Influence of PHA stimulation on the cytotoxicity and mutagenicity of X-rays and ethylnitrosourea in human peripheral blood T-lymphocytes.

We investigated the effects of mitogenic stimulation on the cytotoxicity and mutagenicity of X-rays and ethylnitrosourea (ENU) in human peripheral blood lymphocytes using a cloning technique. Resistance to 6-thioguanine (TG) served as the genetic marker. Day 0 (unstimulated) lymphocytes were about two times more radiosensitive than day 3 (stimulated) lymphocytes to the cytotoxicity when compared for the D0 value (0.72 Gy vs. 1.54 Gy), and about five times more radiosensitive to its mutagenicity when compared for the frequency of TG-resistant cells following exposure to 4 Gy of X-rays (25.5 x 10(-6) vs. 126.0 x 10(-6). On the other hand, day 3 (stimulated) lymphocytes were about three times more sensitive to ENU with a D37 value of 1.03 mM compared with 2.82 mM for day 0 (unstimulated) lymphocytes, but as sensitive as day 0 lymphocytes to its mutagenic effect. These results indicate that the sensitivity of lymphocytes for cytotoxicity and mutagenicity is modified by mitogen stimulation, when lymphocytes are exposed to carcinogens or mutagens in vitro.

Low dose radiation-induced adaptive survival response in mouse spleen T-lymphocytes in vivo.

Induction of an adaptive survival response in B6C3F1 mice exposed to whole-body irradiation by low doses of X-rays (priming exposure) then to high doses of X-rays (challenge exposure) was examined. The adaptive survival response was determined by comparing the cloning efficiency of low dose-irradiated spleen T-lymphocytes to that of unprimed controls. Maximal expression of the adaptive survival response induced by exposure to low doses of X-rays occurred 7 hours after the priming exposure. The optimal low dose range for the induction of the adaptive survival response was 0.05-0.1 Gy. Thus, low dose X-irradiation induces the adaptive response in spleen T-lymphocytes of B6C3F1 mice as assessed by survival. The duration of this response is short, and there is an optimal low dose range. The Dq value for the primed cells was somewhat larger than that for the unprimed ones. Low dose exposure may enhance the capacity of spleen cells for repair during priming.

Individual variation and age dependency in the radiosensitivity of peripheral blood T-lymphocytes from normal donors.

To investigate individual variation and age dependency in normal cell radiosensitivity, we measured the in vitro radiosensitivity of cultured peripheral blood T-lymphocytes derived from 56 healthy male blood donors. Dose-survival tests using colony formation assay were done with exponential growing T-cells (day 3, PHA-stimulated cells). 6-Thioguanine (6-TG)-resistant mutation assays at the hypoxanthine phosphoribosyl transferase (HPRT) locus were done with G0 phase T-cells (day 0, unstimulated cells). The mean inactivation dose (MID) computed by integration of the fitted survival curves was 1.25 +/- 0.23 Gy (mean +/- SD). The X-ray dose required to kill 90% of the cells (D10) was 2.81 +/- 0.51 Gy. The MID ranged from 0.82 to 1.86 Gy with a coefficient of variation (CV) of 18%. The induced mutation frequencies (MF) per 10(6) cells at 2 Gy of X-rays ranged from 9.10 to 54.80 with a mean +/- SD value of 24.63 +/- 12.51 and a CV of 51%. It appears that the radiosensitivity of cell killing and mutagenicity varies among individuals. Although the spontaneous MF at the HPRT locus increases with age, the induced MF after exposure to 2 or 4 Gy of X-rays was not associated with age. Moreover, there were no significant correlations between age and MID values or the other dose-survival parameters. The findings indicate there is significant inter-individual variation in cellular radiosensitivity, but that in human T-lymphocytes aging does not affect the cytotoxic and mutagenic effects of X-irradiation.

Studies on methylthymol blue-I Separation and purification of methylthymol blue and semimethylthymol blue.

The metallochromic indicator Methylthymol Blue was purified chromatographically with cellulose and ion-exchange resin columns. The monosubstituted product of the reaction, Semimethylthymol Blue, was also separated and purified, and can also be used for the colorimetric determination of metals. There are not marked differences between the infrared spectra of Methylthymol Blue and Semimethylthymol Blue. The purities of Methylthymol Blue and Semimethylthymol Blue finally obtained were above 97% and 90% respectively. In acidic medium Methylthymol Blue forms 1:1 greyish blue and 1:2 pure blue chelates with copper(II) whilst Semimethylthymol Blue forms only 1:1 orange chelates with bivalent metals. The molar absorptivities at 435 mmu are 1.89 (+/- 0.03) x 10(4) for Methylthymol Blue at pH 5.00 and 1.76 (+/- 0.03) x 10(4) for Semimethylthymol Blue at pH 5.45.

Acquisition and maintenance of postshock response pattern in nondiscriminated avoidance with rats.

Five experimentally naive albino rats were placed under a nondiscriminated lever-press avoidance schedule in which the delay to the next shock for responses after a shock was longer than the delay for responses after a response. Four rats acquired the postshock response pattern and maintained it for a prolonged period. The results revealed that postshock responding was under operant control and was not purely shock-elicited. It was suggested that the two kinds of response-shock interval, i.e. the shock-response-shock interval and the response-response-shock interval, could and should be independently controlled in nondiscriminated avoidance schedules.

Differential outcome effect in the horse.

Three horses were trained with a discrimination task in which the color (blue or yellow) of a center panel signaled the correct (left or right) response (lever press). Reinforcing outcomes for the two correct color-position combinations (blue-left and yellow-right) were varied across phases. Discrimination performance was better when the combinations were differentially reinforced by two types of food (chopped carrot pieces and a solid food pellet) than when the combinations were randomly reinforced by these outcomes or when there was a common reinforcer for each of the correct combinations. However, the discrimination performance established by the differential outcome procedure was still 80% to 90% correct, and an analysis of two-trial sequences revealed that the stimulus color of the preceding trial interfered with discrimination performance on a given trial. Our demonstration of the differential outcome effect in the horse and its further analysis might contribute to more efficient control of equine behavior in the laboratory as well as in horse sports.

Magnetic resonance imaging of intracranial venous angiomas.

Magnetic resonance imagings (MRI) were made of intracranial venous angioma (six angiographically proved, four presumed). All draining veins were identified as a linear or a small round structure with a flow void. The stellate configuration was observed in seven of the ten patients. In two of the ten, the associated intraparenchymal hematoma was evident. Increased intensity of adjacent parenchyma on T2-weighted images was detected in four of ten patients, and a decreased intensity on the T1-weighted images was noted in three of eight. Thus, MRI is a pertinent diagnostic modality for evaluating intracranial venous angioma. Angiography does not seem to be required for confirmation in patients with typical MR findings.

Spontaneous abdominal aortic dissection: case report and review.

An abdominal aortic dissection was incidentally imaged by contrast infusion computed tomography (CT) in a patient with an abdominal liposarcoma. Previously reported cases of spontaneous abdominal aortic dissection with radiographs are reviewed.

Strategy changes in human contingency judgments as a function of contingency tables.

Judgment strategies of 169 undergraduate students on problems to judge the contingency between two binary events were identified by the method of rule-based analysis to clarify whether or not the strategies the subjects used would be affected by the concrete nature of the contingency table. Problems were constructed along two factors: total cell frequency and width of range of objective contingencies. Although the factor of total cell frequency had no effect on subjects' strategies, the number of subjects who changed strategies corresponding with problem instances increased when the objective contingencies were set closer to zero or when problems became more difficult. These results are discussed in the context of previous studies of this issue in the literature.

Effects of strong magnetic fields on cell growth and radiation response of human T-lymphocytes in culture.

Experiments were undertaken in order to verify whether or not a strong magnetic field would have any biological effects on the cell growth, viability and radiation response of mammalian cells. Magnetic field exposures were conducted using a superconducting magnet with freshly-isolated human peripheral blood T-lymphocytes maintained at their normal growing temperature of 37 degrees C. The static magnetic fields with intensities up to 6.3-tesla (T) exerted little influence on the cell growth and viability of actively-growing T-lymphocytes under normal cell-culture conditions. On the other hand, the T cells exposed to the magnetic fields (4 T-6.3 T) during PHA stimulation were inhibited in their cell growth when compared to controls. The effects of the magnetic fields with intensities up to 2 T on cell growth properties, however, were minimal in this system. Also, the radiosensitivity of T-lymphocytes previously exposed to the strong magnetic fields was more sensitive than that of control cells. These results suggest that exposure to a static magnetic field of 4 T or stronger might lead to physiological and growth abnormalities at the cellular level.

Panel-touch behavior of horses established by an autoshaping procedure.

Panel-touch behavior of 3 geldings was successfully established by a response-termination type of autoshaping procedure. An omission or negative contingency introduced after the training of an animal, however, decreased the response rate to a near-zero level.

[Situations and cognitive appraisals in 'agari' experiences: feature analyses of 'agari' experiences].

The purpose of this study was to examine the 'agari' experiences in everyday life. 'Agari' is a Japanese noun (the verb form is 'agaru'), referring to broad experiences including stage-fright, choking under pressure, social anxiety, and so on. Based upon the self-reports of 452 subjects, we constructed, in Study 1, a 52-items Features of 'Agari' Experience Questionnaire (FAEQ). In Study 2, another sample of 364 completed the FAEQ, and factor analysis was performed. The analysis found six primary factors: Self insufficiency, physical insufficiency, trembling, pressure, physiological response, and awareness of others. A second-order factor analysis was performed on them, and two factors emerged: Self-reflection and awareness of self-importance. It may be therefore concluded that looking at the self leads to an 'agari' experience. In addition, hierarchical cluster analysis divided twelve 'agari' situations into four clusters. The clusters were differentiated by two factors of FAEQ. It is suggested that eliciting situations and associated cognitive appraisals differentiated 'agari' experiences.

[A comparison of win-shift and win-stay performance of rats in a radial arm maze].

The purpose of the present experiment was to compare the performance of rats in a win-shift task and a win-stay task in a radial arm maze. To this end, three experiments were conducted using a variety of procedures. In general, the win-shift task required the rats to choose the unvisited arms and the win-stay task required the rats to return the visited arms. In Experiment 1, a free-choice memory recognition procedure was used, and in Experiments 2 and 3, a forced-choice memory recognition procedure was used. All three experiments showed that in the win-shift task, rats rapidly learned the task and performed well whereas in the win-stay task, the rats consistently showed a chance-level performance despite of the prolonged training. In addition to these findings, when the tasks were reversed (i.e. from the win-shift to the win-stay, and vice versa), the rats still showed a response strategy previously adopted (Experiment 3). These findings seem to be important in considering the characteristics of spatial memory in rats.

[Computed tomography of thymic hyperplasia in older children].

Computed tomography (CT) findings of 8 cases of thymic hyperplasia in children aged 7 to 15 years were retrospectively analyzed in comparison to 8 cases of tumors of anterior mediastinum. All cases of thymic hyperplasia retained a somewhat triangular or arrowhead-like shape at least on one side while tumors showed bilateral globular contour with lobulated border. No compression of the air way or pleural fluid was observed in thymic hyperplasia. These CT features are useful for making a diagnosis of thymic hyperplasia when an older child is presented with an anterior mediastinal mass on chest X-ray.

Radiotherapy with 8 MHz radiofrequency-capacitive regional hyperthermia for pain relief of unresectable and recurrent colorectal cancer.

PURPOSE: The purpose of this study was to assess the pain relief in patients with unresectable and recurrent colorectal cancer treated with radiation plus 8 MHz radiofrequency-capacitive regional hyperthermia and to identify predictors of the good outcome. METHODS: Between February 1986-May 2003, 41 patients with primarily unresectable and recurrent colorectal cancer that caused pain were treated with thermoradiotherapy at the hospital and retrospectively analysed. Radiotherapy was administered with a mean total radiation dose of 56 Gy. Hyperthermia was usually applied within 30 min after radiotherapy once or twice a week. For cooling of the skin surface, the overlay boluses were applied in addition to regular boluses. The external cooling unit has been used to reinforce the cooling ability of the overlay bolus and achieve strong surface cooling to reduce the preferential heating of the subcutaneous fat tissue and treat with more RF-output in 17 patients since January 1997. RESULTS: Pain relief was obtained in 83% of the patients. Multi-variate analysis by logistic regression to evaluate the effects of certain factors on pain relief (complete response + good response) was strongly correlated with the presence of radiating pain to leg(s) (p < 0.05). The median follow-up was 18 months. The median duration of pain relief was 7.0 months. For the 27 patients in whom the tumour temperature was estimated, the median duration of pain relief was 14.6 months for the patients with a mean average tumour temperature of > 42.5 degrees C and 5.7 months for those of < 42.5 degrees C (p < 0.05). In the 18 patients with radiating pain to leg(s), use of strong superficial cooling and the higher numbers of hyperthermia treatments were better prognostic factors for the duration of pain relief (p < 0.01 and p < 0.05, respectively). CONCLUSIONS: Radiotherapy with 8 MHz radiofrequency-capacitive regional hyperthermia provided an efficient, effective means on pain relief of treating unresectable and recurrent colorectal cancer. The duration of pain relief can be prolonged, if an adequate heating is achieved, especially in the patients with radiating pain to the leg(s).

Protective effect against 17beta-estradiol on neuronal apoptosis in hippocampus tissue following transient ischemia/recirculation in mongolian gerbils via down-regulation of tissue transglutaminase activity.

We analyzed the protective effect of 17beta-estradiol (17beta-ED) injection against delayed neuronal death in the hippocampus tissue of the brain in Mongolian gerbils after transient ischemia/recirculation treatment, especially in relation with bcl-2 gene expression and enzymatic activity changes of caspase-3 and tissue transglutaminase (tTGase). Daily intraperitoneal injection of 17beta-ED to the animal after the ischemia stimulated the expression of an apoptosis suppressor gene, bcl-2, in the hippocampal tissue for a week. The gradually increasing apoptotic enzyme activity of caspase-3 and increased number of TUNEL positive fragmented neuronal nuclei caused by ischemic attack in the gerbil brain were clearly suppressed by 17beta-ED administration. The reduced activity and enzyme protein of tTGase, a neurodegenerative marker of apoptosis in the hippocampus after ischemia, were also restored to nearly normal levels by 17beta-ED injection. These results suggest that daily 17beta-ED administration to the gerbil after transient ischemic insult with progressing neuronal deteriorative changes in hippocampus tissue can effectively prevent apoptotic changes through a molecular cascade involving gene expression regulation.

MR imaging of wallerian degeneration in the human brain stem after ictus.

Magnetic resonance (MR) imaging of wallerian degeneration in the brain stem was studied in 30 hemiplegic patients within 12 months of ictus. As early as 25 days after the ictus, decreased signal intensities on proton-density(PD)-weighted images were observed in the brain stem ipsilaterally. This hypointensity gradually approached an isointense stage during 70-80 days after the ictus, abnormal intensities were not detected in any pulse sequence. We termed this phenomenon "Fogging effect of wallerian degeneration". In later stages, at least 81 days after the ictus, increased signal intensities on T2-weighted images, with or without decreased signal intensities on T1-weighted images, were observed in the brain stem, ipsilaterally. Finally, at least six months after the ictus, mild shrinkage of the ipsilateral brain stem was newly detected on the T1-weighted images. MR imaging has proven to be a sensitive diagnostic modality for evaluating wallerian degeneration in the brain stem.

[Radiological diagnosis of splenic metastasis and its prevalence at autopsy].

CT and US findings of 7 cases of splenic metastases are described and the prevalence of splenic metastases at autopsy in 641 cases with malignant tumors were evaluated. Metastatic foci in spleen appeared mostly as poorly-defined low density masses on CT. Iodinated contrast material was administered in 2 cases, but no contrast enhancement was observed. US showed both hypoechoic and hyperechoic patterns. These appearances were nonspecific, but were similar to those of metastatic lesions in the liver which were often visible on CT associated with splenic metastases. At autopsy splenic metastases were found in 34 of 641 cases (5.3%). Gastric, colon, lung and ovarian cancers were most common primary tumors. However, the rate of splenic metastasis per tumor was highest in ovarian cancer (50.0%), followed by malignant melanoma (33.3%), colon cancer (16.2%) and gastric cancer (8.2%). Hepatoma which had the biggest number of autopsy cases in this series showed the lowest rate of splenic metastasis (0.8%).

Pancoast tumour treated with combined radiotherapy and hyperthermia--a preliminary study.

Six patients with Pancoast (superior sulcus) tumours were treated with combined radiotherapy and hyperthermia from April 1986 to December 1989. Radiotherapy was performed using 10 MV X-ray, and all patients received total doses of 60-74 Gy, in five fractions per week, during 5.5-15 weeks. Hyperthermia was performed once or twice a week within 30 min after each irradiation, using 8 MHz RF capacitive heating equipment (Thermotron RF-8). Partial response, defined as 50% or more regression of the tumour, was observed in four of the six patients. Three patients are alive 30, 28, and 14 months after their treatments. Radiotherapy combined with hyperthermia appears to be a promising and effective means for treating Pancoast tumours.