Biomedical subjects

A Naito

Publications and source records attributed to A Naito.

At least 91 records · Page 5Linked to original sources

PubMed1997

[Evaluation by visiting nurse in end-stage cancers--family questionnaire for patients who died after visiting nurse].

Since April 1994, we have provided visiting nurse care for patients with end-stage of cancers. A questionnaire was sent to 72 families of patients who died of cancer and who received after visiting nurse care. The response rate to the questionnaire was 76.4% (55 patients). One group of 27 patients died at home (Group A), and the other group of 28 patients died in the hospital (Group B). Patients who knew they had cancer accounted for 85.2% in Group A, and 57.1% in Group B. Of all patients, 69.1% desired home nursing, with 77.8% in Group A, and 60.7% in Group B. The satisfaction of families with the visiting nurse was evaluated. In Group A, satisfaction was 66.7% and relative satisfaction was 18.5%. In Group B, satisfaction was 50.0% and relative satisfaction was 25.0%. Satisfaction of patients with the place of death was 81.5% in Group A, and 35.7% in Group B. Many families wished to have the nurse visit 2 times a week, and an hour at each visit. The great mental burden on the families who provide home care for patients with terminal cancer was clear for the questionnaire. Arrangement for a support system for patients and families, through visiting nurse services, is necessary in our hospital.

Community Health Nursing↗

PubMed1996

Temperature-dependent conformational change of bacteriorhodopsin as studied by solid-state 13C NMR.

Cross-polarization and dipolar-decoupled magic-angle spinning 13C-NMR spectra of [3-13C]Ala-labelled bacteriorhodopsin were obtained for hydrated purple membrane in the temperatures range 23 degrees C to -110 degrees C. Well-resolved 13C-NMR signals were observed either at ambient temperature or at -20 degrees C but were broadened considerably at lower temperature below -40 degrees C. This situation was interpreted in terms of the presence of exchange processes with a rate constant of 10(2) s-1 at ambient temperature among several conformations slightly different from each other. We found that such an exchange process was strongly influenced by the manner of organization of the lipid bilayers depending upon the presence or absence of cations responsible for electric shielding of negative charge at the polar head groups. The manner of organization of the lipid bilayers was conveniently characterized by a characteristic temperature at which the methyl peaks of fatty acyl groups of lipids in the purple membrane were suppressed due to interference of motional frequency with the decoupling frequency (10-100 kHz) for preparations containing 10 mM NaCl or CaCl2. No such spectral change in the absence of these cations was noted even if a preparation was cooled to -110 degrees C. The secondary structures of [3-13C]Ala-labelled bacteriorhodopsin was not always identical at temperatures between ambient and low temperatures, since the 13C chemical shifts and relative peak intensities for purple membrane preparations containing these salts changed with temperature in the range -110 degrees C to 23 degrees C. In particular, we found that some residues involving Ala residues at the alpha II-helix and loop region were converted at temperatures below -60 degrees C to a conformation involving alpha 1-helix. In other words, some portion of the alpha-helical conformation of bacteriorhodopsin proposed from results obtained by cryo-electron microscopy, at very low temperatures, is not always retained at ambient temperature.

Alanine↗

PubMed1996

Conformation and dynamics of [3-13C]Ala- labeled bacteriorhodopsin and bacterioopsin, induced by interaction with retinal and its analogs, as studied by 13C nuclear magnetic resonance.

13C nuclear magnetic resonance (NMR) spectra of [3-13C]Ala-labeled bacteriorhodopsin (bR), bacterioopsin (bO), and regenerated bR with retinal or bO complex with retinal analogs were recorded in order to gain insights into how the conformation and dynamics of apoprotein (bO) vary with or without retinal or its analogs. First, we assigned the 13C NMR peak resonating at 16.3 ppm to Ala 53 of both bR and bO, which appears to contact the side chain of Lys 216 at the site of the Schiff base in the former, utilizing the 13C NMR peaks of A53V and A53G proteins in comparison with those of wild-type bR and bO. Characteristic spectral differences between the apoprotein and bR were observed upon removal of the retinal: the changes of the peak intensities at 16.4, 15.9, and 16.9 ppm are notable. We found that the loops (17.4 ppm) and transmembrane alpha II helical region (15.9 ppm) acquired motional freedom with a correlation time of 10(-5)s when the retinal was removed, as detected by proton spin-lattice relaxation times in the rotating frame. A 13C NMR spectrum very similar to that of native bR was recorded when bR was regenerated by addition of retinal to bO. On the other hand, the addition of the retinal analogs retinol or beta-ionone, which are bound in the retinal binding site but are incapable of forming a Schiff base to the apoprotein, caused distinct spectral changes different from those of bR, as manifested from the displacements of 13C chemical shifts. These spectral changes must be ascribed to significant conformational changes of apoprotein at various locations in the protein, including the site of Ala 53 induced by modified interaction between the apoprotein and chromophore.

Alanine↗

PubMed1996

Dynamics of the three methionyl side chains of Streptomyces subtilisin inhibitor. Deuterium NMR studies in solution and in the solid state.

Streptomyces subtilisin inhibitor (SSI) contains three methionine residues in a subunit: two (at positions 73 and 70) in the crucial enzyme-recognition sites P1 and P4, respectively, and one (Met 103) in the hydrophobic core. The motions of the side chains of these three Met residues and the changes in mobility on binding with subtilisin were studied by deuterium NMR spectroscopy in solution and in crystalline and powder solids. For this purpose, the wild-type SSI was deuterium-labeled at the methyl groups of all three Met residues, and three artificial mutant proteins were labeled at only one specific Met methyl group each. In solution, for methionines 73 and 70, the effective correlation times were only 0.8-1.0 x 10(-10)s indicating that the two side chains on the surface fluctuate almost freely. On formation of a complex with subtilisin, however, these high mobilities were quenched, giving a correlation time of 1.1 x 10(-8)s for the side chains of methionines 70 and 73. The correlation time of Met 103, located in the hydrophobic core, was at least 1.0 x 10(-8)s in free SSI, showing that its side chain motion is highly restricted. The nature of the internal motions of the three Met side chains was examined in more detail by deuterium NMR spectroscopy of powder and crystalline samples. The spectral patterns of the powder samples depended critically on hydration: immediately after lyophilization, the side-chain motions of the three Met residues were nearly quenched. With gradual hydration to 0.20 gram of water per gram protein-water, the orientational fluctuation of the methyl axes of methionines 70 and 73 was selectively enhanced in both amplitude and frequency (to about 1 MHz) and, at nearly saturating hydration (0.60 gram of water per gram protein-water), became extremely high in amplitude and frequency (> 10 MHz). In contrast, the polycrystalline wild-type SSI spectrum showed fine structures, reflecting characteristic motions of the Met side chains. The polycrystalline spectrum could be reproduced reasonably well by the same motion models and parameters used to simulate the powder spectrum at the final level of hydration, suggesting that the side-chain motions are similar in the fully hydrated powder and in crystals. Spin-lattice relaxation measurements gave evidence that, even in crystals, the methyl axes of all three Met residues undergo rapid motions with correlation times between 10(-8) and 10(-10)s, comparable to the correlation times in solution. Finally, in the hydrated stoichiometric complex of SSI with subtilisin BPN' in the solid state, large-amplitude motions are absent, but the side chains of methionines 70 and/or 73 are likely to have small-amplitude motions.

Bacterial Proteins↗

PubMed1996

Inhibitory projection from brachioradialis to biceps brachii motoneurones in human.

Neural projection from the brachioradialis to the biceps brachii motoneurones in human was studied using the method of post-stimulus time histogram. Electrical stimulation to the radial branch innervating the brachioradialis produced inhibition in 11 out of 21 biceps motor units. The central delays of the inhibition were 0.7-1.2 ms longer than those of the homonymous facilitation. The inhibition was evoked with the intensity below the motor threshold. Pure cutaneous stimulation provoked no effects on the motor-unit firing. These findings suggest that group I afferents from the brachioradials mediate an oligosynaptic inhibition of the biceps brachii motoneurones.

Adult↗

PubMed1996

Early diagnosis and stage classification of vocal cord abductor paralysis in patients with multiple system atrophy.

OBJECTIVES: Vocal cord abductor paralysis (VCAP) is a life threatening complication which may cause nocturnal sudden death in patients with multiple system atrophy. However, the early diagnosis of VCAP is often difficult to make on routine laryngoscopy performed during wakefulness, as stridor, which is the sole symptom of VCAP in the early stage, develops only during sleep. The aim was to investigate laryngeal dysfunction in patients with multiple system atrophy while awake and asleep. METHODS: Seven patients with multiple system atrophy with nocturnal stridor and five control patients were studied. Vocal cord movement was analysed by laryngoscopy while the patients were awake and also during sleep induced by intravenous diazepam. RESULTS: When awake, for the seven patients with multiple system atrophy normal movement of the vocal cords occurred in three, mild abduction restriction in three, and paradoxical movement in one. When asleep, however, all showed obvious paradoxical movement with high pitched inspiratory stridor. In controls, there were no differences in the vocal cord movement between wakefulness and sleep. From these findings, VCAP could be divided into four stages: stage 0 (normal) with normal vocal cord movement during both wakefulness and sleep, stage 1 (mild VCAP) with normal movement during wakefulness and paradoxical movement during sleep, stage 2 (moderately severe VCAP) with abduction restriction during wakefulness and paradoxical movement during sleep, and stage 3 (severe VCAP) with an almost midline position for the vocal cords during both wakefulness and sleep. CONCLUSIONS: Laryngoscopy during sleep can disclose subclinical VCAP, making an early diagnosis of VCAP in patients with multiple system atrophy. Stage 2 of VCAP seems to be a suitable stage for tracheostomy in patients with multiple system atrophy.

Aged↗

PubMed1996

Fine structures of perikaryal myelin sheaths on statoacoustic ganglion cells in 3-day-old chicks.

Perikaryal myelin sheaths on statoacoustic ganglion cells in 3-day-old chicks were studied by electron microscopy. The fixation method with a high-concentrated warm fixative helped in successful demonstrations of perikaryal myelin structures. The sheaths were composed of loose and compact myelin mixed by various arrangements. Twenty-seven percent of perikarya were entirely encircled by compact myelin, 71% were partly wrapped by compact myelin, and 2% were wrapped by just loose myelin. The perikaryal myelin was composed of 3 to 16 layers of loose and compact lamellae, whereas the axonal myelin of 10 to 28 of compact lamellae. Since no unmyelinated perikarya, which are covered by a single layer of Schwann cell cytoplasm, were detected, it is suggested that the perikarya myelination on all the ganglion cells has started before 3 days after hatching.

Animals↗

PubMed1996

Involvement of angiotensin II in glomerulosclerosis of stroke-prone spontaneously hypertensive rats.

Renal plasma flow (RPF), glomerular filtration rate (GFR), glomerular pathology and glomerular TGF-beta gene expression were examined in 12- and 24-week-old stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar Kyoto rats (WKY). These parameters were also examined in SHRSP treated with equihypotensive doses of angiotensin II receptor antagonist (CV-11974:CV) and hydralazine (Hyd) for 12 weeks. Twelve-week-old SHRSP showed a decrease in RPF and GFR, and an increase in filtration fraction (FF) and urinary protein excretion (UP) compared to WKY. CV normalized these parameters, whereas although Hyd showed improved levels they were not to the levels achieved by the WKY. Glomerular TGF-beta expression was increased 2.0-fold in 12- and 24-week-old SHRSP, and CV, but not Hyd, decreased it to the control levels of WKY. At 24 weeks old, SHRSP showed a higher glomerulosclerosis index (GI) than WKY. CV, but not Hyd, lowered the GI to the level of the WKY controls. These data indicate that renal hemodynamic changes are closely associated with an increased TGF-beta expression in SHRSP and that this condition is caused by angiotensin II.

Angiotensin II↗

PubMed1996

Myocardial sympathetic dysinnervation in doxorubicin cardiomyopathy.

Single photon emission computed tomography (SPECT) using I-123 metaiodobenzylguanidine (MIBG) was evaluated for the detection of doxorubicin (DXR) cardiomyopathy in seven patients with malignant lymphoma receiving DXR doses ranging from 70 to 530 mg (DXR group), and 20 normal subjects without hypertension, diabetes mellitus or electrocardiographic abnormalities (control group). The ratio of the heart to mediastinal counts (H/M) and the washout rate (WR) in MIBG SPECT images were compared between the two groups. Correlation of total doses of DXR with H/M and the relationship of H/M to WR were investigated. The H/M of the DXR group was lower than that of the control group (3.00 +/- 0.97 vs 4.90 +/- 1.08, p < 0.001). The WR of the DXR group was higher than that of the control group (30.9 +/- 10.5% vs 16.5 +/- 9.1%, p < 0.001). Total DXR doses were inversely correlated with H/M (r = -0.86), H/M correlated inversely with the WR (r = -0.83) only in the DXR group. Pathological findings of one patient, who died of DXR cardiomyopathy, showed atrophic and fibrotic nerve fibers in the apical inferior segment of the left ventricle where MIBG uptake was reduced markedly. DXR cardiomyopathy can be detected with MIBG SPECT as cardiac sympathetic nervous dysinnervation. The pathological findings correspond to the MIBG SPECT findings.

3-Iodobenzylguanidine↗

PubMed1996

[Visiting nurse support for patients wishing to die at home].

Thirty-two (1994) and 55 (1995) patients in the terminal stage of many kinds of cancer were cared for satisfactorily at home by a visiting team of nurses from Niigata Cancer Center Hospital. A prostate cancer patient with multiple bone metastasis was suffering from morphine-resistant intractable pain, and highly dependent on medical care. We continued to take care of him by frequent visitation and psychological assist until he eventually died at home according to his wishes. It is important to create a suitable support team for the continual difficult home care of each terminal patient.

Attitude to Death↗

PubMed1995

Doc2: a novel brain protein having two repeated C2-like domains.

Two repeated C2-like domains interacting with Ca2+ and phospholipid are found in synaptotagmin and Rabphilin-3A which are implicated in neurotransmitter release. Here we have isolated a cDNA encoding a novel protein having two repeated C2-like domains from a human brain cDNA library. The isolated cDNA encodes a protein with 400 amino acids and a M(r) of 44,071. The purified recombinant protein indeed interacts with Ca2+ and phospholipid. We have named this protein Doc2 (Double C2). Doc2 is exclusively expressed in brain and is highly concentrated in the synaptic vesicle fraction. These results suggest that Doc2 is a novel brain protein and serves as a Ca2+ sensor in neurotransmitter release.

Adaptor Proteins, Signal Transducing↗

PubMed1995

Antioxidative action of the beta-adrenoceptor antagonist bopindolol and its metabolite 18-502.

The antioxidative effects of beta-adrenoceptor antagonists and related compounds were investigated. Among the beta-adrenoceptor antagonists, the agents with a potent membrane-stabilizing activity such as bopindolol and propranolol strongly inhibited the hydrogen peroxide (H2O2)-induced lipid peroxidation of liver microsomes. Fifty percent inhibition concentration values for the lipid peroxidation of bopindolol, 18-502 (metabolite of bopindolol) and propranolol were calculated to be 1.8 microM, 10 microM and 2.3 microM, respectively. The same potency order of the agents for the inhibition of lipid peroxidation was observed in rat heart homogenates. Furthermore, cytochrome P-450-catalyzing lipid peroxidation in microsomes and H2O2-induced lipid peroxidation in coronary arteries or cardiac muscles of pigs were also inhibited by bopindolol, whereas propranolol was less effective. Bopindolol and 18-502, but not propranolol, scavenged a stable free radical 1,1-diphenyl-2-picrylhydrazyl. Thus it was concluded that bopindolol that has membrane-stabilizing and radical scavenging activities is a more potent antioxidant than propranolol and may produce a beneficial effect for the treatment of ischemic cardiac diseases.

Adrenergic beta-Antagonists↗

PubMed1995

Electromyographic (EMG) study of the elbow flexors during supination and pronation of the forearm.

Activities of the elbow flexors during supination and pronation of the forearm in a normal human volunteer were studied by an electromyography (EMG). The volunteer performed the movement slowly or quickly holding elbow flexion at various angles with or without a load. The biceps brachii showed an increase and a decrease of EMG activities during supination and pronation, respectively. The brachialis and brachioradialis showed a reduction and an increment of EMG activities accompanied by an increase and a decrease of EMG activities in the biceps brachii, respectively. These findings seem to indicate that reciprocal contractions among the elbow flexors permit the biceps brachii to work for supination without an induction of elbow flexion.

Adult↗

PubMed1995

Control of thumb movements: EMG analysis of the thumb and its application to functional electrical stimulation for a paralyzed hand.

This paper describes the control of thumb movements by functional electrical stimulation (FES). In order to determine stimulation data of thumb muscles, activities of nine thumb muscles and the palmaris longus were analyzed in normal subjects by averaging their EMGs. In this analysis, it was found that well coordinated contractions of these thumb muscles were required for finer movements and precise positioning of the thumb. Based upon this analysis, several standard stimulation data for the thumb muscles were programmed and stored into a computer-controlled FES system. Input of the threshold and maximum stimulating voltages for individual thumb muscles of normal subjects to the system enabled automatic creation of stimulation data for each subject. The thumb movements of the normal subjects induced by these data were very smooth and their trajectories were reproducible. In addition, precise thumb positioning and joint stability were easily obtained. These standard stimulation data for the thumb muscles were also applied to FES control of a C4 quadriplegic. The controllability of the thumb movements was improved and the reliability of hand tasks achieved by FES was increased.

Adult↗

PubMed1994

13C NMR study on conformation and dynamics of the transmembrane alpha-helices, loops, and C-terminus of [3-13C]Ala-labeled bacteriorhodopsin.

We have recorded 13C CP-MAS and DD-MAS NMR spectra of untreated and deionized [3-13C]-Ala-labeled bacteriorhodopsin (bR) and those cleaved with carboxypeptidase A and papain to gain insight into the conformation and dynamics of the transmembrane alpha-helices, loops, and C-terminus. It turned out that the C-terminus does not contribute to the 13C CP-MAS NMR spectra of [3-13C]Ala-bR recorded at ambient temperature owing to its rapid reorientational motions, since the relative peak intensities were unchanged in spite of the enzymatic cleavages. Therefore, the 13C CP-MAS NMR peaks of bR should be ascribed both to the transmembrane alpha-helices and loops. We further distinguished the peaks of the alpha II-helix form at 16.3 ppm (60%) from those of the alpha I-helix form at 14.9 ppm (20%) by deconvolution of the respective peaks of the hydrated [3-13C]Ala-bR, as referred to the 13C chemical shift of polyalanine in hexafluoroisopropyl alcohol. The remaining CP-MAS NMR peak of [3-13C]Ala-bR at 17.2 ppm was ascribed to the loops (20%) taking a variety of turn structures. In contrast, the 13C NMR signals from the C-terminal residues were significantly enhanced by recording the dipolar-decoupled (DD)-MAS NMR spectra. Conformational features of the two different portions of the C-terminus, residues 245-248 and 231-244, were revealed by the conformation-dependent 13C signals of bR successively cleaved by carboxypeptidase A and papain, respectively. The terminal end, residues 245-248, containing two Ala residues is virtually disordered and undergoing rapid motions.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine↗

PubMed1994

A high-resolution 15N solid-state NMR study of collagen and related polypeptides. The effect of hydration on formation of interchain hydrogen bonds as the primary source of stability of the collagen-type triple helix.

High-resolution solid-state 15N-NMR was used to clarify the effect of hydration on the stability of the coiled-coil triple-helix conformation of Gly-Xaa-Yaa repeating units in collagen and the collagen-like polypeptides, (Pro-Ala-Gly)n and (Pro-Pro-Gly)10, because the stability is thought to be related to the presence of (Gly)NH ... O = C(Xaa or Pro) hydrogen bonds. The 15N-NMR signals of these samples were narrowed upon hydration, mainly due to hydration-induced conformational change or rearrangement of the repeating units. In particular, the 15N chemical shifts of the Gly N-H group and the high-field (low-frequency) shoulder peak of Pro nitrogen signals in (Pro-Pro-Gly)10 were shifted downfield (4.9 ppm and 6.8 ppm, respectively) with increasing relative humidity, while the corresponding peaks for collagen and (Pro-Ala-Gly)n were unchanged and close to the 15N shift of (Pro-Pro-Gly)10 in the hydrated state. Such downfield shifts are consistent with the formation of N-H ... O = C hydrogen bonds. In agreement with the NMR results, it was found that the (Gly)NH ... O = C (Xaa or Pro) hydrogen bonds are retained in dehydrated collagen fibrils but not in partially dehydrated (Pro-Pro-Gly)10. No evidence was obtained for the partial formation of the 3(1) helix form (Pro)n or (Gly)n either under hydrated or dehydrated conditions. It is concluded that the Gly 15N chemical shift is a very sensitive probe for studying supercoiling in collagen and collagen-like polypeptides.

Amino Acid Sequence↗

PubMed1994

The cortico-pallidal projection in the rat: an anterograde tracing study with biotinylated dextran amine.

The projections from the frontal cortex to the pallidum (e.g. the globus pallidus and the entopeduncular nucleus) were studied in the rat using the biotinylated dextran amine (BDA) anterograde tracing method. Injections of BDA into the precentral medial and precentral lateral cortices consistently yielded labeling of thin fibers with small boutons in the ipsilateral pallidum although not in the contralateral pallidum. Electron microscopic observation revealed that BDA-labeled boutons form asymmetric synapses mainly with small dendrites and dendritic spines. When the injection sites included the insular, orbital, and prelimbic cortices, the labeled fibers and boutons were also seen in the ventral pallidum, the basal nucleus of Meynert, and the substantia innominata. Injections of BDA in the parietal and occipital cortices resulted in either very few labeling or no labeled boutons in the pallidum. The cortico-pallidal projections were topographically organized. The density of labeled boutons in the globus pallidus was found to be approximately 10% of the density of cortical terminals in the neostriatum.

Animals↗

PubMed1994

The gene responsible for LEC hepatitis, located on rat chromosome 16, is the homolog to the human Wilson disease gene.

We identified the rat homolog to the human Wilson disease (WD) gene as the gene responsible for hepatitis (hts) in the Long Evans Cinnamon (LEC) rat. A genetic study using fifty-three backcross progenies showed that the rat WD gene detected by Southern blotting using the human WD gene as a probe was tightly linked to the hts phenotype of the LEC rat with no recombination. LEC is a transcriptionally deficient mutant because no transcript of the rat WD gene could be found in the LEC rat by Northern blotting. This rat WD gene was mapped to 16q12.23-12.3 by fluorescence in situ hybridization and mouse x rat somatic cell hybrid analysis.

Animals↗