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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 289 records · Page 16Linked to original sources
PubMed1986

Growth of Lactobacillus bulgaricus in milk. 2. Characteristics of purine nucleotides, pyrimidine nucleotides, and nucleic acid synthesis.

Lactobacillus bulgaricus incorporated exogenous guanine only into guanine nucleotides and not into adenine nucleotides. Lactobacillus bulgaricus lacks the ability to interconvert adenine nucleotides and guanine nucleotides. Biosynthesis of pyrimidine nucleotides from orotic acid was depressed by addition of guanosine monophosphate or adenosine monophosphate. Some step in pyrimidine biosynthesis from orotic acid may be negatively regulated by the intracellular amount of purine nucleotides. Lactobacillus bulgaricus could not grow in milk from which orotate was removed. This indicates that the activity of de novo pyrimidine synthesis is very low in this organism. When the intracellular amount of purine or pyrimidine base was limited, ribonucleic acid synthesis was markedly depressed, resulting in cell elongation, whereas deoxyribonucleic acid synthesis was not so much affected.

Adenine↗
PubMed1986

[Evaluation of plasma carcinoembryonic antigen (CEA) in patients with head and neck cancer: correlation with tissue CEA staining].

Forty-five patients with head and neck cancer were the subjects of the study. In most cases, plasma CEA was low and could not provide a significant clinical monitor. Two patients with poorly differentiated epidermoid carcinoma had low plasma CEA levels at the pretreatment stage, but after treatment, the levels tended to be higher because of distant metastasis. Tow other cases exhibiting undifferentiated carcinoma of the maxillary sinus at the pretreatment stage had abnormally high plasma CEA levels of 160 ng/ml and 46 ng/ml. These two patients proved the value of the correlation with cancer therapy and recurrence.

Carcinoembryonic Antigen↗
PubMed1986

[In vivo antibacterial activity of cefbuperazone. Synergy of cefbuperazone for bactericidal effect with human polymorphonuclear leukocytes].

Studies were done utilizing E. coli No. 59 which are resistant against human and mouse serum, and the following results were obtained. The therapeutic effect of cefbuperazone (CPBZ) against systemic infections of mice was much higher than that of cefmetazole (CMZ), cefotetan (CTT), latamoxef (LMOX) and cefoperazone (CPZ). Synergistic bactericidal effect with human polymorphonuclear leukocytes was more marked for CBPZ than CMZ.

Animals↗
PubMed1986

Separation of an inhibitor of erythropoiesis in "middle molecules" from hemodialysate from patients with chronic renal failure.

A "middle molecule" inhibitor of erythropoiesis in patients with chronic renal failure was separated from a large amount of hemodialysate. Hemodialysate was passed through Amberlite XAD-4 resin, Sephadex G-50 gel, and DEAE-Sephadex A-25, followed by reversed-phase liquid chromatography. The erythroid colony assay (CFU-E) was used to detect the inhibitory effect of the sample solution. Certain fractions from the DEAE-Sephadex A-25 column showed a dose-related inhibition of CFU-E formation as great as that of standard spermine. The inhibitory effect of these fractions decreased to the control value after proteolytic digestion. The inhibitor was eluted from the liquid-chromatographic column by a solvent gradient containing 390 to 425 mL of methanol per liter. These results suggest there is an inhibitor of CFU-E with a relative molecular mass of 1000 to 10 000 and an active site composed of peptide. This technique may prove useful for separation of the inhibitor of erythropoiesis in uremic body fluid.

Animals↗
PubMed1986

[The normal range of cerebral atrophy during aging: statistical analysis of 500 normal subjects].

We previously reported the newly developed quantitative measurement of the cerebral atrophy (pixel count method), and advocated the value CCR (CSF-cranial ratio) as the index of the volumetric measurement of the cerebral atrophy. As the pixel count method is somewhat troublesome, we tried to compare the various linear measurement methods with pixel count method by means of multivariant analysis, and reported a single formula to calculate CCR from the linear measurement methods. Now we studied 500 normal subjects using the pixel count method and examined the normal range of the cerebral atrophy during aging by means of the maximum likelihood method. The normal range was estimated as follows; 0.32 less than y less than 5.78 (t less than 48), 0.068 t--2.944 less than y less than 0.368 t--11.884 (t greater than 48). Using these formula and this newly reported normal range, we can easily predict whether the cerebral atrophy is pathological or not.

Aging↗
PubMed1985

Primary neuroblastoma of the nasal cavity and review of literature.

Primary neuroblastoma of the nasal cavity is very rare, and it is one of the most difficult tumor to differentiate from other small round cell tumors. The present case was proved to be olfactory neuroblastoma by histological, electron microscopical and histochemical findings. This is the first case in which biogenic amines were proven by glyoxylic acid-induced fluorescence in vitro. Discussions were made on the pathological differences with adrenal neuroblastoma.

Adult↗
PubMed1985

Body position with respect to the head or body position in space is coded by lumbar interneurons.

In decerebrate cats, we have studied the response of neurons in the L3-L6 segments of the spinal cord to stimulation of neck and vestibular receptors. Neck receptors were stimulated by head rotation in labyrinthectomized cats or by body rotation with the head fixed in labyrinth-intact cats. Vestibular receptors were stimulated by whole-body tilt in the latter preparation. Most neurons were located outside the motoneuron nuclei and were arbitrarily classified as interneurons. Combinations of roll and pitch stimuli at frequencies of 0.1 or 0.05 Hz were used to determine the horizontal component of the polarization vector, i.e., the best direction of tilt, for each neuron. Two types of stimuli were used; rotation of a fixed angle of tilt around the head or body ("wobble," Ref. 22) or sinusoidal stimuli in several planes. Polarization vectors of the responses to neck stimulation were widely distributed; different neurons responded best to roll, pitch, and angles in between. For every neuron, the amplitude of the response decreased as the cosine of the angle between the direction of maximal sensitivity and the plane of the stimulus. The direction of the vector remained stable as the frequency of stimulation was varied. Neurons with different vectors had similar dynamics that resembled those of cervical interneurons (27). Many neurons responded to both neck and vestibular stimulation, although the vestibular response usually had a much lower gain. Neck and vestibular vectors were approximately opposite in direction. We suggest that neck responses originate in receptors, probably spindles, in perivertebral muscles. Each of these muscles presumably is best stretched by a particular direction of pull. It seems likely that convergence from receptors in selected muscles determines the direction of a spinal neuron's vector. Vestibular responses probably are due mainly to activity in otolith afferents.

Animals↗
PubMed1985

Control of abdominal muscles by brain stem respiratory neurons in the cat.

Control of abdominal musculature by brain stem respiratory neurons was studied in decerebrate unanesthetized cats by determining 1) which brain stem respiratory neurons could be antidromically activated from the lumbar cord, from which the abdominal muscles receive part of their innervation, and 2) if lumbar-projecting respiratory neurons make monosynaptic connections with abdominal motoneurons. A total of 462 respiratory neurons, located between caudal C2 and the retrofacial nucleus (Bötzinger complex), were tested for antidromic activation from the upper lumbar cord. Fifty-eight percent of expiratory (E) neurons (70/121) in the caudal ventral respiratory group (VRG) between the obex and rostral C1 were antidromically activated from contralateral L1. Eight of these neurons were activated at low thresholds from lamina VIII and IX in the L1-2 gray matter. One-third (14/41) of the E neurons that projected to L1 could also be activated from L4-5. Almost all antidromic E neurons had an augmenting firing pattern. Ten scattered inspiratory (I) neurons projected to L1 but could not be activated from L4-5. No neurons that fired during both E and I phases (phase-spanning neurons) were antidromically activated from the lumbar cord. In order to test for possible monosynaptic connections between descending E neurons and abdominal motoneurons, cross-correlations were obtained between 27 VRG E neurons, which were antidromically activated from caudal L2 and contralateral L1 and L2 abdominal nerve activity (47 neuron-nerve combinations). Only two neurons showed a correlation with one of the two nerves tested. Although there is a large projection to the lumbar cord from expiratory neurons in the ventral respiratory group caudal to the obex, cross-correlation analyses suggest that strong monosynaptic connections between these neurons and abdominal motoneurons are scarce.

Abdominal Muscles↗
PubMed1985

Tonic neck reflex of the decerebrate cat: a role for propriospinal neurons.

In decerebrate, acutely labyrinthectomized cats we used neck rotation to study the role of direct upper cervical afferents to the cervical enlargement and of cervical and lumbar propriospinal neurons in the tonic neck reflex. Interruption of the dorsal columns between C4 and C5 had no qualitative effect on the dynamics of the reflex although gain usually increased. Direct upper cervical afferents to the cervical enlargement therefore have no unique role in producing the reflex. Many medially located propriospinal neurons in C4 were modulated by neck rotation. About 40% had axons, mostly crossed, that terminated in the cervical enlargement. The others projected more caudally, some as far as L3-L4 or even the lumbar enlargement. For a population of C4 neurons, including propriospinal neurons, we measured the response vector with combinations of roll and pitch stimuli. These vectors ranged from pitch to roll. Many propriospinal neurons in L3-L4, projecting to the lumbosacral enlargement, were also modulated by neck rotation with a variety of response vectors. Some of these neurons had an ascending projection. As in previous experiments, C4 neurons were modulated by neck rotation after spinal transection rostral to the C1 dorsal root entry zone; a wide variety of response vectors was observed. In contrast, almost no modulated L3-L4 neurons were found in the same experiments. The results suggest a role for propriospinal neurons in the tonic neck reflex. They also demonstrate that responses of lumbar neurons to neck rotation are much more dependent on supraspinal pathways than are those of cervical neurons.

Animals↗
PubMed1985

Effect of a polysaccharide fraction from Grifola frondosa on immune response in mice.

The biological and immunomodulating activities of polysaccharide fraction (GF-1), an antitumor poysaccharide fraction from cultured fruiting bodies of Grifola frondosa, was examined in mice. GF-1 showed no cytocidal effect on culturing tumor cells. However, GF-1 induced resistance against Sarcoma 180 in ICR mice which had completely regressed from the tumor by the effect of GF-1. The administration of GF-1 into mice increased the weights or cell numbers of spleen, and peritoneal cavity. GF-1 enhanced the antigen specific antibody response and carbon clearance activity, whereas GF-1 did not show polyclonal B cell activation and mitogenic activities, and the effect on delayed type hypersensitivity.

Animals↗
PubMed1985

Effect of a B cell mitogen extracted from a fungus Peziza vesiculosa on antibody production in mice.

The effect of Vesiculogen (a hot-water extracted B cell mitogen from Peziza vesiculosa) on antibody production in mouse spleens was studied. The number of plaque-forming cells (PFC) elicited by injection with Vesiculogen and/or 2,4,6-trinitrophenyl substituted sheep red blood cells (TNP-SRBC) were comparatively assayed. In the mice injected with 100 micrograms of Vesiculogen (i.p.), an obvious increase in the numbers of anti-SRBC and anti-TNP SRBC PEC in spleens was observed after 2 d of injection, and the numbers of PFC reached a maximum on day 3. Injections to 1-1000 micrograms of Vesiculogen were effective. This effect was shown when Vesiculogen was administered by i.p. or i.v. injections. In some cases, the numbers of PFC in mice injected with Vesiculogen and antigen exceeded the sum of each number of PFC elicited by polyclonal B cell activation activity of Vesiculogen and by antigenic stimulation of TNP-SRBC. Pretreatment with Vesiculogen within 4 d before immunization markedly reduced the PFC response. These results suggest that the effect of Vesiculogen on antibody response in mice attributes to its activities as a polyclonal B cell activator and adjuvant.

Animals↗