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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 271 records · Page 15Linked to original sources

[A surgical case of aneurysm of the persistent sciatic artery].

Seventy two-year-old woman was admitted in September, 1985 to our hospital with complaints of painful mass in the right buttock and ischias. Aorto-peripheral arteriogram showed that enlarged right internal iliac and inferior gluteal arteries passed posteriorly to cross the right hip and down the posterior aspect of the femur to supply the popliteal artery. A saccular aneurysm was seen immediately posterior to the right femoral head. The femoral artery was small in size, but connecting to the popliteal artery. Delayed flow to the popliteal artery through the sciatic artery was noted in contrast to the femoral system. With Osborne's right buttock approach, the gluteus maximus muscle was divided in the direction of its fibers, exposing a 3.5 by 5 cm aneurysm which was located above, the sciatic nerve and adherent to it. The proximal sciatic artery and the trunk of the sciatic nerve passed beneath the piriformis muscle. The pressure of the dorsalis pedis artery decreased from 156/77 to 117/72 mmHg after ligation of the proximal sciatic artery. The aneurysm was dissected free from the sciatic nerve. Postoperatively she had no more gluteal discomfort, nor did she have any ischemic symptoms by walking.

Aged↗

Isotype-specific immunoregulation. Evidence for a distinct subset of T contrasuppressor cells for IgA responses in murine Peyer's patches.

The ability of murine Peyer's patch (PP) T contrasuppressor cells (Tcs) to reverse oral tolerance to the T cell-dependent (TD) antigen SRBC was studied both in vivo and in vitro. C3H/HeJ mice given SRBC orally for 4 wk are not rendered tolerant to this antigen and were used as a source of PP Tcs cells for adoptive transfer to identically treated, orally tolerized C3H/HeN mice. Transfer of 10(4) or 5 X 10(4) V. villosa-adherent PP T cells resulted in splenic IgM, IgG, and mainly IgA responses in C3H/HeN mice challenged systemically with SRBC. The T cell responsible was Lyt-1+, 2-, L3T4-, I-JK+ and V. villosa lectin-adherent, all characteristics of mature effector Tcs cells. This C3H/HeJ PP Tcs cell subset was also effective when added to in vitro cultures of tolerized spleen cells derived from SRBC-fed, C3H/HeN mice. Interestingly, C3H/HeJ PP Tcs cells restored mainly IgA responses when transferred in vivo or when added to suppressed C3H/HeN splenic cultures. Comparison of the functional activity of Tcs cells derived from spleen or PP of orally immunized C3H/HeJ mice revealed that splenic Tcs cells supported responses of all 3 isotypes; however, PP Tcs cells yielded three-fourfold higher IgA responses, when compared with IgM or IgG anti-SRBC responses. Adherence of C3H/HeJ PP Tcs to an Fc alpha R+ T cell line derived from IgA-specific Th cells resulted in a nonadherent cell fraction that potentiated only IgM and IgG responses, while bound Tcs cells preferentially supported IgA responses. These results suggest that murine PP contain IgA-specific Tcs cells that allow IgA response induction in the presence of Ts cells that mediate oral tolerance.

Administration, Oral↗

Directional sensitivity of, and neck afferent input to, cervical and lumbar interneurons modulated by neck rotation.

In response to neck rotation of decerebrate, acutely labyrinthectomized cats, interneurons in C4 respond far more frequently to nose-up than to nose down pitch, whereas the reverse is true for interneurons in L3-L4. These directional sensitivities resemble the pattern of extensor excitation in the tonic neck reflex. C4 neurons receiving short latency excitation from the C2 dorsal root ganglion due to intraspinal pathways have a distribution of directional sensitivities to pitch stimuli that is similar to that of the whole population. The directional sensitivities of C4 neurons with late excitation, which may be due to supraspinal loops, are more broadly distributed.

Animals↗

Induction of nonspecific cell-mediated cytotoxic reactivity from non-immune spleen cells treated with aloctin A.

Culturing of mouse spleen cells with aloctin A (Alo A), a lectin having anti-tumor activity, resulted in the induction of cells cytotoxic to syngeneic and allogenic tumor cells in vitro. Alo A-induced killer cells could be generated from spleen cells of natural killer cell-deficient beige mice but not from those of T cell-deficient nude mice. The results of cytotoxicity assay after treatment with antisera plus complement indicated that the killer cells mainly consisted of Thy 1+, Lyt 1-2+, asialo GM1(1)-T cells. Their cytotoxic activity was markedly augmented by the presence of Alo A during the assay for cytotoxicity. The assay of IL2 in the culture fluid from Alo A-treated spleen cells and the effect of dexamethasone (DEX) on IL2 production from Alo A-stimulated spleen cells and on generation of killer cells suggested that generation of Alo A-induced killer cells was closely associated with the amount of IL2 released from the spleen cells in culture.

Animals↗

Augmentation of lymphokine-activated killer cell activity in vitro by aloctin A.

Culturing of mouse spleen cells with IL2-containing MLA144 conditioned medium (MLA144 CM) resulted in the induction of cells cytotoxic to syngeneic and allogeneic tumor cells in vitro. The cytotoxicity was markedly augmented by the presence of aloctin A (Alo A), a lectin having anti-tumor activity, during the assay for the cytotoxicity. The results of cytotoxicity assay after treatment with antisera and complement indicated that the killer cells mainly consisted of Thy 1+, Lyt 1-2-, asialo GM1-T cells.

Animals↗

Spatial organization of neck and vestibular reflexes acting on the forelimbs of the decerebrate cat.

EMG recording was used to study the spatial organization of vestibular and tonic neck reflexes acting on forelimb and shoulder muscles of the decerebrate cat. Neck reflexes were studied in preparations with intact labyrinths as well as those with acute or chronic labyrinthectomies. Reflexes were described by response vectors whose orientation component is aligned with the optimal excitatory direction of tilt or head rotation. A muscle's vector orientation remained reasonably stable over a period of hours, although there was sometimes drift at the beginning or end of an experiment. Orientation of muscle response vectors did not change systematically with stimulus frequency of 0.05-2.0 Hz. For vestibular reflexes this is so, although their dynamics are consistent with convergent input from semicircular canals and otolith organs. Regardless of the preparation, a consistent reflex pattern emerged. Vestibular reflexes are characterized by response vector orientation near ear-down roll. Neck vector orientation lies in the opposite direction from the vestibular vector but typically lies further from the roll plane: Nose-up pitch is excitatory for the shoulder muscles supra- and infraspinatus, and for the medial and lateral heads of triceps, whereas nose-down pitch excites the long head of triceps. Our results generally agree with the pattern proposed by Roberts (28) for neck reflexes but disagree in part with his proposed pattern of vestibular reflexes; we did not see the expected consistent excitation by nose-down pitch.

Animals↗

Responses of interneurons in the cat cervical cord to vestibular tilt stimulation.

The responses of interneurons in the cervical spinal cord of the decerebrate cat to whole-body tilt were studied with a goal of identifying spinal elements in the production of forelimb vestibular postural reflexes. Interneurons both in the cervical enlargement and at higher levels, from which propriospinal neurons have been identified, were examined, both in animals with intact labyrinths and in animals with nonfunctional semicircular canals (canal plugged). Most cervical interneurons responding to tilt respond best to rotations in vertical planes aligned within 30 degrees of the roll plane. Two to three times as many neurons are excited by side-up roll tilt as are excited by side-down roll. In cats with intact labyrinths, most responses have dynamics proportional either to (and in phase with) the position of the animal or to a sum of position and tilt velocity. This is consistent with input from both otolith organs and semicircular canals. In animals without functioning canals, the "velocity" response is absent. In a few cells (8 out of 76), a more complex response, characterized by an increasing gain and progressive phase lag, was observed. These response dynamics characterize the forelimb reflex in canal-plugged cats and have been previously observed in vestibular neurons in such preparations.

Animals↗

Induction of alkaline phosphatase activity in murine spleen cells treated with various mitogens.

The correlation between murine lymphocytes blastoid transformation and alkaline phosphatase (AL-P) activity was examined. When murine spleen cells were stimulated with lipopolysaccharide, a B cell mitogen, for 48 h, the AL-P activity was induced in a dose dependent manner. Similarly, stimulation of the spleen cells with Concanavalin A (Con A), a T cell mitogen, induced the AL-P activity. However, when the thymocytes were treated with Con A, only the [3H]dThd uptake was increased. Other B cell mitogens, such as lipid A and fungal B cell mitogens, and T cell mitogen, Pusum sativum agglutinin (PSA) also induced the AL-P activity of spleen cells. Kinetics of [3H]dThd uptake and induction of AL-P was similar. Correlation coefficients between [3H]dThd uptake and AL-P activity were r = 0.98789, p less than 0.01 for LPS, r = 0.99530, p less than 0.01 for lipid A and r = 0.62595, p less than 0.001 for the fungal B cell mitogens. The AL-P activity of the spleen cell was also induced by treatment with Con A sup, which was a supernatant fluid prepared by spleen cell cultured with Con A for 48 h, containing various lymphokines. These findings suggest that the AL-P activity was induced in the case of B lymphocyte blast transformation when stimulated directly with B cell mitogen or indirectly via lymphokines with T cell mitogen. Measurement of the AL-P activity would be a useful method to assay murine blastoid lymphocytes.

Alkaline Phosphatase↗

Antitumor activity of a beta-1,3-glucan obtained from liquid cultured mycelium of Grifola frondosa.

The antitumor activity of a branched beta-1,3-glucan "grifolan LE" purified from liquid cultures of Grifola frondosa (Ohno et al. Chem. Pharm. Bull., 34, 1709-1715 (1986] was examined on an allogeneic murine tumor system. By intraperitoneal (i.p.) administration (100-200 micrograms/mouse/d X 5) at days 1 to 9 from the tumor transplantation, grifolan LE showed marked inhibitory activity on the growth of solid form sarcoma 180 in ICR mice. Significant activity was also observed in intravenous (i.v.) or intratumoral (i.t.) administrations. However, the oral (p.o.) administration of grifolan LE was not effective. I.p. administration of grifolan LE at a dose of 100 micrograms/mouse/d X 5 before the tumor transplantation showed significant inhibition of tumor growth. I.p. administration of grifolan LE at day +11 to +19 was also effective. Grifolan LE was not effective on the ascites form of sarcoma 180. The pretreatment of sarcoma 180 cell with grifolan LE in vitro did not affect tumor growth. The mice cured from the solid form of sarcoma 180 by administration of grifolan LE had the ability to reject the same tumor cell. From these results, it is suggested that the antitumor activity of grifolan LE occurred by modification of biological responses.

Animals↗