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Biomedical subjects

K Kano

Publications and source records attributed to K Kano.

At least 19 recordsLinked to original sources
PubMed1992

Tetraparental mice reveal complex cellular interactions of the mutant, autoimmunity-inducing lpr gene.

Lpr is a murine recessive autosomal mutant gene that, in conjunction with the background genes of different inbred mouse strains, produces varied syndromes of lymphadenopathy and autoantibody production. We have investigated the cellular basis of the lpr determined phenomena by constructing allophenic (tetraparental) chimeras of MRL/Mp-lpr/lpr combined with C57BL/6 and MRL/+ combined with C57BL/6-lpr/lpr. The appearance of lymphadenopathy, lpr atypical T cells, and autoantibodies was found to depend on the relative amounts +/+ and lpr tissue. The failure of these three abnormalities to correlate in certain animals suggested different pathways of lpr gene action. Furthermore, in the lpr predominant animals, both the lymphadenopathy and autoantibodies were essentially entirely contributed by the lpr donor. The expression of the lpr gene within the same cells expressing the MRL or B6 background determined the pathologic and serologic manifestations characteristic of the disease of that lpr strain, despite the presence of +/+ cells of the other background in the same individual. The lpr syndrome thus depends on the intracellular interaction of the lpr and background genes, and on positive signalling between different lpr cell populations.

Animals↗
PubMed1992

The topographical features of EEGs in patients with affective disorders.

EEG data were obtained in the basic state from 16 scalp sites of 44 patients with affective disorder, diagnosed by DSM-III criteria, and 44 normal controls. The EEG power spectra were computed and the t statistic significance probability mapping (SPM) was applied to visualize regions where the patient group showed differences in the EEG topogram from the controls. The results show: (1) left occipital predominance (P3, O1) of alpha activities in the patients with affective disorders, (2) decreased alpha activities in Fp2 and F8 areas in patients with major depression without melancholia, (3) decreased alpha activities in F7 area in patients with bipolar disorder, manic, and (4) increased beta 2 activity in F4 and C4 areas in patients with major depression with melancholia. These results suggest that inter-hemispheric and intra-hemispheric relationships may be disturbed in patients with affective disorder.

Adult↗
PubMed1992

Conservation of genes encoding HLA-B5 and B35 cross-reactive group antigens in various races.

HLA-B5 and B35 CREG antigens include HLA-B35, B51, B52, B53, and B78. Recent studies suggest that the genes encoding the HLA-B5, B35 CREG, and HLA-B58 antigens share a common ancestor. We sequenced the exons of the genes encoding HLA-B51, B53, and B58 from American black individuals and the gene HLA-B52 encoding from an Arabic individual, and compared them with previously reported sequences of HLA-B51 (B*5101) and HLA-B52 (B*5201) from Japanese, HLA-B53 (B*5301) from an Algerian, and HLA-B58 (B*5801) from a Sardinian. The sequences of the genes from the American black and Arabic individuals were identical to those from the other races. These findings support the hypothesis that these antigens have evolved prior to divergence of the major ethnic groups.

Base Sequence↗
PubMed1992

Effect of the substitutions in the alpha helix and the beta sheet of HLA class I molecule on allorecognition of T cells specific for HLA-B51 and HLA-Bw53.

HLA-B51 and HLA-Bw53 differ by eight amino acids on the alpha 2 domain. Of these eight amino acid substitutions, two are in the alpha helix and six are in the beta sheet. The effect of these substitutions on allorecognition of HLA-B51-specific cytotoxic T lymphocyte (CTL) clones and HLA-Bw53-specific CTL clones was investigated using chimeric antigen (Ag) between HLA-B51 and HLA-Bw53. Of 12 HLA-B51-specific CTL clones, recognition of one clone was abolished by the substitutions on the beta sheet alone, that of two clones by the substitutions on the alpha helix alone, and that of nine clones not only by the substitutions on the alpha helix but also by those on the beta sheets. On the other hand, of 17 HLA-Bw53-specific CTL clones, recognition of 10 clones was affected by the substitutions on the alpha helix alone and that of 7 clones not only by the substitutions on the alpha helix but also by those on the beta sheet. The present study demonstrated that the substitutions (residues 152 and 171) on the alpha helix critically affect recognition of HLA-B51-specific CTL clones and HLA-Bw53-specific CTL clones and that the substitutions on the beta sheet affect also recognition of the majority of HLA-B51-specific CTL clones and 40% of HLA-Bw53-specific CTL clones. These results indicate that the substitutions at the floor of the peptide binding groove affect recognition of allogeneic CTL.

Amino Acid Sequence↗
PubMed1992

Effect of Harderian gland-derived growth factor on the growth of cornea stromal cells.

To investigate the physiological role of Harderian gland-derived growth factor (HGDGF), the effects of HGDGF and various other growth factors on the growth of cultured guinea pig cornea stromal cells were examined. HGDGF increased the incorporation of [3H]thymidine to 150% of the control (5% fetal calf serum). The combination of HGDGF with fibroblast growth factors (FGFs) or platelet-derived growth factor enhanced the cell growth over that of either growth factor alone, increasing the incorporation of [3H]thymidine to 180 and 190% of the control, respectively. The combination of HGDGF with transforming growth factor (TGF-beta) decreased the growth to 60% of the control, and epidermal growth factor had no effect on the activity of HGDGF. The growth-stimulating activity of HGDGF was inhibited by suramin in a different manner from that of FGFs. These findings suggest that HGDGF binds a specific cell-surface receptor and plays a role in the repair of injured parts of the cornea and in the maintenance of the cornea stromal cells.

Animals↗
PubMed1992

Chromosomal structure of the halophilic archaebacterium Halobacterium salinarium.

The chromosomal structure of the extremely halophilic archaebacterium Halobacterium salinarium was examined. Sheared chromosomes prepared from the bacteria in the late exponential phase were separated into two peaks (peaks I and II) by sucrose gradient centrifugation, suggesting that the chromosomes consist of two parts differing in quality. The UV spectra of peaks I and II resembled those of DNA and eukaryotic chromatin, respectively. Electron microscopic observations revealed that the major component of peak I was protein-free DNA, while the major components of peak II were rugged thick fibers with a diameter of 17 to 20 nm. The rugged fibers basically consisted of bacterial nucleosome-like structures composed of DNA and protein, as demonstrated in experiments with proteinase and nuclease digestion. Whole-mount electron microscopic observations of the chromosomes directly spread onto a water surface revealed a configuration in which the above-described regions were localized on a continuous DNA fiber. From these results it is concluded that the H. salinarium chromosome is composed of regions of protein-free DNA and DNA associated with nucleosome-like structures. Peaks I and II were predominant in the early exponential phase and stationary phase, respectively; therefore, the transition of the chromosome structure between non-protein-associated and protein-associated forms seems to be related to the bacterial growth phase.

Animals↗
PubMed1992

Increase in venous outflow from the corpora cavernosa during mild erection in dogs.

The venous outlet of the corpus cavernosum is generally believed to be obstructed during erection. Some researchers, however, have demonstrated an increased venous outflow during erection. To elucidate this discrepancy, we carried out a pressure-flow study using a perfusion model of the penile deep artery in dogs. Various states of the corpus cavernosum, which were different in cavernous pressure, were induced by a delicate control of electrostimulation to the cavernous nerve. Inflow rate into the corpus cavernosum, inflow resistance and outflow resistance were simultaneously evaluated. The inflow rate in mild erection was higher than in the flaccid state, and the outflow rate was estimated to be also higher than in the flaccid state. A probable reason for the increased outflow rate was that the arterial resistance decreased remarkably, while the venous resistance only slightly increased. In full erection, both the inflow and outflow rates were lower than in the flaccid state because of a great venous resistance. Histological observation of the canine penis indicated that compression of draining veins passing through the tunica albuginea was weak in mild erection, while intense in full erection. It was proposed that in mild erection, the effect of venous occlusion was slight though that of arterial dilation was noticeable, resulting in an increase in the venous outflow.

Animals↗
PubMed1992

Left ventricular performance at rest and during exercise in patients with dual-chamber pacemakers.

In 13 patients with an implanted dual-chamber atrioventricular (AV) demand pacemaker, left ventricular performance was elicited by pacing mode manipulation for study using gated cardiac pool scintigraphy at rest and during exercise. There was no significant difference between DDD and VVI at 70 and 90 beats/min with respect to cardiac output, peak ejection rate or peak filling rate. At 110 beats/min, the cardiac output was greater with DDD as compared to VVI. The peak filling rate was also significantly greater with DDD as compared to VVI (DDD: 3.6 vs VVI: 2.8 EDV/s, p less than 0.05). During exercise the cardiac output was greater with DDD as compared to VVI at the same rate. The peak filling rate during exercise was significantly greater with DDD as compared to VVI (DDD: 3.0 vs VVI: 2.5 EDV/s, p less than 0.01). We conclude that DDD is more beneficial than VVI in maintaining cardiac performance during exercise.

Adult↗
PubMed1992

[A study of falls experienced by institutionalized elderly].

This study was conducted to determine what factors are related to falls, conditions contributing to falls and the associated injuries. Subjects who had lived in 3 institutions for the elderly in the western region of Shizuoka Prefecture were chosen. Subjects (n = 181) had an average age of 76.4 +/- 7.8 years, and all were interviewed regardless of their history of falls. For those who had experienced falls further interviews were conducted. The following results were obtained: 1) There were 64 subjects (35.4% of the subjects) who had experienced falls, some having experienced multiple falls (for a total count of 89 falls). 2) The frequency of falls of differed by sex or age was significantly. The frequency of females was significantly higher than that of males. The frequency for those in their 70's was lower than in other age groups. 3) At the time of experiencing falls the majority of subjects had hypertension, eye symptoms, insomnia, paralysis, functional restrictions, were going up or down stairs, working, and had difficulty reading characters in newspapers, had experiences of stumbling or need of medical attention within for the past 2 years. Results of this study showed that, while the use of tranquilizers or hypnotics were not statistically significant, they were closely connected to and increase in falls among the aged. 4) In the causes of falls, intrinsic factors figured in 34 (34.0%) cases, and the extrinsic factors in 66 (66.0%). 5) Both falls and fall-caused external injuries were higher among females than males. Furthermore, female subjects mainly suffered contusions and fractures while male subjects mainly suffered abrasions.

Accidental Falls↗
PubMed1992

[Surgical treatment of double aortic arch: report of a case associated with frequent respiratory infections].

A seven-month-old baby with double aortic arch was reported. He was admitted to our hospital with complaint of frequent respiratory infections shortly after birth. On examination, bronchofiberscopy revealed compression of the trachea and left main bronchus from behind and angiography showed complete vascular ring, namely double aortic arch with no other cardiac anomaly. Soon after the operation, stridor disappeared at rest, but mild stridor persisted on exertion. Three months later, he was re-admitted to our hospital because of pneumonia. Therefore, close observation is required for the patients with double aortic arch, even if the operation is effective.

Aorta, Thoracic↗
PubMed1992

[A comprehensive fact finding study of home care elderly for planning of the community based rehabilitation system in Koga City, Ibaraki Prefecture].

An interview survey was held with the purpose of grasping the problems faced by the home care elderly living in Koga city in Ibaraki prefecture. The subjects of the study were 100 cases who had been registered as elderly requiring home care in the municipality. The main results were as follows: (1) The most frequent underlying disorders that were considered as causes of disabilities in the home care elderly were cerebrovascular diseases, senile dementia and external injuries. In 67 percent of the subjects, one of these three disorders had caused the disabilities. (2) Disabilities in self care activities and in mobility were closely related to each other and the order of the difficulty in performing these activities was similar in many cases. A large number of the subjects sustaining severe disabilities expressed discontent with their daily life. (3) Forty two percent of the subjects were so-called bedridden elderly who got out of bed for less than 3 hours a day. The Barthel index score was 60 or less in all of the bedridden subjects. (4) For most of the bedridden elderly, bed rest was not required and probably exacerbated the disuse syndrome. In order to ameliorate their condition, adequate rehabilitation programs and assistance in their daily activities need to be offered. (5) Seventy eight percent of the care givers complained about the burden of care. Those who had no assistant care giver complained more frequently. Many of the care givers complaining about their burden had their own health problems. (6) The utilization of social welfare services were not always without any problems. The number of the experts who can deal with the psychosocial aspects in the elderly should be increased in order to improve the situation.

Aged↗
PubMed1992

Increased alpha-hydroxybutyrate dehydrogenase in serum from children with measles.

For treatment and prognostic evaluation of patients with measles, it is important to determine the source of the increase in serum alpha-hydroxybutyrate dehydrogenase (HBD; EC 1.1.99.6). Here we measured HBD and L-lactate dehydrogenase (LD; 1.1.1.27) activities in the serum of 18 children with measles and in 18 age-matched control patients with bronchopneumonia. HBD and LD activities in the measles patients were significantly higher than those in control subjects (P less than 0.001). The HBD/LD ratio in the measles patients two to three days after the onset of rash was significantly lower than that in control subjects (P less than 0.001). The low HBD/LD ratio was similar to the ratio found in lymphocytes. The number of peripheral lymphocytes decreased markedly after the onset of rash. Our results suggest that increased serum HBD and LD activity is common in measles infection and that the increase originates from the destruction of infected lymphocytes rather than from myocardiac injury.

Child, Preschool↗
PubMed1991

Effects of cholestanol feeding on corneal dystrophy in mice.

A cholestanol-enriched diet administered for 8 months to BALB/c mice produced in 20% two kinds of corneal opacities resembling calcific band keratopathy and Schnyder's crystalline dystrophy in humans. The concentrations of cholestanol in serum, liver and cornea of the corneal opacity bearing mice were 30-40-times higher than those of normal mice. On the other hand, brain cholestanol level increased only 7-times in the opacity group as compared with that of control group. There was no significant difference in the cholesterol concentrations of serum and several tissues among opacity, non-opacity and the control group. The crystal particles were observed between epithelial basement membrane and superficial stroma by the electron microscopy. Energy dispersive analysis of the particles revealed that the deposits were composed principally of calcium and phosphorus with other crystalline materials, which was presumed to be cholestanol. These results suggest that the cholestanol may deposit in the cornea from elevated serum levels. Deposition of cholestanol in cornea and related area may be a cause of corneal dystrophy in CTX.

Animals↗
PubMed1991

[SPECT images after intravenous injection of 99mTc-DTPA in lung tumors--comparison with delayed 123I-IMP lung scintigraphy].

The aim of this study was to assess the efficacy of SPECT imaging of the thorax with 99mTc-DTPA, which accumulates at sites of increased capillary permeability and expanded extracellular space, by comparing it with delayed 123I-IMP lung scintigraphy. We have previously reported that increased uptake on delayed 123I-IMP lung scintigraphy was associated with atelectasis and inflammation. Thirteen patients with lung cancer (4 with atelectasis and 3 with pleurisy), one patient with malignant lymphoma complicated by pneumonia and pleurisy, and one patient with pneumonia were studied. 99mTc-DTPA scintigraphy was performed twice, 20-160 minutes and 2-4 hours after the intravenous administration of 370 MBq of 99mTc-DTPA. 123I-IMP scintigraphy was performed 24 hours after the intravenous injection of 111 MBq of 123I-IMP. SPECT images were obtained with both types of scintigraphy. 99mTc-DTPA scintigraphy was compared with 123I-IMP scintigraphy for its ability to detect atelectasis and pneumonia. All patients showed increased accumulation corresponding to the lesions on both 123I-IMP and 99mTc-DTPA scintigraphy. 123I-IMP scintigraphy showed a defect corresponding to the tumor with increased accumulation around the tumor, whereas 99mTc-DTPA scintigraphy showed accumulation corresponding to the tumor. Ten of 11 tumors showed accumulation of an intensity equal to that of the soft tissue of the chest wall on 20-60 min 99mTc-DTPA images. The 2-4 hr images showed that 99mTc-DTPA leaked from the periphery of the tumor toward its center. All the patients with pleurisy showed increased accumulation in effusion on 2-4 hr 99mTc-DTPA scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Full assignment of heme redox potentials of cytochrome c3 of D. vulgaris Miyazaki F by 1H-NMR.

Site-specific heme assignment of the 1H-NMR spectrum of cytochrome c3 of D. vulgaris Miyazaki F, a tetraheme protein, was established. The major reduction of the heme turned out to take place in the order of hemes I, III, IV and II (numbering in the crystal structure). The hemes with the smallest and greatest solvent accessibility were reduced at the highest and lowest potentials on average, respectively. A cooperative interheme interaction was attributed to a pair of the closest hemes, namely, hemes III and IV. This assignment can provide the physiochemical basis for the elucidation of electron transfer of this protein.

Cytochrome c Group↗
PubMed1991

1H NMR studies on ferricytochrome c3 from Desulfovibrio vulgaris Miyazaki F and its interaction with ferredoxin I.

The 1H NMR signals of the heme methyl, propionate and related chemical groups of cytochrome c3 from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were site-specifically assigned by means of 1D NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by Fan et al. (Biochemistry, 29 (1990) 2257-2263). The site-specific heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val18. All the results contradicted the heme assignments for D.v. MF cytochrome c3 made on the basis of electron spin resonance (Gayda et al. (1987) FEBS Lett., 217 57-61). Based on these assignments, the interaction of cytochrome c3 with D.v. MF ferredoxin I was investigated by NMR. The major interaction site of cytochrome c3 was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochrome c3 molecules per monomer of ferredoxin I and 10(8) M-2 (at 53 mM ionic strength and 25 degrees C), respectively.

Binding Sites↗
PubMed1991

T cell can recognize the allospecificities formed by the substitution of amino acids associated with HLA-Bw4/Bw6 public epitopes.

Our previous studies clearly showed that HLA-B35 and HLA-Bw53 differed only by the amino acids associated with HLA-Bw4/Bw6 epitopes, in that the former possessed Bw6 and the latter Bw4 epitope. It remains to be known whether T cell can discriminate HLA-B35 from HLA-Bw53, although the difference between these HLA antigens is discriminated by monospecific human alloantisera. To investigate allorecognition of these HLA antigens by T cells, anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 bulk CTLs from an individual with HLA-B35 clearly discriminated HLA-Bw53 from HLA-B35. On the other hand, anti-HLA-Bw53 bulk CTLs from an individual without HLA-B35 revealed weak cross-reactivity with HLA-B35 and HLA-B51. The additional studies using HLA-Bw53 or HLA-B35-specific CTL clones showed that some but not all of the CTL clones definitively distinguish the difference between HLA-Bw53 and HLA-B35. Thus, the allospecificities formed by HLA-Bw4/Bw6 epitopes were discriminated by allogeneic T cells. The present study demonstrated that HLA-Bw4/Bw6 public epitopes play an important role in allorecognition of T cells.

Amino Acid Sequence↗