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Biomedical subjects

K Suwa

Publications and source records attributed to K Suwa.

At least 37 records · Page 2Linked to original sources
PubMed1998

The blood-gas partition coefficient of xenon may be lower than generally accepted.

The blood-gas partition coefficients of xenon, reported more than 25 yr ago in the literature, vary considerably from 0.13 to 0.20. Consequently, we have determined this variable by directly injecting xenon-saturated blood into a gas chromatograph-mass spectrometer. This technique yielded a blood-gas partition coefficient for xenon of 0.115 (95% confidence interval 0.107-0.123). The solubility in water measured identically was 0.096, consistent with the reported value of 0.085. These data and a detailed review of the literature strongly suggest that the blood-gas partition coefficient of xenon may be lower than the generally accepted value of 0.14.

Anesthetics, Inhalation↗
PubMed1998

Panipenem-betamipron and decreases in serum valproic acid concentration.

Serum concentrations of valproic acid (VPA) were reduced to 0% to 40% of the original levels by concomitant use with panipenem-betamipron (PAM-BP) in three patients. The serum VPA level began to decrease 2 days after the administration of PAPM-BP, and it began to increase within 24 hours of the last dose. The rapid change in the serum VPA level suggests the existence of unique and as yet unknown mechanisms of interaction between VPA and PAPM-BP. Epileptic seizures developed in two of the three patients during PAPM-BP use, which signaled the dangers of PAPM-BP administration to patients concomitantly administered VPA. PAPM-BP should not be used in patients administered VPA.

Adult↗
PubMed1998

In vitro pharmacologic profile of YM158, a new dual antagonist for LTD4 and TXA2 receptors.

YM158 (3-[(4-tert-butylthiazol-2-yl)methoxy]-5'-[3-(4-chlorobenzenesu lfonyl ) propyl]-2'-(1H-tetrazol-5-ylmethoxy)benzanilide monosodium salt monohydrate) antagonizes leukotriene (LT) D4 and thromboxane (TX) A2 receptors. Functional assays in vitro showed that YM158 exhibits competitive dual antagonism of LTD4 and TXA2 receptor-mediated contraction of isolated guinea pig tracheae, with pA2 values of about 8.87 and 8.81, respectively. Its antagonistic activity for the LTD4 receptor was approximately 6.5 times less potent than that of montelukast, and that for the TXA2 receptor was 2.5 times more potent than that of seratrodast. YM158 also inhibited PGD2- and PGF2alpha-induced tracheal contractions. YM158 showed no antagonism against LTC4-, histamine- or carbachol-induced contractions of guinea pig tracheae. Furthermore, YM158 antagonized the stable TXA2 analog U46619-induced aggregation of both guinea pig and human platelets and inhibited the LTD4-induced contraction of guinea pig ileum. From these results, YM158 appears to be a novel, selective dual antagonist for both LTD4 and TXA2 receptors.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1997

Genome organization of human 48-kDa oligosaccharyltransferase (DDOST).

The enzyme oligosaccharyltransferase (dolichyl-diphosphooligosaccharide-protein glycosyltransferase; EC 2. 4.1.119) (DDOST) catalyzes the transfer of a high-mannose oligosaccharide (GlcNac2Man9Glc3) from a dolichol-linked oligosaccharide donor (dolichol-P-GlcNac2Man9Glc3) onto the asparagine acceptor site within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains across the membrane of the endoplasmic reticulum. We isolated mouse and human DDOST cDNAs from retinoic acid-treated mouse P19 EC cells and human NT-2 cells, respectively. DDOST mRNA is expressed intensely in heart and pancreas, but at lower levels in brain. Here we show that the human DDOST 48-kDa subunit gene (HGMW-approved symbol DDOST) is organized into 11 exons expanding about 9 kb. This DDOST subunit gene is localized on chromosome 1p36.1 by fluorescence in situ hybridization analysis.

Amino Acid Sequence↗
PubMed1997

Effects of occupational use of vibrating tools in the autonomic, central and peripheral nervous system.

OBJECTIVES: The objective of this study was to clarify the autonomic, central and peripheral nervous effects of vibrating-tool operation. METHODS: The ECG R-R interval variability (CVRR), including the C-CVHF, C-CVLF (two component CVs of the CVRR reflecting parasympathetic and sympathetic activities, respectively) and the power spectral densities (PSDHF and PSDLF) after autoregressive analysis, short-latency somatosensory evoked potentials (SSEP), distribution of nerve conduction velocities (DCV), and median and radial nerve conduction velocities (NCVs) were measured in 17 vibrating-tool operators and the same number of age-matched control subjects. Some of the operators complained of white finger even in summer as soon as they arrived at the cold workplace. DESIGN: The significance of the differences in neurophysiological data between the exposed and unexposed groups and the associations between these data in the former were investigated. RESULTS: The CVRR, C-CVHF and PSDHF were significantly lower in the vibrating-tool operators than in the matched controls. The N9-N13 interpeak latency of the SSEP, i.e., conduction time of the cervico-spinobulbar pathway, in the operators was significantly prolonged as compared with the controls; the faster velocities of the DCV and the NCVs were significantly slowed in the operators. The N9-N13 interpeak latency in the operators was significantly correlated with the C-CVHF. CONCLUSION: Complex stressors of local vibration, cold, noise and heavy work, seem to affect the cervico-spinobulbar, parasympathetic and peripheral nerve functions. Also, parasympathetic hypofunction may imply a consequence in brainstem pathology induced by cold exposure in addition to vibration.

Adult↗
PubMed1997

Vagal and sympathetic denervation in the development of oleic acid-induced pulmonary edema.

This study investigates the effects of autonomic denervation on extravascular lung water, pulmonary hemodynamics, the filtration coefficient of pulmonary vasculature and oxygenation in the development of pulmonary edema. Thirty seven dogs were divided into seven groups. No experimental treatment was conducted in group Nc (n = 4, sham operation) or group Nv (n = 6, bilateral vagotomy) during a 3 h observation period. In the following groups, oleic acid (0.06 ml/kg) was injected into a central vein to induce pulmonary edema: group OAc (n = 6, intact innervation); group OAv (n = 6, bilateral vagotomy); group OAa (n = 6, alpha-blockade by phentolamine); group OAs (n = 6, alpha- and beta-blockade by sympathectomy); and group OAvs (n = 3, vagosympathectomy). The results showed that in the dogs with normal lungs, bilateral vagotomy per se did not cause lung injury during 3 h of observation. However, in oleic acid pulmonary edema, vagotomy significantly deteriorated pulmonary edema by increasing pulmonary intravascular pressures; Alpha- or alpha- and beta- sympathetic inhibition deteriorated pulmonary edema by increasing pulmonary microvascular permeability. The severity of oleic acid-induced pulmonary edema was same in the dogs with vagosympathectomy as in the dogs with intact innervation. These results suggest the inhibition of vagal or sympathetic innervation will aggravate pulmonary edema in the dog.

Animals↗
PubMed1997

Beneficial effects of the prone position on the incidence of barotrauma in oleic acid-induced lung injury under continuous positive pressure ventilation.

BACKGROUND: Factors that contribute to ventilator-induced barotrauma are not well defined. This study investigates the effects of posture on ventilator-induced barotrauma, as well as arterial oxygenation. METHODS: Twelve dogs with oleic acid lung injury, lying in the prone position (n = 6) and right lateral position (n = 6), were mechanically ventilated with continuous positive pressure ventilation for 24 hours. The incidence of pneumothorax and arterial oxygenation were investigated in each position. RESULTS: All animals lying in the lateral position developed pneumothorax in the nondependent thorax, while only one animal in the prone position developed pneumothorax in the left thorax (P < 0.05). Postmortem examination revealed that in the lateral group, the nondependent lung consisted of large areas of emphysematous regions and neutrophil infiltration regions, while the dependent lung was composed of extensive atelectasis and neutrophil infiltration. Lung ruptures occurred in the nondependent lung at the regions of either emphysematous change or severe neutrophil infiltration. In the prone group, in contrast, both lungs were inflated fairly homogeneously with only small areas of atelectatic and emphysematous changes. In the dog in whom pneumothorax developed, lung ruptures were limited to the regions of severe neutrophil infiltration in the left lung. No animal in either group had a peak airway pressure more than 20 cmH2O. The peak airway pressures were 17.5 +/- 1.3 cmH2O in the lateral group and 16.6 +/- 2.1 cmH2O in the prone group (P > 0.05). Tidal volume was comparable between the lateral group (13 +/- 2 ml/kg) and the prone group (12 +/- 1 ml/kg) before pneumothorax occurred (P > 0.05). Arterial oxygenation was much better in the prone group than in the lateral group during the experiment (P < 0.05). CONCLUSION: It was concluded that in lung injury dogs, the prone position has beneficial effects on the incidence of ventilator-induced barotrauma and arterial oxygenation when compared with the lateral position. Ventilator-induced barotrauma may occur at lower airway pressure.

Animals↗
PubMed1997

Partial seizures associated with cisplatin administration: a case report.

A 49-year-old man was treated with cisplatin and pirarubicin for tongue cancer. After the second course of chemotherapy, partial seizures including transient motor aphasia, tonic finger movement, and loss of consciousness were observed. The EEG showed frequent diffuse (multiple) spike and slow wave discharges. Following the administration of carbamazepine and diazepam, no seizures occurred and no paroxysmal discharges were observed or EEGs. We conclude that carbamazepine and diazepam administration was effective.

Antibiotics, Antineoplastic↗
PubMed1997

[Low preoperative PaO2 in patients with ovarian and endometrial cancer].

We investigated preoperative PaO2 and changes of PaO2/FIO2 (P/F) during the operation in 40 patients with gynecologic malignancies (ovarian cancer (O group) = 14 cases, endometrial cancer (E group) = 14 cases, cervical cancer (C group) = 12 cases). Preoperative chest X-ray and respiratory function test of our patients were within normal ranges (% VC > or = 80, % FEV 1.0 > or = 70). There were no differences among 3 groups in age, height, weight, % VC, or % FEV 1.0. Preoperative PaO2 values in the O group and E group were significantly lower than the normal value (100--age/4). Preoperative PaO2 and P/F values in the O group were significantly lower in comparison with those in the C group. We suggest, therefore, that it is necessary to measure preoperative PaO2 in patients with ovarian and endometrial cancer.

Adult↗
PubMed1997

[Effects of cardiac output on PETCO2 and PaCO2 during combined inhalational-epidural anesthesia].

We investigated the effects of cardiac output on PETCO2 in anesthetized patients. We studied 8 adult patients undergoing long-lasting lower abdominal surgery. Anesthesia was maintained with epidural combined with inhalational anesthesia. The minute ventilation volume was kept constant at 10 ml.kg-1 x 10 cycles.min-1. PETCO2, PaCO2, and cardiac index, (CI) by thermodilution method were measured simultaneously. PaCO2 was corrected for body temperature for comparison with PETCO2. Approximate value of alveolar dead space to tidal volume ratio was calculated as VD/ VTalv = (PaCO2-PETCO2)/PaCO2. The measurements were repeated every 10 to 20 minutes under the steady body temperature. One hundred and six sets of data were obtained from these patients. PETCO2 as well as PaCO2 correlated positively with CI, while VD/VTalv did not correlate with CI. PETCO2 correlated positively with PaCO2, while it did not correlate with VD/VTa1v. When examined in individual patients, PETCO2 correlated positively with CI in 7 patients. PaCO2 correlated positively with CI in 6 patients, while VD/VTa1v correlated negatively with CI only in 2 patients, in whom CI showed a large fluctuation. PaCO2 correlated positively with PETCO2 in 8 patient, while VD/VTa1v correlated negatively with PETCO2 only in 1 patient. By multiple regression analysis, VD/VTa1v change accounted for only 20.0 +/- 15.3% of PETCO2 change, while PACO2 or PaCO2 change accounted for 79.3 +/- 16.7%. Decreased CI was associated with a decrease in oxygen uptake (VO2), and PaCO2 correlated positively with VO2. Decreased CI was also associated with an increase in VA/Q, and PaCO2 correlated negatively with VA/Q. Thus, PETCO2 decreased with decreasing cardiac output. A decrease in PACO2 explained the decrease in PETCO2 better than an increase in VD/VT did. Decreased cardiac output caused hypocapnia through decreased CO2 production and/or increased ventilation to perfusion ratio i.e. relative hyperventilation.

Adult↗
PubMed1997

Primary structure of porcine spleen ribonuclease: sequence homology.

The primary structure of porcine spleen RNase (RNase Psp1) was investigated as a mean of assessing the structure-function relationship of base non-specific ribonucleases of animal origin. N-terminal analysis of RNase Psp1 yielded three N-terminal sequences. These peptides were separated by gel-filtration on Superdex 75HR, after reduction and S-carboxymethylation of RNase Psp1. Determination of the amino-acid sequence of these peptides indicated that the RNase Psp1 preparation consisted of three peptides having 20 (RCM RNase Psp1 pep1), 15 (RCM RNase Psp1 pep2), and 164 (RCM RNase Psp1 pro) amino-acid residues, respectively. It possessed two unique segments containing most of the active site amino-acid residues of the RNases of the RNase T2 family. The alignment of these three peptides in RNase Psp1 was determined by comparison with the other enzymes in the RNase T2 family. The overall results showed that RCM RNase Psp1 pep1 and RCM RNase Psp1 pep2 are derived from the N-terminal and C-terminal regions of RNase Psp1, respectively, probably by processing by some protease. The molecular mass of the protein moiety of RNase Psp1 was 23235 Da.

Amino Acid Sequence↗
PubMed1997

Guided tissue regeneration (GTR) versus cementum-impregnated gelatine membrane (CGM) techniques: a histologic comparison of relative effectiveness in promoting periodontal attachment.

Some prior reports have suggested that guided tissue regeneration (GTR) procedures achieve only partial regeneration and induces the ankylosis rather than true attachment. Accordingly, others have developed an alternative procedure employing gelatine membrane compounded with bovine cementum particles (CGM) which has proven effective in stimulating a more physiologic form of attachment. This study was undertaken to perform a direct comparison of histological results when CGM and GTR membrane were used at comparable sites in the same monkey. Three monkeys with no periodontal disease were used. Following flap surgery, recession type defects were created on the buccal side of the maxillary lateral incisors and second premolars, and the cementum was removed from the root surface at an area corresponding to the bone crest. The right and left lateral incisors and second premolars were covered with CGM and GTR membrane, respectively. The GTR membranes were removed after 4 weeks. At 6 wks, the animals were sacrificed, and specimens were prepared for histological examination. More coronally placed true new attachment was observed following application of CGM to the planed root surfaces. Application of the GTR membrane resulted in formation of bone-like cementum and ankylosis, whereas CGM established true periodontal regeneration.

Animals↗
PubMed1996

Pancuronium increases pulmonary arterial pressure in lung injury.

We studied 25 mongrel dogs who were anaesthetized and their lungs ventilated for investigation of the effects of pancuronium on pulmonary arterial pressure (PAP) in the normal lung, in oleic acid-induced lung injury and in lung injury with hypoxaemia. In the normal lung, PAP was not affected by pancuronium. During lung injury, however, PAP was increased from 21.5 (SD 2.8) to 24.6 (4.2) mm Hg (P < 0.01) and from 22.0 (4.2) to 27.0 (5.8) mm Hg (P < 0.01) after pancuronium 0.08 mg kg-1 and 0.16 mg kg-1, respectively, and from 26.0 (2.9) to 37.1 (3.1) mm Hg after pancuronium 0.16 mg kg-1 when hypoxaemia was present (P < 0.01). The increase in PAP induced by pancuronium was associated with increases in cardiac output and pulmonary vascular resistance. Pretreatment with phentolamine attenuated the pancuronium-induced increase in PAP. The increase in PAP induced by pancuronium was also reduced by vagotomy. If these results in dogs are relevant clinically, then pancuronium should be avoided as a neuromuscular blocker in lung injury.

Animals↗
PubMed1996

Biosynthesis of the acetylenic compounds in cultured cells of Asparagus officinalis from D- and 13C-labelled phenylalanines.

Studies on the biosynthetic pathway of acetylenic compounds, 4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]phenol and its related compounds, in cultured cells of Asparagus officinalis L. (Liliaceae) revealed that all of the 17 carbon atoms in their skeletons are supplied by phenylalanine. It is also concluded that p-substituted phenylacetylenic moieties (the C6-C2 unit) in these compounds are derived from C6-C3 shikimate pathway metabolites via phenylalanine. As a working hypothesis concerning the C6-O-C3 unit formation, a spirotetrahydrofuran type intermediate is predicted.

Acetylene↗
PubMed1996

[Lateralization in dissociated vertical deviation with flash visual evoked potentials].

Lateralization, suggesting misrouting of optic nerve fibers in albinism, was examined by the flash visual evoked potentials (flash VEP) test in dissociated vertical deviation (DVD). Eighteen cases of DVD were studied and compared with 5 cases of X-recessive ocular albinism and 4 normal controls. Full-field monocular and binocular stimulation was employed with electroencepharograph electrodes on O1 and O2 (10/20 system), and the latency of P100 was statistically analysed with two-way analysis of variance. The difference in the P100 latency between contralateral and ipsilateral stimulation was significant (p < 0.05) in albinism, but not in DVD and normal controls. Therefore, DVD is probably not associated with misrouting of optic nerve fibers.

Adolescent↗