[A case of ileal carcinoid tumor penetrating mesocolon with asthma attack].
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Aged↗
Biomedical subjects
H Takeuchi
Publications and source records attributed to H Takeuchi.
Effect of hypobaric hypoxia on fiber type composition of the soleus muscle in the developing rat.
The fiber type composition of the soleus muscle was investigated in male Sprague-Dawley rats exposed to hypobaric hypoxia of 460 mm Hg from 5 to 12 weeks of age. The muscle fibers were classified as fast-twitch oxidative (FO) and slow-twitch (S) on the basis of adenosine triphosphatase (ATPase) and succinate dehydrogenase (SDH) reactions. Intermediate fibers (INT) with intermediate ATPase and high SDH reaction intensities were also examined. A type shift of muscle fibers from FO to INT and S was found in the control group during development. After exposure to hypoxia, the hypoxia group had a significantly greater percentage of FO fibers than the age-matched control group. There was no significant change in the total number of fibers in the muscle during development and after exposure to hypoxia. These results indicate that the increased percentage of FO fibers found in the developing rat under hypoxic conditions is due to a hypoxia-induced inhibition of the type shift of muscle fibers from FO to S during development.
Animals↗
[Detection of mutant adenine phosphoribosyltransferase genes by polymerase chain reaction-single strand conformation polymorphism analysis].
Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis is a rapid and sensitive method to identify point mutations in a given sequence of genomic DNA. We tried to apply the PCR-SSCP to the diagnosis of adenine phosphoribosyltransferase (APRT) deficiency, which is an autosomal recessive hereditary disease leading to 2,8-dihydroxyadenine urolithiasis. Genomic APRT genes, with or without mutations, were amplified and labeled simultaneously with 32P-dCTP by PCR. When run in a 6% polyacrylamide gel containing 10% glycerol, two types of mutant genes, APRT*Q0 and APRT*J, gave bands clearly distinct from those of the respective normal APRT genes. Since heterozygotes as well as homozygotes for these mutant APRT genes can be detected in 2 days, PCR-SSCP should be a valuable method in the diagnosis of APRT deficiency and in screening a large population for APRT mutant genes.
Adenine Phosphoribosyltransferase↗
[Indiana continent urinary reservoir: technical modifications and late complications].
From October, 1987 through September, 1991, 39 patients underwent construction of Indiana pouch for cutaneous urinary diversion. There were 35 men and 4 women, and their ages ranged from 38 to 77 years (a mean age of 62 years). After the first 8 cases, Indiana pouch was constructed with several modifications which included complete detubularization of the cecum, construction of the pouch augmented with U-shaped ileal patch, and the use of stapled plication. There was no major early complication related to the pouch but one postoperative death of blood transfusion related graft versus host disease. End results were evaluated in 37 patients who were followed for 3 to 49 months. Late complications related to urinary reservoir occurred in 8 patients. The early two patients experienced pouch deformity due to incomplete detubularization of the colonic segment. Two patients had difficult catheterization due to a dilatation of the plicated ileum. One patient had metabolic acidosis requiring hospitalization. Patients perform self-catheterization 4-5 times during the day and 0-2 times at night for volumes ranging from 300 to 1,000 cc. Of 37 patients 34 achieved acceptable urinary continence and one had significant leakage requiring cutaneous bag. The remaining two patients suffered mild nocturnal incontinence. Follow up examination with excretory urography showed no upper urinary tract obstruction except one with unilateral hydronephrosis due to ureteroanastomotic stricture. Reservoirgraphy showed no reflux into the upper urinary tract in all the follow up cases.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Raman spectroscopic study on the structure of ribonuclease F1 and the binding mode of inhibitor.
The structure of RNase F1 in aqueous solution has been studied by Raman spectroscopy and compared with that of a homologous enzyme, RNase T1. RNase F1 contains less beta-sheet and alpha-helical structure and more irregular structure than RNase T1. The strength of hydrogen bonding is weak in the beta-sheet and strong in the alpha-helix compared to that of RNase T1. Two disulfide bridges take the gauche-gauche and gauche-trans conformations, respectively. The overall hydrogen bonding of nine Tyr side chains in RNase F1 is very similar to that in RNase T1. Both of two His residues have pKa values around 8.2, which are close to those of the His residues in the active site of RNase T1. Upon binding of 2'-GMP, the hydrogen bonding of some Tyr side chains changes to a more proton-donating state. 2'-GMP is strongly hydrogen bonded with the enzyme at N7 of the guanine ring and takes the C3' endo-syn conformation. The binding mode of the inhibitor is identical to that found for RNase T1. In spite of significant differences in secondary structure, the molecular architecture of the active site seems to be highly conserved.
Amino Acid Sequence↗
Interaction of lower hybrid wave with fast ions injected by neutral beam on the JT-60 tokamak.
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Journal Article↗
Raman spectroscopic characterization of tryptophan side chains in lysozyme bound to inhibitors: role of the hydrophobic box in the enzymatic function.
The state of H-bonding and the hydrophobic interaction of six tryptophan side chains in lysozyme bound to substrate-analogous inhibitors were investigated by combining H----D exchange labeling and Raman difference spectroscopy. The frequency of the W17 band due to Trp-63 shifts downward upon inhibitor binding, indicating a specific and strong H-bond formation between the N1 site of the side chain and the inhibitor molecule. On the other hand, the H-bonding state of Trp-62 in the complex is as weak as that in inhibitor-free lysozyme, suggesting no contribution of this residue to the inhibitor binding. Intensity increases of W17 and W18 bands observed upon inhibitor binding are, respectively, ascribed to an increase at Trp-28 and a decrease at Trp-111 in hydrophobic interactions with the environment. The environmental changes are explained consistently by a movement of the Met-105 side chain sandwiched by two indole rings of Trp-28 and 111 in the direction from Trp-111 to Trp-28. The sandwich structure in a core domain, hydrophobic box, and its rearrangement are considered to play an important role in the enzymatic function of lysozyme.
Acetylglucosamine↗
APGW-amide as an inhibitory neurotransmitter of Achatina fulica Ferussac.
APGWamide (L-Ala-L-Pro-Gly-L-Trp-NH2) was purified from the ganglia of an African giant snail (Achatina fulica Ferussac). This peptide inhibited (hyperpolarized) more than half of the Achatina neurone types tested. This produced an outward current with the membrane conductance increase of RAPN (right anterior pallial neurone) under voltage clamp. The ED50 of the peptide was 6.2 x 10(-6) M (95% confidence limit: 5.0-7.8 x 10(-6) M) and the Emax was 3.9 +/- 0.2 nA. The effects were due to a membrane permeability increase to K+. The peptide is proposed as an inhibitory neurotransmitter of the Achatina neurones.
Animals↗
Slow inward current induced by achatin-I, an endogenous peptide with a D-Phe residue.
Following a preliminary report on the isolation of a neuroactive tetrapeptide, achatin-I (Gly-D-Phe-L-Ala-L-Asp) that has a D-phenylalanine residue, from the Achatina fulica ganglia, the pharmacological features of this peptide on Achatina giant neurones were now worked out in detail. Of the eight possible stereoisomers, only achatin-I markedly, and [D-Ala3]achatin-I slightly, induced a slow inward current (Iin) with an increase in membrane conductance (g) of the identifiable neurones, tonically autoactive neurone (TAN), dorsal-right cerebral distinct neurone (d-RCDN) and periodically oscillating neurone (PON) which had been tested previously. Of 23 types of neurones tested, 10 types including the three mentioned were excited by achatin-I, whereas no neurone was inhibited. The ED50 of achatin-I for the neurones tested were 0.2-2.7 x 10(-5) M, and that for PON was the lowest. The Hill coefficients of achatin-1. 0.62-0.80, derived from 1.0 Emax values of achatin-I for producing Iin, 4.2-6.3 nA, were significantly greater than those of [D-Ala3]achatin-I, 1.8-3.4 nA. Iin of TAN and d-RCDN induced by achatin-I was blocked in the Na(+)-free state, but unaffected in the Ca2(+)-free (replaced with Co2+), Cl(-)-free or K(+)-enriched (3.0X) state, indicating that the current was produced by the g increase in response to Na+. However, the Iin was partially blocked by tetrodotoxin 10(-4) M. We propose that achatin-I is an excitatory neurotransmitter on Achatina neurones.
Amino Acid Sequence↗
B-Z transition of poly(dG-m5dC) induced by binding of Lys-containing peptides.
Effects of oligopeptides containing Lys residues on the conformation of poly(dG-m5dC) have been investigated by circular dichroism spectroscopy. Lys-Ala-Lys (KAK) and its longer analogs with Lys-Ala repeats are found to convert the B-form polynucleotide to the Z form very efficiently. The ability to induce the B-Z transition is characteristic of alternating Lys-Ala sequences and increases exponentially with increasing number of the repeats. The heptapeptide KAKAKAK has an ability comparable with that of spermine, one of the most effective inducers hitherto known. The present results provide the first example of the B-Z transition of poly(dG-m5dC) induced by peptide binding.
Alanine↗
Characterization of polymorphs of tranilast anhydrate and tranilast monohydrate when crystallized by two solvent change spherical crystallization techniques.
Spherically agglomerated crystals of tranilast (oral antiallergic agent) with improved availability in vitro, as well as improved micromeritic properties such as flowability and packability, were prepared by a novel spherical crystallization technique. The agglomerates of tranilast were found to be composed of new monohydrate I, II, or III, depending on the crystallization solvent and the procedure employed. With dehydration by heating, monohydrate I transformed to the stable alpha form directly. On the other hand, monohydrates II and III converted to the amorphous and beta forms, respectively, followed by further transformation to the alpha form at 110 and 150 degrees C, respectively. The amorphous and beta forms of agglomerates were easily prepared by storing the monohydrates under 0% RH at 30-40 degrees C. Monohydrate II and the amorphous form of the agglomerate with high surface energy could enhance the solubility and the dissolution rate of tranilast. A phase diagram of polymorphs of agglomerated tranilast was constructed to exhibit their interconversions under various humidities and temperatures.
Chemical Phenomena↗
Effects of dietary calcium, magnesium and phosphorus on the formation of struvite stones in the urinary tract of rats.
After feeding various diets we studied the effects of dietary calcium, magnesium and phosphorus on the formation of struvite stones in rats with urinary tract infections, and also studied the effects of the administration of vitamin D3 and aluminium gel on stone formation. A low-magnesium diet decreased urinary magnesium and prevented stone formation, but a medium-calcium diet did not significantly decrease stone weight. A high-calcium diet decreased urinary phosphorus and inhibited stone formation. A high-calcium and high-phosphorus diet decreased urinary excretion of magnesium and inhibited stone formation. Although the administration of vitamin D3 did not inhibit stone formation, aluminium gel decreased the urinary level of phosphorus and prevented stone formation. A marked decrease in urinary magnesium and/or phosphorus may prevent struvite stone formation in rats with urinary tract infections.
Aluminum↗
In vitro bone resorption by isolated multinucleated giant cells from giant cell tumour of bone: light and electron microscopic study.
The behaviour of multinucleated giant cells (GCs), obtained from a giant cell tumour of the tibia and cultured on glass coverslips or on devitalized bone slices, was studied using light and electron microscopy. Monitoring the GCs on bone slices by phase-contrast microscopy revealed that they had removed calcified bone matrix resulting in excavation of lacunae, with subsequent lateral extension and perforation of the bone slices. Electron microscopy demonstrated for the first time that the GCs responsible for exavating lacunae had two specific membrane modifications, ruffled border and clear zone, and showed basically similar cytoplasmic fine structures to those of osteoclasts. Fluorescence images of the GCs on glass and on bone after rhodamine-conjugated phalloidin staining revealed that most of the GCs had an intensely fluorescent peripheral band composed of a number of F-actin dots called podosomes. Some GCs showed unusual arrangements of podosomes suggesting abortive attempts at GC formation. We have demonstrated that the band structure of the GCs cultured on bone is intimately involved in bone resorption. Two stromal cell types could be recognized. The predominant type, which seemed to be the only neoplastic element because of its proliferative capability, showed quite different fine structural and cytoskeletal features from the GCs. The other type, which was much less frequent and seemed not to proliferate, had morphological similarities to the GCs, and seemed to be their precursor. Importantly GCs cultured on bone and the osteoclasts share common structures for adhesion to and resorption of bone, strongly supporting the view that the GCs of the giant cell tumour of bone are potentially active bone resorbers and can be regarded as osteoclasts.
Adult↗
Salivary fibronectin in man: an immunoblotting, radioimmunoassay and immunohistochemical study.
An antiserum and monoclonal antibody against plasma fibronectin recognized a 230-kDa, intact fibronectin molecule when 1000-fold diluted human plasma was subjected to immunoblot analysis. Immunoblot analysis of the parotid saliva demonstrated that the rabbit antiserum to human plasma fibronectin bound to five molecules (200, 110, 85, 75 and 65 kDa), other than the 230-kDa, intact fibronectin molecule, while the mouse monoclonal antibody recognized only the 230-kDa molecule. The 230-kDa type was not found in whole saliva with either the antiserum or monoclonal antibody. The antiserum reacted with 85-, 75- and 33-kDa molecules, and the monoclonal antibody recognized 75-, 33- and 20-kDa molecules in the whole saliva. Radioimmunoassay revealed that the mean +/- SD of fibronectin concentration in parotid saliva was 2.5 +/- 1.4 ng/ml (n = 20) and 149.8 +/- 46.2 ng/ml (n = 30) for whole saliva. Immunoperoxidase staining with rabbit antiserum and the mouse monoclonal antibody showed positive cytoplasmic staining of cells in the intralobular and interlobular ducts in parotid, submandibular, and sublingual glands. No acinar cells were stained.
Adult↗
Structure-activity relationship studies on the endogenous neuroactive tetrapeptide achatin-I on giant neurons of Achatina fulica Ferussac.
The structure-activity relationships of achatin-I, a neuroactive peptide containing a D-phenylalanine residue, for producing excitatory effects on three different types of Achatina neurons, PON, TAN and d-RCDN, were studied under the voltage clamp method. Of the peptides examined, only Gly-Gly-D-Phe-L-Ala-L-Asp (IV). D-Phe-L-Ala-L-Asp (V) and Gly-D-Phe-L-Ala-L-Asn (XVI) produced an inward current with increased membrane conductance similar to achatin-1 (I). The structure-activity relationship was essentially the same for the three Achatina neuron types. The equiactive molar ratios (EMRs) of the active peptides vs. achatin-I (I) were calculated from their dose-response curves: 8 - 60 for Gly-Gly-DPhe-L-Ala-L-Asp (IV), 200 - greater than 250 for D-Phe-L-Ala-L-Asp (V) and greater than 200 for Gly-D-Phe-L-Ala-L-Asn (XVI). These values indicate that the achatin-I receptor in the Achatina neurons is highly structure-specific.
Amino Acid Sequence↗
Metabolism of aspartame and its L-phenylalanine methyl ester decomposition product by the porcine gut.
The intestinal metabolism of aspartame (N-L-alpha-aspartyl-L-phenylalanine methyl ester; APM) and its L-phenylalanine methyl ester (PME) decomposition product was evaluated in six young pigs. Equimolar doses (2.5 mmol/kg body weight) of APM, PME, and L-phenylalanine (PHE) administered to the proximal jejunum produced similar increases in portal blood PHE concentrations. Methanol, nondetectable in portal blood after PHE ingestion, increased markedly after administration of either APM or PME. Portal blood aspartate concentrations were unchanged after PME and PHE administration, but increased significantly after APM administration. Increases in portal blood PHE concentrations were significantly greater than were increases in aspartate concentrations following APM administration. Neither APM, PME, nor aspartyl-phenylalanine (AspPhe) were detected in portal or vena caval blood following administration of any test compound. Steady-state perfusion of the small intestine with APM showed a net intraluminal appearance rate of AspPhe at 36% of the disappearance rate of APM. During steady-state PME perfusion, PHE had a significantly greater net appearance rate than during APM perfusion. Methanol appearance rates were slightly, but not significantly, higher during PME than during APM perfusions. The data suggest that (1) APM is hydrolyzed to AspPhe and both APM and PME are hydrolyzed to their constituent amino acids and and methanol prior to entering the portal circulation; (2) AspPhe is an important intraluminal intermediate in aspartame metabolism; and (3) aspartate is rapidly metabolized by the enterocyte.
Animals↗
Reconstruction of the skull base using a silicone plate during transsphenoidal surgery.
Our operative experience of reconstruction of the skull base using a silicone plate during rhinoseptoplastic transsphenoidal surgery is described. A suitably shaped plate can be easily and quickly made from a large silicone block of the type that is widely used in cosmetic surgery. The plates can be distinguished on magnetic resonance images postoperatively. We consider that this technique is of use not only for repairing the sellar floor, but also for closing a wide defect of the skull base.
Adolescent↗
An application of tetrazolium (MTT) colorimetric assay for the screening of anti-herpes simplex virus compounds.
A rapid and sensitive procedure was developed for in vitro evaluation of anti-herpes simplex virus (HSV) agents. The procedure is based on spectrophotometrical assessment for viability of virus- and mock-infected cells via in situ reduction of a tetrazolium dye MTT, which has already been used for the detection of anti-human immunodeficiency virus (HIV) agents (Pauwels et al., 1988). Monolayer cells such as human embryonic fibroblast, VERO, or HeLa cells were not suitable for this purpose. Among the non-adherent cell lines examined for susceptibility to HSV type 1 (HSV-1), a B-lymphoblastoid cell line NC-37 was found to be the most sensitive. The cell line was found to have a good correlation between the viable cell number and the reduction of MTT. In addition, centrifugation of the virus-infected cells resulted in further increase of the sensitivity of NC-37 cells to HSV-1. After optimization, the method proved to be as sensitive as plaque reduction. The system simplifies significantly the assay procedures and thus permits the evaluation of larger numbers of compounds for anti-HSV-1 activity.
Animals↗