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Biomedical subjects

S Katoh

Publications and source records attributed to S Katoh.

At least 217 records · Page 12Linked to original sources
PubMed1992

Application of 67Ga for the estimation of reticulocyte production.

In order to estimate the production of reticulocytes, which have a larger number of transferrin receptors than erythrocytes, we used 67Ga which is exclusively bound to transferrin in the blood. The pattern of uptake of 67Ga by reticulocytes was quite similar to the time course of transglutaminase activity which might be involved in receptor-mediated endocytosis. The preinjection of Fe3+ decreased the uptake of 67Ga by reticulocytes. These results suggested that 67Ga in a transferrin-bound form was taken up by reticulocytes via receptor-mediated endocytosis. It was showed that the application of 67Ga is very easy and useful for the estimation of reticulocyte production.

Animals↗
PubMed1992

Deferoxamine, an iron chelator, reduces myocardial injury and free radical generation in isolated neonatal rabbit hearts subjected to global ischaemia-reperfusion.

The protective action of deferoxamine, an iron chelator, against functional and metabolic deteriorations of ventricular muscle, induced by ischaemia-reperfusion, was investigated in Langendorff-perfused hearts of neonatal rabbits in comparison with superoxide dismutase (SOD) plus catalase. The perfused hearts were subjected to normothermic (37 degrees C) global ischaemia for 45 min following cardiac arrest with St Thomas cardioplegic solution and then reperfused with oxygenated Krebs-Henseleit solution. In control hearts, the recovery of the left ventricular developed pressure (LVDP) after 30 min reperfusion was 50.7 +/- 3.1% (mean +/- SE, n = 5) of the pre-ischaemic value. The LVDP recovery was significantly improved in the hearts treated with deferoxamine at 10-100 microM (89.4 +/- 1.4% at 30 microM, P < 0.01 vs. control). The improvement in LVDP was less prominent when treated with 30 x 10(4) U/l SOD plus 30 x 10(4) U/l catalase (67.9 +/- 2.0%, P < 0.01 vs. deferoxamine at 30 microM). CPK leakage into the coronary effluent during the initial 5 min of reperfusion was reduced to around half of the control value with 30 microM deferoxamine (P < 0.05 vs. control), while unaffected by the addition of SOD plus catalase. Free radicals in the coronary effluent were measured with electron spin resonance spectroscopy in separate experiments by using a spin-trapping agent, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). A burst of DMPO-OH signal was detected during the initial minutes of reperfusion. The intensity of DMPO-OH signal was significantly reduced by 30 microM deferoxamine to about one-third of control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Long duration of erythrocyte hypoplasia after bone marrow transplantation.

Bone marrow transplantation was performed on a 15 year old girl with chronic myelogenous leukemia. The bone marrow was obtained from her younger sister, who was human leukocyte antigen haplo-identical but major ABO incompatible. As a result, the condition of pure red cell aplasia (PRCA) persisted over a long period of time. In order to overcome major ABO incompatibility, erythrocytes were eliminated from the bone marrow graft before transplantation, and methotrexate and cyclosporine (CsA) were used to prevent graft-versus-host disease (GVHD). Administration of erythropoietin proved ineffective. B19 parvovirus infection could not be detected during that time. Agglutinin titers decreased to less than fourfold in parallel with the recovery of erythrocytes. Reports on similar PRCA have been limited to cases of transplantation with ABO incompatibility and cases where CsA was administered to prevent GVHD. This suggests that ABO incompatibility and CsA might be related to the development of PRCA.

ABO Blood-Group System↗
PubMed1992

Successful collection of peripheral blood stem cells from an infant with acute lymphoblastic leukemia using the Haemonetics V50.

Peripheral blood stem cells (PBSC) were collected using the Haemonetics V50 from an 8 month old infant weighing 7.8 kg suffering from acute lymphoblastic leukemia in the first complete remission. Leukapheresis was performed according to an exchange transfusion procedure by the two arm method using only a single lumen Broviac catheter. No problem occurred in the patient during this procedure except for a reduction (by half) of the initial platelet count. This method enables one to collect PBSC very safely, even from infants, in a manner that is painless for patients.

Blood Transfusion, Autologous↗
PubMed1992

Protective action of iron-chelating agents (catechol, mimosine, deferoxamine, and kojic acid) against ischemia-reperfusion injury of isolated neonatal rabbit hearts.

Iron is suggested to play an important role in free radical generation during ischemia reperfusion. In the present study, the protective action of 4 iron-chelating agents, with different iron affinities, against reperfusion injury was examined in Langendorff-perfused hearts of neonatal rabbits. The chelators and their iron-binding constants (log Km) were as follows: catechol (43), mimosine (36), deferoxamine (31) and kojic acid (27). Following cardiac arrest, the hearts were subjected to global ischemia for 45 min at 37 degrees C, and then reperfused with modified Krebs-Henseleit solution for 30 min. In control, the left ventricular developed pressures (LVDP) after 30 min reperfusion recovered to 50.5 %/- 3.0% (mean +/- SEM; n = 5) of the preischemic level. In the hearts treated with catechol (30 microM), mimosine (30 microM) or deferoxamine (30 microM), the LVDP recovery was significantly improved up to 84.9 +/- 1.3, 88.2 +/- 2.9 or 87.4 +/- 1.5%, respectively (p < 0.01 vs. control). Creatine phosphokinase (CPK) leakage during the initial 5 min of reperfusion was significantly decreased to about half of control in the hearts treated with catechol, mimosine, or deferoxamine. However, the treatment with kojic acid (30 microM) showed no improvement in the LVDP recovery and CPK leakage. Free radical generation was measured with an electron spin resonance using a spin-trapping agent, 5,5-dimethyl-pyrroline-N-oxide (DMPO). The treatment with catechol, mimosine, or deferoxamine reduced the maximum intensity of DMPO-OH signal to about one third of control. However, the maximum intensity in the hearts treated with kojic acid showed a similar level to control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Concomitant increase in putrescine incorporation with transferrin uptake into rat reticulocytes.

Concomitant increase in putrescine incorporation with transferrin uptake into rat reticulocytes was found. [14C]Putrescine incorporation occurred in the presence of transferrin at 37 degrees C. The subcellular distribution of incorporated [14C]putrescine showed that the incorporation in the plasma membrane time dependently increased. Both 125I-labeled transferrin uptake and [14C]putrescine incorporation decreased when ethylene glycol bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid was added, while it increased with the addition of A23187.

Animals↗
PubMed1992

Malignant hyperthermia caused by intravenous lidocaine for ventricular arrhythmia.

We encountered a case of malignant hyperthermia caused by intravenous lidocaine which had been administered as treatment for a ventricular arrhythmia. The patient, a 72-year-old male, was admitted with chronic renal failure and aortic valvular stenosis. His chronic renal failure progressed, and congestive heart failure developed, and ventricular arrhythmias occurred frequently. For the treatment of these arrhythmias, lidocaine was injected and continuous infusion was started. Despite initial improvement in symptoms and laboratory data following hemofiltration, refractory ventricular tachycardia occurred. The patient was treated with large doses of lidocaine. His body temperature rose to a maximum of 41.7 degrees C, and generalized muscular twitching was observed before he lost consciousness. Serum and urinary myoglobin levels became elevated. This abnormally high fever was relieved only by dantrolene sodium. After we made a diagnosis of malignant hyperthermia and stopped the lidocaine infusion, the high fever resolved quickly. It is important to note that malignant hyperthermia can be caused by lidocaine and amide-linked local anesthetics.

Aged↗
PubMed1992

Rheumatoid nodules of the lung in a patient with palindromic rheumatism.

We report a case of rheumatoid nodules of the lung seen in a patient with palindromic rheumatism. A 54-year-old man with palindromic rheumatism was admitted for evaluation of three nodules in the right upper lobe on chest roentgenogram. Wedge resection was performed for the purpose of confirmative diagnosis and treatment. Histology of these lung lesions revealed palisaded histiocytic cells surrounding a layer of central necrosis, which were considered to be characteristic findings of rheumatoid nodule. Such a case is extremely rare. To our knowledge, only one other case has been reported before in the literature.

Arthritis, Rheumatoid↗
PubMed1992

Role of enzymes in tetrahydrobiopterin biosynthesis: computer analysis of the sequential reaction of the last step.

Computer simulation analysis of the experimental data showed that Cl'-keto PH4 and C2'-keto PH4 were sequential intermediates of the reduction of PPH4 to BH4 by SPR and that the reaction in the last step of the BH4 biosynthesis proceeds as follows: PPH4-->Cl'-keto PH4-->C2'-keto PH4-->BH4 Cl'-keto PH4 is not detectable in the reduction of PPH4 by the purified SPR at neutral pH since isomerization (-->) [8] may occur far more rapidly than the first reduction (-->).

Alcohol Oxidoreductases↗
PubMed1992

[A successfully treated case of acute renal failure due to acute immune hemolytic anemia and nontraumatic rhabdomyolysis induced by streptomycin reinjection].

A case of acute immune hemolytic anemia associated with non-traumatic rhabdomyolysis (NTR) induced by streptomycin (SM) reinjection, which developed acute renal failure, has been reported. A 70-year-old female was admitted to our hospital because of sudden macroscopic hematuria after reinjection of 1g. SM. Laboratory findings on admission were as follows; hemoglobin and myoglobin were positive in urine. RBC 129 x 10(4)/microliters, Hb 4.9g/dl, Ht 11.1%, reticulocytes 52/1000, serum indirect billirubin 3.8g/dl, LDH 9, 230 WU, BUN 149mg/dl, Cr 7.9mg/dl, myoglobin 1, 400ng/ml and haptoglobin 10.6mg/dl. The drug lymphocyte stimulating test of SM was positive (215%). A direct antiglobulin test was also positive. An indirect antiglobulin test was negative, but became positive after incubation with SM. These observations made the diagnosis of SM-induced hemolytic anemia associated with NTR. On the second hospital day she developed anuria, and was put on hemodialysis treatment. Two months after the acute hemolytic episode and acute renal failure she recovered and is presently in good health without recurrence.

Acute Disease↗
PubMed1992

The relationship of putrescine incorporation to transferrin uptake by reticulocytes.

We previously reported that putrescine incorporation occurred during transferrin uptake by rat reticulocytes (1). Both the putrescine incorporation and transferrin uptake were enhanced by the presence of Ca2+ and A23187. Furthermore, putrescine dose-dependently increased the transferrin uptake. Additionally, transglutaminase inhibitors partially blocked not only the putrescine incorporation but also the transferrin uptake.

Animals↗
PubMed1992

[A case of chronic interstitial pneumonia with benign monoclonal gammopathy (IgM-k) and thrombocytopenia].

A 53-year-old woman was admitted on 13th October 1988 with symptoms of dry cough and shortness of breath persisting for 1 year. On physical examination, fine crackles were audible over her back. Chest X-ray showed bilateral reticulonodular shadows and collapse of the bilateral lower lobes. Chest CT showed patchy areas of increased density distributed predominantly in the subpleural zone. Laboratory data on admission showed thrombocytopenia, hypergammopathy (IgG, 2044 mg/dl; IgA, 286 mg/dl; IgM, 1645 mg/dl), and positive ANF. Further examinations demonstrated that anti-platelet and anti-centromere antibodies were positive in the serum, and the titer of PA-IgG was high (56 ng/10(7) platelets). Histopathological examination of the open lung biopsy demonstrated honeycombing and thickening of the alveolar walls, with slight infiltration of chronic inflammatory cells. These histopathological findings were comparable with usual interstitial pneumonia. We report a very rare case of chronic interstitial pneumonia complicated by benign monoclonal gammopathy and thrombocytopenia. Although it remains unclear, these abnormalities may have been caused by immunological mechanisms.

Autoantibodies↗
PubMed1992

[Acute aortic dissection in a patient with Marfan's syndrome and severe pectus excavatum--emergency surgical repairs of ascending aortic dissection and aortic regurgitation complicated by pectus excavatum in Marfan's syndrome].

A case of acute aortic dissection Stanford Type A occurring in a patient with Marfan's syndrome, complicated with aortic regurgitation and severe pectus excavatum, is reported with successful surgical correction. The patient was a 33-year-old woman, who suffered from severe back pain riding to work. An emergency operation consisting of Cabrol's procedure for aortic dissection Stanford Type A and sternal turnover for pectus excavatum was performed simultaneously. Because of the postoperative mediastinal bleeding the implanted sterno-costal complex was removed on the second POD and the prosthetic sternum was reimplanted on the tenth POD. The two-stage operation seems preferable in such an emergency case to avoid postoperative bleeding and infection.

Acute Disease↗
PubMed1992

[IL-5-and its receptor--the role of IL-5 in the development of hematopoietic cells in the long-term bone marrow cultures].

IL-5 is a T-cell-derived glycoprotein that acts on B cells and eosinophils to induce their growth and differentiation. We clarified using in vitro long-term bone marrow culture that IL-5 supports the growth and survival of Ly-1+ common progenitor cells which can differentiate into Ly-1+ B cells and Ly-1+ macrophages. The functional IL-5 receptor (IL-5R) consists of alpha and beta heterodimers. The 60 kDa alpha chain binds to IL-5 with low affinity, while the 130 kDa beta chain does not bind with IL-5 by itself, but converts low affinity IL-5R to high affinity IL-5R together with the alpha chain. The beta chain is shared with GM-CSFR and IL-3R.

Animals↗
PubMed1991

Chloramphenicol is an inhibitor of photosynthesis.

Chloramphenicol inhibited significantly but incompletely photosynthesis in leaf segments of rice. Fluorescence and polarographic experiments indicated that chloramphenicol competes with the CO2 reducing cycle for electrons from photosystem I because it serves as an electron acceptor of photosystem I and its reduction intermediate transfers its electron to molecular oxygen.

Chloramphenicol↗