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Biomedical subjects

J Tanaka

Publications and source records attributed to J Tanaka.

At least 685 records · Page 38Linked to original sources
PubMed1987

Lateral hypothalamic region excites the activity of vasopressin neurons in the supraoptic nucleus through subfornical organ neurons.

In urethane-anesthetized male rats, microinjection of angiotensin II into the lateral hypothalamic area excited the activity of about half (N = 7) of subfornical organ neurons (N = 15) antidromically identified as projecting to the hypothalamic supraoptic nucleus. Microinjection of angiotensin II also excited the activity of approximately one-quarter (N = 8) of putative vasopressin-secreting neurons (N = 28) in the hypothalamic supraoptic nucleus and these excitatory responses of putative vasopressin-secreting neurons were blocked (N = 3) or attenuated (N = 3) by pretreatment with the angiotensin II antagonist saralasin, but not by isotonic saline (N = 2), in the subfornical organ.

Action Potentials↗
PubMed1987

Establishment and biological characterization of an in vitro human cytomegalovirus latency model.

In an attempt to develop an in vitro human cytomegalovirus (HCMV) latency model system, the growth characteristics of HCMV in a human thyroid papillary carcinoma cell line (TPC-1) were examined. When TPC-1 cultures preheated at 40.5 degrees for 48 hr were infected with HCMV and incubated at a supraoptimal temperature (40.5 degrees), the cultures could be maintained for at least 65 days without detection of infectious virus. In contrast, when the infected cultures were incubated at 37 degrees, HCMV persistently infected cultures were established. HCMV was reactivated from the latently infected cultures by decreasing the incubation temperature from 40.5 to 37 degrees, and the cultures subsequently entered into virus persistent infection. Although HCMV-specific polypeptides which comigrate with the immediate early virus polypeptides and nuclear antigens were continuously detectable in the majority (more than 95%) of the cells during the latent period, a detectable level of virus-specified DNA polymerase (one of the early virus proteins) was not induced, suggesting that the blockage of HCMV replication in the latently infected cultures occurs at the early stages of the HCMV replication cycle. Infectious center assay revealed that 0.002 to 0.2% of the cells contain an HCMV genome that can be activated during the latent period. The latently infected cells were susceptible to superinfection with homologous and heterologous strains of HCMV. In persistently infected cultures approximately 38% of the cells were lysed by reaction with HCMV immune serum and complement, whereas complement-mediated immune cytolysis could not be detected in the latently infected cultures. The data presented suggest that a temperature-sensitive cellular function(s) that controls the expression of the HCMV early functions plays an important role in maintenance of the HCMV genome in the latent state and reactivation of HCMV by decreasing the incubation temperature.

Antigens, Viral↗
PubMed1987

Subfornical organ neurons act to enhance the activity of paraventricular vasopressin neurons in response to intravenous angiotensin II.

The effects of pretreatment of the angiotensin II (ANGII) antagonist, saralasin (Sar), in the subfornical organ (SFO) on intravenous ANGII-induced responses of the activity of phasically firing paraventricular nucleus (PVN) neurons (n = 23) antidromically identified as projecting to the posterior pituitary were examined in urethane-anesthetized rats. The activity of the majority (n = 18) of identified PVN neurons was excited by intravenously administered ANGII, whereas the remaining neurons (n = 5) were not affected. The excitatory responses (n = 13) to ANGII were prevented by pretreatment with Sar, but not by isotonic saline (n = 3), in the SFO. These results suggest that ANGII-sensitive SFO neurons may act to enhance the excitability of putative vasopressin (VP)-secreting neurons in the PVN in response to circulating ANGII.

Action Potentials↗
PubMed1987

Contribution of monoaminergic nervous system in potentiation of 2-sec-butylphenyl N-methylcarbamate (BPMC) toxicity by malathion in male mice.

Malathion-induced marked potentiation of BPMC toxicity (about fivefold) was analyzed by measuring LD50 as an index of acute toxicity. The acute lethality of BPMC was decreased by muscarinic blockers (atropine, methylatropine, or trihexyphenidyl) or a monoamine oxidase inhibior (pargyline) and increased by a monoamine depleter (reserpine) or a dopaminergic blocker (haloperidol). The potentiation observed with BPMC and malathion was decreased by the muscarinic blockers, monoamine depleters (reserpine, alpha-methyl-p-tyrosine), an alpha-noradrenergic blocker (phentolamine), or haloperidol. The acute toxicities of other N-methylcarbamates MPMC (3,4-dimethylphenyl N-methylcarbamate), MTMC (3-methylphenyl N-methylcarbamate), NAC (1-naphthyl N-methylcarbamate), and XMC (3,5-dimethylphenyl N-methylcarbamate) were potentiated by malathion to a lesser degree than that of BPMC. Atropine protected against the lethalities of all N-methylcarbamates. Reserpine or haloperidol potentiated the lethalities of N-methylcarbamates with a similar tendency toward malathion. When the inhibitory effect of each N-methylcarbamate on brain acetylcholinesterase (AChE) was compared with its LD50, among five N-methylcarbamates BPMC had particularly strong anti-AChE activity. This characteristic of BPMC was not observed after the treatment with reserpine. These results suggest that BPMC may act not only on cholinergic nerves as an anti-AChE, but also on monoaminergic nerves which antagonize the lethal cholinergic effect. Malathion might inhibit the effect of BPMC on the monoaminergic nerves, thereby markedly potentiating the lethal effect of BPMC.

Acetylcholinesterase↗
PubMed1987

Influence of microinjection of glucagon into ventromedial hypothalamus on acetate metabolism in liver slices of rabbit.

Glucagon was injected directly into the ventromedial hypothalamic nuclei (VMH) of rabbits, and changes in hepatic acetate metabolism were studied. The injection of 3 ng glucagon into the VMH of intact rabbits increased the rates of 14C transfer from 14C-1-acetate into CO2, glucose and ketone bodies but decreased those into cholesterol ester, triglyceride, free cholesterol, free fatty acids and phospholipids. However, after glucagon injection into the VMH of rabbits with VMH lesions and the parietal cortex of intact rabbits, hepatic acetate metabolism did not differ from that of the control rabbits, which received saline injection into the same brain regions. These observations support the hypothesis that the VMH are parts of a glucagon-sensitive brain regulator system in the hepatic acetate metabolism.

Acetates↗
PubMed1987

Multiple system atrophy with retinal degeneration in a young child.

A 4-year-old girl with multiple system degeneration and retinal degeneration was presented. There was onset of an ataxic gait at two years and rapid progression of retinal degeneration, myoclonus and cranial nerve palsy. Neuropathological examination revealed severe degeneration of the cerebellar cortex and the pathways of auditory and deep sensation, as well as degeneration of the cerebellar efferent fibers, the striatonigral system, the cerebellar afferent fiber system and lower motor neurons. Cases of young children with spinocerebellar degeneration have been reported in several families of olivopontocerebellar atrophy (OPCA), but degenerative changes in our case were more widespread than those in OPCA cases. The multiple system lesions in the central nervous system and retina of this child are different from those of any other previously reported cases.

Brain Stem↗
PubMed1987

Incontinence in female neurogenic bladders. Resolution by endoscopic bladder neck suspension.

Five incontinent females with neurogenic bladder diseases underwent endoscopic vesical neck suspension (Stamey procedure). Four patients have become dry on clean intermittent catheterisation and one has shown improvement. Bladder capacity was increased to a reasonable size in all patients. There has been no upper tract deterioration during the follow-up period of 3 to 25 months. We believe that the Stamey procedure is useful in alleviating urinary incontinence in neurogenic bladders provided that the bladder is drained regularly by intermittent catheterisation and that low detrusor compliance or detrusor hyper-reflexia is adequately managed.

Adolescent↗
PubMed1987

[A study on subjective symptoms of fatigue in gainfully occupied couples].

The number of gainfully occupied couples has been increasing. A survey on the subjective symptoms of fatigue and on life and work was carried out on 996 personnel belonging to a university hospital in order to ascertain their fatigue pattern and the following results were obtained. 1. Both the husbands and wives showed II-dominant type (mental-work type, night-work type) among the three types classified by subjective symptoms. 2. When compared with the results of our previous survey, though T value was not so high, II/T value was high and III/T value was low in both groups of husbands and wives, suggesting a marked tendency of mental fatigue. 3. Difference in complaint rate of fatigue between pre- and post-work in the group of husbands was smaller than that in the group of wives, suggesting that the group of husbands is slower in recovery from fatigue after work. 4. The level of physical activity at work and the amount of physical work such as caring of children and housekeeping was higher in wives, while the husband's work is mental and the amount of physical work is relatively small. Thus, wives appear to recover faster from mental fatigue. It is considered that husbands need to improve their manner of spending their free time. 5. The results of regression analysis on the complaint rate in wives and husbands showed that there is a correlation between the complaint rate of wives and that of their husbands. Therefore, as a counter-measure to fatigue, improvement of life pattern outside of working time is important as well as that of work.

Adult↗
PubMed1987

[Multimodality treatment of nasopharyngeal carcinoma].

In the treatment of nasopharyngeal carcinoma (NPC), radiation has been the treatment of choice, because it is effective for locoregional disease. However, the results of radiotherapy for NPC have revealed that local relapse and/or distant metastases occur frequently, and consequently the five-year survival rate is as low as around 30%. Since 1982, we have adopted chemotherapy initially applied prior to radiotherapy (= pre-radiation chemotherapy) for the treatment of NPC in order to achieve better results. The chemotherapy mainly consists of a combination of cisplatin and peplomycin. Twenty-one previously untreated patients with NPC were evaluable. Three complete and fifteen partial remissions were achieved, with an 86% response rate to the chemotherapy. The treatment involving a combination of pre-radiation chemotherapy and radiotherapy resulted in local relapse in one patient and distant metastases in two patients with an 87.5% survival rate according to the Kaplan-Meier method. Immunotherapy is also indispensable in the treatment of NPC. Our present multimodality treatment for NPC consists of a combination of pre-radiation chemotherapy and radiotherapy followed by long-term administration of a biologics such as OK-432.

Adolescent↗
PubMed1987

[Multidisciplinary treatment of carcinoma of the oropharynx].

From 1963 through 1986, we examined 91 patients with carcinoma of the oropharynx. Of these 91 patients, the primary treatment modality was chosen for 75 patients. The patients were divided into 2 groups according to the periods of treatment. In group I (1963-1973), 33% of the patients were applied combined radiotherapy and chemotherapy, and 28% chemotherapy followed by surgery as their initial treatment. In group II (1974-1986), 65% of the patients were applied combined radiotherapy and chemotherapy, and 21% a multimodal treatment consisting of radiotherapy combined with chemotherapy followed by composite resection. Five-year survival rate was 36% in group I and 51% in group II, which indicated a progress in the treatment of carcinoma of the oropharynx. The role of surgical treatment for carcinoma of the oropharynx was discussed. It appears that composite resection and reconstructive surgery produced a great benefit in the treatment of residual diseases after radiotherapy or recurrent diseases. Then our new treatment modality incorporating neo-adjuvant chemotherapy was presented. The literatures in terms of neo-adjuvant chemotherapy were reviewed.

Adult↗
PubMed1987

Pathophysiology of acute renal failure following living Escherichia coli injection in rats: high-energy metabolism and renal functions.

The energy metabolism of kidney and renal function were studied in rats following an IV injection of living Escherichia coli. Energy charge (ATP + 0.5 ADP/ATP + ADP + AMP) decreased throughout the period studied. Total and ouabain-sensitive Na-K ATPase activity of renal cortex homogenate decreased markedly at 3 hr followed by gradual recovery. Polyulia was seen at 3 and 6 hr followed by oliguria at 12 hr after E. coli injection. PSP excretion test showed a marked decrease throughout the time course. In contrast, creatinine clearance decreased only at 12 hr. From these results, it was clarified that the renal insufficiency following bacteremia occurs in two different stages; the early stage with a high urinary output accompanied by decreased Na-K ATPase activity suggesting deterioration of proximal tubular functions and the late stage with oliguria in which glomerular filtration is severely depressed. In both stages, renal energy metabolism is markedly disturbed.

Acute Kidney Injury↗
PubMed1987

[A case of giant vesical diverticulum with malignant neoplasm].

We experienced a case of giant vesical diverticulum with a malignant neoplasm in which the preoperative diagnosis was difficult. It simultaneously occurred with a vesical tumor. The patient, a 68-year-old man, visited our hospital complaining of pollakisuria, nycturia and microscopic hematuria. He had urinary retention and his vesical urine volume was 1,450 ml. X-ray examination and ultrasound examination revealed a giant vesical diverticulum and moderate hypertrophy of the prostate. A vesical tumor was suspected. Cystometrogram revealed a flaccid pattern with vesical capacity over 900 ml. Diverticulectomy and resection for a vesical tumor were performed. A malignant neoplasm in the vesical diverticulum was found during the operation. Transurethral resection of the prostate was performed after two months. There has been no evidence of recurrence for 3 years postoperatively.

Aged↗