31 research outputs found

    Prediagnostic Plasma Vitamin D Metabolites and Mortality among Patients with Prostate Cancer

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    Laboratory evidence suggests that vitamin D might influence prostate cancer prognosis.We examined the associations between prediagnostic plasma levels of 25(OH)vitamin D [25(OH)D] and 1,25(OH)(2) vitamin D [1,25(OH)(2)D] and mortality among 1822 participants of the Health Professionals Follow-up Study and Physicians' Health Study who were diagnosed with prostate cancer. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total mortality (n = 595) and lethal prostate cancer (death from prostate cancer or development of bone metastases; n = 202). In models adjusted for age at diagnosis, BMI, physical activity, and smoking, we observed a HR of 1.22 (95% CI: 0.97, 1.54) for total mortality, comparing men in the lowest to the highest quartile of 25(OH)D. There was no association between 1,25(OH)(2)D and total mortality. Men with the lowest 25(OH)D quartile were more likely to die of their cancer (HR: 1.59; 95% CI: 1.06, 2.39) compared to those in the highest quartile (P(trend) = 0.006). This association was largely explained by the association between low 25(OH)D levels and advanced cancer stage and higher Gleason score, suggesting that these variables may mediate the influence of 25(OH)D on prognosis. The association also tended to be stronger among patients with samples collected within five years of cancer diagnosis. 1,25(OH)(2)D levels were not associated with lethal prostate cancer.Although potential bias of less advanced disease due to more screening activity among men with high 25(OH)D levels cannot be ruled out, higher prediagnostic plasma 25(OH)D might be associated with improved prostate cancer prognosis

    Peripheral nervous system manifestations in a Sandhoff disease mouse model: nerve conduction, myelin structure, lipid analysis

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    <p>Abstract</p> <p>Background</p> <p>Sandhoff disease is an inherited lysosomal storage disease caused by a mutation in the gene for the β-subunit (<it>Hexb </it>gene) of β-hexosaminidase A (αβ) and B (ββ). The β-subunit together with the GM2 activator protein catabolize ganglioside GM2. This enzyme deficiency results in GM2 accumulation primarily in the central nervous system. To investigate how abnormal GM2 catabolism affects the peripheral nervous system in a mouse model of Sandhoff disease (<it>Hexb-/-</it>), we examined the electrophysiology of dissected sciatic nerves, structure of central and peripheral myelin, and lipid composition of the peripheral nervous system.</p> <p>Results</p> <p>We detected no significant difference in signal impulse conduction velocity or any consistent change in the frequency-dependent conduction slowing and failure between freshly dissected sciatic nerves from the <it>Hexb</it>+/- and <it>Hexb</it>-/- mice. The low-angle x-ray diffraction patterns from freshly dissected sciatic and optic nerves of <it>Hexb</it>+/- and <it>Hexb</it>-/- mice showed normal myelin periods; however, <it>Hexb</it>-/- mice displayed a ~10% decrease in the relative amount of compact optic nerve myelin, which is consistent with the previously established reduction in myelin-enriched lipids (cerebrosides and sulfatides) in brains of <it>Hexb-/- </it>mice. Finally, analysis of lipid composition revealed that GM2 content was present in the sciatic nerve of the <it>Hexb</it>-/- mice (undetectable in <it>Hexb</it>+/-).</p> <p>Conclusion</p> <p>Our findings demonstrate the absence of significant functional, structural, or compositional abnormalities in the peripheral nervous system of the murine model for Sandhoff disease, but do show the potential value of integrating multiple techniques to evaluate myelin structure and function in nervous system disorders.</p

    Dietary restriction reduces angiogenesis and growth in an orthotopic mouse brain tumour model

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    Diet and lifestyle produce major effects on tumour incidence, prevalence, and natural history. Moderate dietary restriction has long been recognised as a natural therapy that improves health, promotes longevity, and reduces both the incidence and growth of many tumour types. Dietary restriction differs from fasting or starvation by reducing total food and caloric intake without causing nutritional deficiencies. No prior studies have evaluated the responsiveness of malignant brain cancer to dietary restriction. We found that a moderate dietary restriction of 30–40% significantly inhibited the intracerebral growth of the CT-2A syngeneic malignant mouse astrocytoma by almost 80%. The total dietary intake for the ad libitum control group (n=9) and the dietary restriction experimental group (n=10) was about 20 and 13 Kcal day−1, respectively. Overall health and vitality was better in the dietary restriction-fed mice than in the ad libitum-fed mice. Tumour microvessel density (Factor VIII immunostaining) was two-fold less in the dietary restriction mice than in the ad libitum mice, whereas the tumour apoptotic index (TUNEL assay) was three-fold greater in the dietary restriction mice than in the ad libitum mice. CT-2A tumour cell-induced vascularity was also less in the dietary restriction mice than in the ad libitum mice in the in vivo Matrigel plug assay. These findings indicate that dietary restriction inhibited CT-2A growth by reducing angiogenesis and by enhancing apoptosis. Dietary restriction may shift the tumour microenvironment from a proangiogenic to an antiangiogenic state through multiple effects on the tumour cells and the tumour-associated host cells. Our data suggest that moderate dietary restriction may be an effective antiangiogenic therapy for recurrent malignant brain cancers

    Influence of caloric restriction on motor behavior, longevity, and brain lipid composition in Sandhoff disease mice.

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    Caloric restriction (CR), which improves health and increases longevity, was studied as a therapy in a hexosaminidase beta knockout mouse model of Sandhoff disease (SD), an incurable neurodegenerative disease involving accumulation of brain ganglioside GM2 and asialo-GM2 (GA2). Adult mice were fed a rodent chow diet either ad libitum (AL) or restricted to reduce body weight by 15-18% (CR). Although GM2 and GA2 were elevated, no significant differences were seen between the Hexb-/- and the Hexb+/- mice for most brain phospholipids and cholesterol. Cerebrosides and sulfatides were reduced in the Hexb-/- mice. In addition, rotorod performance was significantly worse in the Hexb-/- mice than in the Hexb+/- mice. CR, which decreased circulating glucose and elevated ketone bodies, significantly improved rotorod performance and extended longevity in the Hexb-/- mice but had no significant effect on brain lipid composition or on cytoplasmic neuronal vacuoles. The expression of CD68 and F4/80 was significantly less in the CR-fed than in the AL-fed Hexb-/- mice. We suggest that the CR delays disease progression in SD and possibly in other ganglioside storage diseases through anti-inflammatory mechanisms

    Hazards ratios (HRs) and 95% confidence intervals (CIs) for total mortality and lethal prostate cancer among prostate cancer patients by quartiles of vitamin D metabolites, combining HPFS and PHS (N = 1822).

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    1<p>Crude mortality rate.</p>2<p>HR1: adjusted for age at diagnosis, body mass index, physical activity, and smoking; HR2: adjusted for age at diagnosis, body mass index, physical activity, smoking, and Gleason score; HR3: adjusted for age at diagnosis, body mass index, physical activity, smoking, Gleason score, and TNM stage; 25(OH)D and 1,25(OH)<sub>2</sub>D were mutually adjusted.</p

    Vitamin D Receptor Protein Expression in Tumor Tissue and Prostate Cancer Progression

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    BACKGROUND: Higher Gleason grade is associated with prostate cancer mortality; however, there is significant heterogeneity in this association. We evaluated whether vessel morphology, a biomarker of angiogenesis, aided in distinguishing mortality risks among men with high Gleason grading. METHODS: We characterized vessel morphology (area and irregularity) among 511 patients diagnosed with prostate cancer during 1986 to 2000, re-reviewed Gleason grade, and followed men through 2012. Men were grouped according to integrated vessel lumen irregularity and vessel area across Gleason grade. The more angiogenic group was identified as those with more irregular vessel lumen and smaller vessel area. Crude rates (95 % confidence intervals) and survival probability were estimated across Gleason grade and vessel morphology. RESULTS: During a median 14-year follow-up, 62 men developed bone metastases or died of prostate cancer. Lethality rates were uniformly low within Gleason grade categories 6 and 7(3 + 4), regardless of vessel morphology. However, among men with Gleason grades of 7(4 + 3) or 8-10, the more angiogenic group was associated with fourfold higher risk of lethal outcomes compared to those with less angiogenic potential. Ten-year survival probability ranged from 95 to 74 % according to the extent of vessel morphology (p < 0.0001, log-rank test). CONCLUSIONS: Vessel morphology may aid Gleason grading in predicting prostate cancer mortality risks among men diagnosed with high-grade Gleason cancers
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