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Biomedical subjects

S Sumida

Publications and source records attributed to S Sumida.

18 recordsLinked to original sources
PubMed1992

Phosphorylation of the retinoblastoma protein by cdk2.

The retinoblastoma gene product (the RB protein) is phosphorylated in a cell cycle-dependent manner and this modification is believed to be important for cells to progress through the cell cycle. We found that purified cdk2 (cyclin-dependent kinase/cell division kinase 2) can phosphorylate the RB protein in vitro at the sites phosphorylated in the cell. The timing of activation of cdk2 in the cell cycle was similar to that of the onset of phosphorylation of the RB protein. The kinase coprecipitated with the RB protein also exhibited a similar substrate specificity to cdk2 and a similar time course of activation during the cell cycle. We further showed that cdk2 formed a complex with the RB protein in vitro and that its formation was not competitively inhibited by the simian virus 40 large T antigen. These observations suggest that cdk2 or a cdk2-related protein is involved in the cell cycle-dependent phosphorylation of the RB protein.

CDC2-CDC28 Kinases↗
PubMed1992

Phosphorylation of the anti-oncogene products and control of the cell cycle.

To investigate the function of the RB protein, we have studied cellular RB binding proteins and protein kinases responsible for phosphorylation of the RB protein. (1) We purified a cellular RB-associated protein p56 which competes with SV40 large T antigen for binding to the RB protein. (2) In another experiment, we screened expression libraries of U937 monocytic leukemia cell line by West-Western method and obtained two cDNA clones that encode RB binding proteins. (3) The RB protein was found to be phosphorylated by cdk2 and MAP kinase in vitro. Most of the sites phosphorylated in vitro are the same as those phosphorylated in vivo and the time course of activation of cdk2 in the cell cycle were similar to that of phosphorylation of the RB protein.

Cell Cycle↗
PubMed1991

Fukuyama type congenital progressive muscular dystrophy.

Clincopathological features of Fukuyama type congenital muscular dystrophy (FCMD), a combination of brain malformation and muscular dystrophy with facial muscle and CNS involvement and high prevalence in Japan, are reviewed. Evidence of progressive dystrophy, negative correlations between muscle enzyme levels and age and CT numbers of muscle and age, are presented. Skeletal muscle histopathology is reviewed. Febrile illness-induced transient exacerbation of muscle weakness is reported. Characteristic brain malformations, e.g. micropolygyria, other dysgenesis, are reviewed. Their severity correlated with maximal mental and motor function. The etiology and significance of low density areas (LDA) in white matter on CT, possibly reflecting delayed or abnormal myelination, and ventricular dilatation are discussed. Spontaneous LDA improvement makes hydrocephaly unlikely. Ophthalmological differential diagnosis from Santavouri disease and Walker-Warburg syndrome, characterized by visual disturbance/glaucoma and microphthalmia/anterior chamber defects, respectively, is discussed. A single defective gene, manifesting as a metabolic error, may produce CNS and ocular defects as well as muscle degeneration in FCMD.

Brain↗
PubMed1991

Physiologic status at 1-year follow-up of obese women engaged in a supervised conditioning program.

A follow-up study was conducted to re-evaluate a group of obese middle-aged women (n = 13), eight of whom had completed an 18-wk supervised (3 d/wk) plus unsupervised (2 d/wk) conditioning intervention program (at least 90 min per day) as the exercise plus diet group; while five of the remainder served as the control group. Each session had included a 25- to 45-min jog/run at intensities between the heart rate (HR) corresponding to lactate threshold (LT) and that slightly above the HR @ LT. During 1 year following the program, the women participated in self-controlled training such as running, aerobic dancing, or jazz dancing 2.6 +/- 1.1 d/wk. Dietary intake averaged approximately 1736 +/- 152 kcal/d at the pre-treatment, 1404 +/- 124 kcal/d at the post-treatment, and 1645 +/- 147 kcal/d 1 year after the post-treatment. Interestingly however, oxygen uptake corresponding to LT (VO2 @ LT), maximal oxygen uptake (VO2max), weight, systolic blood pressure, and the ratio of high-density lipoprotein cholesterol to total cholesterol (HDLC/TC) observed 1 year after the post-treatment were significantly different from the original pre-treatment and/or mid-treatment values. For instance, the significant 42% increase (14.7 +/- 2.4----21.3 +/- 4.2 ml/kg/min) in VO2 @ LT and 18% increase (0.284 +/- 0.106----0.335 +/- 0.093) in HDLC/TC from the pre-test to post-test were maintained throughout the 1-year follow-up period, suggesting no detrimental effect either on a cardiorespiratory fitness factor or on an anti-atherogenic factor. These findings indicate that physiologic status of obese middle-aged women engaged in a conditioning intervention program may not regress to pre-treatment status for at least one year after completion; provided they continue to participate in a 2.6-d/wk self-controlled training program with dietary intake of 1600-1700 kcal/d. Another interesting finding was that significant relationships existed between individual changes (delta) in training frequency and individual changes (delta) in physiologic variables (i.e., delta VO2max, delta VO2 @ LT, delta WT, delta fat, and delta HDLC/TC) during the follow-up study. It is concluded that, although the improved physiologic status of obese women can be maintained fairly well during 1 year following the conditioning program; continuation of training (3 d/wk or more) should be critical, either supervised or self-controlled, for successful maintenance of lost weight (8.2 +/- 2.9 kg) and improved fitness.

Adult↗
PubMed1991

T-lymphocyte subsets in human non-insulin-dependent diabetes mellitus (type II) studied by two-color flow cytometry.

We report the immunological characteristics of human peripheral T lymphocytes and behavior of PHA-stimulated lymphocytes in Type II diabetes mellitus, investigated two-color flow cytometry. The subsets of Leu11+Leu7+, Leu11-Leu7+ and Leu7+Leu2+ were decreased significantly in peripheral Natural Killer cells. After PHA stimulation the T-cell subsets demonstrated a decrease in the inducer subset and in the cytotoxic subset. The helper cell subset showed a negative regression with HbA1. The cytotoxic cell subset showed a positive regression with HbA1 and also FBS. The CD4/CD8 ratio, and the IL2+Leu2+ subset, showed a negative regressions with HbA1, and the diabetic duration, respectively. Thus, these results are a further demonstration of changes in lymphocytes in NIDDM.

Adult↗
PubMed1990

Bone allografts after segmental resection of tumours.

Massive cryo-preserved bone allografts were implanted in 17 patients after segmental resection, 10 for malignant and 7 for benign bone tumours. A segmental graft alone was used in 6 cases, a bone graft with an arthrodesis in 8, and a combination of graft and prosthesis in 1. The tumours were resected widely; the average length of graft was 6.4 cm in benign tumours and 11 cm in malignant tumours. Chemotherapy was given for one year after operation. There were 2 local recurrences, one severe infection, sloughing of the wound in 2, graft absorption in 3 and breakage of metal in 2. Follow up was from 14 months to 12 years. Bone healing was assessed by radiography in 13 cases. All grafted bone in patients receiving chemotherapy failed to heal primarily, as did 3 of the grafts for benign tumours. Secondary rigid fixation and an additional autogenous graft resulted in healing of the bone junction within a year.

Adolescent↗
PubMed1990

[Skeletal muscle CT scan and ultrasound imaging in two siblings with central core disease].

The computed tomography (CT) and ultrasound (US) imaging studies were performed on skeletal muscles of two siblings (5-year-old boy and 10-year-old girl) with central core disease. The appearance of low-density areas in muscles was remarkable at the levels of the 3rd lumbar vertebra (L3), the midthigh and the thickest part of legs. The muscles at the levels of L3 and thigh were more severely affected than those of legs. Especially, paravertebral muscles, m. vastus, m. sartorius, m. gracilis tended to be more severely affected. The muscles of the legs except m. soleus were well preserved. US imaging of the thigh revealed a marked increase of echogenicity of rectus muscle as well as opaque, indistinct changes of fascia and bone. In contrast, the CT finding of the rectus muscle was relatively well preserved.

Child↗
PubMed1989

Tocopheroxyl radical persistence and tocopherol consumption in liposomes and in vitamin E-enriched rat liver mitochondria and microsomes.

Substantial loading of rat liver mitochondrial and microsomal membranes with D-alpha-tocopherol was achieved by dietary supplementation with no adverse effects of this loading being apparent, e.g. on treadmill exercise endurance. The tocopheroxyl radical was readily detected by ESR in the enriched microsomes and mitochondria. Continuous enzymatic oxidation with horseradish peroxidase and a hydrophilic phenol, to favor selective oxidation of tocopherol without the involvement of lipid peroxidation, allowed the tocopheroxyl radical to be observed for up to 1 h in liposomes of dioleoylphosphatidylcholine and for about 15 min in the subcellular membranes. Total alpha-tocopherol decreased throughout this period, but a significant residual fraction remained after all the ESR signal of tocopheroxyl had disappeared. Decay kinetics of the tocopheroxyl radical ESR signal produced by a burst of intense UV irradiation consisted of a rapid initial phase and a slower exponential decay. A more narrow and more persistent ESR signal, not yet chemically identified, was observed after the tocopheroxyl radical had disappeared under prolonged oxidation. Ascorbic acid prevented formation of the tocopheroxyl radical until the ascorbyl radical ESR signal had decayed, whereas uric acid, up to saturating concentration in phosphate buffer, had no effect.

Animals↗
PubMed1989

Exercise-induced lipid peroxidation and leakage of enzymes before and after vitamin E supplementation.

1. The purpose of this study was to investigate the effects of vitamin E on serum levels of malondialdehyde following the acute exhaustive exercise in human, and to determine whether the magnitude of leakage of enzyme would be affected by vitamin E supplementation. 2. Increase of malondialdehyde after exercise before vitamin E supplementation was slight (but statistically significant), however after supplementation with vitamin E, malondialdehyde level after exercise was significantly decreased. 3. Leakage of enzyme was significantly increased after exercise before vitamin E supplementation, but it was lower following exercise after vitamin E supplementation. 4. Lipid peroxidation following a bout of acute heavy exercise can be inhibited by vitamin E supplementation.

Adult↗
PubMed1989

A case of interstitial pneumonia antedating rheumatoid arthritis.

We describe a case report of an interstitial pneumonia in which pulmonary involvement of the both lower lobes mimicked idiopathic interstitial pneumonia (IIP) or bronchiolitis obliterans organizing pneumonia (BOOP). Its appearance antedated clinically apparent rheumatoid arthritis by one month and a half.

Adult↗
PubMed1978

Vantage point.

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Labor Unions↗
PubMed1977

Lymphomatoid granulomatosis: association with retroperitoneal fibrosis and evidence of impaired cell-mediated immunity.

Lymphomatoid granulomatosis is a non-neoplastic lymphoreticular disorder that usually presents as primary lung disease. A case of lymphomatoid granulomatosis associated with retroperitoneal fibrosis is reported. The retroperitoneal fibrous tissue contained the same variegated lymphoreticular infiltrate that formed the lung tumor, suggesting that the disease may have begun in the retroperitoneum. An extensive immunologic evaluation of the patient revealed impaired cell-mediated immunity.

Humans↗