Search PubMed⌕ Search

Biomedical subjects

K Higuchi

Publications and source records attributed to K Higuchi.

At least 325 records · Page 18Linked to original sources

In vitro adaptive cytoprotection in gastric cells isolated from rat stomach.

The effects of mild irritants (2-5% ethanol or water at 45-55 degrees C) on production of prostaglandins (PGs) in gastric cells isolated from rat stomach and the damage caused by 15% ethanol were assessed. Gastric cells were isolated by the method of Matuoka et al., by which a suspension rich in surface epithelial cells was obtained. Synthesis of PGE2 by the cells was stimulated by 3% ethanol or water at 50 degrees C. The damage caused by 15% ethanol was much less in the cells treated with 3% ethanol or 50 degrees C water beforehand than in untreated cells. This protective effect by 3% ethanol or 50 degrees C water was abolished when the cells were treated with 10(-4) M indomethacin. These results suggest that 3% ethanol or 50 degrees C water protects the gastric cells from damage caused by 15% ethanol, possibly via endogenous PGs.

Animals↗

Extracellular collagenase, proteoglycanase and products of their activity, released in organ culture by intact dermal inflammatory lesions produced by sulfur mustard.

Peak (1 and 2 d) and healing (3, 6, and 10 d) inflammatory lesions were produced in rabbits by the topical application of the military vesicant, bis(2-chloroethyl)sulfide, commonly called sulfur mustard (SM). SM produces an acute sterile dermal inflammatory reaction with little or no necrosis, except in the epidermis, which dies during the first day. After an animal was killed, its lesions were excised intact, as full-thickness 1.0-cm2 explants. They were then organ-cultured for 3 d in order to maintain the viability of both local and infiltrating cells. The extracellular fluid in each lesion equilibrated with the culture fluid, which was collected daily and analyzed for collagenase and proteoglycanase activities. These metalloproteinase activities were measured after we had i) destroyed the alpha-macroglobulin inhibitors with KSCN, ii) destroyed the tissue inhibitor of metalloproteinases (TIMP) by reduction and alkylation, and iii) activated the latent proteinase activity with aminophenylmercuric acetate (APMA). Hydroxyproline-containing peptides and glycosaminoglycans (GAG) released into the culture fluids were also measured as indicators of local collagenase and proteoglycanase activity within the inflammatory lesions. In general, the levels of both the metalloproteinases and the products of their activity were higher in second- and third-day culture fluids than in first-day culture fluids, and higher in fluids from SM lesions than in those from normal skin. The activated fibroblast was apparently the major cell type producing the collagenase and proteoglycanase. The hydrolysis of collagen and ground substance occurs pericellularly. An excess of inhibitors exists outside the pericellular region. The daily change in culture fluids apparently decreased such inhibitors, so that by the second and third day of culture we could detect the changes in pericellular enzyme activity that were not detectable on the first day of culture. As the inflammatory lesions healed, the extracellular enzyme products (hydroxyproline and GAG) increased more than the enzymes that produced these products. With healing, a decrease occurs in the extravasation of all serum components, especially the large ones such as the alpha-macroglobulin inhibitors. We propose that during healing, the decrease in these inhibitors allows the metalloproteinases to begin the remodeling process, and that during the peak phase of inflammation, these same inhibitors protect extracellular matrix against hydrolysis by such proteinases.

Animals↗

Immunohistochemical distribution of CA19-9 in normal and tumor tissues of the kidney.

The immunohistochemical distribution of CA19-9 in normal and tumor tissue of the kidney was investigated. CA19-9 was detected in the cytoplasm and apical surface of renal proximal tubules, distal tubules and uroepithelium of the renal pelvis. Eight of 28 renal cell carcinomas (29%) expressed CA19-9. CA19-9 was also detected in 2 cases of transitional cell carcinoma and 1 of 4 cases of Wilm's tumor, but not in angiomyolipoma. As the measurement of CA19-9 is widely used to detect gastrointestinal carcinoma, the expression of CA19-9 in normal and neoplastic kidney tissue might have some clinical significance.

Antigens, Tumor-Associated, Carbohydrate↗

Corticotropin-releasing hormone- and adrenocorticotropin-producing pituitary carcinoma with metastases to the liver and lung in a patient with Cushing's disease.

A 53-yr-old man with Cushing's disease was found to have a pituitary carcinoma with metastases to the liver and lung which produced both CRH and ACTH simultaneously. Despite removal of the pituitary tumor, his Cushing's disease worsened. Endocrinological examination then demonstrated elevated plasma CRH and markedly elevated plasma ACTH, beta-lipotropin, and cortisol concentrations, increased urinary 17-hydroxycorticosteroid and 17-ketosteroid excretion, and no suppression of serum cortisol after low or high dose dexamethasone administration. Urinary 17-hydroxycorticosteroid excretion increased in response to metyrapone, and lysine vasopressin elicited a striking increase in plasma ACTH. A computed tomographic scan of abdomen revealed multiple hypodense areas in the liver and bilateral adrenal hyperplasia. Postmortem histological examination revealed a necrotic hemorrhagic pituitary carcinoma with metastases to the liver, lung, and olfactory bulb. Immunohistochemical staining, gel filtration, and Northern blot analysis of liver and lung metastases revealed evidence of the production of both CRH and ACTH in these metastases. We concluded that the patient's pituitary carcinoma produced both CRH and ACTH.

Adrenocorticotropic Hormone↗

Immunohistochemical examination of Peyer's patches in senescence-accelerated mice.

The distribution of T cells, B cells and murine senile amyloid protein in Peyer's Patches was examined in senescence accelerated (SAM-P/1) and control (SAM-R/1) mice ranging in age from two to ten months. An immunohistochemical detection of lymphocyte surface antigens of T cells and B cells. A murine senile amyloid protein in Peyer's patches was detected by immunohistochemical staining with the specific antiserum. Congo red staining and electron microscopy. The T cell population increased and B cell population decreased slightly with age in SAM-P/1 mice, but little change was observed with age in SAM-R/1 mice. Murine senile amyloid protein positive spots were seen surrounding the vessels of the thymus-dependent area at 6 months of age, and were observed throughout the Peyer's patches at 10 months of age, but were not observed by 10 months of age in SAM-R/1 mice.

Aging↗

Applicability of osseointegrated oral implants in the rehabilitation of partial edentulism: a prospective multicenter study on 558 fixtures.

Nine clinical centers using the Brånemark System participated in a prospective study of 159 partially edentulous patients between 18 and 70 years of age. Clinical parameters evaluated were plaque index, gingivitis, pocket depth, bleeding index, tooth mobility, and stomatognathic function. Initially, 558 fixtures were placed and 521 remained in the study following prosthesis placement (199 prostheses in 154 patients). Fixtures were lost or unaccounted for because of nonintegration prior to prosthesis fabrication (19), patient withdrawal (11), prosthodontic reasons (6), and failure during prosthetic procedures (1). Failure was primarily attributable to unfavorable bone quality, sex (more in males), and smaller fixture size. Complications and failure related to other patient characteristics are presented. After 1 year of a 5-year study, preliminary results suggest that a success rate equal to or better than that obtained with edentulous patients may be expected.

Adult↗

Meniscectomy operation as a surgical treatment for internal derangement of the temporomandibular joint in our department.

This paper describes the surgical treatment of six patients with internal derangement of the temporomandibular joint (nine joints). Meniscectomy was performed on all the patients, because severely advanced cases in which the articular disk could not be preserved or replaced were chosen. Our surgical technique and the results of short-term follow up are presented. Indications of meniscectomy and the criteria for postoperative evaluation are also described. The postoperative outcomes were assessed as "good" for seven joints in five patients and as "acceptable" for two joints in one patient.

Aged↗

[Effect of a spacer device used with metered dose inhaler].

Metered dose inhaler (MDI) is widely used in treatment of bronchial asthma. But adequate efficacy is not obtained if the patients use an improper technique of inhalation. The spacer device was designed to reduce such inhalation errors. Three types of spacers (pear type, tube type, paper spacer) were studied to confirm their usefulness in bronchial asthma. Bronchodilating effect of procaterol (10 micrograms/puff X 2) in conventional MDI or MDI with a spacer was evaluated. There were no significant difference in the effect on the pulmonary function after single inhalation of MDI with or without a spacer for 60 minutes. In regular use of MDI with a spacer for two weeks, PEFR and FEV1.0 were slightly improved. These results suggest that effect of MDI with a spacer may be more effective than MDI alone in regular use.

Administration, Inhalation↗

Rotation-advancement flap method for correction of partial anomalous pulmonary venous drainage into the superior vena cava.

Three patients with partial anomalous pulmonary venous drainage into the superior vena cava underwent repair by a rotation-advancement flap method. The technique consisted of atrial partitioning, enlargement of the superior vena cava, and protection of sinus node function. Follow-up studies of all patients were done between 12 and 15 months after the operation. The superior vena cava was not stenosed and its diameter was normal, as demonstrated by cavograms. Pulmonary venous return appeared normal on angiograms, and sinus node function was normal by electrophysiologic studies.

Adult↗

[Repair of pure mitral insufficiency--experience in 50 patients].

Between February 1982 and March 1987, 50 adults underwent mitral valve repair for pure mitral insufficiency representing 54% of all adults having mitral valve surgery for pure mitral insufficiency. Ages ranged from 20 to 73 years (50.0 +/- 11.6). Anterior leaflet prolapse was present in 11, posterior leaflet prolapse in 26 and annulus dilation in 13. The mitral valve was repaired by quadrangular resection in 21, triangular resection in 2, plication without resection in 4, chordal shortening in 8 and annuloplasty alone in 15. Commissural annuloplasty was performed in addition to leaflet repair or chordal shortening in other 14 patients. The competence of the mitral valve was usually evaluated under beating conditions. 79% of the attempted repairs was considered successful in the posterior leaflet, contrasting to only 37% in the anterior leaflet. Prolapse of the anterior leaflet remains a surgical challenge. There were two early deaths (4%). During the follow up period (Mean 1.9 years, range 0.2-5.2 years), 2 late deaths (4%) were observed, one of them from thromboembolism, before adopting the policy of routinely anti-coagulating these patients during the first few months. 4 patients (9%), early in our experience, required reoperation within 4 months of surgery: two for severe mitral insufficiency and two for severe mechanical hemolysis. At reoperation, residual insufficiency was present in one, valve suture tear due to technical imperfection in two and complete disruption of the valve tissue at the suture line in one. Four additional patients had transient mechanical hemolysis requiring no specific therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Fluorometric examination of tissue amyloid fibrils in murine senile amyloidosis: use of the fluorescent indicator, thioflavine T.

Thioflavine T, a fluorescent indicator of amyloid fibrils (Naiki H, Higuchi K, Hosokawa M, Takeda T: Anal Biochem 177:244, 1989), has been tested in unfractionated tissue homogenates. With 250 nM thioflavine T, liver homogenates from a 17-month-old SAM-P/1 (senescence accelerated mouse-prone), which contained amyloid fibrils in murine senile amyloidosis (fASSAM) fluoresced brightly, whereas normal liver homogenates showed a negligible fluorescence. The following evidence confirmed that the fluorescence in the unfractionated preparations specifically represented fASSAM. The fluorescence of fASSAM deposited liver tissue was diminished to the level of the normal liver when the structure of the amyloid fibrils was disrupted by guanidine-HCl. Second, about 90% of the fluorescence of fASSAM deposited liver tissue was fractionated in the water-soluble fraction, in which amyloid fibrils are generally enriched. We then determined the concentration of fASSAM in the tissue, from the fluorescence and using the standard curve described in the above mentioned report. Lower limits of fASSAM determination were about 1 microgram/mg of tissue. A marked regional heterogeneity of fASSAM deposition was observed in the liver. We observed a linear correlation between fASSAM concentration and percentage of amyloid positive area in the liver. Age-dependent increases in fASSAM concentrations and total fASSAM contents were noted in the liver and spleen of 11 to 15-month-old SAM-P/1. There was also a positive correlation between the organ weight and fASSAM concentrations in both organs. Thus, thioflavine T is of practical use for the determination of fASSAM concentrations in the tissue.

Aging↗

Structural organization of the gene encoding apolipoprotein A-II in an amyloidotic strain of senescence-accelerated mouse.

An inherited polymorphism occurring in the murine apolipoprotein A-II (ApoA-II) transcript seems to be related to the senile amyloidosis which occurs in accelerated-senescence-prone mice (SAM-P). Such being the case, we have determined the entire nucleotide (nt) sequence of the apoA-II gene. The length of the gene is about 1.3 kb and it is interrupted by three introns and the four exons aligned perfectly with the previously sequenced elements of an apoA-II cDNA. Two-nt substitutions [Pro-5(CCA)----Gln(CAG)] in the SAM-P genome were identified in the third exon, hence, we could use a restriction fragment length polymorphism to detect the apoA-II molecular type. Several possible regulatory signals were identified (i) in the 5'-flanking region, including CAAT and TATA boxes, the viral enhancer-like sequence, and the consensus sequences of estrogen response element, and (ii) in the 3'-flanking region, including sequences conserved in the immunoglobulin enhancer, glucocorticoid and estrogen response elements, and a B1 repetitive sequence.

Amino Acid Sequence↗

Homozygous hypobetalipoproteinemia: transcriptional regulation and 5'-flanking sequence analysis in an apolipoprotein B deficiency state.

Apolipoprotein (apo) B is the principal apolipoprotein of chylomicrons, very-low-density lipoproteins (VLDL) and low-density lipoproteins (LDL). Patients with homozygous hypobetalipoproteinemia (HBL), characterized by apoB deficiency, have markedly decreased levels of hepatocyte mRNA as well as intracellular B apolipoprotein, and a virtual absence of plasma apoB. We have cloned, sequenced and analyzed the 5' regulatory region of the human apoB gene from -899 to +121 bp in normal and hypobetalipoproteinemic subjects. TATA and CAAT boxes were located at -30 and -61, respectively, and two GC-like boxes were identified at positions +56 and +108. The analysis of the HBL sequence revealed two substitutions at positions -838 and -517, when compared to the normal sequence. These substitutions were not present in any known apoB regulatory elements. The transcriptional activities of the homozygous hypobetalipoproteinemic and normal regulatory regions were compared by chloramphenicol acetyltransferase (CAT) assays in Hep G2 cells, and were found to be the same. Therefore, we conclude that the 5' regulatory region of the HBL apoB gene in this kindred is normal, and the two base substitutions do not affect promoter activity of the apoB gene. These studies suggest that a coding region abnormality in the apoB gene may lead to HBL.

Apolipoproteins B↗

[Effect of remission induction chemotherapy on blood coagulability in patients with gynecological malignancies].

In 12 patients (38 courses) with gynecological malignancies who had been treated with remission induction chemotherapy, we measured the levels of ESR, Platelet, PT, APTT, Hepa T, AT III, alpha 2 PI, FDP and D-dimer, and we also measured such molecular markers as Fibrinopeptide A (FPA), Fibrinopeptide B beta 1-42 (FPB beta 1-42), and Fibrinopeptide B beta 15-42 (FPB beta 15-42) before and after chemotherapy. Then the relation between the post chemotherapeutic trends and prognosis for patient with gynecological malignancies were investigated. 1) Before chemotherapy, the levels of ESR, FDP, D-dimer and FPB beta 1-42 were increased, PT and APTT were shortened significantly in cases on groups IIIrd and IVth stage compared with in cases on groups Ist and IInd stage (p less than 0.05). The levels of FPA were also high, but there was no significant differences. The levels of FPB beta 15-42 were almost same in both groups. However, the each markers indicated the existence of chronic DIC in cases of group IIIrd and IVth stage. 2) One week after chemotherapy, the levels of ESR, fibrinogen, FDP and FPA were decreased, while FPB beta 1-42 and FPB beta 15-42 were increased, suggesting elevated fibrinolytic activity. Two weeks after chemotherapy, there was stronger tendency to coagulation dominant again, but it was only temporary. Three weeks after chemotherapy, the hemostatic balance was regained. 3) In patient with complete remission after effective chemotherapy, their coagulability data were showed within normal range, however, some cases with poor prognosis were not able to obtain the recovery of hemostatic balance, and the levels of molecular markers were significantly elevated. Coagulative activity was more enhanced than fibrinolytic activity in patients with progressive gynecological malignancies, but hemostatic balance was maintained clinically. The hemostatic balance was disrupted by the chemotherapy, but this balance was regained for the IIIrd week. Accordingly, the recovery of hemostatic balance with effective chemotherapy is related to the prognosis for patients with gynecological malignancies, and the levels of molecular markers may be able to expect the prognosis for patients.

Adult↗

Treatment of hepatocellular carcinoma utilizing lymphokine-activated killer cells and interleukin-2.

This paper is a report on adoptive immunotherapy involving consecutive injections of recombinant interleukin-2 and lymphokine-activated killer (LAK) cells in the treatment of hepatocellular carcinoma. Peripheral blood lymphocytes, obtained by leukopheresis, acted as the activated killer cells with a co culture of recombinant interleukin-2 in the culture system. After 4 days, the activated killer cells were returned into the patients' bodies intra-arterially and intravenously. No complete remissions or partial remissions have resulted, although five of the seven patients showed a significant decrease in their serum alpha-fetoprotein levels after treatment. In addition, one case showed a patent portal truncus while another indicate the appearance of central necrosis on the computerized tomograph scan. Although the period of observation was short, there were no recurrences after the combination therapy of tumor resection and LAK adoptive immunotherapy. It might be difficult to treat hepatocellular carcinoma with adoptive immunotherapy alone, but there is some possibility of conducting therapy for hepatocellular carcinoma after removing the majority of the tumor cells by surgical resection and transcatheter arterial embolization therapy. This conclusion indicates, at least theoretically, that adoptive immunotherapy will be suitable in the treatment of hepatocellular carcinoma as one of the combination therapies with the two major forms of treatment mentioned above.

Adult↗