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Biomedical subjects

S Sawada

Publications and source records attributed to S Sawada.

At least 325 records · Page 18Linked to original sources
PubMed1991

[Acute congestive heart failure due to malignant rheumatoid arthritis].

A 54-year-old woman with malignant rheumatoid arthritis was admitted with acute congestive heart failure and pulmonary hypertension. The precipitating antibody to nuclear ribonucleoprotein (nRNP) was highly positive. Her hands and feet showed typical rheumatoid deformities and Raynaud's phenomenon. In a few days her feet became to necrosis due to vasculitis. "Pulse" methylprednisolone and prednisone therapy resulted in normalization of seropositivity, and left ventricular ejection fraction with symptoms of congestive heart failure, and the elimination of ECG abnormalities. Recognition of symptoms of left ventricular dysfunction in patients with rheumatoid arthritis should prompt testing for active arteritis and/or myocarditis, because dramatic improvement may result from immunosuppressive therapy.

Antibodies, Antinuclear↗
PubMed1991

[Effects of long-term low dose radiation--relationship between chromosomal translocation and the cellular oncogenes].

To clarify the late effects of long-term exposure to low doses of radiation, chromosomal aberrations in the lymphocytes of radiological technologists (RT) were analyzed by the trypsin G-banding method. Structural aberrations were identified in 384 (2.5%) of 15,442 cells analyzed from 53 RT as compared to 177 (1.6%) of 11,136 cells from 36 healthy controls. Most of structural aberrations in both groups was translocations, and this frequency was significantly higher in the RT than in the controls. Translocations of chromosomes, such as Nos. 1, 2, 7 and 14 in RT and Nos. 1, 3, 7 and 14 in controls, was observed in over 7% of the cells. 7/14 translocations were the most frequent reciprocal translocations in RT. However, the frequency of 7/14 translocations was not significantly different between the RT and controls. In these cases, most of the break points were localized in band 14q11-12 and 7q32-36. At the chromosomal sites which were related to the sites of ski, abl, myb, mos, myc, N-myc oncogenes, very low incidences of translocation were detected in RT. However, none of the RT demonstrated abnormal clones of cells with identical chromosomal aberrations.

Chromosomes, Human↗
PubMed1991

Selective killing of Paneth cells by intravenous administration of dithizone in rats.

Paneth cells are zinc-containing cells widely distributed in Lieberkühn's crypts of intestine in a variety of species. We found that rapid selective killing of Paneth cells took place after the intravenous (i.v.) injection of diphenylthiocarbazone (dithizone), a chelator forming a zinc dithizonate complex, in the rat. As soon as 5 min after the i.v. injection of dithizone, degeneration of Paneth cells occurred. At this stage, zinc dithizonate complexes were observed as purple-red granules in bright field microscopy. Thirty to 60 min later, Paneth cells were detached from the basement membrane and shed into the cryptic lumen. After 6 h, the cell debris in the crypts was no longer seen and the crypts once housing Paneth cells were now occupied by neighbouring crypt base columnar cells. Histochemically demonstrable zinc totally disappeared. After 12-24 h, however, definite Paneth cells began to resume. Histochemical staining for zinc was again positive at the apex of these cells. One week after dithizone administration, the number of Paneth cells increased twice as much as in uninjected control and histochemical staining for zinc was highly positive. After 2 weeks, Paneth cell hyperplasia subsided. X-ray microanalysis revealed that zinc was the most abundant metal in Paneth cells. We concluded that chelation of zinc and formation of zinc-dithizone complexes in Paneth cells' cytoplasm would be responsible for the selective degeneration observed after dithizone administration.

Animals↗
PubMed1991

Endotracheal expandable metallic stent placement in dogs.

Various types of Gianturco zig-zag wire stent were implanted into the tracheas of 4 dogs to define the suitable characteristics of the endotracheal wire stent in these animals. The stents were constructed of 0.45, 0.40, and 0.33 mm stainless steel wire. The diameter of the fully expanded stents was 3 cm and their lengths were 2, 3, and 4 cm. The 2 cm stent constructed of 0.33 mm wire showed minimum pathologic changes of the trachea of the dog compared to the other stents, and at the same time had a complete covering of ciliated columnar epithelium over the stent surface.

Animals↗
PubMed1990

[Experimental study of the intraurethral placement of expandable metallic stents].

Various types of Gianturco expandable metallic stents were implanted into the urethra of four dogs in order to evaluate the suitable expandability of the stents in urethra and also to determine the effect of the stents on the urethral wall. The stent of 1.5 cm in length and constructed of 0.010 inch round stainless steel wire with twelve zigzag bends showed the suitable expandability on the canine urethra compared to the other stents. The urethra remained patent and the inflammatory changes on the urethral wall were moderately noted. No hematuria or calcifications around the stents were noted in any dogs. The experimental data showed a potential clinical application.

Animals↗
PubMed1990

[In vitro study of radiofrequency thermal angioplasty].

We performed some in vitro experiments using a radiofrequency thermal angioplasty instrument. The distribution of heat emitted from the hot tip of the device was evaluated in an agar phantom by thermography and it produced a concentric circular pattern. The temperature of the hot tip was about 290 degrees C when measured by thermocouples in the air. When the RF probe approached perpendicularly to the cadaver arterial wall, a crater with charring and coagulating necrosis was formed. However, when the RF probe traveled parallel to the arterial wall, as in normal practice, it did not seem to perforate the artery. The device could ablate non-calcified atheromatous plaque.

Angioplasty, Balloon↗
PubMed1990

Applicability of Pascal distribution to quantal analysis for non-stationary release of neurotransmitter.

In order to assess the applicability of theoretical distributions to statistical analysis of neurotransmitter release, we made mathematical approaches such as derivation of frequency-generating function of the distributions, and obtained a result that a frequency distribution of the number of quanta released by the consecutive stimulations is described by a Pascal distribution when the Poisson parameter m varies temporally according to a gamma (gamma) distribution. Therefore, if the experimentally obtained distribution fits with a Pascal distribution, this suggests that non-stationary nature of the release mechanism.

Animals↗
PubMed1990

[Self-expandable metallic stent for use in venous occlusions].

Expandable metallic stent was successfully introduced to 5 patients including idiopathic obstruction of the hepatic portion of the inferior vena cava (1 case), superior vena cava obstruction from metastatic lymphnodes swelling (2 cases) and IVC obstructions from liver metastases or lymphnodes metastases (2 cases). The obstructions were 4-14 cm long in the case of venous obstructions due to lymphnodes metastases and 2 cm long in the case of idiopathic hepatic IVC obstruction. In all cases, the stents were introduced by using 12-16 Fr catheter percutaneously without any complications. The stent used was connected up to 7 pieces by using wire struts depending length of the obstructions. However the stents connected more than 5 pieces were difficult to advance through the catheter. The patients who had been treated with stents had been free from hazardous complications such as lower extremity swelling, and pain.

Adult↗
PubMed1990

[Fundamental experiment of expansile force of expandable metallic stent].

So far expansile force of expandable metallic stent has been estimated by only wall-distending pressure P. We estimated expansile force of stent by not only P but also a force per one unit length of wire F. F corresponds to the degree of digging into the vessel wall. P and F were thought to be useful in selecting the best stent.

Elasticity↗
PubMed1990

Assignment of tyrosine resonances in the 1H-NMR spectrum of tryptophan synthase alpha-subunit. Monitoring conformational changes due to substitutions at position 49.

In order to monitor the conformational changes of tryptophan synthase alpha-subunit from Escherichia coli in solution resulting from amino acid substitutions, we have assigned the Tyr resonances in the aromatic region of the 1H-NMR spectrum to specific residues. In the spectrum of the alpha-subunit deuterated with [2,3,4,5,6-2H5]Phe and [3,5-2H2]Tyr, the C2 and C6 protons of Tyr gave completely isolated signals at acidic p2H. Some of the C3 and C5 proton resonances overlapped with each other at acidic p2H. By using a series of mutant alpha-subunits in which each Tyr was singly substituted with His or Phe, we can now assign each of seven Tyr resonances in the aromatic region to a specific residue. We have previously studied the conformational stability of a series of variant alpha-subunits at position 49 [Yutani et al. (1987) Proc. Natl Acad. Sci. USA 84, 4441-4444]. We now compare the 1H-NMR spectra in the aromatic region of the wild-type alpha-subunit and mutant alpha-subunits substituted with Phe or Gly in place of Glu-49. The results suggest that the major conformational effects of substitutions at position 49 are localized close to the position of substitution.

Binding Sites↗
PubMed1990

[Percutaneous transfemoral arterial placement of 3 Fr. balloon infusion catheter for infusion chemotherapy of liver tumors].

A 3 Fr. single lumen balloon catheter was successfully introduced for arterial infusion chemotherapy by percutaneous transfemoral arterial insertion. This balloon catheter was used combined with 6.3 Fr. outer catheter coaxially. After placing the catheter into the target artery, the balloon catheter was ruptured by injecting 1 ml contrast medium. On the other hand the balloon was made as a leak balloon catheter by a small needle puncture before use. Some merits of this system were as follows: Transarterial infusion chemotherapy can be followed immediately after making a diagnosis by transfemoral angiography. At the time of rupturing the balloon, we can see the area that must be infused under the conventional fluoroscopy. In the case of leak balloon catheter no blood regurgitation through the catheter was occurred during the procedure because of elasticity of the rubber. In 40 patients having liver tumor we performed this method combined with continuous infusion of 5-fluorouracil for 3 to 5 weeks and also once a week intra-arterial administration of mitomycin C and adriamycin. In some patients hyperthermia therapy was also carried out for the purpose of potentiation of cellular chemosensitivity by low temperature hyperthermia. The result of this therapy was as follows: CR; 10.3%, PR; 20.7%, NC; 63.9% and PD; 5.1%. No serious complications were encountered in our series except for some minor arterial troubles caused by catheter tip.

Adolescent↗
PubMed1990

[Experimental study of endotracheal expandable metallic stent placement].

Various types of Gianturco zig-zag wire stents were implanted into the trachea of three dogs in order to evaluate the suitable conditions of the endotracheal wire stent. The stents were constructed of 0.018, 0.016 and 0.013 inch stainless steel wire respectively. The relaxed diameter of the stents was 3.0 cm and their length were 2 cm, 3 cm, and 4 cm respectively. The stent of 2 cm in length and constructed of 0.013 inch showed minimum pathologic changes to the trachea of the dog compared to the other stents, and also showed the covering of ciliated, columnar epithelium over the stent surface. The experimental data showed that it was possible to use the stent in the tracheobronchial tree of dogs and also showed a potential clinical application.

Animals↗
PubMed1990

Improvement in rest and exercise-induced wall motion abnormalities after coronary angioplasty: an exercise echocardiographic study.

Exercise echocardiography was performed in 36 patients to evaluate functional improvement after coronary angioplasty. Thirty-one patients (86%) had provokable ischemia before angioplasty including 22 with an abnormal exercise electrocardiographic test (angina or ST depression), 25 with an abnormal exercise echocardiogram (exercise-induced wall motion abnormalities) and 16 with both tests abnormal. Nineteen patients had no induced ischemia after angioplasty. Seventeen (47%) continued to have ischemia that was limited in 12 to exercise-induced wall motion abnormalities, which were less severe compared with those of preangioplasty studies. Fifteen (65%) of 23 patients had improvement in rest wall motion abnormalities after angioplasty. The rest to immediate postexercise change in global wall motion score was significantly improved after angioplasty. The change in regional wall motion score was significantly improved after angioplasty in patients with single vessel right or left circumflex coronary artery disease and approached significant improvement (p = 0.06) in those with single vessel disease of the left anterior descending coronary artery. Exercise echocardiography improves the sensitivity of functional testing for ischemia, aids in localizing the ischemic zone and documents improvement in regional function after coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1990

Phosphorylcholine antibodies in pulmonary infection.

Phosphorylcholine (PC) antibodies in serum from patients with pulmonary infection, and from normal individuals, were studied. Anti-PC antibodies were detectable in the serum from normal individuals at mean concentrations of 320 micrograms/ml for the IgG class and 110 micrograms/ml for the IgM class. Concentrations of anti-PC antibodies which were higher than normal for both the IgG and IgM classes were observed in the serum in pulmonary infection (1,440 micrograms/ml and 210 micrograms/ml, respectively). Despite the significant difference in the concentration of anti-PC antibodies, the PC-specific B cell precursor frequency in the peripheral blood lymphocytes showed no difference between normal individuals and the patients with pulmonary infection, or between the acute phase and the chronic phase in a single patient with chronic pulmonary infection. Serologically, the purified IgG anti-PC antibody did not share the cross-reactive idiotype of TEPC 15, which is the most common idiotype of the murine anti-PC antibodies. However, the purified IgM anti-PC antibody expressed a very weak cross-reactive idiotype of TEPC 15. It appears from these studies that human anti-PC antibodies may play an important biological role in pulmonary infection by microorganisms which possess a PC determinant.

Acute Disease↗
PubMed1990

Increased plasma fibronectin in patients with systemic lupus erythematosus.

To add to our knowledge of collagen diseases, plasma fibronectin (FN) in patients with systemic lupus erythematosus (SLE) has been measured, and it was determined that the plasma FN value in those with SLE was 454 +/- 36 micrograms/ml, is significantly higher than the FN value in normal subjects (234 +/- 21 micrograms/ml) than that of patients with FN value of patients with active SLE was significantly higher (591 +/- 46 micrograms/ml) that of the patients with non-active SLE (287 +/- 31 micrograms/ml). The plasma FN value of SLE patients was also seen to be associated with the peripheral blood platelet count and with the dose level of the corticosteroid hormone administered to patients. In active SLE patients, it was similarly found that the plasma FN value had a significant correlation with the peripheral blood lymphocyte count and with the dose level of the corticosteroid hormone given to patients. Since the plasma FN value is known to be high in untreated SLE patients, it was felt that the increase of the FN value in SLE patients is not due to the effect of the corticosteroid but to the disease itself.

Adolescent↗
PubMed1990

Functional T-cell subset defined by cluster formation with EB virus transformed B-cells.

This study compares functional properties of T-cells capable of forming clusters with EB virus transformed B lymphoblastoid cells (B-LCL) as accessory cells (A-cells). T-cell functional properties examined include T-cell activation, interleukin 2 (IL-2) production and cell proliferation. In addition, functional properties were compared with the presence or absence of surface markers. T-cells were divided into those that formed clusters with the B-LCL (clustered T-cells) and those that failed to form clusters (nonclustered T-cells). Each subpopulation of T-cells was also incubated with B-LCL and Concanavalin A (Con A) to test for changes in proliferative capabilities. Functional studies indicated that IL-2 activity was higher in the culture supernatant fluids from clustered T-cells than nonclustered T-cells. Spontaneous proliferation of clustered T-cells was equivalent to proliferation of clustered T-cells stimulated with Con A or human IL-2. However, weak spontaneous proliferation by non clustered T cells was enhanced after culturing with Con A or human IL-2. The nonclustered T-cells also produced less IL-2 in cultures containing both B-LCL or Con A. Quantification of T-cell surface markers showed that the expression of Tac antigen was greater on the clustered T-cells than on the nonclustered T-cells. These data suggest that functionally different T-cell subsets can be identified and isolated by their capacity to form clusters with B-LCL A-cells.

Antigen-Presenting Cells↗
PubMed1990

Colony promoting activity: differences from interleukin-3 and similarities to interleukin-6.

The supernatant of long-term bone marrow culture contains colony promoting activity (CPA) which does not have granulocyte-macrophage colony stimulating activity (CSF) but which enhances granulocyte-macrophage (GM) colony formation in the presence of CSF. CPA might consist of IL-3 or IL-3-like activity, since CPA stimulates proliferation and differentiation of more immature cells to CSF-responding granulocytes-macrophage progenitors (GM-CFC), and since IL-3 also stimulates immature hemopoietic cells to proliferate and differentiate to functional blood cells. IL-1 and IL-6 are also known to enhance GM colony formation. One or both of these molecules can accordingly be another candidate for CPA. In the present study, GM-CSF activity of IL-3 was dependent on the batch of serum: it was negative in the presence of fetal calf serum, but positive in the presence of horse serum. In contrast, GM-CSF and CPA showed no such dependence on the batch of serum. The addition of IL-3 to GM colony assay system did not enhance but rather suppressed GM colony formation. The supernatant of long-term bone marrow culture which contains substantial levels of CPA did not stimulate proliferation of IL-3 dependent DA-1 cells, but facilitated the proliferation of IL-6 dependent, MH60.BSF2 cells. No detectable level of IL-1 activity was found in the supernatant. These results indicate that CPA is different from IL-1, IL-3 or GM-CSF, but similar to or the same as IL-6.

Animals↗