Biomedical subjects
Publications and source records attributed to M Mino.
A case of mosaic 9p tetrasomy (46,XX/47,XX, + dic[9] [q21]) is reported. Clinical manifestations of the patient were generalized hypotonia, severe mental retardation and characteristic dysmorphic features of 9p tetrasomy. A brief review of the literature is also included.
We evaluated the performance of continuous non-invasive finger arterial pressure measurement using the volume-clamp technique (Finapres). This study was designed to compare finger arterial pressure with brachial blood pressure estimated by the auscultatory method in 217 children (90 boys and 127 girls) aged 4-16 years and in 38 adults (aged 18-45 years). Finger and brachial artery pressure readings were obtained consecutively from the ipsilateral side in the supine position. Finger arterial pressure waveforms were recorded in all children except 4 with small and thin fingers. There was good agreement for systolic pressure with only a slight underestimation of 1.9 mmHg and 5.1 mmHg lower for diastolic pressure. This difference most probably reflects inaccuracy of the auscultatory cuff method rather than an error in the Finapres. There was large inter-individual variability in Finapres recordings which might be due to differences in vasomotor tone, as demonstrated by systolic amplification in 5 patients with anorexia. However, Finapres showed a small within-subject variability (3.8 mmHg for systolic and 4.1 mmHg for diastolic pressure) determined in 5 patients during phenylephrine infusion, and as good reproducibility as the auscultatory method. These results suggest that finger arterial pressure measurement in children older than 6 years of age has similar accuracy as that in adults, and that this method is useful for clinical applications in children, especially for the non-invasive evaluation of autonomic control and cardiovascular reflexes involving transient and rapid blood pressure changes.
Cardiovascular responses on active standing in children with unexplained syncope were investigated with continuous non-invasive finger artery pressure monitoring (Finapres). We examined 34 symptomatic patients (13 boys and 21 girls), aged 8-16 years, and 24 age-matched controls. Finger blood pressure and heart rate were monitored continuously for 5 min in the supine position and for 10 min while standing. Ten of 34 patients developed fainting symptoms with hypotension during upright posture (fainters). In the initial standing phase (0-30 s), two prominent abnormal blood pressure responses were found in patients: a marked decrease 45 +/- 18/23 +/- 8 mmHg and a prolonged recovery time (16.5 +/- 2.9 versus 27.7 +/- 13.6 s), which appeared to be based on impaired vasoconstriction. Either or both abnormalities were observed in 21 (62%) of the 34 patients and in 2 (8%) of the controls. In addition, fainters also had a more marked increase in heart rate during standing compared with non-fainters. Our findings suggested that more than half of children with syncope had abnormal cardiovascular reflexes in the initial phase which appeared to be associated with vasodepressor syncope. The active standing test with a continuous beat-to-beat blood pressure recording has a high sensitivity in detecting abnormalities of autonomic function in patients with unexplained syncope.
Homocystinuria is an inborn error of methionine metabolism that is characterized by the premature development of arteriosclerosis. As one of the major factors in the pathogenesis of arteriosclerosis, modification of low-density lipoprotein (LDL) has received widespread attention by many investigators. In this study, to elucidate the relationship between elevated homocysteine levels and premature arteriosclerosis, we investigated the role of homocysteine in the iron-catalyzed oxidative modification of LDL. When LDL isolated from a healthy subject was incubated with homocysteine and ferric ion, a gradual decrease of polyunsaturated fatty acids (PUFA), formation of thiobarbituric acid-reactive substances (TBARS) and fluorescent substances, and the fragmentation of apoprotein B (apoB) were observed. The extent of oxidative modification was dependent on the concentration of homocysteine. Modification of LDL was suppressed until the remaining alpha-tocopherol concentration reached a critical level. When the alpha-tocopherol content of LDL was increased by 2.6-fold, both the formation of TBARS and the fragmentation of apoB were suppressed. These results suggest that homocysteine might promote iron-catalyzed oxidation of LDL and imply its role for the development of premature arteriosclerosis.
Long-term administration of a beta-carotene preparation derived from Dunaliella bardawil, a beta-carotene-rich algae, was studied in healthy young male volunteers. The daily administration of 60 mg of the beta-carotene preparation (30 mg of all-trans beta-carotene and 30 mg of 9-cis beta-carotene) was performed and beta-carotene concentrations were determined in the plasma, red blood cells (RBC), platelets (PLT), and mononuclear cells (MN). The all-trans beta-carotene level increased four-, two-, and threefold the baseline in plasma, PLT, and MN, respectively. Basal levels of 9-cis beta-carotene in plasma, PLT, and MN were low and found as one-tenth, one-fifth, and one-fifth of all-trans beta-carotene, which increased three-, two-, and 1.5-fold the baseline, respectively. Plasma and RBC alpha-tocopherol levels were not changed by the intake of beta-carotene. No side effects or toxicities were documented in any of the subjects during the administration period. In conclusion, the bioavailability of beta-carotene derived from Dunaliella bardawil was preferential for all-trans beta-carotene, although a small amount of the 9-cis form was detected in the plasma and blood cells.
We examined the age-related changes of alpha-tocopherol levels in various clinically available biosamples in order to assess the vitamin E nutritional status. During the first week of life, more than half of every sample except red blood cells showed alpha-tocopherol levels below the lower limit of normal in a control group of children aged 3-16 years. alpha-Tocopherol levels in mononuclear leucocytes and buccal mucosal cells, which possess LDL receptors, increased in response to the plasma alpha-tocopherol elevation within a week after birth. However, RBC and platelet levels did not respond so quickly. Considering the transfer of tocopherol into body tissues during LDL catabolism, the determination of tocopherol levels in cells with LDL receptors may be useful for assessing the vitamin E status and our present study suggests that the tissue vitamin E status may be marginal in neonates.
We investigated the plasma levels of alpha-tocopherol, retinol, and beta-carotene in the institutionalized elderly individuals and in young adults, together with assessment of the influence of plasma lipids for beta-carotene and alpha-tocopherol, and the effect of retinol binding protein (RBP) on retinol levels. Although plasma alpha-tocopherol levels in elderly females were significantly higher than in elderly males, there was no significant difference in the ratio of plasma alpha-tocopherol to total lipids between males and females or between the young adults and the elderly subjects. However, the plasma beta-carotene level in elderly females did not differ from those in elderly males after correction for the difference in plasma lipids levels, while a significant higher level was observed in the young females even after this correction. Thus, plasma beta-carotene levels appear to depend not only on plasma lipids, but also on other factors, while the plasma alpha-tocopherol level depends entirely on plasma lipids. A higher plasma retinol level was observed in young males than in young females, with the level in young females not differing from that in elderly subjects of both sexes. This difference in retinol levels was dependent on changes in RBP, because the ratio of retinol to RBP did not differ between males and females or between the young adults and elderly.
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A 4-month-old male infant was seen because of an asymptomatic undescended left testis and a right sided abdominal mass. CT revealed a calcified retroperitoneal tumour. Histological examination of surgical specimens showed a mature primary teratoma of the contralateral undescended testis. While this is very rare, infants with undescended testis should be carefully examined to rule out intra-abdominal malignant tumours.
A series of studies has been conducted on the synthesis of radiopaque monomers and the development of a composite resin having these monomers. Using octachlorocyclotetraphosphazene, P4N4Cl8 (4PNC), three kinds of radiopaque cyclophosphazene monomers, 4PN(Br3Ph)1-3-(EMA)7-5, were synthesized by reacting 1-3 mols of tribromophenol (Br3Ph) and 7-5 mols of 2-hydroxyethyl methacrylate (HEMA). As the monomer for an organic composite filler, 70% (wt) synthesized monomer was used with silica (OX-50) treated with silane mixed at 30% and ground after heat-polymerization and then run through a 325-mesh sieve after polymerization. As a base monomer, 25% urethane monomer (U-2TH) was mixed in 25% synthesized monomer and photosensitizer was added. The composite resin was prepared by mixing 50% organic composite filler with 50% base monomer, and polymerized with a Dentacolor XS (Kulzer) visible light-curing apparatus by irradiation for 90 s on each side, 180 s in total. Mechanical properties did not vary with the increase in the number of tribromophenol replacements. Compressive yield strength was more than 120 MPa in all cases. Transverse strength was 60-75 MPa and hardness was HK 26-30. However, the aluminum equivalent increased with the increase in the number of tribromophenol replacements. In the case of 4PN-(Br3Ph)3, the value was 8.8 mm, whereas in the case of commercial composite resin, it was 0.4-10.4 mm.
The nutritional status with respect to vitamins A and E, and beta-carotene was examined in elderly Japanese subjects in two institutions at Osaka and Kyoto. Only the plasma vitamin E level has been determined in the majority of previous investigations. In this study, vitamin E levels were determined in red blood cells (RBCs), platelets (PLT), mononuclear cells (MN), polymorphonuclear cells (PMN), and buccal mucosal cells (BMC), using HPLC with electrochemical detection. Alpha-tocopherol levels in plasma and RBCs did not differ between elderly and young adults, while those in PLT, MN, and BMC were lower in the elderly. Thus, the vitamin E status of elderly Japanese individuals appears to be inadequate of the cellular levels. The daily vitamin E intake of the elderly subjects was below the recommended dietary allowance for the Japanese population. Plasma levels of retinol and beta-carotene were also assessed. The vitamin A status did not differ between elderly and young adults on the basis of the levels of retinol and retinol-binding protein (RBP). The daily intake of retinol (as retinol equivalent) by the elderly subjects was more than 2,000 IU. With respect to beta-carotene, there was a large sex difference (female > male), which was more prominent in the young adults and became smaller in the elderly. This sex difference was partly attributable to a difference in plasma total lipids. No clear age-related trend was noted.
The molecular basis of group A xeroderma pigmentosum (XP) was investigated by Southern blot analysis of genomic DNA and Northern blot analysis of poly (A)+ RNA from patients with group A and atypical group A XP and normal controls. The clones of a patient with group A XP who had typical symptoms showed a G-->C substitution at the 3' splice acceptor site of intron 3, which is the most common mutation in Japanese group A XP patients. On the other hand, one typical group A patient and one atypical group A patient with mild skin lesions and minimal neurological abnormalities showed compound heterozygote for the splicing mutation of intron 3 and the nonsense mutation of exon 6. The other one atypical group A patient showed a homozygote of the nonsense mutation of exon 6, thus suggesting no direct correlationship between severity of neurological complication and DNA abnormality. Northern blot analysis of poly (A)+ RNA revealed that the XPAC mRNAs of group A XP cells were smaller than that of normal controls, and amounts were markedly reduced. Of three atypical group A XP patients, one showed almost normal size and amount of the XPAC mRNA, another showed as small size and reduced amount of the XPAC mRNA, while the third one showed an intermediate type between typical group A XP and normal controls.
1. Retinoic acid is an oxidative metabolite which is produced intracellularly and plays role in gene expression via nuclear retinoic acid receptor (RAR), a family of steroid receptor. Recently, clinical use of retinoic acid in acute pro-myelocytic leukemia (APL) was proposed to induce complete remission in the leukemic cells, which have the t(15:17) of chromosomal anomaly producing a different protein from the normal RAR. From this clinical view, the regulatory role of retinoic acid is becoming clear in the cells. 2. Vitamin E is an antioxidant in biological membranes to prevent from their oxidative chain reaction occurring near the location of vitamin E in the lipid layer of the membranes. Thus, the location of vitamin E, especially alpha-tocopherol differing from the other analogues, in the living body is important to assess its function. From the standpoint of view, absorption of vitamin E from the gut, its circulation in the blood, and transportation to tissues and cells will be discussed in this paper.
1. Vitamin A: There are very few reports on vitamin A deficiency in Japan because of the rising national status of nutrition, while vitamin A deficiency is still an important nutritional problem in developing and poorly developed countries. In the pediatric field, relationship between vitamin A nutrition and the mechanism for development of bronchopulmonary dysplasia have been discussed, since vitamin A acts as a protector from the keratinization of epithelial cells in the mucosal layer and the skin. The changes in the lung tissues with inadequately supplied vitamin A, probably cause the chronic lung disease resulting from mechanical ventilation in neonates, in whom the plasma vitamin A and retinol binding protein levels are usually low. 2. Vitamin E: In keeping with the view that newborn infants and especially premature infants suffer from vitamin E deficiency. On the basis of recent findings of the vitamin E content in the neonatal cells, the previous concept would agree, as an existing marginal deficiency in neonates. The neurologic deficits manifested in a beta-lipoproteinemia is confirmed to be vitamin deficiency in humans. It has also become clear that similar neurologic impairment occurs in other chronic fat malabsorptive states, such as cholestatic liver diseases, extensive resection of the gut. More recently several patients with spinocerebellar degeneration from vitamin E deficiency without other evidence of malabsorption in whom progression of the diseases is terminated by the vitamin E therapy (isolated vitamin E deficiency) have been reported. The above items are discussed.
The beta-carotene concentrations in plasma, blood cells and buccal mucosal cells were determined by high-performance liquid chromatography with electrochemical detection. This method was 1,000 times more sensitive than the conventional spectrophotometric method. Polymorphonuclear cells and red blood cells had lower beta-carotene levels than the other cells. After oral administration of 580 mg/day of all-trans beta-carotene to human male volunteers for a week, the beta-carotene concentrations in all cell types increased at least several times above the original levels.
A case of paraganglioma arising in the posterior mediastinum in a 29-year-old man diagnosed by magnetic resonance imaging is reported. Excision of mediastinal paraganglioma is often hazardous because of its rich vascular supply and tendency to involve surrounding structures. Magnetic resonance imaging is valuable for the preoperative diagnosis of this vascular tumor as well as for determination of its resectability and appropriate surgical procedure.
Levels of serum manganese superoxide dismutase (Mn-SOD) in normal children aged from 1 to 14 years and children with various hematological and malignant diseases were determined by enzyme-linked immunosorbent assay (ELISA). In the normal children, the serum Mn-SOD levels gradually increased in proportion to age. By 8 years of age, the Mn-SOD level was nearly at the adult level. The normal values of serum Mn-SOD (mean +/- SD) of children below 4 and above 8 years old were 48 +/- 10.2 ng/ml and 84 +/- 22.5 ng/ml, respectively. Assuming the upper limit of normal Mn-SOD level in serum to be the mean value +/- 2 SD of children at each age, high serum levels of Mn-SOD were found for 8 of 12 patients with neuroblastoma, three of four patients with Wilms tumor, and four of five patients with acute myeloid leukemia. The patients with neuroblastoma exhibited a transient increase in Mn-SOD following chemotherapy, but after 1 week the levels decreased markedly to the control levels. The changes in serum Mn-SOD levels in the patients with neuroblastoma correlated well with the levels of neuron-specific enolase. Mn-SOD was intensely stained in bone marrow cells of patients whose cancer cells had moved into the bone marrow. High levels of Mn-SOD were also found in cultured human neuroblastoma cells. These data indicate that Mn-SOD is expressed in neuroblastoma cells, may serve as one of the diagnostic and prognostic markers for the neuroblastoma, and may be useful to predict the effectiveness of chemotherapy for neuroblastoma and the recurrence of this disease.