Adolescent exercise associated with long-term superior measures of bone geometry: a cross-sectional DXA and MRI study

OBJECTIVE

To investigate whether childhood sports participation, particularly weight-bearing sports, has any effect on bone mineral content (BMC), areal bone mineral density (aBMD) and bone geometric characteristics in middle-aged postmenopausal women. Design/

SETTING

In this cross-sectional comparison of two groups, 46 middle-aged women (mean age, 60.2 (SD 5.6) years; range, 52-73 years) were grouped according to sport participation during growth: weight-bearing sports, including high-impact weight-bearing activities; and low-impact non-weight-bearing sports or no participation.

MAIN OUTCOME MEASURES

Dual energy X-ray absorptiometry (DXA)-measured BMC, aBMD in the lumbar spine and femur. Magnetic resonance imaging (MRI) determined bone geometric characteristics in the femur, such as femoral mid-diaphyseal cross-sectional area, periosteal and endosteal perimeters and maximum and minimum second moment of area.

RESULTS

Postmenopausal middle-aged women with participation in weight-bearing sports during junior high to high school (12-18 years old) displayed significantly greater BMC in both lumbar spine and femoral neck regions, and also significantly greater femoral mid-diaphyseal bone cross-sectional area, periosteal perimeter and maximum and minimum second moment of area than the non-weight-bearing sports group.

CONCLUSIONS

Adolescent weight-bearing exercise exerts preservational effects on femoral mid-diaphyseal size and shape, while DXA-measured BMC effectively identified the same tendency. Weight-bearing exercise in youth affects bone, and these effects may be preserved as BMC, geometric and structural advantages even after 40 years.

Fine mapping and DNA fiber FISH analysis locates the tobamovirus resistance gene L3 of Capsicum chinense in a 400-kb region of R-like genes cluster embedded in highly repetitive sequences

The tobamovirus resistance gene L(3) of Capsicum chinense was mapped using an intra-specific F2 population (2,016 individuals) of Capsicum annuum cultivars, into one of which had been introduced the C. chinense L(3) gene, and an inter-specific F2 population (3,391 individuals) between C. chinense and Capsicum frutescence. Analysis of a BAC library with an AFLP marker closely linked to L(3)-resistance revealed the presence of homologs of the tomato disease resistance gene I2. Partial or full-length coding sequences were cloned by degenerate PCR from 35 different pepper I2 homologs and 17 genetic markers were generated in the inter-specific combination. The L(3) gene was mapped between I2 homolog marker IH1-04 and BAC-end marker 189D23M, and located within a region encompassing two different BAC contigs consisting of four and one clones, respectively. DNA fiber FISH analysis revealed that these two contigs are separated from each other by about 30 kb. DNA fiber FISH results and Southern blotting of the BAC clones suggested that the L(3) locus-containing region is rich in highly repetitive sequences. Southern blot analysis indicated that the two BAC contigs contain more than ten copies of the I2 homologs. In contrast to the inter-specific F2 population, no recombinant progeny were identified to have a crossover point within two BAC contigs consisting of seven and two clones in the intra-specific F2 population. Moreover, distribution of the crossover points differed between the two populations, suggesting linkage disequilibrium in the region containing the L locus.

Long pulse production of high current D(-) ion beams in the JT-60 negative ion source

The first long pulse production of high power D(-) ion beams has been demonstrated in the JT-60 U negative ion sources, each of which was designed to produce 22 A, 500 keV D(-) ion beams. Voltage holding capability and the grid power loading were examined for long pulse production of high power D(-) ion beams. From the correlation between voltage holding and the light intensity of cathodoluminescence from the Fiber Reinforced Plastic insulators, the acceleration voltage for stable voltage holding capability was found to be less than 320-340 kV where the light was sufficiently suppressed. By tuning the extraction voltage, the grid power loadings in the ion sources were decreased to the allowable levels for long pulse injection without a significant reduction of the beam power. After tuning the acceleration and extraction voltages, D(-) ion beams of 12.5 and 9.8 A were produced at 340 keV with cesium seeding at a rate of approximately 14 microg/s into the ion sources. The pulse duration of these D(-) ion beams was extended step by step, and then was successfully extended up to 18 s without degradation of the negative ion production. The D(-) ion beams were neutralized to yield 3.6 MW D(0) beams by a gas cell, and then injected into the JT-60 U plasma. Further, a slight reduction of D(-) ion beam power allowed the longer injection duration of 21 s at a D(0) beam power of 3.2 MW. The success in the long pulse production of a high power D(-) ion beam shows that negative ion beams can be produced during a few tens of seconds without degradations of negative ion production and the voltage holding in a large Cs-seeded negative ion source.

Activation of caspase 3, 9, 12, and Bax in masseter muscle of mdx mice during necrosis

The mdx mouse, a model of muscular dystrophy, lacks dystrophin, a cell membrane protein. It is known that the lack of dystrophin causes muscle fiber necrosis from 2 weeks after birth, and the majority of necrotic muscle fibers are replaced by regenerated muscle fibers by 4 weeks after birth. A recent study indicated the possibility that mitochondria-mediated intracellular stress, a phenomenon similar to apoptosis, may be produced during muscle fiber necrosis, but did not analyze endoplasmic reticulum-mediated intracellular stress. Therefore, we examined the expression of the caspase-12 gene involved in the endoplasmic reticulum stress pathway and the Bax, caspase-9, and caspase-3 genes involved in the mitochondrial stress pathway in the mdx masseter muscle. We found over-expression of caspase-12 in cells at 2-3 weeks after birth when muscle fiber necrosis was not prominent. This suggests that stress occurs in the endoplasmic reticulum to maintain cell morphology in the absence of dystrophin. In addition, Bax was abundantly expressed in the mdx masseter muscle at 3 weeks after birth, and the expression of caspase-9 and -3 was prominent at 3-4 weeks after birth when necrosis and regeneration were marked. These results indicate that endoplasmic reticulum and mitochondrial stresses are produced during necrosis of the mdx masseter muscle, and suggest that these events are a phenomenon similar to apoptosis.

A novel DISC1-interacting partner DISC1-Binding Zinc-finger protein: implication in the modulation of DISC1-dependent neurite outgrowth

Disrupted-in-schizophrenia 1 (DISC1) is a gene disrupted by a (1;11) (q42.1;q14.3) translocation that segregates with major psychiatric disorders in a Scottish family. To investigate how DISC1 confers susceptibility to psychiatric disorders, we previously identified fasciculation and elongation protein zeta-1 and Kendrin as DISC1-interacting molecules in a yeast two-hybrid screen of a human brain complementary DNA library. Here, we have further identified a novel DISC1-interacting protein, termed DISC1-Binding Zinc-finger protein (DBZ), which has a predicted C(2)H(2)-type zinc-finger motif and coiled-coil domains. DBZ was co-immunoprecipitated with DISC1 in lysates of PC12 cells and rat brain tissue. The domain of DISC1 interacting with DBZ was close to the translocation breakpoint in the DISC1 gene. DBZ messenger RNA (mRNA) was expressed in human brains, but not in peripheral tissues. In situ hybridization revealed high expression of DBZ mRNA in the hippocampus, olfactory tubercle, cerebral cortex and striatum in rats. Because this pattern of localization was similar to that of the pituitary adenylate cyclase (PAC(1)) receptor for pituitary adenylate cyclase-activating polypeptide (PACAP), which has recently been implicated in neuropsychological functions, we examined whether DISC1/DBZ interaction was involved in the PACAP signaling pathway. PACAP upregulated DISC1 expression and markedly reduced the association between DISC1 and DBZ in PC12 cells. A DISC1-binding domain of DBZ reduced the neurite length in PC12 cells after PACAP stimulation and in primary cultured hippocampal neurons. The present results provide some new molecular insights into the mechanisms of neuronal development and neuropsychiatric disorders.

Dehydroepiandrosterone and its derivatives: potentially novel anti-proliferative and chemopreventive agents

Dehydroepiandrosterone (DHEA) is the most abundant adrenal androgenic steroid in young adult humans. The physiological functions of DHEA in preventing human carcinogenesis are still controversial, but a lot of reports have shown that pharmacological doses of DHEA show chemopreventive and anti-proliferative effects on tumors in rodents. Although a therapeutic dose of DHEA has been reported to promote hepatocarcinogenesis in rats due to peroxisomal proliferation, it remains unclear whether DHEA is a peroxisome proliferator in human liver. The chemopreventive and anti-proliferative effects of DHEA are not explained by a single mechanism, and at least four mechanisms seem to contribute to these effects: 1) depletion of NADPH and ribose-5-phosphate due to the inhibition of glucose-6-phosphate dehydrogenase activity, 2) suppression of cholesterol biosynthetic pathway by inhibition of HMG-CoA reductase, 3) interference with cell proliferation signaling pathways, and 4) suppression of nitric oxide generation through down-regulation of nitric oxide synthase II. In addition to studies of the mechanisms underlying the anti-neoplastic effects, searches for more potent and less androgenic DHEA derivatives are ongoing. A small amount of DHEA is endogenously metabolized to 7-oxygenated DHEA, and this may represent a metabolic pathway to more potent steroid hormones. Androsterone, epiandrosterone and etiocholanolone have been considered to be merely inactive end products of DHEA, but may in fact be physiological effectors in their own right. In addition, DHEA analogs such as 3beta-methyl-5-androsten-17-one, 16alpha-fluoro-5-androsten-17-one and 16alpha-fluoro-5alpha-androstan-17-one have been synthesized and shown to be more effective inhibitors of tumor growth, compared with DHEA itself. However, to design potent and safe DHEA derivatives, identification of the DHEA receptor and clarification of the mechanisms of DHEA action are required.

Detection of human papillomavirus type 34 in Bowen's disease on the pubic area

We describe an 86-year-old man with Bowen's disease on the pubic area. The lesion was clinically a black-brownish keratotic nodule resembling seborrheic keratosis. Histopathological findings showed those of Bowen's disease and harboured human papillomavirus type 34 DNA. Genital, but not skin, human papillomaviruses are responsible for Bowen's disease on the skin.

Promoter region polymorphism of macrophage migration inhibitory factor is strong risk factor for young onset of extensive alopecia areata

We have demonstrated that serum macrophage migration inhibitory factor (MIF) was significantly elevated in patients with extensive alopecia areata (AA). Recently, functional polymorphisms have been identified in the MIF promoter region. To address the functional and prognostic relevance of the -173G/C and -794[CATT]5-8 repeat polymorphisms in MIF genes in patients with extensive AA, 113 patients with extensive AA and 194 healthy controls were genotyped. We found that MIF-173*C was a risk factor for early onset (<20 years) of extensive AA (odds ratio for GC heterozygotes with -173G/C was 4.88 (95% CI, 2.04-11.8), P=0.00038; odds ratio for CC homozygotes with -173G/C was 10.42 (95% CI, 2.56-43.5), P=0.0011). We found no statistically significant differences in the genotype frequencies of the -794[CATT]5-8 repeat polymorphism and extensive AA. These results suggest that polymorphisms within the MIF-173*C allele confer an increased risk of susceptibility to the extensive forms of AA, especially with an early onset of disease. MIF is therefore suggested to be closely implicated in the pathogenesis of the more extensive forms of AA.

Localization and function of Arf family GTPases

Arfs are a family of Ras-related GTP-binding proteins that function in the regulation of membrane trafficking and structure. The six mammalian Arf proteins are expressed ubiquitously and so it is anticipated that each will have a distinct localization and function within the cell. It has been assumed that much of this specificity will be defined by determining which regulators of Arfs, the GEFs (guanine nucleotide-exchange factors) and GAPs (GTPase-activating proteins) function with which Arf proteins. Although in vitro assays may indicate Arf preferences for the numerous Arf GEFs and GAPs that have been identified, in the cell the different Arfs, GEFs and GAPs are targeted to specific compartments where they carry out their functions. We have embarked on studies to define regions of the Arf1 and Arf6 proteins that determine their sites of action and specific activities at the Golgi and plasma membrane respectively. Chimaeras were made between Arf1 and Arf6 in order to identify regions of the protein that contributed to targeting and function. Whereas Arf6 is targeted to the plasma membrane through multiple regions along the protein, we have found a Golgi-targeting region in Arf1 that is sufficient to target Arf6 to the Golgi complex.

Disrupted-In-Schizophrenia 1, a candidate gene for schizophrenia, participates in neurite outgrowth

Disrupted-In-Schizophrenia 1 (DISC1) was identified as a novel gene disrupted by a (1;11)(q42.1;q14.3) translocation that segregated with schizophrenia in a Scottish family. Predicted DISC1 product has no significant homology to other known proteins. Here, we demonstrated the existence of DISC1 protein and identified fasciculation and elongation protein zeta-1 (FEZ1) as an interacting partner of DISC1 by a yeast two-hybrid study. FEZ1 and its nematode homolog are reported to represent a new protein family involved in axonal outgrowth and fasciculation. In cultured hippocampal neurons, DISC1 and FEZ1 colocalized in growth cones. Interactions of these proteins were associated with F-actin. In the course of neuronal differentiation of PC12 cells, upregulation of DISC1/FEZ1 interaction was observed as along with enhanced extension of neurites by overexpression of DISC1. The present study shows that DISC1 participates in neurite outgrowth through its interaction with FEZ1. Recent studies have provided reliable evidence that schizophrenia is a neurodevelopmental disorder. As there is a high level of DISC1 expression in developing rat brain, dysfunction of DISC1 may confer susceptibility to psychiatric illnesses through abnormal development of the nervous system.

Induced HMGA1a expression causes aberrant splicing of Presenilin-2 pre-mRNA in sporadic Alzheimer's disease

The aberrant splicing isoform (PS2V), generated by exon 5 skipping of the Presenilin-2 (PS2) gene transcript, is a diagnostic feature of sporadic Alzheimer's disease (AD). We found PS2V is hypoxia-inducible in human neuroblastoma SK-N-SH cells. We purified a responsible trans-acting factor based on its binding to an exon 5 fragment. The factor was identified as the high mobility group A1a protein (HMGA1a; formerly HMG-I). HMGA1a bound to a specific sequence on exon 5, located upstream of the 5' splice site. HMGA1a expression was induced by hypoxia and the protein was accumulated in the nuclear speckles with the endogenous splicing factor SC35. Overexpression of HMGA1a generated PS2V, but PS2V was repressed by cotransfection with the U1 snRNP 70K protein that has a strong affinity to HMGA1a. HMGA1a could interfere with U1 snRNP binding to the 5' splice site and caused exon 5 skipping. HMGA1a levels were significantly increased in the brain tissue from sporadic AD patients. We propose a novel mechanism of sporadic AD that involves HMGA1a-induced aberrant splicing of PS2 pre-mRNA in the absence of any mutations.

Activation of defense-related gene expression and systemic acquired resistance in cucumber mosaic virus-infected tobacco plants expressing the mammalian 2'5'oligoadenylate system

Tobacco plants expressing the mammalian 2'5'oligoadenylate system (2-5A system) exhibit resistance to cucumber mosaic virus (CMV). Here, to characterize the molecular aspect of the resistance to CMV in 2-5A system-expressing tobaccos, the activation of defense-related genes and systemic acquired resistance (SAR) as the markers for the hypersensitive resistance (HR), were elucidated. Northern hybridization analysis indicated that the expression of four pathogenesis-related (PR) protein genes and five HR-related genes were induced in CMV-infected tobaccos expressing 2-5A system. Furthermore, the induction of SAR against Pseudomonas syringae pv. tabaci as second challenge, was observed on CMV-inoculated tobaccos expressing 2-5A system. These results suggested that the resistance to CMV in tobacco expressing 2-5A system is associated with the establishment of an HR-like response.

[Resected cases with primary lung cancer after preoperative high dose irradiation]

After greater than 60 gray (Gy) irradiation, we performed the pulmonary resection in the 18 primary lung cancer cases. The mean irradiation dose to the tumor was 68.2 (range 60-101) Gy, and the mean irradiation dose to the bronchial stump was 47.1 (range 0-82) Gy. Median time from end of irradiation to surgical resection was 136 (range 20-894) days. One partial resection, 9 single lobectomies, 3 double lobectomies, and 5 pneumonectomies were done. Mainly, we closed the bronchial stump by the automatic stapling device and additional hand suturing. The bronchial stump was covered in the 12 cases by the owner stalk thymus, the intercostals muscular flap, the omentum flap, and et al. The major postoperative complications due to preoperative irradiation were not seen. Bronchopleural fistulas did not occur. Pathologically, the wall of the submucosal capillary vessels were getting thick in the patients operated more than 3 months later after irradiation. In such cases with the decrease of the blood flow, the bronchial stump should be covered. The pulmonary resection after the high dose irradiation was considered to be tolerable.

[Angiosarcoma arised from a solitary schwannoma of the chest wall]

Angiosarcomas rarely develop within a peripheral nerve or a peripheral nerve sheath tumor. A 68-year-old woman was admitted for right hemothorax. She had suffered from the left thoracic empyema and the right chest wall tumor which had been regarded as schwannoma clinically. Anemia got serious due to continuous bloody effusion. Although bleeding point was not detected by thoracotomy. The right chest wall tumor was resected. Postoperatively bloody effusion still drained continuously, she died ten days after the operation. Resected tumor was almost necrotized. The tumor was diagnosed as angiosarcoma pathologically, in which a part of schwannoma component resided. It is indicated that angiosarcoma in this case arised from degenerated schwannoma. It is necessary to consider angiosarcoma, rarely arised from degenerated schwannoma, during conservative, long-term observation on the care of schwannoma.

Effects of the beta3 adrenergic receptor agonist on developmental obesity in oophorectomized rats

In this study, we evaluated the anti-obesity effects of selective beta3 adrenergic receptor agonist (ARa) and/or a diet in oophorectomized (OVX) treatment in obese rats. Ten-week-old female Sprague-Dawley rats were divided into 4 groups: (1) OVX; (2) OVX treated with beta3 ARa, BRL 35 135; (3) sham-operated controls (sham group); (4) sham-treated with beta3 ARa (sham+ARa group). These four groups were divided into two groups, one on ad libitum diet, and the other on a diet of limited chow. The effects of beta3 ARa on body weight, intraabdominal fat weight, adipocyte volume, serum lipid content, and serum leptin were measured after 4 weeks had been completed. On both the ad libitum and the limited diet, ARa significantly reduced the ratio of intraabdominal fat and body weight (IAF ratio) regardless whether in the OVX or sham group, although ARa had no influence on weight gain. On the ad libitum diet, the serum leptin was significantly increased after OVX, and significantly reduced after ARa administration. ARa significantly reduced the volume of intraabdominal adipocytes. We conclude that ARa reduces intraabdominal fat without reducing body weight in oophorectomized rats. The serum parameter affected differently to rats on the ad libitum diet and on the limited diet.

The effect of multiple pregnancies on lumbar bone mineral density in Japanese women

OBJECTIVE

To elucidate the effect of multiple pregnancies on lumbar spine bone mineral density (BMD).

METHODS

The BMD of the lumbar spines (L2-L4) of 1,113 healthy women was measured within 7 days of childbirth. In addition 113 women had spine BMD measurements after their next delivery.

RESULTS

In the cross-sectional study, there was no apparent effect of parity on lumbar BMD. In the longitudinal study, the mean BMD after the next delivery was significantly higher than that after the initial delivery (1.019 +/- 0.115 g/cm(2) vs. 1.006 +/- 0.117 g/cm(2), P = 0.001, paired t test) with a percent change (DeltaBMD%) of 1.4 +/- 4.2%. Multiple regression analysis to identify independent predictors of DeltaBMD% showed a negative correlation with maternal age at the subsequent delivery (P = 0.033) but no correlation of DeltaBMD% with the length of lactation between the scans.

CONCLUSION

Multiple pregnancies may not reduce maternal lumbar BMD, although the percentage decrease in BMD was greater in older women at the subsequent delivery. The length of lactation between the scans had no effect on these results.

Maintenance of bone mass and mechanical properties after short-term cessation of high impact exercise in rats

Abstract. The effects of cessation of high-impact exercise on bone mass in female Wistar rats was assessed. Fifty 10-week old rats were randomly divided into five groups (n = 10): 4 weeks jump-exercise (4JEX), 4 weeks sedentary control (4S), 8 weeks jump-exercise (8JEX), 4 weeks jump-exercise followed by 4 weeks sedentary (4JEX4S) and 8 weeks sedentary control (8S). The rats were jumped trained 40 times/session, 5 days/week. After 4 weeks or 8 weeks the mass and breaking force in tibia and cross-sectional areas of the tibia were measured. The tibia in the 4JEX and 8JEX groups had significantly greater fat-free dry weight and maximum loads at the fracture tests than those in the 4S and 8S groups. The tibia of 4JEX and 8JEX also had significantly larger cortical area without a significant change in the medullary area at the cross-sectional analysis. Bone mass acquired in 4JEX4S group was retained after cessation of exercise. The results indicate that high-impact jump-exercise, which is osteotropic, leads to an increased cortical bone with enhanced periosteal bone formation, which is also, however, maintained after cessation of exercise. It is therefore suggested that high-impact jump-exercise may provide greater safety margin against disuse-related or/and age-related bone loss and skeletal fragility later in life.

[Clinical study of 33 children with systemic pneumococcal infections]

We retrospectively analyzed 33 cases of children with systemic pneumococcal infections, 22 bacteremia and 11 meningitis, diagnosed and treated in Asahi General Hospital between 1985 and 1999. The median age at diagnosis was 15 months old and the incidence peaked in infants between 7 and 24 months of age (57.6%). Two cases showed low serum IgG2 levels. Fever was a common symptom in all cases and 13 (39.4%) presented convulsions. Meningitis [median age: 10 months] tended to occur, if not significant, in younger children than bacteremia [16 months]. All cases of meningitis were diagnosed 12 hours or later after the onset of fever, though 54.5% of the cases of bacteremia were diagnosed within 12 hours. The cases of meningitis showed statistically lower white blood cell counts [median: 9,700/mm3] and higher CRP levels [median: 25.6 mg/dl] than those of bacteremia [23,900/mm3 and 4.2 mg/dl, respectively] at diagnosis. Although all cases of bacteremia were cured without any sequelae by antibiotic treatment, 3 cases (27.3%) of meningitis died and 4 (36.4%) developed severe neurological sequelae. Our findings suggest that the putative pathogenesis by which pneumococcal meningitis results from bacteremia and, taking in the account of the poor outcome of meningitis, may justify the early antibiotic intervention against pneumococcal bacteremia.

[A case of right pneumonectomy and omentopexy for lung cancer after preoperative irradiation]

A 72-year-old man complaining of cough rejected the operation for squamous cell carcinoma obstructing the right intermediate trunk, therefore he was received 82 Gy (40 Gy and 42 Gy) of radiotherapy. However, the tumor did not decrease, in addition, cough and purulent sputum became severe gradually. We performed right pneumonectomy and omentopexy to prevent bronchial fistula, he had no pulmonary complication. Radiotherapy is a risk factor for postoperative bronchial fistula, omentopexy is useful to prevent it.

Disturbed activation of endoplasmic reticulum stress transducers by familial Alzheimer's disease-linked presenilin-1 mutations

Recent studies have shown independently that presenilin-1 (PS1) null mutants and familial Alzheimer's disease (FAD)-linked mutants should both down-regulate signaling of the unfolded protein response (UPR). However, it is difficult to accept that both mutants possess the same effects on the UPR. Furthermore, contrary to these observations, neither loss of PS1 and PS2 function nor expression of FAD-linked PS1 mutants were reported to have a discernable impact on the UPR. Therefore, re-examination and detailed analyses are needed to clarify the relationship between PS1 function and UPR signaling. Here, we report that PS1/PS2 null and dominant negative PS1 mutants, which are mutated at aspartate residue 257 or 385, did not affect signaling of the UPR. In contrast, FAD-linked PS1 mutants were confirmed to disturb UPR signaling by inhibiting activation of both Ire1alpha and ATF6, both of which are endoplasmic reticulum (ER) stress transducers in the UPR. Furthermore, PS1 mutants also disturbed activation of PERK (PKR-like ER kinase), which plays a crucial role in inhibiting translation during ER stress. Taken together, these observations suggested that PS1 mutations could affect signaling pathways controlled by each of the respective ER-stress transducers, possibly through a gain-of-function.