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Biomedical subjects

J Doi

Publications and source records attributed to J Doi.

18 recordsLinked to original sources
PubMed1995

Detection and geometric modeling of molecular surfaces and cavities using digital mathematical morphological operations.

We developed a digital method based on mathematical morphological operations to obtain three types of surfaces: van der Waals surface, solvent-accessible surface, and molecular surface, to extract the cavities on the surface and interior part of the molecule and to extract the ligand portions in contact with the cavities. The molecular surface, the cavities and the portions, and the heme region are visualized using solid modeling. The method enables us to obtain the volumes of the cavities and inhibitor portions and the areas of the surfaces. Solid modeling enables us to obtain cross-sections at arbitrary positions. This will have considerable utility in docking studies.

Computer Graphics↗
PubMed1995

[Clinical study on antimicrobial prophylaxis following extracorporeal shock wave lithotripsy].

One hundred and sixty one patients with upper urinary stones were examined for antimicrobial prophylaxis following extracorporeal shock wave lithotripsy (ESWL). They were divided into two groups, the low-risk group (n = 133) and high-risk group (n = 28), according to the risk factors of urinary tract infection. The patients in the low-risk group were further randomized into two groups which were orally given ofloxacin for 7 days after ESWL (Group A, n = 66), no antimicrobial (Group B, n = 67). The patients in the high-risk group were randomly subdivided into three groups which were given flomoxef intravenously for 2 or 3 days and ofloxacin for 4 or 5 days thereafter (Group C, n = 10), flomoxef only for 2 or 3 days and no drugs later (Group D, n = 10), ofloxacin for 7 days (Group E, n = 8). In all of the patients in the low-risk group, during the 7 days after ESWL, fever elevation was observed in only 1.5% of patients, and bacteriuria in 10.0% on the 7th day. There was no difference in frequency of fever elevation and bacteriuria following ESWL between Group A and Group B. These findings indicate that prophylactic antimicrobial after ESWL treatment is not necessary for low risk patients with urinary tract infections. In the high-risk group, the over-all rates of fever elevation and bacteriuria were 21.4% and 24.0% respectively. The difference of effectiveness among the prophylactic regimens of the three groups (Group C, D, E) was not shown.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Dynamics of transfer RNAs analyzed by normal mode calculation.

Normal mode calculation is applied to tRNAPhe and tRNAAsp, and their structural and vibrational aspects are analyzed. Dihedral angles along the phosphate-ribose backbone (alpha, beta, gamma, epsilon, zeta) and dihedral angles of glycosyl bonds (chi) are selected as movable parameters. The calculated displacement of each atom agrees with experimental data. In modes with frequencies higher than 130 cm-1, the motions are localized around each stem and the elbow region of the L-shape. On the other hand, collective motions such as bending or twisting of arms are seen in modes with lower frequencies. Hinge axes and bend angles are calculated without prior knowledge. Movements in modes with very low frequencies are combinations of hinge bending motions with various hinge axes and bend angles. The thermal fluctuations of dihedral angles well reflect the structural characters of transfer RNAs. There are some dihedral angles of nucleotides located around the elbow region of L-shape, which fluctuate about five to six times more than the average value. Nucleotides in the position seem to be influential in the dynamics of the entire structure. The normal mode calculation seems to provide much information for the study of conformational changes of transfer RNAs induced by aminoacyl-tRNA synthetase or codon during molecular recognition.

Motion↗
PubMed1994

Energy minimization method using automata network for sequence and side-chain conformation prediction from given backbone geometry.

Globular proteins have high packing densities as a result of residue side chains in the core achieving a tight, complementary packing. The internal packing is considered the main determinant of native protein structure. From that point of view, we present here a method of energy minimization using an automata network to predict a set of amino acid sequences and their side-chain conformations from a desired backbone geometry for de novo design of proteins. Using discrete side-chain conformations, that is, rotamers, the sequence generation problem from a given backbone geometry becomes one of combinatorial problems. We focused on the residues composing the interior core region and predicted a set of amino acid sequences and their side-chain conformations only from a given backbone geometry. The kinds of residues were restricted to six hydrophobic amino acids (Ala, Ile, Met, Leu, Phe, and Val) because the core regions are almost always composed of hydrophobic residues. The obtained sequences were well packed as was the native sequence. The method can be used for automated sequence generation in the de novo design of proteins.

Bacterial Proteins↗
PubMed1992

[Effect of isoflurane, enflurane and halothane on hemodynamics during the induction of anesthesia].

The effects of isoflurane(I), halothane(H) and enflurane(E) on hemodynamics of 36 patients (12, 11 and 13, respectively) were studied during the inhalation of 1.5 MAC of each anesthetics before the surgery. Mean arterial pressure(MAP), heart rate(HR), cardiac index(CI), systemic vascular resistance index(SVRI), and stroke volume index (SVI) were measured noninvasively using the automatic blood pressure manometer and the ultrasonic Doppler method (Accucom). MAP decreased with I, E and H, but a larger decrement was observed with E than with H. CI and SVI with H were less than with E. SVRI decreased with I and E but a significant difference was observed between E and H. Each value with I was between those with H and E. These results indicate that isoflurane causes the depression of blood pressure mostly by its effect to decrease afterload during the induction of anesthesia, although its depressing effect is less than that of enflurane.

Adult↗
PubMed1992

[Clinical evaluation of the laryngeal mask airway using capnogram].

The laryngeal mask airway (LMA) was clinically evaluated using capnogram in patients who breathed spontaneously under the combination of general and spinal anesthesia. Using the LMA, the airway was maintained without jaw lift and no remarkable hemodynamic change was observed during its insertion and removal. Capnogram was useful to confirm the intact airway and to monitor the respiration. Respiratory depression was observed after thiopental administration and enflurane inhalation. The respiration recovered promptly following the increase of respiratory rate (RR) and tidal volume at first, and it made a further recovery following increase in RR. The use of the LMA under light inhalation anesthesia is hence a useful combination with regional anesthesia.

Adult↗
PubMed1992

[Anesthetic management of the patient with a permanent pacemaker].

Anesthetic management of two patients with a permanent pacemaker is reported; patient no. 1 had the VVI mode pacemaker and patient no. 2 had the DDD mode pacemaker. In patient no. 1, the hypotensive response of the 'pacemaker syndrome' occurred during general anesthesia. Patient no. 2 had no anesthetic problems but careful attention should be paid to the DDD mode pacemaker, because the newer widely used dual lead systems (DDD) are more susceptible to electromagnetic interference. Anesthetists often encounter patients with pacemakers. Knowledge of pacemakers available of the increasingly wide range is necessary to ensure safe management of these patients, many of whom are frail and elderly.

Aged↗
PubMed1990

[A case of adrenal myelolipoma associated with adrenogenital syndrome].

Myelolipoma is a benign non-functioning tumor, and the number of documented cases is increasing in recent years. We report a case of adrenal myelolipoma associated with adrenogenital syndrome. A 65-year-old woman presented with a complaint of abdominal discomfort. CT showed a mass with abundant fatty density in the left adrenal gland suggesting myelolipoma. She was small and thin. External genitalia had a female appearance, but showed type III abnormality in Prader's classification with clitoral hypertrophy. She had a history of primary amenorrhea. Endocrinological examination revealed marked increase in the 17 alpha-hydroxyprogesterone (or 17-OHP) and pregnanetriol levels. On the basis of clinical features and laboratory values, simple virilizing type congenital adrenal hyperplasia due to 21-hydroxylase deficiency was made. The left adrenal tumor was surgically removed and histologically proved to be myelolipoma. Tumor-uninvolved adrenal area adjacent to myelolipoma showed adrenocortical hyperplasia. To our knowledge, this is the first reported case of adrenal myelolipoma to be associated with congenital adrenal hyperplasia, due to 21-hydroxylase deficiency in Japan. The etiology of myelolipoma remains to be not clarified but our case suggests involvement of endocrine disorder in the development of this tumor.

Adrenal Gland Neoplasms↗
PubMed1989

[Giant liposarcoma of the spermatic cord: a case report].

A case of giant liposarcoma of the spermatic cord was reported. A 75-year-old man was admitted with a 25-year history of a slowly growing left scrotal solid mass without trans-illumination. The removed huge mass measuring 26.0 x 16.5 x 20.0 cm and weighing 4,500 g was confirmed to be a well-differentiated liposarcoma according to WHO classification. The patient died of acute pneumonia 5 months later, although the postoperative course was uneventful and he had no sign of recurrence.

Aged↗
PubMed1984

Intestinal uptake and metabolism of auranofin, a new oral gold-based antiarthritis drug.

Auranofin, 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranosato-S-(triethy lphosphine)- gold(I), an experimental antiarthritis pharmaceutical, metabolized in contact with hamster or rat gut wall to yield the deacetylated form of the drug. This product, 1-thio-beta-D-glucopyranosato-S-(triethylphosphine)gold(I), passed through hamster or rat intestinal wall in an everted gut experiment. The metabolite was separated by high-performance liquid chromatography and characterized by retention time, chemical reactivity to yield a known product, and comparison to a synthetic sample of the metabolite.

Animals↗