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Biomedical subjects

Y Kuroda

Publications and source records attributed to Y Kuroda.

At least 703 records · Page 39Linked to original sources
PubMed1991

Treatment of HTLV-I-associated myelopathy with high-dose intravenous gammaglobulin.

Fourteen patients with HTLV-1-associated myelopathy were treated with high-dose intravenous gammaglobulin (IVGG). Ten received 10 g/day of IVGG and 4 received 400 mg/kg of body-weight/day of IVGG for 5 consecutive days. Improvement of spastic paraparesis was observed in 10 within 7 days of the commencement of IVGG. The therapeutic effects were sustained for more than 3 weeks in some patients. There were no side effects. Analysis of factors of relevance to the clinical improvement with IVGG showed that the beneficial response was preferentially found in patients having a high CSF titre of anti-HTLV-I antibodies, a high CSF IgG level and a marked brain MRI abnormality.

Adult↗
PubMed1991

Radioimmunoassay for the determination of glycated haemoglobin.

A competitive radioimmunoassay for the quantitative determination of glycated haemoglobin was developed. The antiserum, obtained by immunizing guinea pigs with reduced glycated human albumin, was capable of identifying and quantitating the glucitollysine residues of glycated Hb after reduction with sodium borohydride. To simplify the sample preparation we introduced trichloroacetic acid precipitation to remove unreacted sodium borohydride instead of using dialysis or gel filtration. Using this procedure, our radioimmunoassay became relatively simple and provided satisfactory within- and between-run (1.3-2.8% and 1.9-5.4% coefficient of variation, respectively). The radioimmunoassay method was compared to the measurement of HbAlc by high performance liquid chromatography which is the most widely used method for quantitating glycated Hb. For this purpose glycated Hb was measured in normal glucose tolerance, impaired glucose tolerance, and diabetes mellitus groups based on WHO criteria. Both assays were able to discriminate between the normal and diabetic groups. In addition, while the determination of glycated Hb by the radioimmunoassay method was able to clearly discriminate between the normal and impaired glucose tolerance groups, the determination of HbAlc by the high performance liquid chromatography method failed to discriminate between these two groups. Moreover, 15 of the 20 impaired glucose tolerance patients exceeded the upper normal range (mean normal values + 2 SD) in radioimmunoassay. But all 20 patients with impaired glucose tolerance were within the upper normal range in HbAlc values. These results demonstrate that the measurement of glycated Hb by radioimmunoassay is more sensitive than the measurement of HbAlc by high performance liquid chromatography since it can discriminate between the normal and impaired glucose tolerance groups.

Adult↗
PubMed1991

Clinical and biochemical findings in parents of children with vitamin D-dependent rickets Type II.

Vitamin D-dependent rickets type II is a rare disease caused by a disorder of the receptor for 1, 25-dihydroxyvitamin D (1, 25(OH)2D). Several parameters of this receptor-effector system were investigated to obtain biochemical information on the presumed heterozygotes of vitamin D-dependent rickets type II in parents of five patients and in their age-matched controls. It was found that the serum concentrations of 1, 25-(OH)2D and 24,25-dihydroxy-vitamin D (24,25(OH)2D), and the ratio of 1,25-(OH)2D/24,25-(OH)2D differed significantly in the parents from those of the patients and the respective control groups. In the parents' cultured skin fibroblasts, the activity of 25-hydroxyvitamin D-24-hydroxylase induced by 10(-8) mol/L 1, 25-(OH)2D3 ranged from 50 to 82% of that of their controls (versus 1-13% of controls for the patients). The binding capacity of the parents' [3H]1, 25-(OH)2D3 to the nucleus was 38-54% of that of their control subjects (versus 7-27% of controls for the patients). The parents' values were thus in a range between those of the patients and the control groups. These findings suggest that, in the parents, a partial impairment of the receptor system for 1, 25-(OH)2D led to an imbalance of vitamin D metabolism, thus confirming that vitamin D-dependent rickets type II is an autosomal recessive inherited disease. Serum concentrations of 1, 25-(OH)2D and 24, 25-(OH)2D may provide useful parameters for detecting heterozygotes of this disease.

24,25-Dihydroxyvitamin D 3↗
PubMed1991

Effects of deoxyadenosine on ribonucleotide reductase in adenosine deaminase-deficient lymphocytes.

To explore the relationship between ribonucleotide reductase and immunodysfunction in adenosine deaminase deficiency, the effects of deoxyadenosine on ribonucleotide reductase in ADA-deficient lymphocytes was investigated. An assay system for ribonucleotide reductase in intact permeabilized lymphocytes was developed to approximate physiological conditions. The activity of cytidine diphosphate (CDP) reductase in resting but not in proliferating lymphocytes in culture was inhibited by 1 to 10 mumol/L deoxyadenosine. The resting cells were protected from the toxicity of 1 mumol/L deoxyadenosine by 5 mmol/L nicotinamide or 30 mumol/L deoxycytidine and from that of 10 mumol/L deoxyadenosine by 30 mumol/L deoxycytidine. These findings suggest that depletion of nicotinamide adenine dinucleotide might be the principal cause of death in resting lymphocytes with ADA deficiency. It is concluded that the mechanism of deoxyadenosine toxicity on non-replicating lymphocytes, which may not be mediated by ribonucleotide reductase inhibition, is closely related to the mechanism of immunodysfunction in patients with ADA deficiency.

Adenosine Deaminase↗
PubMed1991

Identification of a brain-specific 27/26-kDa extracellular protein with the monoclonal antibody to differentiated PC12h pheochromocytoma cells.

We have searched for brain-specific extracellular molecules using a library of monoclonal antibodies against surface antigens of differentiated PC12h cells. One of the monoclonal antibodies, PCH42-14, recognized a 27/26-kDa protein of 10-week-old rat brain on immunoblotting. PCH42-14 antigen was detected only in brain, especially in cerebrum, olfactory bulb, mesencephalon, hippocampus, medulla oblongata, and spinal cord. On hippocampal neuron culture, PCH42-14 antigen existed extracellularly along with the neuronal extensions.

Animals↗
PubMed1991

Analysis of factors of relevance to rapid clinical progression in HTLV-I-associated myelopathy.

In order to clarify factors of relevance to the rapid clinical deterioration in HTLV-I-associated myelopathy (HAM), we analyzed clinical and laboratory parameters of 28 patients. Patients were divided into rapid (n = 14) and slow progression groups (n = 14) by severity of paraparesis in the 5th year after onset. Clinically, only young age at onset of the disease was significantly associated with rapid clinical deterioration. Among laboratory parameters, depressed skin reactions to dinitrochlorobenzene and PPD, a depressed lymphoproliferative responses and increased CSF IgG levels were significantly associated with rapid clinical deterioration. Serum and CSF anti-HTLV-I antibodies titers were not a relevant factor in the rapid clinical deterioration. The results suggest the implication of immunopathogenic mechanisms in HAM.

Aged↗
PubMed1991

Autopsy report of HTLV-I-associated myelopathy presenting with ALS-like manifestations.

We report an autopsy case of HTLV-I-associated myelopathy (HAM) showing clinical features indistinguishable from amyotrophic lateral sclerosis (ALS). A Japanese man developed bulbar palsy and generalized neurogenic muscular atrophy with symmetrical hyperreflexia at the age of 57 and died 4.5 years after the onset. He had an increased titer of anti-HTLV-I antibodies in serum and CSF. At autopsy, the leptomeninges were thickened and infiltrated with inflammatory cells. The brain and spinal cord were atrophic. The pyramidal tracts and anterior horn cells of spinal cord were severely degenerated but degenerative changes were also found in the basal ganglia, thalamus, brainstem tegmentum, and the dorsal columns of spinal cord. In all degenerative areas, prominent infiltrations of inflammatory cells were found. The present case indicates that HAM may produce clinical features indistinguishable from ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1991

Human tumor necrosis factor-alpha augments experimental allergic encephalomyelitis in rats.

The effect of human recombinant tumor necrosis factor-alpha (TNF) on experimental allergic encephalomyelitis (EAE) was studied in Lewis rats. TNF was injected intraperitoneally at a daily dose of 1 x 10(3) or 2 x 10(4) U for 8 consecutive days from one day after sensitization with guinea-pig spinal cord in complete Freund's adjuvant. All rats in the control group developed clinical signs of EAE but recovered within 8 days after the onset. Injections of 2 x 10(4) U/day of TNF resulted in a significant prolongation of clinical EAE: clinical signs were sustained for up to 15 days after onset. Histologically, rats receiving 2 x 10(4) U/day of TNF had more severe cellular infiltrations in the spinal cord than controls. The augmentation of EAE was not found in rats receiving 1 x 10(3) U/day of TNF or TNF that had been neutralized with anti-TNF monoclonal antibody.

Animals↗
PubMed1991

Expression of synaptophysin during synapse formation between dissociated cortical neurons.

Cerebral cortical cells from fetal rats (14 days) were cultured in vitro (7-104 days). Localization of synaptophysin was examined immunocytochemically using a monoclonal antibody (SY-38) against synaptophysin. Synaptophysin-immunoreactive (SP-IR) spots were distributed on the surface of the cells. Electron-microscopic observation showed that the SP-IR staining was localized at presynaptic terminals, indicating that the SP-IR spots observed will, fluorescence microscopy represent presynaptic terminals. The time-course of the distribution of SP-IR spots was examined. SP-IR spots could not be observed in cells at 7 days in vitro (DIV). At 14 DIV, SP-IR spots could be first observed on the surface of cell bodies and neurites. Thereafter, the density of SP-IR spots on the cell bodies and neurites increased with DIV. At 42 and 104 DIV, SP-IR spots were almost continued, surrounding the neurites and cell bodies of the cultured cells. These immunocytochemical studies suggest that the dissociated 14-day fetal cerebral cortical neurons make synapses by at least 14 DIV and that the density of synapses increases with time.

Animals↗
PubMed1991

Increased 5-HT-2 receptor function as measured by serotonin-stimulated phosphoinositide hydrolysis in platelets of depressed patients.

1. The present study was undertaken to examine whether or not 5-HT-induced inositol monophosphate (IP-1) accumulation in human platelets is mediated by 5-HT-2 receptors and to assess 5-HT-2 receptor function as measured by 5-HT-stimulated IP-1 accumulation in platelets from normal controls and depressed patients before drug treatment. 2. In platelets prelabeled with 3H-myo-inositol, in Ca ion free HEPES buffer containing 10 mM LiCl, 5-HT caused a dose-dependent accumulation of IP-1 during 15 min incubation. A maximal increase in IP-1 formation was observed at 30 microM of 5-HT and its EC50 value was 4 microM. 3. Ketanserin, a selective 5-HT-2 antagonist, was a potent inhibitor of 5-HT-stimulated IP-1 accumulation with a Ki value of 12 nM, but (-)propranolol (10 microM), a 5-HT-1 antagonist, failed to block the 5-HT response. 4. The potencies of various compounds tested to inhibit 5-HT-stimulated IP-1 accumulation in human platelets correlated positively with the affinities to 5-HT-2 receptor as defined by radioligand binding in rat cerebral cortex. 5. In a group of unmedicated patients with major depressive disorder matched for age with normal control group, we found a significant increase in 5-HT (100 microM)-induced accumulation of IP-1 (150 +/- 7% of basal for depressed patients, 132 +/- 3% for controls).

Adult↗
PubMed1991

Event-related brain potentials as indicators of visual recognition and detection of criminals by their use.

An event-related potential (ERP) was recorded, using photographs as stimuli, in 12 subjects for attended, 9 subjects for non-attended conditions and 14 subjects for a simulated criminal investigation. An ERP was detected only when a subject recognized a familiar image (target) mixed with other, unfamiliar images (non-target), regardless of whether he was asked to attend to or neglect the target image. ERPs in the subject who watched each picture but tried to ignore the relevant picture (non-attended) were more activated at the parietal region than at the central region, in contrast with ERPs in the subjects who paid attention to each picture without trying to ignore the relevant picture (attended). In the simulated criminal investigation, only a simulated thief, but not a simulated innocent subject elicited ERP only after the picture of a criminal site or thing was intermingled with pictures bearing no relationship to the crime. These findings indicate that the ERP using photographs as stimuli is useful as an objective indicator of crime-relevance.

Adult↗
PubMed1991

Development of the brainstem: assessment by MR imaging.

The morphological development of the brainstem was studied by means of MR imaging. The subjects were 74 cases ranging in age from 4 months to 16 years, and 6 adult cases. The brainstem development was rapid until 4-6 years of age and thereafter it slowed down. That is the brainstem showed exponential growth (w', t', v and u). The relationship between brainstem growth and the cranium size was divided into 4 types as follows: 1) linear increase with development (s/T-O), 2) plateau (w/T-I and v/RTP-LTP), 3) down and up (u/RTM-LTM and z/RTM-LTM) and 4) exponential (t/T-P). In the values of v, z (the size of the brainstem in axial view) and t/T-P (the ratio of the midbrain and the cranium size in sagittal view), there were significant sex differences for cases of 10-16 years old. These values in male subjects were greater than those in female subjects (v, p less than 0.05, z, p less than 0.01, and t/T-P, p less than 0.05). That is the brainstem in male subjects was greater than that in female subjects.

Adolescent↗
PubMed1991

Therapeutic effect of sodium dichloroacetate on visual and auditory hallucinations in a patient with MELAS.

We report a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes who experienced visual and auditory hallucinations. His blood and cerebrospinal fluid lactate levels were remarkably elevated. Sodium dichloroacetate was administered orally at doses of 12.5 to 100 mg/kg/day. On normalization of the lactate levels, the hallucinations disappeared.

Acidosis, Lactic↗
PubMed1991

Congenital myotonic dystrophy associated with a chromosome pericentric inversion.

We report two cases of congenital myotonic dystrophy (CMyD) associated with a chromosome abnormality of pericentric inversion. Case 1 was a two-month-old boy, presented with 46 XY, inv (9) (p 11q 13). His father had the same chromosome abnormality without any clinical manifestations. His mother had clinical manifestations of myotonic dystrophy (MyD) but had no chromosomal aberration. Case 2 is a one-month-old girl, presented with 46 XX, inv (4) (p15.31q25). Her mother had clinical manifestations of MyD and the same chromosome abnormality as Case 2, but her father was normal. Our case report may be of value in adding further information on the pathogenesis of CMyD.

Chromosome Inversion↗
PubMed1991

Pain-related somatosensory evoked potentials in syringomyelia.

Pain-related somatosensory evoked potentials following CO2 laser stimulation (pain SEPs) and conventional electrically-stimulated SEPs (electric SEPs) were examined in 8 patients with syringomyelia who showed various forms of dissociated sensory loss. Unlike clinical examination using a pin or needle, pain SEP is considered to be an objective and quantitative test to investigate functions of peripheral and central sensory pathways responsible for pain-temperature sensation (A delta fibres and the spinothalamic tract). Pain SEPs were abnormal in all patients. The results were generally compatible with the degree of a clinical impairment of pain-temperature sensation. Subclinical abnormality was detected in 3 patients. Electric median nerve SEPs using the scalp reference (Fz) were normal in 6 out of 8 patients. However, anterior and posterior cervical responses using a noncephalic reference were absent or small in 7 patients. Electric SEPs following tibial nerve stimulation were normal in 7 patients. These findings suggest that the function of the ascending fibres through the dorsal columns is intact in most patients, whereas the dorsal horn, where a fixed cervical potential is generated, is impaired. Pain SEPs combined with electric SEPs therefore appear to be extremely useful for investigating physiological function in the sensory pathways in patients who show 'dissociated sensory loss' such as in syringomyelia.

Adult↗
PubMed1991

Plasma pancreatic secretory trypsin inhibitor as a marker of pancreas graft rejection after combined pancreas-kidney transplantation.

One of the major problems in clinical pancreas transplantation is the lack of a simple and sensitive marker for detecting the early process of allograft rejection. Plasma pancreatic secretory trypsin inhibitor (p-PSTI) levels were measured in recipients of combined pancreas-kidney transplants (SPKT) and isolated cadaveric renal transplants (CRT) as controls. In the postoperative courses of SPKT recipients without acute rejection episodes and any other complications, high preoperative and immediate postoperative concentrations of p-PSTI gradually declined from the third day after transplantation and returned to the baseline level (less than 87.9 ng/ml) by the 6th day, and then remained unchanged. In this study, 11 out of 17 SPKT recipients experienced 13 acute rejection episodes. Early in the rejection course, p-PSTI levels increased significantly (P less than 0.05) 1 day before the initial day of diagnosed rejection (peak value; 232.7 +/- 99.3 ng/ml), and then they decreased following antirejection therapy. In the control group, p-PSTI elevation was less dramatic (peak value: 70.5 +/- 22.8 ng/ml, P less than 0.01) and did not precede the rise in serum creatinine. We conclude that p-PSTI may be an early, sensitive, and reliable marker of clinical pancreas graft rejection.

Adult↗
PubMed1991

Correlation between high adenosine triphosphate tissue concentration and good posttransplant outcome for the canine pancreas graft after preservation by the two-layer cold storage method.

Assessment of viability of a pancreas graft during preservation is very important to avoid transplantation of a nonfunctioning allograft. In the present report the correlation between adenosine triphosphate tissue concentration at the end of cold preservation by the two-layer method and viability a of canine pancreas graft following transplantation was studied. After preservation by an original two-layer (Euro-Collins' solution/perfluorochemical) method (group 1) and a modified two-layer (University of Wisconsin solution/PFC) method (group 2) for 24, 48, 72, 96, and 120 hr (subgroups A, B, C, D, and E), the tissue concentration of ATP was determined using high-performance liquid chromatography, and the viability of the pancreas graft was tested in the canine model of segmental pancreas autotransplantation. Maintenance of normoglycemia for at least five days after transplantation was considered to indicate a viable pancreas graft. In group 1, functional success rates were A: 5/5, (100%), B: 4/4 (100%), C: 4/4, (100%), and D: 0/4 (0%), respectively. The ATP tissue concentrations were 7.47 +/- 0.47 (n = 5), 7.91 +/- 1.21 (n = 4), 8.29 +/- 0.21 (n = 4), and 4.94 +/- 1.11 (n = 4) mumol/g dry weight in groups 1A, 1B, 1C, and 1D, respectively. There was a statistically significant difference between viable groups (groups 1A, 1B, and 1C, 7.86 +/- 0.77 mumol/g dry weight [n = 13]) and the nonviable group (group D, 4.94 +/- 1.11 mumol/g dry weight (n = 4) (P less than 0.01). On the other hand, the functional success rates were 3/3 (100%), 3/3 (100%), 3/3 (100%), 5/7 (71%), and 0/3 (0%) in groups 2A, 2B, 2C, 2D, and 2E, respectively. Two of seven dogs died of causes related to the grafts (pancreatitis and thrombosis). The ATP tissue concentrations were 8.53 +/- 1.45 (n = 3), 9.64 +/- 1.77 (n = 3), 13.81 +/- 2.09 (n = 3), and 12.49 +/- 2.52 (n = 5) mumol/g dry weight in groups 2A, 2B, and 2C and in viable grafts in group 2D, respectively, but the ATP tissue concentration of nonviable grafts in group 2D and group E were 3.51 +/- 0.81 (n = 2) and 3.98 +/- 1.34 (n = 3) mumol/g dry weight, respectively. There was a statistically significant difference between viable groups (groups 2A, 2B, 2C and viable grafts in group 2D, 11.03 +/- 2.72 mumol/g dry weight [n = 14]) and nonviable groups (group E and nonviable grafts in group 2D, 3.79 +/- 1.06 mumol/g dry weight [n = 5]) (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗