Site-specific mutagenesis of the human interleukin-1 beta gene: the role of arginine residue at the N-terminal region

Using the expression system for site-specific mutagenesis in Escherichia coli, we have made deletion mutants at the N-terminal or C-terminal region of human interleukin-1 beta (IL-1 beta) consisting of 153 amino acids. The truncated mutants showed that at least 147 amino acids (numbers 4-150) in IL-1 beta are necessary for the exertion of biological activity. When we changed the arginine at the 4th position (Arg4) in IL-1 beta to other specific amino acids, there was a marked difference in the relative extent of biological and receptor binding activities among the mutants. The order of the mutants was Arg4 = Lys4 greater than Gln4 greater than Gly4 = des-Arg4 greater than Asp4. Our results demonstrate that the arginine residue at the 4th position in IL-1 beta is important, but not essential, for IL-1 beta to exhibit its biological and receptor binding activities, and the positive charge at this site plays a key role for IL-1 beta to exert the activities.

Effects of sevoflurane on cardiovascular dynamics, coronary circulation and myocardial metabolism in dogs

The effects of 2.5% and 5% of sevoflurane anesthesia on hemodynamics and myocardial metabolism were studied in pentobarbital-pancuronium anesthetized dogs. The interaction between nicardipine and 2.5% sevoflurane was also examined. Sevoflurane produced dose-dependent ( P << 0.05 to P << 0.01) decreases in systolic arterial pressure (SAP), heart rate (HR), cardiac index (CI), left ventricular minute work index (LVMWI), maximum rate of rise of left ventricular pressure (LV dP/dt), the time constant of fall in isovolumic left ventricular pressure (T) and systemic vascular resistance (SVR), whereas stroke volume index (SVI) and left ventricular end-diastolic pressure (LVEDP) remained unchanged. Central venous pressure (CVP) was significantly ( P << 0.05) increased at 5%. Myocardial oxygen consumption (MV(O)(2)), and myocardial lactate extraction ratio (ML ext) were decreased in a dose-dependent manner ( P << 0.05). Myocardial oxygen extraction ratio (M(O)(2) ext) was significantly ( P << 0.01) decreased at 5%. The ratio of the left ventricular minute work index to myocardial oxygen consumption (LVMWI/MV(O)(2)), i.e., left ventricular efficiency was significantly decreased only at 5% ( P << 0.05). Coronary sinus blood flow (CSBF) was significantly ( P << 0.05) decreased only at 2.5% sevoflurane and coronary vascular resistance (CVR) was significantly ( P << 0.01) decreased only at 5% sevoflurane. The ratio of CSBF to CO (CSBF/CO) showed a tendency to increase as sevoflurane concentrations were increased. Nicardipine (0.01 mg.kg(-1)) administered intravenously under 2.5% sevoflurane caused significant ( P << 0.05 to P << 0.01) decreases in SAP, HR, LV dP/dt, SVR, and CVR, and increases in CVP, SVI, CI, and CSBF ( P << 0.05 to P << 0.01). CSBF/CO remained unchanged. MV(O)(2), M(O)(2) ext, and ML ext were significantly ( P << 0.05 to P << 0.01) decreased. LVMWI/MV(O)(2) showed a tendency to increase. It is concluded that sevoflurane causes a rapidly and easily controlled cardiovascular depression and may not have unfavorable effects on coronary circulation and myocardial metabolism. Nicardipine exerts a synergistic myocardial depressant effect on sevoflurane, in terms of both cardiovascular dynamics and myocardial metabolism.

Incorporation of partially purified cation channels from cardiac sarcolemmal membrane into planar lipid bilayers

Voltage-dependent calcium channels are vital to cardiac muscle contraction. Therefore it is very important to isolate physiologically active channel proteins, however there have been few reports on their solubilization and reconstitution. Highly purified sarcolemmal membranes from bovine cardiac muscle were solubilized with octylglucoside, partially purified by gel filtration, and reconstituted into planar lipid bilayer by the direct insertion method. At least, two cation channel activities were observed: one with about 4.2 pS and the other with about 28 pS in conductance. From the reversal potential, it was concluded that Ba2+ ions are the current carrier through these two channels.

Analgesic dose-response relation in cervical epidural block

The relationship between the age and the spread of analgesia from different epidural anesthetic doses was examined by studying analgesic dose responses in cervical epidural analgesia. Two different anesthetic doses (5 ml or 10 ml) of 2% mepivacaine were injected into the cervical epidural space at a constant pressure (80 mmHg) using an intravenous apparatus, and the spread of analgesia to pinprick was assessed. The significant correlation was found between the patient's age and the number of spinal segments blocked (5 ml : r = 0.8498, P < 0.01, 10 ml : r = 0.5988, P < 0.01). The inverse linear relationship was found between the patient's age and the segmental dose requirement (5 ml : r = -0.6754, P < 0.01, 10 ml : r = -0.5784, P < 0.01). Patients under 39 years of age showed a direct relationship between the dose injected and the number of spinal segments blocked, enabling prediction of the number of segments blocked with a given dose of local anesthetic. Doubling the epidural dose approximately doubled the number of spinal segments blocked. The analgesic dose-response relation in patients over 60 years of age differed from that in patients under 39 years of age and doubling the epidural dose did not double the number of spinal segments blocked. Progressively more extensive analgesia was obtained from a given dose of local anesthetic with advancing age. It was difficult to limit the extent of analgesia by injecting a smaller dose of local anaesthetic in the elderly.

The effect of verapamil on halothane-epinephrine or digitalis-induced ventricular dysrhythmias in dogs

The effect of verapamil on ventricular dysrhythmias was evaluated using two canine models. In one model, ventricular dysrhythmias were induced by 1% halothane-epinephrine (1.5 approximately 30 micro g/kg/min.) in 20 dogs (Group I). In the other model, ventricular dysrhythmias were induced by digoxin (0.1 approximately 0.2 mg/kg) in 27 dogs (Group II). Verapamil (0.2 approximately 0.5 mg/kg) was given to treat these ventricular dysrhythmias. When verapamil was ineffective, lidocaine (1 approximately 2 mg/kg) was given following the administration of verapamil. In 7 dogs of group II, lidocaine alone was given. Verapamil was effective in 16 animals of group I, and in 10 animals of group II. Lidocaine was ineffective in the remaining 4 of group I, whereas effective in the remaining 17, including those given lidocaine alone of group II. From these findings, it was inferred that Ca(2+) dependent abnormal automaticity and/or re-entry may be more closely related to the genesis of halothane-epinephrine-induced ventricular dysrhythmias refractory to lidocaine, whereas triggered activity may be more closely related to that of digitalis-induced ventricular dysrhythmias. In conclusion, verapamil was more effective against halothane-epinephrine-induced ventricular dysrhythmias than against digitalis-induced ventricular dysrhythmias.

Epidural pressure and its relation to spread of epidural analgesia

The relationships between the epidural pressures following the injection of local anesthetic solution and the spread of epidural analgesia were investigated. In 46 patients, 15 ml of 2% mepivacaine was injected into the lumbar epidural space at a constant rate (1 ml/sec) using an electropowered syringe pump. Injection pressures and residual pressures were recorded and the spread of analgesia to pinprick was assessed. The changes of the epidural pressures during and following the injection of a volume of local anesthetic solution in old subjects were significantly smaller than those in young subjects (P < 0.05). The spread of analgesia closely correlated with the epidural pressures during and following the injection of local anesthetic solution. The most close correlation was found between the epidural pressure immediately after the completion of injection and the spread of analgesia (r = -0.5659, P < 0.001). In conclusion, the lower the terminal injection pressure and the residual pressures associated with higher age, the wider the spread of epidural analgesia.

Spread of epidural analgesia following a constant pressure injection

(1) The spread of epidural analgesia following injection of 15 ml of 2% mepivacaine was 17.3 +/- 0.6, 14.3 +/- 0.4, and 13.3 +/- 0.7 spinal segments in cervical, thoracic, and lumbar epidural analgesia, respectively. The patient's age showed significant correlation with the spread of epidural analgesia in cervical (r = 0.5776, p < 0.001), thoracic (r = 0.3758, p < 0.01), and lumbar area (r = 0.8195, p < 0.001). The spread of cervical epidural analgesia was more caudad than cephalad (p < 0.05), but in lumbar epidural analgesia it was more cephalad than caudad (p < 0.05). There was no difference between the cephalad and caudad spread in thoracic epidural analgesia. (2) The epidural pressure immediately after injection of 15 ml of 2% mepivacaine into the lumbar epidural space at a constant pressure (80 mmHg) correlated to the patient's age (r = -0.5714, p < 0.001) and the spread of analgesia (r = -0.3904, p < 0.05). The lower epidural pressure associated with higher age, the wider spread of analgesia. There was no significant correlation between the residual pressure at 60 seconds and the age or the spread of analgesia.

[A case of ulcerative colitis relapsing at the defunctionalized colon after subtotal colectomy]

A 25-year-old female with left sided ulcerative colitis underwent subtotal colectomy, and colo-anal anastomosis with diverting ileostomy by combined abdomino-sacral approach on February 14, 1985. Immediately after the operation, bleeding from the anus occurred, and one month after the operation, endoscopic examination revealed the relapse of the ulcerative colitis in the remaining colon. It was recognized, that relapse had occurred postoperatively at the nonfunctioning colon, which had been free from the disease so long as eight years since the onset of the disease. Then the relapsed colon was removed, and ileoanal anastomosis with diverting ileostomy was performed, again by combined abdomino-sacral approach. The sacral approach offered an excellent operative field and ensured the anastomosis between the small intestine and the anus.

[An evaluation of the multidisciplinary treatment of carcinoma of the maxillary antrum in head and neck surgery]

Radiation therapy combined with surgery or regional chemotherapy was given to 114 cases of squamous cell carcinoma of the maxillary antrum from 1972 to 1983 at Gunma Cancer Center. The each treatment method was contributed to successful multidisciplinary treatment consists of partial maxillectomy, radiation therapy doses of 40 Gy and regional chemotherapy using 5 FU doses of over 2,000 mg. The 5 year cumulative survival rate was 34.7% in this study. The role of minor surgery of the antrum after radiation and chemotherapy was available for irradiated necrotizing tumor tissue, residual lesion or bone necrosis of the antrum. This additional surgery was very useful as a post radio-chemotherapeutic treatment in this study of multidisciplinary treatment.