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Biomedical subjects

N Katoh

Publications and source records attributed to N Katoh.

At least 19 recordsLinked to original sources
PubMed1998

The presence of two low molecular mass proteins immunologically related to 14 kilodalton serum amyloid A in the lipoprotein fraction and their decreased serum concentrations in calves with experimentally induced pneumonia.

A 14 kilodalton (kDa) serum amyloid A (apoSAA) protein was purified from cow serum. Rabbit antiserum to the 14 kDa apoSAA recognized, in addition to the 14 kDa protein, a 7.5-9.0 kDa protein and a protein having a molecular mass of less than 6.5 kDa (< 6.5 kDa protein). The possibility that the two proteins were contaminants was excluded by results showing that the two proteins detected in early stages of purification procedures were not found in the purified 14 kDa apoSAA fraction, as revealed by immunoblot analysis. As in the 14 kDa apoSAA, the 7.5-9.0 kDa protein was localized in the high-density lipoprotein fraction, while the < 6.5 kDa protein was in the low-density lipoprotein fraction. In calves with pneumonia induced by inoculation to the lungs of Pasteurella haemolitica, the serum concentration of the 14 kDa apoSAA was increased, whereas those of the 7.5-9.0 kDa and the < 6.5 kDa proteins were conversely decreased. The time-course study indicated that the increase in concentration of the 14 kDa apoSAA and decrease in that of the < 6.5 kDa protein occurred almost simultaneously. These results suggest that the 14 kDa apoSAA and the immunologically related 7.5-9.0 kDa and < 6.5 kDa proteins act as positive and negative acute phase reactants, respectively, and also that concentrations of the three proteins are regulated in concert in acute phase plasma.

Animals↗
PubMed1997

Isolation of viable egg cells of rape (Brassica napus L.).

The isolation of viable egg cells of rape (Brassica napus L.) has been achieved from microdissected ovules. The non-gametic cells of the embryo sac, synergids and central cells have also been isolated. Their morphology corresponded to that of these cells in situ, making a discrimination from isolated sporophytic cells possible. Two hours after isolation the egg cells were still viable. Viable egg cells have been reproducibly isolated with a frequency of 25% per dissected ovule.

Brassica↗
PubMed1997

Decreased serum lecithin:cholesterol acyltransferase activity in spontaneous cases of fatty liver in cows.

Lecithin:cholesterol acyltransferase (LCAT) activity in serum was evaluated in spontaneous cases of fatty liver in cows. The enzyme activity of 631 +/- 62 U (mean +/- SEM, decrease in nmol of free cholesterol per h per ml of serum) in cows with fatty liver (n = 16) was significantly (p < 0.01) lower than that in cows without fatty liver (979 +/- 22 U; n = 16). In addition to the decrease in LCAT activity, the concentrations of phosphatidylcholine (a fatty aryl donor for esterification of free cholesterol) and of cholesteryl esters (products of the LCAT reaction) were reduced in the high-density lipoprotein fractions from cows with fatty livers. The concentrations in the serum of apolipoprotein A-I, an activator of LCAT, was also reduced in cows with fatty livers. These results suggest that the decreased LCAT activity, which may be attributable to impaired hepatic secretion or to the suppression of the activity in the plasma by reduced concentrations of phosphatidylcholine and apolipoprotein A-I, resulted in the lower concentrations of cholesteryl esters. Because cholesteryl esters are utilized in steroidogenic tissues for the synthesis of steroid hormones such as progesterone and glucocorticoids, and insufficient supply of the cholesterols may be of relevance to the reduced fertility and immune competence observed in cows with fatty livers.

Animals↗
PubMed1997

Immunohistochemical detection of advanced glycosylation end-products in the peritoneum and its possible pathophysiological role in CAPD.

It has recently been suggested that advanced glycosylation end-products (AGEs) are formed in the peritoneum in patients on CAPD. However, the exact location of AGE accumulation, the relation with the duration of CAPD and its pathophysiological role in CAPD remain unclear. If the peritoneum is glycosylated, it could bring about altered peritoneal function. Therefore, the aim of this study is to clarify the localization of AGEs in the peritoneum in accordance with the duration of CAPD and to examine its relation to the peritoneal permeability. Fifteen non-diabetic patients were divided into three groups (each 5 patients) on the basis of the mean duration (D) of CAPD (Group 1, D = 0 month; Group II, D = 34 months; Group III, D = 84 months). The AGE staining by monoclonal anti-AGE antibody in the peritoneum and the four-hour peritoneal equilibration test (PET) were compared among these groups. AGE was absent or found only weakly in Group I. However, in groups II and III, AGE was moderately or strongly positive especially in the vascular walls and it was dominant in group III. PET revealed that peritoneal permeability for glucose, creatinine, beta2-microglobulin and albumin was increased in Group II as compared to Group I, and it was further increased in Group III. The results of this study indicate that AGEs become dominantly accumulated in the vascular wall in accordance with the prolongation of CAPD treatment, and this might play some roles for the increased permeability of the peritoneal membrane in CAPD.

Adult↗
PubMed1997

Calcium channel blockers suppress the contact hypersensitivity reaction (CHR) by inhibiting antigen transport and presentation by epidermal Langerhans cells in mice.

Since Langerhans cells (LC) are the principal antigen-presenting cells among epidermal cells, treatments suppressing LC function may inhibit CHR. Although calcium channel blockers (CCB) have been shown to suppress the functions of several immunologically active cells, little is known about their effect on LC. In this study we show that pretreatment with topical 1% nifedipine or verapamil HCl significantly suppressed both the sensitization and elicitation phases of a CHR in mice. We then investigated whether CCB affected LC. Flow cytometric analysis of regional lymph node cells obtained 24 h after applying FITC demonstrated that topical CCB treatment significantly reduced the percentage of FITC+ NLDC-145+ cells, suggesting that CCB had suppressed antigen transport by LC. In vitro treatment with nifedipine or verapamil significantly suppressed the antigen-presenting capacity of LC in a dose-dependent manner. In addition, in vitro CCB treatment reduced the percentage of class II MHC antigen-positive epidermal cells and significantly suppressed class II MHC and B7-1 levels in LC, as determined by flow cytometry and reverse transcriptase-polymerase chain reaction, whereas surface expression of B7-2 and mRNA was only weakly reduced. Neither expression of CD45 nor the percentage of CD45+ cells were affected, suggesting that the effects of CCB on LC were not due to cytotoxicity. Our results suggest that CCB inhibit CHR, at least in part, by suppressing the functions of LC.

Animals↗
PubMed1997

Synthesis and messenger ribonucleic acid expression of apolipoproteins E and A-I by the bovine corpus luteum during the estrous cycle and pregnancy.

In an attempt to characterize proteins secreted by the corpus luteum, explant cultures of luteal slices from cows taken on Days 3, 7, 11, 14, 17, and 19 of the estrous cycle, and Days 17, 88, 180, and > 240 of pregnancy were incubated with H-leucine for 24 h. Proteins in luteal-conditioned medium were separated by two-dimensional PAGE, transferred to polyvinylidene fluoride membrane, and subjected to N-terminal amino acid microsequencing. Microsequence analysis revealed that the bovine corpus luteum synthesized and released de novo synthesized apolipoproteins (Apo) E and A-I in culture during the estrous cycle and pregnancy. Release of Apo E was observed only on Day 3 of the estrous cycle. Release of Apo A-I was observed on Days 11, 14, 17, and 19 of the estrous cycle, and on all days of pregnancy examined. To demonstrate the presence of the appropriate mRNA and characterize the temporal relationship for these identified proteins, total RNA was isolated from corpora lutea on Days 2, 3, 7, 16, 17, and 20 of the estrous cycle, and on Days 17, 90, 170, 180, and 272 of pregnancy, and submitted to Northern and dot blot analysis. Apo E mRNA was expressed only on Days 2-3 of the estrous cycle and was not expressed on the other days of the cycle or during pregnancy. A single Apo E mRNA transcript about 1.0 kilobase (kb) in size was observed. Expression of Apo A-I mRNA was detected on all days of the estrous cycle and pregnancy examined. Apo A-I cDNA hybridized with a single mRNA transcript about 1.0 kb in size. Apo A-I mRNA levels did not differ among days of the estrous cycle, although higher levels of Apo A-I mRNA were observed during later stages of pregnancy. Serum concentrations of Apo A-I and progesterone were correlated across the estrous cycle but not during the prepartum period or after parturition. This study demonstrates for the first time that the corpus luteum synthesizes Apo E and Apo A-I and expresses their respective mRNAs. The pattern of expression of Apo E and Apo A-I mRNAs paralleled that of de novo synthesis of their respective proteins after incubation of luteal tissue with [H]leucine. The role of luteal apolipoproteins may involve an autocrine/paracrine function influencing luteal development, tissue remodeling, and steroidogenesis.

Amino Acid Sequence↗
PubMed1997

Acute cutaneous barrier perturbation induces maturation of Langerhans' cells in hairless mice.

Perturbation of the cutaneous water permeability barrier has been shown to result in many physiological events in keratinocytes, including upregulation of proinflammatory cytokine production. However, little is known about the effect of barrier disruption on Langerhans' cells (LC). In the present study, we examined whether acute barrier perturbation by acetone treatment or tape stripping affects the phenotypes and functions of LC in male hairless mice. Both procedures resulted in a two- to five-fold increase in the expression of MHC class II antigens, B7-2 and intercellular adhesion molecule-1 on LC, whereas no significant changes were detected in levels of B7-1. Levels of intracellular interleukin-1 beta, as determined by flowcytometry, were also increased 1 h after acetone treatment or tape stripping. LC obtained from barrier-disrupted mice induced a significant increase in syngeneic and allogeneic T-cell proliferation, compared to those from saline-treated mice. These results indicate that LC play a crucial role in maintaining cutaneous homeostasis against increasing exposure to external substances resulting from barrier disruption.

Acetone↗
PubMed1997

Effect of stages of lactation on the concentration of a 90-kilodalton heat shock protein in bovine mammary tissue.

From the normal mammary tissue of a Holstein cow in late lactation, a heat shock protein (90 kDa) was purified by ammonium sulfate fractionation and five-step column chromatography. From 70 g of tissue, 9.5 mg of this heat shock protein were obtained; samples had 98% purity and 19% recovery. The molecular mass of the 90-kDa heat shock protein was estimated to be 86 kDa by SDS-PAGE. Analysis of the amino-terminal amino acid sequence suggested that the protein had been purified as a mixture of two isoforms. The contents of the heat shock protein in cytoplasmic fractions of mammary tissues from Holstein heifers and cows at lactation and involution were measured by quantitative immunoblot analysis using rabbit antiserum raised against the purified heat shock proteins. The contents of the heat shock protein were higher in tissues from lactating cows than in those from heifers and involuting cows. The elevated concentrations of cytoplasmic 90-kDa heat shock protein in lactating tissue suggested that this protein is involved in mammary differentiation and lactation.

Amino Acid Sequence↗
PubMed1997

[Treatment results of radical prostatectomy for localized prostate cancer--biochemical failure analyzed from pathological findings at surgery].

OBJECTIVE: Recurrence is not rare after radical prostatectomy for localized prostate cancer. The treatment results of radical prostatectomy for localized prostate cancer was evaluated in this retrospective study. METHODS: A total of 36 patients with localized prostate cancer (clinical stage: A, B) were treated with radical prostatectomy. Kaplan-Meier product limit method analyzed from biochemical failure was used to study the treatment results of radical prostatectomy, and Cox's proportional hazards model was used to analyze the influence of pathological findings at surgery on biochemical failure. RESULTS: Of all 36 patients, 24 (67%) had pT3 (N0-2) disease, and these patients received adjuvant hormonal therapy after surgery. Overall freedom from biochemical failure at 5 years after surgery was 53% (pT1-2N0; 83%, pT3N0-2; 40%). No significant difference was seen in the freedom from biochemical failure between patients grouped by pathological classification (p = 0.106), tumor grade (p = 0.476), proximal and distal margin involvement (p = 0.095) and regional lymph node metastasis (p = 0.482), but a significant difference was seen between patients grouped by capsule involvement (freedom from biochemical failure at 5 years in cases with positive capsule: 30%, p = 0.023) and seminal vesicle involvement (freedom from biochemical failure at 5 years in cases with positive seminal vesicles: 26%, p = 0.014). Cox's proportional hazards model, on the other hand, showed only that seminal vesicle involvement significantly influenced on biochemical failure (p = 0.031). CONCLUSION: We confirmed a high likelihood of biochemical failure and presumably less favorable prognosis in patients with seminal vesicle involvement. These results indicated that candidates for surgery should be selected pathologically by excluding those with seminal vesicle involvement in the preoperative evaluation.

Aged↗
PubMed1997

Decreased serum apolipoprotein B-100 and A-I concentrations in cows with ketosis and left displacement of the abomasum.

OBJECTIVE: To assess the relevance of hepatic lipidosis (fatty liver) in the development of ketosis and left displacement of the abomasum (LDA). SAMPLE POPULATION: Sera from 22 healthy cows in early lactation, 21 cows with ketosis, and 19 cows with LDA, and serum and liver specimens from 35 slaughtered cows with or without fatty liver, ketosis, and/or LDA. PROCEDURE: Apolipoprotein B-100 and A-I concentrations were measured in sera of healthy farm cows and of farm cows with ketosis and LDA. Serum apolipoprotein concentration, together with liver triglyceride content, also were surveyed in a subset of slaughtered cows. RESULTS: Compared with those in healthy cows or controls, apolipoprotein B-100 and A-I concentrations were decreased in cows with ketosis and LDA. CONCLUSIONS: Decreases in apolipoprotein B-100 and A-I concentrations in cows with ketosis and LDA indicate that the 2 disorders may be intimately associated with fatty liver. CLINICAL RELEVANCE: Monitoring of the apolipoprotein B-100 and A-I concentrations during the stages of nonlactation and early lactation is helpful for detecting cows susceptible to ketosis and LDA.

3-Hydroxybutyric Acid↗
PubMed1997

Angiosarcoma of the scalp associated with renal transplantation.

A case of cutaneous angiosarcoma occurring in a 51-year-old male renal transplant patient is reported. Multiple violaceous nodules surrounded by poorly demarcated red to purple discoloration were found on his scalp. Immunosuppressants consisting of azathioprine and prednisolone had been administered during the 12-year period since the renal transplantation. We diagnosed the lesion clinically as a cutaneous angiosarcoma and performed a wide surgical excision. The histopathological findings confirmed the diagnosis and showed tumour cells in the peripheral margin. Postoperatively, the patient started immunotherapy with systemic administration of recombinant interleukin-2 (rIL-2), but he refused to continue it because of the acute rejection of the transplanted kidney induced by the rIL-2. Instead he received radiation therapy (total 7000 rad) of the scalp. Although no recurrence was noticed for 15 months after the completion of radiation, he died due to lung metastasis from angiosarcoma. We review the seven cases, including ours, of angiosarcoma after renal transplantation that are reported in detail in the literature.

Fatal Outcome↗
PubMed1997

Decreased serum apolipoprotein A-I concentrations in cows infected with Salmonella typhimurium.

Serum apolipoprotein A-I concentrations in cows infected with Salmonella Typhimurium were evaluated to assess its relevance in salmonellosis. Apolipoprotein A-I has been shown in rats to be secreted by the intestine as well as the liver. Clinical symptoms such as diarrhea revealed an outbreak of salmonellosis in 22 cows on a farm, and sera were obtained at 6 (acute phase), 16, 28 (convalescent period) and 42 d (postconvalescent period) after the outbreak. Apolipoprotein A-I concentrations (mean +/- SD, mg/mL), determined by ELISA, were 0.598 +/- 0.497 (day 6), 0.111 +/- 0.060 (day 16), 0.432 +/- 0.311 (day 28) and 0.727 +/- 0.516 (day 42). Compared with the concentration at day 42, those at 16 and 28 d were significantly (P < 0.01, P < 0.05) lower, but that at day 6 was not. The serum concentration of apolipoprotein B-100 (of liver origin in cattle) was unaltered during the course of salmonellosis. The concentration of apolipoprotein A-I was positively correlated with those of serum total cholesterol (r = 0.589, P < 0.01) and phospholipids (r = 0.590, P < 0.01). These results suggest that apolipoprotein A-I in cattle is in part of intestinal origin, and also that its decreased serum concentration in salmonellosis can be attributed to the reduced intestinal synthesis or secretion of this apolipoprotein. Moreover, as a potential carrier for dietary lipids such as cholesterol, determination of serum apolipoprotein A-I concentration is suggested to be useful when assessing the nutritional status of the affected cows.

Animals↗
PubMed1997

Secretion of apolipoprotein A-I by calf liver parenchymal cells.

OBJECTIVE: To determine: whether apolipoprotein A-I (apoA-I) is secreted by calf liver parenchymal cells; the isoprotein pattern and association with lipids of secreted apoA-I; and effects of steroid hormones on apoA-I secretion. SAMPLE POPULATION: 6 male Holstein calves (1 to 2 weeks old) as a cell culture source. PROCEDURE: apoA-I in culture medium was detected by immunoblot analysis, and its concentration was measured by use of an ELISA. The isoprotein pattern was analyzed by use of two-dimensional polyacrylamide gel electrophoresis. Associations of apoA-I with cholesterol and phospholipids were examined by ultracentrifugal analysis of the culture medium. RESULTS: Concentration of apoA-I in culture medium increased linearly up to 24 hours. The protein synthesis inhibitors, actinomycin D and cycloheximide, suppressed apoA-I accumulation in the medium in dose-dependent manner. Molecular mass of this protein in culture medium was 28 kd, and was indistinguishable from apoA-I of plasma. Four isoproteins with different isoelectric points (1 = 5.75; 2 = 5.67; 3 = 5.58; and 4 = 5.46) were detected. Of these, isoprotein 2 was the major species. By comparison, isoprotein 4 was the predominant species in plasma, and isoprotein 5 (isoelectric point = 5.38) was newly detected instead of isoprotein 1. Approximately 33% of apoA-I in culture medium was found in lipid-rich fractions, whereas the rest was found in nonlipoprotein fractions. Dexamethasone (10(-8) to 10(-6) M) significantly (P < 0.001) increased apoA-I concentration in the medium, and the stimulatory effect was significantly (P < 0.001) suppressed by the simultaneous addition of 10(-6) M progesterone. Progesterone itself (10(-8) to 10(-5) M) had little effect on apoA-I secretion; estradiol (10(-14) to 10(-8) M) also had no significant effect. CONCLUSIONS: apoA-I is synthesized by calf liver parenchymal cells, and the secreted protein is modified during circulation. Moreover, apoA-I synthesis and secretion by the cells appear not to be largely influenced by hormones, except for dexamethasone.

Animals↗
PubMed1997

Laparoscopic radical nephrectomy: the Nagoya experience.

PURPOSE: We evaluated the efficacy of laparoscopic radical nephrectomy for removing kidneys with small volume renal cell carcinoma. MATERIALS AND METHODS: 25 patients (19 men and 6 women, mean age 59) who had a kidney with small volume renal cell carcinoma (diameter less than 5 cm.), underwent laparoscopic radical nephrectomy. The kidney was dissected laparoscopically together with the adrenal gland, perirenal fatty tissue and Gerota's fascia. In 11 patients, we used the transperitoneal approach and in the remaining 14 we used the retroperitoneal approach, in which a working space is created by finger and balloon dissection. We maneuvered the kidney into the laparoscopy sack, which was then removed through an additional 5 to 6 cm. incision. RESULTS: All 25 kidneys were removed successfully. Mean operation time was 5.3 hours and mean estimated blood loss was 335 ml. There were 5 complications, including a patient who suffered an injury to the duodenum, which was treated by open duodenojejunostomy. Full convalescence occurred at an average 23 days. No metastatic disease, no local recurrence and no seeding at the port sites occurred during the followup of 7 to 49 months (mean, 22 months). CONCLUSIONS: Laparoscopic radical nephrectomy is recommended as a minimally invasive procedure for removing kidneys with small volume renal cell carcinoma.

Adult↗
PubMed1997

Reduced concentrations of apolipoproteins B-100 and A-I in serum from cows with retained placenta.

The purpose of the present study was to evaluate apolipoprotein B-100 and A-I concentrations in cows with retained placenta. Animals used were cows with retained placenta alone (n = 10), those with both retained placenta and ketosis (n = 7), and controls (n = 10). Apolipoprotein B-100 concentrations at 2 to 4 d after parturition were significantly (P < 0.01) decreased in cows with retained placenta alone (mean +/- SD, 0.084 +/- 0.029 mg/ML of serum) when compared with those in control cows (0.154 +/- 0.022 mg/mL). Apolipoprotein A-I concentrations (0.713 +/- 0.177 mg/ML) were also significantly (P < 0.05) lower than those of controls (0.895 +/- 0.159 mg/mL). These decreases were more distinct for apolipoproteins B-100 (55% of controls) than A-I concentrations (80% of controls). Concentrations of apolipoprotein B-100 (0.071 +/- 0.032 mg/mL; P < 0.01) and A-I (0.708 +/- 0.189 mg/mL; P < 0.05) in the cows with both retained placenta and ketosis were also reduced, when compared with values in controls. Other than apolipoproteins, cows with retained placenta alone had significantly (P < 0.01) higher serum nonesterified fatty acids, and lower triglyceride concentrations. Significantly (P < 0.01) higher nonesterified fatty acids and lower triglyceride concentrations were similarly observed in cows with both retained placenta and ketosis.

Analysis of Variance↗