Effect of site of stimulation on the guinea pig's electrically evoked brain stem response

Stimulation by a bipolar modiolus electrode yields a wider dynamic range than does monopolar stimulation at the same site. Stimulation via a single electrode in the scala tympani or scala vestibuli is characterized by a precipitous input-output function, but current passing from one scala to the other generates a discontinuous function with a shallow slope at low intensities and a steep slope at high intensities.

Brain stem response evoked by electrical stimulation of the round window of the guinea pig

The wave that is believed to correspond to wave V in man is an appropriate indicator of auditory nerve excitability because it is not contaminated by nonauditory neurogenic responses to electrical stimulation. The responses to direct electrical stimulation of the auditory nerve could be distinguished from the electrophonic response by the steep input-output function and constant latency of the former. Myogenic responses are prominent unless a muscle relaxant is administered.

Alcoholic epilepsy. A definition and a description of other convulsions related to alcoholism

The role of alcohol intake and withdrawal in so-called alcoholic epilepsy is discussed and illustrated by case reports. A classification is made which includes definitions of withdrawal convulsions, tetany-like withdrawal convulsions and alcohol-induced epileptic fits, with or without predisposing features.

Characteristics of three groups of men alcoholics differentiated by age at first admission for alcoholism treatment in Japan

Alcoholics who were first admitted for alcoholism treatment at a psychiatric hospital between 23 and 32 years of age were more likely than alcoholics admitted at a later age to be the firstborn or only child in their family, to have experienced paternal death before age 10 and to have had alcoholic relatives.

Identification of gibberellin A9 methyl ester as a natural substance regulating formation of reproductive organs in Lygodium japonicum

Prothallia of Lygodium japonicum (Thunb.) Sw. were aseptically cultured under white light in a mineral solution. Solvent fractionation of the resultant culture medium and subsequent preparative thinlayer chromatography yielded a fraction that induced antheridium formation and inhibited archegonium formation. Combined gas chromatography-selected ion monitoring analysis of this fraction confirmed the presence of gibberellin A9 methyl ester (GA9-me) as an antheridiogen and an inhibitor of archegonium formation. Exogenously applied [(3)H]GA9 was rapidly converted to [(3)H]GA9-me in the prothallial tissue. Authentic GA9-me was active to 10(-10)M in antheridium formation and to 10(-9)M in the inhibition of archegonium formation.

[Toxicological studies on pepleomycin sulfate (NK631). VI. Chronic toxicity of pepleomycin in dogs (author's transl)]

Chronic toxicity and its recovery of pepleomycin sulfate was studied in both sexes of beagle dogs. At dose levels of 0.3, 0.15 and 0.075 mg/kg, pepleomycin was administered intramuscularly to dogs for 180 successive days. Two dogs of the 0.15 mg/kg dose group were used for recovery test for 35 days. As general findings, the decrease of food intake, the loss of body weight, ulceration of foot pad, nail root necrosis and onychoptosis, ulcer of tongue and labia, and alopecia, dermatitis and necrosis at friction sites were observed more severely in the 0.3 mg/kg dose group of both sexes, especially in male, than those in bleomycin were. In the dose groups of 0.15 and 0.075 mg/kg, their findings were observed as slightly as those in bleomycin were. The death occurred in the 0.3 mg/kg dose group of both sexes. The lesions of liver and kidney were recognized in the 0.3 mg/kg dose group of both sexes, severely in male, on histopathological findings. Additionally severe fibrosis of lung was observed in one of the 0.3 mg/kg dose group of female. In general chronic toxicity of pepleomycin was revealed more severely in the 0.3 mg/kg dose group than that of bleomycin was, but in the dose groups of 0.15 and 0.075 mg/kg difference between their toxicities was not significant. In addition, chronic toxicity of pepleomycin in dogs showed more severely in male and its recovery was hardly recognized during its period. The maximum safety dose in this studies was estimated to be between 0.075 and 0.15 mg/kg in dogs.

Effects of number and interstimulus interval of tone pips on fast responses

Effects of stimulus number and interstimulus interval on auditory-evoked fast responses (BSR: Jewett's V, and middle-latency components: Na, Pa and Nb) were studied by using 1000- and 500-Hz tone pips in 6 normal human adults. At a stimulus intensity of 50 dB SL, 500 stimuli evoked BSRs and the middle-latency components in all cases. At a stimulus intensity of 30 dB SL, 1000 stimuli were necessary to evoke BSRs and Na in all 6 subjects. Even 4000 stimuli were not sufficient for identifying Pa in 1 subject and Nb in 3 subjects. The largest mean peak-to-peak amplitude was the Na-Pa amplitude, but, differences across subjects were large. On the other hand, the BSR-Na amplitude showed relatively small differences across subjects. The BSR latencies were highly stable across subjects. These characteristics indicate that the BSR-Na component is more suitable as an indicator for objective audiometry than either the Na-Pa or Pa-Nb component. The BSR-Na amplitude did not show a decrease as the interstimulus interval was decreased from 104 to 32 ms. On the other hand, the Na-Pa amplitude significantly decreased as the interstimulus interval was decreased from 104 to 42 ms, and the Pa-Nb amplitude also significantly decreased as the interstimulus interval was decreased from 104 to 73 ms. Therefore, because of its resistance to the effects of high rates of stimulation, the BSR-Na component appears to be a suitable audiometric index in the clinical situation where time constraints are a consideration.

Cochlear initiation site of the frequency-following response: a study of patients with sensorineural hearing loss

The cochlear initiation of the frequency-following response (FFR) was assessed by comparing the FFR thresholds to the pure-tone thresholds in four groups of patients suffering from different forms of sensorineural hearing loss. The groups consisted of patients suffering from (1) pure high-frequency hearing losses; (2) high-frequency hearing losses mixed with moderate low-frequency losses; (3) flat hearing losses, and (4)low-frequency hearing losses. Across groups, the pattern of thresholds of the FFR evoked by 500-Hz tome bursts paralleled the pattern of pure-tone thresholds only for the low frequencies- not the high frequencies. In order to clarify the interpretation of this result, a high-pass masking experiment was performed on patients with low-frequency hearing losses. High-pass masking noise did not affect the FFR thresholds to 500-Hz tone burst, but it produced a phase shift of the FFR at stronger intensity levels. The data are interpreted as strongly supporting the view that the FFR at low levels is initiated primarily by activity in the apical portion of the cochlea.

Brain stem response audiometry at speech frequencies

Auditory-evoked brain stem response (BSR; wave V) was studied, using tone pips at three speech frequencies (500, 1 000 and 2 000 Hz) as stimuli. The tone pips consisted of 5-ms rise-decay times without a plateau. BSR recordings were made in 10 normal subjects and in 16 subjects with impaired hearing. In the normal subjects, BSR thresholds ranged from 10 to 20 dB SL at these three frequencies. In the subjects with impaired hearing, BSR thresholds corresponded well to conventional pure-tone thresholds at each frequency in cases of low- as well as high-frequency hearing loss. In all subjects with impaired hearing, the BSR thresholds were higher by as much as 25 dB than the pure-tone thresholds. The mean differences between these two thresholds at 500, 1 000 and 2 000 Hz were 11.3 +/- 8.0, 10.9 +/- 6.2 and 10.9 +/- 7.3 dB, respectively. Thus, we conclude that the BSR is useful for objective assessment of hearing thresholds at each of these speech frequencies.

A case of Gilles de la Tourette's syndrome accompanied with alcoholism

A case of Gilles de la Tourette's syndrome with alcoholism and migraine is described. Multiple motor tics and coprolalia were suppressed by the treatment with haloperidol. The concentration of HVA and 5-HIAA in the cerebrospinal fluid were measured and increment of HVA concentrations was outstanding while his symptoms were aggravated. This might be evidence for hyperactivity of dopaminergic neurons involved in manifest symptomatology of this syndrome.

The effect of onset, offset and rise-decay times of tone bursts on brain stem response

Auditory-evoked brain stem responses (BSRs) were recorded from the scalp in 4 cats and 10 human subjects. Auditory stimuli consisted of 1 kHz tone bursts and their duration, intensity and rise--decay time were varied. The BSR evoked by the tone bursts consisted of on- and off-responses. The off-responses showed different intensity--amplitude and different intensity--latency functions from the on-responses. In the feline subjects, an increase in rise time as an input resulted in an increase in the number of recorded sharp waves of the on-responses, indicating that several cycles of tone bursts during the rise time take part in generating on-responses. In both the feline and human subjects, BSRs were evoked by tone bursts with a rise time of as long as 10 msec; an increase in the rise time resulted in an increased latency and broadened waveforms of the on-responses. These demonstrated properties of BSR may provide useful information in determining input parameters, such as rise--decay time, appropriate for audiometric assessment.

Monoamine oxidase activity in blood platelets in alcoholism

A newly developed assay for monoamine oxidase (MAO) activity in blood platelets was applied in 50 alcoholic patients. The assay is the direct measurement of serotonin oxidation by MAO employing a double microcolumn technique on Sephadex G-10 and Amberlite CG-50 for separating 5-HIAA formed, which is measured fluorimetrically. Rebound of MAO activity levels after withdrawal of alcohol was observed to be more pronounced in the patients with delirium tremens than those who exhibited no outstanding abstinent symptomatology. MAO activity levels measured in the 1st week of alcohol withdrawal were 3.49 +/- 1.15 (Mean +/- S.D) nmol/mg protein/hour in the alcoholic patients with delirium tremens, a value significantly lower than that in the subjects without (p less than 0.01) and that in the male normal subjects (p less than 0.001). Four weeks after withdrawal of alcohol, the reduced MAO activity levels in the alcoholic population were restored to normal levels. These data demonstrate that physical dependency for alcohol occurred evidently in the alcoholic patients examined. Delirium tremens and other psychotic symptoms in alcoholism may be manifested as impaired serotonin metabolism in the brain, which may be due to MAO inhibition caused by excessive alcohol intake.

Reduction of blood platelet monoamine oxidase activity in schizophrenic patients on phenothiazines

A newly developed assay for monoamine oxidase (MAO) activity in blood platelets (serotonin used as substrate) was applied for the measurement of the enzyme activity in 76 schizophrenic patients. No significant reduction was found in the blood platelet MAO activity in a group of 33 untreated schizophrenic patients, as compared to that in the normal controls. Male patients revealed to have lower enzyme activity than females in the schizophrenic group, as we described previously in the normal subjects. Treatment with phenothiazines caused significant reduction of blood platelet MAO activity, while platelet serotonin content and platelet count appeared to be not affected by the drug treatment. The authors suggest that blood platelet MAO activity may be related to hormonal factors but not to psychiatric diagnosis of schizophrenia or constitution liable to schizophrenic illnesses.

An experimental study of intraoral carcinogenesis in rats

A new method has been devised for preparing artificial cecal pouches lined with mucous epithelium in the lower lips of Wistar and Sprague-Dawley rats in order to make carcinogens act continuously for a long time in the oral mucosa. When a 0.5 per cent mineral oil solution of DMBA, a crystal of MC, and a crystal of NG were administered, squamous-cell carcinoma, carcinoma in situ, papilloma, adenoma sebaceum. neurofibroma, fibroma, hemangiosarcoma, hemangiosarcoma, hemangioma, and lymphangioma were successfully produced in the oral mucosa of rats. In addition, interesting findings were obtained concerning tissue changes in the process of carcinogensis in the mucous epithelium.