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Biomedical subjects

T Noguchi

Publications and source records attributed to T Noguchi.

At least 667 records · Page 37Linked to original sources

Characterization of insulin receptors in primary cultures of quail (Coturnix coturnix japonica) oviduct cells. The level of insulin receptor is regulated by steroid and peptide hormones.

1. We have characterized the insulin receptor in primary cultured quail oviduct cells and examined the hormonal regulation of its level. 2. We have also shown the recycling pathway of insulin receptors in the cultured cells using specific inhibitors (tunicamycin, chloroquine, monensin, and brefeldin A). 3. Our data suggest that glucocorticoids play important physiological roles in egg-white protein synthesis through increasing the number of insulin receptors and insulin through enhancing the transport of amino acids.

Aminoisobutyric Acids↗

Correlation between the urinary excretion of acid-soluble peptides, fractional synthesis rate of whole body proteins, and plasma immunoreactive insulin-like growth factor-1/somatomedin C concentration in the rat.

The relations between the urinary excretion of acid-soluble peptide (ASP)-form amino acids, the rate of whole body protein synthesis and plasma immunoreactive insulin-like growth factor-1/somatomedin C concentration were investigated in rats. The urinary ASP-form leucine plus valine excretion correlated well with the rate of whole body protein synthesis and with the plasma immunoreactive insulin-like growth factor-1 concentration. The results provide further evidence for the hypothesis that urinary excretion of ASP is an excellent index of the status of protein metabolism in animals.

Animals↗

Regulation of L-type pyruvate kinase gene expression by dietary fructose in normal and diabetic rats.

Previous studies have shown that dietary fructose stimulates expression of the L-type pyruvate kinase gene mainly at the post-transcriptional level in diabetic liver, and that this effect may be mediated by a metabolite common to both fructose and glycerol. In the present work, we carried out further studies on the mechanism of fructose induction of L-type isozyme mRNA in the liver, kidney and small intestine of rats. The L-type isozyme mRNA in the kidney of normal and diabetic rats was increased by dietary fructose, the time course of the increase being similar to that observed in the small intestine and liver. The mRNA was not induced in the kidney by dietary glucose or insulin. Glycerol was also a potent inducer of the mRNA in the kidney and liver, but not in the small intestine. These results show that fructose and glycerol induced increase in the mRNA only in organs in which they were metabolized, and thus support the metabolite hypothesis. No other carbohydrates tested increased the level of mRNA in these tissues, except glucose, which increased the level in the small intestine. Thus a molecule that increase the mRNA level may accumulate significantly during metabolism of only certain carbohydrates. Dietary fructose or glycerol slightly stimulated transcription of the gene for the L-type isozyme in diabetic liver, and also in normal and diabetic kidney, but the magnitudes of increase were much lower than those of the mRNA, confirming our previous findings described above. On the other hand, dietary fructose caused marked stimulation of gene transcription in normal rat liver, although the magnitude of its induction of the mRNA was similar to that in diabetic liver. Insulin treatment of fructose-fed diabetic rats also caused a marked increase in the gene transcription without any concomitant change in the mRNA level. Thus, the mechanism of fructose induction of the L-type pyruvate kinase in diabetic liver, which is similar to that found in the kidney, is different from that in normal liver, and this difference is attributable to the difference in the level of insulin.

Animals↗

Resonance Raman studies on the structure of bacteriochlorophyll c in chlorosomes from Chloroflexus aurantiacus.

Resonance Raman spectra of chlorosomes isolated from the thermophilic green photosynthetic bacterium Chloroflexus aurantiacus have been obtained with several excitation wavelengths from 441.6 to 514.5 nm. Resonance Raman spectra of bacteriochlorophyll (BChl) c isolated from C. aurantiacus cells have also been observed. The C=C stretching frequencies of BChl c in the chlorosomes were found to be at 1,556 (strong) and 1,544 (shoulder) cm-1, which correspond to those expected for the 5-coordinated BChl c. The C-9 carbonyl resonance Raman frequency was found at 1,642 cm-1, indicating that this group is either hydrogen-bonded to an Mg-coordinated hydroxyl group or coordinated to the Mg ion.

Bacterial Proteins↗

Regulation of the gene expression of glucokinase and L-type pyruvate kinase in primary cultures of rat hepatocytes by hormones and carbohydrates.

The regulation of the gene expression of two important glycolytic enzymes, glucokinase and L-type pyruvate kinase, by hormones and carbohydrates was studied, in primary cultures of adult rat hepatocytes. Insulin caused time- and dose-dependent increases in the amounts of the mRNAs of the two enzymes in hepatocytes, although glucokinase responded to this hormone faster than L-type pyruvate kinase. The induction of glucokinase mRNA by insulin did not require the presence of glucose itself, but that of the L-type isozyme was dependent on the glucose concentration. For this effect, fructose and glycerol could partially substitute for glucose, but pyruvate and 2-deoxyglucose, a nonmetabolizable glucose analog, could not. The time course of insulin induction in the presence of fructose, but not of glycerol, was similar to that in the presence of glucose. In the presence of glycerol, the mRNA increased in a diphasic manner: the first increase, which probably reflected the effects of fructose and glycerol in normal liver, reached a maximum after 3 h, whereas the second increase corresponded to the increase in the presence of glucose. These results suggested that some metabolite of glucose was required for the insulin-induced increase in L-type pyruvate kinase mRNA. Cycloheximide inhibited the effects of insulin on the two mRNAs, suggesting that ongoing protein synthesis is required in both cases. The addition of 1-(5-isoquinolinesulfonyl)-2-methylpiperazine, an inhibitor of protein kinase C, also inhibited the effects of insulin. However, phorbol 12-myristate 13-acetate alone did not induce the two mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Kallikrein- and prolactin-producing cells in the rat anterior pituitary are the same.

Kallikrein-positive cells in the anterior pituitary of female rats were identified to be the same as prolactin-producing cells by using an immunoelectron microscopic method. The kallikrein immunoreactivity was localized at the Golgi apparatus, the rough endoplasmic reticulum, and secretory granules, suggesting that kallikrein is synthesized in the prolactin-producing cells and also may be secreted into the blood vessels.

Absorption↗

Significance of elevated serum LDH (lactate dehydrogenase) activity in atopic dermatitis.

Serum lactate dehydrogenase activity (LDH) was elevated in most cases with the severe type of atopic dermatitis (AD). We examined whether LDH correlated specifically with the clinical courses and the severity of AD skin eruptions. Blood eosinophil numbers (Eo), LDH and its isoenzymes, and serum IgE (IgE) levels in eighty patients with AD were measured before and after treatment. In improved groups, Eo and LDH decreased or returned to normal values after treatment. In contrast, both levels increased in patients who worsened after treatment. Thus changes in Eo and LDH correlated well with the clinical picture. However, IgE levels did not correlate with the clinical condition. High LDH levels were detected in the severe type of AD more frequently than in the mild type. A large majority of patients with elevated LDH (higher than 300 IU/l) before treatment had more severe skin eruptions. When the LDH before treatment was within normal limits, the LDH levels in improved patients showed a further decrease. Eo, LDH and IgE were correlated closely with the clinical scores of AD, and the relationship between LDH and clinical score was the highest. Elevations of LDH5 and LDH4 among the LDH isoenzymes were more prominent in the severe type of AD than in the mild type. We concluded that LDH was useful as a marker for evaluating the disease condition and severity of skin eruption of AD.

Adolescent↗

Structure of pollen grains of Tradescantia reflexa with special reference to the generative cell and the ER around it.

A pollen grain in Tradescantia reflexa consists of two cells, the generative and the vegetative cells, the generative cell being surrounded completely by the vegetative cell. The generative cell has many lobes or surface invaginations. A complicated network of rER extends throughout the entire vegetative cytoplasm, forming a system of channels made up by the cisternae of rER. Lipid granules are surrounded by ER. Branches of the rER enter all the concavities of the invaginations and attach to the plasma membranes at the bottoms of the invaginations. In the generative cell, no reserve substances, such as lipids, are seen. There is little ER, mitochondria are few in number, and Golgi bodies seem to be less active within this type of cell. Bundles of microtubules run parallel to the long axis of the generative cell. No microtubules or microfilaments can be detected at or near the bottoms of concavities, either on the generative or the vegetative side. ER is the sole cell element that bears a positional relationship to the invaginations. It appears, therefore, that rER is intimately involved in the shaping of the invaginations. This is the first report that a cell element other than microtubules and microfilaments can be involved in the formation of the outer shape of a cell. The possibility that materials from decomposed lipid droplets are transported through the rER to the generative cell is also discussed.

Cytoskeleton↗

Immunohistochemical localization of kallikrein within the prolactin-producing cells of the rat anterior pituitary gland.

The localization of tissue kallikrein in the pituitary gland of rats was investigated by an immunohistochemical technique using antiserum against rat urinary kallikrein. Kallikrein-positive cells were detected in the anterior lobe of the pituitary of both male and female rats, but were not observed in the posterior lobe of the pituitary in either sex. The kallikrein-positive cells in the anterior pituitary of female rats in oestrus were found to correspond to the prolactin-producing cells, whereas the cells producing GH, LH and ACTH were negative for kallikrein. It is possible, therefore, that the tissue kallikrein may be involved in the production of prolactin and not that of the other anterior pituitary hormones, such as GH, LH, FSH, ACTH and TSH.

Animals↗

A new cDNA clone relating to larger molecular species of rat insulin-like growth factor-I mRNA.

A new cDNA clone for rat IGF-I mRNA was obtained. The cDNA contained a new base sequence as cDNA in the 3' region. The sequence coincided with a part of the sequence reported earlier by Shimatsu and Rotwein in exon 5 of the rat IGF-I gene. The presence of this cDNA proved the previous suggestion to be true that the size heterogeneity of IGF-I mRNA is primarily due to the heterogeneity of the 3'-untranslated region.

Amino Acid Sequence↗

Evidence of introduction by molecular cloning of artificial inverted sequence at the 5' terminus of the sense strand of rat insulin-like growth factor-I cDNA.

A cDNA of insulin-like growth factor (IGF)-I mRNA was obtained from a rat liver cDNA library. This cDNA contained a 5' terminal sequence of 48 base pairs complementary to a sequence in the 3' terminal region (an inverted repeat sequence) except for one nucleotide insertion in the 3' region. Base sequence analysis of this cDNA, northern blot analysis of rat liver mRNA using a probe specific to 5' region of cDNA, base sequence studies of the 5' upstream region of a clone of the rat IGF-I gene, and some other studies suggested strongly that the inverted repeat sequence of the IGF-I cDNA used was introduced artificially during preparation of the cDNA library.

Amino Acid Sequence↗

Vital root resection with advanced periodontitis--case reports.

Furca of multi-rooted teeth are sometimes affected by advanced periodontitis and supporting tissue is almost lost around one of two or two of three roots, while the remaining root or roots are supported by a relatively intact periodontium. In these situations, the procedure of root resection has usually been carried out. Though the necessity of prior or simultaneous endodontic treatment will be considered concomitantly, it is not clear the good periodontal results can be obtained in such cases by these endodontic treatments. If the technique of vital root resection should be indicated to these cases, the vitality of the tooth would be retained and the damage would be minimal. The technique of vital root resection and two periodontally successful clinical cases are presented. This technique appears appropriate in cases in which a multi-rooted tooth is afflicted with a hopeless periodontitis involving one or two roots.

Adult↗

[Orthodontic treatment of malocclusion with periodontitis].

Adults with untreated malocclusions suffer from more periodontal disease than if their malocclusion had been corrected orthodontically. What orthodontists can offer in the management of patients with periodontal disease, how they can help the periodontists and the patients, and how the periodontists can help the orthodontist make treatment safe and purposefully are widely discussed. The purpose of this study is, therefore, to discuss how orthodontic patients with severe periodontitis could be treated and what we should do for these patients during the treatment as well as at their initial visit. One case is presented as an example of treatment for malocclusion with sever periodontitis: The patient was a 23 years 8 months female with a chief complaint of protrusion of upper incisors. Since clinical examination revealed severe periodontitis, periodontal treatment was undertaken for one year prior to orthodontic treatment. From these observations, we are conviced of the importance again of the global approach and the team treatment method in treating malocclusions with periodontitis.

Adult↗

Preoperative estimation of surgical risk of hepatectomy in cirrhotic patients.

In order to improve the results of hepatectomy in cirrhotic patients, functional resectability of the liver was evaluated before surgery, in 119 cases of hepatectomy, including 85 cases with cirrhosis, over the last 10 years. Our total risk, measured by multivariate analysis of hepatic function tests, was very useful in selecting the suitable operative method. Functional reserve of the remnant liver and that of per unit volume of the liver evaluated by ICGRmax, were also good indicators for estimating long-term prognosis and liver regeneration following hepatectomy. Furthermore, from our experience with 4 cirrhotic patients who developed disseminated intravascular coagulopathy after hepatectomy, the preoperative evaluation of function in the coagulation-fibrinolysis system was also important for estimating the operative risk of hepatectomy in cirrhotic patients.

Adult↗

[Diuretic effects of aminophylline in patients after cardiac surgery].

Diuretic effects of aminophylline in patients after cardiac surgery were studied by using the local renal thermodilution catheter (Goodman Co. Ltd.). The subjects were 11 patients who underwent cardiac surgery in our hospital. All patients had shown almost normal renal and endocrine function. On the day of operation, we indwelld renal thermodilution catheter into the left renal vein under fluoroscopy. After operation, when the urinary volume decreased below 1 ml.kg-1.hr-1, we administered aminophylline at a rate of 2 ml.kg-1.hr-1. We measured HR, BP, CO, PAP, CVP, renal blood flow, urinary volume, urinary electrolytes, plasma renin activity, angiotensin II, aldosteron, ADH and alpha hANP just before and after infusion of aminophylline. The urine volume, renal blood flow and renal blood flow distribution rate showed significant increases of about 70%, 40% and 35% respectively. But hemodynamic parameters including HR, mean BP and CO increased for 5%, 10% and 8% respectively after administration of aminophylline. In the endocrine system, only angiotensin II increased significantly but aminophylline did not cause any change in endocrine system. The results suggest that diuretic effect of aminophylline is mainly achieved by increasing renal blood flow.

Adult↗