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Biomedical subjects

K Takase

Publications and source records attributed to K Takase.

At least 163 records · Page 9Linked to original sources

Hemolytic anemia provoked by recombinant alpha-interferon.

A 30-year-old female with chronic hepatitis C treated with recombinant alpha-interferon developed serious hemolytic anemia after receiving 10 million units a day for 4 weeks. The results of Coombs' tests were negative before and after interferon therapy. The hemolytic anemia gradually improved after the withdrawal of recombinant alpha-interferon and the administration of methyl-prednisolone. The clinical course suggested that the recombinant alpha-interferon had provoked the hemolytic anemia.

Adult↗

Late onset hepatic failure due to hepatitis B virus with mutations in the pre-core region.

A 60-year-old man complained of severe general fatigue on October 11, 1992. Pertinent laboratory findings were: aspantate aminotransferase (AST) 1920 IU, alanine aminotransferase (ALT) 2050 IU, and total bilirubin (T. Bil) 124 micromol/l (normal range, 0-17 micromol/l). Virological assay revealed that hepatitis B surface antigen (HBsAg), anti-hepatitis B e (HBe), anti-HBc, and immunoglobulin M (IgM) anti-HBc were positive, and anti-HBs, HBeAg, and anti-delta antibody were negative. A diagnosis of acute hepatitis due to hepatitis B virus was made. Despite a decrease in transaminase, jaundice worsened and prothrombin time was prolonged. On the 60th day of hospitalization, massive ascites developed, but the patient's consciousness was not impaired. Although, albumin and diuretics were given, the ascites further increased. Paracentesis of 2000 ml of ascitic fluid was performed twice a week. On the 120th day of hospitalization, the patient passed black stools and he exhibited renal failure 3 weeks later. Although severe jaundice persisted, he was still alert. On the 150th day of hospitalization, massive gastrointestinal bleeding occurred, due to hemorrhagic gastritis. Despite receiving intensive care, the patient died. Determination of the HBV DNA sequence revealed two point mutations in the pre-core region; these have not been reported elsewhere.

DNA, Viral↗

MR findings of avulsive cortical irregularity of the distal femur.

Avulsive cortical irregularity, a benign condition occurring only among children and adolescents, has been known to simulate malignancy not only radiologically but also microscopically. Therefore, in addition to plain radiographs, further studies including by magnetic resonance (MR) imaging may occasionally be required. MR images of seven cases of avulsive cortical irregularity of the femur were reviewed. In all cases, the lesion appeared hypointense on T1-weighted images and hyperintense on T2-weighted images, with a dark rim on both sequences at or near the sites of the bony attachment of the medial head of the gastrocnemius muscle. In all cases, bilateral involvement was demonstrated by plain radiography, computed tomography, and/or MR imaging. The authors suggest that avulsive cortical irregularity involves both femora much more frequently than has been reported previously.

Adolescent↗

Vesnarinone inhibits nucleoside and nucleobase transport.

Vesnarinone is a novel synthetic oral inotropic agent that has been successfully used for treatment of patients with congestive heart failure. In addition to its cardiotonic activity, the drug has been proposed to have mild cytostatic and anti-HIV-1 effects. We have observed that vesnarinone profoundly inhibits radiolabeled thymidine and uridine incorporation into cells despite its modest inhibitory effect on DNA synthesis, RNA synthesis or cell proliferation. Here we demonstrate that vesnarinone inhibits both nucleoside and nucleobase transport in mammalian cells. This pharmacological action may be involved in some of its multiple biological effects.

Adenine↗

Comparison of agar-gel precipitin responses among strains of fowl adenovirus using antigens prepared from chorioallantoic membranes and chicken kidney cell cultures.

Agar-gel precipitin responses obtained for serologically different strains of fowl adenovirus (FAV) in tests using antigens prepared from FAV-infected chorioallantoic membranes (CAM antigen) and chicken kidney cell cultures (CKC antigen) were compared. Findings showed that both types of antigens exhibited less sensitivity to heterologous than to homologous antisera and that quantitative differences in sensitivity were present between serotypes. CAM antigens were more sensitive than CKC antigens to heterologous antisera. Polyvalent CAM antigens containing 2 or 3 antigens increased sensitivity in testing of field serum samples, resulting in a higher rate of detection.

Adenoviridae Infections↗

Apoptosis in the degeneration process of unfertilized mouse ova.

In mammals, ova which are not fertilized undergo degeneration. Thus, it seems that the ovum is programmed to die unless fertilization and embryogenesis occur, but little is known about the mechanism of such degeneration. To investigate this process, we observed the morphological changes of cultured unfertilized ova and stained DNA fragmentation by the modified TUNEL method (treating floating samples in liquid reagents) to detect apoptosis. Ova were collected from the oviducts of superovulated mice and cultured for observation. The number of morphologically abnormal ova with shrinkage of the ooplasm and cytoplasmic fragmentation, which are typical features of apoptosis, showed a significant gradual increase from 24 to 32 hr (p < 0.05) and an abrupt increase from 40 hr of incubation (p < 0.001). DNA fragmentation, which is one of the biological changes seen in apoptosis, was observed in the ooplasm of both intact and abnormal ova, cells with cytoplasmic fragmentation, and in the first polar body at the time of ovum collection as well as after incubation. These findings demonstrate that apoptosis is related to the process of degeneration in the mouse ovum and first polar body.

Animals↗

A clinical study of lectin-reactive alpha-fetoprotein as an early indicator of hepatocellular carcinoma in the follow-up of cirrhotic patients.

Levels of two types of lectin-reactive alpha-fetoprotein (AFP), designated AFP-L3 and AFP-P4+P5, were analyzed with Lens culinaris agglutinin A and AFP-P4+P5 with erythroagglutinating phytohemagglutinin, respectively, in an attempt to determine the utility and significance of these macromolecules as early indicators of hepatocellular carcinoma during the periodic follow-up of cirrhotic patients. The subjects were 51 of 190 consecutive cirrhotic patients in whom hepatocellular carcinoma developed during a 6-year follow-up period and 21 cirrhotic patients without hepatocellular carcinoma. Serum AFP levels were of limited value to diagnose and predict hepatocellular carcinoma. The relative levels of AFP-L3 and AFP-P4+P5 in patients with hepatocellular carcinoma at the time of tumor detection were significantly higher than those in patients with cirrhosis. The sensitivity was 61%, and the specificity was 90%. Fourteen patients (48%) of 29 patients with small hepatocellular carcinomas less than 2 cm in diameter showed elevated percentage of lectin-reactive AFP. Retrospective examination of 21 patients who were positive for lectin-reactive AFP at diagnosis of hepatocellular carcinoma showed that 41% of them had already expressed lectin-reactive AFP 12 months before the direct detection of hepatocellular carcinoma by diagnostic imaging. These results lead us to conclude that the level of lectin-reactive AFP is a suitable predictive marker for the early recognition of hepatocellular carcinoma in the follow-up of patients with cirrhosis, and that measurements of the level of lectin-reactive AFP should be added to the screening methods that are now in use.

Biomarkers, Tumor↗

[Acute pancreatitis associated with acute intermittent porphyria].

Pancreatic involvement associated with acute intermittent porphyria is rare. There were only nine cases reported until now which have pancreatic disease and AIP, one case with chronic pancreatitis, one with cystadenocarcinoma and chronic pancreatitis, one with transient macroamylasemia and the others with acute pancreatitis. The cause of these complications in these patients is uncertain. However, in our case, it is possible that AIP might have caused the acute pancreatitis, since this patient developed acute pancreatitis following the attack of AIP. It seems to be necessary to pay attention to the combination of these diseases.

Acute Disease↗

Toxicity study of the angiotensin converting enzyme inhibitor rentiapril in rats.

A three-months toxicity study of an angiotensin converting enzyme (ACE) inhibitor, rentiapril (CAS 80830-42-8), was performed in Sprague-Dawley rats by oral administration. The dose levels of 0, 30, 125, 500 and 1000 mg/kg were tested in both sexes, in which each experimental group comprised 10 rats. Another ACE inhibitor, captopril, was used as a reference compound. Rentiapril at the highest dose of 1000 mg/kg caused low food consumption and death of some animals with signs of bloody feces and anemia. In males and females receiving 500 and 1000 mg/kg, there were low body weight gain, increases in water intake, urine volume and serum BUN level, and decreases in levels of various erythrocytic parameters. Kidney weight was increased dose-dependently in both sexes. Histopathologically, renal changes in the 500 and 1000 mg/kg groups consisted of proximal tubular degeneration, juxtaglomerular cell hyperplasia and interstitial cell infiltration. Similar, but mild, changes in proximal tubules were present in the female 125 mg/kg group. Dead animals from the highest dose groups further showed gastrointestinal hemorrhagic erosion and/or ulcer, decreased bone marrow erythropoiesis and hepatocytic vacuolar degeneration. There was no pathological alteration in rats from other rentiapril-treated groups, as well as in controls. These results indicate that the no-effect dose of rentiapril in rats by three months oral administration is 30 mg/kg in female and 125 mg/kg in male, and suggest that, like other ACE-inhibitors, this compound also has a toxic potential to affect renal tissues.

3-Mercaptopropionic Acid↗

Rapamycin selectively inhibits translation of mRNAs encoding elongation factors and ribosomal proteins.

The immunosuppressant rapamycin (RAP) has been demonstrated to specifically inhibit the activity of p70 S6 kinase (p70s6k) and subsequent phosphorylation of ribosomal S6 protein in mammalian cells. Addition of RAP to proliferating lymphoid cells resulted in inhibition of protein synthesis before any changes in the rate of cell proliferation. When the cellular composition of proteins was examined by gel electrophoresis, RAP dramatically inhibited synthesis of selective proteins, particularly elongation factor 2 (eEF-2). The inhibition of eEF-2 synthesis by RAP was at the translational level. Further, RAP inhibited the polysomal association of mRNAs encoding not only eEF-2 but also elongation factor 1-alpha and ribosomal proteins without affecting mRNA translation of any of a number of nonribosomal proteins. Since levels of activity of p70s6k are correlated with the rate of biosynthesis of eEF-2, p70s6k might be involved in coordinate translational regulation of ribosomal protein mRNAs in higher eukaryotes, which have a conserved sequence at their 5' end. Specific inhibition of ribosomal protein synthesis likely explains the differential antiproliferative effect of RAP on proliferating and mitogen-activated quiescent cells.

Base Sequence↗

Site-directed mutagenesis reveals critical importance of the catalytic site in the binding of alpha-amylase by wheat proteinaceous inhibitor.

A bacterial alpha-amylase from Bacillus subtilis was found to be strongly inhibited by wheat alpha-amylase inhibitors 0.53 and 0.19, which had previously been thought specific for animal alpha-amylase. Inhibition and gel filtration studies of site-directed mutants of B. subtilis alpha-amylase with the inhibitors indicated a direct correlation between the alpha-amylase activity and the inhibitory effect of inhibitor binding. A mutant enzyme His 180-->Asn, which was 20 times less active in terms of kcat than the wild type, was less sensitive to inhibition by similar degrees, while the specificity for 0.53 and 0.19 changed significantly as a result of the mutation. Catalytic-site mutants that were completely devoid of catalytic activity virtually lost the ability to bind inhibitors, even though they retained high affinities for substrates. The results show that the integrity of the catalytic site is crucial for inhibitor binding and, despite the previously observed tight binding, reveal a subtle nature of the interaction between alpha-amylase and the wheat inhibitor, which leads to a proposal of a two-step mechanism for the binding interaction.

Bacillus subtilis↗

Sequencing and characterization of the ntp gene cluster for vacuolar-type Na(+)-translocating ATPase of Enterococcus hirae.

We have previously reported the DNA and amino acid sequences for the three genes (ntpA, ntpB, and ntpK) encoding the A, B, and K (proteolipid) subunits, respectively, of Na(+)-translocating ATPase of a eubacterium Enterococcus hirae (Kakinuma, Y., Kakinuma, S., Takase, K., Konishi, K., Igarashi, K., and Yamato, I. (1993) Biochem. Biophys. Res. Commun. 195, 1063-1069). In this paper we report the entire nucleotide sequence of the ntp gene cluster coding for this multisubunit enzyme. The cluster contained eight other genes; the order of these 11 genes was ntpF, -I, -K, -E, -C, -G, -A, -B, -D, -H, and -J, encoding proteins with predicted molecular weights of 14,255, 75,619, 16,036, 22,699, 38,162, 11,409, 65,766, 51,139, 27,093, 7,164, and 48,869, respectively. The deduced amino acid sequences of these products suggested that NtpI and NtpJ are hydrophobic proteins and others are hydrophilic. The ntpI gene product, which possesses six membrane-spanning segments in its carboxyl-terminal half, resembled the 116-kDa subunit of vacuolar (V)-ATPase in clathrin-coated vesicles. In addition, the NtpE, NtpC, NtpG, and NtpD proteins resembled bovine kidney ATPase E subunit, Saccharomyces cerevisiae Vma6p, Manduca sexta V-ATPase 14-kDa subunit, and Sulfolobus acidocaldarius gamma subunit, respectively, although the similarities between their amino acid sequences were moderate. Other gene products (NtpF and NtpH) did not show significant sequence similarity to other V-ATPase subunits. Since NtpA, NtpB, and NtpK are homologous counterparts of V-ATPase, these findings suggest that the molecular architecture of E. hirae Na(+)-ATPase complex corresponds to the V-type H(+)-ATPase complex distributed in various eukaryotic endomembrane systems. The sequence of the NtpJ product was similar to those of K+ transport systems of S. cerevisiae (Trk1 and Trk2); its meaning will be discussed. This is the first demonstration of a eukaryotic V-ATPase-like Na+ pump in bacteria.

Adenosine Triphosphatases↗

Sevoflurane and oxygen anaesthesia following administration of atropine-xylazine-guaifenesin-thiopental in spontaneously breathing horses.

The effects of sevoflurane-oxygen anaesthesia at a light-surgical depth on clinically important features were evaluated in spontaneously breathing horses that received atropine, xylazine, and guaifenesin-thiopental. Mean end-tidal concentrations of sevoflurane ranged from 1.6 to 2.3% during 90 min maintenance. Recovery from anaesthesia was extremely rapid and smooth. Heart rates did not significantly change after anaesthesia. Arrhythmia was not observed. Mean arterial pressure (mean +/- SD) ranged from 86 +/- 17 to 98 +/- 5 mmHg during anaesthesia. Minute ventilation was low due to decreased respiratory rates during anaesthesia. Changes in arterial blood gases and pH demonstrated respiratory acidosis during anaesthesia. Haematological findings revealed haemodilution during anaesthesia. Serum potassium decreased slightly during anaesthesia, but other serum biochemical values did not significantly change for 7 days post-anaesthesia. These results suggest that sevoflurane may be an effective inhalant anaesthetic which produces a rapid recovery from anaesthesia in horses.

Anesthesia, Inhalation↗

Renal cell carcinoma associated with chronic renal failure: evaluation with sonographic angiography.

PURPOSE: To determine the value of sonographic angiography for diagnosis of renal cell carcinoma (RCC) in patients with chronic renal failure (CRF). MATERIALS AND METHODS: The authors compared findings from sonographic angiography, conventional ultrasound (US), computed tomography (CT), and conventional angiography in 15 patients with CRF in whom RCC was suspected. All of these patients subsequently underwent nephrectomy. RESULTS: RCC was demonstrated pathologically in 13 patients, whereas two had benign lesions only. Sonographic angiography depicted tumor enhancement in all patients with RCC except one; no enhancement was shown in the two patients with benign lesions. Conventional angiography depicted tumors stained by contrast material in nine of 13 patients with RCC, and CT depicted tumor enhancement in 10 of 13 patients. US was useful for the detection of nodules but did not allow differentiation of malignant from benign lesions. CONCLUSION: Sonographic angiography has a possible role in the detection of small nodules in patients with CRF.

Adult↗