Search PubMed⌕ Search

Biomedical subjects

K Kudo

Publications and source records attributed to K Kudo.

At least 271 records · Page 15Linked to original sources

Clinical application of dental implant with root of coated bioglass: short-term results.

During the last 4 years 73 dental implants with root-coated bioglass to replace one to three teeth in the premolar and molar sites of the mandible were inserted. The bonding ratio between implant and bone was observed clinically 1 year after implantation and installation of the superior structure. This ratio measured 52.4% to 63.3%. An acoustoelectric tester was developed that advanced our skills. The emphasis was placed on a tight fit between implant and surrounding bone.

Adolescent↗

Methamphetamine and amphetamine concentrations in postmortem rabbit tissues.

The feasibility of detecting methamphetamine and its major metabolite, amphetamine, in postmortem tissues over a 2-year period was examined. It is important to determine if the abuse and toxic effects of drugs can be proved from evidence found in decayed, submerged, or stained tissue materials. The blood, urine, liver, skeletal muscle, skin and extremity bones from rabbits given methamphetamine intravenously were kept at room temperature, under 4 different conditions: sealed in a test tube, dried in the open air, submerged in tap water and stained on gauze. Methamphetamine was present in all the samples, with slight change in concentration in case of sealed and air dried tissues. Changes varied in bones kept in water. There were considerable decreases in methamphetamine in blood and urine stains. Despite long term storage, drug abuse and/or toxicity could be determined, in all tissues examined.

Amphetamine↗

Presence of four tachykinins in an acid extract of the carp intestinal bulb (Cyprinus carpio).

1. The pharmacological and chemical properties of substance P-like peptides isolated from an acid extract of the carp intestinal bulb were examined using guinea-pig ileum longitudinal smooth muscle. 2. On a Sephadex G25 column (3 x 96 cm), smooth muscle contracting material was eluted as two peaks (fraction-1 and fraction-2). The molecular weight of the fraction-1 was estimated to be 2300 and that of the fraction-2 to be 1530. 3. The pharmacological properties of the contracting materials in fraction-1 and fraction-2 resembled those of substance P and neurokinin A. 4. The susceptibility of the contracting activity of fraction-1 to proteolytic enzymes resembled that of physalaemin but, on the other hand, the susceptibility of that of fraction-2 resembled those of eledoisin and neurokinin A. 5. Ion-exchange chromatography on sulfopropyl-Sephadex C25 indicated the presence of one contracting material in fraction-1 and three contracting materials in fraction-2. The elution positions of four materials were different from that of substance P. 6. These results indicate that four tachykinins different from substance P are present in an acid extract of the carp intestinal bulb.

Amino Acid Sequence↗

Chronic effects of synthetic endothelin on blood pressure and sodium excretion in rats.

Continuous infusion of endothelin at a rate of 60 micrograms/kg/day into the jugular vein of rats via osmotic minipumps induced a significant increase in systolic blood pressure, but did not induce any significant changes in urine volume and urinary sodium excretion, compared to those in vehicle-infused rats. When 6 mg/kg/day of benidipine, a newly developed calcium channel blocker, was administered simultaneously with 60 micrograms/kg/day of endothelin, the systolic blood pressure of conscious rats rose on Day 1 to only 137.0 +/- 2.4 mm Hg (P less than .05) compared to the rise to 163.8 +/- 4.7 mm Hg when endothelin alone was infused. The antihypertensive effect of benidipine was sustained. The present results suggest that endothelin can act as a circulating hormone. In addition, they clearly demonstrate that the calcium channel blocker attenuates the elevation of blood pressure induced by endothelin.

Animals↗

Calcium channel blockers reverse the sustained elevation of blood pressure induced by chronic infusion of endothelin in conscious rats.

To determine whether endothelin could act as a circulating hormone in the regulation of blood pressure and sodium-water excretion, we assessed the chronic effects of synthetic endothelin on systolic blood pressure, urine volume and urinary sodium excretion in conscious rats, and also evaluated the effects of benidipine or nilvadipine, newly developed calcium channel blockers, in rats infused chronically with synthetic endothelin. Continuous infusion of endothelin at a rate of 60 micrograms/kg/day into the jugular vein via osmotic minipumps induced a significant increase in systolic blood pressure, but did not induce any significant changes in urine volume and urinary sodium excretion, compared to those in vehicle-infused rats. On the contrary, the infusion of endothelin at a rate of 6 micrograms/kg/day did not induce any significant changes in systolic blood pressure, urine volume and urinary sodium excretion, compared to those in vehicle-infused rats. When 6 mg/kg/day of benidipine or 10 mg/kg/day of nilvadipine was administered simultaneously with 60 micrograms/kg/day of endothelin, the systolic blood pressure rose on Day I to only 137.0 +/- 2.4 mmHg (p less than 0.05) and 119.7 +/- 5.9 mmHg (p less than 0.05) compared to the rise to 163.8 +/- 4.7 mmHg when endothelin alone was infused. The antihypertensive effect of benidipine or nilvadipine was sustained for the entire experimental period and was not associated with any significant changes in urine volume and urinary sodium excretion. The present results suggest that endothelin can act as a circulating hormone and might be involved in the regulation of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Experimental hypersensitivity pneumonitis and enhancement of granuloma formation by low dose irradiation with increased interleukin-1 activity of granuloma in genetically low responder mouse (C3H)].

Possible enhancing effects by low dose total body irradiation on pulmonary granuloma formation induced by intratracheal injection of ovalbumin-coupled beads in low responder C3H mouse were studied. The low dose (3.5 Gy) irradiation increased the size of granuloma in low responder C3H mouse as large as the granuloma formed in high responder C57BL/10 mouse. The resolution of granuloma which usually disappeared within 9 days was also prolonged by the irradiation. Increase in IL-1 activity of lung extracts but not IL-2 activity was parallel to the enhancement of granuloma formation and/or the delayed resolution of granuloma. These results indicated that the radiation-sensitive cells might regulate IL-1 producing cell, possibly macrophages which made pulmonary granuloma.

Alveolitis, Extrinsic Allergic↗

Demonstration of ingested thinner.

Taking a practical forensic case that provided an opportunity, an attempt was made to prove that paint thinner had been ingested by the victim. One ml of standard thinner solution, which was prepared by mixing toluene, ethyl acetate, and isobutanol, was given by gavage to rats, after which, on sacrifice of the animals, the distribution of thinner components in the body tissue and in the gastric contents was examined by gas chromatography, using the salting-out technique and the headspace method. Three thinner components and ethanol, a metabolite of ethyl acetate, were found to be present in the gastric contents, whereas only toluene was found in the blood and in the other tissue. From these results we thus have concluded that paint thinner taken can be proved by detecting the presence of ethyl acetate and isobutanol together with toluene in the stomach, whereas only toluene can be detected in the body fluids and the other tissue.

Acetates↗

[The possible involvement of immune complexes in pulmonary granuloma formation in experimental hypersensitivity pneumonitis].

Hypersensitivity pneumonitis (HP) is a disease caused by inhaled organic dust. The alveolitis and granuloma are characteristic features of HP. The precise mechanism of granuloma formation is still unclear. The roles of immune complexes and primed T cell in relation to granuloma formation were studied. Local lymph node cells were obtained from C57BL/6 mice immunized by injection of ovalbumin (OA) or keyhole limpet haemocyanin (KLH) emulsified in complete Freund's adjuvant into footpads. Thereafter enriched T cells were obtained by passage through nylon wool columns. Antigens (OA, KLH) were chemically coupled to Sepharose 4B beads (OA-beads, KLH-beads). The immune complex was made by the incubation of the antigen-coupled beads and the immunized mouse serum at 37 degrees C for 2 hours. The recipient mouse irradiated by 6.5 Gy was transferred with 3 X 10(7) T cells and challenged with intratracheal instillation of 1 X 10(4) antigen-coupled beads or 1 X 10(4) immune complex-coupled beads. The recipient mice were sacrificed day 3 after cell transfer and challenge. The radius of pulmonary granuloma was measured by microscopic examination of the HE-stained section. The radius of granuloma increased in the recipient mouse which received the primed T cell and was challenged with immune complex-coupled beads compared with any other combination of cell transfer and antigen challenge. This result suggests that not only T cell but also immune complexes play an important role in granuloma formation in HP.

Alveolitis, Extrinsic Allergic↗

[A case of sarcoidosis demonstrating spontaneous production of interleukin-1 alpha and beta by alveolar macrophage].

A 44-year-old man was admitted for evaluation of dyspnea on exertion and subcutaneous nodules. The chest X-ray on admission revealed bilateral hilar lymph node swelling and diffuse micronodular shadows throughout both lung fields. Ga scintigram demonstrated diffuse abnormal uptake. Serum angiotensin converting enzyme was elevated significantly (86.6 IU/I). The TBLB specimen confirmed the diagnosis of sarcoidosis. The cell numbers in bronchoalveolar lavage fluid was increased (4.4 x 10(8), the percentage of lymphocytes was elevated (64%) and the ratio of Leu 3a+/Leu 2a+ was very high (16.07). We further evaluated the spontaneous IL-1 release in vitro by alveolar macrophages obtained by bronchoalveolar lavage. The results showed that large amounts of IL-1 alpha and beta were produced spontaneously by alveolar macrophages before therapy, followed by a decrease in production after corticosteroid treatment. Previously, the authors reported that no significant amount of IL-1 alpha and beta was detected in 5 normal volunteers and 6 other active sarcoidosis cases which improved without therapy. Therefore, significant amounts of spontaneous release of IL-1 alpha and beta in vitro from alveolar macrophages in sarcoidosis might be considered as an index for the necessity of systemic corticosteroid treatment.

Adult↗

[Spontaneous production of interleukin-1 alpha and beta by alveolar cells from patients with sarcoidosis].

The spontaneous production of interleukin-1 alpha and beta by alveolar cells obtained by BAL from 7 active pulmonary sarcoidosis and 5 normal volunteers was evaluated. The activity of disease in one case was considered to be highly active because of the chest X-ray pattern (diffuse micronodular shadows), highly intense Ga up take in lungs, increased number of BAL cells and high level of S-ACE. The contents of IL-1 alpha and beta were measured by ELISA in the culture supernatants of alveolar cells after 24 hours culture without any stimulus. Large amounts of IL-1 alpha and beta production were found in highly active case. No significant amount of IL-1 alpha and beta, however, was detected in 6 other active sarcoidosis cases and 5 normal volunteers. Therefore, spontaneous release of IL-1 alpha and beta in vitro from alveolar cells in sarcoidosis might be considered as an index for the necessity of systemic corticosteroid treatment and its relationship to the spontaneous remission of sarcoidosis in Japanese patients was discussed.

Bronchoalveolar Lavage Fluid↗

Sulfide concentrations in postmortem mammalian tissues.

Postmortem changes in sulfide concentrations in body tissues were examined in autopsied rats exposed to hydrogen sulfide concentrations of 550 to 650 ppm, and in nonexposed rats and humans. Analyses were made by gas chromatography, following an extractive alkylation. Sulfide concentrations in the blood, liver, and kidneys of rats increased in both the exposed and nonexposed groups, depending on the lapse of time after death. On the other hand, the lung, brain, and muscle showed little or no change in sulfide concentration with elapse of time after death. The data obtained from human tissues were almost the same as those for rats, except data for blood, in which no or little increase of sulfide was observed.

Animals↗

PGE2 synthesis in cultured renal papillary collecting tubule cells from young and aged spontaneously hypertensive rats.

To investigate whether altered renal medullary prostaglandin (PG) synthesis is involved in the development of hypertension in spontaneously hypertensive rats (SHR), we compared the capacity of PGE2 synthesis in cultured renal papillary collecting tubule cells from young (4-week-old) and aged (16-week-old) SHR and control Wistar-Kyoto rats (WKY). Basal levels of PGE2 synthesis were lower in young SHR cells than in WKY cells (p less than 0.001). Arachidonic acid-stimulated PGE2 synthesis, however, had a slight tendency to be higher in SHR cells than in WKY cells. Bradykinin- and A23187-stimulated PGE2 synthesis were similar in both strains. Basal levels of cyclic AMP were also lower in young SHR cells than in WKY cells (p less than 0.001), but the cAMP response to exogenous PGE2 was equal between the strains. In papillary collecting tubule cells from aged rats, basal levels of PGE2 and cyclic AMP as corrected for cellular protein were significantly lower than those in young rats, but there was no difference between the strains. Urinary excretion of PGE2 and thromboxane B2 was equal in aged SHR and WKY. These results suggest that papillary collecting tubule of young SHR and WKY may differ in the metabolism of PGE2 and cyclic AMP. This difference may be attributed to the possible defect in arachidonate availability in SHR.

1-Methyl-3-isobutylxanthine↗

Evidence for the in vivo production of interleukin-3 in lethally irradiated mice transplanted with syngeneic murine splenocytes.

We wish to demonstrate new evidence for the in vivo production of interleukin-3 (IL-3). Syngeneic murine splenocytes were transplanted into lethally irradiated mice. The spleen cells in these transplant mice spontaneously produced IL-3 in cultures, and IL-3-like activity was detected in the serum. Chronological changes of the Thy-1 antigen expression on the bone marrow cells, and the number of myeloid progenitors in the bone marrow from post-transplant mice correlated with the amount of IL-3 produced in vivo. These results suggest that IL-3 may be produced by activated T cells during the syngeneic mixed lymphocyte reaction induced in vivo.

Animals↗

Lipoprotein glomerulopathy: glomerular lipoprotein thrombi in a patient with hyperlipoproteinemia.

An unusual nephropathy presumably induced by abnormal lipid metabolism is described in a 57-year-old woman who presented with proteinuria and edema. Histology at renal biopsy was characterized by marked dilatation of capillary lumina. Sudan staining and electron microscopy demonstrated lipid droplets occupying the capillary lumina. The patient had no particular clinical symptoms of lipidosis, but hyperlipoproteinemia similar to type III was suggested by lipid profiles. The nephropathy is thought to be an inherited disorder because proteinuria was detected in her sisters and similar renal histology and lipid profile were observed in one of her sisters. This is believed to be the first detailed report of glomerular lipoprotein thrombi.

Adult↗

Rat aortic endothelium antagonizes nitroprusside-induced relaxation by release of the peptide endothelin.

1. The effects of porcine endothelin were examined in rat thoracic aortic rings. 2. Endothelin was a potent contractile agonist (EC50 4.0 +/- 0.6 nmol/L). 3. Endothelin (1 nmol/L) did not affect contractile responses to cumulative concentrations of the thromboxane analogue, U46619. 4. In the presence of U46619, but not phenylephrine, endothelin (1 nmol/L) and endothelium abrogated the vasodilator response to cumulative concentrations of sodium nitroprusside. 5. The inhibitory effect of endothelin on vasodilator responses to nitroprusside in the presence of U46619 was abolished by nifedipine (0.1 mumol/L) but unaffected by indomethacin (3 mumol/L) or haemoglobin (10 mumol/L). 6. These data suggest that endothelin generated by native endothelium exerts a physiological antagonism of sodium nitroprusside in the presence of thromboxane.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

Reduction of 7-ketolithocholic acid by human liver enzyme preparations in vitro.

The formation of chenodeoxycholic and ursodeoxycholic acids from 7-ketolithocholic acid by human liver preparations was examined in vitro. Liver preparations were incubated with 7-ketolithocholic acid at pH 5.5 in a sodium-potassium-phosphate buffer containing NADPH or NADH. The products formed were analyzed by gas chromatography and gas chromatography-mass spectrometry. Results showed that chenodeoxycholic and ursodeoxycholic acids could be formed from 7-ketolithocholic acid by human liver enzyme(s). The enzyme(s) required NADPH but not NADH as coenzyme and was localized largely in the microsomes. The conjugated 7-ketolithocholic acid, especially the taurine conjugated, was predominantly reduced to chenodeoxycholic acid, whereas the unconjugated 7-ketolithocholic acid was not reduced well to either chenodeoxycholic acid or ursodeoxycholic acid. Thus the reduction of 7-ketolithocholic acid by human liver enzyme(s) was found to be dependent on whether the substrate was conjugated or not.

Chenodeoxycholic Acid↗