Biomedical subjects
Publications and source records attributed to N Shibuya.
Mutagenicity of fly ashes and bottom ashes of rice straw and rice husk was assayed by Ames' test. With respect to rice-straw ash, the extract from the fly ash was found to be more mutagenic than that from the bottom ash. In the case of rice husk, the mutagenicity of extract from the bottom ash was stronger than that from the fly ash. The extract from rice-husk bottom ash showed the strongest mutagenic activity among the four.
Rec assay of agricultural chemicals, MCPA-E, MCPA, CNP and PCNB was conducted. It was found that MCPA-E and MCPA accelerated the growth-inhibition originally induced by Mitomycin C in the rec- strain.
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The authors report seven cases of thoracic spinal stenosis caused by thickening of the laminar arch and facet joints. Claudication was a prominent clinical feature of this disorder. Motor and sensory abnormalities were found in all cases with either segmental or peripheral distribution. Diagnosis was best made from the computerized tomography scans. Treatment consisted of extensive posterior decompression including medial facetectomy, resulting in satisfactory improvement in five of the seven patients. A review of the literature regarding this disorder is presented.
To clarify the mechanism of development of hypercalcemia in adult T-cell leukemia/lymphoma (ATLL), ten patients with a serum creatinine level less than 177 mumol/L (2 mg/dL) were examined. Although hypercalcemia was seen in only four (40%) of these patients, four of six normocalcemic patients showed hypercalciuria (greater than 5 mmol/d [greater than 200 mg/24 h]). All hypercalcemic patients exhibited high nephrogenous cyclic adenosine monophosphate (NcAMP) levels in the face of low-normal immunoreactive parathyroid hormone and reduced serum 1,25-dihydroxyvitamin D [1,25(OH)2D] concentration. Half of the hypercalciuric patients with normocalcemia also showed high NcAMP and reduced serum 1,25(OH)2D levels. Furthermore, the changes in NcAMP and serum 1,25(OH)2D concentration closely paralleled the development of hypercalcemia and hypercalciuria in two patients. These results are reminiscent of the syndrome of humoral hypercalcemia of malignancy and suggest that derangements in calcium metabolism develop by a similar mechanism in patients with ATLL. The present data also indicate the importance of the measurement of urinary calcium excretion for early detection and prevention of fatal hypercalcemia in patients with ATLL.
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Carbohydrate binding properties of a new plant lectin isolated from elderberry (Sambucus nigra L.) (SNA) bark were studied using the techniques of quantitative precipitation, hapten inhibition, and equilibrium dialysis. Purified SNA precipitates highly sialylated glycoproteins such as fetuin, orosomucoid, and ovine submaxillary mucin, but not their asialo derivatives. Hapten inhibition experiments showed that both D-Gal and D-GalNAc are weak inhibitors of SNA-glycophorin precipitation, but neither New5Ac nor Neu5Gc is an inhibitor. A series of oligosaccharides which contain the terminal Neu5Ac(alpha 2-6)Gal sequence showed an extremely high inhibitory potency (1,600-10,000 times more inhibitory than Gal). On the other hand, oligosaccharides with the Neu5Ac(alpha 2-3)Gal linkage were only 30-80 times more inhibitory than Gal, thus showing a marked preference for the 2,6-linked isomer. Hapten inhibition with Gal and its epimers suggested that the equatorial OH at C-3 and the axial OH at C-4 of the D-pyranose ring are strict requirements for binding. Conversion of the Neu5Ac residue to its 7-carbon analogue by selective periodate oxidation of its glyceryl side chain, followed by NaBH4 reduction, completely destroyed the ability of fetuin and orosomucoid to precipitate with SNA. Moreover, the same treatment of Neu5Ac(alpha 2-3)lactitol also abolished its ability to inhibit the precipitation reaction, suggesting that the glyceryl side chain of NBu5Ac (especially the C-8 and/or C-9 portion) is an important determinant for SNA. The increased inhibitory potency of various glycosides with beta-linked nonpolar aglycons suggested the presence of a hydrophibic interacting region adjacent to the carbohydrate binding site. The results of equilibrium dialysis using [3H] Neu5Ac(alpha 2-6)lactitol as ligand showed the presence of two equivalent, noninteracting carbohydrate binding sites in this tetrameric glycoprotein lectin (Ka = 3.9 X 10(5) M-1).
A retrospective analysis of the infantile acute subdural hematoma was made with special reference to its pathogenesis. In 11 of 15 cases, the hematomas were bilateral or a contralateral subdural fluid collection was present. In 7 of 11 patients who underwent operation the collection was bloody fluid and/or clotted blood. In 3 patients, a subdural membrane, as seen in adult chronic subdural hematoma, was found. In only 1 patient with unilateral hematoma was clotted blood present without subdural membrane. The thickest collection of clotted blood was in the parasagittal region. It is postulated that in most cases hemorrhage occurs after minor head injury, from the bridging veins near the superior sagittal sinus, into a pre-existing subdural fluid collection such as chronic subdural hematoma or subdural effusion with cranio-cerebral disproportion, and that infants without intracranial disproportion are unlikely to have acute subdural hematoma caused by minor head injury.
A new plant lectin from elderberry (Sambucus nigra L.) bark, which was shown by immunochemical techniques to bind specifically to terminal Neu5Ac(alpha 2-6)Gal/GalNAc residues of glycoconjugates, was immobilized onto Sepharose 4B (SNA-Sepharose) and its carbohydrate binding properties was determined using a series of standard compounds. Oligosaccharides, glycopeptides, or glycoproteins containing terminal Neu5Ac(alpha 2-6)Gal/GalNAc sequences bound to SNA-Sepharose and were eluted with 50-100 mM lactose, whereas those with Neu5Ac(alpha 2-3)Gal/GalNAc failed to bind to this column. Furthermore, the SNA-Sepharose column was capable of resolving two oligosaccharides/glycopeptides based on the number of Neu5Ac(alpha 2-6)Gal units present in each molecule. Application of this technique to two glycoproteins, fetuin and orosomucoid, revealed the presence of microheterogeneity. It was also shown that esterification of the carboxyl group of Neu5Ac units, or branching at the O-3 of the subterminal GalNAc (probably also Gal) destroyed the binding ability of the molecule.
The authors report a case of spontaneous cervical epidural hematoma in a 13-year-old boy who exhibited hematoma recurrence 3 years after the first incidence. A review of the literature indicates very few reports of the recurrence of spinal epidural hematoma.
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The effect of pertussis toxin on somatostatin-induced K+ current was examined in dissociated human pituitary tumor cells obtained from two acromegalic patients. Somatostatin-induced hyperpolarization or K+ current was observed in 20 of 23 cells in adenoma 1 and 10 of 11 cells in adenoma 2. After treatment with pertussis toxin for 24 h, these responses were completely suppressed (0/14 in adenoma 1, 0/10 in adenoma 2). Spontaneous action potentials, K+, Na+, and Ca2+ currents were well preserved after pertussis toxin treatment. When crude membrane fraction was incubated with [32P]NAD, a 41K protein was ADP-ribosylated by pertussis toxin. Hormone release was inhibited by somatostatin and this inhibition was blocked by pertussis toxin treatment.
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Three cases of scalp arteriovenous malformation (AVM) are presented and the pertinent literature is reviewed. Case 1 was a 50-year-old male who was admitted to hospital with a pulsatile mass involving the right parietal region. Selective angiography revealed a scalp AVM fed by bilateral superficial temporal and right occipital arteries. The AVM was embolized with Gelfoam pieces through catheterization and there was no evidence of recurrence of the lesion after follow-up period of three years. Case 2 was a 25-year-old male who was noticed to have a birth mark in the left occipito-parietal region and was hospitalized with a pulsatile gradually expanding mass after an episode of minor trauma in the same region. Selective angiography revealed a cirsoid type scalp AVM fed by bilateral superficial temporal and occipital arteries, and the authors performed a total resection of the mass because of selective Gelfoam embolization was not successful. Case 3 was a 49-year-old male who was hospitalized with the chief complaints of left tinnitus and pulsatile left supra-auricular mass. There was no history of trauma. Selective angiography revealed a scalp AVM fed by the left superficial temporal and occipital arteries and the authors performed a selective Gelfoam embolization and this was successful, but three months later, the AVM recurred and mainly fed by instead this was the left posterior auricular artery. Preoperative selective Gelfoam embolization followed by a total resection of the AMV with minimal blood loss.(ABSTRACT TRUNCATED AT 250 WORDS)
The interaction of the stinging nettle rhizome lectin (UDA) with carbohydrates was studied by using the techniques of quantitative precipitation, hapten inhibition, equilibrium dialysis, and uv difference spectroscopy. The Carbohydrate binding site of UDA was determined to be complementary to an N,N',N"-triacetylchitotriose unit and proposed to consist of three subsites, each of which has a slightly different binding specificity. UDA also has a hydrophobic interacting region adjacent to the carbohydrate binding site. Equilibrium dialysis and uv difference spectroscopy revealed that UDA has two carbohydrate binding sites per molecule consisting of a single polypeptide chain. These binding sites either have intrinsically different affinities for ligand molecules, or they may display negative cooperativity toward ligand binding.