Search PubMed⌕ Search

Biomedical subjects

N Katoh

Publications and source records attributed to N Katoh.

At least 109 records · Page 6Linked to original sources
PubMed1995

Enzyme-linked immunosorbent assay for serum apolipoprotein B-100, a major triglyceride-transport protein in dairy cows.

An ELISA was developed to determine serum concentration of apolipoprotein B-100, a major triglyceride-binding protein in very low-density lipoproteins and a putative maker for hepatic lipidosis of dairy cows. Serum apolipoprotein B-100 was prepared electrophoretically, and antibodies to this protein were raised in rabbits. The antiserum prepared was further purified by affinity chromatography, using bovine serum albumin-Sepharose 4B, to remove antibodies to albumin. For the ELISA, addition of 2-mercaptoethanol to the coating buffer (50 mM sodium carbonate, pH 9.6) was required to evaluate apolipoprotein B-100 concentration in serum. The ELISA developed was sensitive (detection limit was 300 to 400 ng/ml of serum) and reliable (coefficients of variance were in the range of 3.3 to 7.6%). By use of the established ELISA, the serum apolipoprotein B-100 concentration was found to be significantly (P < 0.01) lower during the early lactating stage than during other stages of lactation. Reduced hepatic synthesis or secretion of apolipoprotein B-100 during the early lactating stage, together with the excess uptake by the liver of serum nonesterified fatty acids, is suggested to be relevant in the accelerated accumulation of triglycerides in the liver of dairy cows during the periparturient period.

Animals↗
PubMed1994

Reduced protein kinase C activity and endogenous protein phosphorylation in ethionine-induced fatty liver in cows.

Protein kinase C (PKC) activity was evaluated and the phosphorylation of its endogenous substrates was explored in fatty liver induced by administration of ethionine (an analogue of methionine) to cows in order to assess the relevance of PKC-dependent phosphorylation in the development of fatty liver. PKC activity was decreased in both the cytosolic and the total particulate fractions from fatty livers, compared to the corresponding fractions from control liver. The mode of activation by the PKC cofactors (1-oleoyl-2-acetyl-sn-glycerol, 12-O-tetradecanoylphorbol-13-acetate, phosphatidyl-serine and Ca2+) was similar in both control and fatty livers, suggesting a quantitative but not a qualitative change in PKC in fatty liver. At least three substrate proteins (34 kDa, 26 kDa and 19 kDa) were found in the cytosolic fraction and their phosphorylation was reduced in fatty liver. These results suggest that impairment of the signal transduction pathway mediated by PKC is involved in the pathogenesis of fatty liver in cows.

Animals↗
PubMed1994

Laparoscopic nephrectomy, radical nephrectomy and adrenalectomy: Nagoya experience.

A total of 37 patients with various renal and adrenal diseases underwent laparoscopic nephrectomy, radical nephrectomy and adrenalectomy since July 1991. The underlying diseases included renal calculi, vesicoureteral reflux, ureteropelvic junction obstruction, ureteral stenosis, ectopic ureter, vascular disease, renal cell carcinoma and adrenal tumors. Twenty-nine kidneys (including 5 with renal cell carcinoma) and 5 adrenal glands were removed successfully. Three cases failed because of dense adhesion to the surrounding structures, hemorrhage from the renal vein and hemorrhage from the vena cava, respectively. Of the remaining 34 patients 3 required additional open laparotomy to control bleeding or remove lost calculi. Mean operating time was 265 minutes for nephrectomy, 383 minutes for radical nephrectomy and 199 minutes for adrenalectomy, and mean estimated blood loss was 455 ml., 430 ml. and 80 ml., respectively. Average hospital stay was 10 days for the 31 patients without open laparotomy and convalescence was completed by postoperative day 21. These results indicate that laparoscopic surgery for renal and adrenal disease is a feasible, minimally invasive procedure. In the case of laparoscopic radical nephrectomy, however, longterm followup is necessary to confirm the efficacy.

Adolescent↗
PubMed1994

Laparoscopic radical nephrectomy for renal cell carcinoma: early experience.

We developed a laparoscopic radical nephrectomy for malignant disease of the kidney and successfully performed the operation in six patients between July 1992 and October 1993. This procedure is basically derived from that of Clayman and associates. A CO2 pneumoperitoneum is induced, and five trocars are introduced into the abdominal cavity through the lateral abdominal wall. The kidney is removed en bloc together with the adrenal gland, perirenal fatty tissue, and Gerota's fascia. The free kidney is put into a laparoscopy sack, and the sack is pulled out through a 5- to 6-cm incision in the abdominal wall without morcellation to allow complete pathologic examination. By this procedure, right nephrectomy was performed in four patients and left nephrectomy in two patients. The mean operative time was 6 hours and 13 minutes, and the mean blood loss was 430 mL. There were no severe complications. The average hospital stay was 11 days, and the average time to full convalescence was 21 days. Pathologic examination revealed renal cell carcinoma in five patients and nephroblastoma in one. Of the patients with renal cell carcinoma, the stage was pT1pN0pM0 in three patients and pT2pN0pM0 in two. There has been no recurrent disease in these six patients with a mean follow-up period of 9.5 months.

Adult↗
PubMed1994

Mucinous carcinoma of the skin: report of a case with DNA cytofluorometric study.

A 62-year-old man with a mucinous carcinoma of the skin on the left cheek is described. The excised specimen showed a characteristic histopathologic picture. The findings from histochemical, immuno-histochemical, and electron microscopic examinations suggested an eccrine differentiation of the tumor cells. The removed tumor was examined using DNA cytofluorometry in order to analyze the cell kinetics and to estimate its biological behavior and prognosis. The tumor cells showed a diploid mode with a small number of polyploid cells. Only a small number of cells in the S and G2/M phase ranges were detected. After four years, there has been no evidence of tumor recurrence nor metastasis. The results of DNA ploidy analysis were thus compatible with the nature of slow growth with a good prognosis in this case.

Adenocarcinoma, Mucinous↗
PubMed1994

Fallopian tube disease: limited value of treatment with fallopian tube catheterization.

PURPOSE: Therapeutic role of fallopian tube catheterization was prospectively studied in patients with bilateral fallopian tube obstruction. MATERIALS AND METHODS: Catheterization was performed in 42 patients with bilateral obstruction; 36 of the patients (67 fallopian tubes) underwent recanalization. RESULTS: Fifty-two tubes with 54 proximal obstructions were successfully recanalized (technical success rate, 96%), 36 with selective catheterization and 16 with coaxial techniques. Among 13 tubes blocked at the distal portion of the tube, six tubes were negotiated. Perforation or subintimal injury occurred in three tubes, and one patient eventually had a tubal pregnancy. During follow-up of 3 months to 4 years, five patients had conceived, including the patient with a tubal pregnancy and one patient who experienced spontaneous abortion during the first trimester. CONCLUSION: Fallopian tube catheterization is technically highly successful and diagnostically useful. However, its role in treating fallopian tube diseases is limited, and patients with distally blocked tubes are not good candidates for this procedure.

Adult↗
PubMed1994

CT-guided biopsy of the chest: usefulness of fine-needle core biopsy combined with frozen-section pathologic diagnosis.

PURPOSE: To improve the diagnostic accuracy of computed tomography (CT)-guided biopsy of the chest. MATERIALS AND METHODS: The usefulness of fine-needle core biopsy combined with immediate frozen-section diagnosis by pathologists was prospectively studied. Fifty-five biopsies of the chest were performed under CT guidance in 55 patients with 36 malignant and 19 benign processes. Initial biopsy was always attempted with a 21-gauge modified Menghini needle; tissue samples were sent to the pathology department immediately after biopsy for pathologic diagnosis of the frozen sections. RESULTS: In 47 of 55 lesions (85%) sufficient materials for diagnosis were obtained and enabled correct final diagnosis. Specific histologic diagnosis was possible in 25 (74%) of 34 malignant and 10 (77%) of 13 benign lesions. In all of the eight other lesions, cytologic diagnosis of aspirated material was correct. No false-positive or false-negative results have occurred. CONCLUSION: Histologic diagnosis with frozen sections improves diagnostic accuracy of chest biopsy; immediate pathologic diagnosis is an encouraged adjunct.

Adolescent↗
PubMed1994

[End stage polycystic kidney disease: the study for upper urinary tract infection & hemorrhage into the cysts].

The results have been reviewed of 41 patients with end stage polycystic kidney disease on maintenance hemodialysis. The patients ranged in age from 34 to 83 years with an average age of 55 years and 25 patients were male, 16 were female. The duration of maintenance hemodialysis in the patients was from 1 to 200 months with an average time of 69 months. Infection of the cysts and pyelonephitis occurred 22 times in 13 patients (32%) and hemorrhage into the cysts occurred 15 times in 13 patients (32%). To control the infection, bilateral nephrectomy was required in 10 patients and 1 patient was undergone unilateral nephrectomy. Of 13 patients with the hemorrhagic cysts, 5 were undergone bilateral nephrectomy and 2 were undergone unilateral nephrectomy. Six patients died during follow up and the cause of death were 1) cardiac failure, 2) cerebral hemorrhage, 3) cardiac infarction, 4) pneumonia after nephrectomy, 5) massive bleeding after second operation for adhesive ileus due to first nephrectomy, 6) unknown. Fourteen patients but one undergone bilateral nephrectomy were followed for an average time of 70 months after nephrectomy. Such as complication due to bilateral nephrectomy, anemia occurred in 13 patients (93%) and hypotension occurred in 5 patients (33%). Bilateral nephrectomy was effective procedure in safety for end stage polycystic kidney patients with the infection and the hemorrhagic cysts because anemia and hypotension which occurred usually after bilateral nephrectomy now can be controlled goodly.

Adult↗
PubMed1994

Dexamethasone-induced haptoglobin release by calf liver parenchymal cells.

Parenchymal cells were isolated from the liver of male calves, and monolayer cultures formed were treated with glucocorticoids to examine whether haptoglobin, appearance of which is associated with hepatic lipidosis (fatty liver) in cattle, is induced by steroid hormones. Without addition of dexamethasone, only trace amounts of haptoglobin were detected in culture medium. With addition of dexamethasone (10(-12) to 10(-4) M), considerable amounts of haptoglobin were released into the medium. Maximal release was observed at concentrations of 10(-8) to 10(-6) M dexamethasone. Haptoglobin release was similarly induced by cortisol, although the effect was less potent than that of dexamethasone. Actinomycin D (a known protein synthesis inhibitor) dose-dependently reduced amounts of haptoglobin released in response to 10(-8) M dexamethasone. Dexamethasone also induced annexin I, which is known to be synthesized in response to glucocorticoids. Dexamethasone treatment resulted in reduced protein kinase C activity in the cell cytosol, which has been shown to be an early event in dexamethasone-treated cells. Other than glucocorticoids, estradiol induced haptoglobin release, whereas progesterone was less effective. The association of haptoglobin with hepatic lipidosis can be reasonably explained by the fact that haptoglobin production by the liver is induced by glucocorticoids and estradiol, and these steroid hormones are triggers for development of hepatic lipidosis in cattle.

Animals↗
PubMed1994

[Evaluation of the mechanism of endothelin-induced rat gastric mucosal lesion formation].

There are several reports on the gastric mucotoxic effect of endothelin (ET). The mechanism of this effect, however, remains largely unknown. To evaluate this, we assessed the gastric injury and changes in gastric mucosal blood flow induced by ET using ONO-1078, a sulfide peptide leukotriene (LT) antagonist, CV-3988, a platelet-activating factor (PAF) antagonist, and diltiazem, a Ca2+ channel blocker. In fasted and anesthetized rats, 2 nmol/kg of ET was infused for 30 min into splenic artery to deliver the drug as much as selectively to the stomach. Ninety minutes after beginning the drug infusion rats were killed and gastric mucosal damage in the removed stomachs was assessed. Gastric mucosal blood flow (GMBF) was measured for 90 min with a 30 min-interval by the laser Doppler flowmetry method. ET induced severe gastric mucosal damage, which was characterized by congestion of mucosal capillary and accompanied by significant reduction of GMBF, as compared with control. However, these mucotoxic effect of ET was significantly inhibited by 20 mg/kg of ONO-1078 given i. g. 60 min before ET infusion and i. v. administration of 10 mg/kg of CV-3988 and 1 mg/kg of diltiazem 30 min prior to ET. From these results, we conclude that PAF, LT and Ca2+ may play important pathogenetic roles as chemical mediators in the mechanism of the formation of ET-induced gastric mucosal lesions.

Animals↗
PubMed1993

Modulation by sphingosine of substrate phosphorylation by protein kinase C in bovine mammary gland.

The effect of sphingosine on the phosphorylation of endogenous proteins by protein kinase C (PKC) was investigated in bovine mammary gland. Several proteins were shown to be substrates for PKC in both cytosolic and total particulate fractions by phosphorylation in the absence or presence of 1-oleoyl-2-acetyl-sn-glycerol, phosphatidylserine (PS) and Ca2+. At concentrations of 83 microM or less, sphingosine inhibited phosphorylation of several substrates for PKC in both fractions. Phosphorylation of cytosolic 36 kDa, 21 kDa and particulate 36 kDa proteins was particularly sensitive to sphingosine. Cytosolic 97 kDa phosphorylation (which was enhanced by Ca2+ alone) was also sensitive to sphingosine. The inhibition was reversed by excess addition of lipid cofactors, particularly PS, but not by Ca2+. At higher concentrations (167 and 417 microM), in addition to the inhibition seen at lower concentrations, sphingosine stimulated phosphorylation of several proteins, including cytosolic 19 kDa and particulate 53 kDa, which were not detected in the absence of sphingosine. The sphingosine-induced phosphorylation disappeared with excess addition of PS, but not with addition of Ca2+. The results point toward the importance of the interaction of sphingosine with membrane phospholipids in the signal transduction pathway mediated by PKC-dependent phosphorylation in bovine mammary gland.

Animals↗
PubMed1993

Dystrophic calcinosis of the penis.

A 22-year-old man had had a dome-shaped tumor on his penis for one year. Neither his particular past history nor family history was available. The excised specimen contained numerous von Kossa-positive deposits. Four types of histologic pattern were identified: 1) a cystic structure filled with amorphous material lined by a few layers of epithelial cells, 2) a cyst containing calcified deposits in the keratinous material, 3) a large calcified nodule lined by attenuated epithelial cyst walls, 4) numerous calcium collections without an epithelial wall. The cystic structure showed the histologic features of syringoma or sweat duct milia. The luminal cells of the cyst showed positive immunoreactivity for both keratin and carcinoembryonic antigen. These findings suggested that the keratinous contents of syringoma had gradually calcified, the cyst wall had been attenuated, and, finally, numerous calcium collections without an epithelial wall were formed. Our case further supported the hypothesis that penile calcinosis as well as scrotal calcinosis might derive from syringoma.

Adult↗
PubMed1993

Protein kinase C and its endogenous substrate proteins in isolated cow liver parenchymal cells.

Protein kinase C activity was evaluated and its endogenous substrate proteins were explored in isolated cow liver parenchymal cells. Protein kinase C activity was detected in both cytosolic and total particulate fractions of the cells. At least four proteins in cytosolic and seven proteins in total particulate fractions were found to be substrates for protein kinase C. These results suggested that protein kinase C-catalyzed protein phosphorylation was involved in the regulation of functions of cow liver parenchymal cells.

Adenosine Triphosphate↗
PubMed1993

Induction of serum haptoglobin by administration of ethionine to cows.

In order to assess the association of cow serum haptoglobin with fatty liver, haptoglobin concentrations were evaluated by single radial immunodiffusion in sera from cows after administration of ethionine (an analogue of methionine). Haptoglobin concentrations were found to be increased in the sera of the ethionine-administered cows. This result suggests that the induction of haptoglobin is associated in the pathogenesis of fatty liver.

Animals↗
PubMed1993

Appearance of haptoglobin in serum from cows at parturition.

Haptoglobin (Hp) concentrations were evaluated in 42 cow sera at around parturition by single radial immunodiffusion using anti-cow Hp rabbit serum. At parturition, Hp was detected in 31 of 42 cows. The detection rate (74%) was significantly higher than those before (0-10%) and after parturition (5-21%). At parturition, serum concentrations of cortisol and non-esterified fatty acids were significantly higher than those before and after parturition. A significantly lower concentration of serum triglycerides at parturition, compared to the values before parturition, was also observed. From these results, Hp is considered to be associated with fatty liver development of cows, because fatty liver particularly occurs in the peripartum period.

Animals↗