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Biomedical subjects

N Inamura

Publications and source records attributed to N Inamura.

At least 91 records · Page 5Linked to original sources

FK-506, a novel immunosuppressant isolated from a Streptomyces. II. Immunosuppressive effect of FK-506 in vitro.

The immuno-pharmacological profile of a novel immunosuppressive agent, FK-506 produced by a streptomycete, is presented here. We proceeded to test the effect of the agent on various in vitro immune systems. It showed that mixed lymphocyte reaction, cytotoxic T cell generation, the production of T cell-derived soluble mediators such as interleukin 2 (IL-2), interleukin 3 and gamma-interferon and the expression of the IL-2 receptor were suppressed by this agent. The IC50 values of FK-506 and ciclosporin (CS) in all tests were approximately 0.1 nM and 10 nM, respectively. Therefore, the novel agent, FK-506 suppressed in vitro immune systems at about hundred times lower concentration than CS.

Animals↗

Gas analysis of the middle ear cavity in normal and pathological conditions.

The gas of the tympanic bulla was measured using 18 normal and 14 tube-obstructed guinea pigs. The concentrations of CO2 and O2 were 4.8 +/- 1.0% and 7.2 +/- 1.8% in normal animals, and 4.3 +/- 1.6% and 8.1 +/- 2.0% in tube-obstructed animals, respectively. The bulla was opened to room air and then closed again. The recovery process of each gas was examined. In normal animals, CO2 and O2 were exponentially changed toward the pre-open value with time. The time constants of this recovery process were 15 min and 97 min in CO2 and O2, respectively. In tube-obstructed animals, however, this quick recovery of CO2 was significantly delayed (time constant, 50 to 80 min), although there was no effect upon the recovery of O2. This delayed recovery of CO2 is likely to be due to the edema of the mucous membrane.

Animals↗

Atelectatic ear and pathologic nasopharynx.

Pathologic relation between atelectatic ears and their nasopharynx were investigated in 50 patients with various degrees of atelectatic ears by transnasal fibrescope and C.T. And their morbid adenoids were compared with the adenoids of 20 patients with mouth breathing but free from ear problems. The process of drum bulging after catheterization, retraction after inflation, and inward movement during swallowing, proved that intratympanic pressure was influenced by nasopharyngeal pressure produced by swallowing, and that Eustachian tube itself was functioning to the pressure. Intratympanic negative pressure was proved by the movement of blue solution after the puncture of 5 atelectatic ear with effusion. And more dynamic negative pressure produced by swallowing was demonstrated in 5 other cases. The morbid adenoid with atelectatic eardrum was differentiated from the large posterior type of adenoid of the healthy eardrum, by the pendulous projection over the choana especially in swallowing. A dynamic vacuum caused by "Toynbee phenomenon" is discussed.

Adenoids↗

Studies of an immunomodulator, swainsonine. II. Effect of swainsonine on mouse immunodeficient system and experimental murine tumor.

We examined the effect of swainsonine on antibody response to sheep red blood cells (SRBC) in immunodeficient mice which were treated with immunosuppressive factor or antitumor drugs, or inoculated with sarcoma 180 ascites tumor. The administration of swainsonine restored the capacities of the immunodeficient mice to produce antibody against SRBC. Furthermore, swainsonine inhibited completely the growth of sarcoma 180 ascites tumor in mice. Swainsonine also reduced lung metastases of B16 melanoma in mice. These results suggest that swainsonine has potential as an immunomodulator for the treatment of immunocompromised hosts.

Adjuvants, Immunologic↗

Activation of tumoricidal properties in macrophages and inhibition of experimentally-induced murine metastases by a new synthetic acyltripeptide, FK-565.

The effect of FK-565, a novel low molecular weight (MW) acyltripeptide, on tumoricidal properties of murine macrophages is reported here. Peritoneal macrophages (PMs) harvested from C57BL/6 mice and beige mice were rendered cytotoxic to syngeneic B16 melanoma cells following their interaction in vitro with FK-565. Maximal and reproducible activation of tumoricidal properties in PM were obtained by interaction in vitro with 25 micrograms/ml of FK-565 for a 24 h period, and as little as 0.5 microgram/ml of FK-565 was sufficient to induce significant cytotoxicity. Murine PMs activated by FK-565 in vitro were cytotoxic to syngeneic and xenogeneic tumor cells, but did not affect allogeneic nontumor cells. The PMs were also activated to kill B16 melanoma cells by intraperitoneal injections of FK-565 (10 mg/kg). Multiple injections of FK-565 into mice also slightly but significantly inhibited lung metastases. These results suggest that FK-565 has potential as an effective immunopotentiator in immunotherapy.

Adjuvants, Immunologic↗

Effect of kainic acid upon N1 latency.

Although the N1 latency of whole nerve action potential is one of the important pieces of information obtained from ECochG, there are some conflicting opinions as to whether or not it is prolonged in sensorineural hearing loss. Kainic acid (KA) is known to destroy neurons selectively through an action at glutamatergic synapses. Therefore, a model of "neural deafness" was made by perfusing the scala tympani with KA solution. The effect of KA upon cochlear microphonics was minimal. Although the N1 amplitude was markedly suppressed by KA, the N1 latency was neither prolonged nor shortened. The result obtained in the present study strongly suggests that the N1 latency is not prolonged in "neural deafness."

Animals↗

Effect of hypothermia upon the electrocochleogram and auditory evoked brainstem response.

The effects of hypothermia upon electrocochleogram (ECochG) and auditory evoked brainstem response (ABR) were studied in 10 children who underwent the open heart surgery under hypothermic anesthesia. The latencies of N1, waves III and V in response to click of 115 dB p.e. SPL were prolonged at the rate of 0.12 +/- 0.02, 0.25 +/- 0.04 and 0.43 +/- 0.05 msec/degree C, respectively. The N1 amplitude was initially increased, returned to the precooling value at about 26 degrees C and decreased thereafter. SP was increased in amplitude by hypothermia and never disappeared throughout the observation. At the time of rewarming, SP appeared first, followed by N1 and finally by waves III and V. The results obtained in the present study were discussed in the light of the sensitivity of the sensory hair cells, peripheral nerves and CNS to the hypothermic condition.

Anesthesia, General↗

Potentiation of tumoricidal properties of murine macrophages by Nocardia rubra cell wall skeleton (N-CWS).

Intraperitoneal injection of squalene-treated cell wall skeleton of Nocardia rubra (N-CWS) caused increase in number of peritoneal exudate cells (PEC). Adherent macrophages obtained from N-CWS-treated PEC suppressed growth of methylcholanthrene-induced fibrosarcoma (Meth-A), when injected intradermally with the tumor cells into BALB/c mice. The macrophages showed strong cytotoxicity against Meth-A cells in vitro. When treated with 10 micrograms/ml of N-CWS in vitro, proteose peptone-induced macrophages acquired tumoricidal property but resident macrophages showed no cytotoxicity after the treatment. In the supernatant of spleen cells cultured for 72 hours in the presence of N-CWS (10 micrograms/ml), the presence of (a) factor(s) with macrophage activating effect was observed. This factor, shown to be identical to macrophage activating factor (MAF) in molecular weight, showed synergy with N-CWS in potentiating macrophage cytotoxicity against tumor cells.

Adjuvants, Immunologic↗