Shohei Kagawa

Long-term effect of 2-deoxy-2-fluoroglucose on maintenance in culture of the neonatal B cell of rat.

Abstract This report describes a beneficial role for 2-deoxy-2-fluoroglucose(2-dfg) in promoting survival of neonatal B cells of the rat. Culturing of islets in medium with 5.5 mM glucose abolished the glucose responsiveness of B cells after 7 days of culture. By contrast, the 2-dfg supplemented culture maintained glucose-induced insulin release, and the recovery of insulin in B cells at day 7 at levels 4 to 7-fold higher than at day 0. Slightly enhanced insulin biosynthesis was observed in those B cells. In addition, a selective deletion of fibroblasts was caused by the addition of the fluoroglucose.

The Importance of Disinfection Therapy Using Povidone-Iodine Solution in Atopic Dermatitis

The combination of the local disinfection therapy against Staphylococcus aureus with the conventional therapy for atopic dermatitis has been widely used, and the improvement in skin lesions has been reported to be associated with a remarkable decrease in IgE levels and reagin antibody titers. We have already reported that affected organs were not only the skin but also the gastrointestinal tract in a case with atopic dermatitis. In the present study, the duodenal tissues were examined by biopsy in 32 patients with atopic dermatitis, and mild or chronic duodenitis was observed in all samples. Toxins were examined by PCR from 180 Staphylococcus aureus strains obtained from our patients. The detection rate of toxins was 82.8%. In many patients, antitoxin IgE antibody titers corresponding to their types of toxin and IgE levels were decreased in a parallel manner as time passed. We found 1 patient who complained of paresthesia in all four limbs, and her neurological and radiological examinations showed moderate cervical spondylosis. Neurological examinations revealed some abnormalities in 43 out of 50 patients with atopic dermatitis, such as hyperreflexia of the legs. Cervical MRI was carried out randomly and showed abnormal findings in 21 of 25 patients, in whom 18 duodenal tissues were examined by biopsies.

Elevation of plasma triglyceride levels due to 2-deoxy-D-glucose in conscious rats

Hypertriglyceridemia due to 2-deoxy-D-glucose administration was observed in conscious rats. Plasma triglyceride levels were elevated dose-dependently 2 or 3 hrs after administration of 2-deoxy-D-glucose (5-40 mg/100 g body weight). Prior to the rises in triglyceride, plasma epinephrine levels were elevated rapidly, whereas plasma insulin was not increased depspite continuous hyperglycemia. Elevation of plasma triglyceride was suppressed by addition of phentolamine, whereby insulin release was remarkably enhanced. Plasma lipoprotein lipase release by heparin infusion was significantly suppressed 2 hr after 2-deoxy-D-glucose administration. In conclusion, it is suggested that the hypertriglyceridemic effect of 2-deoxy-D-glucose may be mediated by decreased clearance of endogeneous lipoprotein particles (mostly chylomicrons) attributable to a lowered lipoprotein lipase activity.

EFFECT OF 2-DEOXY-D-GLUCOSE ON MAINTENANCE IN CULTURE OF NEONATAL B CELL OF RAT

SummaryThe effect of 2-deoxy-d-glucose on maintenance in culture of B cells of the neonatal rat was examined by supplementation of Medium 199 containing 5.5 mM glucose with 1 mM 2-deoxy-d-glucose. Islets maintained in medium with 5.5 mM glucose (basal medium) for 7 d underwent remarkable decreases in glucose sensitivity, and the levels of insulin in the medium dropped. By contrast, addition of 2-deoxy-d-glucose promoted a higher insulin content in medium and an increase in the glucose-induced insulin release and biosynthesis. Moreover, the addition of the deoxysugar caused a selective deletion of fibroblasts and prevented the deterioration of islet cells in basal medium, yielding clusters mostly consisting of islet cells at the end of culture.

Rapid Single-Base Mismatch Detection in Genotyping for Phenylketonuria

Phenylketonuria (PKU) is a metabolic disorder that results from a deficiency of hepatic phenylalanine hydroxylase (PAH). Identification of the PKU genotype is useful for predicting clinical PKU phenotype. More than 400 mutations resulting in PAH deficiency have been reported worldwide. We used a genedetecting instrument to identify the nine prevalent Japanese mutations in the PAH gene among 31 PKU patients as a preliminary study. This instrument can automatically detect mutations through the use of allele-specific oligonucleotide (ASO) capture probes, and gave results comparable to those of sequencing studies. Each country has uniquely prevalent and specific mutations causing PKU, and less than 50 types of such mutations are generally present in each country. Early genotyping of PKU makes it possible to identify the phenotype and select the optimal therapy for the disease. For early genotyping, the instrumental method described here shortens the time required for genotyping based on mRNA and/or genomic DNA of PKU parents.

Development and function of B cells in monolayer islet cells of 3-week-old rat

Monolayer cultures of pancreatic B cells of 3-week-old rats were kept for 7 days in medium with 5.5 mM glucose plus 1 mM 2-deoxy-2-fluoroglucose or for 4 days in medium with 5.5 mM glucose alone, following exposure for 3 days to a medium with 5.5 mM glucose plus 5 microM iodoacetic acid. Addition of the deoxyglucose or iodoacetic acid caused a selective deletion of fibroblasts, yielding large clusters that consisted mostly of islet cells. At the early stage of culture in medium with 16.7 mM glucose (day 4), the response of B cells to 16.7 mM glucose included only a small rise in insulin secreted during the first and second phases, and that to 10 mM of leucine and 2-ketoisocaproate was monophasic. After culturing for 7 days, these three secretagogues markedly stimulated insulin secretion by B cells cultured in both media, with a significant rise in secondary phase secretion. However, quantitative relationships differed. Thus, the response (total insulin secreted during a 30-min stimulation) of B cells in 2-deoxy-2-fluoroglucose to glucose was 155%, to leucine 185% and 2-ketoisocaproate 126% of that of cells exposed to iodoacetic acid. In conclusion, the present results suggest that B cells of 3-week-old rat may be immature, and that medium containing 2-deoxy-2-fluoroglucose is beneficial to continued maturation of the response in vitro.

新生児ラット膵単層培養B細胞機能の成熟に及ぼす2-deoxy-2-fluoroglucoseの効果

Monolayer islet cells prepared from neonatal rat pancreases were cultured in media with 5.5 mM glucose alone or supplemented with 1 mM 2-deoxy-2-fluoroglucose for a total of 7 days. The recovery of insulin in the cells and media, and the insulin secretory responses to four secretagogues were determined on several occasions. Under culture conditions with a basal medium containing 5.5 mM glucose, the responses to insulin secretagogues tested were abolished after 7 days of culture. In contrast, the addition of 2-deoxy-2-fluoroglucose maintained the insulin secretory responses to glucose (2.8 approximately 33.4 mM), leucine (2.5 approximately 10 mM) and 2-ketoisocaproate (2.5 approximately 10 mM) at levels several times higher than at day 0. Moreover, in these monolayer islet cells the rates of 0.62 mM [U-14C]glutamine oxidation were significantly increased by leucine or 2-ketoisocaproate at 10 mM. From these results, it is suggested that a series of metabolic adaptations in response to change in nutritional status (possibly attributable to the action of 2-deoxy-2-fluoroglucose as an inhibitor of glycolysis) may facilitate the metabolism of amino acids in B cells. Such an activation may be associated with the survival and maturation of neonatal B cells in vitro.