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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 829 records · Page 46Linked to original sources
PubMed1991

Measurement of plasma free steroids by direct radioimmunoassay of ultrafiltrate in association with the monitoring of free components with [14C]glucose.

We describe a modified method of centrifugal ultrafiltration using the Grace MPS-3 device for the measurement of plasma free (unbound) steroids (cortisol, testosterone, estradiol, and prednisolone). Plasma was incubated with [14C]glucose to monitor the movement of free components, applied to the MPS-3 and centrifuged. Steroid concentration of ultrafiltrate was directly measured by radioimmunoassay, and multiplied by the ratio of [14C]glucose count (dpm) in plasma to [14C]glucose count (dpm) in ultrafiltrate. The data by this method correlated well with those obtained by equilibrium dialysis. Our results of free steroid in healthy volunteers and patients with various diseases were comparable with the previously reported values. This procedure showed the advantages of small sample volume, rapid separation and the ability to process a large number of samples in a single run.

Adolescent↗
PubMed1991

Liver and muscle-fat type glucose transporter gene expression in obese and diabetic rats.

In order to investigate the regulation of glucose transporter gene expression in the altered metabolic conditions of obesity and diabetes, we have measured mRNA levels encoding GLUT2 in the liver and GLUT4 in the gastrocnemius muscle from various insulin resistant animal models, including Zucker fatty, Wistar fatty, and streptozocin(STZ)-treated diabetic rats. Northern blot analysis revealed that GLUT2 mRNA levels were significantly (P less than 0.001) elevated in 14 wk Zucker fatty and Wistar fatty rats relative to lean littermates but were similar in these two groups at 5 wk of age. Furthermore, there was significant increase (P less than 0.01) in GLUT2 mRNA levels in STZ diabetic rats at 3 wk after treatment. GLUT4 mRNA levels were not significantly different between control and insulin resistant rats in all animal models. These results indicate that neither hyperinsulinemia nor hyperglycemia affects GLUT4 mRNA levels in the muscle. However, GLUT2 mRNA levels in the liver were elevated in obesity and diabetes, although this regulatory event occurred independently from circulating insulin or glucose concentrations.

Animals↗
PubMed1991

Expression of the chicken 'delta 2-crystallin' gene in mouse cells: evidence for encoding of argininosuccinate lyase.

In the chicken genome, downstream from the delta 1 gene, encoding delta-crystallin, a highly homologous gene called delta 2 is found, but neither its expression nor its function has been clarified. Close similarity of the delta 2 gene to mammalian argininosuccinate lyase (ASL)-encoding genes in organization and deduced amino acid sequence of the encoded protein suggested that this gene may encode chicken ASL. To test this possibility, we cloned the delta 2 gene on a plasmid, introduced it into mouse cells, and assessed expression and ASL activity in comparison with delta 1. We found that delta 2 was expressed well in fibroblastic L cells, which resulted in synthesis of a protein with a size (50 kDa) and antigenicity very close to delta-crystallin, but it was repressed in lens cells in which expression of delta 1 was activated. Transfectant L cell lines expressing delta 2 exhibited significantly higher ASL activity than those without. We conclude that the delta 2 gene codes for chicken ASL, but has a tissue specificity distinct from delta 1 in its expression.

Animals↗
PubMed1991

Tissue distribution and species difference of the brain type glucose transporter (GLUT3).

The complementary DNA for the human brain type glucose transporter (GLUT3) was used to determine its tissue specific expression in human, monkey, rabbit, rat, and mouse. Under high stringent conditions, 4.1 and 3.2 kilobase (kb) GLUT3 transcripts in monkey and a single 4.1 kb GLUT3 mRNA in rabbit, rat, and mouse were detected by RNA blot analysis. Although the GLUT3 transcripts were widely distributed, as are the erythrocyte type glucose transporter (GLUT1) transcripts, this mRNA is most abundant in the brain. However, the relative abundance of GLUT3 mRNA in the various regions of the monkey brain shows a different pattern from that of GLUT1 mRNA: GLUT3 is most highly expressed in the frontal lobe of the cerebrum, whereas GLUT1 is most abundant in the basal ganglia and the thalamus. Moderately higher GLUT3 mRNA levels were detected in the parietal lobe of the cerebrum, hippocampus, and cerebellum than the levels of GLUT1 transcripts. We also detected GLUT3 mRNA in adult human psoas major muscle, although it has been reported that the GLUT3 gene is scarcely expressed in adult human skeletal muscle of the thigh. In addition, in the rat and the mouse, no transcripts of the GLUT3 gene were detected in liver, kidney, small intestine, skeletal muscle, or fat besides in brain. Thus, the expression of the GLUT3 gene seems to be restricted to the brain in rodents. These results suggest that the expression of GLUT1 and GLUT3 genes might be regulated by different mechanisms.

Animals↗
PubMed1991

The pharmacokinetics of plasma total and free prednisolone during an alternate-day regimen.

To determine the pharmacokinetic changes of prednisolone associated with an alternate-day regimen, 12 patients with various diseases were studied longitudinally. There were 9 patients (6 with systemic lupus erythematosus, 2 with sarcoidosis and one with polymyositis), who were treated with prednisolone (daily period) and subsequently put on an alternate-day regimen (alternate-day period). In 2 of the other patients (one with systemic lupus erythematosus and one with multiple sclerosis), the alternate-day regimen was preceded by the daily regimen, and subsequently an intermittent regimen consisting of 4 consecutive days on therapy and 3 days off therapy was followed. In the remaining patient with systemic lupus erythematosus, the treatment with the alternate-day regimen was initiated and followed throughout the treatment period. The mean duration and the mean total administered dose during the study were 1.1 months and 1.9 g in the daily period, and 7.8 months and 7.7 g in the alternate-day period. The test was done and blood was drawn for 6 hours after an intravenous administration of 20 mg prednisolone (0.36 mg/kg on the average) at the end of the respective regimen periods. In the daily period and the on-day of the alternate-day regimen, the pharmacokinetic study of iv prednisolone injection was done before the ingestion of oral prednisolone. The off-day test was done the next morning of the on-day. Plasma total and free prednisolone concentrations were measured by RIA. On-day and off-day tests in the alternate-day period were performed during the same week. The mean half life of both total and free prednisolone was prolonged significantly in the daily period and during the on-day and off-day of the alternate-day regimen compared with the pretreatment values. The mean metabolic clearance rates (MCR) of both total and free prednisolone decreased significantly in the daily period and during the on-day and off-day of the alternate-day period in comparison with the pretreatment values. No significant difference was found between either mean half life or MCR during the on-day and off-day of the alternate-day period. These findings were in contrast with our previously observed prednisolone pharmacokinetics during the intermittent regimen (4 days on therapy and 3 days off therapy within one week), in which pharmacokinetic parameters during the on-day (after 3 days of prednisolone ingestion) and off-day (after 3 off-days of prednisolone ingestion) periodically changed and were similar to those in the pre-treatment period and during the daily therapy period, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

A random walk method for percutaneous drug absorption pharmacokinetics: application to repeated administration of a therapeutic timolol patch.

A random walk method for predicting percutaneous drug absorption pharmacokinetics was proposed. The profiles predicted by this method were compatible with those predicted by the analytical method. The random walk method is particularly useful for predicting complex processes such as repeated topical application of a drug. The amount of a drug released into skin from four therapeutic timolol patches was measured when the patches were serially applied for 2.5 h each on the same site of six healthy male volunteers. On the average, 33.2, 23.4, 15.1, and 16.5% of the applied dose was released into skin from the first, second, third, and fourth patches, respectively. This pattern was comparable with the predicted profiles (43.9, 30.2, 24.4, and 21.1%) of amounts of drug which were expected to be released from the first to fourth patches into skin, respectively. The estimation method for the normalized skin-capillary boundary clearance is also described and applied in examining the percutaneous absorption of timolol. The estimated value for this parameter was much greater than the diffusion parameter, indicating that the removal process of timolol by the local circulation is much faster than the diffusion process through skin.

Administration, Cutaneous↗
PubMed1991

Treatment of osteoarthritis of the knee with heel wedges.

Sixty-two patients with early medial compartment osteoarthritis of the knee were treated with lateral heel wedges and followed for from 7 years and 5 months to 12 years. Those who were treated with heel wedges and analgesics showed a significantly greater improvement in pain score than those treated with analgesics only, but not in the walking ability score at the second follow up. The lateral heel wedge had no effect on the progress of the radiographic changes. The lateral heel wedge is useful for patients with early medical compartment osteoarthritis provided it is used with an understanding of the indications and its limitations.

Adult↗
PubMed1991

Serum-free medium for murine and human lymphoid and hybridoma cell lines.

We established a serum-free medium of low protein content (125 micrograms/ml) TYI 100, consisting of three hormones and five growth factors for the growth of lymphoid and hybridoma cell lines. In TYI 100 medium, mouse and human hybridomas grew equally well as in RPMI 1640 supplemented with 10% fetal bovine serum (10% FBS) without adaptation to the serum-free medium. TYI 100 medium allowed several passages of mouse hybridoma lines and the total cell number was more than in 10% FBS. TYI 100 medium also supported growth of myelomas and anchorage dependent cell lines, Bowes and CHO, well. TYI 100 medium is composed of inexpensive supplements and is therefor applicable to large scale culture.

Animals↗
PubMed1991

Solid cell nests of the thyroid gland.

The histogenesis and clinical significance of solid cell nests (SCN) of the thyroid are not fully understood. From August 1987 to December 1989 a total of 2544 patients with thyroid and parathyroid diseases underwent surgery at Ito Hospital, and SCN were revealed within the thyroid parenchyma in 21 (0.8%). Distribution of SCN was not limited to the upper one-third of the lateral lobe, and SCN were found even in the isthmus lobe. In 5 cases microcysts were also noted within SCN, and their content was thought to be acidic proteoglycan. Immunohistochemical study revealed that SCN were negative for thyroglobulin and calcitonin but positive for carcinoembryonic antigen. Thirteen of 21 cases showed positive immunostaining with cytokeratin. Scattered calcitonin-positive cells were noted around the SCN. It is suggested from these findings that SCN of the thyroid are closely related to certain cells of ultimobranchial body vestiges which may be not of neuroectodermal origin but of endodermal origin.

Adult↗
PubMed1991

Interferon therapy for non-A, non-B chronic hepatitis.

We report the results of our study on 8-week consecutive interferon (IFN) treatment for chronic non-A, non-B hepatitis. In the 6 MIU/day group, most cases had continuously normalized alanine-aminotransferase (ALT) levels even after IFN treatment was discontinued. In responders whose ALT levels remained normal, not only the degree of inflammation, as seen from HAI scores, but also liver histopathological features were improved. Moreover, antibody to hepatitis C virus (anti-HCV) titer in responders was continuously decreased. Antiviral effects of IFN were observed by detection of HCV-RNA using the PCR technique. HCV-RNA became negative with IFN treatment, however, in some patients who relapsed after discontinuation of IFN treatment, re-elevation of ALT levels was usually preceded by re-appearance of HCV-RNA.

Alanine Transaminase↗
PubMed1991

Spontaneous oscillatory contraction (SPOC) of sarcomeres in skeletal muscle.

Skeletal myofibrils spontaneously oscillate under a condition where ATP, ADP, and Pi coexist and the concentration of free Ca2+ is less than about 1 microM. Although this oscillation phenomenon called SPOC is apparently simple, the molecular mechanism seems to be complex. The SPOC condition and the space-time pattern of SPOC wave suggest that the dynamics of association and dissociation of Pi (ADP) is regulated by the mechanical strain imposed on actin and myosin; the enzymatic activity (ATPase) of actomyosin complex and the mechanical event (contraction) are thus coupled to each other. In this sense, the nature of the mechanochemical enzyme, actomyosin ATPase, is revealed in SPOC.

Adenosine Diphosphate↗
PubMed1991

Comparative effects of diet or glibenclamide on insulin secretion and action in non-obese NIDDM.

We compared the effects of dietary treatment (D) and diet plus glibenclamide (DPG), for 3 weeks, on glycemia, insulin secretion and action in 2 groups of non-obese patients with NIDDM matched for fasting plasma glucose level. Fasting glycemia decreased in both groups with greater reductions after DPG (n = 7, 10.0 +/- 0.6 to 6.3 + 0.3 mmol/l, M +/- SEM, P less than 0.02) than after D (n = 7, 10.1 +/- 0.8 to 8.7 +/- 0.7 mmol/l, M +/- SEM, P less than 0.02). The magnitude of day-time elevation of plasma glucose over the fasting level, however, was reduced only after DPG. DPG but not D improved the plasma insulin response to glucose ingestion and in vivo insulin action measured by insulin tolerance test with unaltered erythrocyte 125I-insulin binding. This might indicate potentiation of insulin action at post-receptor binding steps. Improvements in in vivo insulin action and in insulin secretion after DPG closely correlated with decrease in fasting glycemia and reduction in the day-time elevation of plasma glucose levels, respectively. In conclusion, diet improved glycemic control in non-obese patients with NIDDM mainly by reducing fasting glycemia, although the mechanism remains unknown. Glibenclamide added to the diet further decreased fasting glycemia by improving in vivo insulin action and reduced the magnitude of day-time elevation of plasma glucose by enhancing endogenous insulin secretion.

Blood Glucose↗
PubMed1991

A placenta-specific 5' non-coding exon of human prolactin.

Expression of human prolactin (hPRL) is restricted to the anterior pituitary and the placenta, strictly, the decidualized endometrium of the uterus. We have cloned and sequenced placental hPRL cDNAs and also the 5' part of the hPRL gene, and found that the placental mRNA consisted of six exons including a 5' non-coding exon which was not present in the pituitary mRNA known to consist of five exons. The placenta-specific exon, designated exon 0, was located 5.3 kb upstream of the first exon of the pituitary mRNA. We have also located the transcriptional start site of the hPRL gene in the placenta to be 21 bp upstream from the 5' end of the longest cDNA clone we obtained using mRNA from human placenta of 22 weeks of gestation. These results suggest that the hPRL gene contains a placenta-specific promoter other than the pituitary-specific promoter.

Amino Acid Sequence↗
PubMed1991

19-hydroxyandrostenedione does not modulate [3H]aldosterone binding to human mononuclear leucocytes and rat renal cytosol.

To verify the aldosterone amplifying action of 19-hydroxyandrostenedione (19-OH-AD), we investigated [3H]aldosterone and [3H]19-OH-AD binding to type I (mineralocorticoid) receptor in the renal cytosol of adrenalectomized and ovariectomized rat, and human mononuclear leucocytes (MNL). In the [3H]aldosterone binding study, the cytosol was incubated with [3H]aldosterone and 200-fold RU28362 (11 beta,17 beta-dihydroxy-6-methyl,17 alpha-(1-propynyl)-androsta-1,4,6- trien-3-one), a pure glucocorticoid, with or without 19-OH-AD. Scatchard plots of [3H]aldosterone binding to cytosol with 0.2 or 20 nM 19-OH-AD or without 19-OH-AD were linear. Dissociation constants (Kd) and maximum bindings (Bmax) without 19-OH-AD, and with 0.2 and 20 nM 19-OH-AD were: 0.71 +/- 0.03 nM and 23.0 +/- 3.4 fmol/mg protein (mean +/- SD, n = 3), 0.72 +/- 0.05 nM and 23.1 +/- 2.3 fmol/mg protein (n = 3), and 0.77 +/- 0.04 nM and 22.9 +/- 4.8 fmol/mg protein (n = 3), respectively. 19-OH-AD did not significantly change the Kd and Bmax of [3H]aldosterone binding. A high concentration of 19-OH-AD slightly displaced 0.2 or 5 nM [3H]aldosterone bound to cytosol. In human MNL, Scatchard plots of [3H]aldosterone binding with both 0.2 and 20 nM 19-OH-AD and without 19-OH-AD were linear. Kd and Bmax were, respectively, 1.00 nM and 780 sites/cell in the absence of 19-OH-AD, and 1.07 nM and 774 sites/cell in the presence of 0.2 nM 19-OH-AD. Without 19-OH-AD they were, respectively, 0.95 nM and 551 sites/cell, and 1.10 nM and 560 sites/cell with 20 nM 19-OH-AD. A high concentration of 19-OH-AD slightly displaced 0.2 or 5 nM of [3H]aldosterone bound to MNL. In both tissues, there was no obvious specific binding of [3H]19-OH-AD within the range of 1-60 nM. The above results suggest that the amplifying effect of 19-OH-AD on aldosterone mineralocorticoid action may not occur at the binding site of aldosterone to type I receptor, and that 19-OH-AD itself may not have any direct or indirect mineralocorticoid actions on the steroid receptor-mediated process in the rat kidney and human MNL.

Adrenalectomy↗
PubMed1991

Endoscopic re-establishment of membranous urethral disruption.

A total of 17 patients with traumatic membranous urethral disruption underwent urethral reconstruction via a core-through technique. Followup was 1 to 8 years (mean 3.7 years) postoperatively, and included 6 weeks with an indwelling catheter, periodic dilation for 6 months and occasional sounding. Within 1 year postoperatively, 6 patients required additional scar incision, including 3 who underwent scar resection. At 1 to 8 years postoperatively 6 patients had complications: 3 had stricture requiring periodic dilation (including 2 who underwent scar incision), while 2 had mild stress incontinence and 1 had nocturnal enuresis. Traumatic impotence was noted in 7 patients but the operation was not the cause in any. This method of endoscopic management was found to be an acceptable alternative to urethroplasty in cases of membranous urethral disruption.

Adult↗
PubMed1991

Skin irritation induced by topically applied timolol.

1. Erythema induced by topically applied timolol, a non-selective beta-adrenoceptor blocker, was assessed in six male volunteers. Intensity of erythema developed on the inner surface of the left forearm where timolol free base was applied for 10 h was measured by a visual score, laser doppler flowmeter and reflectance spectrophotometry. Plasma timolol concentrations collected from the left and right arms were also measured. 2. The mean values for blood volume and blood flow per unit volume of tissue both of which were assessed by a laser doppler flowmeter, haemoglobin index measured by reflectance spectrophotometry, and magnitude of erythema graded by a visual score significantly increased after the application of an acrylic co-polymer adhesive patch containing 20% (w/v) timolol free base. 3. Plasma timolol concentrations collected from the left antecubital vein were 2.4 to 10.7 times greater than those from the right arm and had significant correlations (rs = 0.55 to 0.76) with the parameters indicating the extent of erythema developed where a patch containing timolol was applied. 4. The inter-individual variation of timolol was attributed to that of the diffusivity of timolol through skin rather than that of the skin reactivity to topically applied timolol because the plasma timolol concentrations drawn from the left arm in the subjects who did not develop erythema were very low.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1991

Distribution and immunochemical specificities of fimbriae of Porphyromonas gingivalis and related bacterial species.

Rabbit polyclonal antibody (Poly-1) and mouse monoclonal antibodies (mAbs) TO-11, TO-14 and TO-M1 specific for Porphyromonas gingivalis 381 fimbriae were prepared. Poly-1 and the 3 mAbs were screened for their reactivity with whole cells oral and nonoral black-pigmented bacterial species by enzyme-linked immunosorbent assay (ELISA) and the binding experiment using [125I]Poly-1 and [125I]mAbs. ELISA revealed that Poly-1 definitely reacted with whole cells of all the 11 strains of P. gingivalis tested. However, 8 of 11 P. gingivalis strains reacted with mAbs TO-11, TO-14 and TO-M1. These results were confirmed by the specific binding of radiolabelled Poly-1 and mAb TO-11 to the 8 strains. The M(r) of the fimbrial subunit protein (fimbrilin) isolated and purified from P. gingivalis strains 381, BH18/10, HW24D-1, 6/26 and OMZ 314 was 41 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis. It was found by immunoblotting that mAbs TO-11 and TO-14/TO-M1 recognized different epitopes of fimbrial protein from P. gingivalis strains. Immunoelectron micrographs of whole cells and the purified fimbriae of P. gingivalis strains visualized similar serotype-specific antibody bindings to the fimbriae. These results indicate that 11 strains of P. gingivalis could be divided into at least 2 separate groups based on the immunochemical specificities of the fimbriae.

Animals↗