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Biomedical subjects

K Omote

Publications and source records attributed to K Omote.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Differential effects of morphine and non-steroidal anti-inflammatory drugs on somatic and visceral pain in rats].

We studied the differential effects of morphine and non-steroidal anti-inflammatory drug (NSAIDs) on behavioral responses to tail-flick (TF) and colorectal distension (CD) in rats. Animals were randomly divided into three groups; morphine groups (4 mg.kg-1), flurbiprofen axetil groups (30 mg.kg-1) and aspirin DL-lysin groups (100 mg.kg-1). After determining control TF and CD values, animals received each analgesic intraperitoneally, and each procedure was repeated every 10 minutes for 30 or 40 minutes. NSAIDs produced a statistically significant increase in pain threshold for CD, but not for TF. In contrast, almost similar patterns of increase in pain thresholds for CD and TF were observed in morphine groups. The present study demonstrates that NSAIDs have a powerful antinociceptive effect on visceral pain evoked by CD.

Animals↗
PubMed1994

[Antagonism to neuromuscular effect of subcutaneous administration of pancuronium by neostigmine].

It has been reported that subcutaneous administration of pancuronium produces prolonged neuromuscular blockade. The purpose of this study was to evaluate the antagonistic effect of neostigmine on neuromuscular blockade following subcutaneous injection of pancuronium in anesthetized patients. Fourteen male patients aged 32-67 yr, weighing 50-58 kg, and scheduled for surgical operation lasting more than 6 hr were included in the study. None of the patients had paresis. Anesthesia was induced with thiamylal and SCC. Patients under N2O-oxygen-enflurane (1.0-1.5%) anesthesia, were divided into two groups (n = 7 in each group). Group A was given an intravenous bolus of pancuronium 6 mg. Group B received pancuronium 6 mg subcutaneously in the ankle. Train-of-four responses were evaluated every 12s by measuring the force of thumb adduction produced in response to supramaximal stimulation of the ulnar nerve at the wrist. When the train-of-four ratios recovered to approximately 0.2 in groups A and B, a mixture of neostigmine 1.0 mg and atropine 0.5 mg was administered. The onset of fade in train-of-four responses was significantly more rapid in group A (intravenous administration) than in group B (subcutaneous administration). Time intervals to maximum train-of-four depression from pancuronium administration in groups A and B averaged 2.6 and 125.4 min, respectively. No significant differences in the recovery times of the train-of-four ratios from 0.2 to 0.7 following neostigmine administration in groups A and B were demonstrated. None of the patients who received pancuronium subcutaneously showed recurarization following neostigmine administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Neoadjuvant chemotherapy for far-advanced gastric carcinoma].

Far-advanced gastric carcinoma of the stomach remains a lethal disease, showing a particularly poor prognosis in the patients with linitis plastica type. Considering the high potential for biological malignancies, we attempted preoperative induction (neoadjuvant) chemotherapy against far-advanced cancer associated with distant metastases. Anticancer drugs used in this study were FAM or sequential MTX/5-FU. Neoadjuvant chemotherapy was carried out on 24 patients prior to surgery. The response to chemotherapy showed shrinking of massive nodal involvement in 50% (5/10) and complete disappearance of malignant ascites in 87.5% (7/8). The morphological improvement of primary gastric lesions was obtained in 9 out of 24 cases (37.5%). In 15 cases (68.2%) total gastrectomy was done with extended lymph node dissection. In one of 9 cases showing marked improvement, no viable cancer cells were seen in whole stomach associated with multiple foci of granulomatous lesions of regional nodes after 3 cycles of MTX/5-FU. Disease-free survival of neoadjuvant group showed a significant prolongation of its median survival of 14 months, compared to that of 4-6 months in the surgery alone group. Our result leads to the conclusion that the patients whose tumor was effectively destroyed by neoadjuvant chemotherapy had a good prognosis.

Adult↗
PubMed1993

Potentiation of antinociceptive effects of morphine by calcium-channel blockers at the level of the spinal cord.

BACKGROUND: Opioids inhibit voltage-dependent calcium-channel conductance, which is essential for the nervous system to be able to signal a painful event. Accordingly, interference with calcium-channel conductance may enhance opioid analgesia. The current study was designed to investigate the effects of calcium-channel blocking drugs on the antinociception of morphine at the level of the spinal cord. METHODS: Rats were chronically implanted with catheters in the lumbar intrathecal space. Tail-flick test was used to assess thermal nociception. Intrathecally administered drugs were morphine, calcium-channel blockers (verapamil, diltiazem, and nicardipine), or a combination of morphine and calcium-channel blocker. RESULTS: Intrathecal administration of morphine produced a significant dose-dependent antinociception in the tail-flick test. In contrast, intrathecal administration of calcium-channel blockers, verapamil, diltiazem, and nicardipine, did not show any antinociception at the employed doses. However, when intrathecally administered calcium-channel blockers, verapamil (50 micrograms), diltiazem (100 micrograms), or nicardipine (20 micrograms), were combined with ineffective (0.25, 0.5, 1, or 2 micrograms) or moderately effective (5 micrograms) doses of intrathecally administered morphine, significant antinociception was produced. These interactions were synergistic. There were no significant changes in MAP or HR after the intrathecal administration of 200 micrograms verapamil or 2 micrograms morphine combined with 50 micrograms verapamil. CONCLUSIONS: The authors interpreted these results to indicate that calcium-channel blocking drugs synergistically potentiate the analgesic effects of morphine at the level of the spinal cord. Before these results can be translated into clinical use, however, adequate toxicity studies must be conducted to examine the effect of the perispinal administration of calcium-channel blocking drugs on spinal cord function.

Animals↗
PubMed1993

Cervico-thoracic epidural anaesthesia blunts pancuronium-induced increase in heart rate in humans.

This study was conducted to evaluate the effects of cervico-thoracic epidural anaesthesia upon pancuronium-induced tachycardia in surgical patients. In the control (no blockade) group (n = 8) and the lumbar epidural group (n = 8), pancuronium produced significant increases in heart rate (P < 0.01 and P < 0.01, respectively) and no significant changes in mean arterial pressure. In the cervico-thoracic epidural group (n = 8), no increase in heart rate and a significant decrease in mean arterial pressure were seen following pancuronium. The lack of an increase in heart rate following pancuronium with cervico-thoracic epidural anaesthesia might be due to cardiac sympathetic denervation. The authors concluded that tachycardia after pancuronium administration was attenuated by cervico-thoracic epidural anaesthesia in humans and that the pancuronium-induced tachycardia seemed to be a cardiac sympathomimetic effect.

Adult↗
PubMed1993

Norepinephrine prolongs tetracaine spinal anesthesia in surgical patients: a preliminary study.

We conducted a double-blinded examination of the effects of norepinephrine as a vasoconstrictor on the onset and duration of tetracaine spinal anesthesia in 80 surgical patients. The patients were randomly allocated to four groups (n = 20 in each group). Each patient received 10 mg of tetracaine in a volume of 2.0 mL which contained either 0 micrograms/mL, 5 micrograms/mL, 10 micrograms/mL, or 15 micrograms/mL of norepinephrine. The onset of spinal anesthesia was determined by the time to reach Th-10 level as well as by the time required to obtain the highest level of sensory analgesia. The time for two-segment regression and full-motor recovery were defined as the duration of spinal anesthesia. The time to reach Th-10, the highest analgesia level, and the time to obtain the highest analgesia level did not differ among the groups. Two-segment regression was prolonged significantly by 175%, 103%, and 106% as compared with the plain tetracaine group, in 5 micrograms/mL, 10 micrograms/mL, and 15 micrograms/mL of norepinephrine groups, respectively. Motor recovery also was extended significantly by 111%, 152%, and 121% as compared with the plain tetracaine group, in 5 micrograms/mL, 10 micrograms/mL, and 15 micrograms/mL of norepinephrine groups, respectively. There were no differences in the changes of arterial blood pressure and heart rate associated with the addition of norepinephrine among the groups. We conclude that norepinephrine provides a clinically meaningful prolongation of the duration of tetracaine spinal anesthesia.

Abdomen↗
PubMed1993

Central venous catheter migration to the popliteal artery during total cavopulmonary shunt.

Central venous catheter migration to the arterial system occurred due to the surgical procedure during total cavopulmonary shunt. The catheter seems to have crept into the portion of the vena cava that had been designated for clamping, because of the position for the surgery and the anatomic characteristics of the patient. The catheter migrated in the right popliteal artery and was removed immediately; however, it could enter the pulmonary arterial system and the other systemic arterial branches.

Adolescent↗
PubMed1992

Evaluation of basic procedures for adoptive immunotherapy for gastric cancer.

Peripheral blood lymphocytes (PBL) of gastric cancer patients in advanced stages showed lymphokine activated killer (LAK) activities comparable to those of healthy donors, suggesting potential applicability of LAK cells induced from PBL stimulated with recombinant interleukin-2 (rIL-2) in adoptive immunotherapy (AIT) for gastric cancer. In order to generate a large number of LAK cells from PBL, lymphocytes were cultured with both rIL-2 and phytohemagglutinin (PHA). In this culture, the numbers of cells increased to a greater extent than those in culture with rIL-2 alone but cytotoxic activity did not augment, thus suggesting that this procedure would not afford sufficient clinical effects. On the other hand, a large number of LAK cells with high anti-tumor activities were efficiently induced from spleen cells of the patients by culture of rIL-2; hence clinical usefulness of these LAK cells is anticipated. In regional lymph node lymphocytes (RLNL) cultured with rIL-2, the cytotoxic activities were lower than in those induced in PBL, and a characteristic increase of CD8 + CD11 + suppressor T cells was observed after incubation with rIL-2. Nevertheless, an increase of CD4 + 4B4 + helper inducer T cells was also observed in RLNL after the culture with rIL-2. Furthermore, high cytotoxic activities were induced in RLNL in some cases in which metastasis to the regional lymph nodes was not detected. When gastric cancer patients were pretreated with biological response modifiers (BRM), especially with Lentinan, LAK cells from PBL showed higher NK and LAK activities as compared with those of patients without BRM pretreatment.

Adult↗
PubMed1992

Epidural administration and analgesic spread: comparison of injection with catheters and needles.

This study was designed to investigate differences in epidural analgesic spread between catheter and needle injections in 48 patients with comparable physical characteristics. The spread of analgesia in the catheter injection group with a 0.24 ml.sec(-1) injection rate (n = 16) was 16.8 +/- 1.5 spinal segments and that in the needle injection group at the same injection rate (n = 16) was 12.5 +/- 1.8 spinal segments ( P < 0.01). Needle injection at the faster rate of 1.2 ml.sec(-1) (n = 16) produced a significantly greater spread of analgesia than with the 0.24 ml.sec(-1) rate through the needle (16.2 +/- 1.6 vs 12.5 +/- 1.8 spinal segments, P < 0.01). Thirteen of 16 patients receiving the fast needle injection complained of back compression or discomfort during the injection. The injection through an epidural catheter and the fast (1.2 ml.sec(-1)) injection through a needle produced extensive and equivalent epidural analgesic spread. However, because of patients discomfort with fast injection through the needle, the authors conclude that when using continuous epidural anesthesia, the initial injection of local anesthetic should be administered through the epidural catheter not the needle.

Journal Article↗
PubMed1992

Evaluation of cervical cord function using spinal evoked potentials from surface electrode.

Spinal evoked potentials from cervical skin surface (surface spinal evoked potentials) were measured to evaluate spinal cord function as a convenient method that precludes inserting electrodes into the epidural space, and results were compared with those of the former epidural recording method. Surface spinal evoked potentials were obtained from cervical skin surface over the C3, C5, and C7 spinous processes after median nerve stimulation in 18 normal subjects and 37 patients with a cervical lesion. In normal subjects, surface spinal evoked potentials consisted of three negative waves (N1, N2, N3). Abnormal N2 (80%) and abnormal N3 (100%) were observed in cervical myelopathy, and abnormal N2 was observed only in radiculopathy; this allows for differentiation between myelopathy and radiculopathy. Comparing preoperative and postoperative surface spinal evoked potentials, it was seen that improvement of clinical symptoms was proportional to that of surface spinal evoked potentials.

Adult↗
PubMed1992

Effects of nicardipine on the circulatory responses to tracheal intubation in normotensive and hypertensive patients.

This study was undertaken to examine the effects of nicardipine on circulatory responses to laryngoscopy and tracheal intubation in normotensive (n = 39) and hypertensive (n = 36) patients. Laryngoscopy and tracheal intubation were performed after induction of anaesthesia with thiamylal, followed by administration of intravenous saline or nicardipine 20 or 30 micrograms.kg-1 and suxamethonium. Blood pressure and heart rate were recorded, and rate-pressure product was calculated. Nicardipine 20 and 30 micrograms.kg-1 prevented the increase in mean arterial pressure after intubation in normotensive and hypertensive patients (p less than 0.01 compared with saline). The changes in heart rate after intubation were significantly greater in normotensive patients than in hypertensive patients when 20 or 30 micrograms.kg-1 of nicardipine was given (p less than 0.05 and p less than 0.01 respectively). Rate-pressure product increased significantly (p less than 0.01) after intubation in normotensive patients whether nicardipine was administered or not, but the increase was suppressed completely by nicardipine 20 or 30 micrograms.kg-1 in hypertensive patients. We conclude that nicardipine is effective in preventing the circulatory responses to laryngoscopy and tracheal intubation in hypertensive patients.

Adult↗
PubMed1992

[Interaction between opiates and neurotransmitters/neuromodulators in spinal analgesia].

Systematically administered morphine produces its antinociceptive effects through a mechanism involving synergism of the spinal and supraspinal opiate systems. Descending inhibitory monoaminergic pathways, including noradrenergic and serotonergic descending systems, participate in this production of antinociception. Recent studies indicate a synergistic interaction between opiates and adrenergic agonists in the spinal cord. The important consideration arising from the apparent synergy is that significant antinociceptive effects can be achieved with nonspecific doses of either agonist, which alone produces only minimal effects. Though synergy between opiates and adrenergic drugs were principally considered, there remains the possibility of spinal synergistic interactions of opiates and other neurotransmitters/neuromodulators. Since decreasing the effective dosage of analgesics may lessen or eliminate the complications of spinal opiates or other analgesics, these combined effects will be extremely useful for clinical pain management.

Analgesics, Opioid↗
PubMed1992

[Controversy between endoscopic and surgical treatment against early gastric and colorectal cancer].

Although endoscopic treatment against the patients with early cancer in gastrointestinal tract is an excellent method especially in high aged or poor risk patients, there still exists controversy about the indication for endoscopic treatment because of deeper invasion of the cancer or lymph node metastases. In order to clarify whether the patient has a possibility of nodal involvement or not, we made the clinicopathological analysis concerning 220 cases with early gastric cancers and 118 cases with colorectal cancers. Our retrospective analysis shows that endoscopic resection can be indicated for small polypoid cancer less than 10 mm in size, excluding IIa + IIc type. As to small depressed type, this procedure should be applied for IIc type which is well differentiated adenocarcinoma without ulcer formation (U1 (-)). Regarding early colorectal cancer there has been many discussion how to treat the patients with sm-cancer. Based on our analysis of 39 cases with sm-cancer, we led to the conclusion that the characteristics of sm-cancer with lymph node metastases are i) massive invasion into submucosal layer, ii) positive lymphatic permeation, or iii) "de novo" cancer. As a result, a decision of further surgery should be made even in small lesions less than 10 mm, taking the fact into consideration of the possibility of nodal involvement of sm-cancer.

Adult↗
PubMed1991

Delta receptor involvement in morphine suppression of noxiously evoked activity of spinal WDR neurons in cats.

Morphine has been considered to be primarily a mu opiate receptor agonist. The present study was designed to determine if opiate receptor subtypes in addition to mu contribute to morphine analgesia at the level of the spinal cord. Extracellular activity of single wide dynamic range (WDR) neurons in the feline lumbar spinal cord were studied. Intrathecal administration of DAGO (selective mu agonist) or DPDPE (selective delta agonist) suppressed the noxiously (51 degrees C radiant heat) evoked activity of WDR neurons. Pretreatment with spinal beta-FNA (selective mu antagonist) antagonized the suppressive effects of spinal DAGO, but not that of DPDPE. Two doses of spinal morphine (200 and 400 micrograms) suppressed the noxiously evoked activity of WDR neurons confirming our previous report. Following beta-FNA pretreatment, the suppressive effects of morphine were reduced, however, when ICI 174,864 (selective delta antagonist) was co-administered with morphine on the spinal cord of the animals pretreated by beta-FNA, there was an even greater reduction in the neuronal suppression by morphine. Intravenous ICI 174,864 also reversed the suppressive effects of morphine in beta-FNA pretreated animals. beta-FNA antagonism of spinal morphine is evidence of the well-known mu receptor-mediating antinociception. However, antagonism by ICI 174,864 of morphine suppression in beta-FNA-pretreated animals demonstrates that morphine is capable of suppressing noxiously evoked activity of WDR neurons as a result of an interaction with delta receptors in addition to mu receptors at the level of spinal cord.

Analgesia↗