Neurons in the temporal cortex changed their preferred direction of motion dependent on shape

To investigate neuronal mechanisms that integrate different visual modalities such as motion and shape, neuronal activities in the superior temporal polysensory area (STP) were recorded from monkeys that were watching rotating images. In total, 194 neurons were identified as visually responsive. Of these, 73 neurons (38%) showed differential response depending on both shape and direction of motion (MS neurons). Of these 73 neurons, 21 (29%) were identified as reversal type MS neurons (MSr neurons), that is, they responded to an opposite preferred direction when the shape was different. The results confirm that neurons in the STP can be simultaneously activated by different attributes of visual stimuli. The data also suggest that individual STP neurons can process more than one type of visual stimulus.     

Anterior screw fixation combined with posterior interlaminar fusion for fracture of axis: report of two cases

Two cases of axis fracture are reported. Traffic accidents were the cause of injury in both cases. The odontoid process was dislocated anterolaterally with fracture of the lateral mass of the axis in both cases. In Case 1 good alignment of the atlas and axis could not be maintained even with a Halo-vest. The case 2 patient with spinal cord compression caused by dislocation of the axis was referred to our hospital 8 weeks after the accident. Both cases were surgically treated in a similar fashion. Because of the lateral mass fracture and lateral displacement of the atlas relative to the axis, posterior screw fixation with interlaminar fixation (Magerl) was thought to carry a risk of causing damage to the vertebral artery. Because of this, anterior screw fixation combined with posterior wiring was conducted. First, the odontoid process was fixed anteriorly by a screw because it was able to be placed back in good alignment while the patient was in the supine position. Then, the posterior C1-2 interlaminar wiring with iliac bone graft was added. Rigid fixation was obtained without any complication. Various kinds of fixation, such as posterior interlaminar wiring, odontoid screw fixation and Magerl's fixation, have been reported for the treatment of unstable axis fracture. Among them Magerl's method has been regarded as the most stable. When it is not applicable, combination of the first two methods can be an alternative way of treatment for this odontoid process fracture.     

Effects on health status in students from attending a "juku"]

Between November and December 1993 a questionnaire survey concerning the lifestyle and health status was performed on 1.314 elementary school children living in Tokyo and its suburbs. In this study the following items were included: 1) sleeping habits, 2) physical activity, 3) playing habits, 4) eating habits, 5) attending a "juku", private cram school to prepare children for entrance examinations, 6) commuting hours, 7) 20 subjective symptoms regarding health, and so on. The results were as follows: 1. 61.9% of students were attending a "juku". 2. The number of hours of sleep, playing after school and watching TV decreased with the frequency of attending a "juku". The students who were attending "juku" more than 3 times a week had the shortest number of those hours, and the students who did not attend any "juku" had the longest of those hours. 3. To determine health status, 20 subjective symptoms were scored. The average number of subjective symptoms was 5.0. That of the students who were attending "juku" more than 3 times a week was 5.5. 4. Of the 20 subjective symptoms, 7 items were correlated to the frequency of attending "juku". To remove the effect of other factors, multiple logistic regression analysis was applied to determine correlation of 7 subjective items and other factors including attending "juku". As a result attending "juku" more than three times a week were associated with the two symptoms of "sleepy" and "eye fatigue".     

Novel experimental model using free radical-induced emesis for surveying anti-emetic compounds from natural sources.

A novel experimental model of free radical-induced emesis for screening anti-emetic compounds from natural sources was established. 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) dissolved in liposome induced emesis in young chickens, and the emesis was prevented by antioxidants including N-(2-mercaptopropionyl)-glycine (MPG), alpha-tocopherol, and L-ascorbic acid. Tropiseton, a serotonin receptor antagonist, also prevented emesis induced by AAPH. Known anti-emetic drugs and anti-emetic principles from natural sources also showed significant retching inhibition in the experiment using this system.     

Distribution of diaphragm blood flow during sevoflurane anaesthesia in dogs

Purpose

The purpose of this study was to determine the effect of increasing the concentrations of sévoflurane anaesthesia on the distribution of diaphragm blood flow (Qdi) in ten dogs during mechanical ventilation.

Methods

Animals were divided into two groups, sévoflurane (n = 6) and time control (n = 4) groups. Blood flow to the crural and the costal diaphragm (Qcru, Qcost) was determined by the hydrogen clearance technique at 0, 0.5, 1.0 and 1.5 minimum alveolar concentration (MAC) of sévoflurane after a 30 min period of steady-state conditions. Cardiac output (CO) and the mean arterial blood pressure (MBP) were also measured.

Results

Sevoflurane anaesthesia caused a reduction in CO (L · min^?1) from a control value of 1.51 ± 0.21 to 1.38 ±0.1 (0.5 MAC), 1.09 ± 0.15 (1.0 MAC) and 0.98 ± 0.12 (1.5 MAC) (Mean ± SD). Mean blood pressure, Qcru and Qcost also decreased with increasing depth of anaesthesia. In addition, the decrease of Qcru was greater than that of Qcost at all levels of MBP and CO. No change occurred in these variables in the lime control group.

Conclusion

Sevoflurane anaesthesia changes the distribution of Qdi with a greater reduction occurring in Qcru than in Qcost.     

A fundamental study of Copper-T (intrauterine device). Part 1 (author's transl)]

Copper IUDs and polyethylene IUDs were inserted in Clauberg rabbits. Proliferation of endometrium caused by exogenous progesterone was markedly inhibited in the rabbits with the copper IUD. Maximum proliferation was seen in the contralateral uterine horn of the rabbits with polyethylene IUDs. The concentration of Cu-ion in the endometrium in the horn with Cu-IUD showed a higher level as 19.5 ug/g wet wt. than that in the control horn, 2.5 ug/g wet wt. This effect corresponds to the addition of Cu-ion in a concentration of higher dosage to the endometrium of the control horn. In the case of women with normal menstrual cycles, the increase in a concentration of Cu-ion in the endometrium with Cu-IUD was lower than 10-5M; in the control women the concentration was 1.6 ug/g wet wt. of endometrium. The histological dating of endometrial specimens (E-B date) with Cu-IUD was examined and compared with expected date of the cycle determined by BBT date. Cu-IUD did not induce any significant discrepancy in both dating. The mechanism of increasing contraceptive effect with Cu-ion was considered to be a little different than in rabbits. (Author's Modified)     

Effects of DPI 201-106, a novel cardiotonic agent,on hemodynamics,cardiac electrophysiology and arrhythmias induced by programmed ventricular stimulation in dogs with subacute myocardial infarction: A comparative study with dobutamine

Summary DPI 201-106 (DPI), a novel and potent cardiotonic agent, exhibits its effects by prolonging the open state of Na⁺ channels, resulting in an increase in action potential duration, and thus, is supposed to share the class III antiarrhythmic activity. The effects of DPI on the hemodynamics, intraventricular conduction and refractoriness of heart, and the incidence of arrhythmias induced by programmed electrical ventricular stimulation (PES) were compared with (±)-dobutamine. Dogs which survived for 5 to 7 days after the induction of myocardial infarction were used as the model. The presence of sub-acute myocardial infarction caused by occluding the left anterior descending coronary artery elicited a mild left ventricular dysfunction represented by a significant decrease in peak LV dp/dt by about 20%.Both i.v. bolus injection of DPI (1, 3 and 5 mg/kg) and i. v. continuous infusion of dobutamine (3, 5 and 10 g/kg/min), which were administered in a cumulative manner, dose-dependently improved the hemodynamic parameters. At the higher doses of both DPI (3 and 5 mg/kg) and dobutamine (5 and 10 g/kg/min) the control values were reached or even exceeded. DPI dose-dependently increased the effective refractory period (ERP) of both non-infarcted and infarcted ventricular myocardia to a similar degree, but the conduction time showed a frequency-dependent increase in the infarcted myocardium to a greater degree than in the non-infarcted myocardium after DPI. In contrast, dobutamine decreased the ERP in both non-infarcted and infarcted myocardia, and slightly increased the difference of refractoriness between the non-infarcted and infarcted zones with no effect on the intraventricular conduction. In the PES study, DPI (3 and 5 mg/kg) produced a significant decrease in the incidence of ventricular tachycardia, whereas dobutamine (5 and 10 g/kg/min) tended to worsen the arrhythmias. These findings suggest that cardiotonic agents with a class III antiarrhythmic property such as DPI may be potentially useful for the management of heart failure accompanied by ischemic heart disease.Abbreviations DPI, DPI 201-106; PES programmed electrical ventricular stimulation - LV dp/dt the rate of rise of left ventricular pressure - ERP effective refractory period - RVOT right ventricular outflow tract - VT ventricular tachycardia - LAD left anterior discending coronary artery Send offprint requests to T. Uematsu at the above address     

Penetration of etoposide into human malignant brain tumors after intravenous and oral administration

Summary Penetration of etoposide into the cerebrospinal fluid, brain tumor, and brain tissue after intravenous administration was investigated in patients presenting with malignant brain tumors. A relatively low dose (55–65 mg/m²) was used to compare intravenous with oral administration. High-performance liquid chromatography with fluorescence detection was used to evaluate drug levels. Plasma and cerebrospinal fluid levels of etoposide after oral administration (50–150 mg/day) were also studied so as to determine the adequate oral dose for the treatment of malignant brain tumors. The peak plasma concentration after intravenous administration ranged from 7.01 to 10.47 g/ml, varying in proportion to the injected dose, whereas that after oral administration was lower, namely, 1.44–4.99 g/ml, and was unstable when the oral dose was 150 mg daily. The peak cerebrospinal fluid level following either intravenous or oral administration was much lower than the plasma concentration and was influenced by the peak plasma level and the sampling site. The etoposide concentration in cerebrospinal fluid taken from the subarachnoid space and ventricle of patients displaying no tumor invasion and of those presenting with meningeal carcinomatosis and in cerebrospinal fluid taken from the dead space after tumor resection was 0.7%±0.5%, 3.4%±1.0%, and 7.2% ± 8.5%, respectively, of the plasma concentration. Serial oral administration did not result in the accumulation of etoposide in cerebrospinal fluid. The tumor concentration (1.04–4.80 g/g) was 14.0%±2.9% of the plasma level after intravenous administration, was related to the injected dose, and was approximately twice the concentration detected in the brain tissue. Therefore, a relatively low dose of etoposide injected intravenously penetrates the brain tumor at an efficacious concentration. Our results indicate than an oral dose of 100 mg etoposide be given for malignant brain tumors, as limited penetration of the drug into the intracranial region was observed.     

Acute toxicity,percutaneous absorption and effects on hepatic mixed function oxidase activities of 2,4,4′-trichloro-2′-hydroxydiphenyl ether (Irgasan® DP300) and its chlorinated derivatives

Acute toxicity of 2,4,4-trichloro-2-hydroxydiphenyl ether (Irgasan^® DP300) (I) and its three chlorinated derivatives, 2,3,4,4-tetrachloro-2-hydroxydiphenyl ether (II), 2,4,4,5-tetrachloro-2-hydroxydiphenyl ether (III) and 2,3,4,4,5-pentachloro-2-hydroxydiphenyl ether (IV), in mice were examined by intraperitoneal injection. The LD₅₀ values of Irgasan DP300, II, III and IV were 1,090, 710, 650 and 430 mg/kg, respectively.The percutaneous absorptions of these tritiated compounds were also examined by the application on the backs of mice. The radioactivities in most tissues reached to the maximal levels at 12 h or 18 h after dosing, which corresponded to 11–76% of the maximal levels given by the oral administration (Kanetoshi et al. 1988a). These results show the high percutaneous absorbability of Irgasan DP300 and its chlorinated derivatives.The intraperitoneal administrations of III and IV to rats induced hepatic microsomal aminopyrine N-demethylase and aniline 4-hydroxylase activities similarly to phenobarbital. These chlorinated derivatives also increased cytochrome P-450 content, and the activities of aminopyrine N-demethylase and N-methylaniline N-demethylase in hepatic microsomes from mice. The extents of the increases were similar to those by phenobarbital and 3-methylcholanthrene.     

Anesthetic management of a patient with Hallermann-Streiff syndrome

Key words  airway management - difficult intubation - Hallermann-Streiff syndrome