Major ion and electrical potential distribution in soil under electrokinetic remediation.

To assess the effect of pore water chemistry on the contaminant removal rate, we monitored major ion concentrations in the pore water and the electrical potential distribution of a soil during electrokinetic remediation treatment. On application of the voltage, the soil near the anode became acidic due to the electrolytic generation of H+, and the acid region gradually spread toward the cathode. The major cation in the acid region was, however, not H+ but Al3+ that arose from the acid-induced dissolution of soil minerals, and it migrated very slowly toward the cathode. The measured pH and accompanying ion concentrations indicated that the anomalously slow migration of Al3+ was due to its precipitation-dissolution reaction at the acid front. The stagnancy of Al3+ increased the ionic concentration, flattened the electrical potential profile, and in turn, diminished electromigration in the acid region. This seems to be one of the causes of the relatively low removal rate of cationic and anionic contaminants in electrokinetic treatments.

[Auditory steady-state response to sinusoidally amplitude-modulated tones. Second report: investigation of response in the sleeping state].

The auditory steady state response (SSR) elicited by a sinusoidally amplitude-modulated (SAM) tone may be an important technique in objective audiometry, which provides frequency-specific information. This response is affected the state of arousal of the subject. An effect of sleep on the amplitude of this response has been observed by a number of previous investigators. Since young children must usually be sedated to carry out evoked potential testing, the effects of sleep on this response are a crucial factor limiting clinical applicability. The basic characteristics of SSR elicited by a 500 Hz SAM tone were studied in 21 adults with normal hearing during sleep. The responses while sleeping were compared with the responses in the awake state. The responses to 2048 stimuli were averaged with the analysis time set at 102.4 ms, and responses were judged by passing the waveforms through a 20-100 Hz digital filter. The same technique was performed in 25 infants (2 months-2 years 9 months) evaluated as having normal hearing. The results obtained are summarized as follows: The amplitude of the response while sleeping was approximately half the amplitude in the awake state. Responses with a modulation frequency of 70Hz, however, showed a persistent decrease in 71.0%, suggesting a trend different from that seen at a modulation frequency of less than 70Hz. The effect of modulation frequency on response amplitude was almost the same for the sleeping state and the awake state. Even during sleep, the response amplitude was maximal at modulation frequencies of 20, 30 and 40Hz, and there was no significant difference between the values at 20Hz -40Hz. The latency of the response was measured by the Diamond method, and the results showed that latency is significantly prolonged while sleeping (p < 0.01). The response threshold at the 500Hz SAM tone (modulation rate 40Hz, modulation depth 90%) was 8.5dBnHL when awake and 13.9dBnHL during sleep. The rise in threshold as a result of sleep was no more than about 5dB. In infants, the response amplitude at a modulation frequency of 20Hz was maximal, and amplitude at the 40Hz was significantly smaller (p < 0.01). Latency measured by the Diamond method in infants was 12.8ms. Thus, a difference from the response in adults was confirmed. Comparisons were made between the responses of infants under 1 year of age and infants over 1 year of age to confirm changes in response according to age.

Effect of natural sleep on auditory steady state responses in adult subjects with normal hearing.

Auditory 40-Hz steady state response (SSR), auditory brainstem response (ABR), and middle-latency response (MLR) were recorded in 12 healthy adult females with normal hearing while awake and asleep. The responses were recorded with 500-Hz tone pips at 55 dBnHL. Synthesized SSR were made by superimposing the recorded ABR and MLR waveforms (ABR-MLR), and their amplitudes were compared with those of the actually recorded SSR. In the waking state, the ratio of the mean amplitude of recorded SSR to that of synthesized SSR was 0.819, whereas in the sleeping state it decreased to 0.522, a statistically significant difference. The results indicate that the SSR can be predicted from the linear superimposition of ABR and MLR in the waking state, but not in the sleeping state.

[Auditory steady-state response to sinusoidally amplitude-modulated tones. First report: investigation of response in the awake state].

Basic characteristics of the steady state response (SSR) evoked by sinusoidally amplitude-modulated tone (SAM tone) were studied in 26 awake adults with normal hearing. This study was designed to determine how this response to SAM tone effects the objective hearing test. The responses to 2048 stimuli were averaged with an analysis time set at 102.4 ms and were digitally filtered with a pass band of 30-100 Hz. The results obtained are as follows. With a carrier frequency of 500 Hz, the response amplitude was maximal at a modulation frequency of 30 or 40 Hz and decreased rapidly at 50 Hz. The response amplitude increased linearly with an increase in the modulation depth shown on a logarithmic scale. The mean latency of this response, as determined by the Diamond method, was 37.5 ms. The response amplitude increased with an increase in the stimulus intensity, but the rate of increase was highest at a carrier frequency of 500 Hz and tended to become smaller with increasing carrier frequency. At carrier frequencies of 500 and 1000 Hz, response detectability reached 100% with a stimulus intensity of 30 dBnHL, while at the higher frequencies, 100% detectability was attained at 40-50 dBnHL. The mean response thresholds were 15.0 dBnHL, 13.1 dBnHL, 25.3 dBnHL and 30.0 dBnHL at 500, 1000, 2000 and 4000 Hz, respectively.

Effect of sleep on binaural interaction in auditory brainstem response and middle latency response.

Binaural interaction (BI) in auditory brainstem response (ABR) and middle latency response (MLR) was measured in 14 adults with normal hearing in the awake and asleep states. The ABR and MLR were recorded with click stimuli given monaurally and binaurally. Four peak-to-peak amplitudes of the response waveforms were measured, and the BI was determined from the amplitude difference between the summed monaural and binaural responses expressed in percent of the summed monaural responses. The magnitude of BI was smallest in ABR (waves I'-V) and largest in the later component of MLR (Pa-Nb) in both the waking and sleeping states. BI values for the peak-to-peak amplitudes in the ABR and MLR were significantly lower (p less than 0.025) in the sleeping state than in the waking state.

Effect of sleep on binaural interaction in human auditory evoked potentials.

Binaural interaction (BI) in ABR, MLR and two kinds of 40-Hz steady-state responses (SSRs) were measured in the waking and sleeping states in normal adults. Eleven samples each were collected from 20 subjects. The ABR and MLR were elicited with 500-Hz tone pips. The SSRs were elicited with the same tone pips (pipSSR) or sinusoidally amplitude-modulated tones of the same frequency (samSSR). The amplitude differences between the summed monaural and binaural responses relative to the summed monaural responses were referred to as BI. ANOVA showed that the mean BI in the responses tested was significantly lower (p < 0.005) in the sleeping state than in the waking state. Ad hoc analysis revealed that the significant difference (p < 0.05) in BI between the waking and sleeping states occurred in the pipSSR and samSSR. The BI became larger in the order, ABR, samSSR, pipSSR, MLR, in both the waking and sleeping states. Significant differences (p < 0.05) were detected in the BI during sleep between the MLR and each of the other three responses, whereas in the waking state no significant difference was found between the MLR and tone-pip SSR.

Classification of the 16,471 patients treated by radiation therapy from 1962 to 1986, and crude five-year survival rates of patients in each category of radiotherapy treatment from 1962 to 1978 in the National Cancer Center Hospital.

The summation and classification of patients registered for planned radiation therapy in the 24-year period from 1962 to 1986, in the Department of Radiation Therapy, National Cancer Center Hospital, are reported. Patients numbered 16,471, and total sessions of treatment were 26,175. The ratio of the two figures, 1.58, is the average number of treatment sessions per patient. Peak age was 61-65 years' old and 56-60 years old, respectively for males and females. The most frequent primary site of disease for radiation therapy was the head and neck, followed by trachea, bronchus and lung, crevix uteri, breast, and esophagus. Frequency of squamous cell carcinoma was 38.0%; that of adenocarcinoma was 20.9%. Radical treatment was performed in 32.0% of patients in the first session, but this figure decreased to 24.7% for all sessions. There were many cases of secondary and primary palliative treatment, i.e., 31.8%. Radiotherapy was done in 70% of patients by megavoltage X-ray, with 9.4% treated by electron beam. Crude 5-year survival rates for each classification of malignant disease respective to the category of treatment policy from 1962 to 1978 were obtained. Among the radical treatment group, head and neck tumors, skin cancer, and Hodgkin's disease showed 5-year survival rates greater than 50%.

[Clinical usefulness of lymphoscintigraphy by rectal submucosal injection of radioactive colloid].

Lymphoscintigraphies about 27 cases were examined by the methods of 11 cases of anal subcutaneous and 17 cases of rectal submucosal injections of 99mTc-rhenium colloid. Para-aortic nodes and common iliac nodes were visualized in more than 70% out of the 27 cases by these methods, and those images were superior to images obtained by the conventional methods with pedal subcutaneous injections. Internal iliac nodes were visualized in 78.1% by the rectal injection method while in 27.3% by the anal injection method. It was concluded that the transrectal injection method should be used to visualize internal iliac nodes. Examination efficacies of lymphoscintigraphies by these methods on detection of lymph nodes metastases which were confirmed by autopsy, operation, contrast lymphoangiography and/or X-ray CT. As for 131 regions of rectal and anal injected cases, sensitivity was calculated at 84.0% and specificity was at 89.6%. When the cases in which more than one definite defect was detected were scintigraphycally diagnosed as positive to metastasis and when calculated case by case, sensitivity was calculated at 90.9% and specificity was at 62.5% in the 27 cases. Lymphatic systems were seen specifically and systematically by using lymphoscintigraphies. Though the sensitivity was not enough for a screening test of lymph node metastases and the specificity was not enough for a test to rule out lymph node metastases, lymphoscintigraphies are clinically very useful as supplementary examinations. The lymphoscintigraphy by the method of rectal submucosal injection is much more useful as it is convenient and is the only one method to visualize the internal iliac nodes systematically.

[Clinical experience in patients with Pancoast's tumor treated by fast neutron therapy].

We review our results with fast neutron therapy in Pancoast's tumor, and compare them with results obtained by photon beam therapy. 13 patients with Pancoast's tumor were divided into two groups; Group I (8 patients) received fast neutron therapy. Group II (5 patients) were treated by voltage X-ray therapy. 1. Group I was comprised of 3 patients receiving mixed beam therapy (TDF 80-100) and 5 patients subjected to boost therapy. All group II patients received 3100 to 8000 rads. 2. Fast neutron therapy was effective in 7 patients. In group II, high voltage X-ray therapy was effective in only 3 patients. 3. Two group I patients are still alive without signs of recurrence. The others died with a mean survival of 11 months. All group II patients died; their mean survival was 4.2 months. Our results suggest that fast neutron therapy is suitable and effective in patients with Pancoast's tumor.

Clinical evaluation of intraoperative radiotherapy for carcinoma of the urinary bladder.

Intraoperative radiotherapy using one shot high dose electron irradiation was performed for 116 bladder cancer patients as a radical means of treatment for superficial bladder cancer. Additional fractionated external supervoltage irradiation covering the whole bladder was given in most of the cases. The one-, three-, and five-year survival rates were 100%, 100%, and 96.3% for T1 cases and 100%, 87.2%, and 61.6% for T2 cases, respectively. Heterotropic recurrences in the bladder were 5.3% within one year, 9.4% within two years, and 19.3% within five years, respectively. Normal vesical function was well preserved except in five patients who underwent total cystectomy subsequently because of multiple recurrences after radiotherapy and one patient who underwent urinary diversion because of contracted bladder and progressive bilateral hydronephrosis. Intraoperative radiotherapy was established as a reliable and superior method for the treatment of superficial bladder cancer because of the low recurrence rate and good preservation of vesical functions after treatment.

Intraoperative radiotherapy for advanced carcinoma of the biliary system.

Since November 1973, intraoperative radiotherapy has been performed on five patients with unresectable, advanced carcinoma of the bile duct at the hepatic hilus and six patients with unresectable carcinoma of the gallbladder. A treatment cone with a diameter ranging from 4--10 cm was directly applied at the lesion. A single dose of 2500--3000 rad with 11 to 20 meV electrons was delivered. In all patients, recanalization of the obstructed bile duct was observed by the postoperative cholangiography. The local efficacy was confirmed histopathologically in eight autopsied materials and a specimen resected 105 days after radiotherapy. Mean survival time of patients with unresectable tumors was 10.9 +/- 5.6 (SD) months after this radiotherapy. Intraoperative radiotherapy increased the effectiveness and length of palliation for the unresectable lesion.