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Biomedical subjects

S Kojima

Publications and source records attributed to S Kojima.

At least 685 records · Page 38Linked to original sources

Comparison of the effectiveness of dithiocarbamates on the excretion and distribution of cadmium in mice.

Sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and sodium N-p-methoxybenzyl-D-glucamine dithiocarbamate (MeOBGD) were evaluated for their efficacy in the distribution and excretion of cadmium in mice exposed to cadmium. Mice were injected i.p. with 109CdCl2 (1 mg Cd/kg and 74 kBq of 109Cd/mouse) and 30 min or 24 h later, they were injected i.p. with chelating agents (5% of an LD50). The results of this study indicated that the injection of HBGD to mice pretreated with cadmium can remove cadmium from the body without redistribution of cadmium to the brain, testes, and heart more effectively than that of BGD or MeOBGD.

Animals↗

Gnathostomiasis in Thailand: a survey on intermediate hosts of Gnathostoma spp. with special reference to a new type of larvae found in Fluta alba.

To clarify current status of gnathostomiasis in Thailand, a survey on intermediate hosts has been carried out at various localities since 1987. It was found that Fluta alba (Fresh water eel) as well as Channa striata (snake-headed fish) might be important in playing a role of transmitting the infection either among humans or reservoir animals. During the three years from 1987 to 1989, larvae of Gnathostoma spinigerum were found in 80-100% of F. alba obtained from markets in Nakhon Nayok, with a maximum recovery of 2,582 larvae per eel. Among larvae found in these eels, five were peculiar in possessing four rows of hooklets with complicated branches at the base. Epithelial cells of the intestine of these larvae contained 1-2 nuclei. These observations indicate that the larvae are different from those of reported species of Gnathostoma from Thailand including G. spinigerum, suggesting a possibility of the advanced third-stage larvae of G. malaysiae.

Animals↗

Novel anticoagulant peptides from the functional site of human placental anticoagulant protein.

Histidine-containing peptides SHLRKV and DHTLIR, corresponding to placental anticoagulant protein-I (PAP-I) residues 204-209 and 266-271, respectively, are included in the functional site of PAP-I and exhibit anticoagulant activity, but the peptides in which alanine is substituted for histidine do not. However, the peptide KHALKG, corresponding to the region from Lys-97 to Gly-102, did not exhibit an anticoagulant activity, showing that it is not included in the functional site. These findings thus suggest that His-205 and His-267 are involved in the Ca(2+)- or the phospholipid-binding site of PAP-I but that His-98 is not.

Amino Acid Sequence↗

Aspirin injection test to predict angioplasty outcome in unilateral renovascular hypertension: preliminary report.

We examined the usefulness of aspirin DL-lysine for prediction of the outcome of renal artery angioplasty in renovascular hypertension. The study was carried out in eight hypertensive patients with unilateral renal artery stenosis: six were free from azotemia and two had slight azotemia. Before and 30 min after an intravenous injection of aspirin DL-lysine (18 mg/kg), renal venous and abdominal aortic plasma was sampled and assayed for prostaglandin E2 and plasma renin activity. Blood pressure and heart rate were serially measured at this time. Renal angioplasty was later performed and was technically successful in all patients. In the six patients without azotemia, aspirin inhibited renal prostaglandin E2 synthesis and suppressed renin release from the ischemic kidney, resulting in lowered blood pressure. Renal angioplasty caused plasma renin activity to become normal and lowered high blood pressure. The reduction in blood pressure by angioplasty was correlated with the responses of blood pressure and renin release to aspirin. However, in the two patients with azotemia, aspirin neither suppressed renin release nor lowered blood pressure. Their hypertension was not reduced by the angioplasty. These results indicate that an aspirin injection test could be useful for prediction of the outcome of angioplasty in unilateral renovascular hypertension.

Adult↗

[Electrophysiological studies of a case of startle disease].

A 53-year-old female with startle disease (major form) was reported. An abnormal startle response was the most prominent clinical feature. Physical examination revealed left lateral gaze palsy and left extensor plantar response. The caloric test evoked no responses bilaterally. Blood examinations including lysozomal enzymes and radiological examinations including MRI of the brain were all normal. A pathological startle reflex was elicited by the tap on the upper lip, causing the marked extension of the head with the elbow, hip, and knee joints slightly flexing. The earliest reflex activity in a surface-EMG study was recorded in the masseter muscle and the reflex then spread down the brain stem and the spinal cord. The duration of the discharge varied from 16 to 30 ms. The onset latencies of these responses from the tap were 11.2 ms, 12.7 ms, 14.5 ms, 25.7 ms, 38.5 ms, and 47.5 ms in the masseter, sternocleidomastoid, posterior-neck, biceps brachii, quadriceps femoris, and tibialis anterior muscle, respectively. An averaged electroencephalogram triggered by the taps showed no abnormal EEG activity preceding the pathological startle response, although a negative peak, which was thought as a normal early component of the trigeminal somatosensory evoked potentials, was followed by the reflex. High amplitude SEPs and long loop reflexes were observed following stimulation of the posterior tibial nerve but not of the median nerve. Blink reflexes and auditory evoked potentials were normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiology↗

[Bone marrow transplantation for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia].

We reported the results of 6 allogenic bone marrow transplantation (BMT) and 3 autologous BMT for patients with Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL) by Nagoya BMT group. Two of six patients who received allogenic BMT have continued complete remission (CR) on +639 days and +1,597 days. Four of six patients relapsed on +134, +203, +216, and +267 days. Two patients with a disease-free survival for a long time had both acute and chronic GVHD. It is suggested that graft-versus-leukemia (GVL) effect might prevent the relapse. On the contrary, one patient who received with monoclonal antibodies plus complement-treated autologous bone marrow is free of leukemia on +439 days. Our results suggest the follows. 1) We do chromosomal analysis at initial diagnosis in all cases to do BMT in first CR. 2) We intensify the conditioning regimen for BMT. 3) We study on application of GVL effect to prevent the relapse. 4) We establish the best purging method to eradicate residual leukemic cells for autologous BMT. 5) We do allogenic BMT using HLA-matched unrelated donor for patients without related donor.

Adolescent↗

[The usefulness of diving reflex--the effect on PSVT].

We attempted to use the diving reflex to treat PSVT in five patients, in whom carotid-sinus massage had failed to terminate, PSVT. In three cases PSVT converted to normal sinus rhythm. The patient was seated comfortably, and a pan of ice and water (4 degrees C) was placed on the table in front of the patient. He then took a deep breath and, without expiration, submerged his face in the cold ice and water for about 30 seconds. In case 1, a 68-year-old male, PSVT stopped after facial immersion of 11 seconds. Subsequently, sinus arrest with junctional or ventricular contractions continued for 7 seconds followed by conversion to the sinus rhythm. The duration of facial immersion was 18 seconds. In case 2, a 51-year-old male, PSVT converted to the sinus rhythm in the same way. The duration of facial immersion was 23 seconds. Case 3 was a 27-year-old female with WPW syndrome. PSVT converted to the sinus rhythm after a 6.6 seconds facial immersion. Case 4 and 5 were respectively 72 and 73-year-old males, whose attacks did not respond to the diving reflex for the reason that they could not maintain breath-holding for a sufficient time to activate the reflex adequately. We postulated that apnea might effect the termination of PSVT in case 1 and 2 because relatively long duration of about 20 seconds was necessary to convert PSVT to the sinus rhythm. On the other hand, in case 3, cold water stimulation on the face might play an important role because PSVT converted to the sinus rhythm immediately.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Delay in red blood cell recovery after major ABO incompatible bone marrow transplantation].

In 6 of 27 patients in whom major ABO incompatible marrow was transplanted, the recovery of red blood cells (reticulocyte count greater than or equal to 1%) required more than 50 days after the transplantation. In 3 of them, more than 100 days were required. High titers of pre-transplant anti-A or anti-B agglutinin correlated with the delay in red blood cell recovery (IgM: p less than 0.01, IgG: p less than 0.05). In all of the patients whose pre-transplant IgM titers were 4 or less, and whose IgG titers were 32 or less, the red blood cells recovered within 50 days. Administration of cyclosporine did not correlate with the delay in red blood cell recovery. All the patients finally developed red cell production within 8 months without any treatment.

ABO Blood-Group System↗

Down's syndrome and acute leukemia in children: an analysis of phenotype by use of monoclonal antibodies and electron microscopic platelet peroxidase reaction.

The clinical, hematologic, and immunophenotypic features in 20 patients with Down's syndrome (DS) and acute leukemia were analyzed. Of the 20 patients, all 14 patients who were 3 years old and less were diagnosed as having acute megakaryoblastic leukemia (AMKL) by use of platelet-specific monoclonal antibodies and platelet peroxidase (PPO) reaction in electron microscopy. They were characterized by the presence of bone marrow fibrosis, having a history of myelodysplastic syndrome (MDS) and a poor response to chemotherapy. Only one patient has remained in continuous complete remission for more than 1 year. Acute leukemia in six patients who were older than 4 years was classified as common acute lymphoblastic leukemia antigen (CALLA)-positive acute lymphoblastic leukemia (ALL). In one of six patients classified as ALL, the leukemic blasts simultaneously expressed myeloid-associated surface antigens. All six patients achieved a complete remission and have remained in continuous complete remission and have remained in continuous complete remission from 10 to 52 months from the initial diagnosis. Although it has been suggested that the distribution of types of acute leukemia in patients with DS is similar to that in normal children, the present study shows that the distribution of acute leukemia types is quite different from that in patients without Down's syndrome.

Antibodies, Monoclonal↗

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets III.

In cooperative aggregation of bovine platelets induced by simultaneous addition of PAF and collagen at subthreshold concentrations the following observations were made. (i) Formation of phosphatidic acid and arachidonic acid metabolites, which characterize PAF and collagen alone-induced aggregation, respectively, was observed very obviously. (ii) A thromboxane antagonist did not completely block the cooperative aggregation. The extent of residual aggregation activity was dependent on concentration of collagen used in the simultaneous administration with PAF. These results suggest that both signal transduction pathways activated by PAF and collagen alone at high concentrations are attained by simultaneous addition of both agonists at subthreshold concentrations through unknown mechanisms.

Animals↗

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets, II.

When subthreshold amounts of platelet-activating factor (PAF) and collagen were added simultaneously, strong aggregation of platelets was induced. However, each agonist alone at these concentrations could not induce aggregation at all (S. Kojima et al, (1987) Biochem. Biophys. Res. Commun. 145, 915-920). This cooperativity was observed not only in aggregation but also in changes of intracellular Ca2+ concentration, 47 kDa protein phosphorylation, and formation of thromboxane. These findings suggest that various steps of signal transduction pathways are enhanced during their cooperativity.

Animals↗

Comparison of effectiveness of 3 dithiocarbamates on excretion and distribution of cadmium in rats and mice.

Sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-methylbenzyl-D-glucamine dithiocarbamate (MBGD), and sodium N-p-isopropylbenzyl-D-glucamine dithiocarbamate (PBGD), which were recently synthesized, were evaluated for their efficacy in the distribution and excretion of cadmium in rats and mice exposed to cadmium. Rats and mice were injected i.p. with 109CdCl2 (1 mg Cd/kg and 2 microCi 109Cd/one animal) and 3 days later, they were treated with the dithiocarbamates (400 mumol/kg) every other day for 2 weeks. These dithiocarbamates were effective in removing cadmium from the body without increasing the cadmium content in the kidney. After treatment with BGD, MBGD, and PBGD, cadmium was excreted mainly in the feces and the effect of MBGD and PBGD on the fecal excretion of cadmium was much larger than that of BGD. The treatment with these dithiocarbamates did not cause the redistribution of cadmium to brain, testes, and heart in rats and mice. The treatment of mice with PBGD decreased the concentrations of essential metals in liver, kidney, and brain. The extent of acute toxicity of the dithiocarbamates in mice was in the order PBGD greater than MBGD greater than BGD.

Animals↗

Rapid background reduction of circulating sodium iodide I 125-labelled Pisum sativum agglutinin used as a tumor-imaging radiopharmaceutical by the chemically galactosylated antibody.

Influence on the clearance of background radioactivity from the blood was studied by using a chemically galactosylated antibody to the radiopharmaceutical. Sodium iodide I 125-labelled Pisum sativum agglutinin (125I-PSA) was used as the model tumor-imaging radiopharmaceutical in this series of experiments. Rabbit (anti-PSA) immunoglobulin G (IgG) was chemically galactosylated with varying amounts of cyanomethylgalactose. Galactose concentration ranged from 11 to 17 mol/mol protein. Antibody activity was not affected by chemical galactosylation under the experimental conditions used. Blood clearance of the galactosylated anti-PSA (GAP) in normal mice was enhanced to varying degrees, depending on the degree of galactosylation; similarly, liver uptake was increased with the degree of galactosylation. Following injection of 125I-PSA in normal mice, the lectin was rapidly removed from the blood by subsequent injection of GAP. Increased hepatic uptake of the complex (lectin-galactosylated antibody) via protein-carbohydrate recognition caused the pronounced decrease in the 125I-PSA blood level. The effective time for 125I-PSA removal was as short as 15 min. The potency was dependent on the degree of galactosylation of the antibody. In sarcoma 180 (S-180) tumor-bearing mice, the capacity for blood clearance of 125I-PSA was also positively correlated to the degree of galactosylation. Moreover, the variation in the delivered dose ratio of antibody to lectin proved to lead to a further increase in background clearance. As a result, especially the tumor:blood ratio was significantly improved by a single administration of chemically galactosylated antibody, as compared with the value measured in the presence of unmodified antibody. These initial studies suggest that administration of GAP may improve nuclear imaging with radiopharmaceuticals.

Animals↗

Radioimmunoimaging of tumors with radioactive antibody against a glycoprotein (GP68) found in developing mouse brain.

The in vivo localization of a polyclonal antibody (pAb) against a glycoprotein with a molecular mass of 68 kDa (GP68), which was found in developing mouse brain, was studied in murine tumor models to evaluate potential applications of this antibody for in vivo radioimmunodetection and/or therapy of cancer. The tissue distribution of 125I-labeled GP68 pAb 3 days after i.v. injection into mice bearing four different kinds of solid tumor revealed a high uptake ratio by adenocarcinoma 755 and Lewis 3LL lung cancer. In contrast, the uptake ratio was low in mice bearing Ehrlich solid tumor and sarcoma-180 (S-180). These uptake ratios accorded well with the in vitro binding activity of this antibody with the tumor cells. In an immunoscintigraphic study, adenocarcinoma 755 was successfully visualized with 67Ga-labeled GP68 pAb. The results of these biodistribution and in vivo radioimmunoscintigraphic studies suggest that GP68 antibody may be applicable to the diagnosis and/or therapy of cancer.

Adenocarcinoma↗