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Biomedical subjects

T Tsukada

Publications and source records attributed to T Tsukada.

At least 127 records · Page 7Linked to original sources
PubMed1994

Simple and rapid detection of cholesteryl ester transfer protein deficiency by using nonradioisotopic single-strand conformation polymorphism analysis.

We developed a polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis technique by using silver staining to detect the G-->A point mutation of intron 14 of the cholesteryl ester transfer protein (CETP) gene, which is a common mutation in CETP deficiency. After conventional PCR, amplified DNA was heated and subjected to electrophoresis in polyacrylamide gel containing glycerol. The gel was then stained with silver to identify DNA bands. With this technique, we examined 40 subjects with high concentrations of high-density lipoprotein cholesterol (> or = 1 g/L) and found one homozygote and eight heterozygotes. The procedure is suitable for screening because it is quick and does not require radioactive materials or restriction enzymes.

Base Sequence↗
PubMed1994

[An international attempt for standardization on terminology and methodology in hemostasis and thrombosis].

Scientific and Standardization Committee (SSC) of International Thrombosis and Hemostasis has acted its activity since 1955 for establishing international concept on terminology, methodology in the fields of blood platelets, coagulation and fibrinolysis. Among the reports from 15 sub-committee in 1993 meeting, some clinically interesting topics are reported. In von Willebrand factor (vWF) Subcommittee, new classification of von Willebrand disease including new variant of VFW which shows defect on factor VIII binding capacity, is proposed. In Control of Anticoagulation Subcommittee, the necessity of coagulation monitoring during low molecular weight heparin (LMWH) administration was discussed. For prophylaxis use, monitoring is unnecessary except patients having renal failure or high-low body weight. For the treatment of venous thrombosis once or twice monitoring every 10 days would be necessary. In Lupus anticoagulant (LA)/phospholipid dependent antibodies Subcommittee, results of 3rd international survey for LA sent to 38 laboratories in 16 countries including Japan were reported. Most laboratory used APTT and dRVVT simultaneously as screening tests. Sensitivity and specificity of confirmatory test for LA are compared; the best one was Staclot LA and the second was DVVT.

Blood Coagulation Factors↗
PubMed1993

Purification and characterization of an alpha-L-fucosidase from Pomacea canaliculata.

An alpha-L-fucosidase (EC 3.2.1.51) was isolated from the hepatopancreas of Pomacea canaliculata. The enzyme was purified 285-fold from the crude enzyme extract by procedures involving first heat treatment, ammonium sulfate fractionation, second heat treatment, and chromatography on DEAE-Sepharose, hydroxylapatite, and L-fucosylamine-CH-Sepharose. When assayed by using p-nitrophenyl glycosides as substrates, the final preparation was free from other glycosidase activities and gave a single protein band which corresponded to alpha-L-fucosidase activity on disc gel electrophoresis. The molecular weight of the enzyme was estimated to be 260,000 by Sephacryl S-300 column chromatography. The enzyme has two optimum pH values, 2.5 and 5.0, and the apparent Km value and the maximum velocity for p-nitrophenyl alpha-L-fucoside at both pH were calculated to be 0.45 mM and 1.46 mumol/min/mg of protein, respectively. The enzyme was shown to hydrolyze the Fuc alpha 1-->2Gal, the Fuc alpha 1-->4GlcNAc, and the Fuc alpha 1-->6GlcNAc linkages, but hardly acts on the Fuc alpha 1-->3GlcNAc linkage in various oligosaccharides.

Ammonium Sulfate↗
PubMed1993

A novel ES cell line, TT2, with high germline-differentiating potency.

In producing mutant mice by gene-targeting and gene-trapping in embryonic stem (ES) cells, the efficient colonization of the mutant ES cells into germline is still a critical matter. We have established a new line of ES cells, TT2, from an F1 embryo between a C57BL/6 female and a CBA male. When the TT2 cells were injected into blastocysts, the colonization into each tissue was very low. However, when injected into eight-cell embryos, the cells segregated inside the blastomeres, localized in an inner cell mass of blastocysts developed 1 day later, and colonized efficiently in each tissue of the pups. The pups were disproportionately male, about half of which were composed of TT2-derived cells primarily; in more than 70% of the males, TT2-derived cells were dominant, accounting for over half of the total cells. When these males were mated, they exclusively yielded TT2-derived offspring. The germline-differentiating potency was stable during 3 weeks of culture. Twenty-one of 24 mutant clones independently isolated yielded germline chimeras, and 19 clones yielded them in a rate comparable to that of the parent cells. Thus, TT2 cells can serve as a valuable vehicle for the production of mutant mice.

Animals↗
PubMed1993

Liver sarcoidosis showing low-density intrahepatic septa on postcontrast computed tomography.

The authors present a patient with massive liver sarcoidosis, showing only slight hepatomegaly on precontrast computed tomogram and multiple low-density intrahepatic septa on postcontrast computed tomogram. Sarcoidosis frequently involves the liver, but rarely shows abnormal findings other than hepatomegaly on computed tomograms. Only a few cases have demonstrated a low density intrahepatic area on computed tomograms. In this report, we present a patient with massive liver and pulmonary sarcoidosis, showing low density intrahepatic septa and pulmonary fibrosis on computed tomograms.

Humans↗
PubMed1993

Bacterial lipopolysaccharide-induced expression of interleukin-6 messenger ribonucleic acid in the rat hypothalamus, pituitary, adrenal gland, and spleen.

Whereas the stimulatory effect of interleukin-6 (IL-6) on the hypothalamic-pituitary-adrenal (HPA) axis is well established, its mode of action in this axis has yet to be fully elucidated. To further study the role of IL-6 in the HPA axis, we compared the expression of IL-6 messenger RNA (mRNA) in the rat hypothalamus, pituitary, and adrenal gland with that in the spleen after ip or intracerebroventricular (icv) administration of bacterial lipopolysaccharide (LPS). After either ip or icv administration, LPS induced the expression of IL-6 mRNA, which consists of 1.2 kilobases (kb) and 2.4 kb subclasses, in all these tissues of the HPA axis as well as in the spleen. Although we used 100 times less amount of LPS for the icv administration than that used for ip LPS, plasma ACTH levels in both the conditions rapidly reached comparable levels. This icv dose induced IL-6 mRNA expression in the hypothalamus faster than ip dose but also stimulated IL-6 mRNA expression in the hypothalamus, pituitary, and adrenal gland more effectively and smoothly than the ip LPS dose did. Northern blot analysis revealed that in the hypothalamus, pituitary, and adrenals, the predominant subclass of IL-6 mRNA was not 1.2 kb but 2.4 kb. In contrast, this subclass was the minor component in the spleen induced under the same circumstances. These findings indicate that IL-6-synthesizing cells in the HPA axis differ in character from those in the spleen, and that LPS applied in vivo may modulate IL-6 expression in these cells directly and/or indirectly through secondarily activated functions in the neuronal or endocrine systems.

Animals↗
PubMed1993

[Experience of laparoscopic pelvic lymphadenectomy in 10 patients].

From November 1991 through January 1993, we performed laparoscopic lymphadenectomy on 10 patients. These patients were aged 54 to 77 years. All laparoscopic procedures were performed under general anesthesia. We dissected obturator lymph nodes on bilateral side. Total operation time ranged from 127 to 325 minutes. We could excise 3 to 9 lymph nodes on right side and 0 to 10 lymph nodes on left side. Blood loss was 180 ml in one patient, but minimal in the remaining 9 patients. Ureteral injury occurred during laparoscopic procedure in one patient. This injury could be managed with laparoscopic and cystoscopic procedure. Postoperatively complications were observed in 5 procedures, which consisted of subcutaneous emphysema in 2 procedures, fever (over 38 degrees C) in 2, shoulder and arm pain in 1, ileus in 1. The patient with ileus complained of abdominal fullness but he was able to ingest. All patients resumed their preoperative activity by postoperative day 3 to 5. We believe that this procedure was safe and useful for decision making in the management of our patients. We need further study on indications and techniques for this procedure.

Aged↗
PubMed1993

Enhanced proliferative potential in culture of cells from p53-deficient mice.

Normal somatic cells are endowed with limited doubling potential in culture, and the process of immortalization is an inevitable step in neoplastic transformation of the cells. To examine the roles of p53 in this process, the cells of p53-deficient mice were examined for doubling potential. Fibroblast-like cells from a variety of tissues of these mice proliferated continuously without showing aging or crisis. The aneuploid cells overcome the population with passage, but cloning experiment indicated that chromosomal changes were not essential to this process. The enhanced proliferative potential in culture of cells from the p53-deficient mice was also observed in epithelial cells of lens, mammary glands and seminal vesicles and in neural precursor cells. Proliferation of bone marrow cells in response to stem cell factor was enhanced in long term culture, but not in in vitro colony assay; no permanent cell lines could be obtained. No effects of p53-deficiency were found in proliferation of cardiac muscle cells or hepatocytes.

Aneuploidy↗
PubMed1993

[Clinical evaluation of a new kit (IMX PA Dainapack) for detection of serum prostate specific antigen].

A study of the clinical utility of the IMx PA Dainapack, a new kit for detection of serum prostate specific antigen (PSA) by a fully automated enzyme immunoassay (EIA) system, was conducted. Results concerning reproducibility, dilution linearity and sensitivity were good. The excellent assay performance of this kit, particularly in terms of its high sensitivity (0.1 ng/ml), was confirmed. The upper limit of normal was determined to be 4.0 ng/ml from the mean +/- 3 S.D. (3.79 ng/ml) in healthy male controls (n = 244). Using 4.0 ng/ml as the upper limit of normal, 6 of 244 healthy male controls (2%) were positive. In various urinary diseases, 173 of 192 prostatic cancer (90%) and 46 of 112 benign prostatic hypertrophy (BPH) (41%) cases were positive. In prostatic cancer, the positive rates increased with the advance in clinical stage and in stage A the positive rate was especially high (8 of 12 (67%) were positive). On the other hand, using the BPH group as a negative control, the maximum accuracy rate for prostatic cancer had a cut-off value of 8.0 ng/ml. Thus, 8.0 ng/ml is an appropriate cut-off value differentiating prostatic cancer from BPH while 4.0 ng/ml is the cut-off value between the normal group and those with prostatic cancer (including stage A) and BPH. In the follow-up patients with prostatic cancer, serum PSA values measured by this kit reflected the effectiveness of treatment. The correlations between values obtained with the IMx PA Dainapack and 6 current kits were good (r = 0.93 to 0.99) but the values differed with the kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Age and sex dependent distribution pattern and normal range of blood cell parameters obtained by automated blood cell analyzer].

Distribution and normal value of 23 blood cell parameters in healthy 2509 males and 1658 females (20-69 year of age) who are the visitors of our health examination clinic or workers of the hospital were studied. These parameters were obtained by automated cell analyzer (Sysmex NE-8000, Toa Med. Electronics). Distribution pattern and normal range of 23 parameters were studied in different groups of the sex and the age (decade). Distribution of the parameters in each groups was classified into 5 patterns such as Gaussian (G), log-Gaussian (L), skewed toward lower values (P1), skewed toward higher values with shorter tail than of log-Gaussian (P2), skewed toward higher values with longer tail than of log-Gaussian (P3). Normal range of parameters in each groups was calculated by mean +/- 1.96SD of normal distribution curve obtained by power transformation procedure in L, P1, P2 and P3 distribution. Parameters concerning leukocytes and platelets showed rarely G distribution in each groups. Significant sex difference was observed in leukocyte count (male > female, p < 0.001) and platelet count (female > male, p < 0.01) in each age group. Normal values of newly analysed parameters as volume distribution curve of erythrocytes and platelets, mean platelet volume and large platelet ratio were established.

Adult↗
PubMed1993

Trabeculotomy ab externo: an alternative treatment in adult patients with primary open-angle glaucoma.

Seventy-nine adult patients with primary open-angle glaucoma (POAG) were randomly assigned to treatment by modified trabeculotomy ab externo (TAB) (n = 44) and by trabeculectomy with adjunctive mitomycin C (TMC) (n = 35), and the postoperative outcomes achieved with these two techniques were compared. With TAB, the probability of successful intraocular pressure control 1 year postoperatively was .8644; with TMC, .8432; the difference is not significant (P = .7956). However, postoperative complications such as corneal epithelial damage, bleb leaks, hypotony, flat anterior chamber, and serous choroidal detachment were significantly less frequent in the TAB group. Largely because of this latter consideration, in selected cases, TAB may be a viable alternative to TMC.

Adult↗
PubMed1993

Pro-opiomelanocortin messenger RNA levels in anterior pituitaries of female Wistar fatty rats.

We have studied pro-opiomelanocortin (POMC) gene expression by quantifying the POMC mRNA contents in anterior pituitaries of female Wistar fatty rats, a strain obtained by transfer of the fa gene in Zucker rat to Wistar Kyoto rat, in an attempt to understand the role of ACTH synthesis in altered ACTH and corticosterone secretion in these rats. Five- and 12-week-old female Wistar fatty rats and their lean littermates were examined. Plasma ACTH levels were significantly higher in fatty rats than in lean rats (5 weeks: 114.5 +/- 17.5 pg/ml vs. 54.3 +/- 12.4 pg/ml; 12 weeks: 83.8 +/- 12.3 pg/ml vs. 51.7 +/- 6.8 pg/ml; P < 0.01). There was no significant difference between 5-week-old fatty rats and lean rats in POMC mRNA contents nor in POMC/beta-actin ratios in anterior pituitaries. Twelve-week-old fatty rats, however, had significantly higher POMC mRNA contents and also higher POMC/beta-actin ratios in anterior pituitaries than those in lean littermates (P < 0.01, approximately three-fold difference between lean and obese rats). These data suggest that the difference in POMC mRNA contents between lean and obese rats becomes apparent as they grow and develop obesity and the elevated POMC mRNA levels are at least partly responsible for the increased ACTH secretion in 12-week-old fatty rats.

Adrenocorticotropic Hormone↗
PubMed1993

Activation of c-mos oncogene by integration of an endogenous long terminal repeat element during transfection of genomic DNA from mouse skin tumor cells.

An activated c-mos oncogene was identified in a transformed clone of golden hamster embryo cells transfected with DNA extracted from cells cultured from a UV-induced mouse skin tumor. Southern blot hybridization with a v-mos oncogene probe showed that the mos oncogene was amplified in the primary and secondary transformed cells but not in the original tumor cells. Expression of the mos oncogene was very high in the primary and secondary transformants, but mos mRNA was undetectable in the original tumor cells. A genomic DNA fragment containing the activated mos oncogene was cloned and sequenced. The upstream mouse sequence of the mos oncogene, which functions as the transcription terminator, was lost and replaced by a mouse endogenous long terminal repeat (LTR) element that provides the promoter sequence, resulting in high expression of the gene. The rearrangement apparently occurred during transfection, since the polymerase chain reaction (PCR) product encompassing the junction region was present in the primary and secondary transformants but not in the original tumor cells. The LTR element is likely to have been amplified during the skin tumor development caused by UV irradiation. Southern blot hybridization showed that the copy number of LTR in the tumor cells was significantly higher than that in normal skin cells. The amplification of the LTR in the cells may have increased the chance of recombination between the LTR and c-mos gene during the DNA transfection.

Animals↗
PubMed1992

Activation of phospholipases in platelets by polyclonal antibodies against a surface membrane protein.

In a previous paper we demonstrated using immunochemical techniques that propolypeptide of von Willebrand factor was present on the surface of resting platelets. In the present paper we show that polyclonal antibodies against propolypeptide of von Willebrand factor induce activation of phospholipase(s) in platelets and lead to platelet aggregation. The antibody-stimulation of platelets induced the synthesis of thromboxane A2 (TXA2). Furthermore, the aggregation was inhibited by aspirin and an antagonist of TXA2. Aspirin inhibited not only the aggregation but also the activation of arachidonic acid liberation from phospholipids, but the effect of aspirin on arachidonic acid liberation was cancelled by the combined effect of the antibodies and a TXA2 mimetic agonist, which itself did not activate arachidonic acid liberation. The antibody-induced activation of arachidonic acid liberation and the aggregation were blocked by cytochalasin B. All these results obtained with antibodies were quite similar to the results obtained with collagen.

Antibodies↗
PubMed1992

Immunoreactive corticotropin-releasing hormone levels in the hypothalamus of female Wistar fatty rats.

We have studied immunoreactive corticotropin-releasing hormone (CRH) levels in the hypothalamus of female Wistar fatty rats, a strain with the fa gene transferred from the Zucker rat to the Wistar Kyoto rat, in an attempt to understand the role of CRH in the development of obesity. A study was conducted with 5-week- and 12-week-old female Wistar fatty rats and lean littermates. There was no significant difference in hypothalamic CRH levels between lean and obese rats at the age of 5 weeks (1887 +/- 99.6 vs. 1767 +/- 124 pg/tissue; mean +/- S.E.M.). Hypothalamic CRH immunoreactivities, however, were significantly lower in 12-week-old obese rats (2361 +/- 132 pg/tissue) than those in lean littermates (2992 +/- 118 pg/tissue; P less than 0.05). The difference of CRH contents between the lean and obese group becomes apparent as they grow up and develop obesity.

Aging↗
PubMed1992

Expression of M-CSF receptor encoded by c-fms on smooth muscle cells derived from arteriosclerotic lesion.

Vascular smooth muscle cells in atherosclerotic lesions are phenotypically different from those in the normal arterial wall, and no expression of macrophage colony stimulating factor (M-CSF) receptor encoded by the proto-oncogene c-fms has been demonstrated in normal smooth muscle cells. In the present study, we demonstrated expression of c-fms and high affinity binding of M-CSF in smooth muscle cells isolated from an experimental rabbit model of arteriosclerosis (intimal smooth muscle cells), while no expression of c-fms was shown in medial smooth muscle cells. In the immunocytochemical analysis, both types of smooth muscle cells similarly reacted with an antibody specific to muscle cells (HHF 35) but did not react with an antibody specific to rabbit macrophages (RAM 11). In intimal smooth muscle cells, when cells were incubated with acetylated low density lipoproteins (LDL), the binding of acetylated LDL and foam cell formation were observed. In response to M-CSF, tyrosine-phosphorylation, as analyzed by the detection of anti-phosphotyrosine-reactive proteins, and an increased rate of cell proliferation were observed in intimal smooth muscle cells. These results indicated that intimal smooth muscle cells have the characteristics of monocyte-macrophages such as the expression of c-fms, which may be related to their proliferation and phenotypic conversion into foam cells in atheromatous lesions.

Animals↗