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Biomedical subjects

K Sawada

Publications and source records attributed to K Sawada.

At least 253 records · Page 14Linked to original sources
PubMed1993

[Clinical application of a third generation lithotripter (Therasonic) for upper urinary tract calculi].

A third generation lithotripter (THERASONIC Lithotripsy Treatment System) was used for disintegration of upper urinary tract calculi. A total of 115 patients was treated at Miki Municipal Hospital, 54 with renal calculi, 8 with UPJ calculi, 30 with upper and 23 with lower ureter calculi. The stone-free rate one month after treatment was 89%, 88%, 90% and 100% for renal, UPJ, upper ureter and lower ureter calculi, respectively. As for side effects, we experienced two cases of perinephric hematoma which were treated conservatively. However, we encountered no other severe complications. These findings clearly indicated that the THERASONIC lithotripter is highly useful for disintegration of calculi of the upper urinary tract.

Adolescent↗
PubMed1992

Changes in thrombomodulin level in plasma of endotoxin-infused rabbits.

Changes in the plasma thrombomodulin (TM) level were examined in endotoxin-infused rabbits. The plasma TM level in normal rabbits was 143.8 +/- 8.4 ng/ml (n = 67) and the molecular weight of the major TM was about 55 kd. Endotoxin (lipopolysaccharide, LPS, E. Coli B8:0127) was intravenously infused. LPS infusion increased the plasma TM level dose-dependently between 0.2 mg/kg and 5 mg/kg. When 5 mg/kg LPS was infused, the plasma TM level started to increase immediately and was 2.3 times higher than the control value within 1 hr. The molecular weight of the major TM was about 75 kd. This rapid increase in TM occurred before the decrease in fibrinogen content and the prolongation of prothrombin time. To examine the effect of circulating leukocytes on the TM increase in endotoxin-infused rabbits, 5 mg/kg LPS was infused into rabbits with leukocytopenia induced by X-ray irradiation. The maximum plasma level of TM was significantly lower than in the untreated rabbits given LPS. These data suggest that the increase in plasma TM is caused by LPS-stimulated leukocyte's prior to hemostaseological changes. It is well known that endothelial cells can be injured by stimulated leukocytes, so this increase in plasma TM probably reflects the deterioration of endothelial cells. This deterioration decreases the ability of endothelial cells to inhibit thrombosis, which would, in turn, contribute to the development of disseminated intravascular coagulation in endotoxin-infused rabbits.

Animals↗
PubMed1992

Selective removal of anti-acetylcholine receptor antibody in the low temperature operation of membrane plasma fractionation.

The removal of anti-acetylcholine receptor antibody (anti-AChR Ab) by the plasma fractionator, Kuraray EVAL 2A, was measured as a function of the filtration temperature (4 and 37 degrees C). Plasmas procured from eight myasthenia gravis (MG) patients undergoing routine plasma exchanges (PE: membrane plasma filtration: n = 4, and centrifugation: n = 4) were used in the studies. Plasma flow rate was 20 ml/min, and plasma perfusion in single pass was terminated when the transmembrane pressure of the filter reached 300 mm Hg. Solute concentration data from before and after perfusion were used to assess the sieving coefficient (SC) of each solute. Results show that the SCs for anti-AChR Ab and albumin were significantly (P < .0002) lower at 4 degrees C (0.15 and 0.52, respectively) as compared to 37 degrees C (0.44 and 0.72, respectively). The SC of anti-AChR Ab (0.15) was significantly lower than the SC of IgG (0.42; P < .006) at 4 degrees C, even though it also belongs to the IgG class. The ratio of the SC of anti-AChR Ab to albumin at 4 degrees C (0.29) was significantly lower than that at 37 degrees C (0.57; P < .003). These data indicate that the selectivity of removal of anti-AChR Ab from albumin is higher at 4 degrees C than that at 37 degrees C. The volume treated at 4 degrees C was significantly lower than that treated at 37 degrees C, and it was less than that required for a clinical treatment; however, it was shown that filter backwashing is possible without loss of solute removal selectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1992

Backwashing procedure for on-line reuse of a plasma fractionator in cryofiltration.

During membrane plasma fractionation therapy there are reported incidences of membrane plugging requiring the corrective actions of either filter replacement or backwashing (BW) in order to continue the treatment. In this preliminary study, a simple BW procedure to allow for on-line reuse of the filter (Asahi AP06M) during the treatment was evaluated to assess its efficacy and safety in cryofiltration (CF). Evaluations were carried out on two patients treated for rheumatoid arthritis. Seven tests, each using 1 L or 2 L warmed saline as a BW solution were performed to evaluate the decrease of the transmembrane pressure (TMP) between just before and after backwashing and TMP change during cryofiltration procedures between before and after backwashing. Sieving coefficients of total protein, albumin, immunoglobulins (G, M, A), fibrinogen, and rheumatoid factor were also calculated at 1,000 ml plasma volume processed. Results showed statistically significant decreases of TMP from 300 mm Hg to 70 mm Hg between just before and after both backwashing procedures, and that there were no significant changes in the TMP increase during the cryofiltration procedure between pre- and post-BW. The protein sievings were not significantly affected by BW. The use of a second liter for rinsing did not reduce the inlet pressure further suggesting that 1 L BW was adequate. The accumulated solutes did not affect significantly the effective mean pore size. The BW procedure did not affect the overall patient safety during therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis, Rheumatoid↗
PubMed1992

Teratocarcinoma F9 cells induced to differentiate with sodium butyrate produce both tissue-type and urokinase-type plasminogen activators.

Sodium butyrate (NaB) can induce teratocarcinoma cell differentiation as retinoic acid (RA). However, the function of these two agents seems to be a little different [Kosaka et al., Exp Cell Res, 192:46-51, 1991]. F9 cells treated with NaB synthesize both tissue-type (tPA) and urokinase-type (uPA) plasminogen activator, though RA induces only tPA production. Urokinase-type PA is demonstrated to exist in association with membrane and to localize its activity to the close environment of the cell surface. This may cause the specific cell morphology and characteristics of differentiated F9 cells induced with NaB.

Animals↗
PubMed1992

Characterization of male meiotic germ cell-specific antigen (Meg 1) by monoclonal antibody TRA 369 in mice.

We have identified a male meiotic germ cell-specific antigen (Meg 1) with monoclonal antibody (mAb) TRA 369 in mice. The Meg 1 antigen was strongly expressed in specific steps of meiotic germ cells from pachytene spermatocyte to early spermatid, and not in other germ cells or somatic cells. Immunohistochemical examination revealed that the antigen was localized to the cytoplasm and was not distributed in the nucleus or on the cell surface. This antigen was demonstrated to have a molecular weight of 93 kDa and an isoelectric point of 5.2 by Western blotting. This molecule was first detected in the testis of 13-day-old mouse when pachytene spermatocytes first appeared. Thus this is a differentiation-specific antigen in male meiotic germ cells, and mAb TRA 369 is a useful tool to study the regulation of germ cell differentiation and to define germ cell development in a molecular level.

Animals↗
PubMed1992

A simple assay to detect endothelial cell injury; measurement of released thrombomodulin from cells.

A simple assay to determine the degree of endothelial cell injury has been developed using released thrombomodulin as the index. Thrombomodulin is a cell surface protein on endothelial cells which is released from the cell upon injury. In this assay, bovine arterial endothelial cells were cultured in serum free medium with the test substances and the amount of thrombomodulin released into the culture medium was measured by enzyme immunoassay. Substances which are known to injure cells such as H2O2, prostaglandin A2, lipopolysaccharide, and elastase released significant amounts of thrombomodulin. The sensitivity of this assay for mild injury was superior or at least equal to the traditional 51Cr release method. Since this method does not require the use of radioisotopes, it seems to be advantageous and suitable for the detection of endothelial cell injury during routine examination.

Animals↗
PubMed1992

Crystallin gene expression in the process of lentoidogenesis in cultures of chicken lens epithelial cells.

One alpha B- and three different beta-crystallin cDNA clones were isolated from a chicken lens cDNA library by using anti-crystallin antibodies. The sequence of alpha B-crystallin cDNA showed more than 70% homology with exons of alpha B-crystallin genes of the human and hamster. Two beta-crystallin cDNAs showed almost identical sequences with previously reported chicken beta B1- and beta A3/A1-crystallin genes. The remainder showed 80% homology of sequence with bovine beta B2-crystalline cDNA. Using these newly cloned cDNAs, in addition to cDNAs of alpha A- and delta-crystallin, we examined the expression pattern of these crystallins in the process of lentoidogenesis of cultured lens epithelial cells of the chicken. All crystallins except beta-crystallins were expressed through the period of cell culture, but three beta-crystallins were expressed only after the confluent stage. These results suggest that: (1) alpha A-, alpha B- and delta-crystallin cDNAs can be used to detect differentiation of the lens epithelial cell; and (2) beta-crystallin cDNAs are superior in the detection of chicken lens fibre differentiation in vitro to delta-crystallin cDNA, which is ectopically expressed by various non-lenticular tissues.

Amino Acid Sequence↗
PubMed1992

Sexually dimorphic duct system of the submandibular gland in mouse with testicular feminization mutation (Tfm/Y).

The X-linked testicular feminization mutation (Tfm/Y) in the mouse is characterized by androgen insensitivity of the target cells. The aim of this study was to examine sexually dimorphic development of the submandibular gland of Tfm/Y mutant mice in comparison with those of wild-type male, wild-type female and heterozygous Tfm female mice. In either 30- or 90-day-old wild-type male mice, the granular convoluted tubules (GCT) of the glands were more developed, and the relative occupied areas (ROA) of GCT were superior to those of the age-matched wild-type and heterozygous Tfm females. In androgen-insensitive Tfm/Y mice, the glandular structures rather resembled the female glands, showing lower values of the ROA of the GCT. Sex differences in the mitotic rate were observed at 30 days of age, being significantly higher in the wild-type male GCT than in the female GCT. Thereafter, the mitotic rate of the wild-type male GCT declined to the female levels by 90 days of age. The mitotic rate of GCT in Tfm/Y mutants was as low as those of the females during observation periods. An other three regions, the acini, the intercalated ducts and the excretory striated ducts, were not significantly different in either the ROA or the mitotic rate among wild-type males and females, and Tfm/Y. On the other hand, either the ROA or the mitotic activity of GCT of the glands in Tfm/Y mutants was completely unaffected by 5 alpha-dihydrotestosterone (DHT).(ABSTRACT TRUNCATED AT 250 WORDS)

Androgen-Insensitivity Syndrome↗
PubMed1992

Imidazo[1,2-alpha]pyridines. III. Synthesis and bradycardic activity of new 5-imidazo[1,2-alpha]pyridin-6-ylpyridine derivatives.

Structural modification of the cardiotonic agent, loprinone (E-1020, 1), suggested by data that it has a less positive chronotropic effect than milrinone (15), led us to find novel bradycardic agents that were structurally different from homoveratryl amine derivatives. Alkyl-oxy, -thio, and -amino derivatives at the 2-position of the pyridine ring of 1 produced bradycardic activity without a significant effect on blood pressure and myocardial contractility. Aryloxy analogues also decreased heart rate, and members with an electron-withdrawing group at the ortho position of the phenyl ring showed higher activity. Replacement of the imidazo[1,2-alpha]pyridine with pyridine resulted in diminished activity. The mechanism of bradycardic activity of these compounds seems to be direct action on the sinus node.

Animals↗
PubMed1992

[Effects of the new cardiotonic agent loprinone hydrochloride (E-1020) on left ventricular diameter in normal and experimental heart failure dogs and its action potential characteristics in isolated guinea pig cardiac muscles and sinus nodes].

In anesthetized dogs, loprinone hydrochloride (LP, 10 approximately 100 micrograms/kg, i.v.) dose-relatedly increased cardiac contractility (LV dP/dt max), enhanced cardiac index and decreased systemic vascular resistance with relatively small reduction in mean aortic pressure (MAP) and a mild increase in heart rate (HR). LP also decreased left ventricular internal diameter (ID), increased fractional shortening (LVFS) and caused a leftward shift and an increase in the slope of the LV end-systolic pressure-ID relation. In the heart failure models induced by propranolol, LP rapidly reversed the cardiac depression and the enlargement in cardiac size. The extent of changes in MAP and HR by LP was smaller than those observed with several other cardiotonic agents. In guinea pig cardiac muscles, LP (10(-6)-10(-4) M) produced a concentration-related increase in contractile force and the maximum rate of rise of Ca(2+)-action potential. In the sinus nodes, LP induced a concentration-related decrease in action potential duration and increase in the slope of slow diastolic depolarization, resulting in an increase in beating rate. These influences of LP on sinus nodes were smaller than those of milrinone. These results indicate that LP increases LVFS, reduces cardiac size and improves the heart failure due to its cardiotonic and vasodilating properties. Moreover, electrophysiological studies suggest that at least a part of the lower chronotropic effects of LP may be due to the mildness of its direct stimulating effects on sinus nodes.

Action Potentials↗
PubMed1992

[Human parvovirus-induced transient anemia and leukopenia after delivery].

A 30-year-old female at 27 weeks' gestation, was hospitalized on September 24 1990 because of the premature rupture of the amniotic sac. She underwent Caesarean section on the same day with 700 ml blood loss, but no blood transfusion was required. For several days after the operation, her hemoglobin level remained 7.8 g/dl and did not increase significantly in spite of parenteral iron therapy. On the 9th postoperative day, chills and pyrexia developed with leukopenia. Bone-marrow aspiration revealed severe erythroblastopenia with giant proerythroblasts, suggesting recent HPV infection, which was confirmed by the presence of anti-HPV IgM and HPV antigen by ELISA. The hemoglobin level gradually decreased to 6.0 g/dl by the 21st day, then began to increase rapidly. The serum of acute-phase containing HPV antigens inhibited BFU-E and CFU-E but not CFU-GM. The serum of convalescent-phase inhibited neither erythroid colony growth nor myeloid colony growth. These results indicate that the inhibitory effect of HPV in colony assay is highly specific for erythropoiesis and that HPV play a role in transient cessation of erythropoiesis. The reason, however, for leukopenia in HPV infection remained unclear. This case shows that HPV infection may induce severe hematological disorders even in normal person under erythropoietic stress.

Adult↗
PubMed1992

[Antibody titer to streptococcal and staphylococcal L-form in Behçet's disease and other uveitis].

The antibody titer in serum to Streptococcus pyogenes L-form and Staphylococcus aureus L-form were determined by enzyme-linked immunosorbent assay in 28 patients with Behçet's disease, 31 patients with other uveitis (sarcoidosis: 10, Harada's disease: 5, tuberculosis: 4, rheumatoid arthritis: 4, lues: 2, juvenile rheumatoid arthritis: 2, herpes simplex: 2, trauma: 2) and 16 healthy normal controls. All L-forms were induced by the penicillin disk method. The antibody titer to Streptococcus pyogenes L-form in Behçet's disease was lower than that of other cases of uveitis and controls, and showed significant differences between controls, rheumatoid arthritis, sarcoidosis, tuberculosis and Harada's disease by the Student's t-test. The antibody titer to Staphylococcus aureus L-form in Behçet's disease showed no difference between controls and other cases of uveitis. In each uveitis and controls, and between active and inactive stages of all uveitis, there were no differences between titers. In Behçet's disease, antibody formation to Streptococcus pyogenes L-form may be specifically disturbed.

Antibodies, Bacterial↗
PubMed1992

[Adequate Ca level for dialysis patient (study on medical therapy for secondary hyperparathyroidism in dialysis patient)].

We evaluated our medical therapy of secondary hyperparathyroidism (2 degrees HPT) in dialysis patients. Ten hemodialysis patients with 2 degrees HPT (PTH-C; higher than 10ng/ml) were treated with vitamin D3, large amounts of phosphate binders and calcitonin and data over three years were examined. Our data showed that 2 degrees HPT is manageable by medical therapy. Furthermore, we suggest that the adequate Ca level for dialysis patients is to maintain the Ca (mEq/1) xP (mg/dl) at less than = 35. When plasma P is less than 6mg/dl. The maintenance of this Ca level successfully treated 2 degrees HPT, and this prevent the appearance of renal osteodystrophy (ROD) in dialysis patients.

Adult↗
PubMed1992

[Two cases of acute myocardial infarction with simultaneous occlusions of two main branches].

Acute myocardial infarction with simultaneous occlusions of two main branches is very rare, and it is difficult to presume it before performing emergent CAG. We encountered two such cases recently. Case 1 was a 77 year-old woman. She was admitted to our hospital because of anterior chest pain. Emergent CAG disclosed complete occlusions of RCA-Segment 3 and LAD-Segment 7. ICT improved both of them to 90% stenoses. Case 2 was a 58 year-old man. He was admitted to our hospital because of upper abdominal pain. Emergent CAG disclosed complete occlusions of RCA-Segment 2 and LAD-Segment 6. ICT improved the former to 99% stenosis, and the latter recanalized. Myocardial dual scintigrams performed during the acute periods showed findings which were consistent with simultaneous occlusion of the two main branches in both cases. We could consider such reasons as coronary vasospasm, state of hyper-coagulability at the onset of myocardial infarction and depression of coronary pressure etc as possible causes of these cases.

Aged↗
PubMed1991

Purification of human marrow progenitor cells and demonstration of the direct action of macrophage colony-stimulating factor on colony-forming unit-macrophage.

To facilitate the investigation of the direct interaction between hematopoietic progenitors and colony-stimulating factors, we have developed a method to purify human marrow progenitor cells. Using density centrifugation, negative panning with concanavalin A coated plates, positive selection of CD34-positive cells with immunomagnetic microspheres, overnight adherence to a plastic dish, negative selection with a panel of monoclonal antibodies, and density centrifugation, human marrow progenitor cells were purified from 1.5% to 53.2%, a 42-fold purification, with a 4.8% yield. The purified cells consisted of 38% erythroid, 9% colony forming unit-granulocyte (CFU-G), 29% CFU-macrophage (CFU-M), 12% CFU-eosinophil/basophil (CFU-Eo/Ba), and 4% CFU-mix. The purified cells cultured in serum-free fibrin clots with recombinant human macrophage colony-stimulating factor (rM-CSF) for 14 days developed a pure population of CFU-M colonies. An appearance of CFU-M colonies was present after the addition of 1 U/mL of rM-CSF and the maximum stimulation was found at 100 U/mL. When the purified cells were cultured in serum-free medium with rM-CSF in a limiting dilution assay and the percentage of nonresponder wells for CFU-M colonies was plotted against cell concentration, serum-free cultures yielded a straight line through the origin, indicating that CFU-M development did not depend on accessory cells and that rM-CSF acted directly on the CFU-M.

Antigens, CD↗
PubMed1991

Postnatal vaginal nodules induced by prenatal diethylstilbestrol treatment correlate with later development of ovary-independent vaginal and uterine changes in mice.

Pregnant ICR/JCL mice were given 4 daily subcutaneous injections of 0.2-2000 micrograms diethylstilbestrol (DES) starting on day 15 of gestation. Offspring of mothers given DES were killed at 1-10 days of age and examined for nodules of enlarged polygonal cells under the epithelium of the Müllerian (upper) vagina. Some offspring were ovariectomised at 30 days and killed at 120 days. The nodules which appeared in the prenatally DES-exposed mice (2-2000 micrograms/day) at 3-7 days were not connected with the epithelium of the sinus vagina and reacted positively to an antibody to epidermal growth factor. Nodule formation may prove to be prodromic of later ovary-independent vaginal changes in the DES-exposed mice. Epithelial stratification (2-2000 micrograms/day) and downgrowths and/or pegs (20-2000 micrograms/day) occurred in vaginae of ovariectomized mice exposed prenatally to DES; however, adenosis-like lesions occurred only in the offspring of mothers given the highest prenatal injections of 2000 micrograms DES. Wolffian remnants and hypospadias (2-2000 micrograms/day) were also encountered in the DES-exposed mice. Ovary-independent stratification of the uterine epithelium (20-2000 micrograms/day) and disorganization of the circular musculature (2-2000 micrograms/day) were also observed in the DES-exposed mice. None of these changes was found in ovariectomised 0.2 micrograms DES-exposed and control mice.

Animals↗