Supersensitivity of cortical neurones of the rat to acetylcholine and L-glutamate following chronic morphine treatment

Summary The effect of microelectrophoretically applied L-glutamate and acetylcholine on discharge activity of cortical neurones was studied in naive and in morphine-tolerant/dependent rats. The thresholds for increase in discharge activity elicited by these 2 putative neurotransmitters were 3 times lower in the tolerant/dependent rats than in the naive rats, indicating the development of supersensitivity.     

Automatic detection of rapid eye movements by discrete wavelet transform

In order to detect rapid eye movements (REM) automatically, the Discrete Wavelet Transform was applied to each 8-s segment of electrooculogram (EOG) data for 30 min of 8 h of normal sleep. The Haar function was used as an analysing wavelet because this function is similar to the REM waveform. By shifting the phase of the analysing wavelet by pi/4 of the function, 96% of REM could be detected. The artifacts caused by body movements could be detected simultaneously by this method. Computing time required for the detection of REM was only 11 s for 30 min EOG data.     

New technique for producing hybridoma by using laser radiation

BACKGROUND AND OBJECTIVE: With conventional methods, cell fusion rate is extremely low, and fusion of two specific cells is not possible. We developed a new method for inducing cell fusion under the microscope by using a microprocessing device by laser. STUDY DESIGN/MATERIALS AND METHODS: Under a microscope, the target cells were irradiated with laser beams for trapping. Then, the trapped cells were transferred and placed in contact with the corresponding cells, which were also fixed by laser beam. The pulse laser beams are focused on the contact surface to cut small perforations for mutual communication of the cytoplasms. RESULTS: The fusion rate of mouse myeloma cells was 38%. The rate of hybridoma production of myeloma cell and lymphocyte was 2%. We confirmed the proliferation of the newly formed hybridoma in HAT medium and the production of immunoglobulin G. CONCLUSION: This new cell fusion method is characterized by production of hybridomas of target cells, lower cell toxicity, and a high rate of hybrid production.     

Measurement of protein C inhibitor in seminal plasma is useful for detecting agenesis of seminal vesicles or the vas deferens

Protein C inhibitor (PCI), a plasma serine protease inhibitor of activated protein C, is present at high concentrations in the seminal plasma of normal subjects and is decreased in some infertile patients. We measured the concentrations of PCI, prostate-specific antigen, and fructose in the seminal plasma of infertile patients (n = 125) and of normal subjects (n = 13). We also measured time-dependent changes in the concentrations of PCI and fructose in seminal plasma after ejaculation. A weak correlation was found between the levels of PCI and fructose (r = 0.268, P = 0.016). The PCI level in seminal plasma of patients with seminal vesicle and/or vasal agenesis was significantly lower (P < .01) than in normal subjects. The level of fructose in seminal plasma decreased in vitro in a time-dependent manner after ejaculation, whereas the concentration of PCI was stable at 48 hours after ejaculation. These data suggest that PCI in seminal plasma, as well as fructose, may become one of the markers for agenesis of seminal vesicles and/or the vas deferens.     

Prediction of nodal metastasis by comparative genomic hybridization in biopsy specimens from patients with superficial esophageal squamous cell carcinoma.

PURPOSE: Selection of appropriate protocols for treatment of superficial esophageal squamous cell carcinoma (SESCC) is dependent on lymph node metastasis status. Therefore, it is important to know whether lymph node metastasis is present before treatment. EXPERIMENTAL DESIGN: In this study, we examined the relation between DNA sequence copy number aberrations detected by comparative genomic hybridization and lymph node metastasis in 26 surgically resected SESCCs (training samples). We then assessed whether the genetic information is predictive for nodal status in biopsy specimens from eight newly enrolled patients with SESCC (blinded samples). RESULTS: Pathological examination revealed that 17 of 26 training samples (65.4%) did not have associated lymph node metastasis. Gains of 8q24 and/or 20q12-qter were observed in 12, including all (nine of nine) with nodal metastasis. Fourteen training samples did not have gain of either 8q24 or 20q12-qter. Of the blinded samples, two showed no gain of 8q24 or 20q12-qter, and as anticipated the postoperative pathological examination revealed no nodal metastasis. The remaining six blinded samples had gains of 8q24 and/or 20q12-qter, and lymph node metastasis was detected by postoperative examination in four of these tumors. CONCLUSIONS: Absence of gains of 8q24 and/or 20q12-qter appears to be associated with absence of lymph node metastasis in patients with SESCC; therefore, less invasive surgery can be chosen.     

A case of urinary stone in ureterocele extracted transurethrally after ESWL

A 66-year-old man was referred to our hospital with chief complaints of difficulty in urination and terminal micturition pain. Ureteroceles were identified bilaterally, and a ureteral stone (19 x 12 mm) existed in the right ureterocele. After crushing the stone by extra corporeal shock wave lithotripsy (ESWL), we removed the stone transurethrally with a small incision in the right ureterocele. The vesicoureteral reflux (VUR) was not detected postoperatively. Now, we recommend the combination of ESWL and a small transurethral incision of the urelerocele for the treatment of ureteral stones in a ureterocele in order to prevent postoperative VUR.     

Localization of calcitonin receptor mRNA in the mouse brain: coexistence with serotonin transporter mRNA

To elucidate the sites of and mechanisms of analgesic effect of centrally injected calcitonin, we examined expression of calcitonin receptor mRNA in the mouse brain by in situ hybridization techniques. Calcitonin receptor mRNA was expressed in various brain regions, including the preoptic area, dorsomedial hypothalamic nucleus, lateral hypothalamic area, periaqueductal gray, dorsal raphe nucleus, locus coeruleus, lateral parabrachial nucleus, gigantocellular reticular nucleus alpha part, lateral paragigantocellular nucleus, raphe magnus nucleus and solitary tract nucleus, which are known to play important roles in pain modulation. In addition, a double in situ hybridization technique demonstrated the intense expression of calcitonin receptor mRNA on serotonergic neurons in some raphe nuclei and the lateral paragigantocellular nucleus, suggesting the involvement of central serotonergic pathways in analgesic effect of calcitonin.     

Organophosphates and their impact on the global environment

Serious intoxications and incidences due to misuse of organophosphorus insecticides (OP) have been reported for over three decades. In this meeting I am talking about the following three topics. (1) Epidemiological studies on the use of OP in Japan, Taiwan and Thailand. The National Research Institute of Police Science (NRIPS) in Japan has published the annual report of the epidemiological studies on the criminal and suicide events. The numbers of the incidence of pesticides are approximately 22%-30% of the total incidences, during 1991 and 1996. The incidence of pesticides has been gradually reduced for past six years. This seems to be influenced by the decrease of the incidences of paraquat having extremely high toxicity. According to the epidemiological data in the National Poison Center in Taiwan, unlike the prevalence of drug poisoning exposures in most western countries, pesticides poisoning exposures are numerous in Taiwan. The number of pesticide intoxication cases is 6,872 out of 23,436 of total case numbers of various intoxications during the 1985 and 1997. The fatality rate is much higher in Taiwan than in most western countries, with 5.65% of all poisoning exposures resulted in death. Paraquot is the leading cause of death in Taiwan. The ratio of death to total OP intoxication cases is 11.5% including accidental exposure and suicide. According to the report of the Division of Epidemiology, Ministry of Public Health, Thailand during the 1990-1995, the overall morbidity due to poisoning was 30 per 100,000 population with 300 deaths per year. The morbidity rate of reported pesticide poisoning in the whole country was 10 per 100,000 population. (2) Sarin victims in Tokyo. On March 20, 1995, a terrorist attack using sarin (isopropylmethylphosphonofluoridate) occurred on the Tokyo subway. Many people inhaled the sarin gas and collapsed in the train. Eventually, 12 people died and over 5,000 were injured. The results of the forensic studies showed that methylphosphonic acid, the hydrolysis product of sarin, bound to AChE in the cerebellums of the victims was separated and identified using GCMS. (3) A sensitive and rapid biomarker of OP-poisoning. Beta-glucuronidase (beta-G) is loosely bound to egasyn which is one of carboxylesterase isozymes in the liver microsomes. The oxon formed from OP in the liver microsomes is covalently bound to egasyn and causes the cleavage of the egasyn-glucuronidase complex, leading to the release of beta-G into the blood. In fact, plasma beta-G activities is a much more sensitive and rapid biomarker than the blood cholinesterase inhibition. In conclusion, OPs cause serious toxicity in both acute and chronic exposures. The epidemiological data in Taiwan and Thailand show that paraquat intoxication cause the most serious irreversible damage in the patients. In 1995, terrorists attack using sarin which is one of the most toxic OP, on the Tokyo subway, and 12 people died. This is an example of the acute intoxication of OP and some people have been still in hospitalized. Recently, the present authors have reported that the plasma beta-G activity is a novel biomarker of OP intoxication. The plasma beta-G is rapidly and significantly increased after OP exposure, and this is a much more sensitive to OP intoxication than ChE inhibition.     

Sound-induced laryngeal and respiratory reflexes originate from vestibular afferents

To determine whether the auditory or vestibular system causes the sound-induced laryngeal reflex, which has been considered to participate in the auditory feedback control of vocalization, click-induced laryngeal responses were compared before and after sectioning of the cochlear and/or vestibular nerves in cats. The sound-induced reflex modulation of respiratory muscle activity was also investigated, because respiratory movement is important for vocal control. Sectioning of the cochlear nerves had little influence on these responses. In contrast, sectioning of the vestibular nerves abolished these responses. It was concluded that the sound-induced laryngeal and respiratory reflexes are attributed to the vestibular system.