A lipidome landscape of aging in mice

Understanding the molecular mechanisms of aging is crucial for enhancing healthy longevity. We conducted untargeted lipidomics across 13 biological samples from mice at various life stages (2, 12, 19 and 24 months) to explore the potential link between aging and lipid metabolism, considering sex (male or female) and microbiome (specific pathogen-free or germ-free) dependencies. By analyzing 2,704 molecules from 109 lipid subclasses, we characterized common and tissue-specific lipidome alterations associated with aging. For example, the levels of bis(monoacylglycero)phosphate containing polyunsaturated fatty acids increased in various organs during aging, whereas the levels of other phospholipids containing saturated and monounsaturated fatty acids decreased. In addition, we discovered age-dependent sulfonolipid accumulation, absent in germ-free mice, correlating with Alistipes abundance determined by 16S ribosomal RNA gene amplicon sequencing. In the male kidney, glycolipids such as galactosylceramides, galabiosylceramides (Gal2Cer), trihexosylceramides (Hex3Cer), and mono- and digalactosyldiacylglycerols were detected, with two lipid classes-Gal2Cer and Hex3Cer-being significantly enriched in aged mice. Integrated analysis of the kidney transcriptome revealed uridine diphosphate galactosyltransferase 8A (UGT8a), alkylglycerone phosphate synthase and fatty acyl-coenzyme A reductase 1 as potential enzymes responsible for the male-specific glycolipid biosynthesis in vivo, which would be relevant to sex dependency in kidney diseases. Inhibiting UGT8 reduced the levels of these glycolipids and the expression of inflammatory cytokines in the kidney. Our study provides a valuable resource for clarifying potential links between lipid metabolism and aging.

[Study on evaluation method of patient dose in diagnostic radiology required for introducing the guidance level: investigation of entrance surface dose of patient using direct measurement by TLD]

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Can heavy charged particles really be regarded as high-LET radiations with respect to their radiobiological actions? I: LETs and fluences of heavy charged particles and associated delta-rays

The structures of the energy transfer of heavy charged particles (HCP) to nm-size targets have been investigated, taking account of delta-ray generation by HCP as well as associated delta-rays. From the microdosimetric viewpoint, the radiobiological effects of HCP have to be analysed in terms of the microdosimetric quantities based on the local energy transfer (LET) to the target, that is the restricted linear energy transfer (Ldelta), and the fluences or the degradation spectra of charged particles including delta-rays. Ldelta of HCP and delta-rays, and the fluences of delta-rays have been calculated for various HCP (H-Ar) with energies 1, 10 and 100 MeV amu(-1). From the results obtained, it is concluded that heavy ions (HI) should be expressed as two-component radiations which are composed of high-Ldelta heavy ion tracks of low fluence and low-Ldelta delta-rays of high fluence; in other words, the currently used expression 'HI are high-LET radiations' is not valid.

Cloning and sequencing of a cDNA encoding alpha-glucosidase from sugar beet

A cDNA encoding sugar beet alpha-glucosidase was cloned from a library constructed from mRNA of suspension-cultured cells. The cDNA, 3056 bp in length, had an open reading frame encoding a polypeptide of 913 amino acid residues with a molecular mass of 102,078 Da, included only one of four regions which were conserved in the alpha-amylase family of enzymes. The deduced amino acid sequence from the analysis of the cDNA contained the sequences of the proteolysis peptides and the active site region peptide of sugar beet alpha-glucosidase. The primary structure indicated relatively high homology in the range of 28.2 to 54.3% to those for other alpha-glucosidases. The highest homology was found in barley alpha-glucosidase.

Chemical modification and amino acid sequence of active site in sugar beet alpha-glucosidase

The modification of amino acid residues in sugar beet alpha-glucosidase with conduritol B epoxide (CBE), an affinity labeling reagent, inactivated the enzyme. The inactivation followed pseudo-first-order kinetics. The enzyme was protected from inactivation by a competitive inhibitor, Tris, and the partially inactivated enzymes showed only the decrease of V values and no change in Km value. An 3H-CBE labeled peptide isolated from the digest of the inactivated enzyme with Lys-C protease was sequenced. The -COO- group of Asp was found to be specifically labeled, implicating that it is a catalytic group of the enzyme. The sequence around the essential Asp was determined to be -DGIWIDMNE-, which showed a high homology with those of other alpha-glucosidases.

Phylogenetic diversity of phytopathogenic mycoplasmalike organisms

By using specific primers, the 16S rRNA genes of Japanese mycoplasmalike organisms (MLOs) were amplified by polymerase chain reactions from MLO-enriched fractions of plants infected with each of six different MLOs. Each of the polymerase chain reaction fragments (length, 1,370 nucleotides) was directly sequenced in both strands by using 17 oligonucleotide primers. A phylogenetic tree constructed by using the sequence data showed that these Japanese MLOs are phylogenetically diverse microorganisms that fall into three groups, group I (onion yellows, tomato yellows, mulberry dwarf, and paulownia witches' broom MLOs), group II (tsuwabuki witches' broom MLO), and group III (rice yellow dwarf MLO). A high level of sequence homology (99%) between the Oenothera hookeri MLO and the severe strain of the western aster yellows MLO on the one hand and group I MLOs on the other indicates that the O. hookeri MLO and the severe strain of the western aster yellows MLO belong to group I and suggests that these MLOs, isolated from two geographically separated locations, descended from a very similar ancestor. Although group I contains phylogenetically identical MLOs, the organisms are transmitted by diverse insect vectors. The three MLO groups are more closely related to Acholeplasma laidlawii than to Mycoplasma gallisepticum. Thus, although MLOs are phylogenetically diverse, they are evolutionarily distant from other mollicutes. These data, together with other information (including phylogenetic relationships, vector specificity, plant-pathogenic properties, and habitat in plant phloem sieve tubes), suggest that MLOs could be classified into at least three phylogenetic groups (groups I through III).

Mycoplasmalike organisms (MLOs) and distinguish them from other MLOs

DNA of 10 lines of rice yellow dwarf (RYD) mycoplasmalike organisms (MLOs) from Japan, the Phillippines, and Thailand hybridized with four probes containing chromosomal and six probes containing extrachromosomal DNA of a Tochigi (Japan) line of RYD MLO. One chromosomal probe (RYD9) and all six extrachromosomal probes hybridized with various other MLOs (sugarcane white leaf, onion yellows, cineraria witches'-broom, Japanese hornwort witches'-broom, water dropwort wiches'-broom, gentian witches'-broom, udo dwarf, tsuwabuki witches'-broom, pelargonium witches's-broom, peach western-X, and pear decline). DNA from the culturable mollicutes Spiroplasma kunkelii, Spiroplasma citri, Mycoplasma hominis, and Mycoplasma orale did not hybridize with RYD MLO probes. The extrachromosomal DNAs hybridizing with the probes showed variations in electrophoretic behavior.

Multiple space-occupying lesions of the spleen in a case of Gaucher's disease

A 50-year-old female patient was admitted because of an enormously enlarged spleen and thrombocytopenia. Ultrasonography and magnetic resonance imaging revealed multiple space-occupying lesions in the spleen. She was diagnosed as having Gaucher's disease based on the low level of beta-glucosidase activity in leukocytes and Gaucher's cells present in bone marrow aspirate. Severe hypersplenism necessitated splenectomy. Pathological studies of the excised spleen, including ultrastructural examinations, demonstrated that multiple space-occupying lesions in the spleen were composed of typical Gaucher cells.

[The assessment of cortical and spongy bone mineral content with quantitative computed tomography. A comparison of measurement sites in relation to certain diseases with metabolic bone disorder]

The CT numbers of cortex at the level of 20 cm (CT20) and spongiosa in the lateral condyle at the level of 2 cm (CT20) proximal from the distal end of the femur, and the bone mineral density of spongiosa in the L3 body (BMD), were obtained by QCT. The study included 43 female patients with rheumatoid arthritis (RA), 71 female patients with primary osteoporosis (OP), 20 female nondialyzed patients with chronic renal failure (CRF:nonHD), 37 hemodialyzed patients (CRF:HD), including 13 parathyroidectomized patients (CRF:HD, PTX), and 10 healthy volunteers. CT20 correlated closely with age in RA. CT02 and BMD correlated closely with age in RA and OP. CT20 and CT02 correlated closely with the duration of hemodialysis in CRF:HD, but not with the duration of disease in RA. The values of CT20 and CT02 in the CRF:HD. PTX group were significantly lower than those in the other CRF groups. BMD in the RA groups was not different from that of healthy volunteers. The CT20 values of the one-third of RA patients older than 60 years were extremely low compared with those of the other two-thirds. The results indicated that BMD was useful in assessing bone mineral content in OP, but not in RA. CT02 and CT20 were useful in assessing bone mineral content in these three diseases, CT20 was especially useful for patients in the CRF:HD group and those with RA older than 60 years, but it was not useful in the CRF:nonHD group.

Cloning and Detection of Chromosomal and Extrachromosomal DNA from Mycoplasmalike Organisms That Cause Yellow Dwarf Disease of Rice

DNA was extracted from rice plants infected with mycoplasmalike organisms (MLOs) causing yellow dwarf disease. DNA of the causal agent was separated from the host DNA by repeated bisbenzimide-CsCl equilibrium density gradient centrifugations. MLO DNA cut by Hin dIII was ligated into plasmid Bluescript II and cloned in Escherichia coli NM522. The DNA inserts were labeled with peroxidase and employed as probes in hybridization. Southern analysis revealed that the insert in pRYD-12 consisted of one, presumably chromosomal, piece of MLO DNA, whereas the insert in pRYD-19, another recombinant plasmid, consisted of one, presumably extrachromosomal, piece of MLO DNA. Cloned DNA probes were successfully applied in dot blot hybridization for the detection of rice yellow dwarf disease MLOs in rice plants and in an insect vector, the green rice leafhopper ( Nephotettix cincticeps ).

[Usefulness of assessing bone mineral content of cortical bone in patients with lingering imbalance of bone metabolism]

The CT numbers of cortex at the level of 20 cm (CT20) and of spongiosa in the lateral condyle at 2 cm (CT02) proximally from the distal end of the femur, and the bone mineral density of spongiosa in L3 body (BMD), were obtained by QCT. The study included 48 patients with rheumatoid arthritis or chronic renal failure as well as 10 healthy volunteers. The relationships of CT20 vs BMD in the regions above and below a critical value of BMD were quite different from each other. Similar relationships were observed in the plot of CT20 vs CT02. The results indicated that the demineralization of cortex was much less than that of spongiosa while the mineral content of spongiosa kept higher than a critical value, but the demineralization of cortex surpassed that of spongiosa once the mineral content of spongiosa had become lower than the critical value. It is necessary to assess bone mineral content of cortex especially in patients with lingering imbalance of bone metabolism.

Abnormal accumulation of vanadium in patients on chronic hemodialysis therapy

Vanadium (V) has been reported to inhibit a number of enzyme activities such as those of Na(+)-K(+)-ATPase. The main excretory pathway of this element is via the kidney. These facts led us to study the V distribution in uremic patients. As a result, hemodialysis patients at our dialysis center exhibited extremely high levels of serum V (23.9 +/- 11.3 ng/ml, n = 43) as compared with healthy adults. Nondialysis patients did not show increased serum V concentrations. The V contents were significantly elevated in the skin and in the aortae of hemodialysis patients. It was found that the tap water from Kanagawa prefecture, Japan, had the highest V concentrations among the 21 cities in Japan and the US. In conclusion, oral ingestion of V-contaminated water has likely caused an accumulation of the metal in patients with end-stage renal failure.

Quantitative computed tomographic evaluation of femoral bone mineral content in renal osteodystrophy compared with radial photon absorptiometry

The computed tomography (CT) numbers of cortical bone at the level of 20 cm (CT20) and of spongiosa in the lateral condyle at the level of 2 cm (CT02) from the distal end of the femur were obtained by a quantitative CT method and compared with the bone mineral density of mostly cortical bone within the radius (BMD) by photon absorptiometry. The study included 47 patients with chronic renal failure not dialyzed or induced to regular hemodialysis within 4 weeks of the study (group 1), 28 patients on regular hemodialysis for more than one month (group 2), and ten healthy volunteers (group 3). The measures of bone mineral content (BMC), namely CT20, CT02, and BMD, were compared in terms of their abilities to distinguish members in the various groups. For group 1 and group 3, the greatest variation in BMC was in the difference in CT02, which was primarily a measurement of the BMC of spongiosa. For groups 1 and 2, the greatest variation was in the difference in BMD, which was primarily a measurement of the BMC of cortex. The reproducibility of CT02 was estimated as almost equal to the difference in CT02 values at intervals of 10 months' duration of hemodialysis. The results indicated that CT02 was a useful measurement for evaluating the progress in the early stage of the renal osteodystrophy, and it is recommended that the bone mineral measurement with this QCT method should be performed once or twice a year.

Theory of relative biological effectiveness (RBE) of tritium beta rays: bacteria killing effects of tritiated water

A new model is applied to bacteria exposed to tritiated water. In this model, the relation between the radiation quality, induction of single- and double-strand breaks in DNA and their repair in vivo can be reasonably described in terms of the microdosimetric distribution and the modification factors for single- and double-strand breaks in DNA. First, a mathematical formulation of RBE of tritium beta rays relative to an arbitrary reference radiation for killing effect on bacteria is derived on this model. Typical theoretical results on the survival curve parameters for bacteria exposed to tritiated water and RBE of tritium beta rays relative to 60Co gamma rays are presented. It is found that RBE of tritium beta rays depends on the ability of the cell to repair DNA damage. The present model is applied to the survival of Escherichia coli Bs-1 exposed to tritiated water and 7 MeV electrons. Although the average LET of tritium beta rays is remarkably higher than that of 7 MeV electrons, the experimental result that RBE of tritium beta rays relative to 7 MeV electrons is close to unity, is reasonably explained by the present model.

Radiation quality of tritium beta-rays: microdosimetric distributions for nanometer-size targets in a medium containing tritiated water

To elucidate the characteristics of the action of tritium beta-rays, the following parameters are derived: electron slowing down spectra of primary electrons (beta-rays) and delta-rays in a medium containing tritiated water; and frequency distributions for the microdosimetric quantity j (number of effective primary events per track per target), fj, for nanometer-size targets exposed to tritiated water. Features of the radiation quality of tritium beta-rays are discussed by comparing the present results with those for 60Co gamma-rays and 7 MeV electrons. It is concluded that, although tritium beta-rays, 60Co gamma-rays, and 7 MeV electrons are classified as the same low l.e.t. radiation, the radiation quality of tritium beta-rays is considerably different from those of 60Co gamma-rays and 7 MeV electrons, and has specific features such as a high average l.e.t., a small total electron fluence per unit absorbed dose, and a different microdosimetric distribution, fj, for nanometer-size targets.

Deranged Ca, Al and Mg content in the tissues of patients with chronic renal failure, as measured by non-destructive neutron activation analysis

Ca, Al and Mg content in the bone, aorta, skin and hair of 55 persons was measured by non-destructive neutron activation analysis. The Ca content in the bone of nondialyzed and dialyzed patients was found to decrease. Al and Mg were relatively higher than Ca in the patients compared to the controls. The present study suggests that fluctuation in the content of Al and Mg may have some relation to renal osteodystrophy such as osteomalacia as well as similar and related disorders. Al and Mg content in the aorta, and that of Ca in the hair of uremic patients, were higher than the controls. The mean Ca content in the skin of the patients was 25% higher than the controls. These findings indicate 1) that Al and Mg are possibly related to the advance of osteodystrophy, and 2) that Ca, Al and Mg deposits in the organs of uremic patients are a reflection of metabolic disorders in chronic renal failure.

Theory of survival of bacteria exposed to ionizing radiation. I. X and gamma rays

A new model for the survival of bacteria exposed to ionizing radiation is constructed in the framework of a target theory based on microdosimetric concepts, where single- and double-strand breaks of DNA and their repair in vivo can be described consistently in terms of the microdosimetric quantity j (number of effective primary events per track per target). In this model, the ability of cells to repair DNA damage is taken into consideration in terms of the repair capacities for single- and double-strand breaks of DNA, xi 1 and xi 2 (0 less than or equal to xi 1, xi 2 less than or equal to 1). To apply this model to Escherichia coli K-12 strains with different repair abilities, values of the repair capacity for single-strand breaks, xi 1, were derived from experimental survival curves. The theoretical survival curves for 60Co gamma rays were found to be effectively insensitive to the value of xi 2. Experimental survival curves for the wild-type, uvr, and rec strains of E. coli K-12 were well reproduced in this model. From these results, it is concluded that the theoretical formulation for the survival fraction of bacteria can afford a quantitative method for analysis of the repair process for radiation-induced single-strand breaks in DNA in vivo.

Deranged mineral content in the bone of patients with chronic renal failure, estimated by computed tomography

To evaluate the extent of renal osteodystrophy in patients with chronic renal failure, the CT numbers of the lateral condylus and mid-shaft of the femur were measured. To adjust for variation due to measurement conditions, calibration phantom was simultaneously scanned with the femur. The CT numbers of the lateral condylus were significantly lower than the control in both nondialyzed (p less than 0.005) and dialyzed patients (p less than 0.05). The CT numbers of the mid-shaft of the femur in dialyzed patients correlated significantly to the duration of hemodialysis (r = 0.807, p less than 0.001). In 15 patients subjected to both CT scan and the photon absorptiometry, the CT numbers of the lateral condylus positively correlated to the mineral content of the radial (r = 0.57) and ulnar (r = 0.69) bones as calculated by photon absorptiometry. These results indicate that the CT scan can be used to estimate bone mineral content quantitatively, and is useful tool for evaluating renal osteodystrophy in patients with chronic renal failure.

Microdosimetric distributions for nanometer-size targets in water irradiated with 60Co gamma rays: frequency distributions of effective primary events by individual tracks of electrons

A calculation method of frequency distributions for the microdosimetric quantity j (number of effective primary events per track per target), fj , is presented. fj distributions are calculated for nanometer-size targets in water irradiated with 60Co gamma rays, using degradation spectra of total electrons in water, phi t(E). Further, fractional total electron differential fluences effective to produce j effective primary events, phi t(E, j), are calculated. It is found that the frequency for occurrence of no effective primary event tracks (tracks traversing the target without any effective primary event inside the target) is very large for nanometer-size targets, and that the delta-ray effect on the fj distribution becomes more significant with the decrease of the target size and especially j effective primary events (j greater than or equal to 1) for very small targets are due mostly to delta rays.

Trace element concentrations in hair, fingernails and plasma of patients with chronic renal failure on hemodialysis and hemofiltration

Trace element concentrations in hair and fingernails and plasma of nondialyzed, hemodialyzed and hemofiltered patients with chronic renal failure and healthy volunteers were measured by atomic and flameless atomic absorption spectrophotometry and neutron activation analysis. Plasma aluminum concentrations in all three groups of patients were higher than in the controls. Aluminum levels in plasma and red blood cells were higher in hemofiltered patients than in dialyzed patients. The aluminum concentrations in the hair of both nondialyzed and dialyzed patients was higher than in the controls, while that in the hemofiltered patients it was not. These elevated aluminum concentrations appear to be mainly caused by the use of aluminum-contaminated dialysate. Calcium concentrations in the hair of nondialyzed and dialyzed patients were higher than in the controls. Plasma zinc concentrations in all the patients were lower than the controls, and the concentrations in hemofiltered patients were lower than in the dialyzed patients.

Synthesis and neuroleptic activity of benzamides. Cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-(methylamino)benzamide and related compounds

Three series of benzamides of N,N-disubstituted ethylenediamines (linear alkane-1,2-diamines), 1-substituted 2-(aminomethyl)pyrrolidines, and 1-substituted 3-aminopyrrolidines (cyclic alkane-1,2-diamines) were designed and synthesized as potential neuroleptics. All target compounds were evaluated for their inhibitory effects on apomorphine-induced stereotyped behavior in rats, and a good correlation between structure and activity was found throughout the series. In the linear series (analogues of metoclopramide), introduction of a benzyl group on the terminal nitrogen, rather than an ethyl group, and a methyl group on the p-amino group of metoclopramide both enhanced the activity. The resulting N-[2-(N-benzyl-N-methylamino)ethyl]-5-chloro-2-methoxy-4-(methylamino) benzamide(23) was about 15 times more active than metoclopramide. In the cyclic series, particularly among the benzamides of 1-benzyl-3-aminopyrrolidine, most of the compounds tested were more active than the corresponding linear benzamides. cis-N-(1-Benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-(methylamino) benzamide (YM-09151-2, 55) was the most active among all of the compounds tested, being 13 and 408 times more potent than haloperidol and metoclopramide, respectively. Moreover, compound 55 exhibited a fairly high ratio of antistereotypic activity to cataleptogenicity compared with haloperidol and metoclopramide. It is expected that compound 55 may be used as a potent drug with few side effects in the treatment of psychosis.

Disturbances of trace element concentrations in plasma of patients with chronic renal failure

Plasma concentrations of 6 essential trace elements were measured in undialyzed and hemodialyzed patients with chronic renal failure (CRF) and in healthy volunteers by tube-excited X-ray fluorescence analysis and atomic absorption analysis. The influences of hemodialysis on plasma concentrations of Al, Zn, Cu and Br were also studied. High plasma concentrations of Al and Cu and low concentrations of plasma Zn were found in nondialyzed patients with CRF. Plasma concentrations of Al and Cu increased and Zn and Br decreased in the hemodialyzed patients with CRF. An elevated concentration of plasma Al may be primarily caused by permeation from dialysate across the dialyzer membrane. The use of water produced by reverse osmosis will prevent the elevation of plasma Al concentration in patients with CRF.