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Biomedical subjects

Y Katoh

Publications and source records attributed to Y Katoh.

At least 217 records · Page 12Linked to original sources
PubMed1988

T-cell-derived factor B151-TRF1/IL-5 activates blastoid cells among unprimed B cells to induce a polyclonal differentiation into immunoglobulin M-secreting cells.

Two distinct murine B-cell differentiation factors, designated B151-TRF1 and B151-TRF2, were described originally as B151K12 T-cell hybridoma-derived lymphokines that induce immunoglobulin (Ig) secretion by antigen-activated B cells and unstimulated B cells, respectively. In the present study, we found that a highly purified B151-TRF1 fraction prepared by reversed-phase high-performance liquid chromatography (RP-HPLC) also has the ability to cause a polyclonal differentiation of unstimulated B cells into IgM-secreting cells in the apparent absence of co-stimulant. The activity of the B151-TRF1 fraction but not the B151-TRF2 fraction on unstimulated B cells was markedly inhibited by addition of a monoclonal antibody (mAb) specific for the B151-TRF1/IL-5 to the culture. To determine whether B151-TRF1/IL-5 and B151-TRF2 act on distinct populations among unstimulated B cells, the responsiveness of neonatal B cells and adult B cells that had been fractionated by Percoll density gradient centrifugation was assessed. B151-TRF1/IL-5 predominantly acted on lower density B cells, which appeared around 3 weeks after birth in the spleen. In contrast, B151-TRF2 could activate both lower and higher density B cells almost equally and B151-TRF2-responsive B cells were already present by 1 week of age. Thus, these results suggest that B151-TRF1/IL-5 and B151-TRF2 act on distinct subpopulations among antigen-unprimed normal B cells to induce IgM-secreting cells.

Animals↗
PubMed1988

[The character of premature baby's blood taurine concentration and urinary taurine excretion].

The concentration of taurine in fetal blood and in mother's milk is very high. In the present study, in order to elucidate the nutritional role of taurine during fetal and neonatal age we investigated the urinary taurine excretion and the blood taurine concentration change in premature babies. 1. The blood taurine concentration of infants on the first postnatal day decreased along with gestation between 7-10 gestational months. On the other hand, there was no difference in the concentrations of blood total amino acids in infants on the first postnatal day in 7-10 gestational months. 2. The blood taurine concentration of infants decreased remarkably during one week after birth. This tendency to decrease was more prominent in premature infants--those at 8 to 10 gestational months. 3. The urinary excretion of taurine and total amino acids of infants remarkably decreased along with gestation between 7-10 gestational months. This tendency to decrease was the most prominent in infants between 7 and 8 gestational months.

Amino Acids↗
PubMed1988

[A case report of advanced ovarian cancer with chronic renal dysfunction treated by CDDP i.p].

Reported in this paper is a case of a 56-year-old female patient who was diagnosed as having an ovarian cancer (stage T 4) with a renal dysfunction (CCr 30.5 ml/min). We instilled CDDP intra-peritoneally (CDDP-ip), taking into consideration the peritoneal clearance (CLp.). The administration of sodium thiosulphate also was combined. The low CLp. of this case (299.2 ml/h) made it possible to instill a high dose in the peritoneal cavity and a low dose in the plasma. This method provided enough of anti-tumor effect and kept the renal function safe. We believe that the CLp. is the most important factor in determining the effect and side effects of CDDp-ip.

Cisplatin↗
PubMed1988

[Radical endoscopic treatment of early gastric cancer-indication for and evaluation of endoscopic resection].

In the endoscopic treatment of early gastric cancer, it is absolutely necessary to adapt a radical approach. The indication for this technique in 545 surgically resected cases of single gastric cancer was studied and technical evaluation was made of endoscopic resection (ER) in 98 of early gastric cancer lesions. Except for 2 special lesions of early gastric cancer, invasion depth m and sm minute invasion [sm(+)] cancer did not show lymph node metastasis [n(+)], but this was recognized in sm(++) cancer showing more than moderate invasion and which was deeper than pm cancers. The applicable lesions were selected excluding the n(+)-risk group with invasion deeper than sm(++) based on histological type, macroscopic type, size and the presence or absence of ulcers(Ul). These were differentiated type II a less than 2 cm in size, differentiated type Ul(-) II c of less than 1 cm and undifferentiated type Ul(-) II c of less than 5 mm in areas excluding the fundic gland mucosa. Our method of ER is endoscopic double snare polypectomy. II a or II c lesion is artificially squeezed into a pedunculated form. The cutting snare is placed over the peduncle, the grasping forceps are replaced with another snare to grasp the tumor firmly. Then cutting snare is applied to include sufficient normal mucosa surrounding the lesion and coagulating current is passed through to slowly resect the ared. The 1st-ER healing ratio, remnant ratio and recurrence ratio of standard ER in 55 II a and 30 II c lesions were 83.5, 12.9 and 3.5% respectively. The recurrent cases were retrospectively found originals in the remnant. Among remnant and recurrences, the 2nd-ER healing ratio was 43% (6/14) and surgically treated cases were 8 (6 inapplicable cases), the final ER healing ratio being 90.6% and satisfactory. Most of the remnant lesions were II a of more than 2 cm, and II c of more than 1 cm for differentiated type and II c for undifferentiated type. As ER could not be applied to these lesions, its indication was confirmed to be technically satisfactory.

Gastroscopy↗
PubMed1987

The GABAergic neurons and axon terminals in the lateralis medialis-suprageniculate nuclear complex of the cat: GABA-immunocytochemical and WGA-HRP studies by light and electron microscopy.

In order to get more detailed information on the neural circuit of the lateralis medialis-suprageniculate nuclear (LM-Sg) complex of the cat, the GABAergic innervation of this complex was studied by GABA immunohistochemical techniques. Small immunoreactive cells were found throughout the LM-Sg complex. On the basis of their ultrastructural features, these GABAergic cells were identified as Golgi type II interneurons. The neuropil of this nucleus displayed a conspicuous granular immunoreactivity. Ultrastructurally, the immunoreactive neural profiles in the neuropil were identified as the presynaptic dendrites of interneurons, myelinated axons, or axon terminals. The GABAergic dendritic profiles, containing pleomorphic synaptic vesicles, were involved in synaptic glomeruli. Additionally, GABAergic axon terminals containing pleomorphic synaptic vesicles formed symmetric axodendritic synaptic contacts mainly in the extraglomerular neuropil. They appeared to correspond to either axon terminals from the thalamic reticular nucleus (TRN) or the axon terminals of interneurons. The projections from the TRN to the LM-Sg complex were studied by using wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). Following injection of WGA-HRP into the LM-Sg complex, a number of retrogradely labeled cells were observed in the TRN. The connections between the TRN and the LM-Sg complex appeared to be topographically organized, the dorsal TRN being connected mainly with the dorsomedial portion of the LM-Sg complex, and the ventral TRN being connected chiefly with the ventrolateral portion of the LM-Sg complex. Following injection of the tracer into the TRN, ultrastructural examination of anterograde labeling in the LM-Sg complex revealed that labeled terminals contain pleomorphic vesicles and make symmetric synaptic contacts mainly with small to medium-sized dendrites. The labeled terminals were not involved in synaptic glomeruli. The present results provide anatomic support for the contention that the projection cells of the LM-Sg complex may be inhibited by both the TRN axons and interneurons, probably through the mediation of GABA.

Animals↗
PubMed1987

Polyclonal B cell activation by a B cell differentiation factor, B151-TRF2. III. B151-TRF2 as a B cell differentiation factor closely associated with autoimmune disease.

We demonstrated previously that B151K12 T cell hybridoma produces two distinct B cell differentiation factors, B151-TRF1 and B151-TRF2, capable of inducing differentiation of antigen-activated and unstimulated B cells into antibody-forming cells, respectively. In the present study we investigated the pathophysiologic relation of these factors with factors obtained from MRL/MP-lpr/lpr(MRL/lpr) mice and (C57BL/6 X DBA/2)F1 (BDF1) mice undergoing chronic graft-vs-host reaction (GVHR), representing a murine model of systemic lupus erythematosus with polyclonal B cell activation associated with the T cell hyperfunction. The functional and biochemical analyses revealed that B151-TRF2-like, but not B151-TRF1-like, activity was found in culture fluid supernatant (CFS) of lymphoid cells from MRL/lpr mice with lymphoproliferative syndrome. On the other hand, both B151-TRF1- and B151-TRF2-like activities were detected in CFS prepared from spleen cells of BDF1 mice undergoing chronic GVHR by the inoculation of parental DBA/2 spleen cells. Interestingly, spleen cells of BDF1 mice transferred with DBA/2 thymocytes preferentially elaborated B151-TRF1-like factor. Because BDF1 mice transferred with DBA/2 spleen cells but not with DBA/2 thymocytes developed a SLE-like syndrome exemplified by the appearance of Coombs' antibody and proteinuria, it seemed likely that production of B151-TRF2-like factor was closely associated with the onset of autoimmune disease. In fact, B151-CFS containing B151-TRF2 but not B151-TRF1 activity could induce a striking autoantibody production both in vivo and in vitro as detected by PFC responses of normal mice to bromelain-treated mouse red blood cells (BrMRBC). Moreover, it was demonstrated that in vitro anti-BrMRBC PFC responses induced by semipurified B151-TRF2 was markedly inhibited by addition of relevant anti-Ia antibody to the culture. Thus, the present study demonstrates that B151-TRF2 represents one of the B cell differentiation factors responsible for polyclonal B cell activation leading to autoantibody production.

Animals↗
PubMed1987

Parathyroid hormone and electrolytes during long-term treatment with allopurinol and thiazide.

We have investigated the composition of plasma and urine in patients with recurrent calcium calculi treated with allopurinol alone, thiazide alone, and both agents together for more than 18 months, and compared the results with those of patients receiving no treatment. In patients treated with allopurinol, both plasma and urinary uric acid were decreased, and plasma parathyroid hormone (PTH) and urinary calcium were increased between 1 and 2 years after treatment. In patients treated with thiazide, plasma calcium was decreased 3 months after treatment but then increased gradually, although the pre-treatment level was not reached. Urinary calcium was decreased 3 months after treatment but returned to pre-treatment levels at 6 and 12 months. Plasma PTH was gradually increased. In patients treated with both allopurinol and thiazide, plasma and urinary uric acid, plasma potassium and urinary calcium were decreased during treatment. Plasma PTH increased gradually during treatment. In patients receiving no treatment, the composition of plasma and urine did not alter during follow-up. The reasons for the changes in urinary calcium and plasma PTH have been discussed.

Adult↗
PubMed1987

[Human placental glutathione transport mechanism].

The placental transport mechanism of glutathione (GSH) was investigated using microvillous membrane vesicles prepared from human term placenta. Using (3H-glycine)-labeled-GSH, it was clarified that GSH in the extravesicular compartment of placental microvillous membranes was rapidly degraded by gamma-GTP (gamma-glutamyltranspeptidase) and resulting amino acid, and 3H-labeled-glycine was actively transported via a sodium cotransport system. AT-125 treated microvillous membrane vesicles almost entirely lost its gamma-GTP activity, and showed intact GSH transport. Using AT-125 treated microvillous membrane vesicles, it was revealed that GSH was transported across the microvillous membrane as an anion via a membrane potential-dependent mechanism. These results indicated that gamma-GTP which existed in microvillous membrane played a role in GSH metabolism and that intracellular GSH was translocated out of the syncythiotrophoblast cell into the maternal blood space via a specific carrier in microvillous membrane because the GSH concentration was higher in intracellular than extracellular and extracellular membrane potential was positively charged.

Biological Transport, Active↗
PubMed1987

[The study on human placental DHA-S transport mechanism (using placental microvillous membrane vesicles)].

To investigate the placental DHA-S (dehydroepiandrosterone sulfate) transport mechanism, the uptake of DHA-S into microvillous membrane vesicles prepared from human term placenta was studied using the rapid filtration technique. 1. The uptake of DHA-S into microvillous membrane vesicles was not dependent on both Na+ electrochemical gradient and membrane potential difference. 2. The uptake of DHA-S into microvillous membrane vesicles was dependent on temperature. The initial uptake rate of DHA-S at 37 degrees C was three times as great as at 4 degrees C. 3. The initial rate of DHA-S transport exhibited saturation kinetics with respect to the DHA-S concentration; an apparent Km of 0.067 mM and Vmax of 1.01 nmol/mg protein/20 sec were calculated. 4. The uptake of DHA-S into microvillous membrane vesicles was inhibited by DHA, but not by estriol. These results indicated that placental DHA-S transport was carrier mediated and a passive one.

Biological Transport↗
PubMed1987

[Effects of parathyroid hormone on the cardiovascular system].

It has been well accepted that the bone and kidney are the principal organs of parathyroid hormone (PTH) actions, but there has been little work on the cardiovascular system. We evaluated the effect of PTH on the cardiovascular system of rats. In thiobutabarbital anesthetized rats, synthetic bovine parathyroid hormone, containing the amino acid (b-PTH 1-34) in dose of 0.1-10 micrograms/kg iv, caused dose related decrease in mean arterial blood pressure (MAP). On the other hand, there were significantly increase in heart rate (HR) and left ventricular contractile force. With the doses of 10 micrograms/kg, PTH decreased the MAP from 104.3 to 55.5 mmHg, left ventricular pressure (LVP) 122.1 to 96.4 mmHg, left ventricular end diastolic pressure (LVEDP) from 6.70 to 6.37 mmHg and LV dp/dt max 5,684 to 4,736 mmHg/sec. The HR, LV dp/dt/p and Vmax increase from 399.7 to 410.0 bpm, 95.5 to 108.4/sec, 98.2 to 107.4/sec, respectively. The propranolol, phentolamine, atropine and promethazine did not affect these actions of PTH. On the basis of these findings, we conclude that PTH has the directory vasodepressive action and the effect of augmentation of the left ventricular contractile force.

Animals↗
PubMed1987

Effects of castration before and after treatment with N-bis (2-hydroxypropyl)-nitrosamine (DHPN) on the development of thyroid tumors in rats treated with DHPN followed by phenobarbital.

The effect of castration on the development of thyroid tumors was studied histologically and biochemically in Wistar rats given a single ip injection of 210 mg of N-bis (2-hydroxypropyl)-nitrosamine (DHPN) followed by phenobarbital (Pb). Castration was performed one week after, or one week before the injection of DHPN. The injection of DHPN was given at the end of the first week, and the rats were fed 500 ppm Pb in the basal diet for 38 weeks from week 3 to week 40. The incidence of thyroid adenomas and cancers was 20% (4/20) and 10% (2/20) in rats treated with DHPN alone. It was 75% (15/20) and 40% (8/20) in rats treated with DHPN and Pb; 30% (6/20) and 15% (3/20) in rats treated with DHPN and Pb, and castrated after DHPN; 20% (4/20) and 0% in rats treated with DHPN and Pb, and castrated before DHPN and Pb; and 0% and 0% in rats castrated either before or after receiving DHPN. Castration thus inhibited the development of thyroid tumor in rats treated with DHPN. The inhibition of tumor development in rats treated with DHPN and Pb, and castrated before receiving DHPN, was greater than in the rats castrated after receiving DHPN. Castration inhibited the secretion of TSH in rats treated with DHPN and Pb.

Animals↗
PubMed1987

[The role of glutathione on placental amino acid transport (using microvillous membrane vesicles)].

To elucidate the role of glutathione (GSH) on placental amino acid transport, we investigated L-lysine transport using microvillous membrane vesicles prepared from full term human placenta. 1. The transport of L-lysine into microvillous membrane vesicles was not affected by glutathione. 2. The transport of L-lysine into microvillous membrane vesicles was inhibited by inorganic mercury (Hg2+), and 0.1mM Hg2+ inhibited 34% of this transport and 1mM Hg2+ inhibited 50%. 3. The transport of L-lysine inhibited by Hg2+ was almost completely restored when glutathione was added simultaneously. These results indicated that glutathione defended the inhibitory action of inorganic mercury on L-lysine transport across microvillous membrane.

Amino Acids↗