to be established. The present study was undertaken to examine the hypothesis that interferon-alpha may alter the circulating concentrations of the cytokines which involve the activation of the pituitary-adrenal axis. Eleven patients with chronically active hepatitis C were treated with human lymphoblastoid interferon-alpha (IFN: 6 x 10(6) IU/day) and changes in plasma adrenocorticotropin (ACTH), serum cortisol and cytokine concentrations were observed on both the first and second days of the treatment. Subcutaneous administration of IFN significantly increased plasma ACTH and serum cortisol concentrations by 3 h after the injection. Serum interleukin-6 (IL-6) increased with the increase in circulating ACTH and cortisol. There was a significant correlation between serum cortisol and IL-6 concentrations at 3 h. In contrast, an increase in serum interleukin-1 beta was only observed in one case. On the second day of IFN treatment, simultaneous administration of 25 mg diclofenac sodium eliminated the IFN effects on circulating ACTH, cortisol and IL-6 concentrations. The present studies demonstrated that circulating IL-6 increases after systemic IFN administration, resulting in activation of the pituitary-adrenal axis.

Adrenocorticotropic Hormone↗
PubMed1995

Type II citrullinemia associated with neutropenia.

A 37-year-old Japanese man was admitted with delirium and hyperammonemia. He was diagnosed as having type II citrullinemia because of an elevated citrulline level on amino acid analysis and very low hepatic argininosuccinate synthetase activity. He also showed a low neutrophil count and a low serum level of granulocyte colony-stimulating factor. Reduced production of this cytokine and/or impairment of its feedback regulation by the neutrophil count may have played a role in the neutropenia of this patient.

Adult↗
PubMed1995

[Surgical repair of complete atrioventricular septal defect: annuloplasty by using a smaller VSD patch].

Recent policy for the intracardiac repair of complete atrioventricular septal defect (CAVSD) is demonstrated on the basis of the following theoretical background. In the normal heart, the originating portion of the ascending aorta and the crux intrude between the mitral and tricuspid orifices each from the anterior and from the posterior, separating both the orifices together with a short fibrous septal junction. In CAVSD, however, the common A-V orifice takes an elliptic form without any septal junction. It is considered beneficial, therefore, to surgically produce a short septal junction by using a smaller patch to close the ventricular portion of the AVSD. When the left lateral leaflet is larger, two leaflets valve plasty is suggested and when it is smaller, three leaflets valve plasty is suggested to reconstruct the left-sided A-V valve, although competence of the valve leaflets must be finally secured by doing repeated water injection tests. The size of the orifices of the reconstructed left-sided as well as right-sided A-V valve should also be confirmed not to be stenotic by using Hegar sizers. Since 1991, we have applied this surgical concept in 7 patients with CAVSD. Postoperatively, there was no left A-V valve regurgitation in one and slight regurgitation remained in 6 patients. The result is considered to be satisfactory. Although one patient died due to PH crisis, the cause of death was not related to valve regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1994

Inhibition of free radical generation by biotin.

To assess the inhibitory effect of biotin on free radical generation, we used a spectrophotometric assay of cytochrome c reduction and determined the 2-methyl-6-phenyl-3,7-dihydroimidazo[1,3-a]-pyrazin-3-one (CLA)-dependent chemiluminescence response of human neutrophils or a hypoxanthine-xanthine oxidase (XOD) system. In the spectrophotometric assay of cytochrome c reduction, superoxide (O2-) generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (f-MLP) was reduced significantly when biotin was added. In the CLA-dependent chemiluminescence test of neutrophils stimulated by f-MLP, biotin significantly reduced the generation of free radical species, including O2-, in a concentration-dependent manner, the concentration corresponding to 50% inhibition (IC50) of biotin for free radical generation was 1.12 x 10(-7) mol. However, biotin did not exert an inhibitory effect on oxidative metabolism by directly scavenging superoxide anion, as shown by the study using the hypoxanthine-XOD system.

Adult↗
PubMed1994

Cortical magnetic and electric fields associated with voluntary finger movements.

Multichannel recordings of both movement-related magnetic fields (MRMFs) and movement-related cortical potentials (MRCPs) were simultaneously recorded in association with voluntary unilateral self-paced index finger abduction movement in two normal volunteers. 1) Slow magnetic field (readiness field; RF) can be detected several hundred msec before the movement onset, and its field distribution indicates the existence of the largest generator source over the contralateral primary motor area. Taken together with the vertex-maximal Bereitschaftspotential which corresponds to the earlier part of the RF, the complexity of this magnetic field suggested by relatively low correlation value in single dipole model indicates the co-activation of other underlying generators besides this largest dipole. 2) The utilization of MRMF with MRCP facilitates the separation of two distinct electrophysiological events in proximity to the movement onset, which are difficult to be determined by the technique of MRCP only. Those are the motor field (MF) and the movement evoked field I (MEFI) in MRMF, and the parietal peak motor potential (ppMP) and the frontal peak motor potential (fpMP) in MRCP, which occur approximately 20 and 100 msec after EMG onset, respectively. These two subcomponents may imply the culmination of motor cortex and sensory feedback activation, respectively. Combined study of MRMF and MRCP will provide better definition of cortical events related to voluntary movement than the study of either modality alone.

Adult↗
PubMed1994

Elevation of N1-acetylspermidine and putrescine in hepatic tissues of patients with fulminant hepatitis and liver cirrhosis.

Hepatic polyamines were assayed in 15 patients with liver diseases, 5 with fulminant hepatitis (FH); 3 with exacerbated liver cirrhosis (ELC); and 7 with liver cirrhosis (LC). Hepatic putrescine and N1-acetylspermidine as percentages of total polyamines, were elevated and spermine was decreased in all 15 patients. The increase in hepatic N1-acetylspermidine levels appeared to be greater in patients with FH and ELC than in those with LC. These results suggest that the production of N1-acetylspermidine in human liver is closely associated with the induction of spermidine/spermine N1-acetyltransferase activity in liver diseases.

Acetyltransferases↗
PubMed1994

Clinical evaluation of biotin-binding immunoglobulin in patients with Graves' disease.

Biotin-binding immunoglobulin (BBI) was recently identified in human serum and has been suggested to have a significant association with allergic and autoimmune disorders. Attempts were made to evaluate the clinical significance of BBI in autoimmune thyroid disorders. Prevalence of BBI was significantly higher in Graves' disease (47%) than in Hashimoto's disease (8%) and healthy controls (10%). The BBI consisted of heterogeneous subtypes with respect to binding of several immunoglobulin classes. Sera in Graves' disease showed predominantly IgG-binding BBI, whereas healthy subjects had IgM-binding BBI. Thyroid stimulating hormone receptor antibody (TRAb) level was significantly higher in the BBI non-detected group than in the detected group. There was no significant relationship between BBI prevalence and thyroid hormone concentrations, anti-thyroglobulin antibody (TGAb) or anti-thyroid microsomal antibody (McAb) titers. In addition, biotin levels in peripheral blood and red blood cells and biotinidase activity did not differ in the BBI detected and non-detected groups. The present results suggest that BBI is associated with autoimmune dysfunction in Graves' disease.

Adult↗
PubMed1994

Dissociation between contingent negative variation and Bereitschaftspotential in a patient with cerebellar efferent lesion.

Contingent negative variation (CNV) and Bereitschaftspotential (BP) were from the scalp in a patient with a discrete infarct in the mesial tegmentum of the midbrain involving the decussation of the superior cerebellar peduncle. Bereitschaftspotential in association with hand movements was completely absent while CNV was normally present at the frontocentral midline. This indicates that CNV is, as opposed to BP, generated without cerebro-cerebellar interactivation, suggesting different generating mechanisms.

Cerebellar Diseases↗
PubMed1994

Formulation of inactivated influenza vaccines for providing effective cross-protection by intranasal vaccination in mice.

Attempts were made to formulate an inactivated influenza vaccine to provide effective cross-protection by intranasal vaccination in mice. Mice were immunized with a nasal site-restricted volume of various HA vaccines (split-product virus vaccines), prepared from some of the H1N1 subtype viruses which circulated in humans from 1934 to 1986, together with cholera toxin B subunit (CTB) as an adjuvant. Four weeks later, they were challenged intranasally with a lethal dose of the earliest H1N1 virus strain, A/PR/8/34 (PR8) or the latest virus strain, A/Yamagata/120/86 (Yamagata/86). The adjuvant-combined vaccines, prepared from drift H1N1 viruses, A/Kumamoto/37/79 and A/Bangkok/10/83, provided a higher degree of cross-protection against a challenge with Yamagata/86 than with PR8. A booster with another drift virus vaccine given 4 weeks after the primary vaccination increased the protection against Yamagata/86; the effect was higher when mice were vaccinated with a later strain as the second antigen than when boosted with PR8. These results suggest that vaccination with a later virus strain followed by another later strain in a two-dose nasal vaccination regimen gives effective cross-protection against the current epidemic virus strains.

Administration, Intranasal↗
PubMed1994

Synergistic action of cholera toxin B subunit (and Escherichia coli heat-labile toxin B subunit) and a trace amount of cholera whole toxin as an adjuvant for nasal influenza vaccine.

Cholera toxin B subunit (CTB) and Escherichia coli heat-labile toxin (LTB) (2 micrograms), each supplemented with a trace amount of cholera toxin (CT) (0.02-20 ng), were examined for the adjuvant effect on antibody (Ab) response against influenza inactivated HA (haemagglutinin) vaccine in Balb/c mice. Each mouse received a primary intranasal (i.n.) inoculation of the vaccine (1.5 micrograms) and the CT-containing CTB and in 4 weeks a second i.n. inoculation of the vaccine alone. The primary inoculation of the vaccine with CTB alone did not induce either anti-HA IgA or IgG Ab response, or haemagglutination-inhibition Ab responses in the serum. The vaccine with less than 2 ng of CT also failed to induce Ab response. On the other hand, the vaccine with CT-containing CTB induced a high Ab response, which increased depending on the CT dose. Moreover, the second vaccine induced a response more than ten times higher than the primary one and the response increased depending on the CT dose. Similar enhancement was found in the local anti-HA IgA Ab response in the nasal wash. Such synergistic effects were observed also between LTB and CT. The amount of Ab produced by the synergism was considered to be enough to protect against virus infection. These results suggest that CTB (or LTB) containing a trace amount of CT (about 0.1%) can be used practically as a potent adjuvant for nasal vaccination of humans against influenza.

Adjuvants, Immunologic↗
PubMed1994

Escherichia coli heat-labile enterotoxin B subunits supplemented with a trace amount of the holotoxin as an adjuvant for nasal influenza vaccine.

Escherichia coli heat-labile enterotoxin B subunit (LTB) (2 micrograms), supplemented with a trace amount of the holotoxin (LT) (0.02-20 ng), was examined for the adjuvant effect on antibody (Ab) responses against influenza inactivated haemagglutinin (HA) vaccine in Balb/c mice. Each mouse received a primary intranasal (i.n.) inoculation with the vaccine (1.5 micrograms), prepared from PR8 (H1N1) virus, together with LT-containing LTB and in 4 weeks a second i.n. inoculation of the vaccine alone. The inoculation of the vaccine with the LT-containing LTB induced significantly high primary and secondary anti-HA IgA and IgG Ab responses in the nasal wash and the serum, while the vaccine with LTB or less than 2 ng of LT induced little response. The synergistic adjuvant effect was maximal in the concentration of LTB supplemented with 0.2-2 ng of LT. Under these conditions, the augmented IgA and IgG Ab responses, which are cross-protective to PR8 HA molecules, provided complete cross-protection against PR8 virus challenge in mice immunized with heterologous vaccine within the same subtype. These results suggest that LTB containing a trace amount of LT can be used as a potent adjuvant for nasal vaccination of humans against influenza.

Adjuvants, Immunologic↗
PubMed1994

Automatic detection method of P300 waveform in the single sweep records by using a neural network.

Event-related potentials (ERPs) are responses related to the recognition of certain stimuli. P300 is the most important positive component in the ERP and appears around 300 ms after the target stimulus in the oddball paradigm. In our previous work, we proposed a method for the automatic detection of the P300 waveform in single-sweep records by using a correlation technique. However, determination of the threshold values of the P300 waveform for the correlation study was not an easy task. In skirting this problem, we developed an automatic method of detecting a single-sweep P300 waveform by using an artificial neural network. We selected appropriate characteristic parameters of positive peaks as input signals for the input layer units, and the weights between the layers were determined by using the back-propagation algorithm. The neural network for P300 detection was obtained automatically, based on the data of ERPs obtained from 11 healthy males, and gave substantial accuracy for P300 detection. Furthermore, by using this neural network we clarified the way in which the P300 waveform is judged visually by each inspector.

Acoustic Stimulation↗
PubMed1994

Cortical reflex negative myoclonus.

Three patients with progressive myoclonic epilepsy (PME), two of them clinically manifesting only negative myoclonus and the other manifesting both positive and negative myoclonus, were electrophysiologically investigated, and compared with two other patients with PME presenting with only positive myoclonus. Electric stimulation of the median nerve during sustained active wrist extension in the three patients with negative myoclonus often elicited a short lapse of the posture in the stimulated hand associated with a silent period in the muscle discharge with or without being preceded by an abrupt increase in the muscle discharge (C reflex). The occurrence of the stimulus-induced silent period was significantly correlated with that of the giant somatosensory evoked potentials (SEPs), and in two patients the silent period was elicited also in the opposite (non-stimulated) hand when the giant SEP was recorded at the hemisphere ipsilateral to the stimulus as well. In one patient, the duration of the silent period was positively correlated with the amplitude of the cortical SEP. Furthermore, the duration of the induced silent period was closely related to the recovery function of SEP in each individual case. In contrast, in the two patients manifesting only positive myoclonus, the silent period was not elicited by the peripheral stimulation, and the somatosensory cortex was hyperexcitable immediately after the peripheral stimulus. Thus, this stimulus-sensitive negative myoclonus is mediated by a transcortical reflex mechanism, and corresponds to the negative form of the cortical reflex myoclonus ('cortical reflex negative myoclonus').

Adult↗
PubMed1994

Generator mechanism of pain-related evoked potentials following CO2 laser stimulation of the hand: scalp topography and effect of predictive warning signal.

In order to clarify the generator mechanism of pain-related evoked potentials (pain EPs), we studied the scalp topography of the pain EPs following CO2 laser stimulation of hand dorsum by using balanced sternovertebral electrodes as the noncephalic reference in 11 normal volunteers. We also examined the effects of predictive warning signal (light-emitting diode) on the pain EPs. In both the warned and unwarned conditions, all of the 22 hand stimulations showed a large negative component (N2) at the peak latency of about 213 ms followed by a large positive component (P2) at the peak latency of about 329 ms. A preceding small negative component (N1) at the peak latency of about 148 ms was detected in 12 of the 22 hand stimulations in the warned condition and in 13 of the 22 hand stimulations in the unwarned condition. P2 was significantly larger and occurred earlier in the warned condition than in the unwarned condition, whereas other components did not differ between the two conditions, suggesting that an increased attention of the subject to the stimulus influenced the generator mechanism of the P2 component. With regards to the scalp topography, N2 was maximal at Cz and widespread transversely to both sides, whereas P2 was maximal at Cz or Pz and spread more posteriorly than N2. These findings suggest that P2 is generated by a different mechanism from N2 and is most likely associated with pain-related cognitive function. N1 was localized to the contralateral central and midtemporal areas, confirming that the nociceptive inputs are perceived in the sensory cortex in humans. The question as to whether the N1 component is generated in the hand area of the primary somatosensory cortex or in the secondary somatosensory cortex, or in both areas, remains to be solved.

Adult↗
PubMed1994

Automatic detection of P300 in single sweep records of auditory event-related potential.

In the conventional recording of event-related potentials (ERPs) by the "oddball" paradigm, the subject may employ different strategies for processing one stimulus from the other even within the same session because of variable psychological state. Hence, "averaging" may not necessarily be suitable for recording ERP. We have therefore established a method for single trial recording of auditory ERPs by processing the EEG data through discrete Fourier transform followed by inverse discrete Fourier transform with the low pass filter of 8 Hz (digital filter). Each single sweep response of the processed data was visually evaluated as to whether it contained P300 or not by three investigators who were made completely blind with respect to the category of each response. As the result, a positive peak at a latency of 200-500 ms was recognized in the single sweep responses to target stimuli at a significantly greater frequency (40-60%) than in those to nontarget stimuli (0-18%). Then a new method for the automatic detection of P300 was established based on the data of 11 subjects belonging to the training group, by taking into account, in addition to the correlation coefficient analysis in which the template was computed specifically for each subject, other criteria with respect to the amplitude and waveforms, so that a good agreement with the results of visual inspection as to the presence or absence of P300 could be achieved for both target and nontarget responses. This automatic analysis method was successfully applied to five other subjects of the test group. The peak latency and amplitude of the detected positive peaks significantly varied among single target responses even within the same session. The reaction time significantly correlated positively with the peak latency of the detected positive peaks and negatively with the amplitude of those peaks, supporting the usefulness of the present method.

Adult↗
PubMed1994

Optimisation of botulinum treatment for cervical and axial dystonias: experience with a Japanese type A toxin.

Twenty two patients with cervical and axial dystonias were treated with Japanese type A botulinum toxin. Injections were given repeatedly at intervals of 28-30 days to carefully chosen muscles with increased activities, with a maximum dose per session of 300 units. The maximum improvements in subjective and objective ratings were obtained only after repeated injections. No anti-toxin antibodies were detected; nor did any muscle fail to respond to the toxin. During the treatment, previously "silent" muscles were activated to reproduce the original abnormal posture, as if driven by a central motor programme. This resistance to treatment was overcome by injecting the toxin into newly activated muscles. Repeated injections are thus required to override central mechanisms in dystonias or to maximise drug delivery to large muscles. Antibody development may be controlled by the use of a less immunogenic toxin.

Adolescent↗