Efficacy and Safety of Oxycodone Injection for Relieving Cancer Pain: A Study in Japan Consisting of Two Open Trials for Intravenous and Subcutaneous Administration

Pure oxycodone injection became increasingly necessary after oral oxycodone was launched in Japan in 2003. However, trials clarifying the efficacy and safety of injection are rare. Therefore, a multicenter open study on injection was designed and carried out in 2010, resulting in the launch of injection therapy in 2012. As published domestic case reports on efficacy already show widespread prescription, this study aimed to provide useful information for cancer pain relief in Japan and other countries. Our oxycodone injection study consisted of two trials, one of intravenous (S#9131) and the other of subcutaneous (S#9132) administration. The minimum required number of enrolled patients suffering cancer pain was determined to be 70 in S#9131 and 20 in S#9132. These studies had the same dose-titration protocol as the main endpoint, i.e., pain relief rate (PRR) defined as the rate of achieving adequate pain control (APC), as in prior oral oxycodone trials in Japan. In S#9131, PRR was 81.4% (95% confidence interval: 70.3-89.7%), therefore, the null hypothesis of PRR<70% was rejected using the binominal one-sided test (p=0.0217). In S#9132, PRR was 73.7% also surpassing 70%. Safety was also assessed in the same way as in prior trials. The majority of adverse effects were moderate or mild and recovered with no sequelae. As shown above, the injection was considered to be effective and safe in cancer pain treatment. The details of these trials, particularly the dose-titration protocol for achieving APC and route switching information, are expected to enhance injection convenience for prescribers.

How Do Hospital Palliative Care Teams Use the WHO Guidelines to Manage Unrelieved Cancer Pain? A 1-Year, Multicenter Audit in Japan

It has been reported that pain relief for patients with cancer is suboptimal in Japan. This has been mainly attributed to inadequate dissemination of the World Health Organization (WHO) guidelines for cancer pain management. To better understand this problem, we reviewed how 6 hospital palliative care teams (HPCTs) used the WHO guidelines for unrelieved pain in a 1-year audit that included 534 patients. The HPCT interventions were classified according to the contents of the WHO guidelines. In our study, HPCT interventions involved opioid prescriptions in >80% of referred patients, and “For the Individual” and “Attention to Detail” were the 2 most important principles. Our study indicates which parts of the WHO guidelines should be most heavily emphasized, when disseminating them in Japan.

Statins inhibit tumor progression via an enhancer of zeste homolog 2-mediated epigenetic alteration in colorectal cancer

While statin intake has been proven to reduce the risk of colorectal cancer (CRC), the mechanism of antitumor effects and clinical significance in survival benefits remain unclear. Statin-induced antiproliferative effects and its underlying mechanism were examined using six CRC cell lines. Statins except pravastatin showed antiproliferative effects (simvastatin ≥ fluvastatin > atorvastatin) even though both of simvastatin and pravastatin could activate mevalonate pathways, suggesting the statin-mediated antiproliferative effects depended on non-mevalonate pathway. Indeed, statin induced p27(KIP1) expression by downregulation of histone methyltransferase enhancer of zeste homolog 2 (EZH2), which acts as an epigenetic gene silencer. Additionally, the use of simvastatin plus classII histone deacetylase (HDAC) inhibitor (MC1568) induced further overexpression of p27(KIP1) by inhibiting HDAC5 induction originated from downregulated EZH2 in CRC cells and synergistically led to considerable antiproliferative effects. In the clinical setting, Statin intake (except pravastatin) displayed the downregulated EZH2 expression and inversely upregulated p27(KIP1) expression in the resected CRC by immunohistochemical staining and resulted in the significantly better prognoses both in overall survival (p = 0.02) and disease free survival (p < 0.01) compared to patients without statin intake. Statins may inhibit tumor progression via an EZH2-mediated epigenetic alteration, which results in survival benefits after resected CRC. Furthermore, statin plus classII HDAC inhibitor could be a novel anticancer therapy by their synergistic effects in CRC.

Role of dopamine D2 and D3 receptors in mediating the U-50,488H discriminative cue: comparison with methamphetamine and cocaine

Substitutions of the dopamine D(2) or D(3) receptor agonists for the discriminative stimulus effect induced by U-50,488H, methamphetamine (METH) and cocaine in rats were examined. The D(2) receptor agonist R-propylnorapomorphine [(-)-NPA] failed to substitute for U-50,488H cue, while the D(3) receptor-preferred agonist (+/-)-7-hydroxy-dipropylaminotetralin hydrobromide (7-OH-DPAT) produced dose-related increases in drug-appropriate responding up to 0.03 mg/kg, which fully substituted. At doses greater than 0.03 mg/kg of 7-OH-DPAT, there was a dose-dependent decrease in the percentage of responses on the U-50,488H-appropriate lever. Furthermore (-)-NPA and 7-OH-DPAT at high doses substituted for the discriminative stimulus effect induced by both METH and cocaine, indicating that 7-OH-DPAT at high doses may interact with D(2) receptors. These results suggest that the stimulation of D(2) receptor may be critical for the production of the discriminative stimulus effect induced by METH and cocaine, whereas the stimulation of D(3) receptor may contribute to the production of the U-50,488H cue.

Enhancement of glutamatergic transmission in the cingulate cortex in response to mild noxious stimuli under a neuropathic pain-like state

Pain is evoked by noxious body stimulation or through negative emotional events and memories. There are several caveats to the simple proposition that pain and emotion are linked in the cingulate cortex (CG). In this study, we investigated whether mild noxious heat stimuli could affect the neuronal activity in the CG of rats with sciatic nerve ligation. We produced a partial sciatic nerve injury by tying a tight ligature in rats. Seven days after sciatic nerve ligation, rats received mild noxious heat stimuli. Mild noxious heat stimuli produced flinching behaviors in sciatic nerve-ligated rats, but not sham-operated rats. In addition, the mild noxious heat stimuli caused a significant increase in the release of glutamate in the CG of nerve-ligated rats compared with that of sham-operated rats. Furthermore, phosphorylated-NR1-positive cells in this area significantly increased after mild noxious heat stimuli under a neuropathic pain. Under this condition, there were no significant changes in the levels of immediate-early genes such as c-fos, c-jun, JunB, and Fra1 in the CG between nerve-ligated and sham-operated rats. However, mild noxious heat stimuli under a neuropathic pain-like state produced a marked increase in the phosphorylated-c-jun (p-c-jun) immunoreactivity, which is commonly used to map neurons in the brain that can be activated after N-methyl-D-aspartate receptor activation. These findings raise the possibility that mild noxious heat stimuli under a peripheral nerve injury may increase the release of glutamate and promote its related postneuronal activity in the CG.

[Efficacy and safety of compound oxycodone injection for cancer pain relief-a multicenter survey of prescriptions]

Oral oxycodone has been available since 2003 in Japan. Oxycodone consumption is increasing along with the decrease in morphine consumption. Although this drug currently has a central role in cancer pain treatment, at this time pure oxycodone injection has not yet been available in Japan. As an alternative, we can subcutaneously administer a compound oxycodone injection (Pavinal) containing a small amount of hydrocotarnine. Since few clinical reports on efficacy and safety of the compound oxycodone injection have been published in Japan, we conducted a retrospective multicenter survey with structured sheets. Monthly survey data regarding the compound prescriptions for cancer pain control have been collected from 3 cancer hospitals. Finally, sixty adult patients were analyzed with the following results. (1) The adverse effects caused by the prior opioids improved in more than half of the patients, and worsened in none. (2) Dose escalation of the drug was achieved through subcutaneous administration(the mean was 1.6 times), and resulted in pain relief with tolerable adverse effects in more than 80% of patients. (3) Adverse effects occurred in 13% of patients, but more than 80% of the episodes were mild in severity. Conversely, we found no adverse effects becoming sequelae, failure and/or fatal in severity. (4) Subcutaneous administrations with the drug were available in long-term(mean 15.4 days, maximum 53 days), including home palliative care use (1.7%). No toxicities due to accumulation were observed. (5) The conversion ratio from oral oxycodone to compound oxycodone injection was 0.82+/-0.20, and the domestic and international reports are basically consistent with our result. So we speculate that the compound can be regarded as a pure oxycodone injection using subcutaneous administration. While further studies are needed, our study indicated that compound oxycodone injection has efficacy and safety in cancer pain treatment. Especially in switching opioids and/or their routes of administration to enhance the analgesic potency along with reducing the adverse effect, we conclude that prescribing this drug can be a convenient alternative.

Baclofen as an adjuvant analgesic for cancer pain

PURPOSE

Baclofen is a g-aminobutyric acid receptor agonist commonly used for managing many types of neuropathic pain. The effect of baclofen on cancer pain has not previously been studied. This retrospective study evaluated the efficacy of baclofen in patients with cancer pain.

METHODS

We reviewed the medical records of all patients given baclofen orally as an analgesic for cancer at 5 institutions.

RESULT

Twenty-five patients received 10 to 40 mg of baclofen for cancer pain relief. Twenty patients have undergone neuropathic pain such as paroxysmal or lancing, sharp, or like an electric shock. Baclofen was effective in 21 of 25 patients and significantly reduced Numeric Rating Scale (pain score, 0-10; P < .0001). Nine patients reported mild adverse events: none of these 9 patients had to discontinue baclofen due to adverse events.

CONCLUSION

Our findings suggest that baclofen may be a useful adjuvant analgesic in the treatment of cancer pain.

Epidural ropivacaine infusion for the treatment of pain following axillary muscle-sparing thoracotomy: a dose-evaluation study

PURPOSE

We aimed to investigate the optimal dose of continuous epidural ropivacaine for effective analgesia with minimal side effects after axillary muscle-sparing thoracotomy.

METHODS

Sixty patients undergoing thoracic surgery via the axillary approach were studied. Patients were given continuous epidural ropivacaine at 6 (group R-6), 9 (group R-9), 12 (group R-12) or 18 mg x h(-1) (group R-18) in a randomized double-blinded fashion after surgery. All of the patients received nonsteroidal anti-inflammatory drugs (NSAIDs) every 6 h for 24 h postoperatively. Pain intensity was assessed under three conditions (at rest, on moving, and while coughing), at 4, 8, 16, 24, and 48 h after surgery, and the extent of sensory block was evaluated at the same time points. The ability of a patient to walk unaided was assessed at 24 and 48 h after surgery.

RESULTS

Pain intensity at rest and coughing was significantly higher in group R-6 than in the other groups at 16 h after surgery. Pain intensity during moving was significantly greater in group R-6 than in groups R-12 and R-18 at 16 h after surgery. Group R-18 exhibited a significantly greater extent of sensory block than the other groups. The number of patients who were not able to walk unaided 24 h after surgery was significantly greater in group R-18. There were no significant differences in the incidences of side effects among the groups.

CONCLUSION

Our results showed that epidural analgesia using ropivacaine, at 12 mg x h(-1), provided the best analgesia with few side effects.

[Validity of recommended minimum dose of prior morphine to initiate transdermal fentanyl patch in prescribing information - multicenter survey of on prescriptions by palliative care specialists in Japan]

For initiating the minimum-size (0.25 microg/hour) transdermal fentanyl patch (TDF), 45 mg a day of oral morphine is the recommended minimum dose (RMD) in Japan according to the prescribing information. However, little is known about the validity of the RMD, and we can presume there are many cases where clinicians are inclined to initiate the minimum-size TDF at the early stage contrary to the RMD due to the high morbidity rate of digestive system cancer in Japan. In order to verify the validity of the RMD, we collected 71 retrospective cases where the minimum-size TDF was initiated against the restriction of RMD. The prior morphine (or equivalent doses of other opioids) was prescribed by palliative care specialists at 5 facilities which belong to Symptom Control Research Group (SCORE-G). Then, the side effects and pain control from the 1st to the 4th day were analyzed. The mean age of subjects was 68, and the main reason for initiating TDF therapy was gastrointestinal symptoms (63.4%). The frequency of side effects such as somnolence, nausea, vomiting and constipation did not show a significant correlation with the prior opioid dose.However,severe dyspnea and respiration depression were documented in two patients, and the above rate was three times higher than the nationwide result of the same side effects (0.9 8%). According to the Numeric Rating Scale (from 0: no pain to 10: the worst pain), the pain intensity decreased from 6.6 on the 1st day to 2.8 on the 2nd day, 3.3 on the 3rd day, and 2.9 (p < 0.001) on the 4th day. We conclude that, although introducing the minimum-size TDF against the RMD served to decrease the pain intensity,it raised the side effects on the respiratory system even when prescribed by palliative care specialists. Therefore,the RMD regulation is valid for general practitioners from a medical safety standpoint.

Evaluation of Allodynia and Pain Associated With Postherpetic Neuralgia Using Current Perception Threshold Testing

OBJECTIVES

Postherpetic neuralgia has various clinical features, and the implicated pathophysiologic mechanisms are controversial. This study was carried out to clarify the roles of peripheral sensory nerves in the production of allodynia and ongoing pain. Current perception threshold (CPT) testing was used to evaluate the sensory function.

METHODS

The intensities of ongoing pain and dynamic allodynia were assessed using a numeric rating scale (0-10). Assessment of sensory nerve function was performed by a series of 2,000-, 250-, and 5-Hz stimuli using CPT testing. These measurements were made in ipsilateral and contralateral area.

RESULTS

CPTs at all frequencies in the ipsilateral area were significantly higher than those in the contralateral area. There were significant and inverse correlations between the intensity of allodynia and CPTs at all frequencies. No correlation was found between the intensity of ongoing pain and CPTs at any frequency. There was no correlation between the intensity of ongoing pain and the intensity of dynamic allodynia.

CONCLUSIONS

The intensity of dynamic allodynia in postherpetic neuralgia correlates with the preserved functions of Abeta, Adelta, and C fibers. In contrast, the intensity of ongoing pain does not correlate with either the preserved function of C fibers or the intensity of dynamic allodynia. Therefore, it is suggested that postherpetic neuralgia might be a pain syndrome including both peripheral and central mechanisms.

Cardioprotective effects of KB-R7943, a novel inhibitor of Na+/Ca2+ exchanger, on stunned myocardium in anesthetized dogs

PURPOSE

The present study was carried out to determine the cardioprotective effects of KB-R7943 (KBR), a selective inhibitor of the reverse mode of Na+/Ca2+ exchanger (NCX), on stunned myocardium in anesthetized dogs.

METHODS

The dogs were allocated to one of three groups (n = 7 for each group), and received drug vehicle (group C), low-dose KBR (5 mg x kg(-1) i.v.) (group L) or high-dose KBR (10 mg x kg(-1) i.v.) (group H) at 15 min before left anterior descending coronary artery (LAD) occlusion. Stunned myocardium was produced by 15-min occlusion of LAD and 90-min reperfusion in all dogs. Regional myocardial contractility was evaluated with segment shortening (%SS).

RESULTS

Recovery of %SS at 90 min after reperfusion was significantly improved in group H (70.8% +/- 3.9% of baseline), whereas the recovery was poor in groups C and L (34.3% +/- 2.8% and 36.4% +/- 5.4% of baseline, respectively). Regional myocardial blood flow showed no significant difference among groups. KBR had no effect on coronary or systemic hemodynamics.

CONCLUSION

The results show that preischemic administration of high-dose KBR markedly improves myocardial contractile dysfunction after ischemia-reperfusion in anesthetized dogs, indicating that KBR protects myocardium against the ischemia-reperfusion injury in vivo.

Negative inotropic action of propofol is enhanced in the acute ischemic myocardium of dogs

PURPOSE

We investigated the effects of propofol on contractility and oxygen balance in acute ischemic myocardium and compared them with those of normal myocardium using a coronary microembolization model in dogs.

METHODS

In open-chest dogs, the left anterior descending coronary artery (LAD) was perfused through an extracorporeal bypass from the carotid artery. Regional myocardial contractility and myocardial oxygen balance were evaluated along with segment shortening (%SS), regional myocardial oxygen consumption (MVO2), and lactate extraction ratio (LER) of the area perfused by the LAD. Acute ischemia was produced by repeated injection of microspheres into the LAD-perfused area until %SS decreased by 50% of baseline.

RESULTS

In normal myocardium, intracoronary infusion of propofol at doses of 1.2 and 2.4 mg x kg(-1) x h(-1) caused slight decreases in %SS to 83% +/- 8% and 80% +/- 10%, respectively. In ischemic myocardium, propofol caused greater decreases in %SS (59% +/- 18% and 35% +/- 20%, respectively). The changes in MVO2 after propofol infusion generally paralleled the changes in %SS, but LER was not changed in either ischemic or normal myocardium.

CONCLUSION

Propofol causes a greater decrease in the contractility of acute ischemic myocardium as compared with normal myocardium in which myocardial oxygen imbalance is not involved as a mechanism.

The Effects of Dexmedetomidine on Left Ventricular Function During Hypoxia and Reoxygenation in Isolated Rat Hearts

Hypoxia resulting from apnea in patients with sleep apnea is an important factor in heart disease. We designed the present study to determine whether dexmedetomidine (DEX) has a direct protective effect against hypoxia-reoxygenation-induced left ventricular dysfunction without systemic hemodynamic and humoral effects. Isolated rat hearts were exposed to 60-min hypoxia followed by 30-min reoxygenation with 0, 10, or 100 nM DEX prehypoxia administration (n = 7 each group). In a second experiment (n = 7), 100 nM DEX was administered posthypoxia. In a third experiment (n = 7 each group), an alpha 2 antagonist, yohimbine was given with and without 100 nM DEX prehypoxia administration. DEX prehypoxia, but not posthypoxia, administration significantly improved the recovery of left ventricular developed pressure after reoxygenation (0, 10, 100 nM DEX prehypoxia or 100 nM DEX posthypoxia values were 53 +/- 6, 64 +/- 9, 78 +/- 13, or 62 +/- 12 mm Hg [mean +/- sd]) and reversed by yohimbine, 58 +/- 8 mm Hg, respectively. We conclude that DEX exerts the direct protective effect on the left ventricular dysfunction caused by hypoxia-reoxygenation through mainly alpha 2-adrenergic stimulation before and during the hypoxic period.

Quantitative and selective evaluation of differential sensory nerve block after transdermal lidocaine

We evaluated the effect of transdermal lidocaine on differential sensory nerve block in 15 healthy volunteers. Lidocaine 10% gel was applied topically to a forearm and covered with a plastic film. Three types of sensory nerve fibers (Abeta, Adelta, and C fibers) were evaluated with a series of 2000-, 250-, and 5-Hz stimuli using current perception threshold (CPT) testing. Sensations of touch, pinprick, cold, and warmth were also measured. These measurements were made before the topical lidocaine (baseline), 60 min after the draping (T0), and at 1-h intervals until 5 h after T0 (T1 to T5). A significant increase in CPT compared with baseline was observed until T2 at 5 Hz and T4 at 250 Hz, whereas the increase in CPT at 2000 Hz continued throughout the study period. All subjects experienced the disappearance of pinprick and cold sensations, whereas touch and warmth sensations were detectable during the study period. We conclude that when lidocaine is applied transdermally, the sensitivity of nerves to local anesthetics is proportional to the axon diameters. However, pinprick and cold sensation are affected more strongly than other sensations at receptor sites.

IMPLICATIONS

We evaluated the effect of transdermal lidocaine on differential sensory nerve block in healthy volunteers. Our results show that the sensitivity of nerves to local anesthetics is proportional to the axon diameter.

Multiple Sclerosis With Severe Pain and Allodynia Alleviated by Oral Ketamine

The objective of this study is to determine the effect of oral ketamine on pain and allodynia associated with multiple sclerosis. A 60-year-old woman with multiple sclerosis was referred to our clinic because of severe pain and allodynia. Oral ketamine was started at a dose of 20 mg once a day and increased to twice a day. Oral ketamine was effective in the treatment of the pain and allodynia associated with multiple sclerosis.

The Interaction of MCI-154, a Calcium Sensitizer, and Isoflurane on Systemic and Coronary Hemodynamics in Chronically Instrumented Dogs

We conducted this study to determine the interaction of MCI-154, 6-[4-(4'-pyridylamino)phenyl]-4,5-dihydro-3(2H)-pyridazinone hydrochloride, a calcium sensitizer, and isoflurane on myocardial contractility as well as systemic and coronary hemodynamics in chronically instrumented dogs after pharmacological autonomic nervous system activity blockade. MCI-154 increased heart rate and left ventricular function with no change in rate pressure product, pressure work index, and coronary blood flow, with a decrease in coronary vascular resistance (CVR) in the conscious state. Isoflurane decreased heart rate and left ventricular function, with a decrease in rate pressure product and pressure work index. Isoflurane also decreased CVR, but not coronary blood flow. The cardiovascular actions of MCI-154 during isoflurane anesthesia were qualitatively similar to those observed in the conscious state. In contrast to the finding in the conscious state, MCI-154 reversed the decrease in cardiac output and preload recruitable stroke work caused by isoflurane, but these are not significantly different from the effects of isoflurane alone. These results indicate that MCI-154 increases myocardial contractility and decreases CVR without changing calculated myocardial oxygen consumption during both the conscious state and isoflurane anesthesia.

IMPLICATIONS

MCI-154, a calcium sensitizer, restores the myocardial contractility depressed by isoflurane and enhances the coronary vasodilating effect of isoflurane in chronically instrumented dogs.

A comparative evaluation of transcutaneous and end-tidal measurements of CO2 in thoracic anesthesia

We performed this study to assess the accuracy of transcutaneous CO(2) (PTCCO(2)) monitoring compared with end-tidal CO(2) (PETCO(2)) in thoracic anesthesia. Twenty-six patients undergoing pneumonectomy with thoracotomy for which a long period of one-lung ventilation (OLV) was required were studied. The lungs were mechanically ventilated in the lateral decubitus position. PTCCO(2), PETCO(2), and arterial CO(2) (PaCO(2)) were simultaneously measured during two-lung ventilation (TLV) and during OLV at intervals of 15 min. All patients completed the study protocol. Bland-Altman analysis revealed a bias of -0.4 mm Hg with a precision of +/-2.5 mm Hg during OLV and 1.4 mm Hg with +/-4.3 mm Hg during TLV when PTCCO(2) and PaCO(2) were compared and revealed a bias of -5.8 mm Hg with a precision of +/-4.1 mm Hg during OLV and -7.1 mm Hg with +/-4.6 mm Hg during TLV when PETCO(2) and PaCO(2) were compared. We conclude that PTCCO(2) monitoring is accurate for evaluating CO(2) levels during thoracic anesthesia.

Hemodynamic interactions of propofol and dantrolene in chronically instrumented dogs

The hemodynamic interaction of dantrolene, a specific drug for malignant hyperthermia, and propofol which appears to be safe in malignant hyperthermia-susceptible patients, has not been investigated. We performed this study to examine the hemodynamic actions of dantrolene at a therapeutic dose during propofol anesthesia. Ten dogs were chronically instrumented for the measurements of systemic and coronary hemodynamics. The dogs were assigned to receive propofol with vehicle or dantrolene in a random manner on separate experimental days. Propofol significantly decreased mean arterial blood pressure, left ventricular systolic and end-diastolic pressure, the maximal rate of increase in left ventricular pressure, and left ventricular regional segment shortening. Coronary blood flow (CBF) was unchanged but coronary vascular resistance (CVR) decreased. Dantrolene reversed the decrease in mean arterial blood pressure and left ventricular systolic pressure caused by propofol, and significantly increased heart rate. However, left ventricular end-diastolic pressure, cardiac output, maximal rate of increase in left ventricular pressure, and segment shortening were unchanged. CBF was significantly increased with a decrease in CVR. These results suggest that dantrolene reverses the hypotensive action produced by propofol and causes an increase in CBF with a decrease in CVR, but does not significantly change the negative inotropic effects. Thus, dantrolene exerts favorable hemodynamic effects during propofol anesthesia.

IMPLICATIONS

Our study suggests that dantrolene reverses the hypotensive action produced by propofol and causes an increase in coronary blood flow with a decrease in coronary vascular resistance, but does not significantly change the negative inotropic effects.

Germinal center-associated nuclear protein (GANP) has a phosphorylation-dependent DNA-primase activity that is up-regulated in germinal center regions

Antigen stimulation induces a rapid proliferation of B cells for expansion of specific B cell clones and their further differentiation into antibody-producing cells in germinal centers of T-dependent antigen-immunized mice. Previously, we identified a 210-kDa germinal center-associated nuclear protein (GANP) that is up-regulated selectively in germinal centers and carries an MCM-binding domain in the carboxyl-terminal side. In addition, here, we found a region (from 414 to 550 aa) in GANP molecule that is slightly similar to the known DNA-primase component p49. The recombinant GANP fragment covering this region synthesizes RNA primers for extension by DNA polymerase I with single-stranded DNA templates in vitro. GANP DNA-primase activity is controlled by phosphorylation at Ser(502) that is induced by CD40-mediated signaling in vitro and in the germinal center B cells stimulated with antigen in vivo. Overexpression of ganp cDNA in Daudi B cells caused the increased DNA synthesis more than the levels of the mock-transfectants. These evidences suggested that the novel DNA-primase GANP is involved in regulation of cell proliferation of antigen-driven B cells in germinal centers.

Sevoflurane protects stunned myocardium through activation of mitochondrial ATP-sensitive potassium channels

We sought to determine the hemodynamic and cardioprotective effects of sevoflurane in canine stunned myocardium. Forty-nine dogs were allocated to one of seven groups (n = 7 for each). In six separate groups, dogs received vehicle, glibenclamide (a nonselective adenosine triphosphate-dependent potassium [K(ATP)] channel antagonist) (0.3 mg/kg IV) or 5-hydroxydecanoic acid (a mitochondrial K(ATP) channel antagonist) (5 mg/kg IV) in the presence or absence of 1 minimum alveolar concentration (1 MAC) sevoflurane. In an additional group, dogs received 1 MAC sevoflurane with hemodynamic correction. Regional myocardial contractility was evaluated with segment shortening. Measurements were made before and during 15-min ischemia and 90-min reperfusion. Recovery of segment shortening 90 min after reperfusion was significantly improved in the dogs anesthetized with sevoflurane either with or without hemodynamic correction (70.1 +/- 4.2 and 75.9 +/- 3.1% of baseline, respectively), whereas the recovery was poor in control and glibenclamide or 5-hydroxydecanoic acid pretreated dogs (33.3 +/- 4.3, 33.8 +/- 6.8, and 45.0 +/- 5.5% of baseline, respectively). Regional myocardial perfusion showed no significant difference among groups. The results indicate that sevoflurane has a cardioprotective effect mediated through activation of mitochondrial K(ATP) channels and independent of coronary blood flow or reduction in cardiac work.

IMPLICATIONS

Sevoflurane exerts a cardioprotective effect that is mediated via activation of adenosine triphosphate-sensitive potassium channels in ischemic canine hearts.

Interaction of isoflurane and cromakalim, a KATP channel opener, on coronary and systemic haemodynamics in chronically instrumented dogs

BACKGROUND

Although isoflurane has been shown to cause coronary and systemic vasodilation through KATP channel activation, the interaction of KATP channel openers and isoflurane has not been fully investigated. The present study was carried out to determine the haemodynamic actions of cromakalim, a KATP channel opener, under the conscious state and during isoflurane anaesthesia in chronically instrumented dogs.

METHODS

Fourteen dogs were chronically instrumented to measure systemic and coronary haemodynamics. Each dog was randomly assigned to receive doses of either cromakalim, 4 and 10 microg x kg(-1) i.v., or isoflurane, 2.1% end-tidal (1.5 MAC), plus cromakalim, 4 and 10 microg x kg(-1) i.v.

RESULTS

Cromakalim dose-relatedly decreased mean arterial pressure and systemic vascular resistance and increased coronary blood flow in both conscious and anaesthetized states. With isoflurane, the duration of effects of cromakalim were prolonged. Isoflurane exerted an additive effect on the increase in coronary blood flow induced by a low-dose cromakalim, whereas it did not influence the effect of a high-dose cromakalim. The maximum rate of increase in left ventricular pressure and segment shortening were increased by cromakalim in the conscious state but unchanged during isoflurane anaesthesia.

CONCLUSION

The results suggest that the coronary vasodilating effects of isoflurane and cromakalim are basically additive until cromakalim exerts the maximal effect, and that the action of cromakalim on the coronary vasculature is prolonged by isoflurane.

A novel nuclear phosphoprotein, GANP, is up-regulated in centrocytes of the germinal center and associated with MCM3, a protein essential for DNA replication

Antigen (Ag) immunization induces formation of the germinal center (GC), with large, rapidly proliferating centroblasts in the dark zone, and small, nondividing centrocytes in the light zone. We identified a novel nuclear protein, GANP, that is up-regulated in centrocytes. We found that GANP was up-regulated in GC B cells of Peyer's patches in normal mice and in spleens from Ag-immunized mice. GANP-positive cells appeared in the light zone of the GC, with coexpression of the peanut agglutinin (PNA) (PNA)-positive B220-positive phenotype. The expression of GANP was strikingly correlated with GC formation because Bcl6-deficient mice did not show the up-regulation of GANP. GANP-positive cells were mostly surrounded by follicular dendritic cells. Stimulation with anti-micro and anti-CD40 induced up-regulation of ganp messenger RNA as well as GANP protein in B220-positive B cells in vitro. GANP is a 210-kd protein localized in both the cytoplasm and nuclei, with a homologous region to Map80 that is associated with MCM3, a protein essential for DNA replication. Remarkably, GANP is associated with MCM3 in B cells and MCM3 is also up-regulated in the GC area. These results suggest that the up-regulation of GANP might participate in the development of Ag-driven B cells in GCs through its interaction with MCM3.

[Monitored anesthesia care for a patient with malignant pheochromocytoma]

Monitored anesthesia care (MAC) is being increasingly used in the 1990s for a wide variety of diagnostic and therapeutic procedures. The primary objective in providing MAC is to ensure patients' comfort and safety, whether in the operating room or in other places. We experienced MAC for a patient with pheochromocytoma. A 63-year-old man with hepatic metastasis of malignant pheochromocytoma, received transcatheter arterial embolization (TAE) in the angiographic room. Hypertension and ventricular arrhythmia occurred during the hepatic arterial embolization. However, we successfully controlled the hemodynamic changes using phentolamine and propranolol under the close monitoring. He showed an uneventful recovery during postoperative period except for mild hypotension on the third day which needed temporary norepinephrine infusion.

Comparative analysis of systemic and coronary hemodynamics during sevoflurane- and isoflurane-induced hypotension in dogs

We studied the effects of sevoflurane on myocardial contractility and systemic and coronary hemodynamics, as compared with the effects of isoflurane in dogs under the same cardiac work conditions. Sixteen mongrel dogs were anesthetized with alpha-chloralose. Heart was paced at 100 beats/min after producing a complete atrioventricular (A-V) block. Controlled hypotension to a mean arterial pressure (MAP) of 60 mm Hg was induced and maintained by inhalation of either anesthetic, lasting for 60 min. Measurements were made at baseline, 15 min (T1), and 60 min (T2) after starting hypotension, and 30 min after discontinuing equihypotension (T3). Although left ventricular systolic segment shortening (%SS) decreased approximately 20% in both groups, cardiac output (CO) decreased only in sevoflurane during equihypotension (-27.6% at T2). Sevoflurane decreased the coronary blood flow (CBF; -34.8% at T2) with no significant change of coronary vascular resistance (CVR), whereas isoflurane produced a significant decrease in CVR resulting in no change of CBF despite of decreased coronary perfusion pressure (-37.4% at T2). These systemic and coronary vascular effects were continued even at T3. In conclusion, myocardial depressant effects were comparable between sevoflurane and isoflurane. Both systemic and coronary vasodilatory effects of isoflurane are greater than those of sevoflurane.

Malignant pheochromocytoma with multiple hepatic metastases treated by chemotherapy and transcatheter arterial embolization

A 62-year-old Japanese male developed multiple hepatic metastases two years after resection of pheochromocytoma of the right adrenal gland. Transcatheter arterial embolization (TAE) was performed for the purpose of the treatment of hepatic metastases resistant to 27 cycles of combined chemotherapy consisting of cyclophosphamide, vincristine, and dacarbazine. After TAE, the hepatic metastatic lesions decreased in size and hypertension passed its crisis. The present case suggests the utility of TAE for multiple hepatic metastases under careful blood pressure monitoring.

[Endoscopic resection of the thoracic sympathetic trunk for the treatment of frequent syncopal attack of idiopathic long QT syndrome]

A 22 year old man was diagnosed as having Jervell and Lange-Nielsen syndrome (JLNS), which includes a prolonged QTc, congenital neural deafness, and syncopal attacks or sudden death. In spite of medication with beta blocker, syncopal attack increased in frequency since his sister suddenly had died of JLNS. Because left stellate ganglion block improved the QTc dispersion, left cardiac sympathectomy was scheduled under the video-assisted thoracic surgery. After the premedication with midazolam, anesthesia was induced with thiamylal, and maintained with nitrous oxide, sevoflurane, and fentanyl. Serious arrhythmias were not observed throughout the perioperative period. Sympathetic trunk was successfully resected from the top of 1st ganglion to the bottom of 4th ganglion of left thoracic sympathetic trunk. Horner's sign did not appear after the surgery. Although the shortening of QTc was not significant, QTc dispersion during exercise was improved, and syncopal attack was not observed until 6 months after the surgery.

Carbachol, norepinephrine, and hypocapnia stimulate phosphatidylinositol turnover in rat tracheal slices

BACKGROUND

The intracellular mechanisms involved in the alpha-adrenoceptor- or hyperventilation-induced bronchoconstriction remain unknown. Because there is a direct relationship between phosphatidylinositol (PI) metabolism and airway smooth muscle contraction induced by muscarinic agonists, the authors examined the effects of carbachol (CCh), norepinephrine (NE), and hypocapnia on PI turnover in the airway smooth muscle.

METHODS

Rat tracheal slices were incubated in Krebs-Henseleit solution containing LiCl and [3H]myo-inositol in the presence of NE, CCh, or neither. The PCO2 in the solution was 36 +/- 3 mmHg (normocapnia), 19 +/- 2 mmHg (moderate hypocapnia), or 5 +/- 2 mmHg (severe hypocapnia), respectively. [3H]inositol monophosphate (IP1) formed was counted with a liquid scintillation counter.

RESULTS

Basal IP1 formed was greater at severe hypocapnia than at normocapnia. Norepinephrine- and CCh-induced IP1 formation were also greater at hypocapnia than at normocapnia.

CONCLUSIONS

These results indicate that CCh, NE, and hypocapnia stimulate PI turnover in the airway smooth muscle, which would cause bronchoconstriction, and hypocapnia also augments NE- and CCh-induced PI turnover, which could cause worsening of exercise-induced asthma and vagotonic asthma, respectively.

[Interaction of cardiovascular effect of calcium channel blocking drugs and those of inhalation anesthetics in humans]

The hemodynamics in the patients undergoing craniotomy was studied to evaluate the interaction of cardiovascular effects of calcium blocking drugs (nicardipine NCR or diltiazem DL) and those of inhalation anesthetics (0.6% isoflurane Iso or 0.9% sevoflurane Sevo). (Group I = NCR alone, Group II = NCR+Iso, Group III = NCR+Sevo, Group IV = DL alone, Group V = DL+Iso, Group VI = DL+Sevo) Anesthesia was maintained with neuroleptanesthesia (N2O 60%). A 30% reduction in systolic blood pressure was achieved and this was maintained for 60 minutes in each groups. The following effects were observed during induced hypotension. 1) Heart rate increased in the group I and II, but decreased in the group IV, V and VI. 2) Cardiac output increased in the group I and II, but significantly decreased in the group VI. 3) Systemic vascular resistance and left ventricular stroke work decreased in all the groups. 4) Pulmonary vascular resistance decreased slightly in all the groups. 5) Cardiac arrhythmias were observed in 4 cases of the group IV and VI. These results suggest that the presence of Iso or Sevo at low concentrations does not have a marked effect on the pharmacologic action of NCR or DL in humans.

[Differential lung ventilatory management during bronchoplasty]

We compared two methods of respiratory managements during bronchoplasty surgery. In one lung ventilation group (OLV-G), 10 patients were ventilated with Broncho-cath tube or Univent tube. On another 10 patients, ventilation was performed with Univent tube following insertion of bronchial blocker into main bronchus of dependent lung. Dependent lung was then ventilated using high frequency jet ventilation (HFJV) through bronchial blocker superimposed with low tidal volume IPPV (selective HFJV, S-HFJV-G). Oxygenation index (O.I.) of S-HFJV-G was significantly higher than that of OLV-G when bronchus was open. These phenomena might have occurred through prevention of pulmonary blood flow shift to the non-dependent lung when S-HFJV was used.

[Investigation of limulus test during and after cardiopulmonary bypass. Part II. Effect of washing of the bypass circuit]

Previously we reported the presence of Limulus positive substance (LPS) in blood and urine for several days following cardiopulmonary bypass (CPB), and foreign particles in the primining fluids. The purpose of this study was to evaluate the effect of washing of the CPB circuit on appearance of LPS and to define the nature of it. Semi-quantitative Limulus test was performed in patients using washed CPB circuit (n = 54) and without washing (n = 41). LPS in the blood were negative in all patients before CPB. LPSs in the priming fluids did not disappear after washing, however the amounts of it in the blood were significantly lower than those without washing. Especially at second postoperative day. Limulus test were positive in 10% of patients with washed CPB circuit and 60% of those without it (p less than 0.01), and all the urine samples of patients with washed CPB circuit were negative to Limulus test at 1st postoperative day. The number of foreign particles decreased in parallel with the smaller pore size of the filter. Since reactions of Pregell to ethylene oxide gas, ethylene chlorohydrin and ethylene glycol were negative, ethylene oxides did not seem to be the LPS. These results indicate the superiority of employment of washed CPB circuit with micropore filter. However, further exploration is still mandatory to elucidate the LPSs.

[Investigation of Limulus test during and after cardiopulmonary bypass--analysis of Limulus positive substance and particles in the cardiopulmonary bypass circuit]

Patients undergoing heart surgery with cardiopulmonary bypass (CPB) frequently have positive Limulus test without any remarkable signs of endotoxemia. CPB circuit could be one of the possible causes of this phenomenon, but the exact mechanism has not been studied. Accordingly, a prospective study was made in 41 patients undergoing heart surgery with CPB. Limulus test were performed on the samples of priming fluids of CPB including the plasma and urine of those patients during and after surgery. Besides the Limulus test, the CPB fluids were analysed by the false positive test. Microscopic examinations were carried out on the priming fluids before and after using a 40 microns filter during recirculation without washing the CPB circuit and the fluid from a 4 microns filter been washed by 2000 ml of Martose-10 in order to find out the presence of any foreign particles in the CPB circuit. The size and the number of particles were measured by coulter counter. The studies revealed the following facts, 1) Limulus test; most of the samples from priming fluids (31/35), plasma circulating the CPB (36/36), urine during CPB (22/25) and plasma (34/35) and urine (21/30) just after the surgery revealed positive. However, only 4 samples from plasma at 3POD and 2 samples from urine at 2POD revealed positive, 2) false positive test of the samples from priming fluids was negative meaning the Limulus positive substances are not endotoxin, 3) under microscopic analysis and coulter counter, there were about 40 particles over 50 microns per ml of priming fluids before washing the CPB circuit.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of nitroglycerin ointment on cardiovascular functions in hypertensive patients during emergence from anesthesia]

The present study was designed to investigate the effect of nitroglycerin (TNG) ointment to attenuate the cardiovascular response of hypertensive patients during emergence from anesthesia compared with the effects of TNG infusion and nifedipine instillation in the nose. In addition, plasma TNG concentration was measured in the TNG ointment group and TNG infusion group. TNG 30 mg in ointment reduced the arterial pressure during extubation without producing hypotension and tachycardia. There was no significant difference in plasma TNG concentration between TNG ointment group and TNG infusion group each receiving 0.3 micrograms.kg-1.min-1. The study suggests that TNG ointment is useful for regulation of arterial pressure in hypertensive patients during emergence from anesthesia.