[Activities of volunteers in hospitals. Volunteers are a great help for the nursing department].
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Humans↗
Biomedical subjects
M Doi
Publications and source records attributed to M Doi.
Structure of ascidiacyclamide as the ethanol water solvate, a cytotoxic cyclic peptide from Ascidian.
The X-ray crystal structure determination of the C2H5OH.H2O solvate of ascidiacyclamide (C36H52N8O6S2), a cytotoxic cyclic peptide from marine tunicate Ascidian, revealed a C2-symmetric saddle-shaped rectangular conformation of the molecule. The water and ethanol molecules are located on the crystallographic diad axis and are held by hydrogen bonds and van der Waals contacts with the polar ring N atoms and nonpolar D-Val side-chain atoms, respectively. The molecular conformation and the interaction with solvent molecules are nearly the same as those of the compound with C2H5OH.2H2O [Ishida, In, Doi, Inoue, Hamada & Shioiri (1992). Biopolymers, 32, 131-143].
Animals↗
DNA-binding characterization of a novel anti-tumour benzo[a]phenazine derivative NC-182: spectroscopic and viscometric studies.
NC-182 is a novel anti-tumour compound having a benzo[a]phenazine ring. Fluorescence, absorption and c.d. spectroscopy, as well as viscometric titrations, were systematically performed to investigate the interaction mode of this drug with DNA and its effect on DNA conformation, based on comparative measurements with distamycin (DNA minor-groove binder) and daunomycin (DNA-base intercalator). NC-182 was found to be a potent intercalator of DNA, especially the B-form DNA, although no specificity was observed against the base-pair. The binding of NC-182 to B-DNA behaves biphasically, depending on the molar ratio (r) of drug to DNA: NC-182 acts to render the B-form structure rigid at relatively low r value and to promote the transformation of B- to non-B forms at high r values. It was also shown that NC-182 promotes the unwinding of Z-form DNA to B-form. Viscometric, u.v. 'melting' and c.d. experiments further showed that (1) the DNA duplex structure is thermally stabilized by intercalation with NC-182 and (2) the intercalation of NC-182 into a poly(dA).2poly(dT) DNA structure thermally stabilizes the triplex structure, resulting in a melting point close to that of the duplex structure; the melting curves of triplex and duplex structures coincide at r > 0.06. These observations make a significant contribution to our understanding of the biological properties of this novel benzo[a]phenazine derivative, a new anti-tumour tumour agent against multidrug-resistant and sensitive tumours.
Antineoplastic Agents↗
Conformational analysis of elcatonin in solution.
The conformational characteristics of elcatonin, an analogue of eel calcitonin having a disulfide bond Cys1-Cys7 replaced by an ethylene linkage between residues 1 and 7, have been analyzed in aqueous trifluoroethanol solutions. Circular dichroic spectra of elcatonin and eel calcitonin itself reveal the presence of alpha-helices at trifluoroethanol concentrations above 15%. The spectral changes caused by the trifluoroethanol content of the solutions are interesting. An isosbetic point is detected for eel calcitonin indicating that a conformational transition occurs between two states, namely alpha-helical and random coil states. On the other hand, the CD curves of elcatonin at less than 15% trifluoroethanol deviate from the isosbetic point while those at higher concentration are similar to those of eCT. This can probably be attributed to the third element of the ordered structure of elcatonin which is formed in 15% trifluoroethanol. The solution conformation of elcatonin in a mixture of 60% water and 40% trifluoroethanol has been determined by the combined use of 1H-NMR spectroscopy and distance geometry calculations. The conformation is characterized by an amphiphilic alpha-helix between Thr6 and Thr21, which extends into the constrained cyclic portion of the molecule to Thr6. The third structural element of elcatonin found in the CD analysis is detected by some turn structures in the region between residue 1 and Ser5 in the calculated structure.
Amino Acid Sequence↗
Nucleotide sequence of the structural gene for the penicillin-binding protein 2 of Staphylococcus aureus and the presence of a homologous gene in other staphylococci.
The structural gene for penicillin-binding protein 2 (PBP2) of Staphylococcus aureus was cloned and sequenced. The nucleotide sequence of the 2,458-bp chromosomal fragment was determined, and the 2,148-bp coding region for PBP2 was identified. Determination of ten N-terminal amino acids of the PBP2 protein indicated that N-terminal methionine had been removed from the primary translational product. Thus, PBP2 is comprised of 715 amino acids with a molecular mass of 79,147. Nucleotide sequences having some homology with the PBP2 gene and proteins cross-reactive with anti-PBP2 antibody were detected in some other species of staphylococci by polymerase chain reaction and Western blot analysis, respectively.
Amino Acid Sequence↗
A case of uveitis associated with idiopathic retroperitoneal fibrosis.
We treated a patient with nongranulomatous panuveitis associated with idiopathic retroperitoneal fibrosis who had symptoms of abdominal pain, severe fever, leg edema, and blurred vision. A high C-reactive protein level, a high erythrocyte sedimentation rate, anemia, and abnormalities of the immune system were seen. Retrograde pyelography disclosed persistent ureteral obstruction. A computed tomographic scan and magnetic resonance imaging showed a dense plaque of fibrous tissue around the kidney and hydronephrosis. Biopsy disclosed fibrosis infiltrated with lymphocytes, plasma cells, histiocytes, and eosinophils. A moderate degree of cellular inflammation in the anterior chamber and cystoid macular edema were present at ocular examination. We believe idiopathic retroperitoneal fibrosis to be a new cause of uveitis of suspected autoimmune origin.
Blood Sedimentation↗
Patellamide A, a cytotoxic cyclic peptide from the ascidian Lissoclinum patella.
The structure of crystals of patellamide A (13-methyl-9,23-bis(1-methylethyl)-2,16-bis(1-methylpropyl)-14,-28-di oxa-7,21- dithia-3,10,17,24,29,30,31,32- octaaza-pentacyclo[24.2.1.1(5,8).1(12,15).1(19,22]dotriac onta-1(29),5,- 8(30),15(31),19,22(32)-hexaene-4,11,18,25-tetraone methanol solvate monohydrate, C35H49N8O6S2.-CH4O.H2O), a cytotoxic cyclic peptide having a non-C2-symmetric methyl group, shows the C2-symmetric and saddle-shaped rectangular conformation where the methyl group is disordered into two C2-symmetric positions. The water and methanol solvents were located on the crystallographic diad axis and were held by hydrogen bonds and van der Waals contacts with the polar ring N atoms and non-polar D-Val side-chain atoms, respectively.
Animals↗
Histopathology of rabbit eyes with intravitreous silicone-fluorosilicone copolymer oil.
Silicone-fluorosilicone copolymer oil is characterized by being heavier than water (density, 1.16 g cm-3) and low viscosity (175-185 centistokes) compared with currently used intraocular silicone oils (density, 0.97 g cm-3 and 1000-5000 centistokes). This oil is potentially useful as an operative tool and a tamponade on the inferior retina in complicated retinal detachment. We evaluate the ocular response clinically and histopathologically within 8 weeks in rabbit phakic eyes to the purified silicone-fluorosilicone copolymer oil after vitreous cavity injection, and compared the oil tolerance with purified silicone oil (0.97 g cm-3, 5000 centistokes) and perfluorotetradecahydrophenanthrene for ophthalmic use (Vitreon, 2.03 g cm-3, 8.03 centistokes) which are currently used as operative tools and as internal retinal tamponade agents in retinal detachment surgery. Because of their low viscosity, silicone-fluorosilicone copolymer oil and perfluorotetradecahydrophenanthrene were easier to inject into the eye than silicone oil. Silicone-fluorosilicone copolymer oil and perfluorotetradecahydrophenanthrene occupied the inferior portion in the eye, and silicone oil occupied the superior portion. Fewer discrete oil droplets and weaker vessel attenuation of medullary rays than in the perfluorotetradecahydrophenanthrene-injected eyes were seen in silicone-fluorosilicone-copolymer-oil-injected eyes. Histopathologically, all retinas injected with silicone-fluorosilicone copolymer oil were normal within 4 weeks. The silicone-fluorosilicone copolymer oil dispersion did not induce histopathological changes within 8 weeks. However, thinning or disappearance of the outer plexiform layer was seen in the inferior retina in some silicone-fluorosilicone-copolymer-oil-injected eyes at 6-8 weeks. A similar effect was found in the superior retina of a silicone-oil-injected eye at 8 weeks. More severe changes such as thinning or disappearance of the outerplexiform layer, thinning and disorganization of the photoreceptor layer, and migration of the receptor cell nuclei to the photoreceptor layer were found in the inferior retina of perfluorotetradecahydrophenanthrene-injected eyes after 2 weeks. Intraocular silicone-fluorosilicone copolymer oil tolerance until about 2 months post-injection is similar to silicone oil and better than perfluorotetradecahydrophenanthrene. Silicone-fluorosilicone copolymer oil may be useful intraoperatively and as a temporary vitreous substitute in cases of inferior retinal detachment.
Animals↗
Effects of midazolam and diazepam as premedication on heart rate variability in surgical patients.
We have examined the effects of midazolam 0.06 mg kg-1 i.m. and diazepam 0.2 mg kg-1 orally as premedication on the spectral components of heart rate (HR) variability in 24 elderly patients aged 65-87 yr and 24 young patients aged 18-35 yr undergoing elective surgery. The low-frequency/high-frequency (LF/HF) ratio of HR variability increased after arrival in the operating room in elderly patients who received no premedication, but not in young patients. In elderly patients who received midazolam or diazepam, the LF/HF ratio did not increase. However, diazepam increased the low-frequency component and the total power of HR variability in both young and elderly patients. We conclude that cardiac sympathetic nerve activity increased after arrival in the operating room in the elderly, that midazolam or diazepam reduced this increase and that diazepam caused an increase in the total power of HR variability that has not been observed for other agents.
Administration, Oral↗
Direct expression of a synthetic gene in Escherichia coli: purification and physicochemical properties of human initiation factor 4E.
An artificial synthetic gene coding for human eIF-4E was cloned into an expression vector and direct expression was attempted in Escherichia coli [BL21(DE3) strain] under the control of T7 promoter. The active gene product which was induced in high yield (ca. 4 mg/100 ml) by isopropyl-beta-D-thiogalactopyranoside was purified to homogeneity by a two-step chromatographic procedure with a good yield (ca. 74%), and was confirmed to be recombinant human eIF-4E by amino acid composition and sequence analyses, isoelectric focusing, and absorption spectral measurements. The identity of three-dimensional structures between the recombinant and native human eIF-4Es was confirmed by CD and fluorescence measurements.
Amino Acid Sequence↗
Spatial distribution of thoron and radon concentrations in the indoor air of a traditional Japanese wooden house.
A radon-thoron discriminative passive dosimeter has been developed that can estimate both radon (222Rn) and thoron (220Rn) concentrations at the same time. Two polycarbonate films are installed as solid-state nuclear track detectors in the dosimeter housing. One film registers alpha tracks originating from predominantly thoron and its progeny together with a small contribution from radon, and the other film registers alpha tracks originating from radon and its progeny together with a negligible contribution from thoron. The lower detection limit is estimated to be 2.9 Bq m-3 for the radon concentration and 9.0 Bq m-3 for the thoron concentration for 2 mo exposure. Preliminary measurements from 1991-1992, in a traditional Japanese wooden house located in Kyoto, indicated that the indoor thoron concentration increases exponentially as the interior mud (or plaster-coated) wall is approached. A soil-based plaster commonly used in Japanese wooden houses to fill walls (or as a surface coating on the walls) is the probable source of the indoor thoron. Since thoron is not measured by the usual radon measurements, and the majority of Japanese houses are made of wood, attention should be paid to indoor thoron and its decay products, which may give a significant fraction of the total natural radiation exposure to the general public.
Air Pollutants, Radioactive↗
Characterization of Japanese wooden houses with enhanced radon and thoron concentrations.
Indoor thoron and radon concentrations were surveyed in the 42 rooms of 21 houses in Hiroshima Prefecture with a radon-thoron discriminative dosimeter in 1992. The survey estimated the average indoor thoron concentration to be 84.7 +/- 15.6 Bq m-3 and that of radon to be 25.6 +/- 1.1 Bq m-3 at 20 cm from the interior wall. The results indicated the potential risk of indoor thoron in the Japanese style wooden houses. Multivariate regression analysis among some factors which characterize each of the houses examined and concentrations of radon and thoron suggested that enhanced concentration of indoor thoron was often observed in a typical Japanese style room with interior soil wall and tatami flooring. Characterization of the rooms with enhanced levels of thoron showed that mud-based plaster wall material was probably the source.
Air Pollution, Indoor↗
Vertical distribution of outdoor radon and thoron in Japan using a new discriminative dosimeter.
Passive measurements of outdoor radon and thoron concentrations were conducted from June 1992 to June 1993 at a monitoring station over a soil area (10 m x 6 m) in Chiba city, Japan. The measurement period was divided into 4 parts to investigate seasonal variations of radon and thoron concentrations. Ten passive radon-thoron discriminative dosimeters (R-T dosimeters) were placed in duplicate at 5 different altitudes to show the vertical distributions of outdoor radon and thoron concentrations. Outdoor radon concentrations showed no significant difference within 1.0 m above the ground, and the annual average of outdoor radon concentration was 3.85 +/- 0.19 (SE) Bq m-3. Annual averages of outdoor thoron concentrations at 0.04, 0.15, 0.25, 0.70, and 1.0 m above the ground were 40.5 +/- 4.4, 22.5 +/- 3.7, 13.9 +/- 3.1, 9.5 +/- 2.9 (SE) Bq m-3, and < 9.0 Bq m-3; the lower detection limit of the dosimeter, respectively, and their vertical profiles, n(z) (Bq m-3), were expressed well by the formula n(z) = alpha z beta. Vertical profiles of the atmospheric turbulent diffusion coefficient were also estimated from the observed thoron profiles, as expressed by the power function K(z) = AzB, of which B values were estimated to vary from 1.034 to 1.609 if averaged thoron exhalation rates during the measurement periods were within 0.3 to 2.8 (Bq m-2 s-1).
Altitude↗
Electrophoretic karyotypes of Candida yeasts recurrently isolated from single patients.
Candida strains were isolated repeatedly from single patients during recurrent episodes of Candida infection in a hospital, and their electrophoretic karyotypes were analyzed by pulsed-field gel electrophoresis using CHEF system. When only C. albicans (in 6 patients) or C. glabrata (in 1 patient) were recurrently isolated, their karyotypes from each patient were almost identical to one another, suggesting that they carried single type of the yeast. When multiple species were recovered from single patients (6 cases), the karyotypes of the most frequently recovered yeast species were almost identical with respect to each patient. The electrophoretic karyotype analysis has been proved to be useful for epidemiological studies because the method can tell not only the species identification but also the differences among the strains of the same species.
Adult↗
Comparative conformational analyses of mu-selective dermorphin and delta-selective deltorphin-II in aqueous solution by 1H-NMR spectroscopy.
Two-dimensional 1H-NMR methods have been used to obtain complete proton resonance assignments and possible solution conformations of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) and deltorphin-II (H-Tyr-D-Ala-Phe-Glu-Val-Val-Gly-NH2), naturally occurring mu- and delta-selective opioids, respectively, in order to examine the conformational characteristics that are closely related to the selectivities towards mu/delta-opioid receptors. With the use of the proton-proton distances derived from ROESY measurements in aqueous solution, 50 possible 3D structures are generated by means of distance geometry calculations. The conformers which satisfy the distance constraints and the torsion angles estimated from JNHC alpha H vicinal coupling constants within the allowable range are then subjected to molecular dynamics simulations for 10 ps after equilibration. Although dermorphin and deltorphin-II are both in equilibrium among many flexible conformers, some conformational differences are observed between these peptides: many conformers of dermorphin show a structure rounded at the N-terminal Tyr-D-Ala-Phe-Gly-Tyr and C-terminal Gly-Tyr-Pro-Ser-NH2 moieties, which are almost at right angles to each other, while those of deltorphin-II are characterized by a 'hook'-shaped backbone structure in which the nearly extended conformation of the Val-Val-Gly-NH2 sequence is located under the folded conformation of the N-terminal Tyr-D-Ala-Phe-Glu sequence. The possible relationship between these conformational characteristics and the mu/delta-opioid receptor selectivities is discussed.
Amino Acid Sequence↗
Conserved and novel structural characteristics of enantiomorphic Leu-enkephalin. X-ray crystal analysis of Leu-enkephalin enantiomer, L-Tyr-Gly-Gly-L-Phe-L-Leu and D-Tyr-Gly-Gly-D-Phe-D-Leu.
The crystal of the Leu-enkephalin racemate (L-Tyr-Gly-Gly-L-Phe-L-Leu and D-Tyr-Gly-Gly-D-Phe-D-Leu) was obtained as a centrosymmetric space group. Crystal data: C28H37N5O7 x 1.5H2O, Mw = 582.6, triclinic, space group P1, a = 11.176(3), b = 16.115(3), c = 10.204(4) A, alpha = 92.41(3), beta = 104.86(2), gamma = 85.35(2)degrees, V = 1770(1)A3, Z = 2; F(000) = 640, mu(CuK alpha) = 6.50 cm-1, D chi = 1.081 g cm-3. The structure was determined by X-ray diffraction. The conformation of the Leu-enkephalin racemate was classified into the extended form which has been often observed in natural enkephalin. The symmetry-related molecules were connected by hydrogen bonds and arranged in an antiparallel fashion. The molecular packing showed a sheet structure similar to that of natural enkephalin.
Amino Acid Sequence↗
Characteristic molecular packing in the crystal structure of tert-butoxycarbonyl-L-phenylalanyl-L-methionine methyl ester.
The molecular conformation and association of the peptide Boc-L-Phe-L-Met-OMe have been studied in the solid state by X-ray diffraction. The peptide crystallizes in the orthorhombic system, space group P2(1)2(1)2(1), with cell parameters of a = 9.821(2), b = 25.394(6), c = 28.714(8) A, V = 7161(3) A3. The structure has been solved by direct methods and refined to a final R of 0.079 for 5464 independent reflections with Fo > or = sigma(Fo). The crystal consists of three independent molecular conformations per asymmetric unit. Respective peptide backbones adopt an extended conformation with the side-chains of Phe and Met residues being arranged below and above the backbone chains. Contrary to the sheet structure most frequently observed in the crystal packing of the extended peptide conformations, three independent molecules lie spirally along the c-axis and form a pin-wheel-like crystal packing. The sheet structures formed by two of three independent molecules are almost at right angles to the backbone of the remaining molecule. This molecular packing mode would provide a possible interaction model between the intersecting beta-sheet structure and single-strand structure of polypeptide.
Amino Acid Sequence↗
Spontaneous perforation of pyometra: a case report.
Spontaneous perforation is a rare complication of pyometra and is usually associated with uterine cervical occlusion. We report a very rare case of spontaneously perforated pyometra without cervical occlusion. A 56-year-old woman with severe abdominal pain was admitted to our hospital. Exploratory laparotomy was performed because of suspicion of gastro-intestinal perforation with generalized peritonitis. There was no perforation of the stomach, gallbladder, or bowels, but examination of the uterus revealed a perforation of the uterine fundus. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Pathological investigation of the surgical specimen revealed endometritis and myometritis of the uterus; but there was no evidence of malignancy, and the cervical canal was patent. Although spontaneously perforated pyometra is rare, the condition must be born in mind with regard to elderly women with acute abdominal pain.
Abdominal Pain↗