Osteoclastogenesis inhibitory factor/osteoprotegerin reduced bone loss induced by mechanical unloading.

Skeletal unloading resulting from space flight and prolonged immobilization causes bone loss. Such bone loss ostensibly results from a rapid increase in bone resorption and subsequent sustained reduction in bone formation, but this mechanism remains unclear. Osteoclastogenesis inhibitory factor/osteoprotegerin (OCIF/OPG) is a recently identified potent inhibitor of osteoclast formation. We studied effects of OPG administration on tail-suspended growing rats to explore the therapeutic potential of OPG in the treatment and prevention of bone loss during mechanical unloading, such as that which occurs during space flight. Treatment with OPG in tail suspension increased the total bone mineral content (BMC g) of the tibia and femur and the total bone mineral density (BMD g/cm2) of the tibia. Moreover, treatment with OPG prevented reduction not only of BMC and BMD, but also of bone strength occurring through femoral diaphysis. Treatment with OPG in tail-suspended rats improved BMC, BMD and bone strength to levels of normally loaded rats treated with vehicle. Treatment with OPG in normally loaded rats significantly decreased urinary excretion of deoxypyridinoline, but the effect of OPG in tail suspension was unclear. These results indicate that OPG may be useful in inhibiting bone loss-engendered mechanical unloading.

Suppression of manganese superoxide dismutase augments sensitivity to radiation, hyperthermia and doxorubicin in colon cancer cell lines by inducing apoptosis.

Increased expression of manganese superoxide dismutase (Mn-SOD), one of the mitochondrial enzymes involved in the redox system, has been shown to diminish the cytotoxic effects of several anti-cancer modalities, including tumour necrosis factor-alpha, ionizing radiation, certain chemotherapeutic agents and hyperthermia. We asked if Mn-SOD is a potential target to augment the sensitivity of cancer cells to various anti-cancer treatments and for this we established stable Mn-SOD antisense RNA expressing cell clones from two human colon cancer cell lines, HCT116 (p53 wild-type) and DLD1 (p53 mutant-type). Suppression of Mn-SOD in HCT116 was accompanied by an increased sensitivity to radiation, hyperthermia and doxorubicin, as compared with findings in controls. The mitochondrial permeability transition, as measured by a decrease of the mitochondrial transmembrane potential was more intensely induced by radiation in HCT116 antisense clones than in the control, an event followed by a greater extent of DNA fragmentation. Apoptosis was also induced by hyperthermia more intensely in HCT116 antisense clones than in the control. On the other hand, DLD1 antisense clones did not exhibit any enhancement of sensitivity to any of these treatments. These data support the possibility that inhibition of Mn-SOD activity renders colon cancer cells with wild-type p53 susceptible to apoptosis induced by radiation, hyperthermia and selected anti-cancer drugs. Therefore, we suggest that Mn-SOD could be a target molecule to overcome the resistance to anti-cancer treatments in some colon cancer cells carrying wild-type p53.

Cytochalasin A inhibits the binding of phenylalanine ammonia-lyase mRNA to ribosomes during induction of phytoalexin in pea seedlings.

Cytochalasin A (CA) blocked the accumulation of phytoalexin and phenylalanine ammonia-lyase (PAL)-protein in pea tissues treated with a fungal elicitor but scarcely affected the PAL-mRNA content. Further analysis showed that CA decreased the PAL-mRNA bound to ribosomes. These results indicate that actin filaments are tightly associated with the translational process of the PAL gene.

Genes expressed in Ascochyta rabiei-inoculated chickpea plants and elicited cell cultures as detected by differential cDNA-hybridization.

In response to the exogenous application of elicitors and attempted invasion by pathogens, plants exhibit a wide range of defense reactions. To understand the defense mechanisms at the level of gene activation and deactivation, differential screenings were performed to isolate cDNA clones which are differentially expressed in pathogen-inoculated resistant chickpea plants and elicitor-treated cell cultures. A plenty of genes were isolated and arranged in 5 groups, namely defense-related pathways, signal transduction pathways, regulation of gene expression, catabolic pathways and primary metabolism. Most of these genes were activated although several genes were also found to be suppressed. We discuss the plausible functions of cDNA products in plant defense responses. The cDNAs provide a variety of tools to investigate molecular mechanisms of defense responses and clearly reflect the massive genomic and metabolic changes which occur during manifestation of antimicrobial defense.

cDNA cloning and gene expression of three small GTP-binding proteins in defense response of chickpea.

The cDNA clones encoding rab type (INR134 and ELR19) and rac type (ELR26) small GTP-binding proteins were isolated from Ascochyta rabiei-inoculated chickpea leaves and the elicitor-treated cell cultures. Rac type ELR26 showed enhanced expression in inoculated leaves indicating correlation with the defense response.

Relationship between muscle fiber pennation and force generation capability in Olympic athletes.

The thickness (TBmt) and fiber pennation angle (TBpen) of triceps brachii as well as isokinetic force developed during elbow extension were measured in Olympic athletes to investigate the relationship between muscle fiber pennation and force generation capability. The subjects were male members of the 1996 Japanese Olympic team who competed in seven different events; 9 wrestlers, 16 soccer players, 11 sprinters, 5 judo athletes, 7 gymnasts, 9 rowers and 18 baseball players. The TBmt and TBpen, measured by a B-mode ultrasound, ranged between 29 mm and 50 mm and between 11 degrees and 30 degrees, respectively, and on average were larger in the judo athletes, wrestlers and gymnasts compared to the other groups. A significant correlation (r=0.580, p < 0.05) was found between TPpen and TBmt per unit of the upper arm length, and so the observed event-related differences in TBpen tended to reflect the differences in TBmt. The isokinetic forces relative to the cross-sectional area (CSA) estimated from TBmt, measured at two constant velocities of 1.05 rad/s (F1.05/CSA) and 3.14 rad/s (F3.14/ CSA), were negatively correlated to the CSA; r=-0.617 (p < 0.05) for F1.05/CSA and r=-0.635 (p < 0.05) for F3.14/CSA. In addition, low but significant negative correlations existed between TBpen and both F1.05/CSA (r=-0.365, p < 0.05) and F3.14/ CSA (r=-0.336, p <0.05). Even when the effect of TBpen was statistically normalized, the F1.05/CSA and F3.14/CSA were still negatively correlated to the CSA, r=-0.530 (p < 0.05) for F1.05/ CSA and r=-0.561 (p < 0.05) for F3.14/CSA. Therefore, at least in the Olympic athletes tested in this study, the magnitude of the pennation angles reflects muscle size, but it does not seem to be a factor that explains extensively the lower F/CSA in athletes with large muscle size.

Association between ion fluxes and defense responses in pea and cowpea tissues.

The glycopeptide elicitor from a pea pathogen, Mycosphaerella pinodes, induced rapid alkalinization and increases in levels of Na+ and K+ ions in the extracellular solution upon contact with pea and cowpea tissues. The presence of monensin, nigericin, lidocaine, quinidine or phenytoin together with the elicitor markedly inhibited these changes, whereas the presence of valinomycin, gramicidin D, tetraethylammonium, CsCl and aminopyridine did not. The production of phytoalexins in pea and cowpea tissues was also strongly inhibited by the simultaneous presence of the former reagents but not of the latter reagents. Inhibitory effects on the production of phytoalexins were diminished when monensin, nigericin or a Na(+)-channel blocker was applied 3 h after the start of treatment with elicitor. Furthermore, orthovanadate and neomycin, which suppress defense responses in both tissues, also inhibited the above mentioned changes. By contrast, the species-specific suppressor from M. pinodes inhibited the elicitor-induced release of Na+ and K+ ions from pea tissues, but, conversely, by itself it elicited either the defense response or the release of Na+ and K+ ions from cowpea tissues. The results indicate that these ion-related changes, in particular the efflux of Na+ and K+ ions, might be closely associated with the signal transduction system for defense responses at the tissue level.

Fat embolism syndrome caused by vegetable oil injection.

We present a case of fat embolism syndrome following vegetable oil injection for augmentation mammaplasty. Although vegetable oil is a stable neutral fat under usual storage conditions, it caused fat embolism and pulmonary injury in this patient. We investigated this mechanism by compound analysis of the injected oil, transbronchial lung biopsy and special staining of alveolar macrophages. This is the first description of the human response to vegetable oil injection. These data should aid in the investigation of the side effects of many types of lipids which may be applied to humans for various purposes in the future.

Organization of the genes encoding chalcone synthase in Pisum sativum.

To analyze the regulation of defense-related genes by signal molecules produced by phytopathogens, we isolated genes that encode chalcone synthase (CHS) in Pisum sativum. We have obtained seven independent genomic clones that contain at least seven classes of CHS genes, identified by the hybridization analysis to CHS cDNA and by the restriction mapping analysis. Two of the genomic clones (clone 5 and 6) each contain two CHS genes in a tandem repeat. The nucleotide sequence analysis of CHS genomic clone 5 revealed that PsCHS1 and PsCHS2 were corresponding genes of the CHS cDNA clones, pCC6 and pCC2, respectively, as reported earlier. Both genes are interrupted by a single intron of 88 nucleotides with identical sequences, although exonic sequences and 5'-flanking sequences are divergent. Nucleotide sequences of the introns in five other classes of CHS genes showed that three classes had an intron of 87 nt with a striking homology to each other, but that the intron of the other two classes of CHS genes showed heterogeneity both in size and nucleotide sequence. 5'-upstream regions of PsCHS1 and PsCHS2 did not show sequence homology except the 31 bp identical sequence that contains the CCTACC motif resembling the box-1 sequence. Both PsCHS1 and PsCHS2 genes are shown to be induced by fungal elicitor by a primer extension analysis and a transient transformation analysis using pea protoplasts prepared from suspension cultured-cells.

[Thrombosis-inducing activity (TIA) in plasma of a patient with lung cancer, which disappeared after radiotherapy].

A 58-year-old man had been suffering from persistent right shoulder pain was admitted following detection of a Pancoast tumor in the right lung. On admission, there was elevation of peripheral platelet count, plasma FDP and fibrinogen levels and thrombosis-inducing activity (TIA) was detected in his plasma. After receiving 30 Gy of Liniack, the mass shadow and the shoulder pain disappeared, which was accompanied by the normalization of laboratory data and the disappearance of TIA from plasma. However, plasma TIA became positive again one month later, in association with reappearance of shoulder pain and elevation of FDP and fibrinogen levels, which were considered due to recurrence of the tumor, 30 Gy of Liniack together with thermotherapy was again given. There was no subsequent recurrence of tumor, nor TIA has been detected for more than 3 years.

[Formation of experimental obesity by Crisco].

Randomized male litter S.D. rats (weight: about 60 g, 1 group: 10 rats) were used. By using Crisco (hydrogenated cotton seed oil) within the limits of 10 approximately 60%, the intake of the 30% group was high and a good incidence rate of obesity (about 100%) was obtained in the 6 month experiment. In the 30% group, increases of wet weight in perirenal retroperitoneal and subcutaneous fat depots, increases of the number and diameter of fat cells (perirenal retroperitoneal fat depot), elevations of liver fat % and serum insulin level, and a fall of liver phosphoenolpyruvate carboxykinase activity were observed in the 3 month experiment.