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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 235 records · Page 13Linked to original sources
PubMed1997

[Sero-negative tsutsugamushi disease (scrub typhus) diagnosed by polymerase chain reaction].

We report a case of sero-negative tsutsugamushi disease diagnosed by polymerase chain reaction (PCR). A 54-year-old man who worked in Nagano prefecture presented with flu-like symptoms that did not respond to cephalosporin therapy. On admission to another hospital, chest roentgenography revealed abnormal shadows; liver dysfunction was also present. Despite therapy, the patient's condition gradually worsened and he was transferred to our intensive care unit. Erythema on all extremities and scabs on the right medial femoral region and the dorsum of the left foot suggested a diagnosis of tsutsugamushi disease. We administered minocycline and gave percutaneous cardiopulmonary support for adult respiratory distress syndrome. Despite all efforts, the patient died. Although serologic tests were not positive, Karp strains of R. tsutsugamuschi were identified on PCR amplification. Autopsy revealed evidence of acute hemorrhagic pancreatitis, which has not been reported previously in tsutsugamushi disease. We conclude that PCR techniques may be useful in confirming a diagnosis of early tsutsugamushi disease.

DNA, Bacterial↗
PubMed1996

Dual roles of sphingolipids in signaling of the escape from and onset of apoptosis in a mouse cytotoxic T-cell line, CTLL-2.

In our previous study, the sphingosine-like immunosuppressant, ISP-1, was found to suppress the proliferation of an interleukin-2-dependent cytotoxic T cell line, CTLL-2, through the inhibition of serine palmitoyltransferase, which catalyzes the committed step of sphingolipid biosynthesis. Analysis of the effect of ISP-1 by flow cytometry revealed that the ISP-1-dependent decrease in cell number was not due to inhibition of the cell cycle progression of CTLL-2 cells but to the induction of apoptosis of the cells. The ISP-1-induced apoptosis was inhibited by the addition of sphingosine (2 microM), suggesting that this ISP-1-induced apoptosis is triggered by the decrease in the intracellular levels of sphingolipids caused by the inhibition of serine palmitoyltransferase. However, another interleukin-2-dependent cell line, F7, which was derived from a mouse pro-B cell line, did not show ISP-1-dependent apoptosis, indicating that the effect of ISP-1 may be specific for a certain type of T cell lineage such as CTLL-2. On the other hand, a high dose of sphingosine (5 microM) by itself induced the apoptosis of CTLL-2 cells. This sphingosine-dependent apoptosis was also observed with F7 cells. These results provide evidence that the intracellular levels of sphingolipids play an important role in the signaling of the escape from and onset of apoptosis of CTLL-2 cells.

Acyltransferases↗
PubMed1996

Molecular cloning and characterization of the human interleukin-11 receptor alpha-chain gene, IL11RA, located on chromosome 9p13.

The human gene coding for the interleukin-11 receptor (IL11RA) was cloned and its structure analyzed. The gene is composed of 13 exons comprising nearly 10 kb of DNA that was completely sequenced. The intron-exon boundaries were determined based on the mouse Etl2 and interleukin-11 receptor cDNAs that were recently cloned. The protein sequence predicted by the human gene was over 83% identical with its murine counterpart, with very strict conservation of functionally important domains and signatures. Fluorescence in situ hybridization showed the gene to be located on human chromosome 9p13, syntenic with the mouse etl2 gene on chromosome 4. The coding exons of the Interleukin-11 gene were sequenced in a patient with the cartilage-hair hypoplasia syndrome, which has been linked to a gene on chromosome 9, but no functional mutations were detected.

Amino Acid Sequence↗
PubMed1996

Uptake of radioactive octanoate in astrocytoma cells: basic studies for application of [11C]octanoate as a PET tracer.

Fatty acids are taken up and metabolized in the brain. In vitro uptake experiments on astrocytoma cells were carried out to assess the potential use of [1-11C]octanoate as a positron emission tomography (PET) tracer for astroglial functions. Uptake of [1-14C]octanoate increased in a time-dependent fashion until 60 min after application. The uptake of [1-11C]octanoate showed similar results to that of [1-14C]octanoate until 10 min. As for medium pH, [1-14C]octanoate uptake increased gradually with the decrease in pH. We also examined the effects of glutamate, glucose deprivation and hypoxia on the uptake of octanoate and found that these conditions did not bring about any change in the extent of [1-14C]octanoate uptake. These results show that the octanoate uptake was not influenced by any of several pathological conditions. When the number of astrocytes increases in the area of hypoglycemia or hypoxia near a brain lesion, the amount of octanoate uptake also increases, so this indicates the possibility that 11C-octanoate will detect a brain lesion.

Astrocytoma↗
PubMed1996

Occult macular dystrophy.

PURPOSE: Occult macular dystrophy is a hereditary macular dystrophy without any visible abnormality of the fundus or abnormality indicated by fluorescein angiography even when visual acuity is decreased. Normal full-field electroretinogram in both cone and rod components with abnormal focal macular cone electroretinogram is the key to diagnosing this disorder. The purpose of this study was to identify the function of the macular rods and to provide detailed clinical findings in occult macular dystrophy. METHODS: Thirteen patients from eight families were examined. The fundi of 12 patients were essentially normal (occult macular dystrophy), and the oldest patient in one family disclosed bull's eye maculopathy. In the 12 patients, including the patient with bull's eye maculopathy, the profiles of cone and rod absolute thresholds were performed across the 60-degree horizontal meridian of the posterior pole. RESULTS: All 12 patients showed cone sensitivity loss only in the macular area. Six relatively young patients revealed normal rod sensitivity, whereas six older patients showed borderline rod sensitivity or abnormal rod sensitivity in the macular area. CONCLUSIONS: The pathology of occult dystrophy involves either only the macular cone system or macular cone and rod systems without any visible abnormality. This difference of the pathology suggests a different clinical entity or a different stage of occult macular dystrophy.

Adolescent↗
PubMed1996

[1-11C]octanoate as a potential PET tracer for studying glial functions: PET evaluation in rats and cats.

To evaluate the ability of [1-11C]octanoate as a PET tracer for imaging the brain, we examined its distribution in the brain and surrounding tissues in rats and cats with PET. In rats, owing to the accumulated radioactivity in the harderian glands, clear brain images were not obtained at rostral levels. In cats, the brain was imaged clearly at every level of the coronal brain slices, suggesting the potential of [1-11C]octanoate for imaging the brain.

Animals↗
PubMed1996

A compound heterozygote for familial hypercholesterolaemia with a homozygous mother.

Homozygous familial hypercholesterolaemia (FH) is a rare disorder in which the patients develop severe hypercholesterolaemia and premature coronary atherosclerosis from childhood. Here we report a unique family with clustering of homozygous FH. The proband was a 25-year-old man, who showed marked hypercholesterolaemia, multiple xanthomas and severe coronary atherosclerosis. His mother also showed the typical characteristics of homozygous FH. Sequencing analysis of the low-density lipoprotein receptor gene revealed that he was a compound heterozygote, carrying two different point mutations. One was a novel mutation, FH Wakayama (Cys-->Ser at 317), derived from his mother, and the other was a recurrent mutation, FH Niigata (T-->C at 1845 + 2, 5' splice signal in intron 12), derived from his father. The proband we report seems to be a very rare case of an FH homozygote born from a homozygous mother.

Adult↗
PubMed1996

Reduction of 123I-iomazenil uptake in haemodynamically and metabolically impaired brain areas in patients with cerebrovascular disease.

Iomazenil is a specific ligand for central-type benzodiazepine receptors (BZR). In order to determine the clinical significance of the findings of 123I-iomazenil single photon emission tomography (SPET) in cerebrovascular disease (CVD), we compared the cerebral uptake of 123I-iomazenil with oxygen metabolism measured by positron emission tomography (PET). Depending on the severity of the haemodynamic and/or metabolic impairment based on our institutional criteria [a reduction of < 30.6 ml 100g-1 min-1 in cerebral blood flow (CBF) and an increase of > 0.52 in the oxygen extraction fraction (OEF)], the cortical areas were classified into four groups as follows: Group I, normal CBF and OEF; Group II, normal CBF and increased OEF; Group III, reduced CBF and normal OEF; Group IV, reduced CBF and increased OEF. Seven patients (mean age 65 +/- 7 years) with CVD underwent both PET and 123I-iomazenil SPET within 8 days. The ratios of the mean counts in 14 regions of interest in the cerebral cortices to those in the cerebellar cortices (R/C ratios) were compared with the cerebral metabolic rate of oxygen (CMRO2). The R/C ratios of Group IV were lower than those of Group I (P < 0.005). The R/C ratios correlated with CMRO2 in Group III (r = 0.577, P < 0.01) and in Group IV (r = 0.707, P < 0.005), but not in Groups I or II. These results suggests that reduced uptake in 123I-iomazenil SPET reflects oxidative hypometabolism causing neuronal damage in haemodynamically and metabolically impaired areas in patients with CVD. This information may be valuable when deciding therapeutic approaches.

Aged↗
PubMed1996

Vasoreactive effect of acetazolamide as a function of time with sequential PET 15O-water measurement.

The accurate assessment of vascular flow reserve is crucial for the evaluation of risk among patients with cerebrovascular disease. In six patients with unilateral occlusion of the internal carotid artery and one patient with unilateral occlusion of the middle cerebral artery (mean +/- S.D. age = 68 +/- 3 years), we measured cerebral blood flow (CBF) after the administration of 940 MBq 15O-water using a remotely controlled power injector. Studies were performed at rest, after 10 min, and then 10, 20 and 30 min after the administration of 1 mg acetazolamide to evaluate the vasoreactive effect, as reflected by an increase in CBF. Sixteen regions of interest (ROIs) were drawn over the CBF images. These ROIs were as follows in each hemisphere: Area I, four areas in the cortical middle cerebral arterial territory (superior frontal, frontal, temporal and parietal areas); Area II, four areas of the deep middle cerebral and vertebral arterial territory (occipital area, basal ganglia, thalamus and cerebellum). Taking normalized resting CBF to be 100%, the mean CBF measured 10, 20 and 30 min post-injection using sequential positron emission tomography was as follows: Area I, 141.4 +/- 16.3, 127.7 +/- 15.3 and 128.2 +/- 17.4% for non-occluded sites and 116.3 +/- 22.8, 112.7 +/- 16.4 and 114.9 +/- 17.1% for occluded sites; Area II, 143.4 +/- 14.5, 126.2 +/- 10.4 and 125.0 +/- 12.9% for non-occluded sites and 141.9 +/- 28.9, 126.0 +/- 20.5 and 124.1 +/- 17.1% for occluded sites. A significant difference in mean CBF was noted between the non-occluded and occluded sites in Area I, the most marked difference of 25.1% being observed 10 min after the administration of the acetazolamide. We conclude that for an accurate assessment of vascular reserve in patients with cerebrovascular disease, CBF should be measured 10 min post-administration of the acetazolamide.

Acetazolamide↗
PubMed1996

Isolation and characterization of teichoic acid-lake substance as an adhesin of Staphylococcus aureus to HeLa cells.

A cell wall component that bound to HeLa cells (HeLa cell-binding CWC) was isolated from a clinical isolate of Staphylococcus aureus. The HeLa cell-binding CWC was resistant to heat (100 C, 1 hr) and proteases, did not stain with Coomassie Brilliant Blue R-250 on SDS-PAGE but stained as a broad band with antiserum against the strain on Western blots. These data suggest that the HeLa cell-binding CWC is not a protein, and may be teichoic acid. Purified teichoic acid bound to HeLa cells, whereas fractions without teichoic acid did not. In Western blots, HeLa cell-binding CWC appeared as a broad band of less than 35 kDa, similar to that of purified teichoic acid. These data suggest that the HeLa cell-binding CWC obtained in this study is teichoic acid. Teichoic acid inhibited S. aureus adherence to HeLa cells and bound to the cells time and dose dependently, in a saturable and reversible manner, and therefore appears to be an adhesin of S. aureus to HeLa cells.

Adhesins, Bacterial↗
PubMed1996

Distribution of human herpesvirus 6 and varicella-zoster virus in organs of a fatal case with exanthem subitum and varicella.

The distribution of human herpesvirus 6 (HHV-6) and varicella-zoster virus (VZV) was examined in autopsy samples from a fatal case with both virus infections. A 9-month-old boy developed convulsive seizures followed by macular skin rashes, rapidly progressed to brain death, and died 15 days after the onset, when signs of varicella were noted. An isolation of HHV-6 from blood and evaluation of antibody activities to various viral agents including HHV-6 were performed before his death. Postmortem examinations included: (i) isolation of HHV-6 and VZV from tissues or organs; (ii) detection of both virus antigens in tissues or organs by an indirect immunofluorescent assay using monoclonal antibodies to both viruses; (iii) amplification of both viruses and human herpesvirus 7 DNA sequences by a nested polymerase chain reaction assay; and (iv) endonuclease digestion of amplified products of HHV-6 DNA for differentation of variants A and B. Human herpesvirus 6 DNA was detected in peripheral blood mononuclear cells (PBMC) and plasma obtained at the eruptive stage but present only in PBMC 15 days after, indicating the primary infection with HHV-6, although the virus was not isolated from the same blood sample and a significant rise in the antibody titers to HHV-6 was not observed. Both virus antigens and DNA were detected in various tissues or organs obtained at autopsy, but only VZV was isolated from these samples, suggesting disseminated infection with both viruses in an infant. All the amplified products of HHV-6 DNA were variant B. Among the findings for the distribution of virus antigens, it was noteworthy that HHV-6 antigen was demonstrated in the endothelial cells of small vessels in the frontal lobe of the brain. There was no evidence of HHV-7 infection. These data indicate that the primary HHV-6 infection closely followed by the primary VZV infection had the potential hazard of an unexpected and apparently life-threatening event, in which disseminated infections with both viruses were noted in multiple tissues or organs including the brain.

Antibodies, Viral↗
PubMed1996

Post-traumatic symptoms among younger and elderly evacuees in the early stages following the 1995 Hanshin-Awaji earthquake in Japan.

We assessed the frequency of short-term, post-traumatic symptoms among evacuees of the Hanshin-Awaji earthquake. A total of 67 younger subjects (under 60 years) and 75 elderly subjects (60 years or above) were interviewed during the third week after the earthquake, and 50 and 73 subjects, respectively, were interviewed during the eighth week. All subjects were assessed using the Post-Traumatic Symptom Scale. During the first assessment, subjects from both age groups experienced sleep disturbances, depression, hypersensitivity and irritability. During the second assessment, the percentage of younger subjects experiencing symptoms did not decrease, while elderly subjects showed a significant decrease in 8 of 10 symptoms. This may have been due to such factors as decreased psychological stress, extensive social networks, and previous disaster experiences in the case of the elderly subjects.

Adolescent↗
PubMed1996

The use of epoxy patch grafts for the repair of experimentally-created diaphragmatic defects in dogs.

Canine pericardium which had been treated with polyepoxy compounds (Denacol EX-313) was used as a patch graft for the correction of experimentally-created diaphragmatic defects in five dogs belonging to the same litter. Clinical, macroscopic and histological examinations were conducted every month up to five months after suturing of the patch graft. Clinical examination of the patch graft showed no apparent abnormalities. Macroscopic examination conducted during autopsy showed that the patch graft maintained adequate elasticity for five months after suturing, the surface of the patch graft was covered with a thin membrane and neovascularization was observed. Histological examination showed that the surface of the patch graft was covered with a thin membrane. Inflammatory tissue reactions were observed at one month, but gradually decreased from the second month onwards. In addition, the patch graft had excellent tissue affinity.

Animals↗
PubMed1996

A comparison of amino acid sequences of hepatitis B virus S gene in 46 children presenting various clinical features for immunoprophylaxis.

We compared amino acid sequences of hepatitis B virus (HBV) S protein deduced from analyzed DNA sequence in 46 children who received immunoprophylaxis to prevent mother-to-child transmission of HBV. They were classified into 6 groups by their clinical features. The antibody escape mutants were found in 8 cases among 46 cases. We studied the difference in clinical features in these cases and speculated that 126 Ser or 140 Ser-strain may have a different behavior in relation to antibody to hepatitis B surface antigen from 126 Asn or 145 Arg-strain.

Amino Acid Sequence↗
PubMed1996

S-cone pathway sensitivity in diabetes measured with threshold versus intensity curves on flashed backgrounds.

PURPOSE: To study sensitivity loss to short wavelength lights in patients with diabetes with or without retinopathy and to identify changes that cannot be attributed to preretinal screening. METHODS: Flash-on-flash thresholds were measured in 41 patients with diabetes and were compared to those in age-matched normals. A 50-ms, 1 degree blue test spot was presented simultaneously with a 500-ms, 2 degree blue flash. A bright yellow background isolated the S-cone system. RESULTS: The mean flash-on-flash threshold curve shifted up as the stage of retinopathy progressed in 16 patients with insulin-dependent diabetes mellitus (IDDM), including those without retinopathy. In 25 patients with noninsulin-dependent diabetes mellitus (NIDDM), those with preproliferative retinopathy revealed sensitivity loss; however, those with background retinopathy or without retinopathy showed no statistically significant change in sensitivity. CONCLUSIONS: The pattern of sensitivity loss in the patients with IDDM cannot be caused by changes in preretinal screening, including yellowing of the lens. Further, early functional changes in the patients with IDDM without retinopathy can be detected by this method.

Adolescent↗
PubMed1996

Increased serum concentrations of pro-gastrin-releasing peptide in patients with renal dysfunction.

BACKGROUND: Gastrin-releasing peptide has a prominent role as a tumour marker in the diagnosis of small-cell lung carcinoma. This study was designed to assess the validity of a newly developed enzyme-linked immunosorbent assay (ELISA) for pro-gastrin-releasing peptide in patients with renal and systemic diseases. METHODS: Pro-gastrin-releasing peptide concentrations in sera from normal subjects and patients with small-cell lung carcinoma, diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus, chronic glomerulonephritis, or undialysed or dialysed chronic renal failure were measured with the TND-4 Kit, a newly developed ELISA for pro-gastrin-releasing peptide. RESULTS: All of the patients with normal renal function, whether they had diabetes mellitus (n=16), rheumatoid arthritis (n=10), systemic lupus erythematosus (n=12) or chronic glomerulonephritis (n=14), had serum pro-gastrin-releasing peptide concentrations less than 46 ng/l, the upper limit in normal subjects. In contrast, 14 or 16 patients (88%) with small-cell lung carcinoma, who had normal renal function, and 25 of 26 (96%) patients with chronic renal failure on haemodialysis had serum pro-gastrin-releasing peptide concentrations greater than 46 ng/l. The highest serum pro-gastrin-releasing peptide levels in patients with chronic renal failure, before and after initiating haemodialysis were 183 and 290 ng/l respectively. Ten of 16 (63%) small-cell lung carcinoma patients had serum pro-gastrin-releasing peptide concentrations greater than 290 ng/l, the highest level in haemodialysed patients. Serum pro-gastrin-releasing peptide concentrations were also elevated in patients with chronic glomerulonephritis or diabetes mellitus when their serum creatinine concentrations were greater than 120 micromol/l. And, there was a significant correlation, y=23.5+0.15x(n=22, r=0.82, P<0.001),between serum pro-gastrin-releasing peptide (y, in ng/l) and serum creatine (x in micromol/l) concentrations in those patients with renal dysfunction. The correlation between serum pro-gastrin-releasing peptide and serum urea nitrogen concentrations was likewise significant. CONCLUSIONS: The evaluation of patients as to their renal functional state may be mandatory when serum pro-gastrin-releasing peptide levels are to be applied as one of the diagnostic tools for small-cell lung carcinoma or as a marker monitoring their clinical course.

Adult↗
PubMed1996

[Foveal cone densitometry in high myopia].

We performed foveal cone densitometry using a modified fundus camera in 17 eyes of 17 normal subjects (age range, 20 to 47 yr, refractive error, +2.0 to -2.5 D) and 15 eyes of 15 high myopia subjects with normal visual acuity (age range, 18 to 46 yr, refractive error, -9.0 to -14.5 D). After fully bleaching, the density of photopigment was measured for 7 minutes by a test spot of 562 nm in wavelength and 1 degree in diameter, focussed on the fovea. Two-way density and the time constant of pigment regeneration were calculated. No significant difference was found in two-way density between the two groups. The time constant in high myopia (161.6 +/- 36.6 sec), however, was significantly increased (p < 0.01), compared with normals (124.0 +/- 28.7 sec). To study the correlation of psychophysical visual function, we performed a photostress recovery test, which revealed a significant delay of the recovery time in high myopia (p < 0.01). These results suggest that a delay in foveal cone pigment kinetics precedes loss of cone cells or chorioretinal degeneration in high myopia.

Adolescent↗