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Biomedical subjects

T Nishiyama

Publications and source records attributed to T Nishiyama.

At least 37 records · Page 2Linked to original sources
PubMed2001

PhaR, a protein of unknown function conserved among short-chain-length polyhydroxyalkanoic acids producing bacteria, is a DNA-binding protein and represses Paracoccus denitrificans phaP expression in vitro.

A putative regulatory protein, PhaR, which was identified in the polyhydroxyalkanoic acid synthetic locus (phaZCPR) in Paracoccus denitrificans, was investigated. The PhaR protein purified from a recombinant Escherichia coli was estimated to be 22 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, being consistent with the mass calculated from the nucleotide sequence. The molecular mass was determined to be 93 kDa by size-exclusion chromatography, suggesting that the protein formed a tetramer. A gel mobility shift assay showed that PhaR specifically bound to the intergenic region of phaC--phaP. In a cell-free protein synthesis system using E. coli S30 extract, the expression of the phaP gene was repressed by the addition of purified PhaR. These results suggest that PhaR is a DNA-binding protein and may play a role in the regulation of phaP gene expression.

Bacterial Proteins↗
PubMed2001

Irregular activation of individual sweat glands in human sole observed by a videomicroscopy.

Sweat secretion from individual sweat glands on the human sole was observed in four male subjects by using a videomicroscope and correlated with sudomotor neural activity recorded from the tibial nerve by means of microneurography. Individual sweat glands could be distinguished as active, less active and inactive according to the incidence of sweat secretion during spontaneous sweating. The threshold amplitude of the sudomotor burst necessary for sweat secretion varied from gland to gland. The number of sweat secretion was significantly related to the threshold amplitude. Sweat glands often failed to produce sweat secretion even when a suprathreshold burst occurred: only 46.1+/-3.8% (mean +/- S.E.M.) of the suprathreshold bursts elicited sweat secretion. Failure of the sweat secretion tended to appear after several bursts occurred consecutively with short intervals. In spite of the variability in sweat gland activity, the number of sweat glands recruited was linearly related to the amplitude of the sudomotor burst (P < 0.001). Thus, although sweat secretion from each sweat gland depends primarily on the intensity of sudomotor neural activity. the activity of each sweat gland may fluctuate temporally as the result of irregular activation of sudomotor fibers and possibly some intrinsic factors of the gland.

Adult↗
PubMed2001

(S)-preferential detoxification of 4-hydroxy-2(E)-nonenal enantiomers by hepatic glutathione S-transferase isoforms in guinea-pigs and rats.

In guinea-pig liver cytosol, racemic 4-hydroxy-2(E)-nonenal (HNE), a reactive and highly toxic product released from biomembranes by lipid peroxidation, was detoxified (S)-preferentially by GSH conjugation mediated by glutathione S-transferases (GSTs) and (R)-preferentially by NAD(+)-dependent oxidation mediated by aldehyde dehydrogenase (ALDH). The GST-mediated detoxification of the HNE enantiomers proceeded at much higher rates than that mediated by ALDH in guinea-pig liver cytosol. All the major guinea-pig GSTs, A1-1, M1-1, M1-2 and M1-3*, isolated from guinea-pig liver cytosol also catalysed the (S)-preferential conjugation of the HNE enantiomers. The liver and other major tissues of guinea-pigs had no immunologically detectable level of a putative GSTA4-4 orthologue, which exists as a minor GST protein in rat, mouse and human livers and exhibits extremely high catalytic activity towards HNE. All the hepatic rat GSTs, A1-1(2), A1-3, A4-4, M1-1, M1-2 and M2-2, also catalysed the (S)-preferential conjugation of HNE enantiomers.

Aldehydes↗
PubMed2001

Synergistic analgesic effects of intrathecal midazolam and NMDA or AMPA receptor antagonists in rats.

PURPOSE: To investigate the interaction of midazolam and N-methyl-D-aspartate (NMDA) receptor or -amino-3-hydroxy-5-methyl isoxazole-4-propionic acid (AMPA) receptor antagonist on the effects of persistent inflammatory nociceptive activation. METHODS: Male Sprague-Dawley rats were implanted with lumbar intrathecal catheters and were tested for their responses to subcutaneous formalin injection into the hindpaw. Saline, midazolam (1 to 100 microg), AP-5 (I to 30 microg), a NMDA receptor antagonist, or YM872 (0.3 to 30 microg), an AMPA receptor antagonist was injected intrathecally 10 min before formalin injection. The combinations of midazolam and AP-5 or YM872 in a constant dose ratio based on the 50% effective dose (ED50) were also tested and were analysed with an isobologram. RESULTS: Dose-dependent effects were observed with midazolam (ED50 was 1.34 microg and 1.21 microg in phase 1 and 2 of the formalin test, respectively), AP-5 (7.64 microg and 1.4 microg) and YM872 (0.24 microg and 0.21 microg). Synergistic effects in both phases were obtained when combining midazolam with AP-5 or YM872. The ED50 of midazolam decreased to 0.012 microg (phase 1) and 0.27 microg (phase 2) with AP-5 and to 0.09 microg (phase 1) and 0.35 microg (phase 2) with YM872 (P < 0.01). CONCLUSIONS: These results suggest a functional coupling of benzodiazepine-aminobutyric acid (GABA)A receptor with NMDA and AMPA receptors in acute and persistent inflammatory nociceptive mechanisms in the spinal cord.

2-Amino-5-phosphonovalerate↗
PubMed2001

The effects of facial fanning on thermal comfort sensation during hyperthermia.

We studied how facial fanning during hyperthermia improves the thermal comfort sensation. Experiments were carried out on ten male subjects. They were immersed in hot water at 40 degrees C for 45 min. At 20 min and 35 min, fanning (1 m x s(-1)) was applied to their faces for 5 min. Core temperature (Tc) measured as esophageal temperature (Tes) and tympanic temperature (Tty) continued to rise during the immersion, but temporarily decreased during fanning with a delay of 2 or 3 min. Skin temperatures (Ts) on the forehead and cheek continued to increase slightly during immersion, but decreased immediately after the start of fanning. During immersion before face fanning, the time trend of thermal sensation towards the warm level was similar to that of skin temperature on the face, whereas the time trend of thermal comfort ratings towards the uncomfortable level was similar to that of Tc. The scores of both thermal sensation and thermal comfort were reduced significantly immediately after the start of fanning, and their time courses were different to those of Ts and Tty. These results support previous reports that thermal sensation depends on skin temperature, and that thermal comfort depends on both the skin and core temperatures. Moreover, they indicate that both thermal sensation and comfort ratings are affected by the dynamic responses of the cutaneous thermoreceptors when fanning is applied to the face during hyperthermia.

Adult↗
PubMed2001

Comparison of Neisseria gonorrhoeae isolates from the genital tract and pharynx of two gonorrhea patients.

Neisseria gonorrhoeae was isolated simultaneously from urethral and pharyngeal specimens of two gonorrhea patients. The pair of isolates from one of the two patients were identical in auxotype, pulsed-field gel electrophoresis pattern, and antimicrobial susceptibility, which indicated that both sites in that patient were infected with the same strain of N. gonorrhoeae. However, the two isolates from the other patient had different properties, indicating that the two sites in the second patient were infected with different strains. The gonococcal infections in these patients failed to respond to initial treatment with sparfloxacin or sulbactam/ampicillin, because the causative strains of N. gonorrhoeae were resistant to the respective antibiotics. Variable patterns and routes of gonococcal infection have recently been discovered in individual patients, suggesting that specimens for bacterial isolation should be taken not just from one site but from various sites that might be infected. This method may contribute to the successful treatment and epidemiological investigation of gonococcal infections.

Adult↗
PubMed2001

Atropine prevents midazolam-induced core hypothermia in elderly patients.

STUDY OBJECTIVE: To test the hypothesis that core temperature is well preserved when atropine and midazolam are combined. DESIGN: Randomized, blinded study. SETTING: Department of Anesthesia, Yamanashi Medical University. PATIENTS: 40 elderly, ASA physical status I and II patients (aged more than 60 years). INTERVENTIONS: Patients were randomly assigned (n = 10 per group) to premedication with: 1) saline control; 2) midazolam 0.05 mg/kg; 3) atropine 0.01 mg/kg; and 4) midazolam 0.05 mg/kg combined with atropine 0.01 mg/kg. All premedication was given on the ward at approximately 8:30 am, approximately 30 minutes before induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Core temperatures were measured at the right tympanic membrane. Mean skin temperature was calculated as 0.3 x (T(chest) + T(arm)) + 0.2 x (T(thigh) + T(calf)). Fingertip perfusion was evaluated using forearm minus fingertip and calf minus toe, skin-surface temperature gradients. Temperatures were evaluated at the time of premedication and 30 minutes later, just before induction of anesthesia. Core temperature remained nearly constant in the control patients (0.1 +/- 0.2 degrees C; mean +/- SD), whereas it decreased significantly in the patients given midazolam alone (-0.3 +/- 0.1 degrees C). Atropine alone increased core temperature (0.3 +/- 0.2 degrees C), although the increase was not statistically significant. The combination of midazolam and atropine attenuated the hypothermia induced by midazolam alone (0.0 +/- 0.2 degrees C). Initial skin-temperature gradients exceeded 0 degrees C in all groups, indicating that the patients were vasoconstricted. The gradients were unchanged by premedication with saline or atropine. Midazolam significantly decreased the gradient (-1.8 +/- 1.1 degrees C), as did the combination of midazolam and atropine (-1.4 +/- 0.9 degrees C). CONCLUSIONS: The thermoregulatory effects of benzodiazepine receptor agonist and cholinergic inhibitors oppose each other, and the combination leaves core temperature unchanged.

Aged↗
PubMed2001

Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol.

BACKGROUND AND OBJECTIVE: To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure. METHODS: Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg-1 propofol and 0.5 mg kg-1 ketamine or 2 mg kg-1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg-1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation. RESULTS AND CONCLUSIONS: Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.

Anesthesia↗
PubMed2001

Establishment of gene-trap and enhancer-trap systems in the moss Physcomitrella patens.

Because of its simple body plan and ease of gene knockout and allele replacement, the moss Physcomitrella patens is often used as a model system for studies in plant physiology and developmental biology. Gene-trap and enhancer-trap systems are useful techniques for cloning genes and enhancers that function in specific tissues or cells. Additionally, these systems are convenient for obtaining molecular markers specific for certain developmental processes. Elements for gene-trap and enhancer-trap systems were constructed using the uidA reporter gene with either a splice acceptor or a minimal promoter. Through a high rate of transformation conferred by a method utilizing homologous recombination, 235 gene-trap and 1073 enhancer-trap lines were obtained from 5637 and 3726 transgenic lines, respectively. The expression patterns of these trap lines in the moss gametophyte varied. The candidate gene trapped in a gene-trap line YH209, which shows rhizoid-specific expression, was obtained by 5' and 3' RACE. This gene was named PpGLU, and forms a clade with plant acidic alpha-glucosidase genes. Thus, these gene-trap and enhancer-trap systems should prove useful to identify tissue- and cell-specific genes in Physcomitrella.

Blotting, Northern↗
PubMed2001

Osteogenic sarcoma of the prostate.

A 76-year-old man was treated with bilateral orchiectomy, estramustine phosphate and pelvic irradiation for prostate cancer. Osteogenic sarcoma of the prostate developed 18 months after the treatment. Postmortem examination revealed that the tumor was 8 cm in diameter and had infiltrated into the bladder and rectal walls and had resulted in peritoneal dissemination. There was no distant metastasis. Macroscopically, the tumor was ashen, firm and relatively homogenous and diffusely spread. Histologically, it was composed of spindle and pleomorphic cells, which were making osteoid with calcification. There was no ordinary tubular formation as shown in adenocarcinoma of the prostate. No positive immunostaining for prostate-specific antigen, epithelial membrane antigen and cytokeratin (AE-1, AE-3) were confirmed. Positive immunostaining for nonepithelial marker vimentin was confirmed. The ultimate diagnosis was osteogenic sarcoma of the prostate.

Adenocarcinoma↗
PubMed2001

Antioxidative activity of hydroxylamines. ESR spectra of radicals derived from hydroxylamines.

The antioxidative activity of hydroxylamines was evaluated for the oxidation of tetralin at 61 degrees C and linoleic acid micelles in an aqueous dispersion at 37 degrees C, induced by an azo initiator. The antioxidative efficacy of the hydroxylamines for the oxidation of tetralin was smaller than that of alpha-tocopherol. However, the hydroxylamines showed more potent antioxidative activity than that of the alpha-tocopherol against the oxidation of linoleic acid micelles. On the basis of the results of an ESR study and the oxidation product obtained, it is suggested that active position in hydroxylamines depend not only on hydroxyl hydrogen-atom, but also on the allylic hydrogen atom.

Antioxidants↗
PubMed2001

Orthostatic hypotension in elderly persons during passive standing: a comparison with young persons.

BACKGROUND: The present study was aimed at clarifying the mechanism of orthostatic hypotension (OH) that occurs in elderly persons and at investigating assisting methods to prevent OH by evaluating changes in autonomic nervous system (ANS) activity and cerebral circulation of elderly persons when engaged in passive standing. METHODS: Eight elderly volunteers and 9 young volunteers gave informed consent to participate in the study. Two experimental conditions were established: (i) "active standing," in which the subjects stood on their own with guidance from an assistant, and (ii) "passive standing," in which the subjects were placed in a standing position completely by an assistant. ANS was determined before and after standing by measuring the heart rate variability. The reaction of the ANS was evaluated on the basis of low-frequency power (LF: 0.05--0.15 Hz) and high-frequency power (HF: 0.15--0.4 Hz), which were separated from the R-R interval data by power spectral analysis using the fast Fourier transformation. Cerebral perfusion was measured over the right frontal region using a near-infrared spectroscopy cerebral oxygen monitor. RESULTS: The main findings were: (i) Transient decreases in blood pressure occurred immediately after standing in both the young and elderly subjects. (ii) The LF:HF ratio increased significantly ( p <.05) immediately after active standing in the young subjects, whereas this ratio increased in the elderly subjects after some delay. (iii) The LF:HF ratio increased significantly ( p <.01) immediately after passive standing in the young subjects, whereas this ratio decreased significantly ( p <.05) in the elderly subjects. (iv) In the elderly subjects, the total hemoglobin (HbT) and oxyhemoglobin showed the greatest decrease during the 15-second period after standing. The maximum changes in the HbT with passive standing differed significantly ( p <.01) from those observed during active standing. CONCLUSIONS: Our findings emphasize the need to devise bioengineered means that allow elderly persons to exert themselves, to maintain or improve muscle contractility and ANS function, while providing minimum assistance for standing.

Adult↗
PubMed2001

Isolation of homeodomain-leucine zipper genes from the moss Physcomitrella patens and the evolution of homeodomain-leucine zipper genes in land plants.

Homeobox genes encode transcription factors involved in many aspects of developmental processes. The homeodomain-leucine zipper (HD-Zip) genes, which are characterized by the presence of both a homeodomain and a leucine zipper motif, form a clade within the homeobox superfamily and were previously reported only from vascular plants. Here we report the isolation of 10 HD-Zip genes (named PPHB:1-PPHB:10) from the moss Physcomitrella patens. Based on a phylogenetic analysis of the 10 PPHB: genes and previously reported vascular plant HD-Zip genes, all of the PPHB: genes except Pphb3 belong to three of the four HD-Zip subfamilies (HD-Zip I, II, and III), indicating that these subfamilies originated before the divergence of the vascular plant and moss lineages. Pphb3 is sister to the HD-Zip II subfamily and has some distinctive characteristics, including the difference of the a(1) and d(1) sites of its leucine zipper motif, which are well conserved in each HD-Zip subfamily. Comparison of the genetic divergence of representative HD-Zip I and II genes showed that the evolutionary rate of HD-Zip I genes was faster than that of HD-Zip II genes.

Amino Acid Sequence↗
PubMed2001

The analgesic interaction between intrathecal clonidine and glutamate receptor antagonists on thermal and formalin-induced pain in rats.

UNLABELLED: Clonidine, an alpha(2) adrenergic receptor agonist, inhibits glutamate release from the spinal cord. We studied the interaction of intrathecally administered clonidine and glutamate receptor antagonists on acute thermal or formalin induced nociception. Sprague-Dawley rats with lumbar intrathecal catheters were tested for their tail withdrawal response by the tail flick test and paw flinches produced by formalin injection after intrathecal administration of saline, clonidine, AP-5 (a N-methyl-D-aspartate receptor antagonist), or YM872 (an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist). The combinations of clonidine and the other two agents were also tested by isobolographic analyses. Motor disturbance and behavioral changes were observed as side effects. The ED(50) values of clonidine decreased from 0.26 microg (tail flick), 0.12 microg (Phase 1) and 0.13 microg (Phase 2) to 0.036 microg, 0.006 microg, and 0.013 microg with AP-5, and 0.039 microg, 0.057 microg, and 0.133 microg with YM872, respectively. Side effects were attenuated in both combinations. In conclusion, spinally administered clonidine and AP-5 or YM872 exhibited potent synergistic analgesia on acute thermal and formalin-induced nociception with decreased side effects in rats. IMPLICATIONS: Combinations of a spinally administered alpha(2) adrenergic receptor agonist and an a N-methyl-D-aspartate receptor antagonist or an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist exhibited potent synergistic analgesia in acute thermal and inflammatory-induced nociception with decreased side effects.

Adrenergic alpha-Agonists↗
PubMed2001

Propofol-induced bronchoconstriction: two case reports.

IMPLICATIONS: Bronchoconstriction was induced by anesthetic induction with propofol in two patients with allergic diseases. One had severe bronchospasm improved by epinephrine. Propofol should be used with caution in patients with allergic disease.

Adult↗
PubMed2001

The synergistic interaction between midazolam and clonidine in spinally-mediated analgesia in two different pain models of rats.

UNLABELLED: Both midazolam, a benzodiazepine gamma-aminobutyric acid type A receptor agonist, and clonidine, an alpha2-adrenergic receptor agonist, induce spinally-mediated analgesia. We investigated the analgesic interaction of spinally-administered midazolam and clonidine in their effects on acute and inflammatory nociception. Rats implanted with lumbar intrathecal catheters were injected intrathecally with saline (control), midazolam (1 to 100 microg), or clonidine (0.1 to 3 microg) to test for their responses to thermal stimulation to the tail (tail-flick test) and subcutaneous formalin injection into the hind paw (formalin test). The effects of the combination of midazolam and clonidine on both stimuli were tested by isobolographic analysis by using the 50% effective doses. The general behavior and motor function were examined as side effects. When combined, the 50% effective doses of midazolam (clonidine) decreased from 1.57 microg (0.26 microg) to 0.29 g (0.05 microg) in the tail-flick test and from 1.34 microg (0.12 microg) and 1.21 microg (0.13 microg) to 0.05 microg (0.005 microg) and 0.13 microg (0.015 microg) in Phase 1 and 2 of the formalin test, respectively. Side effects did not increase by using the combination. These results suggest a favorable combination of intrathecal midazolam and clonidine in the management of acute and inflammatory pain after proper neurotoxicologic studies. IMPLICATIONS: Spinally-administered midazolam, a benzodiazepine, and clonidine, an alpha2-adrenergic receptor agonist, have significant synergistic effects on thermally-induced acute and formalin-induced inflammatory pain.

Adrenergic alpha-Agonists↗
PubMed2001

Hemolysis in stored red blood cell concentrates: modulation by haptoglobin or ulinastatin, a protease inhibitor.

OBJECTIVE: Polymorphonuclear leukocyte elastase may injure various tissues. The release of polymorphonuclear leukocyte elastase induced by various stimuli was reported to be inhibited by a protease inhibitor, ulinastatin. In stored blood preparations, polymorphonuclear leukocyte elastase increases depending on the storage days as hemolysis increases. We hypothesized that polymorphonuclear leukocyte elastase might be one of the factors inducing hemolysis in stored blood. Haptoglobin binds to free hemoglobin to reduce hemolysis. The purpose of the study was to investigate the effects of ulinastatin on hemolysis in blood preparations in comparison with haptoglobin. DESIGN: In vitro study. SETTING: Laboratory in a university hospital. SUBJECTS: Nine 2-day-old packs of red blood cell concentrates (CRC) in 400 mL each of mannitol, adenine, glucose, phosphate, and citrate (MAP) (MAP-CRC) from the Japan Red Cross Society. INTERVENTIONS: Each MAP-CRC was divided into three different packs of equal amount and was treated with 10 mL of saline (control group), 200 units of haptoglobin, or 50,000 units of ulinastatin. They were stored at 4 degrees C. MEASUREMENTS AND MAIN RESULTS: Supernatant concentrations of total and free hemoglobin, total haptoglobin, polymorphonuclear leukocyte elastase, and potassium were measured for 25 days. Free haptoglobin concentration was calculated. Total and free hemoglobin concentrations increased significantly depending on the storage days in the control group, whereas haptoglobin and ulinastatin groups showed no increase. Total and free haptoglobin concentrations were significantly higher in the haptoglobin group than in the other two groups. Free haptoglobin concentrations were 0 after 5 days of storage in the control and ulinastatin groups. Polymorphonuclear leukocyte elastase concentrations increased with the increase in storage days without any differences among the three groups. Potassium concentration increased according to the storage and showed the highest value in the control group. CONCLUSIONS: Adding haptoglobin or ulinastatin to MAP-CRC was useful to suppress hemolysis during storage of the preparation. The polymorphonuclear leukocyte elastase might not be involved in the mechanisms of hemolysis in MAP-CRC stored for 25 days.

Blood Banks↗