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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 235 records · Page 13Linked to original sources
PubMed1989

Competitive Inhibition of Ferrous Iron Oxidation by Thiobacillus ferrooxidans by Increasing Concentrations of Cells.

The oxidation of ferrous iron (Fe) to ferric iron (Fe) with dioxygen (O(2)) by various strains of Thiobacillus ferrooxidans was studied by measuring the rate of O(2) consumption at various Fe concentrations and cell concentrations. The apparent K(m) values for Fe remained constant at different cell concentrations of laboratory strains ATCC 13661 and ATCC 19859 but increased with increasing cell concentrations of mine isolates SM-4 and SM-5. The latter results are explained by the competitive inhibition of the Fe-binding site of a cell by other cells in the reaction mixture. Possible mechanisms involving cell surface properties are discussed.

Journal Article↗
PubMed1989

Antitumor and immunomodulating activities of a beta-glucan obtained from liquid-cultured Grifola frondosa.

The effects of the beta-1,3-glucan, LELFD, obtained from liquid-cultured mycelium of Grifola frondosa, on the growth of syngeneic tumors and immune responses in mice were examined. In Meth A or IMC solid tumor systems, LELFD administered intraperitoneally (i.p.) or intralesionally (i.l.) exhibited significant antitumor effects. However, the growth of L1210 and P388 leukemias was unaffected by the injection of LELFD. The injection of LELFD i.p. enhanced the activities of natural killer cells and macrophages in mice. LELFD also enhanced the antibody response when it was injected i.p. with sheep red blood cells into mice. Furthermore, it was found that LELFD could activate the alternative complement pathway.

Adjuvants, Immunologic↗
PubMed1989

Effect of cysteine on the inactivation of cystathionine gamma-lyase by D,L-propargylglycine.

In vivo inactivation of cystathionine gamma-lyase by D,L-propargylglycine, a suicide inhibitor, was found to be less profound in rat kidney than in the liver. We investigated the cause of this difference using rat tissues. We fractionated kidney extract to characterize the substance which protected enzyme, and found that cysteine exhibits protecting action. Addition of 0.3 mM L-cysteine to the incubation mixture containing dialyzed kidney supernatant and 0.5 mM D,L-propargylglycine resulted in the protection of cystathionine gamma-lyase from the inactivation by the inhibitor. The content of cysteine in the kidney was six-fold higher than that in the liver. Thus, we have concluded that one of the reasons why the in vivo inactivation of cystathionine gamma-lyase in rat kidney was less than that in the liver is the presence of a higher concentration of cysteine in the kidney. S-Carboxymethylcysteine, a cysteine derivative, exhibited a similar, but weaker, protective effect.

Alkynes↗
PubMed1989

Stimulation of DNA chain initiation by a protein factor (NPF-1) from rat liver of different ages.

DNA Polymerase-alpha/primase complexes have been isolated from human neuroblastoma IMR-32, embryonic chicken brains (ECB) and rat prostate tumor PA-3 cells. In the presence of (NH4)2SO4 the major part (90%) of primase activity is released from the Pol-alpha/primase complex. A novel hydrophobic interaction column was used for purification of the primase from PA-3 cells. A nuclear protein factor (NPF-1) that stimulates DNA pol-alpha/primase activity has been purified from rat liver of various ages (3-6 months). The nuclear protein factor which only stimulates the primase activity is under investigation. The monoclonal antibodies (SJK 132-20 and 237-71) were used to detect DNA pol-alpha polypeptides from 11- to 19-day-old embryonic chicken brains.

Aging↗
PubMed1989

[Arylsulfatase activity of asthmatic children].

Human eosinophil arylsulfatase (AS) is known to inactivate a slow reacting substance of anaphylaxis (SRS-A). Arylsulfatase A (AS-A) and arylsulfatase B (AS-B) activity was assayed by a modification of the method of Inoue using chromatography, and peripheral eosinophil cell counts were obtained to observe the circadian rhythm of 6 healthy controls and 7 children with asthma. There was no significant diurnal variation in AS between the two groups. Eosinophil counts of both groups were lower in the morning and higher at night. Theophylline and beta 2 stimulants did not affect these activities significantly. Forty asthmatic children were selected to evaluate AS activity and eosinophil counts during and after attacks. AS-B activity was significantly higher in children during attacks than at other times, 5.70 +/- 2.00 vs. 3.74 +/- 0.66 4 MUnmol/ml/2hr (p less than 0.05). This result was more evident within 24 hours of the attack (p less than 0.01). Eosinophil counts were significantly lower during attack, and there was a negative correlation between the eosinophil counts and AS-B activity. AS-B activity in mild asthmatic children was greater than in severe cases. A significant rise in AS-B was seen in EIB negative asthmatics (p less than 0.01), but no remarkable change was seen in either AS-A or AS-B in the EIB positive group. The data suggest that higher AS-B activity during asthma attacks could inactivate SRS-A and modulate allergic inflammatory reaction.

Adolescent↗
PubMed1989

Experimental autoimmune uveoretinitis (EAU) in rats: isolation of S-antigen, EAU susceptibility of rat strains, genetic control of EAU induction, and effects of cyclophosphamide and irradiation on EAU.

Highly purified S-antigen was isolated from bovine retinas by high performance liquid chromatography (HPLC), and was used to induce experimental autoimmune uveoretinitis (EAU) in various rat strains. Studies were then made of the genetic control of EAU, the effects of cyclophosphamide or irradiation on EAU, and the correlation between the EAU incidence and the serum levels of antibody to S-antigen. Lewis rats were the most susceptible to EAU followed by Wistar rats. F344 rats and BN rats were resistant to EAU. (Lewis X BN)F1 rats and (LBNF1 X Lewis) rats were susceptible to EAU, while (LBNF1 X BN) rats were resistant. These results indicate that susceptibility to EAU was inherited as an autosomal dominant trait. Treatment of rats with cyclophosphamide or irradiation (200 rad/rat) on the day before immunization markedly suppressed EAU development. On the other hand, the same dose of irradiation 7 days after the immunization did not affect the disease induction, yet the antibody levels to S-antigen were very high in the rats. In addition, BN rats resistant to EAU exhibited very high levels of antibody to S-antigen. Therefore, the antibody to S-antigen seems to play a minor role, if any, in the immunopathogenic mechanisms of EAU.

Animals↗
PubMed1989

Alpha 1-antitrypsin and hepatic fibrosis.

The administration of alpha 1-antitrypsin, both sialo and asialo types, to rats with chronic liver injury accelerated hepatic fibrosis. More fibrosis was seen histologically and the amount of hydroxyproline in the liver increased. Moreover, the growth of HEL cells (human embryonal lung fibroblast) in culture was promoted by alpha 1-antitrypsin though the action of the asialo type was very weak by contrast with the sialo type.

Animals↗
PubMed1989

Experimental autoimmune uveoretinitis (EAU) in rats: abrogation of resistance to the induction and augmentation of the inflammation by pertussis toxin.

The effect of pertussis toxin (PT) on experimental autoimmune uveoretinitis (EAU) induced by immunization with S-antigen was examined in rats. Intravenous administration of PT (2 micrograms/rat) initiated the development of EAU in rats that had been made resistant to the induction of EAU by immunization with S-antigen and complete Freund's adjuvant (CFA). The capacity of PT to promote EAU was also demonstrated by a marked augmentation of the inflammation in EAU eyes of rats susceptible to the induction of EAU. PT was most effective when it was given from the day before to the day after immunization with S-antigen. However the induction of EAU was promoted by the injection of PT even 7 days before and 14 days after immunization. The clinical and histopathological findings of the EAU produced by the additional PT treatment were described and the mechanisms by which PT augmented the induction of EAU were discussed.

Animals↗
PubMed1989

[A radical operation of Chiari's disease using the internal shunt tube of the inferior vena cava].

A case with the Budd-Chiari syndrome due to the right hepatic occlusion who was successfully operated by using the internal shunt tube of the inferior vena cava was reported. The patients was 33 year old male. Midsternal incision and right subcostal oblique incision were made and the internal shunt tube was inserted through the right auricle to the inferior vena cava. The hepatic vein was approached through the longitudinal suprahepatic caval venotomy. Then membranous obstruction in the right hepatic vein ostia was resected. Mesenteric venous pressure dropped immediately from 360mm H2O to 160mm H2O by direct manometry. All the blood bled from the right hepatic vein was transfused through the internal shunt tube to the right atrium. The patient tolerated the procedure and his postoperative course was free from the complication. The resected membrane was congenital anomaly and an operative liver biopsy was demonstrated the evidence of congestive liver with fibrosis.

Adult↗
PubMed1989

[Traumatic transection of the left main bronchus and laryngeal fracture resulting from blunt trauma--a successful case of emergency operation].

A 18-year-old female, who had incomplete transection of the left main bronchus and laryngeal fracture, due to blunt trauma, is reported. Chest X-ray on admission showed subcutaneous emphysema extending to the cervical soft tissues and marked pneumomediastinum. Bronchoscopic examination revealed disruption of the left main bronchus, leaving only the membranous portion. An emergency operation was performed 5 hours after the injury. A week later, bronchoscopic reexamination revealed tracheal stenosis just below the vocal cord, due to fracture of the cricoid and thyroid cartilages, which was enlarged to a certain extent by laryngoscopic intervention under cooperation of the laryngologist. The patient's postoperative course was uneventful, and two months later, was well with tracheostomy.

Adolescent↗
PubMed1988

Phorbol myristate acetate potentiates superoxide release and membrane depolarization without affecting an increase in cytoplasmic free calcium in human granulocytes stimulated by the chemotactic peptide, lectins and the calcium ionophore.

We investigated the inter-relationships of superoxide (O2-) release, membrane depolarization and an increase in cytoplasmic free Ca2+, [Ca2+]i, in human granulocytes stimulated by various agonists. When concanavalin A or the Ca2+ ionophore ionomycin was used as stimulus, an increase in [Ca2+]i clearly preceded the onset of membrane depolarization, which was followed by O2- release. On the other hand, when N-formylmethionylleucylphenylalanine or wheat-germ agglutinin was used as stimulus, no demonstrable lag was seen in any of the responses. O2- release and membrane depolarization stimulated by all these agonists were markedly potentiated in parallel by pretreatment of cells with a low concentration of phorbol myristate acetate (0.25 ng/ml), whereas an increase in [Ca2+]i was not affected or minimally potentiated. The lag time between addition of the stimulus (concanavalin A or ionomycin) and onset of membrane depolarization or O2- release was significantly reduced by pretreatment of cells with phorbol myristate acetate, whereas the lag time between addition of concanavalin A and onset of the increase in [Ca2+]i was not affected. The dose-response curves for triggering of O2- release and membrane depolarization by each of receptor-mediated agonists in phorbol myristate acetate-pretreated or control cells were identical. These findings suggest that; (a) an increase in [Ca2+]i stimulates membrane depolarization indirectly; (b) a low concentration of phorbol myristate acetate potentiates membrane depolarization and O2- release by acting primarily at the post-receptor level, in particular, at the level distal to an increase in [Ca2+]i, but not by augmenting an increase in [Ca2+]i; and (c) the system provoking membrane depolarization and the system activating NADPH oxidase share a common pathway, which may be susceptible to a low concentration of phorbol myristate acetate.

Calcium↗
PubMed1988

Excitatory input to burst neurons from the labyrinth and its mediating pathway in the cat: location and functional characteristics of burster-driving neurons.

1. Spikes of single neurons were recorded extracellularly in the cat prepositus hypoglossi nucleus and the underlying reticular formation and were identified as type II neurons by horizontal rotation. Among these neurons, those activated by contralateral vestibular nerve stimulation with short latencies (1.5-3.0 ms) were selected for further study. 2. A class of these identified neurons was antidromically activated from the contralateral excitatory burst neuron (EBN) area immediately rostral to the abducens nucleus. Systematic tracking for antidromic stimulation revealed a wide distribution of effective spots in and near the EBN area, with varied latencies and thresholds, suggesting terminal branching in that area. The same neurons were also antidromically activated from the contralateral inhibitory burst neuron (IBN) area, the region near the midline, and the nucleus reticularis tegmenti pontis. 3. These neurons exhibited a characteristic firing pattern related to nystagmus: with contralateral rotation the firing rate gradually increased during the slow phase (type II response) and further steeply increased in a burst fashion before and during the contraversive quick phase. Since the time of occurrence of burst activity in these neurons was similar to that of contralateral ENBs and IBNs that received their axonal projection, it is suggested that they send excitatory input to burst neurons, and can thus be called burster-driving neurons (BDNs). 4. Intracellular study revealed that stimulation of the BDN area produced monosynaptic EPSPs in contralateral EBNs. The monosynaptic connection of BDNs with EBNs was confirmed by detecting unitary extracellular synaptic currents of EBNs with the spike-triggered averaging technique. 5. In contrast to BDNs, another class of nystagmus-related type II neurons in the prepositus hypoglossi and medullary reticular formation showed a discharge pattern similar to that of abducens motoneurons on the same side. None of them was antidromically activated from the contralateral pontine reticular formation including the EBN area. Some neurons responded antidromically to stimulation of the ipsilateral dorsomedial pontine reticular formation. 6. In conclusion, the input from the horizontal canal during rotation reaches the contralateral prepositus hypoglossi nucleus and the underlying reticular formation through the vestibular nuclei, and a class of neurons in these structures (BDNs) responds to the canal input in a burst fashion following a tonic type II activity. The axons of BDNs cross the midline and monosynaptically excite EBNs on the side of the canal stimulated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Evaluation of histopathologic parameters in predicting cervical lymph node metastasis of oral and oropharyngeal carcinomas.

A retrospective study of 53 patients with squamous cell carcinomas of the oral cavity and oropharynx was undertaken to evaluate histopathologic parameters in predicting cervical lymph node metastasis. Biopsy and surgical specimens were examined for degree of differentiation, pattern and depth of stromal invasion, lymphatic-vascular invasion, and lymphoplasmacytic response in relation to metastasis. The incidence of lymph node metastasis in tumors showing grade III type diffuse invasion (71.4%) and with stromal invasion of more than 8 mm in depth (83.3%) was significantly higher than that of tumors with well-demarcated boundaries (44.4% to 5.2%) and superficial invasion (35.3% to 8.3%). Lymph node metastasis also increased in the presence of lymphatic-vascular invasion by tumor cells, whereas the degree of differentiation and lymphoplasmacytic response was not related to metastasis. Thus, the pattern and the depth of stromal invasion and the presence of lymphatic-vascular invasion were important indicators in prediction of cervical lymph node metastasis. Prophylactic neck dissection is advocated when grade III type diffuse invasion, invasion exceeding 8 mm in depth, or grade II type invasion accompanied by a 4 mm to 8 mm depth of invasion is observed in a biopsy specimen.

Carcinoma, Squamous Cell↗
PubMed1988

Solubilized glycosyltransferases and biosynthesis in vitro of glycolipids.

The assembly of most of the ceramide-linked glycolipids (GSLs) in eukaryotic cells occurs in Golgi bodies. At least 18 different glycolipid:glycosyltransferases (GSL:GLTs) have been characterized, 10 of which have been solubilized. These GLTs can be classified into 2 distinct groups: 1) GLTs dedicated to either Dol-P-P-sugar(s) or ceramide-linked sugar(s); and 2) GLTs with dual loyalties (i.e., they compete with glycolipid- and glycoprotein-bound oligosaccharides). Studies with solubilized and purified GalNAcT-1 and GalNAcT-2 from embryonic chicken brains prove that GalNAcT-1 (UDP-GalNAc:GM3 beta 1-4GalNAcT) is specific for GSL, whereas GalNAcT-2 (UDP-GalNAc:Gb3 beta 1-3GalNAcT) can transfer to an oligosaccharide containing the alpha-linked terminal galactose. Similarly, GalT-3 (UDP-Gal:GM2 beta 1-3GalT) is more specific for ganglio-oligosaccharide and GalT-4 (UDP-Gal:Lc3 beta 1-4GalT) can transfer galactose to N-acetylglucosamine linked to p-nitrophenol, glycolipid or glycoprotein. Both GalT-3 and GalT-4 have been separated and purified from embryonic chicken brains. Studies with solubilized SAT-4 and SAT-3, from bovine spleen and embryonic chicken brains, respectively, suggest the existence of 2 different gene-expressed alpha 2-3SATs. The newly discovered FucT-3 (GDP-Fuc:NeuGc-iLc6-alpha 1-3FucT) from human colon carcinoma (Colo-205) has also been solubilized and separated from other GSL:GLTs. Using a new activity gel-Western blot combined technique, the molecular mass of this FucT-3 was determined to be 105 kDa.

Animals↗
PubMed1988

Chondrosarcoma of the mandible. Report of case and a survey of 23 cases in the Japanese literature.

A huge chondrosarcoma of the mandible (80 X 95 X 100 mm in size) with extension into the infratemporal fossa is described. The tumour was successfully treated by surgical removal and postoperative irradiation. A survey of the Japanese literature revealed 23 cases of chondrosarcoma with involvement of the mandible. The tumours occurred equally in males and females whose mean age was 38 years. The molar region was the site of predilection. The most common symptom was swelling and it was accompanied by pain in 7 cases and paraesthesia in 5 cases. Radiographically, the lesions were quite variable and with the exception of 3 cases in which information was not available, they consisted of a combination of irregular radiopacity and radiolucency in 9 cases, whereas the predominant feature was radiopacity in 6 cases and radiolucency in 4 cases. There was no radiographical abnormality in 2 cases. Root resorption of adjacent teeth was noted in 3 of 6 cases where information existed. Computed tomography was thought to be quite valuable in determining the nature and extent of the tumour. Although an elevation of serum alkaline phosphatase was observed in our case, results of laboratory tests were mostly of no diagnostic significance. Surgical removal was employed in 22 cases alone or in conjunction with irradiation and/or chemotherapy. Of 14 cases on whom information was available, local recurrence occurred in 6 cases in which radiotherapy was not given and distant metastasis in 2 of 10 cases on whom information was available. Of 20 patients on whom information was available on the postoperative course, 7 patients died 5 months to 6 years after the primary treatment.

Adult↗
PubMed1988

Lesions of spinal and trigeminal dorsal root entry zone for deafferentation pain. Experience of 35 cases.

Spinal and trigeminal dorsal root entry zone destruction (DREZ-tomy) was performed on 35 patients with deafferentation pain of various types. Overall, satisfactory pain relief was obtained in 65.5% of spinal DREZ-tomy cases in the follow-up observation. The result in the brachial plexus avulsion group was the best (82.4% improved), followed by the limb pain group without root avulsion (50.0%), but the truncal or visceral pain group showed the worst result (33.3%). Two patients with postherpetic trigeminal neuralgia were completely relieved of pain in the average follow-up period of 32 months, while in 2 patients with postrhizotomy facial pain, pain recurred 4 months after the operation in 1, and, in the other, pain in the medial part of the face remained unchanged. Complications were seen in about 60% of the patients, which were, however, all mild, except for 2 cases of death due to gastrointestinal disease.

Adult↗