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Biomedical subjects

E Tsuda

Publications and source records attributed to E Tsuda.

At least 73 records · Page 4Linked to original sources
PubMed1991

Factor with erythroid burst-promoting activity in human urine unlike other hematopoietic growth factors.

A factor with burst-promoting activity (BPA) stimulates the formation of erythroid bursts in the presence of erythropoietin, acting on early erythroid progenitor cells (erythroid burst-forming units, or BFU-E). Here we investigated the biological properties of this factor partially purified from the urine of anemic patients. The human urinary factor did not cause the formation of late erythroid progenitor cells (erythroid colony-forming units, or CFU-E) or enhance such colony formation in the presence of erythropoietin. Thus, the urinary factor was a different substance from erythroid potentiating activity and from activin, which act on both BFU-E and CFU-E. The urinary factor promoted the colony formation of BFU-E from both humans and mice, but the human hematopoietic growth factors such as recombinant interleukin-3, interleukin-6, granulocyte-macrophage colony-stimulating factor, and macrophage colony-stimulating factor did not stimulate the formation of BFU-E derived colonies from mice. The results suggested that the factor in the urine of anemic patients was different from the hematopoietic growth factors identified so far.

Anemia↗
PubMed1991

[Cardiac performance before and after Jatene procedure for transposition of the great arteries: with specific reference to post-operative supravalvular pulmonary stenosis].

The cardiac performance was evaluated in patients who had received arterial switch operation (AS-op) for transposition of the great arteries (TGA) in their infancy with special attention to postoperative supravalvular pulmonary stenosis (SVPS). AS-op was performed in 36 infants; 13 with simple TGA and 23 with TGA accompanied with ventricular septal defect. Nine patients had undergone pulmonary arterial banding with systemico-pulmonary shunt. The mean age at surgery was 7 months. Postoperative catheterization was performed on average of 15 months after surgery. The end-diastolic volume (EDV) and ejection fraction (EF) of the left and right ventricles (LV, RV) were calculated from biplane cineangiograms. LVEDV and RVEDV were normalized and expressed as % of normals. SVPS was defined as peak systolic pressure gradient of 50 mmHg or higher between the RV and the pulmonary artery (PA). The mean LVEDV, RVEDV, LVEF and RVEF values were all within the normal range. Inverse correlation was observed between the peak systolic RV-PA pressure gradient and RVEF (n = 29, r = -0.84, p less than 0.001). SVPS after AS-op was observed in 8 patients (22%). Stenosis was observed at the site of anastomosis of the artery. In these cases, the diameter of the PA at the stenotic site decreased to 52% of the preoperative values. Branch stenosis of the PA was observed in 3 patients who had undergone surgery during the neonatal period. Generally, the results after AS-op were satisfactory in terms of cardiac performance. Postoperative SVPS was observed in 8 patients (22%) with decreased RVEF. Careful observations of the growth of PA after AS-op are mandatory.

Cardiac Surgical Procedures↗
PubMed1990

The role of carbohydrate in recombinant human erythropoietin.

1. Recombinant human erythropoietin has N-linked sugar [Tsuda et al., (1988) Biochemistry 27, 5646-5654]. Here we have demonstrated the presence of O-linked sugar (0.85 mol/mol erythropoietin) composed of sialic acid and Gal beta(1-3)GalNAc. 2. To investigate the role of these sugars, erythropoietins deglycosylated to different extents were prepared using specific glycosidases. Sugars are not essential for in vitro biological activity of erythropoietin, because the fully deglycosylated erythropoietin had the full activity when assayed with in vitro bioassay methods. Asialylation yielded erythropoietin with higher affinity to the receptor than the undigested hormone and therefore an increased in vitro activity. Although erythropoietin from which N-linked or total sugars were removed also had higher affinity for the receptor, their in vitro activity remained unchanged compared with that of the undigested erythropoietin for unknown reasons. On the other hand, removal of sialic acids or N-linked sugar abolished the in vivo biological activity completely, indicating that the presence of N-linked sugar with terminal sialic acids is required for the hormone to reach target sites; full deglycosylation resulted in total loss of the in vivo biological activity of erythropoietin. 3. Incubation of asialo-erythropoietin and fully deglycosylated recombinant human erythropoietin at 70 degrees C for 15 min decreased the biological activity to 35% and 11% of the initial activity, respectively, while the undigested erythropoietin lost no activity. Thus resistance of erythropoietin to thermal inactivation is largely due to the presence of sugars, and terminal sialic acids greatly contribute to the stability.

Animals↗
PubMed1989

[Clinical study of butane gas abuse: in comparison with toluene-based solvent and marihuana].

We reported 2 cases of patients who abused butane gas, toluene-based solvent and marihuana. They showed different signs in the each substance, respectively. Butane gas was easier to make visual hallucinations and distorted perception of body form, and was less potent and addictive than toluene-based solvent. Spontaneous laughter and the most amotivational state were characterized by marihuana intoxication. Alteration of auditory perception that simple music sounded wonderful was also experienced. Furthermore, the above symptoms were thought to change by the order of taking the substance. Therefore, it is needed to examine the order of the use of drugs and clarify differences of symptoms in abuse among drugs, respectively.

Adolescent↗
PubMed1988

Comparative structural study of N-linked oligosaccharides of urinary and recombinant erythropoietins.

The structures of the N-linked oligosaccharides of the urinary erythropoietin (u-EPO) purified from urine of aplastic anemic patients were analyzed and compared with those for recombinant erythropoietin (r-EPO) prepared with baby hamster kidney (BHK) cells. Asparagine-linked neutral oligosaccharides were released from each EPO protein by N-oligosaccharide glycopeptidase (almond) digestion. The reducing ends of the oligosaccharide chains thus obtained were aminated with a fluorescent reagent, 2-aminopyridine, and the mixture of pyridylamino derivatives of the oligosaccharides was separated by high-performance liquid chromatography (HPLC) on an ODS silica column. More than 8 and 13 kinds of oligosaccharide fractions for u-EPO and r-EPO (BHK), respectively, were completely separated by the one-step HPLC procedure. The structure of each oligosaccharide thus isolated was analyzed by a combination of sequential exoglycosidase digestion and another kind of HPLC with an amide-silica column. Furthermore, high-resolution proton nuclear magnetic resonance (1H NMR) spectroscopy and methylation analyses were carried out in the case of r-EPO (BHK).(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate Sequence↗
PubMed1978

[Brain abscess discovered 38 years after head injury (author's transl)].

We reported a case of delayed brain abscess following a penetrating gun-shot injury. The brain abscess surrounding retained intracranial fragments of bone and shell was found 38 years after head injury. The patient's only symptom had been minimal weakness of the right arm. This case was treated surgically with good results. The long period of silent infection was discussed.

Aged↗
PubMedDate not supplied

Incidence of stenotic lesions predicted by acute phase changes in coronary arterial diameter during Kawasaki disease.

To clarify the incidence of stenotic lesions according to the coronary arterial diameter in the acute phase. we investigated 190 patients with coronary arterial lesions who underwent an initial coronary angiogram (CAG) less than 100 days after the onset of Kawasaki disease. The largest diameters of the major branches were measured in the initial CAGs. The diameter of the large group was > or = 8.0 mm, that of the medium group was > or = 6.0 mm but < 8.0 mm, and that of the small group was > or = 4.0 mm but < 6.0 mm. There were 121 patients in the large group, 85 in the medium group, 77 in the small group. We investigated the stenotic lesions in the follow-up CAGs and evaluated the incidence of stenotic lesions in each group by the Kaplan-Meier method. The mean interval from the initial CAGs to the latest CAG was 97 months. The incidence of stenosis at 5, 10, and 15 years in the large group was 44, 62, and 74%, respectively. In the medium group the corresponding values were 6, 20, 58%, respectively. None of the patients in the small group developed stenotic lesions. Dilatation of more than 6.0 mm produces a high probability of irreversible change in the coronary arterial wall, leading to subsequent stenotic lesions.

Adolescent↗
PubMedDate not supplied

Strategy for localized stenosis caused by Kawasaki disease: midterm results of percutaneous transluminal coronary balloon angioplasty in two infants.

We report the midterm results of percutaneous transluminal coronary balloon angioplasty (PCBA) for localized stenosis (LS) caused by Kawasaki disease (KD). Two 2-year-olds, a girl and a boy, underwent PCBA for severe LS of the left anterior descending artery caused by KD. After 4 years, there was no ischemia and no significant restenosis in the target vessels. PCBA provided a good result for early appearing LS caused by KD in two small infants. The 5-years-old boy was the youngest patient to undergo percutaneous transluminal coronary rotablator. Although the postprocedure result was very effective, 1 year later asymptomatic occlusion occurred.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Two young adults who had acute coronary syndrome after regression of coronary aneurysms caused by Kawasaki disease in infancy.

We report two young adult patients who had acute coronary syndrome after regression of coronary aneurysms caused by Kawasaki disease (KD). A 26 year-old man had acute anterior myocardial infarction at midnight after drinking alcohol. He had had bilateral coronary aneurysms caused by KD at the age of 8 months. Selective coronary angiograms (CAGs) at the age of 7 years revealed regression of both coronary aneurysms. He had no symptoms until the onset of acute myocardial infarction. The other patient was a 24 year-old man diagnosed as having a subendocardial infarction. He had had bilateral coronary aneurysms caused by KD at the age of 1 year. CAGs at the age of 9 years showed that both had regressed. It should be recognized that young adults with apparently normal coronary arteries angiographically after regression of large coronary aneurysms caused by KD may occasionally have acute coronary syndromes. We suspect intimal involvement of the coronary arterial wall after regression of the large aneurysms underlies the acute coronary syndrome in adults. Risk factors for atherosclerosis must be avoided in this population.

Adult↗
PubMedDate not supplied

Direct evidence of the anterior cruciate ligament-hamstring reflex arc in humans.

It has been emphasized that the anterior cruciate ligament plays an important role in the proprioceptive feedback system. The anterior cruciate ligament-hamstring reflex has been revealed in animal experiments, but it has not been established in humans. The purpose of this study was to demonstrate direct evidence of the anterior cruciate ligament-hamstring reflex arc. Nine knees in nine healthy subjects were investigated. The anterior cruciate ligament was stimulated by the use of wire electrodes inserted using an arthroscopic technique. Electromyographic signals from the biceps femoris and the semitendinosus muscles were recorded with surface electrodes. The change in electromyographic activity was analyzed after electrical stimulation in the normal knee condition, and again after intraarticular sensation had been interrupted with a local anesthetic. After electrical stimulation, subjects demonstrated increased electromyographic activity of the hamstring muscles in the normal knee condition. This response indicates the existence of an anterior cruciate ligament-hamstring reflex arc. Conversely, there was no change in activity for the hamstring muscle in the anesthetized knee because the afferent impulse from the neural elements of the anterior cruciate ligament had been removed.

Adult↗
PubMedDate not supplied

Techniques for reducing anterior knee symptoms after anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft.

Seventy-five patients underwent unilateral anterior cruciate ligament reconstruction with an ipsilateral bone-patellar tendon-bone autograft at our institution. The graft was harvested using a two-transverse-incision technique, and patellar and tibial bony defects were repaired with cored bone grafts collected by reaming the femoral socket and the tibial socket or tunnel. We evaluated the incidence of anterior knee pain, donor site tenderness, and sensory disturbance after use of these procedures. We also analyzed the correlation between anterior knee pain and age, sex, bone plug length, range of motion, postoperative stability, patellar tendon shortening, infrapatellar nerve injury, and the size of the patellar defect. Thirteen patients reported anterior knee pain. Donor site tenderness was detected in 10 patients and was located on the inferior pole of the patella, the tibial tubercle, or both. Sensory disturbance was found over the infrapatellar nerve area in 13 patients. Statistical analysis showed that anterior instability (side-to-side difference of >3 mm) and residual patellar bony defect (depth >2 mm) were risk factors for anterior knee pain. The results of our study suggest that cored cancellous bone grafting for complete restoration of the donor site bony defects and the two-transverse-incision technique to preserve the infrapatellar branch of the saphenous nerve contribute to prevention of anterior knee symptoms.

Adolescent↗