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Biomedical subjects

G Tanaka

Publications and source records attributed to G Tanaka.

At least 55 records · Page 3Linked to original sources
PubMed1991

Analysis of concurrent glucose consumption by the hexose monophosphate shunt, glycolysis, and the polyol pathway in the crystalline lens.

A method based on 13C-NMR spectroscopy is described, in which the metabolism of [13C2]glucose was assessed in intact rat lenses. By analysing the ratio of 13C3/(13C2 + 13C3) lactate, a quantitative measurement of the hexose monophosphate shunt (HMPS) activity could be derived. Similarly, measurements of the time-dependent increase of lactate and sorbitol permitted the determination of the activity of the Embden-Meyerhof pathway and the polyol pathway, respectively. This method offers significant advantages over other biochemical and spectroscopic methods and allows for the first time a direct correlation between the activities of the polyol pathway and the HMPS.

Animals↗
PubMed1990

Design of biologically active, conformationally constrained GnRH antagonists.

The introduction of conformational constraints into a flexible peptide hormone can be exploited to develop models for the conformation required for receptor binding and activity. In this review, we illustrate this approach to analog design using our work on antagonists of gonadotropin-releasing hormone (GnRH). Design of a conformationally constrained, competitive antagonist of GnRH, cyclo[delta 3,4 Pro-D4ClPhe-DTrp-Ser-Tyr-DTrp-NMeLeu-Arg-Pro-bet a Ala] led to the prediction of its bioactive conformation. Template forcing experiments show that this conformation is accessible to other active GnRH analogs. Two-dimensional NMR studies verified the predicted conformation in solution. The predicted binding conformation has recently been used to design two new analogs incorporating side chain-side chain linkages suggested by the conformational model: Ac-delta 3,4Pro-D4FPhe-DTrp-Dap-Tyr-DTrp-Leu-Arg-Asp-Gly- NH2 and Ac-delta 3,4Pro-D4FPhe-DTrp-Dap-Tyr-D2Nal-Leu-Arg-Pro-Asp -NH2. These analogs were synthesized and the one predicted to be most similar to the parent conformation had equivalent potency while the second, designed to refine the conformational hypothesis, was found to exhibit enhanced potency, thus confirming the original binding conformation hypothesis. These compounds and their derivatives now provide a new class of GnRH antagonists possessing both high biological potency and limited conformational flexibility, thus making them ideal for both biophysical and structure-activity studies.

Amino Acid Sequence↗
PubMed1990

Choroid plexus arteriovenous malformation in a full-term neonate. Case report.

A full-term newborn infant with intracranial hemorrhage secondary to an arteriovenous malformation (AVM) of the choroid plexus is presented. Although angiography was not undertaken before surgery, a vascular nodule containing an AVM nidus was found in the hematoma wall. The authors stress that an AVM should be considered as a cause of intracranial hemorrhage and that the hematoma wall be searched thoroughly in neonates without predisposing factors.

Cerebral Hemorrhage↗
PubMed1989

[Japanese reference man 1988-IV. Studies on the weight and size of internal organs of Normal Japanese].

The weight and size of 12 main internal organs of Normal Japanese were measured at the Tokyo Medical Examiners Office, where the autopsies have been carried out on sudden death cases. This report selected, 5,600 cases with little or no pathological body change, from approximately 18,000 total autopsy cases, during the period of 1970-1980. The organs were divided into 23 groups according to age and sex. Mean value and standard deviation were calculated for each group, using a CDC-6600 scientific computer. The data in this report were compared with the data of 1952, when people were in starvation after termination of the World War II. At that time, several organs were decreased in weight by 8% in liver, 15-20% in kidney, heart, spleen and adrenal gland, respectively. However, pituitary gland showed an 18% increase while brain and thyroid showed almost the same value. Other organs measured were lung, liver, pancreas and testis.

Adolescent↗
PubMed1989

Daily intake of 11 elements in relation to reference Japanese man.

Diet samples were collected by a duplicated portion method from 31 locations in Japan in both the summer and winter of 1981. The ashed samples were analyzed with an inductively coupled plasma atomic-emission spectrometer (ICP-AES) for 11 elements: Na, K, P, Ca, Mg, Zn, Mn, Al, Sr, Cu and Ba. Average daily intake was as follows: Na--4.5 g, K--1.9 g, P--0.92 g, Ca--0.56 g, Mg--0.20 g, Zn--7.1 mg, Al--4.0 mg, Mn--3.4 mg, Sr--2.3 mg, Cu--1.3 mg and Ba--0.36 mg. A tendency for higher mineral intakes was found in central Japan. These were the highest in the Chubu area followed by the Kanto and Kinki areas. Lower mineral intakes, below the averages for Japan, were found in western Japan, especially in the Chugoku and Shikoku areas. Daily intake of most elements, except Na, Mn, and Sr, was found to be 40-70% of the levels of Reference Man, which were reported by International Commission on Radiological Protection (ICRP) for the Western Europeans and North Americans. Daily intake of Na, Mn and Sr was almost the same in both cases.

Diet↗
PubMed1988

[Local irritation studies of cefodizime sodium].

Four local irritation studies of cefodizime sodium (THR-221), a new developed cephem-type antibiotics, were carried out with NZW rabbits. 1. In eye irritation test, 25% THR-221 water solution had no irritancy on eye mucosa in rabbits. 2. In single injective intramuscular irritation study, regardless of solvents (water or 0.5% lidocaine), 25% THR-221 solution had irritancy equal to 0.75% acetic acid. But recovery process of the muscle injured with THR-221 was faster and better than with 0.75% acetic acid. 3. In five days injective muscular irritation study, the irritancy of 25% THR-221 water solution on the muscle was milder than that of CTT or CET. Histopathological damage with THR-221, necrosis/degeneration of muscle fibers and edema/hemorrhage in interstitium etc., were well recovered. 4. In vessel irritation study, 10% or more THR-221 water solution had irritancy on ear vessel. THR-221, as same as CTT, caused organized thrombi and inflammation at the surrounding area. The degree of irritation of 20% THR-221 solution was slightly stronger than that of 20% CET, but weaker than that of 20% CTT. 5. In a clinical phase, it is to be desired that THR-221 like as CTT or CET shall be avoided repeated intramuscular or intravenous injections at the same site.

Animals↗
PubMed1983

Actinides concentrations in human tissues.

Fallout 239,240Pu concentrations in some autopsy tissues from the general population in Japan are described. Body burden and relative distribution among tissues of plutonium were obtained by extrapolating using the mass of relevant tissues of the normal Japanese adult. 239,240Pu-to-90Sr body burden ratio was obtained. ICRP models were used to estimate body burden and relative contribution of ingestion intake. Need for data on the intraskeletal distribution of fallout plutonium and more information on gastrointestinal absorption in man was stressed.

Actinoid Series Elements↗
PubMed1983

A 10-year follow-up study of per oral glucose tolerance at annual physical examinations.

In order to elucidate the factors influencing glucose intolerance. 100 g oral glucose tolerance tests serially performed at annual physical examinations over a 10-year period were studied. On the initial examination in 356 subjects, 44.8% were normal and 7.1% diabetic according to the criteria of 100 g OGTT recommended by the Japan Diabetes Society in 1970. For the 10-year follow-up study, the subjects were classified into 2 groups, 30s and 40s, by age at initial examination. The prevalence of obesity in the 30s group the at the 10th year was significantly higher than that of the 40s at the baseline (p less than 0.05). The rate of normal OGTT in the 30s group at the 10th year was significantly lower than that in the 40s group at the baseline (p less than 0.01). When compared with 119 age- and sex-matched employees of a certain bank, the incidence of diabetic OGTT was identical, but obesity was less prevalent in the 40s group from SONY. These results indicate that obesity increases the rate of glucose intolerance in subjects under 40 years of age, but in subjects aged 41 years and over diabetic predisposition appears to play an important role.

Adult↗
PubMed1982

Excluded-volume effect on quasi-elastic light scattering by flexible macromolecules.

First-order perturbation expressions are developed for the first cumulant (initial time derivative) of the dynamic structure factor observable by photon-correlation measurements of the light scattered by flexible chain molecules in solution. A dimensionless coefficient C, which measures the initial departure of the first cumulant from proportionality to the square of the scattering vector, is found to be only slightly altered by excluded-volume effects.

Journal Article↗