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Biomedical subjects

T Kumazawa

Publications and source records attributed to T Kumazawa.

At least 163 records · Page 9Linked to original sources

[Anesthetic management with continuous epidural buprenorphine of a patient with dystrophia myotonica].

We report an anesthetic management of a 45 year-old female patient with dystrophia myotonica who was scheduled for abdominal total hysterectomy. The patient was diagnosed as dystrophia myotonica 8 years ago. Epidural catheterization was performed through Th12-L1 interspace and spinal anesthesia was performed through L2-3 interspace using 3.3 ml of 0.5% bupivacaine. Adequate block below Th5 level was obtained. The intraoperative course of anesthesia was uneventful. Moreover, the continuous epidural administration of buprenorphine gave a satisfactory postoperative pain relief and no respiratory depression was observed. Spinal or epidural anesthesia seems to be effective and safe for the patient with dystrophia myotonica.

Anesthesia, Epidural↗

[Anesthetic management of laparoscopic ovarian cystectomy in a 2-year-old child].

We have experienced the anesthetic management of laparoscopic ovarian cystectomy in a 2-year-old child. The patient was anesthetized with isoflurane and manually ventilated to keep PaCO2 at 30 mmHg prior to the carbon dioxide insufflation of the peritoneal cavity. Two minutes after the abdomen was distended, end-tidal CO2 began to increase and after 10 minutes PaCO2 was 50 mmHg. We had to increase tidal volume and respiratory rate, although airway pressure was 30 cmH2O. We should be careful because children who undergo pneumoperitoneum become hypercapnic easily during general anesthesia.

Anesthesia, General↗

Effects of intravenous anaesthetics on function and metabolism in the isolated rat heart-lung preparation.

The influence of several intravenous anaesthetics on the heart was assessed using the isolated rat heart-lung preparation. Each group received 10(-3)mol litre-1 and 10(-4)mol liter-1 of ketamine, 6 micrograms ml-1 and 60 micrograms ml-1 of midazolam, 6 micrograms ml-1 and 60 micrograms ml-1 of diazepam or 0.6 micrograms ml-1 and 6 micrograms ml-1 of flunitrazepam. Systolic blood pressure in rats receiving high doses of midazolam, diazepam and ketamine were higher than that in the control group. Heart rate in rats receiving high doses of ketamine and diazepam were lower than that in the control group. However, there were no significant changes in cardiac output among the groups. Maximum rate of left ventricular tension development in rats receiving high doses of midazolam and diazepam increased significantly in comparison with that in the control group. There were no significant changes in myocardial high energy phosphates among the groups. None of the intravenous anaesthetics, even in doses which were 100 times greater than therapeutic doses, showed any depressant effects in this preparation. Moreover, it is surprising that midazolam and diazepam produced direct increases in myocardial contractility. These results suggest that the cardiodepressant effects of intravenous anaesthetics may be due to their effects on the central nervous system.

Adenosine Diphosphate↗

Involvement of EP3 subtype of prostaglandin E receptors in PGE2-induced enhancement of the bradykinin response of nociceptors.

Prostaglandin E2 augments bradykinin-induced discharges of polymodal receptors as studied in vitro preparations. The antagonist and agonists for three subtypes of EP receptors were used to determine which subtype is involved in this phenomenon. The agonist for EP3 (M&B28767) simulated the PGE2-induced effect but not for EP2 (butaprost). The antagonist for EP1 (AH6809) did not suppress the effect. These findings indicate the involvement of the EP3 receptor subtype in the effect.

Alprostadil↗

Adrenergic excitation of cutaneous nociceptors in chronically inflamed rats.

To probe the mechanisms underlying sympathetically maintained pain, the effects of lumbar sympathetic chain stimulation (SS) and close arterial injection of norepinephrine (NE) on cutaneous nociceptor activities were studied in adjuvant inflamed rats. Two to 28 weeks after adjuvant treatment, single nerve recordings of polymodal receptors from the saphenous nerve were performed. In treated rats but not in controls, SS and NE were excitatory in 35-40% of units. Yohimbine and CH-38083 blocked NE excitation, but prazosin did not. Our data show that chronic inflammation initiates circumstances in which alpha 2-adrenoceptor-mediated sympathetic activity excites some nociceptors.

Adjuvants, Immunologic↗

Augmenting effects of cyclic AMP on the heat response of canine testicular polymodal receptors.

It has long been thought that the augmenting effects of E series prostaglandins (PG) are mediated by cyclic AMP (cAMP). In clarifying the validity of this hypothesis, we studied the effects of increases in intracellular cAMP on the heat response of testicular polymodal receptors. Recordings were obtained from testis-spermatic nerve preparations excised from dogs anesthetized with pentobarbital (30 mg/kg, i.v.). Induction of increases in intracellular cAMP by either forskolin, an adenylyl cyclase activator, or a mixture of dibutyryl cAMP (10(-4) M) and 3-isobutyl-1-methyl xanthine (10(-4) M) significantly and reversibly augmented the heat response. These results support the notion that cAMP is involved in the augmenting effect of PG E2 on the heat response of nociceptors.

1-Methyl-3-isobutylxanthine↗

Prostaglandin E2-induced sensitization of the heat response of canine visceral polymodal receptors in vitro.

The sensitizing effect of prostaglandin (PG) E2 on the heat response of testicular polymodal receptors was studied in vitro by recording single polymodal receptor activities from the testis-spermatic nerve preparations excised from deeply anesthetized dogs. PG E2 at 10(-7) M had no significant influence on the heat response. PG E2 at 10(-6) and 10(-5) M did not induce substantial increases in discharge rates, yet it significantly augmented the heat response. The concentration necessary for augmenting the heat response is thus 100 times greater than that (10(-8) M) previously reported for bradykinin [Naunyn-Schmiedebergs Arch. Pharmacol., 344 (1991) 368-376].

Animals↗

Spinal termination patterns of canine identified A-delta and C spermatic polymodal receptors traced by intracellular labeling with Phaseolus vulgaris-leucoagglutinin.

The spinal projection patterns of spermatic polymodal receptors were studied by intracellular labeling of functionally identified canine dorsal root ganglion (DRG) neurons with Phaseolus vulgaris-leucoagglutinin (PHA-L). The processes of 2 C-fiber and 1 A-delta-fiber spermatic polymodal receptor neurons were labeled well enough to trace their central terminations. The labeled C-fiber DRG neurons were of medium size (mean diameter 36.8 and 40.7 microns). On entering the spinal cord, axons of the C-polyclonal receptors divided into rostral and caudal main branches that extended over 3 spinal segments (20 and 25 mm, respectively), and issued a total of 16 and 15 collaterals, respectively. The majority of collaterals ran in or along the lateral surface, but both neurons had 1 or 2 collaterals or terminal branches running through the middle, or along the medial surface of the dorsal horn. Terminal swellings and en passant enlargements were observed mainly in laminae I, V, and VII. Some C-fiber terminations appeared in lamina II and the adjacent lateral column. The A-delta polymodal receptor had a termination pattern similar to that of the C-fiber units with the exception of a shorter distance over which its 13 identified collaterals were issued (10 mm), and continuation of the rostral main branch into Lissauer's tract (traced for 3.6 mm) after all branches appeared. Two terminal branches were found running just above the central canal in another A-delta neuron in which termination could be only partially traced.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

Failure to verify high levels of pyrroloquinoline quinone in eggs and skim milk.

The levels of pyrroloquinoline quinone (PQQ) in eggs, skim milk and milk was re-examined by the use of gas chromatography/mass spectrometry. PQQ was extracted from the samples, after addition of [U-13C]PQQ as internal standard, with n-butanol and Sep-Pak C18 cartridges. After derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ, respectively, by selected ion monitoring. PQQ could be detected in eggs, skim milk and milk, but their levels were very low (e.g., egg yolk: 7.0 ng/ml; skim milk: 2.5 ng/g dry weight). Our data for eggs and skim milk are far below those measured by the redox cycling method of Gallop's group.

Animals↗

Influence of LAK cells on expression of HLA-DR antigen on laryngeal carcinoma cell line in new culture systems.

We demonstrated the enhancement of HLA-DR antigen expression on cultured laryngeal carcinoma cells (Hep 2) by in vitro cultivation with LAK cells using flow cytometric and immunohistological analysis. For in vitro cultivation of tumor cells with LAK cells, we used newly developed experimental systems (the Transwell double-dish system and experimental three-dimensional tumors). In flow cytometric analysis, expression of HLA-DR antigen on tumor cells was compared before and after co-cultivation with LAK cells. When tumor cells were cultured separately with LAK cells in a Transwell Petri dish and the expression of HLA-DR antigen on tumor cells was analyzed by flow cytometry, the expression of HLA-DR antigen on tumor cells was increased in a dose-dependent manner related to the number of LAK cells used. Furthermore, when anti-interferon-gamma monoclonal antibody was added to the experimental system, enhancement of HLA-DR antigen expression was blocked. These findings were consistent with immunohistological studies, in which experimental three-dimensional Hep 2 cell tumors were established in double-layered agar with/without being co-cultivated with LAK cells. The expression of HLA-DR antigen in this system was significantly increased when compared to such expression before cultivation with LAK cells. These findings suggested that the culture systems employed in this study could be a possible model for examining solid tumor in vivo biological responses. This enhanced expression of HLA-DR antigen may also represent one of the multi-factorial responses seen with adoptive LAK cell immunotherapy for solid tumors.

Antigens, Surface↗

A new infrared tympanic thermometer in surgery and anesthesia.

We have evaluated a new infrared tympanic thermometer, IT-10, as an intraoperative temperature monitor in patients with or without open abdominal surgery. It determines temperature by measuring infrared radiation given off by a warm object. Temperatures measured with this device were closely correlated with those measured with rectal and bladder thermometries. We conclude that this new tympanic thermometer is safe, convenient, accurate, and easily usable in the clinical situation.

Journal Article↗

Effects of pyrroloquinoline quinone (PQQ) and PQQ-oxazole on DNA synthesis of cultured human fibroblasts.

The effects of pyrroloquinoline quinone (PQQ) and PQQ-oxazole (PQQ-glycine adduct) on DNA synthesis were examined using cultured human fibroblasts. Confluent fibroblasts were cultured in serum-free Dulbecco's modified Eagle's media, and various concentrations of PQQ and PQQ-oxazole were added to the media. After incubation for 24 h, [3H]thymidine was added to the media as an indicator for DNA synthesis of the cells. The thymidine incorporation into the cells was significantly enhanced even in the presence of very low concentrations of PQQ (0.003-0.03 microM); it remained significantly enhanced, up to 30 microM PQQ. However, the incorporation remarkably decreased at 750-1500 microM of PQQ. In contrast to the results for PQQ, DNA synthesis was not stimulated by addition of 0.003-3 microM PQQ-oxazole, but it was slightly enhanced at concentrations 15-750 microM. In morphological examination of the cultured human fibroblasts, cell density was increased by addition of 0.003-30 microM PQQ when compared with that of the control, supporting the above biochemical data. However, there were no distinct differences in morphological effect between PQQ and PQQ-oxazole.

Adult↗

Autoradiographic localization of somatostatin mRNA in the adult rat lower brainstem: observation by the double illumination technique.

Using in situ hybridization histochemistry and observation with a double (dark and bright) illumination apparatus, the precise localization of preprosomatostatin mRNA was studied in the adult rat lower brainstem and cerebellum. It has previously been hard to localize the somatostatin precursor gene in the adult rat brainstem, because the level of expression is low or undetectable in some brain areas in adulthood, in contrast to the high levels in the neonatal period. The present study in adult rats showed the clear localization of this mRNA in the same areas where it is found in the perinatal period. The results showed that somatostatin neurons in such areas continue the minimal production of the precursor gene even at the adult stage.

Animals↗

The taste system of the channel catfish: from biophysics to behavior.

Catfish, described as 'swimming tongues', are unique experimental models for studies of taste reception because of the extensive distribution of taste buds over their external body surface and within their oropharyngeal cavity. Both the extraordinary numbers of taste buds and their high sensitivity to amino acids have made it possible to perform in the same species: biochemical and biophysical studies of stimulus recognition and signal transduction; electrophysiological recordings of taste activity from receptor cells, afferent nerve fibers and CNS relays; and behavioral studies of taste-controlled food search, biting and mastication. The close correspondence of results obtained with these diverse experimental approaches has provided critical information concerning vertebrate gustation.

Amino Acids↗

Positive- and negative-ion mass spectrometry of diphenylmethane antihistaminics and their analogues and rapid clean-up of them from biological samples.

Positive-ion electron impact (PIEI), positive-ion chemical ionization (PICI) and negative-ion chemical ionization (NICI) mass spectra are presented for 15 compounds of diphenylmethane antihistaminics and their analogues, and each fragmentation pathway was analyzed. In the PIEI mode, molecular peaks were very small or missing for most compounds. Peaks at m/z 58, due to a dimethylaminomethyl group liberated, constituted base peaks in five compounds. Peaks at m/z 165 and/or 167, due to diaromatic rings plus a methyl group, appeared in most compounds. In the PICI mode, peaks due to M+H and M+C2H5 appeared in all compounds. Peaks due to diaromatic rings plus a methyl or ethyl group constituted base peaks in five compounds, which had an ether bond in their structures. In the NICI mode, anions at m/z M-H appeared in most compounds. Peaks at m/z 35 were observed for compounds having a chlorine group in their structures. Detection limits for total ion monitoring of these compounds were 20-50 ng on column in the PIEI mode, 100-200 ng in the PICI mode and 500-1000 ng in the NICI mode. A rapid and simple clean-up procedure of these drugs with use of Sep-Pak C18 cartridges is also presented. The drugs could be detected by gas chromatography with DB-1 and DB-17 capillary columns with satisfactory separation from impurities in their underivatized forms. The recovery of the drugs, which had been added to whole blood and urine, was more than 60% except for meclizine.

Benzhydryl Compounds↗