Effect of dietary iron deficiency on mineral levels in tissues of rats

To clarify the influence of iron deficiency on mineral status, the following two synthetic diets were fed to male Wistar rats: a control diet containing 128 micrograms iron/g, and an iron-deficient diet containing 5.9 micrograms iron/g. The rats fed the iron-deficient diet showed pale red conjunctiva and less reactiveness than the rats fed the control diet. The hemoglobin concentration and hematocrit of the rats fed the iron-deficient diet were markedly less than the rats fed the control diet. The changes of mineral concentrations observed in tissues of the rats fed the iron-deficient diet, as compared with the rats fed the control diet, are summarized as follows: . Iron concentrations in blood, brain, lung, heart, liver, spleen, kidney, testis, femoral muscle, and tibia decreased; . Calcium concentrations in blood and liver increased; calcium concentration in lung decreased; . Magnesium concentration in blood increased; . Copper concentrations in blood, liver, spleen and tibia increased; copper concentration in femoral muscle decreased; . Zinc concentration in blood decreased; . Manganese concentrations in brain, heart, kidney, testis, femoral muscle and tibia increased. These results suggest that iron deficiency affects mineral status (iron, calcium, magnesium, copper, zinc, and manganese) in rats.     

The length polymorphism in the 5′ flanking region of the human β-globin gene with denaturing gradient gel electrophoresis in a Japanese population

Summary The ATTTT repeat polymorphism located approximately 1,400 base pairs (bp) upstream from the -globin structural gene was analyzed by denaturing gradient gel electrophoresis (DGGE) of RNA: DNA duplexes. A study of 81 unrelated Japanese from Hiroshima revealed a sequence heteromorphism in this site. The alleles with five and six repeats of the ATTTT unit, which have been reported, were found in polymorphic proportions. Two unreported alleles were also detected, the first, in two persons, characterized by seven repeats and the other, in a single person, having an A-to-G nucleotide substitution in the fifth repeat.     

Combined gas chromatography-chemical ionization mass spectrometry of sphingolipids. I. Glucosyl sphingosine,ceramides and cerebrosides of the spleen in Gaucher's disease

Trimethylsilylated glucosyl sphingosine, ceramides and glucocerebrosides were analysed by combined gas chromatography (GC)-chemical ionization (CI) mass spectrometry. Isobutane, methane and ammonia were used as reactant gases for chemical ionization. Essentially the same fragment ions were detected in the spectra with the different reactant gases.Purified glucocerebrosides isolated from the spleen of a patient with Gaucher's disease were clearly separated into their 8 molecular species by gas chromatography. Three other minor components were detected by spectrometry, and these 11 molecular species of glucocerebrosides from the spleen of the patient with Gaucher's disease have been analysed.The ceramides obtained by periodate oxidation and then alkaline reduction of the glucocerebrosides were also separated into 11 molecular species by GC-CI mass spectrometry.Molecular weight could be determined using the major fragment ion of m/e (M⁺?90) in the spectra of ceramides and cerebrosides. The chemical ionization method is useful for structural analyses and determination of the molecular species of sphingoglycolipids.     

Mastication effort estimated by electromyography for cooked rice of differing water content

The objective of this study was to quantify the mastication effort for cooked rice. We analyzed mastication patterns while normal subjects ate a spoonful of cooked rice that had been prepared by cooking with different amounts of water (1.5, 2.0, 3.0, and 4.0 times the water to rice weight). The rice samples were served with the same weight, same volume and same solid content, and electromyography (EMG) of the masticatory muscles was measured. The texture of the four cooked rice samples was instrumentally analyzed by the two-bite method. The number of chews, masticatory time, and jaw-closing muscle activities per chew evaluated by EMG were higher in the rice sample cooked with least water, which exhibited a high firmness value in the instrumental test. Rice cooked with 4.0 times the amount of water exhibited the longest jaw-opening duration, which was related to the adhesiveness value in the instrumental test. The ratio of jaw-opening muscle activity to the preceding jaw-closing muscle activity was lower for the rice containing least water, this corresponding to the area ratio (balance degree) in the instrumental test. Softer rice containing more water reduced the total mastication effort until swallowing because it required a shorter mastication time. It was not difficult for the softer rice with high density to be ingested in greater weight, decreasing the mastication effort for a certain amount.     

Sulfonylurea as well as elevated glucose levels stimulate reactive oxygen species production in the pancreatic beta-cell line, MIN6-a role of NAD(P)H oxidase in beta-cells

Increased oxidative stress may play a key role in the progressive deterioration of pancreatic beta-cells and the development of diabetes. However, the underlying mechanism is not well understood. Exposure of pancreatic beta-cell line, MIN6 cells, to elevated glucose level for 2h induced an increase in reactive oxygen species (ROS) production, as evaluated by the staining of 2',7'-dichlorofluorescein diacetate. This effect was completely blocked by NAD(P)H oxidase inhibitor (diphenylene iodonium) and protein kinase C (PKC) inhibitor (calphostin C), but not affected by other flavoprotein inhibitors (rotenone, oxypurinol, or l-N-monomethyl arginine). Glibenclamide also stimulated ROS production in a dose-dependent manner. This effect was again blocked by diphenylene iodonium and calphostin C. In conclusion, insulin secretagogues, both glibenclamide and elevated glucose level, stimulated ROS production in beta-cells through a PKC-dependent activation of NAD(P)H oxidase. This mechanism may be a novel therapeutic target for preventing the progression of beta-cell deterioration.     

Increased expression of NAD(P)H oxidase in islets of animal models of Type 2 diabetes and its improvement by an AT1 receptor antagonist

This study was undertaken to reveal the role of NAD(P)H oxidase in increased oxidative stress in islets of Type 2 diabetes. Immunostaining analysis showed that staining intensities of NAD(P)H oxidase components, gp91phox and p22phox, significantly increased in islets of animal models of Type 2 diabetes, OLETF rats (60 weeks of age) and db/db mice (14 weeks of age), compared with age-matched controls, respectively, correlating with increased levels of oxidative stress marker, 8-hydroxy-deoxyguanosine or 4-hydroxy-2-nonenal modified protein. In db/db mice, oral administration of angiotensin II Type 1 receptor antagonist valsartan (5 mg/kg) for 4 weeks significantly attenuated the increased expression of gp91phox and p22phox together with inhibition of oxidative stress and partially restored decreased insulin contents in islets. Angiotensin II-related increased expression of NAD(P)H oxidase may play an important role in increased oxidative stress in islets of Type 2 diabetes. This mechanism may be a novel therapeutic target for preventing beta-cell damage.     

A novel pyrazolone, 4,4-dichloro-1-(2,4-dichlorophenyl)-3-methyl-5-pyrazolone, as a potent catalytic inhibitor of human telomerase

A new derivative of 1-phenyl-3-methyl-5-pyrazolone, 4,4-dichloro-1-(2,4-dichlorophenyl)-3-methyl-5-pyrazolone, named TELIN, was chemically synthesized and identified as a potent inhibitor of human telomerase in the cell-free telomeric repeat amplification protocol. TELIN inhibited telomerase activity at submicromolar level with IC50 of approximately 0.3 microM. Kinetic studies revealed that TELIN does not bind to DNA but to telomerase protein, and the mode of inhibition by this substance was competitive-noncompetitive mixed-type with respect to the TS primer, whereas it was uncompetitive or noncompetitive-uncompetitive mixed-type with respect to the three deoxyribonucleosides. These results demonstrate that TELIN is a specific potent catalytic blocker of telomerase,and is considered to be a valuable substance for medical treatment of cancer and related diseases.     

Increased expression of p62 in expanded polyglutamine-expressing cells and its association with polyglutamine inclusions

Huntington's disease is a progressive neurodegenerative disorder that is associated with a CAG repeat expansion in the gene encoding huntingtin. We found that a 60-kDa protein was increased in Neuro2a cells expressing the N-terminal portion of huntingtin with expanded polyglutamine. We purified this protein, and, using mass spectrometry, identified it as p62, an ubiquitin-associated domain-containing protein. A specific p62 antibody stained the ubiquitylated polyQ inclusions in expanded polyglutamine-expressing cells, as well as in the brain of the huntingtin exon 1 transgenic mice. Furthermore, the level of p62 protein and mRNA was increased in expanded polyglutamine-expressing cells. We also found that p62 formed aggresome-like inclusions when p62 was increased in normal Neuro2a cells by a proteasome inhibitor. Knock-down of p62 does not affect the formation of aggresomes or polyglutamine inclusions, suggesting that p62 is recruited to the aggresome or inclusions secondary to their formation. These results suggest that p62 may play important roles as a responsive protein to a polyglutamine-induced stress rather than as a cross-linker between ubiquitylated proteins.     

No evidence of radiation effect on mutation rates at hypervariable minisatellite loci in the germ cells of atomic bomb survivors

Human minisatellites consist of tandem arrays of short repeat sequences, and some are highly polymorphic in numbers of repeats among individuals. Since these loci mutate much more frequently than coding sequences, they make attractive markers for screening populations for genetic effects of mutagenic agents. Here we report the results of our analysis of mutations at eight hypervariable minisatellite loci in the offspring (61 from exposed families in 60 of which only one parent was exposed, and 58 from unexposed parents) of atomic bomb survivors with mean doses of >1 Sv. We found 44 mutations in paternal alleles and eight mutations in maternal alleles with no indication that the high doses of acutely applied radiation had caused significant genetic effects. Our finding contrasts with those of some other studies in which much lower radiation doses, applied chronically, caused significantly increased mutation rates. Possible reasons for this discrepancy are discussed.